Section A.docx

I-Hsiu Chiang H00239997

Section A: Main reactor design – H00239997 I-Hsiu Chiang

I-Hsiu Chiang H00239997

Introduction: Reactor This part of the report focuses on the storage of vinyl chloride and its conversion to polyvinyl chloride in the reactor. The task of this design is to produce 150 thousand tons of quality PVC annually, with the objective of making this process more efficient on energy usage and cost saving. Multiple reactors are used for this to make this process continuous, since it is a batch process known as suspension polymerization process. This allow for flexibility of maintaining and cleaning these reactors. The process in the reactor would produce a PVC slurry (a mixture of water and PVC) and unreacted vinyl chloride monomers (known as VCM) which would be further treated after being sent to the blown down drum and the stripper column. The inlet stream of initiator and additives are ignored, as this is a generalized PVC production. This report contains the mass and energy balance for all inlet and the outlet stream of the system, with the pump design and heat exchanger summarized in one aspect

I-Hsiu Chiang H00239997

Flow diagram of Reactor design and reactor setup

Figure 1: Flow diagram of reactor section

Valves are not displayed within the flow diagram, but the positions of each valves lie on every feed stream (so S-001, S-003, S-002, S-005) and all are consisting of fully opened ball valves. The equivalent length of those fittings is shown in table 30

VCM stream

Figure 2: General concept of VCM stream and reactor setup

I-Hsiu Chiang H00239997

Material Balance and process description Main assumptions The objective of this process is to make 150 thousand tons of PVC every year. There are numerous assumptions made for this material balanced. An example of this would be the single pass conversion of the reactor and the input of the initiator and additives. As this is a generalized process, this design would not be focus on the input of the initiator and additives, as there are a large range of different additives to make different types of PVC. It is decided that the single pass conversion for the reactor should be around 80%, as it ranges from 70~90% normally.[1] The temperature of the VCM is not affected by the pump when traveling to the reactor, hence there would be no temperature change when the liquid VCM is being pressurised. There would also be mass losses through each stream and it is assumed that the process is in a closed system. Table 1

Component S-001 S-002 S-003 S-004 S-005 S-006 VCM 22727.27 0 0 4545.454545 0 4545.5 H2O 0.00 0 27272.72727 0 0 27272.7 Additives 0.00 11.36363636 0 0 0 11.4 Initiator 0.00 0 0 0 22.7273 22.7 PVC 0.00 0 0 0 0 18181.8 Total 22727.27 11.36363636 27272.72727 4545.454545 22.7273 50034.1 Stream S-001 This stream is the one of the feed stream, which carries the liquid vinyl chloride monomers and mixes with stream S-003 before it enters the reactor. The heat exchangers heat up the VCM from -14C to 77C and the pumps increase the pressure from 1 atmosphere to 13 atmospheres. Stream S-002 Stream S-002 carries the additives to the reactor with the pump increase the pressure to 13 atmospheres. Because this process focuses on the general production of PVC, the additive is not specified in this process. To make this design more realistic, it is assumed that the 0.1% of additives are added based on the value of VCM inlet stream (S-001 multiplied by 0.1%). Stream S-003 Stream S-003 delivers a feed of deionised water to the reactor, with the same condition mentioned in stream S-001; 13 atmospheres and 77C. The purpose of deionised water is to create a PVC slurry for better transport of product through the pipeline and reduce the amount of impurities within the product of PVC. To make the PVC as a slurry the inlet of deionised water is 1.2 times more than the inlet of VCM. Stream S-004

I-Hsiu Chiang H00239997

This stream contains all the unreacted VCM that were transfer with the product PVC in S-006 and other streams. It only contains pure VCM therefore it is store back to the storage sphere to be reused again. Stream S-005 This is the initiator stream. Like Stream S-002, this part would not be focus on and it is assumed to have 22.7kg/h of flowrate, which is comparable to 0.05% mass of the inlet stream of VCM Stream S-006 This is the main product stream which PVC, VCM, water and some unreacted additives exits from the reactor. 4545 kg/hr of unreacted VCM passes through this stream, which occupies nearly 10% of the overall mixture, would mostly further be treated and recycled back to the VCM storage tank.

I-Hsiu Chiang H00239997

Energy balance Design assumptions The heat capacity of the VCM stream is calculated from an average of 2 temperature: -14 and 77 Celsius. The value of Cp is taken from the extrapolation of the graph below: Heat capacity of liquid VCM

Heat capacity of liquid VCM against temperature 0.35 y = 0.0007x + 0.2788

0.3

0.25 Heat capacity of liquid VCM

0.2

Cp (BtuIT lb-1 °F-1) 0.15

Linear (Heat capacity of liquid VCM)

0.1

0.05 0 -40

-20

0

20

40

60

Temperature (F)

Graph 1: Heat capacity of liquid VCM against temperature. Data taken from: Cameo chemicals (June 1999)

Using the equation of the trendline y = 0.0007x + 0.2788, the value of Cp can be taken as 0.28356 and 0.39822 BtuITlb-1°F-1. Converting these 2 values into kJ/kgK and it would be 1.1872 and 1.667 kJ/kgK. The average of these 2 values would be 1.4271 kJ/kgK (or 1.43 kJ/kgK). The energy balance shown below are calculated from the formula: 𝐻 = 𝑚𝐶𝑝 (𝑇2 − 𝑇𝑟𝑒𝑓 ) Where: T2 – temperature of the stream (K) Tref – reference temperature 298K Cp – heat capacity of the component in the stream (kJ/kgK) m – mass flowrate (kg/h)

(1)

I-Hsiu Chiang H00239997 Table 2

S002

S002.1

S003

S005

S-001 S-001.1 S-003.1 S-004 T (degree K) 259 350 298 298 298 350 335.00 298 P (bar) 1.05 13.17 1.05 13.17 1 13.17 - 1.05 Cp (kJ/kgK) 1.43 1.43 N/A N/A 4.184 4.184 0.86 N/A h (kJ/kg.s) -55.8 74.36 N/A N/A 0.00 217.568 31.79 N/A Total Q (kJ/h) 1267500 1690000 N/A N/A 0 5933673 144501.82 N/A

S005.1 S-006 298 13.17

335.00 10.00

N/A N/A

2.74 101.36

N/A

5071446.36

Since the value are extrapolated, the accuracy of both values is not guarantee, especially the heat capacity at 77 Celsius, due to being to far away from the maximum temperature of the measured heat capacity. The total power input for this process to work is calculated as 2500kW, which includes all the energy transfer from the heat exchanger and the power consumption of all the pumps together. Stream S-001.1 Stream S-001.1 features an increased in temperature from 259K to 350K after heat exchange taken place and the stream being pressurised by the pump. The amount of energy required for this process to take place is around 834.2kW, which also includes the power consumption from the pump. Stream S-002.1 This is the additive stream which is pressurised by the pump. No further calculation due to the generalisation of this process. Stream S-003.1 This stream is also shows an increased in temperature and pressure, same condition as Stream S-001.1. The energy calculated for this stream is 1666kW including the power consumed from the pumps. Stream S-005.1 This stream is just the pressurisation of organic initiator.

I-Hsiu Chiang H00239997

Heat exchangers design Heat exchanger design – Heat exchanger 1 (VCM stream) Due to the amount of energy required to heat up the VCM from -14 Celsius to 77 Celsius (the maximum temperature required), 2 heat exchangers would be applied for this process. The shell side fluid consists of water and the tube side consist of VCM. The heat exchanger in this case are act as a heater. Fluids properties for heat exchanger 1 (table 3) [2][3][4] Shell side Viscosity of water/ kg/sm Density of water/ kg/m3 Thermal conductivity of water/ W/m.C Specific heat/ kJ/kg°C Temperature/ °C

Inlet Mean Outlet 0.0003145 0.000477655 0.000641 965.4 978.655 991.91

Tube side Viscosity of VCM/ kg/sm Density of VCM/ kg/m3 Thermal conductivity of VCM/ W/m.C Specific heat/ kJ/kg°C Temperature/ °C

