Full Report V1.3.pdf

CHAPTER 1 INTRODUCTION 1.1 Background Study Pepper or scientifically called as Piper Nigrum L is a species belong to family of Piperaceae. Generally, the origin of this plants are from India and was introduced to Malaysia since 1856. It one of the agriculture sectors in Malaysia that gives higher revenue which Malaysia is in the fifth position in the world production of the pepper. Malaysia is one of the main producers and exporters of pepper (Ravindran, 2000). The state of Sarawak, the main pepper producing region in Malaysia, accounts for more than 90% of the country’s annual production. Black pepper is produced and exported from this state. The other producing areas are Sabah and Peninsular Malaysia. Malaysia’s Pepper harvest begins in May. Table 1.1: The production of pepper berries from 1970-2016 (Chen. YS and Zehnder, Malaysia Pepper Board,2016).

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As mention earlier, Black Pepper is a part from Piperaceae family, that cultivated for its fruit which is usually dried and used as a spice and seasoning. The morphology of the fresh berries when it already matured is can be said in 5.3 mm to 7.8 mm. While for the dried berries, the size can be around 3.5 mm to 5.3 mm. From the fresh berries it can be convert either in black or white pepper berries. The conversion rate for the pepper between 33% for the berries to turn into black and 24% for the berries to turn into white berries. Moreover, pepper that derived precisely as black pepper are in the condition of cooked and dried unripe fruit, while, the white pepper are from the ripe fruit seeds. As for Malaysia is one of the largest countries that be able to produce the pepper and knowingly, Sarawak conquered around 90% of the pepper plantation, the technology that being used to dry the pepper still in traditional way. Basically, farmer dry the berries over the sunlight radiation with using kenaf mat or wooden drying platform as the berries spread it out all over the platform. It can be said as cheap and portable but at the same time they need to face the unexpected weather (raining) and the quality of the pepper berries is not stable and consistent. This kind of technology be able to produce around 100 kg to 300 kg per 5 days if there is no raining and temperature is quite good. The estimation cost for the technology approximately between RM 100 to RM 10000 based on the information from the Malaysia Pepper Board given. Thus, our company EZ Corporation has an idea in manufactured the dryer machine to ease the farmer problem with considering their capability in term of production rates, quality of berries and money. 1.2 Problem Statement Main Problem: In Malaysia, mature harvested pepper berries have undergone drying process in order to preserve the pepper. Drying method enables the treated pepper quality to be preserved. Dehydration is a process of removing moisture content from the food. Typical conventional dehydration method is using hot-air drying for instance is direct sunlight. However, the process is inefficient, not hygienic, time consuming and sometimes the quality of food gets deteriorated. Thus, in this project, our company want to design and assist the smallholder pepper dryer planters especially in Sarawak to improve overall pepper drying process with better food processing

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technologies. The technologies was to introduce safer, fresher and better quality foods with more efficient and economical technology.

1.3 Limitation of Traditional Drying Method The typical conventional dehydrating method have some limitations which are: 1. Weather dependent (Using Direct Sunlight) The typical dehydrating method by using direct sunlight was not the best choose to dry the pepper. That was due to the weather dependent. The Malaysian weather was equatorial weather that hot and humid year-round. Especially during the monsoon season, the production rate will reduce as the pepper drying process was stop processing. The drying process also stop at night. The typical drying system was not 24 hours operated. The product produce by the farmer was not continuous and not fully maximise the everyday production rate. 2. Time Consuming (4-5 days) As the typical conventional drying process was using the direct sunlight, the farmer cannot control the humidity level and temperature level every day. The humidity level and temperature was depend on how good the weather on that day. The typical drying process was take up to 4 or 5 days to dry. This will reduce production rate. The farmer need to wait till the pepper was dry enough to commercialize their product. 3. Inefficient The typical conventional drying process was still using the skilled labour to unload and load the pepper to the drying platform. To distribute the pepper on the surface of the platform also done by the labour. It was not efficient method to maximise the production rate. It was still depend on the human effort to handle the pepper. 4. Not Hygienic The open space area for the drying process was not protect the pepper from the surrounding environment. The pepper will highly exposed and contaminated with the surrounding bacteria. Especially with the Malaysian weather that hot

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and humid year round. It was the best weather for the bacteria to growing up. The quality of the pepper produced by the farmer gets deteriorated. 5. Not Cost Effective The traditional process, which is open air sun drying, is not a cost effective method. This because the farmers need spend money on labour cost to hire some workers to help distribute the pepper on the drying platform and also packaging the pepper. Besides, this method requires a big space of land in order to dry the pepper under the sunlight.

1.4 Objectives Aim: This project aims to assist the smallholder pepper planters in Sarawak to improve overall pepper drying process. Objectives: a. Safety. It is imperative that the machine operate safely so as to promote the wellbeing of people and equipment within the premise and in the nearby communities. b. Meets International Food Safety Standards (CODEX). The machine must comply with the regulations concerning the food safety, Hazard Analysis &Critical Control Points (HACCP) and halal practices if necessary. c. Product Specifications and Production Rate. In order to be profitable, the machine must meet specifications concerning standard product quality and improve drying rate. d. Optimize heat transfer. Optimization of heat to maximize performance and efficiency, reduce maintenance costs and extend the life of the machine. e. Environmental friendly. An efficient energy use and environmental friendly energy resources. f. Economic Machine Operation. It is an economic reality that the machine over long periods of time must be profitable. Thus, the control objectives must be consistent with the economic objectives. g. Originality. Originality in design to formulate suitable solution.

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CHAPTER 2 LITERATURE REVIEW

2.1 Introduction Drying is defined as the application of heat under controlled conditions, to remove the water present in foods by evaporation to yield solid products. It differs from evaporation, which yields concentrated liquid products. The main purpose of drying is to extend the shelf-life of foods by reducing their in-water activity. Micro-organisms which cause food spoilage and decay and many of the enzymes which promote undesired changes in the chemical composition of the food are unable to grow, multiply or function in the absence of sufficient water. 2.2 Black Pepper (Piper Nigrum) Black Pepper, known as the King of Spices, is the most important and most widely used spice in the world. The black pepper of commerce is the dried, mature fruits (commonly called berries) of the tropical, perennial climbing plant Piper nigrum L., which belongs to the family Piperaceae. Black pepper (hereafter the name pepper is used to mean black pepper) is a woody climber, grown in the South Western region of India. The humid tropical evergreen forests bordering the Malabar Coast is the centre of origin and diversity for the King of Spices (Pepper). The Malabar Coast was involved in the cultivation and trade of pepper from very early times. From here pepper was taken to Indonesia, Malaysia and subsequently to other pepper growing countries. Malaysia is one of the major producers and exporters of pepper. The state of Sarawak, the main pepper producing region in Malaysia, accounts for more than 90% of the country’s annual production. Black pepper is produced and exported from this state. The other producing areas are Sabah and Peninsular Malaysia. Malaysia’s Pepper harvest begins in May. The main markets for Malaysian pepper were Japan, China, Taiwan, Korea and Singapore. 5

Black pepper is rightly called the King of Spices, and its position is supreme among spices. This spice with its characteristic pungency and flavour is an ingredient in many food preparations, and at the dining table it is the only spice invariably served. It was used for different purposes by different people in the past, and continue to be so currently and will remain so in future as well. For the civilized people it is a spice, an essential additive to their food.

2.3 Development of Pepper Dryer Technologies Sun dried pepper berries take 4-5 days for proper drying, depending upon the climatic conditions. Sun drying has several limitations. Therefore, the use of artificial dryers become essential. The possible alternate drying technologies are infrared drying, conduction drying, heated air drying, desiccated air drying and refrigerated air drying for agricultural commodities. The use of solar dryers in comparison with open sun drying gave better quality products with lesser drying time. The solar tunnel dryer was developed at the Institute for Agricultural Engineering in the Tropics and Sub-tropics of Hohenheim university, Germany. To simplify the construction and to reduce the production costs, the solar air heater is connected directly to the drying tunnel without additional air ducts. Both the collector and drying tunnel are installed on concrete block substructures to ease loading and unloading of the dryer. The entire floor of both solar air heater and the drying tunnel consists of plastic foam sandwiched between two metal sheets with a groove and tongue system, have a length of 17 meters (10m for tunnel and 7 m for heater) and 2 meters breadth. The entire bottom surface of the solar air heater of the dryer is coated with black paint (90% absorptivity). In the solar tunnel dryer, the crop is spread out on a wire mesh placed 20 mm above the floor, which is covered with a plastic net aimed to sieve the smaller dust and dirt through the holes during drying. The solar air heater and the tunnel are covered with a transparent uv stabilized PE plastic foil 0.2 mm in thickness with a transmissivity of 92% for visible radiation. Two axial flow fans are incorporated in the sandwiched substructure at the back of the air inlet of the solar air heater to suck ambient air into the collector. The capacity of the tunnel ranges from 60 kg to 200 kg wet fruits depending upon the size of the fruit and thickness of the spreading layer (C.M., Peter Pittappillil & Jose, 2002).

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Although solar drying is practiced in large scale, however this method is only limited to the country with high intensity of sunlight. Dry climate and high degree of isolation of the pepper berries from the surrounding air is needed. The duration and drying temperature depends on few factors which is relative humidity, speed of air inside the drying compartment and also the characteristics or drying method of the black pepper. The black pepper has 65% to 70% of moisture content, which should be reduced to 10% of moisture content by adequate drying. Any dried pepper berries with a moisture content with more than 12% moisture content, it is vulnerable to fungal attack. The berries is dried under the sun from 4-7 days until the outer skin of the berries become black and the texture turns wrinkled. The solar cabinet dryer is able to produce the black pepper with black in colour which compared to dull black in direct sunlight method. It can be used to increase the spreading density during drying to reduce the space required for drying process. The dryer design also should give a main focus in moisture removal to improve the efficiency of the drying. This is because even if the temperature and the flow of air is adequate, the drying efficiency is still low because the humidity inside the dryer chamber might reach its top humidity that prevents the water inside the pepper from evaporate and hence reduce the efficiency of the dryer. So that the air with high moisture content should be constantly drawn out from the drying chamber and then been replaced with the fresh air. Drying grains and other agricultural products is a very energy-intensive process. The variation in drying methods and equipment is due to the type of dryer used, airflow rate, drying air temperature, ambient conditions, productconditions and types, and the type of energy used. Solar drying is technically feasible but still not economically competitive at this time. This is because most solar crop dryers employ the services of a back-up during the heavy rains. The air heated in the solar collector moves, either by natural convection or forced by a fan, up through the material being dried. The size of the collector and rate of airflow depends on the amount of material being dried, the moisture content of the material, the humidity in the air, and the average amount of solar radiation available during the drying season. Solar dryers have many configurations sizes and shapes and these are very much influenced by the type of crop to be dried and the quantity of the crop to be dried as well as the drying rate. The Pepper dryer designed was solely operated with solar energy and used natural convection. 7

Figure 2.1: Solar Pepper Dryer

Figure 2.2: Example of pepper dryer

Radio frequency heating is also a way that can be a heating element inside the dryer and it operates under dielectric principles. Disregarding dielectric properties relevant to RF heating can lead to improper heating, occurrence of cold spots or burning of product. The effect of moisture content on dielectric properties of solid or semisolid foods in order to prevent undesirable RF heating has been clarified by some research An investigation on various moisture ranges from the effect of RF heating on the quality of powdered red and black pepper spices was done by S.G Jeong and D.H Kang (2014).

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Below is the schematic diagram of investigation of RF heating and dielectric measurement system.

Figure 2.3: Schematic diagram of RF heating and dielectric measurement system at Seoul National University (Seoul, South Korea). Heat pump dehumidifiers (HPDs) offer several advantages over conventional hot-air dryers for the drying of food products: higher energy efficiency, better product quality, and the ability to operate regardless of ambient weather conditions. In an HPD dryer, the drying takes place in a sealed chamber and the moisture is removed in its liquid state. The source of the heat that is absorbed at the evaporator is the humid air that is drawn from a product during the drying process. The moisture is condensed out of the humid air. The latent heat recovered is released at the condenser of the refrigeration unit and used to reheat the air within the dryer. The system is recirculatory, rather than open. Removal of water in its liquid state allows the latent heat of vaporization to be captured, resulting in higher efficiency. However, because the drying is performed in a sealed chamber, HPD is more suited to batch processing than continuous processing. Lower temperatures may be used in HPD dryers, which may help to improve product quality (Northwest Food Processors Association). The present study investigated the influence of microwave power on the drying kinetics, energy consumption and drying efficiency of green pepper during microwave drying at 180, 240, 300, 360, 420, 480 and 540 W. Seven mathematical models for describing the thin-layer drying behaviour of pepper samples were investigated. The models were compared based on their R2, RMSE and χ2 values between experimental 9

and predicted moisture ratios. By increasing the microwave output powers (180–540 W), the drying time decreased from 9 to 2.5 min. The drying process took place in the falling rate period. The results show that the Midilli model is the most appropriate model for drying behaviour of thin layer pepper samples. A third order polynomial relationship was found to correlate the effective moisture diffusivity with moisture content. The effective moisture diffusivity increased with decrease in moisture content of pepper samples. The average effective diffusivity varied from 8.315 × 10−8 to 2.363 × 10−7 m2/s, over the microwave power range studied, with an energy activation of 14.19 W/g. Energy efficiency increased with increase in microwave power and moisture content. The least specific energy consumption (4.99 MJ/kg water) was at the microwave power of 240 W and the highest (6.80 MJ/kg water) was at 180 W (Darvishi et al., 2014). 2.4 Factor Effects in Improving the Dryer Machine Technologies Generally, principles applied for drying: (a) Hot air drying: Hot air is used as the heating medium and is in direct or indirect contact with the liquid product. The heat transferred from the hot air to the product causes evaporation of the water content.

