A. Higher condensing film co-efficient is desired
B. Condensate is corrosive in nature
C. Lower pressure drop through the exchanger is desired
D. Temperature of the incoming vapor is very high
Related Mcqs:
- Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is________________?
A. Finned tube heat exchanger with air inside and steam outside
B. Finned tube heat exchanger with air outside and steam inside
C. Shell and tube heat exchanger with air inside tubes and steam on shell side
D. Shell and tube heat exchanger with air on shell side and steam inside tubes - Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient for the cooling water, whether on shell side or tube side is the same. The best arrangement is_____________?
A. Vertical heat exchanger with steam on tube side
B. Vertical heat exchanger with steam on shell side
C. Horizontal heat exchanger with steam on tube side
D. Horizontal heat exchanger with steam on shell side - The inside heat transfer co-efficient in case of turbulent flow of liquid in the tube side in a 1-2 shell and tube heat exchanger is increased by ______________ times, when the number of tube passes is increased to 8?
A. 20.8
B. 40.8
C. 40.4
D. 20.4 - The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is___________________?
A. More
B. Less
C. Some
D. Either more or less; depends on the nature of vapor - If air (a non-condensing gas) is present in a condensing vapor stream, it will ______________ the condensation rate of vapor?
A. Increase
B. Decrease
C. Not affect
D. Increase the condensing film co-efficient as well as - In a shell and tube heat exchanger, putting a longitudinal baffle across the shell, forces the shell side fluid to pass _____________ through the heat exchanger ?
A. Once
B. Twice
C. Thrice
D. Four times - The advantage of using a 1 – 2 shell and tube heat exchanger over a 1 – 1 shell and tube heat exchanger is_________________?
A. Lower tube side pressure drop
B. Lower shell side pressure drop
C. Higher tube side heat transfer co-efficient
D. Higher shell side heat transfer co-efficient - A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m2.°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be__________________?
A. Greater than that for un-insulated steam pipe
B. Less than that of the un-insulated steam pipe
C. Equal to that of the un-insulated steam pipe
D. Less than the steam pipe with 5 cms insulation - In a shell and tube heat exchanger, the tube side heat transfer co-efficient just at the entrance of the tube is_________________?
A. Infinity
B. Zero
C. Same as average heat transfer co-efficient for tube side
D. None of these - In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will___________________?
A. Increase
B. Decrease
C. Remain unchanged
D. Either increase or decrease; depends on the coolant flow rate