Inlet Mean Outlet 0.0005549 0.00049779 0.000441 957.60959 919.2327596 880.8559

0.6686998 0.646823893 0.624948 4.184 4.184 4.184 90 65.64935065 41.2987

0.1275562 0.120497458 0.113439 1.43 1.43 1.43 -14 13 40

For the shell side inlet temperature, it is decided that 90C of water would be enough for heating up the VCM up to 40C. Since the storage tank VCM temperature is largely different to the requirement temperature, 77C, therefore the first heat exchanger is heated up to 40C maximum. While lower inlet temperature can be used, it is better to use higher temperature due to the high value of pressure drop on the shell side would happen if flowrate of water on the shell side increases. Due to the difficulties to find heat capacity for vinyl chloride, the heat capacity for each component used for the heat exchangers are kept constant, since it would not change much in these conditions. Calculation The heat exchanger is calculated in number of steps (12 step to be exact), which the first step is to work out the duty (or the amount of energy) that are exchanged through between the shell side and the tube side. Therefore, to calculate this, this equation would be used: (2) Q = mCp ∆T The value of m is already given in the mass balance table, and both the temperature difference and Cp value of VCM is known, thus: 27272 Q= × 1.43 × (40 − −14) 3600 Q = +487.5kW

I-Hsiu Chiang H00239997

This value represents the amount of energy gain from the tube side fluid. To put this value in the shell side perspective, it would become: (3) Q = −487.5kW The mass flowrate for the shell side is set as 7kg/s and the heat capacity for water is 4.184. Hence by working backward based on the equation, the outlet temperature of the shell side can be calculated as:

I-Hsiu Chiang H00239997

−487.5 × 103 = 7 × 4.184 × (T − 100) T = 41.3 °C T = 41.3 °C The next step is to choose an trial overall coefficient, which it is estimated between 500 to 800W/m2C, but since the trial coefficient cannot be found from the table given from R&C for figure 12.2, the value is estimated around 500W/m2C. To understand the heat exchanger dimension and type of heat exchanger used, the log mean temperature should be worked out if the process is viable. (90 − 40) − (41.3 − −14) (4) ∆Tlm = = 52.6°C (90 − 40) ln ( ) (41.3 − −14) (90 − 41.3) (5) R= = 0.902 (40 − −14) (40 − −14) (6) = 0.519 (90 − −14) This graph is used to estimate the true mean temperature difference for most design. The temperature correction factor, Ft, for this design is estimated as 0.85. S=

Therefore, the mean temperature difference is: ∆Tm = 0.85 × 52.6 = 44.7°C The heat transfer area: 487.5 × 103 A= = 21.8m2 500 × 44.7

(7) (8)

I-Hsiu Chiang H00239997

There are a series of heat exchanger layout and sizes, which varies from 16 to 50mm outer diameter with thickness from 1.2 to 3.4, given in table 12.3 at p829: The dimension for this heat exchanger is 20mm outer diameter, 16mm inner diameter, 2.44m long tube on a triangular 25mm pitch. The original idea was to stick with 25mm pitch, but due to the very large value calculated for the pressure drop, the pitch was double, which is increased up to 50mm to compensate the pressure drop. Additional note: The reason that 2 heat exchangers is used is because the R and S value calculated for a single heat exchanger does not meet each other with the use of figure 12.19, therefore it was impossible to obtain a log mean temperature difference.

Number of tubes and tube side velocity (9) Area of one tube = π × 20 × 10−3 × 2.44 = 0.153m2 21.8 (10) Number of tubes = = 142 0.153 The number of tubes is round up to the whole number. The original plan for the number of passes was 2, but due to the slow tube side velocity, the number of passes is increased up to 4 so the velocity increases. Number of passes = 4 142 ∴ Tube per pass = = 36 4 π(0.016)2 (11) Cross section Area for each tube = = 0.000201062m2 4 Area per pass = 36 × 0.0002 = 0.007238m2 22727 0.0068678m3 (12) Volumetric flow = = 3600 × 919.233 s 0.0068678 (13) Tube side velocity, ut = = 0.9488 𝑚/𝑠 0.007238 This value is acceptable for later calculation for pressure drop Bundle and shell diameter From this table below, the value of K1 and n1 for 4 passes and triangular pitch is 0.175 and 2.285

1

142 2.285 Db = 20 ( ) = 375.17mm 0.175

(14)

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Based on the graph above, for a split-ring floating head heat exchanger, the shell clearance is roughly 55mm, so: Ds = 354.7 + 55 = 430.167mm

(15)

Tube-side heat transfer coefficient 919.233 × 0.9488 × 16 × 10−3 Re = = 28034 0.00049779 1.43 × 103 × 0.00049779 Pr = = 5.9075 1.306 L 2.44 = = 152.5 di 0.016

(16) (17) (18)

I-Hsiu Chiang H00239997

From figure 12.23, the heat transfer factor jn, based on the Reynolds number, is 0.0036 (19) Nu = 0.0036 × 28034 × 5.90750.33 = 181.364 0.120497 (20) hi = 181.364 ( ) = 1365.87 W/m2 C° 0.016 The original coefficient value is too low due to the low fluid velocity. The overall coefficient is about 500W/mC, therefore the number of passes is increased up to 4, so the velocity would double and the value of k1 and n1 would be 0.175 and 2.285: Shell side heat transfer coefficient Kern’s methods are applied here. The shell side would only have 2 passes, hence: 1

142 2.207 Db = 20 ( ) = 354.7mm 0.249 Clearance = 55m Ds = 354.7 + 55 = 409.7mm Ds (21) Baffle Spacing = = 82mm 5 The triangular pitch was originally 25mm and it is doubled after. This is due to the massive pressure drop value initially calculated. The increase in pitch significantly lower the pressure drop value to an acceptable amount. 50 − 16 (22) As = ( ) 409.7 × 82 = 0.020156m2 50 1.10 (23) de = ( ) 50.002 − 0.917 × 16.002 = 117.326mm 16.00 7 Volumetric flowrate = = 0.0071527m3 /s 978.655 0.0.071527 0.35m (24) Shell side velocity, us = = 0.020156 s

I-Hsiu Chiang H00239997

978.415 × 0.35 × 16 × 10−3 Re = = 84150.468 0.00049779 3 4.184 × 10 × 0.000477655 Pr = = 3.0897 0.646824 From the Re number, the jn is estimated as 0.0022 0.646824 hs = × 0.0022 × 84150.47 × 3.08970.33 = 1480.96 W/m2 C°(25) 117.325 × 10−3 Overall Coefficient Fouling factor tube side = 0.0002 Fouling factor shell side = 0.0002 20.00 −3 1 1 20.00 20 × 10 ln (16.00) 1 =( + 0.0002) + + + 0.0002 Uo 1366 16.00 2 × 55 1481 1 = 0.002080973 Uo Uo = 480.54 W/m2 C°

(26)

(27)

The value 55 is the thermal conductivity of stainless carbon steel. Using the calculated overall coefficient to compare the trial over coefficient, the difference is only by 3.89%, which can be concluded that it is quite accurate. Pressure Drop

Figure 3: Maximum allowable pressure drop

On page 844 in R&C, the allowable pressure drops for liquid that has the viscosity less than 1×10-3 Ns/m2 is 35kN/m2.

I-Hsiu Chiang H00239997

Tube side pressure drop

Friction factor jf is estimated to be around 0.0037 2440 919.233 × 0.94882 ∆Pt = 4 (8 × 0.0037 × + 2.5) = 11609Pa = 11.6kPa(28) 16.00 2 This value is within the value of 35kPa, therefore it is acceptable. Shell side pressure drop

Using figure 12.30 on page 857 of C&R, the friction factor at 25% baffle is 0.036

I-Hsiu Chiang H00239997

409.67 2440 978.665 × 0.354872 ∆Ps = 8 × 0.036 × ( )×( ) = 1843.9Pa 117.326 82 2 (29) = 1.84kPa The pressure shown above is the effect of increasing the pitch length.

