Which one of the following statements is not correct?
In a fluidized-bed boiler
Option (A)
the combustion temperatures are higher than those in the conventional boilers
Option (B)
inferior grade of coal can be used without slagging problems
the formation of NOX is less than that in the conventional boilers
the volumetric heat release rates are higher than those in the conventional boilers
Correct Option:
Question Solution:
Fluidized bed boiler allow interior grades of coal to be sued without slagging problems. The carbon and ash carry over in the flue gases does not reach high temperature at which they become soft and foul heat transfer surface. The low temperature combustion results in substantial reduction in the emission of oxides of nitrogen NO2 a serious pollutant and cheaper alloy material are possible resulting in economy of combustion.