(b) Surface drying by heat conduction through a heat transfer system (i.e. contact dryers): The heating medium is not in contact with the wet food but separated from it by a heat transfer surface. The heat is transferred by conduction through the surface, and by convection from the hot surface to the food product for evaporating and removing water from the food. This has two main advantages compared to hot air dryers; less air volume is required and therefore thermal efficiency is higher, and the process may be carried out in the absence of oxygen. Controlled drying parameters help to ensure that a food or feed product is shelfstable. However, one single processing deviation can dramatically affect batch results and yield. This may be a result of over drying due to unnoticed process shifts. Today, many food and feed factories are becoming leaner and operations staff has less time to closely monitor dryer performance. Over drying, or drying to water content far below 10

a reasonable shelf stable level, is unfortunately a common practice throughout the food and feed industries. Over drying wastes energy and increases a manufacturer’s carbon footprint. It can also lead to undesirable product characteristics, such as an inconsistent colour or texture. When product is over dried it will take a longer time to cool to a packable temperature. As a result, being able to efficiently control moisture is vitally important for any dryer operation. Hybrid drying techniques can also be used, such as combining vacuum or convective drying with electro-technologies (microwave, radio frequency, infrared heating). Hybrid Technologies such as electro technologies, sonic drying, using superheated steam, and heat pump-assisted drying are some of the examples one should consider. Dilip M, Parikh is president of DPharma Group Inc., Ellicott City, MD, a pharmaceutical technology consulting firm. He is an industrial pharmacist with more than 35 years of industrial experience in R&D, manufacturing, cGMP-complaint facility planning, and operational management at various pharmaceutical companies in Canada and the U.S (Increasing Drying Efficiency | Powder/Bulk Solids, 2014). Drying processes are one of the most energy intensive unit operations. Drying has been reported to account for anywhere from 12 to 20% of the energy consumption in the industrial sector. Typical adiabatic dryers account for about 85% of all industrial dryers, where air is heated by the combustion of fossil fuels prior to being forced through the product. This type of drying requires high-energy inputs, due to the inefficiencies of such dryers. Often, the exhaust air is simply released to the surrounding ambient air. With increasing concern about environmental degradation, it is desirable to decrease energy consumption in all sectors Efficiency calculations are useful when assessing the performance of a dryer, looking for improvements, and in making comparisons between the various classes of dryers which may be alternatives for a particular drying operation. The energy efficiency for convective dryers is usually calculated based on the temperature of the drying medium at the inlet, outlet, and the ambient air temperature. The basic approach to calculating any energy efficiency, K, is to take the ratio of energy required, Er, to energy supplied, Es: K = Er/ Es. When considering opportunities for saving energy, it is necessary to view the system holistically, from energy source to exhaust gas recirculation. Potential energy savings must be weighed against other factors, including capital expenditure, safety, 11

emissions, and product quality. The energy efficiency can be calculated for the drying process as a whole (total energy required and total energy supplied), instantaneous efficiency (energy required and energy supplied at given time), or it may be only for the drying chamber, not including other peripheral energy requirements. Some systems allow for the recycling of exhaust heat, which can greatly increase the overall energy efficiency of the dryer. The minimum quantity of heat that will remove the required water is that needed to supply the latent heat of evaporation, so one measure of efficiency is the ratio of that minimum to the energy actually provided for the process. There are a number of approaches to reduce energy consumption in dryers. For example, the area of contact between air and material, length of the dryer, and the rate at which air moves can all be increased. These factors are best considered during the design of the system and are usually not viable options for retrofit because of space limitations and/or reductions in the rate of system’s output. One effective way to reduce the energy required for the drying process is to use mechanical means, such as filtration, whenever possible to reduce the water content prior to any thermal drying. Drying conditions can be modified or the drying equipment can be modified to increase overall efficiencies. Dryer inputs fit in two categories: those that can be manipulated (e.g., valve, damper, and burner settings, fan speeds, and belt feed rates) and those that are not easily manipulated but that can greatly disturb components of the process (e.g., ambient air temperature and humidity, feedstock composition, and moisture content). During the entire drying process, the gas atmosphere inside the drying apparatus may be monitored and documented continuously with a process gas mass spectrometer. The mass spectrometric data gives important information for optimization of the temperature, pressure and carrier gas parameters in process development, particularly with regard to influencing the sequence of individual drying steps if there are several solvents.

2.5 Holistic topics covered/ Parameter of pepper drying 

Parameter: Drying Temperature of Pepper

An optimal temperature to dry the black pepper into the desired moisture content is needed without destroying or degrade the quality of the black pepper. A high temperature is very important to improve the efficiency of drying in order to remove 12

moisture so that mould will not grow inside the black pepper. Besides, the temperature must be sufficient enough to kills several kind of pathogens. International Pepper Committee (2007) states that pepper should be dried below 60°C to avoid the loss of volatile contents inside the pepper. From here, it should be known that the temperature below 60°C can be used to dry the pepper without causing significant degradation of the pepper quality. On the other hand, high temperature is able to reduce the relative humidity inside the dryer so that the air is capable of absorb more amount of moisture which is evaporated from the pepper. In conclusion, the operating temperature is set to be close to 60°C but lower. Browning and discolouration will occur if the temperature is too high. 

Parameter: Hygiene and Food Standard of Pepper

Also, the black pepper also should be dried in a clean environment, which means the dusty area, dirty area such as farm should be avoided to become a spot for drying (International Pepper Committee, 2007). However, a closed dryer which could be used to protect the pepper from surrounding environment and hence reduce the contamination into the lowest possible level. Optimal temperature also discussed beforehand to kill the bacteria from growing inside the pepper. An adequate air flow introduced inside the dryer can prevent the mould from growing inside the pepper during the drying process. 

Parameter: Moisture Content of Pepper

In order to determine the time to dry the pepper, the moisture content of the pepper is needed. It can be found that the maximum moisture content of the standard Malaysian black pepper is 12% per weight. The moisture content can be obtain by knowing the size of the pepper. Pepper is known as hygroscopic, where it has the ability to absorb moisture from surrounding air. Therefore, the position of the machine too might affect the moisture content of the pepper. For example, in case the pepper has not been taken out while the machine is placed outside, the dew from the surrounding might enter and affect the moisture content of the pepper inside the machine. Then the time taken to dry the pepper might be affected as well and the quality of the pepper will be reduced.

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Parameter: Efficiency of Dryer & Production Rate of Pepper

The efficiency of the dryer need to be considered as well. According to the Malaysian Pepper Board, the normal rate for drying the pepper through direct sundrying process took around 4 to 5 days. The rate actually depends on the weather itself. If the weather is suitable for the drying process, then the time taken for the pepper to dry will be lesser and the production rate will increase. But, since Malaysia has different climate when it can be hot and humid throughout the year, it might be a bit difficult for the farmer to make the sun-drying process especially during rainy weather and will take a longer time for the pepper to dry which then affect the production rate. Therefore, the efficiency of the dryer need to be higher in order to lower the rate of the drying process.

2.6 Benchmarking of the Dryer Machine The project purpose is to assist the smallholder pepper planters in Sarawak to improve overall pepper drying process. Since the targeted customers are farmers who undergo small business, hence, the prior consideration of the design is the price of machine as well as its efficiency. With the help of machine in replacement of traditional way of drying, it is believed that the productivity of pepper business will increase significantly. According to Alibaba website, there are a lot of drying machines available in market nowadays. They are sold at different range prices. However, three of the products in market with different places of origin and price range are selected for benchmarking. Table 1 shows the comparison of drying machines. The first product has the advantages of small size and light weight, besides, it can dry 10 trays of food per batch. It possesses higher productivity as compared to second product. However, second product is energy saving whereby it only requires 416W to operate as compared to the first product, which required 2 times the power needed by the second product. Both product temperature ranges are optimum for dehydration of pepper, which is 60℃ or less. As for the third product, its price is relatively higher than the previous. It possesses high load capacity, which can dry 60 kg of food per batch, however, the temperature range is 60℃ to 140℃, which will destroy the nutrient contents in pepper berries.

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Table 2.1: Benchmarking on Various Products Available in the Market Product Name

10 Trays Black Pepper Drying Machine

Industrial Black Pepper 2017 Competitive Price Drying Machine CT-C Black Pepper Drying Machine

Price

RM 3355

RM 2432-RM 3816

RM 8387- RM 67,096

Dimension

420mm x 380mm x 550mm

325mm x 380mm x 484mm

1380mm x 1200mm x 2700mm

Weight

15.5 kg

10.5kg

820 kg

Heat Power

980 W

416W

6900W

Place of Origin

China

Japan

China

Temperature 35-70

0-80

60-140

Load Capacity

4 Trays

60kg

Product Image

Advantages

10-15 kg (10 Trays) 

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High temperature sealing door to prevent heat loss Stainless steel tray to prevent contamination of food Timer device, easy to operate

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Power Saving Type Noise (36dB) Silent Type Thermal Insulation Cabinet (Polyurethane foam)

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  

Possess both auto control system and computer control system Heating air cycling in oven, enable even and uniform drying Low noise Steady operation Easy access to temperature control

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CHAPTER 3 METHODOLOGY .

3.1 Introduction In order to ensure a fully functioning machine can be produce, it must undergo efficient and systematic design process. Several factors will be considered in building and manufacturing the machine with the most crucial and primary part being the engineering design phase. The flow of design process need to consider the customer needs, develop the conceptual design, create the preliminary design, emphasise detailed design and then come out with final design. Engineering Design is the set of decisions used to determine the form of an object given the functions desired by the customers. In this project, computer aided drawings (CAD) which is Solidwork has been used to drawn the machine 3.2 Problem Definition In this project, the purpose of design and manufactured the machine is to minimize the problems that farmer felt. From using the traditional way to drying the pepper, may be by using our machine with added of improving the technologies it could be help the farmer. Quality of pepper berries and duration of drying rate are the factors effecting in develop the idea in produce the machine. 3.3 Gather Information a) House of Quality Based on the house of quality, the room 5 shows the most important factor that influence the design is the efficiency which determine the performance and drying rate of the dryer. It is then followed by the insulation which helps in trapping the heat from escape into the surroundings. Cost and life cycle is the third specification that the farmer consider so that they can take note 16

of the initial investment whether it is profitable and sustainable. Food Hygiene is the fourth important things so that the product quality is always safe to be consumed. Ventilation is the next aspect which helps in fight the mould attack during the process. The rest is strength and durability, required space and size of the dryer. Some of the engineering specification possess a positive relationship between each other which is beneficial whereas some of it have negative relationship which will become an obstacle for the dryer to function well. The ‘+’ and ‘—’ sign for the roof top of the house of quality shows the relationship, which is called correlation matrix of room 3. Room 6 shows customer assessment between 3 products in the market.

Figure 3.1: House of Quality

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b) Survey research

i.

Internet

Researching via Online Research Method (ORMs) is one of the routes for researchers to gain information by surfing the internet webs. From this method, the research of our conceptual designs can be done. It gives the knowledge and understanding on how to make the drying process to be more efficient than the conventional ways of drying. The disadvantages of the conventional ways had been used to improvise the conceptual designs. The information of latest drying machine can be collected from this method to solve the problem from the conventional drying method.

ii.

Journal

The journals give us the idea to improvise the research as it provides the information from the experiment results regarding to the drying process.

c) Observation research The researcher observes a particular aspect of human behaviour with as much objectivity as possible and records the data. This research method may provide an alternative to various qualitative research methods. In the survey research method, the researcher tends to capture phenomena at the moment. This method is used for sampling data from respondents that are representative of a population and uses a closed ended instrument or open-ended items. From the working during Industrial Training, Apply the knowledge to create the new concept to the drying machine designed.

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3.4 Concept Generation a) FILA The dryer design requirement for pepper dryer have listed down and some ideas to encounter the problem arises for the requirement have also listed down. This is the initial step to generate some possible outcomes that is useful for brainstorming. Table 3.1: FILA table of Drying Chamber Facts  The initial moisture content of pepper is 77% and the final dried pepper should have 12% in moisture.  The drying process must be hygienic.  The size of machine must be compact.  Consider ergonomics factor of farmer.  Mobility of machines.  Environmental friendly machine.

Ideas  Implement weight sensor system to measure the final moisture content.  Design hybrid solar dryer type.  Design a small machine and include some components that can make it easier to move.

Learning Outcome Actions  What kind of weight  Brainstorming sensor is suitable for  Gather information this application. from sources.  What type of (internet, heating element literature, etc) should be used other than solar dryer.  What type of components that can increase the mobility of the chamber and solar collector. (adjust the angle, pulling from one place to the other, etc)

b) Triz Method Triz method has been used to generate idea for improving the machine to be better one. All of the designs to follow all of the specifications guided by the TRIZ method. By observing and discussing all of the advantages and limitations for each of the designs, a suitable final design can be decided. Triz matrix contradiction and the complete steps in deciding the ideas by using Triz method are included in Appendix B.

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Statement 1: During rainy season, the dryer must be able to continue drying of pepper berries when the solar radiation is unavailable. Step 1 – Identify the contradictions Improving feature: Versatility Preserve feature: Reliability Step 2 - Look at the list of features and identify those important to your contradiction (Appendix). Versatility 35 Reliability 27 Step 3 - Identify the improving and worsening features from triz matrix above and brainstorming It is found that the features intersect at fourth row and first column. The Altshuller’s Principles involved are: 35. Parameter Changes: Change the temperature For the dryer to continue drying the pepper berries even in raining season, we need to ensure the temperature is always appropriate to used. 8. Anti – Weight The weight of the dryer can be compensated by adapting the shape of dryer to environment. By adding new way to drying the pepper it not be the constraint on the dryer weight. Conclusion: By using solar dryer it can help to continue drying the pepper berries even in raining. Besides, it should be able to continue drying until late evenings to shorten the drying period. Statement 2: The machine should be cost effective since pepper is a small business. Designing a reasonable price machine ensure farmer can afford to buy it. At the same time, the designed machine must have productivity higher than traditional way of drying, typically open air sun drying. Step 1: Identify the contradictions Improving feature: Productivity Worsening Feature: Device Complexity Step 2: Look at the list of features and identify those important to your contradiction. 20

Productivity

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Device Complexity 36 Step 3 Identify the improving and worsening features from Triz matrix above and brainstorming It is found that the features intersect at eighth row and column. The Altshuller’s Principles involved are 12. Equipotentiality: Triz40 proposed equipotentiality, which encourage the object to remain in a fix position. This can eliminate the usage of material transport equipment, which enable simpler design of machine, thus reducing cost of processing. 17. Another Dimension: Triz40 proposed the use of a multi-storey arrangement of objects instead of a single storey arrangement. This solution can be implemented to the arrangement of pepper berries in machine to promote higher productivity. Instead of drying the pepper berries in a traditional way by spreading on a platform, the machine can be designed to accommodate multi-storey of pepper berries, which enable drying of several trays of pepper berries at the same time. Besides, one can fix heating element to the sides of machine rather than fixing it at the bottom of the machine as this will lead to uneven rate of drying. 28. Mechanics Substitution: The device complexity can be reduced by replacing complicated sensory system to simpler one. For example, we can measure the time required for the pepper berries completely dried under the operating temperature of the designed machine. Then, a timer is fixed to the machine as alarming device after each batch of drying process is done. 24. Intermediary: Triz40 suggest the use of intermediary carrier to reduce device complexity. This solution can be used by implementing human workforce to do loading and unloading instead of using equipment such as conveyor belt and feeder. This reduce the overall size of machine, thus reducing complexity. In conclusion, to increase productivity while reducing the complexity of device, one can design multi-storey dryer with heating element felt at sides. Furthermore, use timer instead of complex sensory system to reduce cost. Lastly, avoid application of conveyor belt and feeder to reduce size of machine.

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c) Ideas Selection Based on the Triz matrix that have been done, the most crucial part in the designing the dryer machine its heating element, pepper container and berries arrangement. The drying rate of the pepper berries depends on the factors that involved. Concept Sketches by member groups are included in Appendix C.

Heating elements Hereby, there are few types of heating element that can be take account to be consider in designing the dryer machine. a. Direct sunlight: Direct sunlight give exposure to the berries to be dehydrated. This kind of drying method expose to higher bacterial contamination and lower the quality of the pepper berries. b. Solar dryer: Its conventional method to dry the black pepper. For this method, it is an indirect solar drying by which the atmospheric air is heated in flat plate collector or solar absorber that usually painted in black colour. c. Hot air blower: Electrical energy is the power source of this method. It uses the conversion of electrical energy to heat energy. Heating element produces heat and this heat is used to dry the black pepper. d. Heat exchanger (water heater): From the electrical energy it heat up the water and produce hot air. The hot air from the water heater it being used to dry the black pepper. Pepper Container and the Arrangement The pepper is chosen to be stacked up on top of each other like multiple storey housing to limit the space consumption when compared to the direct sunlight method. The pepper container is made up of stainless steel wire mesh because it can resist corrosion and comply food standard without contaminate the food. Also, stainless steel is metal that very good in thermal conduction with low specific heat capacity. The metal can be easily absorb heat from the surrounding and dry up the pepper using thermal heat conduction method.

22

Ventilation For the ventilation system, we need to deliver certain amount of air supply to the pepper dryer. This ventilation process is to supply the air inside the chamber as well as controlling the temperature inside it. If the temperature already exceed the limit, the air will be blow inside to make sure the quality of the pepper is maintained. For this project, we will using ventilation system to blow the air inside. Therefore, mechanical ventilation method is the best method to be use. The ventilation system will be including the fan or blower to supply the air and some pipeline or air duct for air flow.

Insulation Without insulation, the heat will be loss easily from the surface of the dryer and the heat is carried away by convection through the air. However, the insulation should not affect the direct sunlight from enter the dryer so that it will receive maximum intensity of light. Considering the problem of direct sunlight, the insulation must be translucent and one of the way to achieve this design is construct an air gap at the wall of the dryer. The air gap provide a good insulation to trap the heat from being carried away by the moving air. In the meantime, this type of insulation is translucent which is not blocking any sunlight from entering the dryer.