I-Hsiu Chiang H00239997

Design specifications sheet for heat exchanger 1

Heat Exchanger Spec. Sheet

Equipment No. Function

H-01A

DUTY SPECIFICATIONS Overall U Area

481 21.81

Duty W/m2 K 2 Mean Temperature m PROCESS OPERATING CONDITIONS

487.50 339

kW K

Tube-Side Shell-Side IN OUT IN OUT Fluid Type Light organic Fluid Type Water Temperature 259 313 K Temperature 363 314.2987 K Mass Flow 6.31 kg/s Mass Flow 7.00 kg/s Enthalpy -55.77 74.36 kJ/kg Enthalpy 172.46 376.33 kJ/kg Density 958 881 Density 965 992 kg/m3 kg/m3 Viscosity 0.555 0.441 mN s/m 2 Viscosity 0.314 0.641 mN s/m 2 Thermal Conductivity 0.13 0.11 W/m K Thermal Conductivity 0.67 0.62 W/m K Specific Heat Capacity 1.43 1.43 kJ/kg K Specific Heat Capacity 4.18 4.18 kJ/kg K Molar Mass 62.498 kg/kmol Molar Mass 18.015 kg/kmol Stream No. S-001 S-001.1 Stream No. MECHANICAL LAYOUT Tube-Side Shell-Side Design Pressure 15 bar Design Pressure 15 bar No. of Tubes 142 No. of Passes 4 No. of Passes 2 Tube Arrangement Triangular Head Type Split-Ring Floating Head Pitch 0.050 m Baffle Type Segmental Internal Diameter 0.016 m Baffle Cut 25 % Outer Diameter 0.020 m Baffle Spacing 0.082 m Thickness 0.004 m Internal Diameter 0.410 m Length 2.44 m Fluid Velocity 0.9 m/s Fluid Velocity 0.4 m/s 2 1366 1481 Heat Transfer Coefficient Heat Transfer Coefficient W/m K W/m2 K 11.6 1.8 Pressure Drop bar Pressure Drop bar MATERIALS OF CONSTRUCTION Tube-Side Shell-Side Tube Material Carbon Stainless Steel Shell Material Carbon Stainless Steel 2 0.0002 0.0002 Fouling Factor Fouling Factor W/m K W/m2 K

I-Hsiu Chiang H00239997

Heat exchanger design – Heat exchanger 2 (VCM stream) The second heat exchanger is to heat up the VCM from 40 Celsius to 77 Celsius, which is the maximum temperature to produce PVC. The calculation for the heat exchanger 2 would be based on heat exchanger 1, although the number of passes remains. The triangular pitch is doubled, similar to the first heat exchanger. Fluid properties for heat exchanger 2 (table 4) [2][3][4] Shell side Viscosity of water/ kg/sm Density of water/ kg/m3 Thermal conductivity of water/ W/m.C Specific heat/ kJ/kg°C Temperature/ °C

Inlet Mean Outlet 0.0006409 0.000477655 0.000314 991.91 978.655 965.4 0.6573039 4.184 100

0.665843932 0.674384 4.184 4.184 87.02300786 74.04602

Tube side Inlet Mean Outlet Viscosity of VCM/ kg/sm 0.0004407 0.000412425 0.000384 Density of VCM/ kg/m3 880.85592 851.1373157 821.4187 Thermal conductivity of VCM/ W/m.C 0.1134387 0.109163316 0.104888 Specific heat/ kJ/kg°C 1.43 1.43 1.43 Temperature/ °C 40 58.5 77 The values above are all based the same sources as the heat exchanger 1. Trial overall coefficient = 500 W/m2 C° ∆Tlm = 28.16C° R = 0.7 S = 0.62 From the table shown above figure 12.19 ft = 0.75 ∴ ∆Tm = 21.1C° Heat exchanger 2 sizes, layout and required heat transfer area (table 5) Area required Outer D Inner D Triangular pitch length (value already doubled) Length of tube

31.62816991 m2 0.02 m 0.016 m 0.05 m 4.88 m

Number of tubes and tube side velocity (table 6) Area of one tube Number of tubes Number of passes Tube per pass

0.306619443 m2 103 tubes 2 52 tubes

I-Hsiu Chiang H00239997

Cross section A for tube Area per pass Volumetric flow for tube side Tube side velocity (ut)

0.000201062 0.01045522 0.007417289 0.709434004

m2 m2 m3/s m/s

Bundle and shell diameter (table 7) The number of passes is 2, therefore: K1 n1 Bundle Diameter DB Clearance (estimated, split-ring) Shell Diameter DS

0.249 2.207 306.6468152 mm 55 mm 361.6468152 mm

Tube side heat transfer coefficient (table 8) Re Pr L/di jh (estimated from figure 12.23 in C&R page 848) Nu hi

23425.39215 5.402615543 305 0.0031 126.7091287 864.4992903 W/m2C

Shell side heat transfer coefficient (table 9) K1 (table at right, triangular, 2 passes) n1 (table at right, triangular, 2 passes) Bundle Diameter Db Clearance DS Baffle Spacing (Ds/5) As Equivalent diameter de Volumetric flowrate (shell side) Shell side velocity Re Pr jn (estimated, figure 12.29 page 856) hs

0.249 2.207 306.6468152 55 361.6468152 73 0.015840131 117.326 0.009196295 0.580569391 137670.6508 3.001466898 0.0035 3930.136782

mm mm mm mm m2 mm m3/s m/s

W/m2C

Overall coefficient (table 10) Fouling factor tube side Fouling factor shell side 1/Uo Uo

0.0002 0.0002 0.002190939 456.4252397 W/m2C

I-Hsiu Chiang H00239997

The overall coefficient value calculated is only 8.71% away from the trial overall coefficient. It is therefore acceptable. Pressure drop (table 11) Tube side Re jf (friction factor) ΔPt in kPa

23425.39215 0.0045 5774.488566 Pa 5.774488566 kPa

Shell side Re 137670.6508 jf (friction factor) 0.041 ΔPs 11147.28434 Pa in kPa 11.14728434 kPa Again, the value shown above are below the requirement stated in C&R, therefore it is acceptable.

I-Hsiu Chiang H00239997

Design specification sheet for heat exchanger 2

Heat Exchanger Spec. Sheet

Equipment No. Function

H-01B

DUTY SPECIFICATIONS Overall U Area

456 31.63

Duty W/m2 K 2 Mean Temperature m PROCESS OPERATING CONDITIONS

334.03 360

kW K

Tube-Side Shell-Side IN OUT IN OUT Fluid Type Light organic Fluid Type Water Temperature 313 350 K Temperature 373 347.046 K Mass Flow 6.31 kg/s Mass Flow 9.00 kg/s Enthalpy -55.77 74.36 kJ/kg Enthalpy 417.5 309.26 kJ/kg 3 Density 881 821 Density 992 965 kg/m kg/m3 2 Viscosity 0.441 0.384 mN s/m Viscosity 0.641 0.314 mN s/m 2 Thermal Conductivity 0.11 0.10 W/m K Thermal Conductivity 0.66 0.67 W/m K Specific Heat Capacity 1.43 1.43 kJ/kg K Specific Heat Capacity 4.18 4.18 kJ/kg K Molar Mass 62.498 kg/kmol Molar Mass 18.015 kg/kmol Stream No. S-001 S-001.1 Stream No. MECHANICAL LAYOUT Tube-Side Shell-Side Design Pressure 15 bar Design Pressure 15 bar No. of Tubes 103 No. of Passes 2 No. of Passes 2 Tube Arrangement Triangular Head Type Split-Ring Floating Head Pitch 0.050 m Baffle Type Segmental Internal Diameter 0.016 m Baffle Cut 25 % Outer Diameter 0.020 m Baffle Spacing 0.073 m Thickness 0.004 m Internal Diameter 0.362 m Length 4.88 m Fluid Velocity 0.7 m/s Fluid Velocity 0.6 m/s 2 864 3930 Heat Transfer Coefficient Heat Transfer Coefficient W/m K W/m2 K 5.8 11.1 Pressure Drop bar Pressure Drop bar MATERIALS OF CONSTRUCTION Tube-Side Shell-Side Tube Material Carbon Stainless Steel Shell Material Carbon Stainless Steel 2 0.0002 0.0002 Fouling Factor Fouling Factor W/m K W/m2 K

I-Hsiu Chiang H00239997

Heat exchanger design – heat exchanger 3 (deionized water stream) The heat exchanger 3 are used to heat up the temperature of deionized water from 25 Celsius to 60 Celsius. The calculations are based off from the heat exchanger 2 and are used as template. Therefore, the pitch length is still doubled, with the number of passes remaining at 2. Fluid properties for heat exchanger 3 (table 12) [2][3][4] Shell side Viscosity of water/ kg/sm Density of water/ kg/m3 Thermal conductivity of water/ W/m.C Specific heat/ kJ/kg°C Temperature/ °C Tube side Viscosity of deionised water/ kg/sm Density of deionised water / kg/m3 Thermal conductivity of deionised water / W/m.C Specific heat/ kJ/kg°C Temperature/ °C

