A. Condense steam
B. Release excess steam pressure by bleeding steam
C. Remove condensate and inert gases
D. None of these
Related Mcqs:
- 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. - 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 - Which of the following is the most widely used heat insulating material for pipelines carrying steam ?
A. Tar dolomite bricks followed by asbestos
B. Fireclay refractory followed by aluminium sheet
C. Cotton followed by aluminium foil
D. 85% magnesia cement and glass wool - 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 - 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 - A BTU/hr.ft.2 °F is equal to_________________?
A. 1 kcal/hr. m2°C
B. 4.88 kcal/hr. m.2°C
C. 1 kcal/hr. m2.°K
D. None of these - Nusselt number is the ratio of the temperature gradient at the wall to_________________?
A. Temperature difference
B. Heat flux
C. That across the entire pipe
D. None of these - In case of evaporators, liquid entrainment results primarily due to_________________?
A. High vacuum in the evaporator
B. High evaporation rate
C. Foaming of the solution
D. High heat transfer rate - The purpose of floating head in a heat exchanger is to_________________?
A. Avoid buckling of tubes
B. Provide support for tubes
C. Decrease the pressure drop
D. Facilitate its lengthening, if needed