3.4.3 Morphological Chart Table 3.2: Morphological Table for the Features in Drying Chamber Features

Option 1

Option 2

Option 3

Heating Element

Solar Collector

Hot Air Blower

Heat Exchanger

Type of Dryer

Rotary dryer

Tray dryer

Conveyor dryer

23

Table 3.3: Comparison between the Type of Heating Element Type of Heating Element Solar Collector Hot Air

Criteria

Blower Power

Not used power

consumption

consumption

Environmentally

Heat Exchanger

High

Moderate

Moderate

High

High

Efficiency

Moderate

Moderate

High

Rate of drying

Low

High

Moderate

Cost

Low

High

Moderate

friendly

Table 3.4: Comparison between the Type of Dryer Type of dryer

Criteria

Rotary Dryer

Tray Dryer

Conveyor Dryer

Power

High

consumption

Not

used High

power consumption

Maintenance

High

Low

High

Efficiency

Moderate

Moderate

High

Rate of drying

High

Moderate

Moderate

High

Moderate

Low

High

Surface

contact Moderate

in drying Cost

High

Based on the morphological chart above, Solar drying method is a conventional method that is used to dry black pepper. It uses renewable energy which is sun as the power source and promotes environmental friendly. Differs from direct solar drying, this method offers better quality of drying product and thus, this method meets specifications on standard product quality. Besides, it can reduce the drying time when compared to direct solar drying method due to the aids of flat plate collector or solar absorber. Solar drying method is the most cost effective compared to the other drying 24

methods. Solar drying method is not working in case of rainy weather. Therefore, heat exchanger method is an alternative method for pepper drying. As the hot air blower is expensive and the power consumption high, thus, with replace the hot air blower to the heat exchanger it might can be used, since the temperature air from the heat exchanger can be control and not that high so the quality of the pepper berries can be preserved. While, for the type of dryer, tray has been chosen to be used in our project. Since it has good criteria as just shown in the figure.

3.5 Concept Evaluation 3.5.1 Pugh Selection Method Table 3.5: Selection of Dryer Type Type of Dryer Criteria High Efficiency Low Maintenance Low Cost Uniform Heat Distribution Large Surface Contact in drying

Importance Weight 0.2 0.2 0.2 0.2

Rotary Dryer Rating Weighted Rating 3 0.6 2 0.4 2 0.4 3 0.6

Alternatives Tray Dryer Rating Weighted Rating 3 0.6 4 0.8 3 0.6 2 0.4

Conveyor Dryer Rating Weighted Rating 4 0.8 2 0.4 2 0.4 3 0.6

0.2

3

4

0.8

3

0.6

3.2

Total

2.8

0.6

Total 2.6 Total Based on the table 3.5, tray dryer is selected as our design

Table 3.6: Selection of Heating Element Heating Element Criteria Low Electric Consumption Environmental Friendly Efficiency Availability Drying Rate

Importance Weight 0.2

Solar Collector Rating Weighted Rating 4 0.8

Alternatives Heat Exchanger Rating Weighted Rating 3 0.6

0.2

4

0.8

3

0.8

2

0.4

0.2 0.2 0.2

3 2 2 Total

0.6 0.4 0.4 3.0

3 4 3 Total

0.6 0.4 0.8 3.2

3 4 3 Total

0.6 0.8 0.6 2.8

Hot Air Blower Rating Weighted Rating 2 0.4

Based on the Table 3.6, the heat exchanger is the best heating element. In selected design, a hybrid dryer of heat exchanger and solar power is the main approach of the design considering environment and sustainability of energy resources. 25

3.6 Embodiment Design 3.6.1 Product Architecture Product architecture is the arrangement of the physical elements of a product to carry out its required functions. The physical building blocks that the product is organized into are usually called modules. Each module is made up of a collection of components that carry out function. In this section, a four-step process for establishing the product has been made, which there are consists of schematic diagram of product, cluster the elements of the schematic, a rough geometric layout and the interaction between modules. The design of drying machine is based on modular architecture. This is because each module, such as drying chamber, material supply, solar collector and electrical water heater carry out their respective functions. The type of modular that has been used is slot modular architecture, which in each of module to module interface is different from the others. Module cannot be swapped around. Each interface between the modules in a slot modular is of the different type from others, so that the various modules in the product cannot be interchange.

Figure 3.2: Schematic Diagram of Pepper Dryer

26

a) Create Schematic Diagram of The Product The decomposition of the pepper dryer is according to the function of each of the component in the machine. Figure 3.2 shows that the solar collector is used to heat up the air inside the drying chamber and electrical operated water heater is used as an alternative to supply heat to the drying air during rainy season. Ac supply is responsible in providing electric energy to the exhaust fan and heating element of water heater. The exhaust fan is use to exhaust the air out. On the other hand, drying chamber is for is for isolating the pepper berries from the outside environment during drying process. After each batch of drying is done the dried pepper berries will be removed and a new batch of fresh pepper berries will be supplied back.

Figure 3.3: Grouping Design Elements into Modules b) Cluster the elements of the schematic Each component involved in the machine is grouped into modules according to their similarity of function. AC supply and fan involve the conversion of energy which from electrical energy and supply to the fan so that fan can exhaust air out. Drying chamber, together with the delivery of unprocessed pepper berries will act as the process chamber to ensure the particles are dried at the end of each session. Solar collector and electrical water heater work as heating element which supply heat then 27

travel into the drying chamber. The last module act as material supply. It is the reservoir of raw material which ensure the continuous supply of material to be process without interruption.

Figure 3.4: Energy flow on the Schematic Diagram

28

c) Identify the interaction between modules According to Dieter and Schmidt (2009), interactions between neighbouring modules can be classified into four types, namely spatial, energy, information and material. i.

Spatial interaction There are several physical interfaces involved. The collector is connected to drying chamber using flexible dryer vent whereas flexible copper tube is used to connect solar collector and water heater, then from water heater to drying chamber. Electrical cable is used to connect power supply to ventilation fan and heating element of water heater.

ii.

Energy flow Solar radiation is collected and stored in solar collector as heat. For solar collector, ambient air is flow into the collector and heat up. Ventilation is maintained by the fan fixed at top of drying chamber, thus enabling the hot air from solar collector flow in a forced convection manner from bottom to the top of chamber. The drying machine is designed based on hybrid concept. The temperature of drying chamber is maintained with the help of electrical resistance heating. When solar collector cannot supply the required temperature for drying, the air is further heated up by water heater. In water heater, electrical energy is supplied to the resistance heating element. Electrical energy is converted to heat energy, which transfer via water, heat from water is absorbed by flowing air in the flexible copper tube, thus heat up the air. On the other hand, electrical energy is converted to rotational energy of motor, turning the fan to maintain a constant ventilation system.

iii.

Information flow The machine is designed for batch production whereby the time for each batch of pepper berries to be dried completely may take up to 24 hours. The temperature and pressure are constantly measured by the thermostat and pressure gauge. Proper manual adjustment is required to maintain an optimum condition for drying process.

29

iv.

Material flow Fresh pepper berries is fed into the drying chamber at the beginning of the process. When the operation starts, moisture from the berries is extracted by the moisture separator and drained out of the machine.

3.6.2 Configuration Design

Figure 3.5: The Overall Design of the E-Z Dryer. 800mm

1200mm

In this section, a general dimension of the dryer have been proposed as a guideline to further design analysis. Figure 3.5 shows the overall design of the E-Z Dryer. In this section, arrangement of the whole dryer component and materials selected as a part of the drying chamber is discussed.

30

3.6.2.1 Arrangement and Design Tray Arrangement:

Figure 3.6: Options for the Tray Arrangement The tray arrangement is designed based on the ergonomic factor of the farmer. To ease the operation, the design should not be too high or be too low. Option 1 is selected as the tray can be divided to two chamber to avoid the tray from stacking too high as option 2. Tray Design:

Figure 3.7: Options for the Tray Design Option 1 is selected as the wire mesh allows more surface area of pepper that exposed to the air and increase the drying rate. Option 2 covers the bottom surface of the pepper totally. Wire mesh have good dewatering and separation characteristics in application of wire mesh belt. In tray design, this characteristics could be referred. 31

Support Stand:

Figure 3.8: Options for Support Stand The support stand is should be able to support the drying chamber from falling or tumbling. Option one support the dryer chamber at both left and right. Option 2 only support the middle part of the drying chamber which make it unstable. 3.6.2.2 Standard Parts and Special Design Parts The component or parts in this design is divided into standard parts and special design part. The special design parts is stated as follow: 

Solar collector



Water boiler



Drying chamber



Connection pipeline

The special design parts is constructed from standards part available in the market. They all have been listed in Table 3.7

32

Solar collector Table 3.7: Standard Parts used for solar collector Materials

Reasons

Acrylic (Solar collector cover)

Acrylic vs Polycarbonate 

Lighter, cheaper, better emissivity, same thermal conductivity, strong enough for this application.



Copper plate (Solar absorber)

Highest thermal conductivity (2x than Al) compared to other typical heat absorbing materials, easy to handle for fabrication, available in local market.

Styrofoam (Insulation)

Styrofoam vs Fiberglass 

Light, cheap, easier to handle, safer to handle, higher thermal resistance value, better weather resistor.



Local wood (Frame)

Cheap, widely available, strong enough for this application

Wire mesh (Air inlet)



To prevent any entering of obvious contaminants or bugs into the product.

Water boiler Table 3.8: Standard parts used for water boiler Materials Stainless steel 316 (Tank structure)

Copper coil (Water heating element)

Reason 

High yield and tensile strength



Has good corrosion resistance



Good conductor of heat thus results in loss of heat (release heat to heat up the water in the water tank).

Styrofoam (Insulation)



Light, cheap, easy to handle, high thermal resistance value.

33

Drying chamber Table 3.9: Standard parts used for drying chamber Material

Reasons 

Aluminium 3003 Alloy (Trays frame) Aluminium 3003 Alloy (Trays)

Good heat conductivity for food drying application and lighter than steel.



Aluminium 6060 (Trays support) Aluminium 6060 Alloy (Trays support)

Good durability to support force from berries and trays.

Polycarbonate Sheet



Good heat insulation and strong



Light, cheap, easy to handle, high thermal

(Insulation and chamber cover) Styrofoam (Insulation)

conductivity 

ASTM A36 (Frame support)

High ultimate strength to support force from upper section of drying chamber.

Caster wheel (2 swivel, 2 break)



Mobility

Door hinge



Loading and unloading process



To determine the weight loss from early and end

Door latch Simple door handle Load Cell

process. Thermocouple



Determine temperature

PLC



Control the temperature of water boiler

Pipeline Connection Table 3.10: Standard parts used for pipeline connection Material

Aluminium pipe

Tubular pipe insulator

Reason



Higher melting point compared to PVC



Low thermal expansion



Very good corrosion resistance



Light, cheap, easier to handle, good insulator



Suitable for pipe-shaped

34

3.7 Parametric Design (Design Analysis) 3.7.1 Mechanical Analysis 3.7.1.1 The Capacity of Fresh Berries The capacity of fresh berries in a tray can be determined by finding the total volume of fresh berries inside the trays aided with the dimension of the tray. According to Akinoso et. al. (2013), the size of a fresh berry is 5 mm with the density of 590 kg/m3. From here, the mass of a fresh berry can be determined. Hence, the total capacity of fresh berries can be determined. Figure 3.6 shows the diagram of a tray with its dimension. Total volume covered by fresh berries in a tray is 6.546x10-8m3. From this point, the mass of fresh berries per tray is 1.71 kg. As 24 trays are designed, hence, the total capacity of fresh berries per drying batch is 41 kg. Refer to Appendix F and I for detailed analysis.

750mm 10mm 750mm Figure 3.9: Diagram of a tray with its dimension

3.7.1.2 Bending Analysis The structures in this design can be approximated as a straight beam or as a collection of straight beams. In this design, there are three parts or structures that need to be analysed in terms of their bending analysis. The parts are tray, tray holder and support stand of drying chamber. In order to find the value of maximum deflection, y max, second polar moment of area, I, of the relative parts have to be considered. There are two types of properties of structures in this design which are square and equal legs angles. Table 3.11 shows the

35

diagrams and equations of the properties of structures. This section covers the maximum deflection, shear force and bending moment that are aided with diagrams. Table 3.12 below shows the diagrams and equations of the bending analysis of parts. Table 3.11: Diagrams and equations of the properties of structures (Budynas & Nisbett, 2015) Properties of structure Square

Equation second polar moment of Inertia, I =

a

Unit = m4 a = Length of square (m)

a

x

b

x

Equal legs angles c

(Equation 3.1)

bh3 second polar moment of Inertia, I = 12 Unit = m4 a = Length of square (m)

Rectangle

h

a4 12

(Equation 3.2)

second polar moment of inertia, I 1 = ( ) (t(c 3 ) + a((a − c)3 ) 3 − (a − t)((a − c − t)3 ))

(Equation 3.3)

Unit = m4 a = width of equal legs angles (m) t = thickness of equal legs angles (m) c = distance of axis to extreme fiber (m) (a2 ) + at − t 2 c=a− 2(2a − t)

(Equation 3.4)

36

Table 3.12: Diagrams of and equations of the bending analysis of parts (Budynass & Nisbett, 2015) Part Maximum deflection

Equation 4 −5wl Deflection, y = max 384EI Unit = m w = weight per meter (N/m) l = length of beam (m) E = modulus of elasticity (Pa) I = second polar moment of area (m4)

(Equation 3.5)

Shear force Shear Force, V = (

wl ) − wx 2

Unit = m w = weight per meter (N/m) l = length of beam (m) x = distance of analysed bending of beam

(Equation 3.6)

Bending moment

wl Moment of Inertia, M = ( )(l − x) 2 Unit = Nm w = weight per meter (N/m) l = length of beam (m) x = distance of analysed bending of beam

(Equation 3.7)

By using equations in Table 3.11 and Table 3.12, the bending analysis for tray, tray holder and support stand are determined. Table 3.13 shows the summarised bending analysis results. Table 3.13 Summarised Bending Analysis Results Part

Section (Colour)

Tray

Orange

Tray Holder

Blue

Property of structure Square

Equal legs angles

Bending analysis at L/2 Maximum deflection = -5.074x10-11m Shear Stress =0N Moment of Inertia = 1.598 Nm Maximum deflection = -0.0064 m Shear Stress =0N Moment of Inertia 37

Support Stand

Red

Rectangle

Blue

Equal legs angles

Red

Equal legs angles

= 5.649 Nm Maximum deflection = -4.669x10-5 m Shear Stress =0N Moment of Inertia = 12.371 Nm Maximum deflection = -0.047 m Shear Stress =0N Moment of Inertia = 269.591 Nm Maximum deflection = -0.0062 m Shear Stress =0N Moment of Inertia = 136.904 Nm

From Table 3.13, the negative sign of maximum deflection means that the beams deflect downward. For zero value of shear stress, it means that the shear stresses in the middle of the beams are zero due to equal distribution of forces. The results also show that the only small deflections occur for all of the parts. Hence, all of the parts are safe design. Refer to Appendix D, E, F and G for product catalogues and Appendix G J for detailed analysis. Theoretical calculation estimate and simulation estimate: Component Support Stand Tray Tray Holder

Theoretical Deflection, mm 6.2 5.074 x 10-8 6.4

Simulation Deflection, mm 7.865 0.05242 0.2854

Design Consideration 6.2 mm 0.05242 mm 6.4 mm

Note that the large difference between theoretical calculation and simulation estimate of deflection and a larger value of deflection is always taken into account in design analysis. In manual calculation, assumption has been made on the loading. For example, a bending of an angle bar is always assumed to have a highest deflection in the middle. But Solidworks simulation shown the maximum deflection might occur somewhere else. So, this explain the weakness of manual calculation and the helpfulness of simulation software in design. Please refer to Appendix J for the calculation and simulation analysis.

