A. Steam
B. Condensate
C. Non-condensable
D. None of these
Related Mcqs:
- 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 - Steam trap is used to_________________?
A. Condense the steam flowing in the pipeline
B. Remove water resulting from partial condensation of steam
C. Stop the supply of steam
D. None of these - The maximum heat transfer co-efficient from steam heating will be attained when the steam is_________________?
A. Supersaturated
B. Saturated
C. Wet
D. None of these - Steam condensate is recovered by steam traps and recycled for use as boiler feed water, because of its low___________________?
A. Hardness
B. Dissolved solids content
C. Suspended solids content
D. All A., B. and C. - Steam traps are provided in steam carrying pipelines to_________________?
A. Condense steam
B. Release excess steam pressure by bleeding steam
C. Remove condensate and inert gases
D. None of these - 1000 Kg of liquid at 30°C in a well stirred vessel has to be heated to 120°C, using immersed coils carrying condensing steam at 150°C. The area of the steam coils is 1.2 m2 and the overall heat transfer co-efficient to the liquid is 1500 W/m2.°C. Assuming negligible heat loss to the surrounding and specific heat capacity of the liquid to be 4 kJ/kg.°C, the time taken for the liquid to reach desired temperature will be__________________?
A. 15 min
B. 22 min
C. 44 min
D. 51 min - 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 - Loss of heat from untagged steam pipe to the ambient air is by __________________?
A. Conduction
B. Convection
C. Radiation
D. All A., B. & C. - The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re0.8, where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient varies with the pipe diameter D. as _________________?
A. D-1.8
B. D-0.2
C. D0.2
D. D1.8 - The equivalent diameter for the annulus of a double pipe heat exchanger, whose inner pipe has fins on the outside is ______________ compared to the same size pipes without fins?
A. More
B. Less
C. Same
D. Unpredictable
