In forced circulation type boiler__________________?

In forced circulation type boiler__________________?

A. heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
B. water is supplied in drum and through down-comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
C. feed pump is employed to supplement natural circulation in water wall type furnace
D. water is converted into steam in one pass without any recirculation
E. water is heated in a large number of tubes

In a recuperative air preheater, the heat is transferred____________________?

In a recuperative air preheater, the heat is transferred____________________?

A. from a metal wall from one medium to another
B. from heating an itermediate material and then heating the air from this material
C. by direct mixing ,
D. heat is transferred by bleeding some gases from furnace
E. none of the above

In designing air preheater, the important design consideration is that_________________?

In designing air preheater, the important design consideration is that_________________?

A. approach temperature should be as low as possible
B. handling and maintenance should be easier
C. heat transfer area should be optimum
D. stack gases should not be cooled to the dew point
E. none of the above