190. The size of a boiler drum in pulverised fuel fired boiler,as its size and capacity, (steam pressure and flow ratings) increase
A.Increases
B.Decreases
C.Remains unchanged
D.Increases/decreases depending on steam temperature requirements
191. Feed water conditioning in thermal power plants in. done to
A.Reduce hardness and for removal of solids
B.Increase efficiency of thermal power plant
C.Increase theat tmasfer rate
D.Increase steam parameters
192. The basic job of feed water treatment in boilers is to overcome the problem of
A.Con'Ogion
B.All of the above.
C.Carryover
D.Embrittlement
193. Scale is formed on heat transfer surfaces when
A.Water is acidic
B.Water is alkaline
C.Water contains dissolved gases 77
D.Water contains dissolvt. odcium and magnesium salts
194. Hardness of water refers to
A.The presence of scale-forming calcium or magnesium salts in water -
B.Its shear strength
C.Its pH value
D.Presence of ions in water
195. Blow down from boiler drum is carried with a view to
A.Control the solids concentration in boiler water
B.To control drum level
C.Lower steam pressure
D.Increase steam temperature
196. Internal freatment of boiler _water is the feeding of chemicals directly to the boiler. It is done in order to
A.Precipitate impurities as a sludge in the water rather than as scale on the boiler metal
B.Condition the sludge to keep it from sticking to the metal so that it can be removed by blowdown
C.Adjust the water compaition to make it non-corrosive
D.All of the above
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