38

3.7.1.3 Buckling Analysis According to Hibbeler (2013), buckling may occur when a structure is experiencing a compressive stress. Buckling is defined as a sideway deflection of a structural member at which can lead to failure. In this buckling analysis, columns of the support stand are to be analysed by using Equation 3.8 and Equation 3.9 as they are the critical point of buckling. Π2 EI

Critical Loading, Pcr = (KL)2

(Equation 3.8)

Unit = N E = modulus of elasticity (Pa) I = least moment of inertia for the column’s cross sectional area (m4) K = effective-length factor L = unsupported length of the column (m) Pcr

Allowable Force, Fa = F.O.S

(Equation 3.9)

Unit = N Pcr = critical loading (N) F.O.S = factor of safety From Equation 3.8, the critical loading, Pcr when designed with equal legs angles of ASTM A36, is 389213.31 N. With factor of safety and effective-length factor of 1.5 and 0.5 respectively, the allowable force is 259475.54 N when calculated by using Equation 3.9. As the force of 1297.67 N (force from drying chamber when fully loaded with fresh berries) reacts on of support stand, P, the column will not buckle since the force is lower than the allowable force. Hence, it is a safe design. Figure 3.6shows the column of support stand. Refer to Appendix K for detailed analysis.

P

Figure3.10: Column of support stand 39

3.7.1.4 Joining Analysis Joining analysis is significant in order to determine whether the fastener will fail or otherwise at certain amount of shear stress. In this design, rivets, bolts and nuts are being used as fasteners. Welding is also being used as permanent joining method between structural members of support stand. However, rivets and welding are neglected in this joining analysis. This is because the rivets are only used on certain parts that do not exert much force and approximately negligible. Meanwhile, welding is depending on the skill by the fabricator itself and thus, joining analysis for welding is neglected. Only bolts and nuts are analysed in this design and can be determined by using Equation 3.10 and Equation 3.11. Shear Stress, T =

FB

(Equation 3.10)

A

Unit = Pa FB = Force on bolts (N) A = Cross sectional area of bolts (m2) Allowable Stress, σa =

Yield Strength

(Equation 3.11)

F.O.S

Unit = Pa Yield strength = yield strength of material F.O.S = factor of safety Force acted on one of the bolt is 1297.67 N. As 5 mm of diameter of bolts are chosen in this design, the shear stress acts on the bolt is 66081423.3 Pa when calculated by using Equation 3.10. As the shear stress is less than allowable stress which is 143333333.3 Pa, the bolt will not fail. Figure 3.11 shows the top face of support stand. Refer to Appendix H and Appendix L for product catalogue and detailed analysis, respectively.

FB bolt

Figure3.11: Top face of support stand

40

3.7.1.5 Ergonomic Analysis Based on standard ergonomic design, primary arm and shoulder muscles (arm fully extended), horizontal pushing and pulling forces must not exceed 110 N (Wiley, 2004). In this design, forces for pushing or pulling drying chamber door and whole drying chamber are analysis. In order to push or pull the aforementioned parts, the minimum forces required must be able to resist the friction forces at which can be calculated by using Equation 3.12. Friction force, Fr = μR

(Equation 3.12)

Unit = N 𝜇 = coefficient of friction R = Reaction force acted on the parts Minimum force required to push or pull the drying chamber is 44.18 N. Hence, the design is ergonomic as it is complying standard ergonomic design which is the pulling or pushing force when arm fully extended is must less than 110 N. For pushing or pulling the drying chamber door, ones can simply pushes or pull the door as the force exerted on it is much lower than the reaction force on the caster wheel (mechanism for the mobility of drying chamber). Refer to Appendix M for detailed analysis.

Validation of this project can be refer to Appendix Q

41

3.7.2 Thermo – fluid Analysis Analysis of Mass Flow Rate of Air and Moisture Removal Rate using Solar Collector. Type of solar collector: Flat Plate. Heat absorbed by solar collector, ̇ 𝐚𝐛𝐬 = 𝛕𝛂𝐀𝐆 𝐐

(Equation 3.13)

The governing equations are adapted from Cengel A.C. and Michael A.B. (2015): τ=transmissivity of glazing α=absorptivity of absorber plate A=area of collector surface G=solar insolation or irradiation Heat loss from the solar collector, 𝐐̇𝐥𝐨𝐬𝐬 =

∆𝐓 𝐑

(Equation 3.14)

∆𝑇 =temperature difference R =thermal resistance of material Useful heat energy to be transfer to the drying chamber, 𝐐̇𝐮𝐬𝐞𝐟𝐮𝐥 = 𝐦̇𝐜𝐩 (𝐓𝐨𝐮𝐭 − 𝐓𝐢𝐧 ) = 𝐐̇𝐚𝐛𝐬 − 𝐐̇𝐥𝐨𝐬𝐬

(Equation 3.15)

𝑚̇=mass flow rate of air inside the collector Cp=specific heat capacity of air Tout=outlet temperature of air Tin=inlet temperature of air

42

Efficiency, ƞ=

𝐐̇𝐮𝐬𝐞𝐟𝐮𝐥 𝐐̇𝐢𝐧𝐜𝐢𝐝𝐞𝐧𝐭

(Equation 3.16)

Where, 𝐐̇𝐢𝐧𝐜𝐢𝐝𝐞𝐧𝐭 = 𝐀𝐆

(Equation 3.17)

A= Area of solar collector G= Solar irradiation Analysis: The analysis is restricted to the solar insolation or irradiation in Kuching, Sarawak. The table below shows the solar insolation from July to September in daily average. Month

Solar Irradiation (kWh/m2)

July

4.80

August

4.55

September

4.16

October

4.13

Source: Sarawak Energy, 2013. July to October is the harvesting month of a pepper in a year. The value of solar irradiation from September is taken to do the analysis because it is the lowest among the four of the values. From Sarawak Energy, the average solar irradiation per day in Kuching is 4 hours. Hence, solar irradiation, 𝐺=

4.16𝑘𝑊ℎ/𝑚2 4ℎ

𝐺 = 1.04𝑘𝑊/𝑚2 43

The area of solar collector exposed to the sunlight is, 𝐴 = 1 × 1.5 𝐴 = 1.5𝑚2 Using Equation 3.13, heat absorbed by the collector is found: 𝑸̇𝒂𝒃𝒔 = 𝝉𝜶𝑨𝑮 𝜏acrylic = transmissivity value of acrylic = 0.92 (Source: INDUFLEX, Acrylic Processing) 𝛼copper plate = absorptivity value of black painted copper plate = 0.97 (Source: Solarmirror, Absorptivity and Emissivity) 𝑄̇𝑎𝑏𝑠 = 0.92(0.97)(1.04) 𝑄̇𝑎𝑏𝑠 = 0.928𝑘𝑊 Also, the ambient air is assumed to be Ta = 25°C, and the ideal collector should be able to reach Tc = 40°C. By using Equation 2, heat loss from the collector through conduction is determined: 𝑸̇𝒍𝒐𝒔𝒔 =

∆𝑻 𝑹

The R value can be obtained by calculating the thermal resistance for all of the interior surfaces of solar collector.

44

1m 1.5m 0.3m

The interior surface of the solar collector consist of 2 different sheets as the frame which are, Styrofoam as the insulator and wood as the outer frame. The thickness of the styrofoam sheet is 2cm, whereas the wood is 3cm, the areas are given below, the temperature difference is 15°C. ks, Styrofoam thermal conductivity = 0.033W/m.K(Source : Hyperphysics, Thermal Conductivity) kw, Local wood thermal conductivity = 0.16W/m.K(Source : S. Zhua et al., 2003) For Area = 1 * 0.3 = 0.3m2, 𝑅=

𝑅=

𝑙𝑤 𝑙𝑠 + 𝑘𝑤 𝐴 𝑘𝑠 𝐴

0.03 0.02 + (0.16)(0.3) (0.033)(0.3) 𝑅 = 2.645

As the solar collector consists of 2 same interior surfaces with same dimension, except for the acrylic surface, R*2 = 5.29

45

For A = 1.5 * 0.3 = 0.45m2, R*2 = 3.527 For A = 1.5*1= 1.5m2 R = 0.525 For Aacrylic = 1.5*1 = 1.5m2 Racrylic = 3.51(10-3) Summation of R, ΣR = 5.29 + 3.527 + 0.525 + 3.51(10-3) = 9.346 By having the total thermal resistance of the internal solar collector surfaces, we can use Equation 3.14 now. 𝑸̇𝒍𝒐𝒔𝒔 =

∆𝑻 𝑹

̇ = 15 𝑄̇𝑙𝑜𝑠𝑠 9.346 ̇ = 1.6𝑊 𝑄̇𝑙𝑜𝑠𝑠 Next, the useful energy collected in the solar collector is determined using Equation 3.15: 𝑸̇𝒖𝒔𝒆𝒇𝒖𝒍 = 𝑸̇𝒂𝒃𝒔 − 𝑸̇𝒍𝒐𝒔𝒔 𝑄̇𝑢𝑠𝑒𝑓𝑢𝑙 = 0.928𝑘𝑊 − 0.0016𝑘𝑊 𝑄̇𝑢𝑠𝑒𝑓𝑢𝑙 = 0.9264𝑘𝑊 The efficiency of the solar collector could be estimated from Equation 3.16: 𝑸̇𝒖𝒔𝒆𝒇𝒖𝒍 ƞ= 𝑸̇𝒊𝒏𝒄𝒊𝒅𝒆𝒏𝒕 ƞ=

0.9264 𝐴𝐺 46

ƞ=

ƞ=

0.9264 1.5 (1.04)

0.9264 = 0.6 = 60% 1.5 (1.04)

The Moisture and Water Removal Rate of the pepper berries. Given the mass of pepper per operation is 20 kg. The moisture content of fresh berries is 77%. Hence, the mass of moisture inside the fresh berries is, 𝑚𝑤𝑖 = 0.77 × 25 𝑚𝑤𝑖 = 19.25 𝑘𝑔 Dry solid mass of pepper is, 𝑚𝑑 = 25 − 19.25 𝑚𝑑 = 5.75 𝑘𝑔 During the drying process, the dry mass of pepper is conserved and only water is evaporated from fresh berries. So the dry mass in the dried berries is constant and only mass of moisture is decreased. After drying process, the moisture content of the pepper is decreased into 12%. So the total mass of the pepper after drying process could be found as follow: 5.75 = (1 − 0.12) × 𝑚𝑓 𝑚𝑓 = 6.53𝑘𝑔 The moisture content in dried pepper: 𝑚𝑤𝑓 = 6.53 − 5.75 𝑚𝑤𝑓 = 0.78 𝑘𝑔

47

The total moisture removed: 𝑚𝑤 = 𝑚𝑤𝑖 − 𝑚𝑤𝑓 𝑚𝑤 = 19.25 − 0.78 𝑚𝑤 = 18.47 𝑘𝑔 Heat loss due to conduction: The interior surfaces of the drying chamber consist of two different materials which are Styrofoam as the insulation and polycarbonate as the outer frame. Assume the thickness of the polycarbonate sheet to be 1cm, thickness of Styrofoam is 2cm, the area is given below, the temperature difference is 15°C and the thermal conductivity of the polycarbonate is 0.22 W/m.K, Styrofoam 0.033W/mK. The calculation of R value is needed to find out the heat loss through conduction: The dimension for the interior space of the drying chamber: 1.65m 0.85m

0.76m

Thus, we have 6 surfaces for the calculation: For Area = 1.65 * 0.85 = 1.4m2, 𝑅=

𝑅=

𝑙𝑝 𝑙𝑠 + 𝑘𝑝 𝐴 𝑘𝑠 𝐴

0.01 0.02 + (0.22)(1.4) (0.033)(1.4) 𝑅 = 0.466

48

As the drying chamber consists of 2 same surfaces with same dimension, R*2 = 0.932 For A = 1.65 * 0.76 = 1.254m2 R*2 = 1.039 For A = 0.76 * 0.85 = 0.646m2 R*2 = 2.016 Summation of R, ΣR = 0.932 + 1.039 + 2.016 ΣR = 3.987 Heat loss, 𝑄̇ =

∆𝑇 𝑅

𝑄̇ =

15 3.987

𝑄̇ =

15 3.987

𝑄̇ = 3.762𝑊 Thus, the rate of heat that can be trapped in the drying chamber: 𝑄̇𝑛𝑒𝑡 = 𝑄̇𝑢𝑠𝑒𝑓𝑢𝑙 − 𝑄̇ The 𝑄̇𝑛𝑒𝑡 can be obtain from the rate of heat transferred from the solar collector ̇ 𝑄̇𝑛𝑒𝑡 = 0.9264𝑘𝑊 − 3.762𝑊 𝑄̇𝑛𝑒𝑡 = 0.9226𝑘𝑊 The removal rate of water could be found by: 𝑸̇𝒏𝒆𝒕 = 𝒎̇𝑳

49

The L is the latent heat of vaporization for water

Source : JEE Mains and JEE Advanced Online Coaching for NRIs Students, on Fluids Latent Heat of Evaporation

𝑚̇ =

𝑚̇ =

𝑄̇𝑛𝑒𝑡 𝐿

0.9226𝑘𝑊 2257𝑘𝐽/𝑘𝑔

𝑚̇ = 4.088(10−4 )kg/s As we know, 𝑚̇ = 𝑚/𝑡 𝑡 = 𝑚/𝑚̇ 𝑡=

18.47𝑘𝑔 4.088(10−4 )𝑘𝑔/𝑠 𝑡 = 44492 𝑠 𝒕 = 𝟏𝟐 𝒉𝒐𝒖𝒓𝒔

Thus, the time taken for the whole process of berries drying is expected to be in 12 hours Calculate air volume flow rate to remove 18.47kg of water in 12hours.

50

Determination of dry bulb temperature and wet bulb temperature In order to find the dry and wet bulb temperature, experiment have been done. The procedures of the experiment is included in Appendix N.