Inlet Mean 0.0002829 958.63 1.4543176 4.184 100 Inlet

Outlet 0.00035249 0.000422 969.285 979.94 1.376433007 4.184 83.4280303

Mean

Outlet

0.0008899

0.00067815

0.000466

997.05

990.12

983.19

1.1018342 1.184080306 4.184 4.184 25 42.5

1.266326 4.184 60

Trial value for overall coefficient Log mean temperature difference (Tlm) R S Ft (estimated) Mean temperature difference (Tm)

1000 W/m2C 40.92101508 °C 0.946969697 0.466666667 0.89 36.41970342 °C

Sizes, layout and heat transfer area of heat exchanger 3 (table 13) Area required Outer D Inner D Triangular pitch length Length of tube

30.46136666 0.02 0.016 0.05 4.88

m2 m m m m

Number of tubes and tube side velocity (table 14) Area of one tube Number of tubes Number of passes

1.298548 4.184 66.85606

0.306619443 m2 99 tubes 2

I-Hsiu Chiang H00239997

Tube per pass Cross section A for tube Area per pass Volumetric flow for tube side Tube side velocity (ut)

50 0.000201062 0.010053096 0.007651353 0.761094151

tubes m2 m2 m3/s m/s

Bundle and shell diameter (table 15) K1 n1 Bundle Diameter DB Clearance (estimated, split-ring) Shell Diameter DS

0.249 2.207 301.1925005 mm 55 mm 356.1925005 mm

Tube side heat transfer coefficient (table 16) Re Pr L/di jh (estimated) Nu hi

17779.53647 2.396272943 305 0.0031 73.54092734 5442.397734 W/m2C

Shell side heat transfer coefficient (table 17) K1 (table at right, triangular, 2 passes) n1 (table at right, triangular, 2 passes) Bundle Diameter Db Clearance DS Baffle Spacing (Ds/5) As Equivalent diameter de Volumetric flowrate (shell side) Shell side velocity Re Pr jn (estimated, figure 12.29 page 856) hs Overall coefficient (table 18)

0.249 2.207 301.1925005 55 356.1925005 72 0.015387516 117.326 0.008253506 0.53637679 171146.6712 1.071478344 0.0035 7189.386577

mm mm mm mm m2 mm m3/s m/s

W/m2C

I-Hsiu Chiang H00239997

Fouling factor tube side Fouling factor shell side 1/Uo Uo

0.0002 0.0002 0.000859344 1163.678802 W/m2C

Pressure drop (table 19) Re jf (friction factor) ΔPt In kPa

17779.53647 0.0045 7731.335051 Pa 7.731335051 kPa

Re jf (friction factor) ΔPs In kPa

171146.6712 0.041 9410.509256 Pa 9.410509256 kPa

Heat exchanger design – Heat exchanger 4 (deionized water stream) The second heat exchanger on the deionized water stream would be heating up the water from 60 Celsius to 77 Celsius Fluid properties of heat exchanger 4 (table 20) [2][3][4] Shell side Viscosity of water/ kg/sm Density of water/ kg/m3 Thermal conductivity of water/ W/m.C Specific heat/ kJ/kg°C Temperature/ °C

Inlet Mean Outlet 0.0002829 0.000332395 0.000382 958.63 966.985 975.34

Tube side Viscosity of deionised water/ kg/sm Density of deionised water/ kg/m3 Thermal conductivity of deionised water/ W/m.C Specific heat/ kJ/kg°C Temperature/ °C

Inlet

1.4543176 1.393790146 1.333263 4.184 4.184 4.184 100 87.12121212 74.24242 Mean

Outlet

0.0004664 0.000417215 0.000368 983.19

978.415

973.64

1.2663264 1.306274563 1.346223 4.184 4.184 4.184 60 68.5 77

Trial value for overall coefficient Log mean temperature difference (T LM)

1000 W/m2C 18.27277426 °C

I-Hsiu Chiang H00239997

R S Ft (estimated) Mean temperature difference (T M)

1.515151515 0.425 0.81 14.80094715 °C

Size, layout and heat transfer area (table 21) Area required Outer D Inner D Triangular pitch length Length of tube

36.40635152 0.02 0.016 0.05 4.88

m2 m m m m

Number of tubes and tube side velocity (table 22) Area of one tube Number of tubes Number of passes Tube per pass Cross section A for tube Area per pass Volumetric flow for tube side Tube side velocity (ut)

0.306619443 119 2 60 0.000201062 0.012063716 0.007742888 0.641832744

m2 tubes tubes m2 m2 m3/s m/s

Bundle and shell diameter (table 23) K1 n1 Bundle Diameter DB Clearance (estimated, split-ring) Shell Diameter DS

0.249 2.207 327.3802501 mm 55 mm 382.3802501 mm

Tube side heat transfer coefficient (table 24) Re Pr L/di jh (estimated) Nu hi

24082.69249 1.336340468 305 0.0031 82.15223511 6707.085937 W/m2C

Shell side heat transfer coefficient (table 25) K1 (table at right, triangular, 2 passes)

0.249

I-Hsiu Chiang H00239997

n1 (table at right, triangular, 2 passes) Bundle Diameter Db Clearance DS Baffle Spacing (Ds/5) As Equivalent diameter de Volumetric flowrate (shell side) Shell side velocity Re Pr jn (estimated, figure 12.29 page 856) hs

2.207 327.3802501 55 382.3802501 77 0.017665968 117.326 0.005170711 0.292693339 99038.40483 0.997812105 0.0035 4114.915297

mm mm mm mm m2 mm m3/s m/s

W/m2C

Overall coefficient (table 26) Fouling factor tube side Fouling factor shell side 1/Uo Uo

0.0002 0.0002 0.00091996 1087.003805 W/m2C

Pressure drop (table 27) Tube side Re jf (friction factor) ΔPt in kPa

24082.69249 0.0045 5433.213029 Pa 5.433213029 kPa

Shell side Re jf (friction factor) ΔPs in kPa

99038.40483 0.041 2806.205993 Pa 2.806205993 kPa

Both pressu1re loss value is less than 35kPa, therefore these values are acceptable.

5. R K Sinnott, Gavin Towler Ph.D. Dr. 2009. Coulson and Richardson Chemical Engineering Design, 12. Heat transfer equipment p.256-257, p.817-875. [Accessed on 19th March 2018]

I-Hsiu Chiang H00239997

Design specification for heat exchanger 3 and 4 (deionise stream)

Heat Exchanger Spec. Sheet

Equipment No. Function

H-08A

DUTY SPECIFICATIONS Overall U Area

935 30.46

Duty W/m2 K 2 Mean Temperature m PROCESS OPERATING CONDITIONS

1109.39 356

kW K

Tube-Side Shell-Side IN OUT IN OUT Fluid Type Water Fluid Type Water Temperature 298 333 K Temperature 373 339.8561 K Mass Flow 7.58 kg/s Mass Flow 8.00 kg/s Enthalpy 104.1 250.89 kJ/kg Enthalpy 417.5 279.45 kJ/kg 3 Density 997 983 Density 959 980 kg/m kg/m3 Viscosity 0.890 0.466 mN s/m 2 Viscosity 0.283 0.422 mN s/m 2 Thermal Conductivity 0.60 0.64 W/m K Thermal Conductivity 0.67 0.65 W/m K Specific Heat Capacity 4.18 4.18 kJ/kg K Specific Heat Capacity 4.18 4.18 kJ/kg K Molar Mass 18.015 kg/kmol Molar Mass 18.015 kg/kmol Stream No. S-003 S-003.1 Stream No. MECHANICAL LAYOUT Tube-Side Shell-Side Design Pressure 15 bar Design Pressure 15 bar No. of Tubes 99 No. of Passes 2 No. of Passes 2 Tube Arrangement Triangular Head Type Split-Ring Floating Head Pitch 0.050 m Baffle Type Segmental Internal Diameter 0.016 m Baffle Cut 25 % Outer Diameter 0.020 m Baffle Spacing 0.072 m Thickness 0.004 m Internal Diameter 0.356 m Length 4.88 m Fluid Velocity 0.8 m/s Fluid Velocity 0.5 m/s 2 3546 4406 Heat Transfer Coefficient Heat Transfer Coefficient W/m K W/m2 K 7.7 9.4 Pressure Drop bar Pressure Drop bar MATERIALS OF CONSTRUCTION Tube-Side Shell-Side Tube Material Carbon Stainless Steel Shell Material Carbon Stainless Steel 2 0.0002 0.0002 Fouling Factor Fouling Factor W/m K W/m2 K

