A. to reduce the boiler pressure
B. to increase the steam temperature
C. to control the solid concentration in the boiler water by removing some of the concentrated saline water
D. none of the above
Related Mcqs:
- In a boiler installation the natural draught is produced_____________?
A. due to the fact that furnace gases being light go through the chimney giving place to cold air from outside to rush in
B. due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column
C. due to the fact that at the chimney top the pressure is more than its environmental pressure
D. all of the above - For the safety of a steam boiler the number of safety valves fitted are____________?
A. four
B. three
C. two
D. one - The efficiency of a modern boiler using coal and heat recovery equipment is about_____________?
A. 25 to 30%
B. 40 to 50%
C. 65 to 70%
D. 85 to 90% - Economisers improve boiler efficiency by__________?
A. 1 to 5%
B. 4 to 10%
C. 10 to 12% - Where unpulverised coal has to be used and boiler capacity is large, the stoker which is used is______________?
A. underfeed stoker
B. overfeed stoker
C. any - In regenerative cycle feed water is heated by_____________?
A. exhaust gases
B. heaters
C. draining steam from the turbine
D. all above - Economiser is used to heat_____________?
A. air
B. feed water
C. flue gases
D. all above - The value of reheat factor normally varies from___________?
A. 0.5 to 0.6
B. 0.9 to 0.95
C. 1.02 to 1.06
D. 1.2 to 1.6 - Example of overfeed type stoker is___________?
A. chain grate
B. spreader
C. travelling grate
D. all of the above - Which of the following power plant usually offer highest maintenance cost___________?
A. Nuclear power plants
B. Hydro-electric power plants
C. Thermal power plants
D. Diesel engine power plant