Figure 3.12: Setup of experiment (a) Control condition (b) Dry bulb temperature (left) and wet bulb temperature (right) Set 1

Set 2

Set 3 Average

Dry Bulb Temperature (℃)

27

27

27

27

Wet Bulb Temperature (℃)

24

24

24

24

The humidity of air is obtained from the psychrometric chart (Appendix O) by interpolation based on the dry bulb and wet bulb temperatures obtained from the experiment. Initial condition: Dry bulb temperature: 27 Wet bulb temperature: 24

51

From Psychrometric chart: RH

82.0%

Absolute Humidity

0.01849kg/kg of air

Dew Point

23.7

Enthalpy

74.3kJ/kg

Specific volume

0.88m^3/kg

Heating: Air is heated to 40 degree Celsius Dry bulb temperature: 40 Abs Humidity: 0.01849kg/kg of air The absolute humidity of the air remain unchanged because there is no moisture added during the process of heating (Earle, 2004). From Psychrometric chart: RH

39.6%

Wet bulb temperature

27.1

Dew Point

23.7

Enthalpy

87.8kJ/kg

Specific volume

0.91m^3/kg

The temperature of air leaving the drying chamber should be in the range of above dew point temperature and below the dry bulb temperature. Hence, taking the average temperature of dew point and dry bulb temperature as the temperature of air leaving the drying chamber. Dry bulb temperature leaving drying chamber =

40+23.7 2

= 31.85 In the context of air, humidification process (Earle, 2004) occurred in the drying chamber. Evaporation causes enthalpy of moisture absorbed to convert liquid to vapour. Hence, wet bulb temperature remains unchanged in the drying chamber. 52

RH

73.4%

Absolute Humidity

0.02201kg/kg of air

Dew Point

26.5

Enthalpy

88.3kJ/kg

Specific volume

0.89m^3/kg

Calculate the amount of water removed by passage of 1kg of air: Initial moisture content of air at 40 degree Celsius: 0.01317kg/kg of air Final moisture content of air leaving the drying chamber: 0.02201kg/kg of air Moisture removed by 1kg of air = 0.02201 – 0.01317 = 8.84x10^-3 kg Total water needed to be removed in each batch of pepper berries: = 18.47kg Mass of air needed to remove 14.77kg of water: 14.77/8.84x10^-3 = 2089.37 kg Mass flow rate = 2089.37kg/44492s = 0.047kg/s Calculate volume of air passing through the chamber: Specific volume of air at 40 degree Celsius: 0.91m^3/kg Volume of air = 0.91 x 1670.81 = 1520.44m^3 Time needed for each drying process: 44492s Volume flow rate = 1520.44/44492 = 0.034m^3/s

53

Properties of air at 1atm and bulk mean temperature of 40+20/2 = 30 ˚C. Refer from Table A-15 Properties of air at atmospheric pressure (Appendix P). Diameter of pipe, D = 0.097m 𝑚̇ = 0.047𝑘𝑔/𝑠 𝑚̇

𝑉𝑚 = 𝜌𝐴 0.047

= 1.164×𝜋×0.04852 = 5.46 m/s Re =

𝑉𝑚 𝐷 𝑣 5.46 𝑥 0.097

= 1.608𝑥10−5

= 32,937 > 10,000 (Turbulent flow) Assume fully developed turbulent flow: Nu =

ℎ𝐷 𝑘

= 0.023𝑅𝑒 0.8 𝑃𝑟 0.3

= 0.023(32,937)0.8 (0.7282)0.3 = 86.01 h=

𝑁𝑢 𝑘 𝐷

=

86.01 𝑥 0.02588 0.097

= 22.95 w/m^2 C

54

Since the temperature of the air varies along the pipe as heat is continuously gained from the water. Hence, log mean temperature difference is computed to indicate the average temperature difference between two fluids. The negative sign indicates the heat transfer gradient which decrease with distance (Cengel, 2003). Logarithmic mean temperature difference: 𝑇𝑠 − 𝑇𝑖

∆𝑇𝑙𝑛 =

𝑇 −𝑇 ln( 𝑠 𝑒 ) 𝑇𝑠 − 𝑇𝑖

=

40−20 90−40 ) 90−20

ln(

= -59.44 𝐴𝑠 = 𝜋𝐷𝐿 = 𝜋 (0.097)𝐿 Rate of heat absorbed by the copper tube from water 𝑄̇ = h𝐴𝑠 ∆𝑇𝑙𝑛 , = 22.95x 𝜋 (0.097)𝐿 x 59.44 = 416L

The power of water is supplied by electrical heating element rated 1500W. The heat loss to surrounding due to convection and conduction through the water heater wall is: 𝑄̇ 𝑙𝑜𝑠𝑠 in insulation can be determine by using this equation: 𝑄̇ =

𝑘𝐴𝑠 ∆𝑇 𝑑

,

Where; k = thermal conductivity of polyethylene (0.035 W/mK) Awater heater = L x W= 0.15 x 0.15 = 0.0225 m2 55

∆𝑇 = Changes of temperature (10˚C) d = Thickness of insulation used 0.035 𝑥 0.0225 𝑥 (273) 𝑄̇ 𝑙𝑜𝑠𝑠 = 0.0175

𝑄̇ 𝑙𝑜𝑠𝑠 = 145𝑤 ̇ = 𝑇𝑜𝑡𝑎𝑙 𝑝𝑜𝑤𝑒𝑟 𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑 − ℎ𝑒𝑎𝑡 𝑙𝑜𝑠𝑡 𝑡𝑜 𝑠𝑢𝑟𝑟𝑜𝑢𝑛𝑑𝑖𝑛𝑔 𝑄𝑛𝑒𝑡 = 1500W - 145W = 1055W Net heat supplied to water = Heat absorbed by the copper tube 𝑄𝑛𝑒𝑡 = 𝑄̇ 1055 = 416L Length of copper pipe required in the water heater in order to reach an output temperature of 40℃, L = 1055/416 = 2.54m Validation of this project can be refer to Appendix Q. Please refer to Appendix S for fan selection and calculation. Refer to chapter 7 for safety, hygiene and maintenance issue.

56

3.8 Detailed Design

Figure 3.13: Complete Engineering Drawing

57

Dimension (length x width x height): 1600mm x 850mm x 750mm Operation Time: 12 hours Production Rate: 125kg/5days Part of Components: 

Solar Collector



Dryer Chamber



Water Heater

3.8.2 Bill of Material Solar Collector Table 3.14: BOM of Solar Collector Bill.

Materials

Quantity

1.

Acrylic (Solar collector cover)

1

2.

Copper plate (Solar absorber)

1

3.

Styrofoam (Insulation)

1

4.

Local wood (Frame)

5

5.

Wire mesh (Air inlet)

1

Water Boiler Table 3.15: BOM of Water Boiler Bill.

Materials

Quantity

1.

Stainless steel 316 (Tank structure)

1

2.

Copper coil (Water heating element)

1

3.

Styrofoam (Insulation)

1

Connection Pipe Table 3.16: BOM of Connection Pipe Bill.

Materials

Quantity

1.

Aluminium Pipe

1

2.

Tubular pipe insulator

1 58

Drying Chamber Table 3.17: BOM of Drying Chamber Bill.

Materials

Quantity

1.

Aluminium 3003 Alloy (Trays frame)

25

2.

Aluminium 3003 Alloy (Trays)

24

3.

Aluminium 6060 (Trays support)

1

4.

Aluminium 6060 Alloy (Trays support)

1

5.

Polycarbonate Sheet (Insulation and chamber cover)

1

6.

Styrofoam (Insulation)

1

7.

ASTM A36 (Frame support)

1

8.

Caster wheel (2 swivel, 2 break)

1

9.

Door hinge

4

10.

Door latch

1

11.

Simple door handle

2

12.

Load Cell

1

13.

Thermocouple

1

14.

PLC

1

59

Figure 3.14: Structure of Bill of Materials

60

Component and Sizing Solar Collector Table 3.18: Component Sizes in Solar Collector Bill.

Materials

Sizing

1.

Acrylic (Solar collector cover)

1m x 1.5m x 0.001m

2.

Copper plate (Solar absorber)

1m x 1.5m x 0.001m

3.

Styrofoam (Insulation)

2m x 1.5m x 0.02m

4.

Local wood (Frame)

1m x 0.3m x 0.03m 1.5m x 0.3m x 0.03m 1m x 1.5m x 0.03m

5.

Wire mesh (Air inlet)

2m x 4m

Water Boiler Table 3.19: Component Sizes in Water Boiler Bill.

Materials

Sizing

1.

Stainless steel 316 (Tank structure)

300mm x 450mm x 300mm

2.

Copper coil (Water heating element)

length: 1100mm

3.

Styrofoam (Insulation)

2m x 1.5m x 0.02m

Connection Pipe Table 3.20: Component Sizes in Connection Pipe Bill.

Materials

Sizing

1.

Aluminium Pipe

10 cm dia. x 3 m

2.

Tubular pipe insulator

10 cm dia. x 3 m

61

Drying Chamber Table 3.21: Component Sizes in Drying Chamber Bill. 1.

Materials Aluminium 3003 Alloy (Trays frame)

Sizing (810x785x1) m (4744x1650x1) m

2.

Aluminium 3003 Alloy (Trays)

(750x750x1) m

3.

Aluminium 6060 (Trays support)

(1644.8x480x1) m

4.

Aluminium 6060 Alloy (Trays support)

(1800x20x1.6) m

5.

Polycarbonate Sheet (Insulation and chamber cover)

(4764x1660x3) m

6.

Styrofoam (Insulation)

(11656x25x3) m

7.

ASTM A36 (Frame support)

3042x1656x12) m

8.

Caster wheel (2 swivel, 2 break)

4 inches

9.

Door hinge

4 inches

10.

Door latch

4 inches

11.

Simple door handle

4 inches

12.

Load Cell

-

13.

Thermocouple

-

14.

PLC

-

62

3.8.3 Product Design Specification Table 3.22: PDS of Drying Machine No.

Specification

Requirement

Design Achievement Approximately Less than RM5000 Total cost RM5000 RM2449.44 15-20 square feet Use portable machine (length x width x as improvement height): 1600mm x 850mm x 750mm Must able to fit 60 kg of Able to fit more than Production rate fresh berry. 80 kg of fresh berry. :125kg/5days

1.

Cost

2.

Size

3.

Capacity

4.

Rate of drying

5.

Temperature

6.

Not affect the Varied temperature. quality of peppers

7.

8.

9.

10.

11.

12.

Have a better drying rate than conventional drying (sun drying method) Less than 3 to 5 days. Use suitable temperature approximately 40degree Celsius

Preferences

Less than a day.

12 Hours

Operate at optimum 37 – temperature where the Celsius moisture can evaporate easily.

43-degree

After certain of time, High Food Quality (outside of berries dry) the air temp should be reduced. Insulation Withstand high Use material has low High Insulation temperature to prevent thermal conductivity. heat loss. Water proof To prevent the quality Design with sealing by High Waterproof of berries from using water proof Material deteriorated. material. Ventilation Able to maintain low Use temperature of 40- Good Ventilation humidity and maintain degree Celsius and system by using 4 optimal temperature. moisture content lower fans than 12%. Heat transfer Uniform heat Integrate radiation, Uniform Heat Flow distribution. conduction and and Temperature convection. Distribution Material Comply to CODEX Usage of material. For Comply CODEX standard. example, stainless Standard steel, polycarbonate Food safety Not hazardous Not react chemically Non-Hazardous (CODEX) with food

63

13.

Aesthetics

Attractive appearance.

The component used to Good Appearance improve the aesthetic features will not reduce the efficiency of the dryer. Consider human height Suitable for farmer

14.

Ergonomically

Adapt human comfort

15.

Environment

Environmental-friendly

Does not pollute the Hybrid environment. Source

16.

Power source

Renewable sources

Solar energy

Heating

Using Electrical Energy and Solar Energy

3.8.4 Final Cost Estimation Solar Collector Table 3.23: Price List of Solar Collector Bill.

Materials

Cost

6.

Acrylic (Solar collector cover)

RM70

7.

Copper plate (Solar absorber)

RM285

8.

Styrofoam (Insulation)

RM6.50

9.

Local wood (Frame)

RM35

10.

Wire mesh (Air inlet)

RM19

Water Boiler Table 3.24: Price List of Water Boiler Bill.

Materials

Cost

4.

Stainless steel 316 (Tank structure)

RM110

5.

Copper coil (Water heating element)

RM260

6.

Styrofoam (Insulation)

RM6.50

Connection Pipe Table 3.25: Price List of Connection Pipe Bill.

Materials

Cost

3.

Aluminium Pipe

RM225.40

4.

Tubular pipe insulator

RM42.50 64

Drying Chamber Table 3.26: Price List of Drying Chamber Bill.

Materials

Sizing

15.

Aluminium 3003 Alloy (Trays frame)

RM20.53

16.

Aluminium 3003 Alloy (Trays)

RM117.89

17.

Aluminium 6060 (Trays support)

RM440.64

18.

Aluminium 6060 Alloy (Trays support)

RM28.84

19.

Polycarbonate Sheet (Insulation and chamber cover)

RM49.75

20.

Styrofoam (Insulation)

RM298.66

21.

ASTM A36 (Frame support)

RM15.70

22.

Caster wheel (2 swivel, 2 break)

RM6.50

23.

Door hinge

RM4.08

24.

Door latch

RM15.92

25.

Simple door handle

RM16.18

26.

Load Cell

RM3.80

27.

Thermocouple

RM40.77

28.

PLC

RM4.08

Total Cost = 2449.44

65

3.10 Mechatronics: As an introduction, mechatronics is a multidisciplinary field of science which includes the mechanical, compute, electronics, telecommunications, system and control engineering. Originally, mechatronics is just a combination of mechanical and electronics but as technical systems becomes more and more complex, the definition has been broadened to include the areas of engineering as said before. The aspects of mechatronics that we will look and discuss for this project of pepper dryer machine includes the topics on the schematic diagram of the pepper dryer machine which shows the working components of the dryer and its functions, connections, how some part of the components are setup into the dryer, and the flow diagram for the main method and alternative method of drying for the dryer. 3.10.1 Schematic Diagram:

Figure 3.15: Product schematic diagram

66

Legend: 1. Drying Chamber 2. Inlet Fan 3. Outlet Fan 4. Trays 5. Solar Collector 6. Water Heater Heat Exchanger 7. Heating Coil 8. Support Stand 9. Load Cell 10. Wheels 11. Thermocouple 12. Programmable Logic Controller (PLC) 13. Alternative Current Power Source 14. Pressure Valve Symbol: Energy Air Flow 3.10.2 Functions of the components: The Drying Chamber is used to isolate the trays from the outside environment. The A/C power supply is used to supply electrical energy to the PLC and the rest of the electrical components. The inlet fan is used to draw air into the drying chamber while the exhaust fan is used to exhaust air out of the drying chamber. The trays are used to hold the berries during drying process while the solar collector and water heater heat exchanger are used to provide heating to the drying chamber. Heating coil is used to heat the water inside the water heater heat exchanger. The load cells are used to determine the weight and the thermocouple is used to determine the temperature.

67

3.10.3 Setup and working of the components: The setups for the load cells (4 of them) are each put on a steel plate between the wheels and the support above it and then connected to the PLC. The purpose of this is so that we can measure and detect the weight of the dryer including its support in real time. The loss in weight measured using the load cells during the operation of the dryer will indicate the loss in weight of the pepper berries inside the drying chamber. When the weight loss are at 33% of the initial weight (at the start of the drying process), all of the drying components will be stopped and the drying process is done. The setup for the heating components includes the thermocouple and the heating coil. Both of these components will be placed inside the water heater heat exchanger and connected to the PLC. The thermocouple will detect the temperature of the water inside the water heater heat exchanger and then the value of the temperature measured will determine the amount of current supplied to the heating coil. This is so that the amount of heat produce by the heating coil can be adjusted accordingly which then can affect the temperature inside the drying chamber. The pressure valve is connected to PLC so that it can be released when prompted. The setup for the inlet and exhaust fans is that for the inlet fans, they are place at the openings connecting the drying chamber to the pipe of the water heater heat exchanger and solar collector pipe. While, the exhaust fans are placed at the wall opposite to the side of the inlet fans for the drying chamber. The fans are also connected to the PLC. The purpose of this is to control the RPM of the fan so that the speed of intake and exhaust of air can be controlled accordingly to increase or decrease the temperature inside the drying chamber. The programmable logic controller (PLC) is connected to the a/c power supply. This is to provide the electrical energy to the PLC and the rest of components connected to the PLC for them to work. The PLC requires some setup in order for it to function as desired for this pepper dryer machine. First, the PLC needs to be configured by doing some programming to it. The programming of the PLC is done through the software given by the manufacturer using a computer (usually a personal computer). The languages that are used to configure the PLC is divided into two; which are textual language and graphical language; with graphical based language to be more simple and convenient. This is because graphical based language includes all the necessary functions and functional 68

blocks in the standard library of the PLC software. These functions include the timers, counters, strings, comparators, numeric, arithmetic, bit-shift, calling function and many more. Then, after the programming is done on the computer, it will be uploaded into the PLC. A series of test and fix may need to be done as the program might not work and need to be tuned for the machine, especially for the load cell where the weight of the drying chamber with support stand may varies. 3.10.4 Flow Diagram (Using only the solar collector): Below shows the flow diagram for the drying when only solar collector is being used.