I-Hsiu Chiang H00239997

Heat Exchanger Spec. Sheet

Equipment No. Function

H-08B

DUTY SPECIFICATIONS Overall U Area

843 36.41

Duty W/m2 K 2 Mean Temperature m PROCESS OPERATING CONDITIONS

538.85 360

kW K

Tube-Side Shell-Side IN OUT IN OUT Fluid Type Water Fluid Type Water Temperature 333 350 K Temperature 373 347.2424 K Mass Flow 7.58 kg/s Mass Flow 5.00 kg/s Enthalpy 250.89 321.99 kJ/kg Enthalpy 417.5 310.13 kJ/kg 3 Density 983 974 Density 959 975 kg/m kg/m3 Viscosity 0.466 0.368 mN s/m 2 Viscosity 0.283 0.382 mN s/m 2 Thermal Conductivity 0.64 0.66 W/m K Thermal Conductivity 0.67 0.66 W/m K Specific Heat Capacity 4.18 4.18 kJ/kg K Specific Heat Capacity 4.18 4.18 kJ/kg K Molar Mass 18.015 kg/kmol Molar Mass 18.015 kg/kmol Stream No. S-003 S-003.1 Stream No. MECHANICAL LAYOUT Tube-Side Shell-Side Design Pressure 15 bar Design Pressure 15 bar No. of Tubes 119 No. of Passes 2 No. of Passes 2 Tube Arrangement Triangular Head Type Split-Ring Floating Head Pitch 0.050 m Baffle Type Segmental Internal Diameter 0.016 m Baffle Cut 25 % Outer Diameter 0.020 m Baffle Spacing 0.077 m Thickness 0.004 m Internal Diameter 0.382 m Length 4.88 m Fluid Velocity 0.0 m/s Fluid Velocity 0.3 m/s 2 4212 2509 Heat Transfer Coefficient Heat Transfer Coefficient W/m K W/m2 K 5.4 2.8 Pressure Drop bar Pressure Drop bar MATERIALS OF CONSTRUCTION Tube-Side Shell-Side Tube Material Carbon Stainless Steel Shell Material Carbon Stainless Steel 2 0.0002 0.0002 Fouling Factor Fouling Factor W/m K W/m2 K

I-Hsiu Chiang H00239997

Pump design There would be 3 centrifugal pumps used in each of the 3 streams that enters the reactor to increase the pressure from 1 atm to 13 atm (VCM main stream, deionized water stream and additive stream), shown in the diagram below. The reason of introducing multiple pumps to the design is because the large total pump head calculated. It is also better to assume in a more realistic approach, as it is not possible for one pump to create such pressure starting from the atmospheric pressure. Centrifugal pumps are being used widely in industries, easier to maintain in many scenarios and compact which can save a lot of space. The original plan was to place these pumps after the heat exchanger to avoid further increase in pump head, but it is later found out that the vapour pressure significantly increased when the temperature increases, which affected the available NPSH hugely to the point of cavitation

Pump design – VCM stream Fluid properties (table 28) The process is isothermal, and the mass flowrate is kept constant. All the properties are calculated and operating at -14 Celsius. The pipe diameter is estimated to be 2 inch, as Fluid properties Mass flowrate Volumetric Flowrate Volumetric Flowrate in m3/s Pipe Diameter: Pipe Diameter in m: Density: Viscosity: Pump efficiency: Absolute Rough: galvanised iron Vapour pressure: Calculated Values Fanning (f) friction: Velocity: Cross Section A: Sigma (θ) friction: Reynold's: Relative Rough:

22727.27 24.947607 0.00692989 2 0.0508 911 0.00055493 57.5 0.015 408752

0.00273619 3.41907862 m/s 0.00202683 m2 0.0013681 285136.686 0.00029528

kg/h m3/h m3/s inch m kg/m3 Pa.s % mm Pa

I-Hsiu Chiang H00239997

Table 29: Absolute roughness of pipe materials. Taken from Process Engineering A

Fanning friction factor is known as: 2

1 𝑓=[ ] 𝑒 6.9 −1.8 ln [( ) + 𝑅𝑒 ] 3.7𝑑 𝑓 𝜑= 2

(30) (31)

Where: e- absolute roughness Re – Reynold’s number d – pipe diameter Substitute the values that is already known, therefore: 𝜌𝑢𝑑 911 × 3.419 × 0.0508 𝑅𝑒 = = = 285137 𝜇 0.0005549 2

1 𝑓=[ ] = 0.002736 0.015 × 10−3 6.9 −1.8 ln [( )+ ] 3.7 × 0.0508 285137 ∴𝜑=

𝑓 = 0.0013681 2

To calculate the velocity of liquid VCM in the pipeline it is necessary to determine the cross-section area of the pipe. 𝑑𝑖 2 𝐴= 𝜋× 2 Where: A is the cross-section area of pipe (m2) di is the pipe diameter (m) The area of pipe A was calculated to be 0.00203m2 𝑄 𝑢= 𝐴 Where u is the velocity of VCM (m/s) Q is the flowrate of VCM (m3/s) A is the internal area of the pipeline (m2)

(32)

(33)

I-Hsiu Chiang H00239997

The VCM velocity was calculated to be 3.419m/s

Centrifugal pump 1 Simplistic diagram of the centrifugal pumps displacement

Figure 4: Diagram of pumps in series

Suction head

Table 30: Equivalent length of fittings. Taken from Process Engineering A

To calculate total suction head, the following equation would be used: ℎ𝑓𝑠 𝑃𝑠 ℎ𝑠 = + ℎ𝑠1 + ℎ𝑠2 − 𝜌𝑔 𝜌𝑔 Where: hs1 – liquid level (suction vessel) hs2 – liquid level (suction vessel-pump) hfs – friction head loss (suction)

(34)

I-Hsiu Chiang H00239997

Ps/ρg – static pressure, where Ps is the static pressure which is at 1 atmosphere Before calculating the suction head, the friction head loss is required, which is written as: 𝐿𝑠𝑡 𝐿𝑠𝑒 (35) ℎ𝑓𝑠 = 4𝜑 ( + ) 𝜌𝑢2 𝑑 𝑑 Where: Lst – straight length of pipe, hs2 + Ls Lse – equivalent length (fittings), ƩLe The physical length of the pipe is assumed to be 5 meters and the assumed equivalent length would be 18 and 75, using table 1 above; 90-degree square elbow and a 100% opened ball valve would be placed at the suction head. Since the VCM storage tank is 40m tall, 36.5m would be the maximum liquid level of VCM. ∑ 𝐿𝑒 = (18 + 75)0.0508 = 4.7244𝑚 5 + 75 + 18 ℎ𝑓𝑠 = 4 × 0.0013681 ( ) × 911 × 3.4192 = 283.3647𝑃𝑎 0.0508 ℎ𝑠1 + ℎ𝑠2 = 5𝑚 101325 283.36 ℎ𝑠 = +5− = 47.81𝑚 911 × 9.81 911 × 9.81 Discharge head 1/ Suction head 2

(36) (37) (38) (39)

The equation used to calculate the discharge head is similar to the calculation done in the suction head. Due to multiple pump used, this section would be labelled as discharge head 1. The pressure was increased by a factor of 3 which is the maximum power to pressurize the stream for a general centrifugal pump. Hence the pressure has increased to 3 atmospheres. The distance between pumps is assumed to be 1m apart and there is no fitting in between the pumps, which suggest that there would be no equivalent length measured. The total physical length of the pipe starting from the first pump is 22 meters, so again, the pressure loss would be: 22 + 0 ℎ𝑓𝑠 = 4 × 0.0013681 ( ) × 911 × 3.4192 = 25239𝑃𝑎 = 25.2𝑘𝑃𝑎 (40) 0.0508 The total discharge head is calculated as: ℎ𝑓𝑑𝑖𝑠 𝑃𝑑𝑖𝑠.1 (41) ℎ𝑑𝑖𝑠.1 = + ℎ𝑑1 + ℎ𝑑2 + 𝜌𝑔 𝜌𝑔 303975 25239 ℎ𝑑𝑖𝑠.1 = + 15 + = 51.84𝑚 911 × 9.81 911 × 9.81 The total head for the first pump is therefore: (42) ℎ𝑡 = ℎ𝑑𝑖𝑠.1 − ℎ𝑠 = 51.8 − 47.8 = 4.03𝑚 Edit: It is later found out that the value of this head was not satisfactory, as there is hardly any pump that have such a low total pump head. Therefore, the pump diameter inlet is increased to 65mm and the outlet diameter remaining at 50mm. This change barely affects the pump head of the other pump, with the only value that affected is the total head of this pump, which decreased down to 3.42m. The power consumption for this pump is assumed to be:

I-Hsiu Chiang H00239997

911 × 9.81 × 4.03 × 0.00692989 × 1 × 10−3 = 0.434𝑘𝑊 (43) 57.5 ( 100 ) For the calculation above, it is assumed that the power efficiency would be roughly around 57.5% efficiency for this pump. The reason for this value is because 57.5% efficiency is obtained in both centrifugal pump 2 and 3, which would be shown later in this report. The power calculated showed that the amount of power consumed to compress from 1 atmosphere to 3 atmospheres is not very much. Power consumed =

NPSH (Net Positive Suction Head) The available NPSH would be required and compared with the required NPSH: 𝑃𝑠 − 𝑃 𝑠𝑎𝑡 𝐴𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒 𝑁𝑃𝑆𝐻 = + ℎ𝑠1 + ℎ𝑠2 + ℎ𝑓𝑠 𝜌𝑔 𝐴𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒 𝑁𝑃𝑆𝐻 =

(44)

101325 − 408752 283.3647 + 36.5 − = 2.07𝑚 911 × 9.81 911 × 9.81

The value of available NPSH above shows that the minimum required NPSH for the pumps should and must be greater than 2.07 meters. The available NPSH of other pump would not be calculated, as the values for the second and third pump is large due to the large friction pressure loss and the new static pressure.

I-Hsiu Chiang H00239997

Design specification of centrifugal pump 1 Project Name Project Number

Company Name: Heriot Watt University Edinburgh Address: Edinburgh, EH14 4AS

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DATE

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Pump and Line Calculation Sheet Form XXXXX-YY-ZZ

Case Description

Centrifugal pump used to pressurise vinyl chloride (VCM) and transfer from sphere storage tank to the reactor

Equipment label Plant section Fluid

P-01A A Liquified vinyl chloride

Equipment name

Operating temperature

Normal

77 ºC

Density

Min Max

77 ºC 77 ºC

Viscosity Normal flow rate Design flow rate

3 911 kg/m 2 0.000555 N.s/m 6.313131 kg/s 6.313131 kg/s

LINE PRESSURE DROP SUCTION Pipe Diameter Note u1 L1 e Quantity

Velocity

DISCHARGE 50.8

Normal Max. 3.4 3.4

Line length Absolute roughness Fittings L/d 1 Ball valve 100% 1 90 square elbow

mm Units m/s

5.00 L 18 75

0.9144 3.810

m

283.3647

Pa

101325

Pa

P fs

Pressure loss Total pressure loss

Pss

Static Pressure

Hs

Suction Head

47.8

Pi

Inlet Pressure

101325

NPSH available

m mm

0.015

Pipe Diameter Note u2

Flow Velocity

L2 e Quantity

Line length Absolute roughness Fittings Equipment Heat Exchanger (H-01) Pressure loss

m

2.068595

Pfd

Total pressure loss

m

Psd

Static Pressure

Pa

Hd

Discharge Head

Po

Outlet Pressure

50.8

mm

Normal Max. Units 3.4 3.4 m/s 22.00 0.015

m mm

L/d L Pressure loss -

Pa

25238.99

Pa

303975

Pa

m m

51.8

m

303975

Pa

m

PUMP DATA Pump manufacturer Catalog No. Pump flow rate

DAB water technology NKM-G series normal max.

Differential pressure

NPSH required Pump type No. of stages Impeller type

3

24.9 m /h

Shaft power Efficiency

0.434 kW 57.5 %

RPM

1450

Casing design pressure Casing design temperature

1160 kPa 140 ºC

3 24.9 m /h 202650 Pa

0.43 m Centrifugal pump 1 Closed, encased

Casing material

SKETCH

NOTES 1. The efficiency displayed is a rough estimate. Actual value ranges from 40~70%

CAST IRON 250 UNI ISO 185

APVD

I-Hsiu Chiang H00239997

Centrifugal pump 2 The fluid properties and the calculated values are the same to the previous pump, therefore it would not be display again. The value shown below are the suction and the discharge side of centrifugal pump 2 Table 31

Discharge Side/Suction Side 2 Static P: Liquid level (d): Physical Length (Length of pipes from pump 1 to the reactor): Equivalent Length: Friction P loss: Total discharge head:

303975 Pa 15 m 22 0 25238.9878 51.8375633

m m Pa m

Table 32 Discharge Side 2/Suction Side 3 Static P: Liquid level tank (Height of liquid above pump suction): Physical Length (Length of pipes from pump 1 to the reactor): Equivalent Length: Friction P loss: Total suction head: The total head from this pump is 57.7m

820732.5 Pa 15 m 21 0 24091.7611 109.532032

m m Pa m

I-Hsiu Chiang H00239997

Design specification of centrifugal pump 2 Project Name Project Number

Company Name: Heriot Watt University Edinburgh Address: Edinburgh, EH14 4AS

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DATE

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Pump and Line Calculation Sheet Form XXXXX-YY-ZZ

Case Description

Centrifugal pump used to pressurise vinyl chloride (VCM) and transfer from sphere storage tank to the reactor

Equipment label Plant section Fluid

P-01B A Liquified vinyl chloride

Equipment name

Operating temperature

Normal

77 ºC

Density

Min Max

77 ºC 77 ºC

Viscosity Normal flow rate Design flow rate

3 911 kg/m 2 0.000555 N.s/m 6.313131 kg/s 6.313131 kg/s

LINE PRESSURE DROP SUCTION Pipe Diameter

DISCHARGE 50.8

Note u1

Velocity

Normal Max. 3.4 3.4

L1 e Quantity -

Line length 22.00 Absolute roughness Fittings L/d L -

P fs

Pressure loss Total pressure loss

Pss

Static Pressure

Hs

Suction Head

51.8

Pi

Inlet Pressure

303975

NPSH available

mm Units m/s m mm

0.015

Pipe Diameter Note u2

Flow Velocity

L2 e Quantity

Line length Absolute roughness Fittings Equipment Pressure loss

m m

25238.99

Pa

303975

Pa

2.068595

Pfd

Total pressure loss

m

Psd

Static Pressure

Pa

Hd

Discharge Head

Po

Outlet Pressure

50.8

mm

Normal Max. Units 3.4 3.4 m/s 21.00 0.015

m mm

L/d L Pressure loss -

m m

24091.76

Pa

820733

Pa

109.5

m

820733

Pa

m

PUMP DATA Pump manufacturer Catalog No. Pump flow rate

DAB water technology NKP-G series normal max.

Differential pressure

NPSH required Pump type No. of stages Impeller type

3

24.9 m /h

Shaft power Efficiency

6.214 kW 57.5 %

RPM

1450

Casing design pressure Casing design temperature

1160 kPa 140 ºC

3 24.9 m /h 516758 Pa

2m Centrifugal pump

Casing material 1

Closed, encased

SKETCH

NOTES 1. The efficiency displayed is a rough estimate. Actual value ranges from 40~70%

CAST IRON 250 UNI ISO 185

APVD

I-Hsiu Chiang H00239997

Centrifugal pump 3 Table 33 Discharge Side 2/Suction Side 3 Static P: Liquid level tank (Height of liquid above pump suction): Physical Length (Length of pipes from pump 1 to the reactor): Equivalent Length: Friction P loss: Total suction head:

820732.5 Pa 15 m 21 0 24091.7611 109.532032

m m Pa m

Table 34 Discharge Side 3 Discharge static P: Liquid level tank (Height of liquid above pump suction): Physical Length (Length of pipes from pump 1 to the reactor): Equivelant Length: Friction P loss: Total suction head: The total head from this pump is 56.2m

1317225 Pa 15 m 20 9.144 33434.7754 166.132749

m m Pa m

Total pump head from the series 118.3266448 m The total power consumed in this stream is 12.7kW

