Me Lab 6.docx

University of Southern Philippines Foundation Salinas Drive, Lahug, Cebu Ciity College of Engineering and Architecture ME422 Lab2 Name: Earon Jay S. Cadungog Course: BSME-4

Report no. 6 Date:

Test of Tubular Condenser Theory: The capacity of the tubular heat exchanger may be expressed in terms of the amount of steam condensed per unit time which is dependent upon the conditions of the cooling water supplied. The maximum capacity, however, can be considered as the amount of steam condensed when an infinite flow rate of cooling water is supplied. This also means that there is practically no heat transfer resistance in the cooling water side such that its temperature throughout the operation remains constant. Objectives: 1. To determine the capacity of the tubular condenser as a function of the flow rate of the cooling water used. 2. To determine the experimental overall heat transfer coefficient for a vertical tubular condenser. 3. To calculate theoretical surface coefficients of steam condensing inside the tubes and of the cooling water flowing upwards the shell side of the condenser. 4. To compare experimental and theoretical values of the overall heat transfer coefficients as obtained in (2) and (3). 5. To determine the heat lost to the surroundings. Apparatus: Tubular Head Condenser

Procedure: 1. Drain the residual steam condensate by opening the drain valve. 2. Allow cooling water to flow through the condenser by opening fully the water supply valves. 3. Stabilize the equipment by allowing small amount of steam inside to escape (this will also remove residual condensate). Close the drain valve and make sure that the condensate line with the steam trap is fully open. Then increase pressure to the desired level (say 30 psig). Allow equipment to heat to a stable temperature. Read temperature occasionally until the system has reached an almost steady state condition. The condensate collected must already be clean. 4. Operate the system for about 10 to 15 minutes at constant steam pressure. Within this interval determine temperature and pressure readings, flow rates of condensate and cooling water used. Note that the condensate collection tank has a gauge for direct reading of mass collected. Since the amount of condensate is usually small, it is suggested that one measures the total condensate collected within the time interval of the run. For the cooling water, (used as the hot fluid in the experiment involving double pipe heat exchanger), the flow rate is measured in the collection tank 5. Repeat the procedure making use of various water flow rates and various steam pressures. The water pressure gauge may be used as a guide in varying the water flow rate. It is suggested that three different steam pressures (say 30, 40, & 50 psig) and three water flow rates for a total of nine runs be conducted to complete the experiment. Findings: The steam enters the bottom of the condenser through the header then rises inside the tubes where the steam condenses on the inside surface of the tubes. The condensate flows downwards as thin film and collects at the bottom where it is discharged through the steam trap then to the condensate collection tank. Observation: The cooling water is introduced at the bottom of the shell and rises outside the bundle of tubes and exits on top, flows through the double pipe heat exchanger and is discharged to the hot water collection tank. This tank gives a direct reading in pounds of water. Conclusion: The equipment used for this experiment is a vertical tube condenser. The tubular condenser has 38 tubes within the shell. These tubes are 85 inches long and made of steel. Consequently, the tubes have outside diameters of 18 mm or 0.7086 inch. The inside diameter of these tubes are 0.4375 inch each.