Figure 3.16: Flow diagram (Solar collector used) The weighing system functions as shown above that the load cell will signal to the PLC to switch off all the equipments when the weight of the drying chamber, W 69

decreases by 30% of its original weight when it is fully loaded. The temperature regulator on the other hand will regulate the temperature inside the drying chamber between 43-37 degrees Celsius by measuring the temperature of the drying chamber, TC and then changing the input current into the heating coil and control the speed of the inlet or outlet fan accordingly to increase or decrease the temperature of the drying chamber. 3.10.5 Flow Diagram (Using the Solar Collector and the Water Heater Heat Exchanger): Below shows the flow diagram for the drying process when the solar collector and the water heater heat exchanger is used at the same time or when only the heat exchanger is being used.

Figure 3.17: Flow diagram (Solar collector and Water heater used) As for this condition where the water heater heat exchanger is used alone or together with the solar collector, there are only two additional system added into the machine compare to the previous method. The two systems are the boiling indicator 70

where the thermocouple will measure the water temperature, TW and signal the PLC to release the pressure valve when the water reaches 100 degrees Celsius. The second system added into the machine for this condition is the manual refilling of the water into the water heater heat exchanger where the water will be refill every 30 minutes.

71

CHAPTER 4

MODELLING AND SIMULATIONS

Model and simulation were most common in sciences to the imitation of a situation or process. In this IDP Projects, a CFD simulation can be the powerful scientific tool to simulate the heat flow and distribution inside the solar collector and drying chamber. CFD is the analysis, by means of computer-based simulations of the systems involving fluid flow and heat distribution. CFD was the alternative way instead of the experimental to be done. But the results often qualified as “mere” simulation not to be mistaken for the “real thing”. The CFD simulation was an ideal control environment. In heat transfer, CFD simulation was a rational model that handle the important heat transfer as well as experimental observations. CFD simulation also a fundamental tool for ensuring that a holistic understanding of the temperature distribution and accumulation. CFD is a procedure that approximate and analyses the motion of the fluid. The focus of the analysis is the modelling of the solar collector and drying chamber. The software that will be used for modelling and analysis are Solidwork. The most important things to be done before proceeding with the modelling are the brainstorming process and designing process. The skills are needed in modelling and simulation in Solidworks from learning of how to use the software efficiently. So, these are the requirement for modelling and simulation take places. The simulation was to produce the temperature profile and velocity process inside the solar collector and drying chamber. CFD is a procedure to approximately and analyses the motion of the hot air. There are three keys components involve which are governing equation, computational grid (mesh), and boundary condition. The equation that involves is Naiver-Stokes 72

Equation. The Naiver-Stokes Equation describe the flow of fluid and temperature distribution, also is Newton’s second law of motion for fluids. 𝜕𝑢 2 𝜌 ( + 𝑢 ∙ ∇𝑢) = −∇𝑝 + ∇ ∙ (𝜇(∇𝑢 + (∇𝑢)𝑇 ) − 𝜇(∇ ∙ 𝑢)𝐼 + 𝐹 𝜕𝑡 3 Equation 4.1: Naiver-Stokes Equation Where: u – fluid velocity p – fluid pressure ρ – fluid density µ - fluid dynamic viscosity The Navier-Stokes equation is used for solving a set of boundary condition (such as inlets, outlets, and walls). Because of the complexity, the equation only admits a limited number of analytical solutions. The Navier-Stokes equation is solved together with the continuity equation. The Navier-Stoke equation represents the conservation of momentum, while the continuity equation represents the conservation of mass. 𝜕𝜌 + ∇ ∙ (𝜌𝑢) = 0 𝜕𝑡 Equation 4.2: Continuity Equation Mesh generation play the important roles to construct the CFD simulation. A computational domain is chosen, and a mesh is generated. The solar collector and drying chamber domain is divided into many small elements called cells. Meshing consist of 3 types meshing which is 4 noded tetrahedral, 6 noded prisms, and 6 noded hexahedral. In this study, the 4 noded tetrahedral and 6 noded hexahedral is consider generating the mesh. Based on Zeya A. Q. et. al. (2013), the tetrahedral meshing has been preferred over any other because it produces more accurate results than quadrilateral due to the non-uniform geometrical shape of the model under investigation. The boundary condition is an initial condition to define a problem. Based on Ningbai Ningbai (2011), the general boundary condition is divided into three types which are a Dirichlet boundary, Neuman boundary, and Mixed boundary. The Dirichlet boundary is sets known constant on the boundary. The Neuman boundary is sets known derivative on the boundary. Lastly, the mixed boundary is sets of the condition the above two types on the boundary. Hence, in this study, the chosen boundary condition is the first type of boundary condition being used. 73

Flow Chart of Simulation Process:

Figure 4.1: Flow Chart of Simulation Process

74

Preliminary Design – For the solar system and drying chamber system, it is important to have a model based design approach for initial specification in later development. Modelling – Design the computational aided design (CAD) model using Solidworks for the water heater, solar collector and. The dimensions of the model also must be following the real design specification. Solution phase– Type of analysis in ANSYS Workbench is selected and then been dragged it towards the imported geometry. The velocity profile and temperature profile was generated. Post-simulation – The data from the simulation can be visualized in form of flow simulation and temperature distribution for the system. Analysis and synthesis – Analyze the result data from simulation Modelling

Figure 4.2: Modelling of Water Heater System

Figure 4.3: Modelling of Solar Collector

75

Figure 4.4: Modelling of Drying Chamber

Results of CFD simulation 1. Simulation of Solar Collector Velocity Profile

Figure 4.5: Velocity profile of solar collector The above figure was the simulation on velocity profile on the solar collector. This simulation was to simulate the flow of the outside air flow through the inlet of the system. This simulation was very important to prove that the design was suitable to achieve maximum efficiency on flow hot air to operate the system. From the figure, it was shown that the velocity of the air inside the system was approximately 0.3m/s across the resistance inside the system. It was because of the air was driven by the fan. The fan was to suck the outside air at the outlet of the system.

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The velocity of the fan was set and fixed at 3m/s to make sure that the air was hot enough to transfer it to the drying chamber. 2. Simulation of Solar Collector Temperature Profile

Figure 4.6: Temperature profile of solar collector

The above figure was the simulation of temperature distribution on the solar collector. This simulation was to simulate the temperature distribution of the outside air flow through the inlet and the resistance of the system. The figure showed that the approximate temperature of the air that flow inside the system was 313.33 Kelvin. The distribution of the temperature was described that the design was efficient in term of temperature absorption. It was proved that with the design, the temperature achieved was suitable for the application of the drying process.

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3. Simulation of Drying Chamber Velocity Profile

Figure 4.7: Velocity profile of drying chamber

The above figure was the simulation on velocity profile in the drying chamber. This simulation was to simulate the flow of the outside air flow through the inlet of the system. From the figure, it was shown that the velocity of the air inside the system was approximately 0.3m/s across the system. The initial boundary condition at the inlet pipe is set at uniform mass flow rate of 0.047kg/s as obtained based on thermofluid analysis in section 3.7.2. Mass flow rate is chosen as the boundary condition because the fluid involved is air, which is compressible flow. Mass flow rate will remain relatively constant throughout the flow as compared to volume flow rate as volume or density in compressible flow will varies with slight change in temperature. The outlet boundary condition is set at environmental pressure of 101325Pa as the air is driven to the surrounding, which is exposed to atmospheric pressure. The design of the inlet and the outlet of the air to the drying chamber was very efficient. It was proved through the simulation. The flow of the air was cover most of the area inside the drying chamber. The velocity inside the drying chamber also was suitable for the application of the process. it was proved with the calculation analysis

78

that, the 0.3 m/s was the best velocity in order to dry the barriers and achieved a high quality of dried barriers. 4. Simulation of Drying Chamber Temperature Profile

Figure 4.8: Temperature profile of drying chamber The above figure was the simulation of temperature distribution inside the drying chamber. This simulation was to simulate the temperature of the outside air flow through the inlet of the system. The condition set in this simulation is the useful power input (0.9264kW) from the solar collector, based on analysis obtained from thermofluid (Section 3.7.2). The initial and outlet conditions remained the same as simulation of velocity profile. From the figure, it was shown that the design of the inlet and the outlet of the air to the drying chamber was very efficient. It was proved through the simulation. The temperature was distributed inside the drying chamber that enough for the drying process of fresh pepper barriers. As shown in the figure, the temperature inside the system was approximately 40℃ and minimum temperature was 31.11℃. It was proved that the design was suitable for the operation because of the temperature distribution was achieved and prove on the simulation. Please refer to Appendix J for detailed bending analysis simulation and the bending calculation.

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CHAPTER 5

MATERIALS SELECTION Materials selection for the product was based on several reasons. This subtopic can be divided into four parts which will summarize the whole parts of materials selection. 

Solar collector



Water boiler



Drying chamber



Connection pipeline

5.1 Solar collector

Acrylic Styrofoam

(solar collector cover)

Local wood

Copper plate (solar absorber)

Wire mesh Figure 5.1: Materials label for solar collector 80

Table 5.1: Materials used for solar collector Materials

Reasons

Dimension

Price

Acrylic

Acrylic vs Polycarbonate

1m x 1.5m x 0.001m

RM 70

(Solar collector



cover)

Lighter, cheaper, better emissivity, same

(1 pc)

thermal conductivity, strong enough for this application.

Copper plate



(Solar absorber)

Highest thermal conductivity (2x than Al)

1m x 1.5m x 0.001m

compared to other typical heat absorbing

(1 pc)

RM 285

materials, easy to handle for fabrication, available in local market. Styrofoam (Insulation)

Styrofoam vs Fiberglass 

Light, cheap, easier to handle, safer to

2m x 1.5m x 0.02m

RM 6.50

(1 pc)

handle, higher thermal resistance value, better weather resistor. Local wood



(Frame)

Cheap, widely available, strong enough

1m x 0.3m x 0.03m

for this application

(2 pcs)

RM 35

1.5m x 0.3m x 0.03m (2 pcs) 1m x 1.5m x 0.03m (1 pc)

Wire mesh (Air inlet)



To prevent any entering of obvious

RM 19

contaminants or bugs into the product.

81

5.2 Water Heater Heat Exchanger Stainless steel 316

Copper coil

Styrofoam

Aluminium tube Figure 5.2: Materials label for water boiler

Table 5.2: Materials used for water boiler Materials

Reason

Dimension

Price

RM 110

Stainless steel



High yield and tensile strength

300 x 450 x 300)

316



Has good corrosion resistance

mm



Good conductor of heat thus

length: 1100mm

RM 260

Light, cheap, easy to handle, high

2m x 1.5m x 0.02m

RM 6.50

thermal resistance value.

(1 pc)

(Tank structure) Copper coil (Water heating

results in loss of heat (release heat

element)

to heat up the water in the water tank).

Styrofoam (Insulation)



82

5.3 Drying chamber

Aluminium sheet

Polycarbonate sheet

Styrofoam

Aluminium 3003 (Trays)

Aluminium 6060

Caster wheel

(Trays support)

ASTM A36 Figure 5.3: Materials label for drying chamber

83

Table 5.3: Materials used for drying chamber Material

Reasons

Aluminium 3003 Alloy (Trays frame)



Aluminium 3003 Alloy (Trays) Aluminium 6060 (Trays support)



Aluminium 6060 Alloy (Trays support)

Size, m

Good heat conductivity for food drying application and lighter than steel.

810x785x1

Quantity Total Price 24 20.53

4744x1650x1

1

117.89

750x750x1

24

440.64

Good durability to support force from berries and trays.

1644.8x480x1

1

28.84

1800x20x1.6

1

49.75

Polycarbonate Sheet (Insulation and chamber cover) Styrofoam (Insulation)



Good heat insulation and strong

4764x1660x3

1

298.66



11656x25x3

1

15.70

ASTM A36 (Frame support)



Caster wheel (2 swivel, 2 break) Door hinge



Light, cheap, easy to handle, high thermal conductivity High ultimate strength to support force from upper section of drying chamber. Mobility Loading and unloading process



Door latch

3042x1656x12 1

6.50

4 inch

1(set)

4.08

4 inch

4

15.92

4 inch

1

16.18

4 inch

2

3.80

To determine the weight loss from early and end process. Determine temperature

-

1

40.77

-

1

4.08

Control the temperature of water boiler

-

1

326.20

Simple door handle Load Cell



Thermocouple



PLC



5.4 Pipeline connection For the pipeline, the material will be aluminum since it has higher melting point compared to ordinary pipeline which mostly used PVC. PVC starts to decompose when the temperature reaches 140 °C, with melting temperature starting around 160 °C. Since the PVC has a bit higher melting point than our temperature inside the chamber, but it has very low glass transition temperature, 82 °C, which may reduce the efficiency of the ventilation. 84

Furthermore, we will be conducting high temperature constantly, so every precaution must be considered. For aluminium, the melting point is Tal,melt: 660.3 °C which is quite high. Therefore, this will safe for selecting aluminium to be used for pipeline to carry the hot air of 40 °C. Furthermore, the thermal expansion of aluminium also very low at the given temperature when conducting hot air.

When discussion of corrosion, the aluminium also has a very good corrosion resistance as the result Aluminium Oxide (AlO) layer forms at the surface of the aluminium. Therefore, the hot air will not carry any rust contaminant from the surface of the aluminium pipeline. Table 5.4: Materials used for pipeline connection Material

Aluminium pipe

Reason

  

Tubular pipe insulator

 

Dimension

Total Price

Higher melting point compared to PVC Low thermal expansion Very good corrosion resistance

10 cm dia. x 3 m

RM 225.4

Light, cheap, easier to handle, good insulator Suitable for pipe-shaped

10 cm dia. x 3 m

RM 42.50

Total cost for materials needed = RM 2, 449.44

85

CHAPTER 6 MANUFACTURING SYSTEM .

6.1 Production Layout It is important to have a plant layout to decide where to place the machines, facilities, equipment and staff in a factory. For this project, we choose cellular layout because it can reduce the time setup and less space consumption compared to the conventional way. Cellular layout is defined as application of group technology where dissimilar machines or processes are aggregated into cells, which each is dedicated to the production of a part family or limited group of families. Cellular layout is suitable for batch production, where a batch of pepper is produced for a specified quantity, suit the cellular layout criteria. Figure 6.1 shows the process which occurs in the production of the pepper berries and Figure 6.2 shows the example for cellular layout that has been chosen.

Figure 6.1: Production layout of pepper drying.

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Figure 6.2: U-Shape machine cell

U-shape cellular layout is chosen because the process of drying required manual handling. For example, labours are needed at the loading and unloading stations. Weighing and packing process required human inspection as well. The physical arrangement is convenient for workers to move the pepper berries from one station to another station within a shorter distance as compared to inline cellular layout, in which machine cells are arranged in a straight line, with input and output stations arranged at the two extremes. Inline cellular layout is more suitable for automated manufacturing system whereby the intermediate products are moved by automatic system. For the control system of the plant, hybrid system is applied. Hybrid system consist of centralized and decentralized system. As for the machine, decentralized system is used. This is because it will be much easier to control if anything happens to one of the function. For example, when the water heater is not functioning, the function will then change to solar heater which attached at the drying chamber. It is also to make sure that the drying process can be done consistently even during the rainy season or night time. 6.2 Production Rates The production rates for the machine can produce is 80 kg per day, based on the cycle time of 12 minutes per kg for 8 working hours. According to the information from the Malaysian Pepper Board (MPB), it is said that by using conventional way, the quantity of pepper dried is 300 kg for 5 days. Which means that in one day, they approximately dried 60 kg of pepper. It can be observed that the conventional way produced less compared to using the pepper drying machine. One machine consists of 24 trays and one tray can be filled up to 1.71kg of pepper berries.