I-Hsiu Chiang H00239997

Design specification for centrifugal pump 3

Project Name Project Number

Company Name: Heriot Watt University Edinburgh Address: Edinburgh, EH14 4AS

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DATE

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1

REV

of

1

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Pump and Line Calculation Sheet Form XXXXX-YY-ZZ

Case Description

Centrifugal pump used to pressurise vinyl chloride (VCM) and transfer from sphere storage tank to the reactor

Equipment label Plant section Fluid

P-01C A Liquified vinyl chloride

Equipment name

Operating temperature

Normal

77 ºC

Density

Min Max

77 ºC 77 ºC

Viscosity Normal flow rate Design flow rate

3 911 kg/m 2 0.000555 N.s/m 6.313131 kg/s 6.313131 kg/s

LINE PRESSURE DROP SUCTION Pipe Diameter

DISCHARGE 50.8

Note u1

Velocity

Normal Max. 3.4 3.4

L1 e Quantity -

Line length 21.00 Absolute roughness Fittings L/d L -

P fs

Pressure loss Total pressure loss

Pss

Static Pressure

Hs

Suction Head

Pi

Inlet Pressure NPSH available

mm Units m/s

0.015

m mm

Pipe Diameter Note u2 L2 e Quantity

m m

Flow Velocity Line length Absolute roughness Fittings 3 90 degree standard elbow 1 Entry into T leg-piece Equipment Heat Exchanger (H-01) Pressure loss

25238.99

Pa Pfd

Total pressure loss

303975

Pa

51.8

m

Psd

Static Pressure

303975

Pa

Hd

Discharge Head

Po

Outlet Pressure

2.068595

50.8

mm

Normal Max. Units 3.4 3.4 m/s 20.00 0.015

m mm

L/d

L 90 4.572 90 4.572 Pressure loss 17383

m m Pa

50818

Pa

1317225

Pa

166.1

m

1317225

Pa

m

PUMP DATA Pump manufacturer Catalog No.

DAB water technology NKP-G series

Pump flow rate

normal max.

Differential pressure

NPSH required Pump type No. of stages Impeller type

3 24.9 m /h

Shaft power Efficiency

6.623 kW 57.5 %

RPM

2900

Casing design pressure Casing design temperature

1160 kPa 140 ºC

3 24.9 m /h 1013250 Pa

2m Centrifugal pump

Casing material 1

Closed, encased

SKETCH

NOTES 1. The efficiency displayed is a rough estimate. Actual value ranges from 40~70%

CAST IRON 250 UNI ISO 185

APVD

I-Hsiu Chiang H00239997

Pump design – deionised water stream Again, there would be 3 centrifugal pumps used for the deionised stream to increase the pressure up to 13 atmospheres. Large pump head is also acknowledged in this stream therefore multiple pumps would be used again. The calculation methods are all based on the previous section. Table 35 Fluid properties Mass flowrate Volumetric Flowrate Volumetric Flowrate in m3/s Pipe Diameter: Pipe Diameter in m: Density: deionised water Viscosity: deionised water Pump efficiency: Absolute Rough: galvanised iron Vapour pressure: Calculated Values Fanning (f) friction: Velocity: Cross Section A: Sigma (θ) friction: Reynold's: Relative Rough: Centrifugal pump 1

27272.7273 28.0110999 0.00778086 2 0.0508 973.64 0.00036806 57.5 0.015 41797.4643

kg/h m3/h m3/s inch m kg/m3 Pa.s % mm Pa

0.00245747 3.83893143 m/s 0.00202683 m2 0.00122874 515886.132 0.00029528

Table 36 Suction Side Suction static P: Liquid level tank (Height of liquid above pump suction): Physical Length (Length of pipes): Equivelant Length: Friction P loss: Total suction head: Table 37 Discharge Side/Suction Side 2 Static P: Liquid level (d): Physical Length (Length of pipes from pump 1 to the reactor): Equivelant Length:

101325 Pa 0 5 4.7244 342.9025 10.57248

m m m Pa m

303975 Pa 15 m 22 m 0 m

I-Hsiu Chiang H00239997

Friction P loss: Total discharge head:

30541.95 Pa 50.02279 m

Centrifugal pump 2 Table 38 Discharge Side/Suction Side 2 Static P: Liquid level (d): Physical Length (Length of pipes from pump 1 to the reactor): Equivelant Length: Friction P loss: Total discharge head:

303975 Pa 15 m 22 0 30541.95 50.02279

m m Pa m

Table 39 Discharge Side 2/Suction Side 3 Static P: Liquid level tank (Height of liquid above pump suction): Physical Length (Length of pipes from pump 1 to the reactor): Equivelant Length: Friction P loss: Total suction head:

820732.5 Pa 15 m 21 0 29153.68 97.87561

m m Pa m

Centrifugal pump 3 Table 40 Discharge Side 2/Suction Side 3 Static P: Liquid level tank (Height of liquid above pump suction): Physical Length (Length of pipes from pump 1 to the reactor): Equivelant Length: Friction P loss: Total suction head: Table 41

820732.5 Pa 15 m 21 0 29153.68 97.87561

m m Pa m

I-Hsiu Chiang H00239997

Discharge Side 3 Discharge static P: Liquid level tank (Height of liquid above pump suction): Physical Length (Length of pipes from pump 1 to the reactor): Equivelant Length: Friction P loss: Total suction head:

1317225 Pa 15 m 20 8.5344 39613.465 148.761586

m m Pa m

The total power consumed for these 3 pumps is 17.9kW and the total head produced from all these 3 pumps together is equ2al to 138.2m

6. Heriot- Watt University Edinburgh, June 2015. TOPIC 4. PUMP SYSTEMS and PUMP SIZING, B48BB Process Engineering A Student Guide. p.24-28. [Access on 18th March 2018]. 7. Dab water technology, 2015. NKM-G / NKP-G – STANDARDISED MONOBLOC CENTRIFUGAL ELECTRIC PUMPS

I-Hsiu Chiang H00239997

Design specification of centrifugal pumps (deionised water) This design specification merges all values of 3 pumps together Project Name Project Number

Company Name: Heriot Watt University Edinburgh Address: Edinburgh, EH14 4AS

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Pump and Line Calculation Sheet Form XXXXX-YY-ZZ

Case Description

Centrifugal pump used to pressurise water and transfer to the reactor

Equipment label Plant section Fluid

P-03 A Deionised water

Operating temperature

Normal

77 ºC

Density

Min Max

77 ºC 77 ºC

Viscosity Normal flow rate Design flow rate

Equipment name

3 973.64 kg/m 2 0.000368 N.s/m 7.575758 kg/s 7.575758 kg/s

LINE PRESSURE DROP SUCTION Pipe Diameter Note u1 L1 e Quantity

Velocity

DISCHARGE 50.8

Normal Max. 3.8 3.8

Line length Absolute roughness Fittings L/d 1 Ball valve 100% 1 90 square elbow

P fs

Pressure loss Total pressure loss

Pss

Static Pressure

Hs

Suction Head

Pi

Inlet Pressure

mm Units m/s

5.00

NPSH available

0.015

m mm

L 18 75

0.9144 3.810

Note u2 L2 e Quantity

m m

342.9025

Pa

101325

Pa

10.6

m

101325

Pa

6.19643

Pipe Diameter

m

Pfd

Flow Velocity Line length Absolute roughness Fittings 1 Entry into T leg-piece 1 Entry from T leg-piece 1 Ball valve 100% Equipment Heat Exchanger Pressure loss Total pressure loss

Psd

Static Pressure

Hd

Discharge Head

Po

Outlet Pressure

50.8

mm

Normal Max. Units 3.8 3.8 m/s 22.00 0.015 L/d

m mm

L 90 60

18

m m

4.572 3.048 0.9144

m

Pressure loss 13165

Pa

52778

Pa

1317225

Pa

148.8

m

1317225

Pa

PUMP DATA Pump manufacturer Catalog No.

DAB water technology NKM-G series

Pump flow rate

normal max.

