A. CO2
B. Dissolved O2
C. Both A. & B.
D. Neither A. nor B.
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 process stream of dilute aqueous solution flowing at the rate of10 Kg.s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s-1. A 1 – 1 shell and tube heat exchanger is available. The best arrangement is_______________?
A. Counter flow with process stream on shell side
B. Counter flow with process stream on tube side
C. Parallel flow with process stream on shell side
D. Parallel flow with process stream on tube side - 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 - The thickness of condensate layer in filmwise condensation depends on the__________________?
A. Condensation rate
B. Surface configuration
C. Liquid flow rate from the surface
D. All A., B. and C. - 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 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 - 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 - It is not preferable to use superheated steam in evaporators, because of its very_________________?
A. High temperature
B. High pressure
C. Low film co-efficient
D. None of these - Loss of heat from untagged steam pipe to the ambient air is by __________________?
A. Conduction
B. Convection
C. Radiation
D. All A., B. & C.