87

For conventional: 𝐶𝑦𝑐𝑙𝑒 𝑡𝑖𝑚𝑒 =

120 ℎ𝑜𝑢𝑟𝑠 ℎ𝑜𝑢𝑟𝑠 = 0.4 = 24 𝑚𝑖𝑛𝑢𝑡𝑒𝑠/𝑘𝑔 300 𝑘𝑔 𝑘𝑔

𝑀𝑎𝑥. 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑝𝑒𝑟 𝑑𝑎𝑦 =

60 𝑚𝑖𝑛𝑢𝑡𝑒𝑠 × 24 ℎ𝑜𝑢𝑟𝑠 = 60 𝑘𝑔/𝑑𝑎𝑦 24 𝑚𝑖𝑛𝑢𝑡𝑒𝑠/𝑘𝑔

For automation (by using machine): Total tray = 24 trays, 1 tray = 1.71 kg Assume minimum working hours = 8 hours 𝐶𝑦𝑐𝑙𝑒 𝑡𝑖𝑚𝑒 =

8 ℎ𝑜𝑢𝑟𝑠 ℎ𝑜𝑢𝑟𝑠 = 0.2 = 12 𝑚𝑖𝑛𝑢𝑡𝑒𝑠/𝑘𝑔 41 𝑘𝑔 𝑘𝑔

𝑀𝑎𝑥. 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑝𝑒𝑟 𝑑𝑎𝑦 =

16 ℎ𝑜𝑢𝑟𝑠 × 60 𝑚𝑖𝑛𝑢𝑡𝑒𝑠 = 80 𝑘𝑔/𝑑𝑎𝑦 12 𝑚𝑖𝑛𝑢𝑡𝑒𝑠/𝑘𝑔

Percentage of improvement: Let 𝑃𝑎 = Maximum production rate using machine and 𝑃𝑐 – maximum production rate using conventional way of drying. 𝑃𝑎 −𝑃𝑐 𝑃𝑐

=

× 100%

80−60 60

× 100%

= 33.3% Based on calculation, the efficiency of using machine in drying pepper berries has increased the production rates by 33.3%.

Quantity of pepper berries produced (kg)

Comparison in production using conventional drying and machine drying 600

480

500

400

400 300 200

100

60 80

160 120

1

2

3

300

4

360

120

100

80

60

40

20

0

240 180

320 240

5

6

Number of day Conventional Drying (kg) Machine Drying (kg) Difference in production quantity (kg)

Figure 6.3: Comparison on production using different methods of drying 88

From Figure 6.3, by considering the maximum production rate for 6 days, it can be seen that 240kg of pepper berries can be produced in 3 days with the aid of machine while conventional way of drying needs 4 days to reach the same amount of pepper berries. On the sixth day, the total difference in production is 120kg, which is the amount produced by using conventional way for two days. In other words, we have shorten two days of drying time by using machine. In short, using machine can increase the production rate of pepper berries. Operation time of one tray = 8 hours ÷ 24 trays = 0.33 hours = 20 minutes Tc = To + Th + Tth

Tc = Cycle time

Tc = 20 + 2 = 22 minutes

To = Operation time = 20 minutes Th = Handling time = 2 minutes Tth = Tool utilization

Production rates (Batch production): Tb = Tsu + QTc Tb = 5 + (24)(22)

Tb = Time per batch

Tb = 533 minutes/tray

Tsu = Setup time = 5 minutes Q = Number of trays = 24 Tc = Cycle time for one tray = 22 minutes

𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑡𝑖𝑚𝑒 𝑝𝑒𝑟 𝑤𝑜𝑟𝑘 𝑢𝑛𝑖𝑡, 𝑇𝑝 = 𝑇𝑝 =

𝑇𝑏 533 = = 22.21 𝑚𝑖𝑛𝑢𝑡𝑒𝑠/𝑡𝑟𝑎𝑦 𝑄 24

𝐻𝑜𝑢𝑟𝑙𝑦 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑟𝑎𝑡𝑒, 𝑅𝑝 = 𝑅𝑝 =

𝑇𝑏 𝑄

60 𝑇𝑝

60 𝑡𝑟𝑎𝑦 = 2.7 ≈ 3 𝑡𝑟𝑎𝑦𝑠/ℎ𝑜𝑢𝑟 22.21 ℎ𝑜𝑢𝑟

89

Plant Capacity: Assuming that the farmer works 2 shifts in a day and 5 days in a week; PC = N × S × H × Rp

N = Number of machines = 1

PC = (1)(10)(8)(3)

S = Number of shifts/wk = 10

= 240 trays/week × 52 weeks

H = number of hour/shift = 8

= 12,480 trays/year × 1.71 kg

Rp = 3 trays/hour

= 21,340.8 kg/year Based on the calculation, the dried pepper berries produced in conventional way is 60 kg per day while the quantity which produced by the machine is 80 kg per day. Therefore, the production of the pepper berries is increased up to 25% by using the drying machine. 6.3 Comparison between Conventional and Automation Conventional way of production usually required higher setup time compared to automation. In conventional production, 2 to 3 workers are needed but in automation, only one worker is needed to operate the machine. For the automation, the only setup time needed is during filling up the trays with pepper berries. Since the machine consist of hybrid system, so the farmer does not depend fully on the weather and the drying process can be continued by using the water heater. Hence, this can increase the production of the dried pepper. Table 6.1 shows the difference between conventional and automation way of drying pepper. Table 6.1: Comparison between conventional and automation of drying pepper Conventional

Automation

High setup time

Low setup time

More workers needed

Less workers needed

High space consuming

Low space consuming

6.4 Type of Storage System & Material Handling Once dried, the black pepper is stored in jute bags or sealed containers. The storage area need to be kept in cool, dry and clean to keep the pepper hygienic and able to maintain its moisture content. The storage equipment used is the conventional storage

90

way which is rack system. Rack system stack the unit loads vertically without the need of the loads themselves to provide support. We will be using 2-tiers pallet rack, one of the common rack system, which consist of a frame that includes horizontal load supporting beams. 2-tiers is chosen instead of 3 because it may be hard to keep the dried pepper at a high place in order to prevent any accident which may occur if the jute bag fall off the rack. Figure 6.4 shows the standard size of pallet used. It can withstand up to 2000kg of mass. Figure 6.5 shows the size of the rack which measured based on the standard pallet. One rack can occupied 2 pallets and on one pallet can hold 2 to 4 bags of dried pepper.

Figure 6.4: Measurement of the pallet used.

Figure 6.5: 2-tier pallet rack

91

As for the handling system, where the loading and unloading of the pepper berries, workers are needed to drive the forklift or pallet jack which is used to bring the fresh pepper berries to the drying machine. Another worker is needed to fill the machine with peppers and distribute it on the tray evenly. As the drying process has been done, the worker will put the dried pepper berries into the container or jute bag and placed on the pallet. By using forklift, the pallet will then be arranged at the rack provided. Figure 6.6 shows the forklift and Figure 6.7 shows the pallet jack.

Figure 6.6: Forklift

Figure 6.7: Pallet Jack

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CHAPTER 7

PROFESSIONAL AND ETHICS For professional and ethics, our group have designed the EZ dryer with prioritizing the safety issues, ergonomics of the machine, user friendly, manual for conducting the machine and many more. These all criteria are important due to maximize the efficiency of the machine. Also, our product was designed to make it user friendly by considering ergonomics aspect. 7.1 Manual for worker Sunny day 1. Fill the tray with pepper berries and put it inside the drying chamber. 2. Close the door of the drying chamber and lock it. 3. The machine will be placed where it can have exposed most with the sunlight. 4. The solar collector must be facing or can catch most of the sunlight. 5. The solar collector can be moved according to the direction of the sunlight. 6. Fill the water heater with water until it is ¾ from the total volume. 7. When the water is boiled, switch on the ventilation system. 8. After the berries are dried, the ventilation and the boiler system must be switch off. 9. Unlock the door and open the chamber to remove the heat. 10. Collect the dry pepper.

93

Night and rainy day 1. The fill the water heater until ¾ full. 2. Fill the tray with pepper berries and put it inside the drying chamber. 3. Close the door of the drying chamber and lock it. 4. After the water is boiled, switch on the ventilation system. 5. After the berries are dried, the ventilation and the boiler system must be switch off. 6. Unlock the door and open the chamber to remove the heat. 7. Collect the dry pepper. 7.2 Maintenance Maintenance of the machine can be done by the worker or user for the machine. Since the machine does not involve any complex parts, it is easy to repair the machine as well as maintaining the machine in the optimum condition. The manual of the machine is shown in table below. Before doing the maintenance or repairing the machine, it must be: 1. Switch off all the electric or power supply. 2. Make sure the machine is not loaded. 3. The problem is identified. 4. The new replacement must follow the dimension, material selection and analysis from the report. 5. The replacement parts must have SIRIM or standard certificate. Table 7.1: Machine user manual Parts

Procedure

Chamber Door

Door

(The door of the machine can self-

1. Open the chamber’s door.

made according to the dimension,

2. Unscrew the door from the chamber.

material selection and analysis from

3. Replace with the new one and attach

the report)

to the chamber.

94

Tray

Tray

(The tray of the machine can self-

1. Unloaded the tray from the chamber.

made according to the dimension,

2. Replace with the new one.

material selection and analysis from the report) Ventilation system Ventilation motor

Ventilation motor

(The ventilation motor can be

1. Disconnect the wire and cable of the

purchase from the local supplier

power supply from the ventilation

according to the dimension and

motor.

analysis from the report. The

2. Unscrew

ventilation motor must have SIRIM

chamber.

or standard certificate)

the

motor

from

the

3. Attach the new replacement of the ventilation motor. 4. Connect the wire or cable of power supply to the motor.

Pipeline (The pipeline can be purchased from the local supplier according to the dimension, material selection and analysis from the report)

Pipeline 1. Cut the broken pipeline from the machine. 2. Connect the new pipeline to the machine. The connection can be made by welding.

Water boiler

1. Disconnect the wire and cable of power supply from the water boiler. 2. Ensure the water boiler is empty and no water content. 3. Replace the heating element with new one. The heating element can be purchased

from

local

supplier

according to the analysis from the report. 4. Connect the wire and cable of the power supply to the water boiler. Solar collector

1. Remove the broken parts, wall or glass.

95

2. Replace with new one. Can be purchased

from

local

supplier

according to the analysis from the report. 3. Secure the new replacement.

7.3 User friendly EZ-dryer designed to meet all the aspect to make it user friendly. The product that are user friendly is very important due to make it very convenient for the user use the product. Table 7.2: Product’s user friendly aspects Aspect

Reason

Easy to use

EZ-dryer is a simple machine that easy to use for farmer. It does not involve any complex task or special procedure to run the machine. It was designed for user to easily on how the machine is work and how to use it.

Simple operation

Our machine also designed based on simple operation. Due to simple operation, the machine does not require complex operation and needed much special purposes part. This will make the machine easy to maintain and low cost for maintaining. Plus, the simple operation

will

make

the

user

easily

understand on how the machine is work, so they can adapt very fast and easily on how to use the machine. Noise produce

The EZ-dryer does not using any high-power motor to operate the machine. The machine only using moderate power ventilation motor and fan. Thus, when the machine is operating, it does not produce loud noise. 96

Therefore, this machine is convenient to use since it does not disturb the user by mean of the noise produced.

7.4 Ergonomics For our product, EZ-dryer, it has been designed followed by analysis to make sure it satisfied the ergonomics criteria. The ergonomics term relating to or designed for efficiency and comfort in working environment when conducting the machine. Therefore, there is several aspects that putted into when designing this machine. Tray arrangement, weight and span The tray was designed to ensure it is ergonomics enough to make the user comfort and avoiding any unwanted accident when conducting the machine. 

The highest height for the tray placement is 1.2-meter height. This is lower than average height of Malaysian. Therefore, the worker or user does not require a ladder or higher place when loading the tray. Also, the height is not low, and it is convenient for the user, so the user does not need to bend to much when loading the tray.



The span of the tray also not too long. This will make the worker not to span their hand long enough when loading and unloading the tray.



The weight of the tray is not too heavy as well. When the tray is loaded with the fresh berries, the total weight of the tray is 3.2 kg. This weight is not too heavy; therefore, the worker can easily lift the tray and load the tray into the drying chamber. Since the tray weight is not too heavy, the repetition for lifting the tray is not a big issue.

Labour For this machine, the required labour to operate the machine is about 1-2 workers only. Since the machine is easy to use and operate. It only requires less labour to operate the machine. To be specific, one worker can load the berries and other worker can set the placement of the machine. But all this task can be done by only 1 worker. 97

7.5 Safety The safety issue is the important criteria to be concern because any unwanted accident when operating the machine is best to be avoided. Therefore, all the safety issues must be analysed very carefully. The user or worker must follow all the manual when operating this machine to avoid any unwanted accident. But, the designing of this machine has followed the analysis to maximize the safety factor for the machine. Insulator 

All the wall for drying chamber, water boiler and solar collector have designed with polycarbonate and polyethylene insulator attached together. The insulator mainly to avoid any heat loss to surrounding to maximize the efficiency of the machine. Due to avoid the heat loss, this insulator can act as the safety factor as well. By attaching the insulator to the wall to most of the part and component of the machine, the machine will not too hot from outside. This will make the machine is safe to touch although the machine is still operating. Thus, if any mistouch to the machine will make the user safe and not catch skin burned by the hot surface.

Locker 

The door of the machine has been installed with locker. This locker will ensure the door of the drying chamber will not accidently opened. If the door is not accidently opened, the door will keep closed so that the heat collected inside the drying chamber will not escape when the machine is operating. The locking of the door of the chamber also for ensure there is no any insect or unwanted object enter the drying chamber. But the biggest reason for the locker is to ensure the user not catch the high temperature inside the drying chamber.

Wire insulator 

For this machine, to involve wire and cable to supply the electricity to run the water boiler and the ventilation of the machine. Since the machine is made from stainless steel and aluminium. That material is good electricity conductor. Therefore, if there is any short circuit, the person that touched the machine will experience electricity shock. Thus, the wire used for power supply is insulated to ensure there is not short circuit.

98

Components 

All the components of the machine such as, ventilation and water boiler have followed the standard and SIRIM certificate. By using components that followed the standard, the components are guaranteed safe to use. Plus, the socket to connect the power supply to the machine also have SIRIM certificate. As we know, the socket with SIRIM certificate must have circuit breaker. If the machine experienced the short circuit, the circuit breaker will disconnect the electricity to avoid damage to the machine.

7.6 Precautions of the machine 1. During the drying process: a. The door of the drying chamber must be closed all the time when the machine is operating. b. The sticker of warning to not open the door of the drying chamber used to warn to not the door when the machine is operating. The machine operating in high temperature.

Figure 7.1: Warning sticker 2. After the drying process is done: a. The door must be opened to release the heat. b. To avoid high temperature exposed to the user when unloading the tray after the drying process is done. c. The door must be opened 5 minutes after the drying process is done.

99

3. During loading and unloading: a. Use glove for loading and unloading of the tray to avoid the user’s skin not burned due to high temperature of the tray after the drying process is done and to avoid any injuries to worker and user if there are any sharp edges at the trays.

4. Do not cover the solar collector. a. To maximize the heat collected from the sunlight by the solar collector. b. To maximize the efficiency of the solar collector.

5. Carefully fill the water boiler with water to avoid any spillage. a. When filling the water boiler tank with water, the worker or user must carefully fill the water and avoid any spillage of water to outside component and wire at the water boiler. b. To avoid short circuit and electricity shock.