Differential pressure

NPSH required Pump type No. of stages Impeller type

3 28.0 m /h

Shaft power Efficiency

17.861 kW 57.5 %

RPM

1450

Casing design pressure Casing design temperature

1160 kPa 140 ºC

3 28.0 m /h 1215900 Pa

2m Centrifugal pump

Casing material 1

Closed, encased

SKETCH

NOTES 1. The efficiency displayed is a rough estimate. Actual value ranges from 40~70%

CAST IRON 250 UNI ISO 185

APVD

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Mechanical Calculations Valves: Ball valve [9] For each inlet stream, as stated in figure 1, there would be a ball valve place for the stream so that the flow can be controlled manually. Due to the high flowrate, the valve chosen can withstand high level of pressurised environment. The inlet and outlet diameter ranged from a quarter of an inch to 3 inches. The reason for choosing such a ball valve for this process is because it is much safer and has a higher life expectancy due to its maximum working pressure. It also reduces cost for the long run. Specifications Attribute Threaded Connection Attachment Type Body Material Thread Size Safe for Use With Maximum Working Pressure Connection Size mm Connection Size inch Handle Colour Ball Material Maximum Working Pressure bar Thread Standard Maximum Working Pressure psi Handle Material Type Handle Type

Value 1/2 in BSPP Threaded Stainless Steel 1/2in Gas, Oil, Water 68 bars 15mm 1/2in Blue Stainless Steel 63bar BSPP 580psi Stainless Steel 2 Way Lever

Figure 5: Diagram and sketch of ball valve

Pipe wall thickness [5][8] The wall thickness calculation of the pipe was used as a measure for resistance against internal pressure and for damages such as corrosion and erosion. This calculation is followed by the standard set by the ASME (American Society of Mechanical Engineers) and many chemical plants and oil refinery pipework companies. The ASME B31.3 code calculate pipe thickness as: 𝑡𝑚 = 𝑡𝑝 + 𝑐 𝑡𝑝 = Where:

𝑃𝑑 2(𝑆𝐸 + 𝑃𝛾)

(45) (46)

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tm is the minimum required thickness tp is the pressure design thickness c is the sum of mechanical allowances plus corrosion and erosion allowances P is the internal design pressure (N/mm2) d is the outer pipe diameter S is the basic allowable stress for carbon (N/mm2) and γ is the temperature coefficient Due to the lack of information of these constants, the nominal wall thickness taken from ANSI B36.10 would be used instead, which present the wall thickness required for this process should be 0.154 inch for 2 inch nominal sized pipe. Corrosion allowance Corrosion allowance is the additional thickness of metal added to compensate the lost material of pipe by corrosion and erosion from fluids. There are no specific rules for estimation for corrosion allowance for pipe designs and most design were based on experiences from people who has worked on specific pipe material for many years. For carbon and low alloyed steels, it is recommended that the minimum allowance for the pipe should be not be less than 2mm. But since some pipes is working under severe conditions in this process (such as the pipe that delivers the VCM to the reactor under the pressure of 13 atmosphere), it is also recommended that the thickness increases to 4mm. Under the European standard BS EN-13445-3, it states ‘an additional thickness sufficient for the design life of the vessel components shall be provided’. (C&R p1003)

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Safety and environment [10] [11] The main hazards of the process lie within the storage of VCM and process condition in the reactor. Large quantities of pressurised VCM creates a significant risk of an explosion or a leakage if it is not managed and maintained properly. Hence it is important that offices are allocated in a safe displacement and conditions of VCM storage to be managed properly. The storage sphere and the reactor should be positioned with a certain distance away from the control rooms and offices where if a fire or explosion happens, workers on site would be able to evacuate the facility as fast as possible to minimise risk. Implementation of fireproof and explosion-proof materials should be used and surrounds the places where there is a likelihood of explosion and gas leak, in which this includes the reactor and its pipelines due to the high pressurised condition. There are sensors that are placed around the reactor to detect leakages of materials from each vessels and components which can alert the employees on site if certain level of risk has been reach, such as the level of VCM vapour cloud form or abnormal temperature in reactor and pipelines. These alarm systems are also frequently checked each week to make sure its functionality. The faulty sensors that are detected by site workers should straight away report this to the company and immediately replaced the sensor to avoid more risks. Vinyl chloride is a colourless gas and exposure to VCM can lead to increased risks of a rare form of liver cancer called angiosarcoma, and possible increased risks of hepatocellular carcinomas. VCM is classified as a Group 1 carcinogen by IARC, and as Category 1 carcinogen in the EU under the classification and labelling legislation. The substance is also known to be extremely flammable and gives off irritating or toxic fumes in a fire. It is suggested that the workers should have no access to open flames and sparks in these area and smoking is not allowed. Mixing VCM with air can cause explosion which can be prevented with a closed system and ventilation, explosion-proof electrical equipment and lighting. Hand tools are restricted to non-sparking. Inhalation can lead to dizziness, drowsiness, headache and unconsciousness and frostbite would occur if it is in contact with skin. To prevent high dosage from inhalation, site workers are told to wear all protective clothing around the body at facilities where there is a likelihood of high level of VCM. To further lower the risk, all workers must go through thorough training of precautions and given adequate PPE to ensure health and safety on site is met. The effect this process has on the environment is almost none existence, due to large quantities of vinyl chloride are recycled back into the process or it is in a very close system with well protected vessels due to its toxicity. This means that there are only very few major waste products. This process would be located at a pre-existing site where there is access to raw materials from other site processes.

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Conclusion The reactor units are the main source of PVC production which is further treated in later processes in the blow down drum (See section B). While it can be said that the mass balance and the energy balance are acceptable, there are also many values that are unknown, such as the composition of initiator and additive which the task did not specify the type of PVC, only the production rate as a target. The approach for the pump design are much more realistic, as it was told and recommended that the pump can only increase by a maximum factor of 3, hence, multiple pumps are used in the process. By applying this method, it does lead to an enormous amount of calculations, which the calculations and values for each pump and heat exchanger is later summarized in tables. There was a lack of information for the calculation of the wall thickness and corrosion allowance, but suggestions from organization such as European Standard, which it suggest additional thickness for compensation. Lastly, according to most health and safety organization in EU, VCM monomers are classified as a carcinogenic substance, with many risks of injuries if in contact with air, skin and inhalations. PPE should be provided, and staff are required to be trained thoroughly to minimized risk exposure.

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Reference 1. G. Butters. 1982. Particulate Nature of PVC: Formation, Structure and Processing – Particle formation. p.24. Publisher: Applied Science. [Access on 1st March 2018] 2. NIST, 2017. Thermophysical Properties of Fluid Systems. Available at: https://webbook.nist.gov/chemistry/fluid/ [Access on 2th March 2018] 3. Yaws, Carl L. (2010). Yaws' Critical Property Data for Chemical Engineers and Chemists - Density of Liquid – Organic Compounds. Publisher: Knovel. p.135. [Access on 28th March 2018] 4. Yaws, Carl L. (2012). Yaws' Thermophysical Properties of Chemicals and Hydrocarbons - Viscosity of Liquid – Organic Compounds p.133, Thermal Conductivity of Liquid – Organic Compounds p.391. Publisher: Knovel. [Access on 5th March 2018] 5. R K Sinnott, Gavin Towler Ph.D. Dr. 2009. Coulson and Richardson Chemical Engineering Design, 12. Heat transfer equipment p.256-257, p.817-875. [Accessed on 19th March 2018] 6. Heriot- Watt University Edinburgh, June 2015. TOPIC 4. PUMP SYSTEMS and PUMP SIZING, B48BB Process Engineering A Student Guide. p.24-28. [Access on 18th March 2018] 7. Dab water technology, 2015. NKM-G / NKP-G – STANDARDISED MONOBLOC CENTRIFUGAL ELECTRIC PUMPS - NKP-G 32-200. p.79. Publisher: DAB PUMPS. [Access on 1st April 2018] 8. Engineering ToolBox, (2008). Pipes - Nominal Wall Thickness. Available at: https://www.engineeringtoolbox.com/nominal-wall-thickness-piped_1337.html. [Access on 1st April 2018] 9. RS components. 2016. RS Pro High Pressure Ball Valve Stainless Steel 1/2 in BSPP 2 Way – specification. Available at: https://uk.rsonline.com/web/p/manual-ball-valves/4992795/. [Access on 6st April 2018] 10. Europe Commission, 2016. 5.11 Vinyl chloride monomer. p.70. Available at: https://ec.europa.eu/transparency/regdoc/rep/10102/2016/EN/SWD-2016152-F1-EN-MAIN-PART-1.PDF. [Access on 1st April 2018] 11. Centers for Disease Control and Prevention. April 2000. VINYL CHLORIDE. Available at: https://www.cdc.gov/niosh/ipcsneng/neng0082.html. [Access on 1st April 2018]