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CHAPTER 8

ECONOMIC ANALYSIS 8.1

Problem Statement EZ-Dryer is designed and have to be proceed to production. However, the price

of one machine is very important that it should be estimated in this section. Also, the estimated price and operating cost of the machine is needed to determine whether the farmer should invest in our machine or not. So, the analysis should be done to determine whether the investment is profitable and sustainable. 8.2

Production Theory Production theory explain how many product output the company can be

produced and with respect to the labour and the capital cost in the production. In this case, the machine production amount is estimated with labour and capital cost as an input variable. The production theory equation is given by: 𝑄 = 𝐴𝐾 𝛼1 𝐿𝛼2

(Equation 8.1)

A=Transform factor of input to output production. α=Constant of production theory K=Capital cost L=Number of labour days From data analysis estimation in Microsoft Excel (Appendix R), the value of A=2.25, α1=0.15 and α2=0.85. The machine production company spent RM300,000 on capital cost and 12 labour days in a month to produce the machine. The optimal 101

production output is to be determined. By substitute all the values into Equation 8.1, the optimal production output: 𝑄 = 2.25(300000)0.15 (12)0.85 𝑄 = 123 𝑢𝑛𝑖𝑡𝑠 From the results given, 123 unit of machine should be produced in the capital cost and labour employment. 8.3 Efficiency of Production Efficiency of production is divided into physical efficiency and economic efficiency. 8.3.1 Physical Efficiency Physical efficiency is related to the physical amount of all factors used in the process of producing some product. In this case, the system output is considered as the weight of the dryer and the system input is raw materials used in the production of the dryer. Physical Efficiency =

System output 𝑇ℎ𝑒 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑡ℎ𝑒 𝑚𝑎𝑐ℎ𝑖𝑛𝑒 𝑝𝑟𝑜𝑑𝑢𝑐𝑒𝑑. = System input 𝑇𝑜𝑡𝑎𝑙 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑟𝑎𝑤 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙𝑠 E=

50 kg 55 kg

E = 91% The calculation shows that 91% of the weight of raw materials is converted to the useful part of the machine while the remaining 9% of the raw materials is loss due to cutting process, grinding process and many other factors. 8.3.2 Economic Efficiency Economic efficiency measures the resource utilisation to generate revenue and every resource is fully utilised and reduce wastage. The calculation is shown as follow assume that 123 unit of machine is produced with RM4,000 selling price and RM309,831.12 as an investment to machine production system: 𝐸𝑐𝑜𝑛𝑜𝑚𝑖𝑐 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 =

𝑅𝑒𝑣𝑒𝑛𝑢𝑒 𝐼𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡 102

𝐸𝑐𝑜𝑛𝑜𝑚𝑖𝑐 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 =

123 × 4,000 309,831.12

𝐸𝑐𝑜𝑛𝑜𝑚𝑖𝑐 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 = 1.59 𝑜𝑟 159% The machine production company will gain 59% profit economically. 8.4 Costing This section discuss the fixed cost and variable cost of machine production. 8.4.1

Fixed Cost, CF Fixed cost is a cost that will not change with the increment of the production

amount. In this case, the production of machine involves machine cost as a fixed cost. The machine cost is used to buy the machine in production. The estimated machine cost is shown as follow: 𝐶𝑀 = 𝑅𝑀32,980 8.4.2

Variable Cost, CV Variable cost is the cost where it will increase with increment of production

output. In this project, labour cost, 𝐶𝐿 = 𝑅𝑀7,200, energy or electric cost, 𝐶𝐸 = 𝑅𝑀350, raw material cost, 𝐶𝑅 = 𝑅𝑀301,281.12 and technology cost, 𝐶𝑇 = 𝑅𝑀1,000 Considering 123 units of machine is produced. Total variable cost is 𝐶𝑣 = 𝑅𝑀309,831.12 Please refer to section 3.8.2 for bill of materials and cost 8.4.3

Total Cost, CT Total cost of producing one machine is the sum of fixed cost and variable cost

in production. Considering 123 units of machine is produced, the total cost is given by: 𝐶𝑇 = 𝐶𝐹 + 𝐶𝑉 𝐶𝑇 = 𝐶𝑀 + 𝐶𝐿 + 𝐶𝐸 + 𝐶𝑅 + 𝐶𝑇 𝐶𝑇 = 32,980 + 7,200 + 350 + 301,281.12 + 1,000 𝐶𝑇 = 𝑅𝑀342,811.12

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Figure 8.1: The relationship between total cost, fixed cost and variable cost. 8.4.4

Average Cost, CA Average cost is the total cost divided by number of machine produced. 𝐶𝐴 =

𝐶𝑇 𝑁

Where N=number of machine produced. 𝐶𝐴 =

342,811.12 123

𝐶𝐴 = 𝑅𝑀2,787.08 (RM 2,954.30 inclusive GST) 8.4.5 Manufacturing Productivity The manufacturing productivity is given by formula as follow: 𝑃=

𝑅𝑒𝑣𝑒𝑛𝑢𝑒 𝑓𝑟𝑜𝑚 𝑚𝑎𝑐ℎ𝑖𝑛𝑒 𝑀𝑎𝑛𝑢𝑓𝑎𝑐𝑡𝑢𝑟𝑖𝑛𝑔 𝑐𝑜𝑠𝑡

Considering 123 units of machine, and selling price of RM4000, total cost of RM342811.12: 𝑃=

4,000 × 123 342,811.12 𝑃 = 1.44

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8.4.5

Marginal Cost Table 8.1: Marginal Cost of the Production Production (Units) 10 20 30 40 50 60 70 80 90 100 110 120

Total Cost (RM) 30,580 64,180 96,380 127,280 156,980 185,580 214,180 240,880 267,780 292,980 317,530 341,530

Marginal Cost (RM) 0 3,460.00 3,320.00 3,190.00 3,070.00 2,960.00 2,860.00 2,770.00 2,690.00 2,620.00 2,555.00 2,500.00

Marginal Benefit (RM) 4,000 4,000 4,000 4,000 4,000 4,000 4,000 4,000 4,000 4,000 4,000 4,000

The marginal cost is the rate of change of production cost per unit of change of production. It could be denoted by the equation as follow: 𝑀𝑎𝑟𝑔𝑖𝑛𝑎𝑙 𝐶𝑜𝑠𝑡 =

𝑅𝑎𝑡𝑒 𝑜𝑓 𝐶ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝐶𝑜𝑠𝑡 𝑅𝑎𝑡𝑒 𝑜𝑓 𝐶ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝑃𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛

Taking the example from 10 to 20 units: 𝑀𝑎𝑟𝑔𝑖𝑛𝑎𝑙 𝐶𝑜𝑠𝑡 =

64,180 − 30,580 20 − 10

𝑀𝑎𝑟𝑔𝑖𝑛𝑎𝑙 𝑐𝑜𝑠𝑡 = 𝑅𝑀 3,460.00 Marginal benefit is the change of benefit when a unit of product is produced. In this case, the benefit would be the selling price of the machine, which is RM4,000/unit. 𝑀𝑎𝑟𝑔𝑖𝑛𝑎𝑙 𝐵𝑒𝑛𝑒𝑓𝑖𝑡 =

𝑅𝑎𝑡𝑒 𝑜𝑓 𝐶ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝐵𝑒𝑛𝑒𝑓𝑖𝑡 𝑅𝑎𝑡𝑒 𝑜𝑓 𝐶ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝑃𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛

Taking the example from 10 to 20 units: 𝑀𝑎𝑟𝑔𝑖𝑛𝑎𝑙 𝐵𝑒𝑛𝑒𝑓𝑖𝑡 =

80,000 − 40,000 10

𝑀𝑎𝑟𝑔𝑖𝑛𝑎𝑙 𝐵𝑒𝑛𝑒𝑓𝑖𝑡 = 𝑅𝑀 4,000

105

Note that the marginal cost is lower as the production increases. The marginal cost is always less than the marginal cost, this means that the production is economic and profitable. 8.5

Breakeven Analysis The breakeven analysis is intended to find the smallest production volume of

the EZ dryer in order to cover back the fixed cost, which is manufacturing machine cost in this case. The breakeven production volume could be calculated by the formula below: 𝑃 = (𝑆𝑃 − 𝐶𝑣 )𝑉 − 𝐶𝑓 Where Cf = fixed cost, Sp = selling price per unit of dryer, Cv = variable cost per unit of dryer, V = production volume and P is net profit. For calculating breakeven volume analysis, the minimum amount of dryer need to be sold in order to cover the fixed cost is determined. Consider the production in one month, and the Cv is estimated as RM 2,518.95, Sp=RM4,000 and Cf =RM32,980 𝑉=

𝑉=

𝐶𝑓 𝑆𝑃 − 𝐶𝑣

32,980 4,000 − (2,954.30) 𝑉 = 32 𝑢𝑛𝑖𝑡𝑠 Breakeven Cost, 𝐶𝐵 = 𝑉𝑆𝑃

𝐶𝐵 = 32 × 4,000 𝐶𝐵 = 𝑅𝑀128,000

106

8.6 Cost Benefit Analysis for Farmers Table 8.2: Summarise of Cost Benefit for Farmer Land

0.2 hectare

Production Benefit

2000 kg RM20/kg of dried berries RM40,000

Running time of pepper drying machine

4 month operating duration Total Electric consumption: RM782.32

Labour

RM 1,200 only one labour is required

Machine cost

RM 4,000

Cost

RM 5,982.32

Benefit

RM 40,000

Direct Sunlight Method Cost (Investment)

RM 10,000

Labour

RM 4,800 (4 labours is required)

Total Cost

RM 14,800

Benefit

RM 40,000

Cost Benefit Ratio

3

Method

E-Z Dryer

Traditional Method

Cost

RM 5,982.32

RM 14,800

Benefit

RM 40,000

RM 40,000

Benefit Cost Ratio

6.69

2.70

Benefit Cost Ratio is given by formula below 𝐵𝑒𝑛𝑒𝑓𝑖𝑡 𝐶𝑜𝑠𝑡 𝑅𝑎𝑡𝑖𝑜 =

𝐵𝑒𝑛𝑒𝑓𝑖𝑡 𝐶𝑜𝑠𝑡

(Equation 8.2)

Taking E-Z Dryer as example: 𝐵𝑒𝑛𝑒𝑓𝑖𝑡 𝐶𝑜𝑠𝑡 𝑅𝑎𝑡𝑖𝑜 =

40,000 5,982.32

𝐵𝑒𝑛𝑒𝑓𝑖𝑡 𝐶𝑜𝑠𝑡 𝑅𝑎𝑡𝑖𝑜 = 6.69 107

The benefit cost ratio of E-Z dryer is higher than that of traditional drying method, it indicates that E-Z dryer is a better as it provide more benefits to farmers in terms of income and savings in operating cost. 8.7 Net Present Value (NPV analysis for farmers) The price of machine is then decided to be RM 4,000 in one unit. The NPV analysis determine that whether the farmer is making profit if he is purchasing E-Z dryer. Net Present Value is the difference between the present value of cash inflow and cash outflow. The value becomes an indicator to determine whether an investment is profitable.

(Equation 8.3)

where Ct = net cash inflow during the period t Co = total initial investment costs r = discount rate, and t = number of time periods Table 8.3: NPV for the Farmer Year 0 1 2 3 4 5 6 7 8 9 10

Investment Cost (RM) RM3,000 RM 1,982.32 RM 1,982.32 RM 1,982.32 RM 1,982.32 RM 1,982.32 RM 1,982.32 RM 1,982.32 RM 1,982.32 RM 1,982.32 RM 1,982.32

Income (RM) 0 RM40,000.00 RM40,000.00 RM40,000.00 RM40,000.00 RM40,000.00 RM40,000.00 RM40,000.00 RM40,000.00 RM40,000.00 RM40,000.00 Total NPV

Cash Flow (10%) RM -3000 RM38,017.68 RM38,017.68 RM38,017.68 RM38,017.68 RM38,017.68 RM38,017.68 RM38,017.68 RM38,017.68 RM38,017.68 RM38,017.68 RM377,176.80 RM241117.48

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𝑁𝑃𝑉 = −3,000 +

38,017.68 38,017.68 38,017.68 38,017.68 38,017.68 + + + + 1 2 3 4 (1 + 0.10) (1 + 0.10) (1 + 0.10) (1 + 0.10) (1 + 0.10)5

+

38,017.68 38,017.68 38,017.68 38,017.68 38,017.68 + + + + 6 7 8 9 (1 + 0.10) (1 + 0.10) (1 + 0.10) (1 + 0.10) (1 + 0.10)10

𝑁𝑃𝑉 = −3000 + 34,561.53 + 31,419.57 + 28,563.25 + 25,966.59 + 23,605.99 + 21,459.99 + 19,509.08 + 17,735.53 + 16,123.21 + 14,657.46 𝑁𝑃𝑉 = +𝑅𝑀230,601.86 Since the NPV is positive, so the investment is profitable and sustainable, the farmer’s investment in E-Z dryer is profitable and sustainable in 10 years. From the cash flow, the payback period can be calculated as follow: 𝑃𝑎𝑦𝑏𝑎𝑐𝑘 𝑃𝑒𝑟𝑖𝑜𝑑 =

𝐼𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡 𝐶𝑎𝑠ℎ 𝑓𝑙𝑜𝑤

𝑃𝑎𝑦𝑏𝑎𝑐𝑘 𝑃𝑒𝑟𝑖𝑜𝑑 =

4,000 39,729

𝑃𝑎𝑦𝑏𝑎𝑐𝑘 𝑃𝑒𝑟𝑖𝑜𝑑 = 0.1 𝑦𝑒𝑎𝑟𝑠 8.8

Depreciation Rate Depreciation rate is the reduction of value of the dryer per year after the farmer

bought the machine. Assume that the depreciate 0.15% per year, and N=10 years machine life the salvage value, S becomes: 𝑆 = 𝑆𝑃 (1 − 0.15)𝑁 𝑆 = 4,000(1 − 0.15)10 𝑆 = 𝑅𝑀 787.50 So the depreciation rate, D: 𝐷=

𝐷=

𝑆𝑃 − 𝑆 𝑁

(Equation 8.4)

4,000 − 787.50 10

𝐷 = 𝑅𝑀321.25/𝑦𝑒𝑎𝑟 The main depreciated to RM 787.50 after 10 years with a value of RM321.25 each year. 109

8.9 Power Usage Cost EZ-Dryer is a hybrid solar dryer which can be used to reduce the electricity consumption. Assume that the dryer do not depend on the solar power monthly, and the heater operate for 8 hours per day, the total power consumption can be calculated as follow: The power of the heating coil, Ph = 1.5 kW. The power consumption per day in kWh can be expressed as: 𝑃𝑐 = 𝑃ℎ 𝐻

(Equation 8.5)

Where, operating hours = 8 hours 𝑃𝑐 = 1 𝑘𝑊 × 24ℎ 𝑃𝑐 = 24 𝑘𝑊ℎ In one month: 𝑃𝑚 = 24 𝑘𝑊ℎ/𝑑𝑎𝑦 × 30 𝑑𝑎𝑦𝑠 𝑃𝑚 = 720𝑘𝑊ℎ

Figure 8.2: Electrical pricing in commercial category. Adapted from: Sarawak Energy. 110

Total cost: 720 kWh x RM 0.315 = RM 226.8 From solar power: Useful solar power supplied is 3.304 kWh per day (4 hours sunlight irradiation). In one month 99.12 kWh energy is supplied from the sun. Total power usage 720 kWh – 99.12 kWh = 620.88 kWh 620.88 x 0.315 = RM 195.58 Annual Cost for 1 unit of EZ-Dryer = 195.58 x 4 =RM 782.32

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Conclusion

EZ-dryer is designed with the aim to increase the production rate and quality of pepper berries. The low cost of electricity (RM 195.58) consumption and yet provide an improvement percentage of 33.3% compared to conventional way of drying best suit the requirement of customer because it will not bring huge effect on the net profit of pepper berries. The procedures of designation are carried out based on product design specification and customer requirement, all the parameters are set according to precise analysis by utilizing the concept of material properties, mechanical strength of materials, mechatronics, ergonomics, thermofluids, simulation and modelling as well as safety precautions. Implementation of mechatronics reduce labour cost in long term, careful selection of materials ensures the lifespan of the machine, well-controlled temperature range ensure quality of pepper berries produced, economic analysis on EZ-dryer also incorporated the cost benefits due to improved quality, quicker drying higher yields and less floor area usage. In short, EZ-dryer tends to provide the best service to customers and lead to better quality in pepper berries production system.

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