单项选择题
A distorted furnace in a fire-tube auxiliary boiler may be the result of （）
A.firing for extended periods in the low fire mode
B.overheating, due to waterside deposits
C.varying the water level above the crown sheet
D.carrying excessive alkalinity in the boiler water
相关考题
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单项选择题
Fins are installed on the fireside of water-tubes used in waste boiler to（）
A.decrease the velocity of gases flowing past the tubes
B.increase the rate of heat transfer
C.reduce accumulations carbon deposits
D.direct the flow of gases -
单项选择题
A smoking burner with a pulsating flame in auxiliary boiler, is an indication that the（）
A.fuel oil supply temperature is normal
B.burner electrode is incorrectly positioned
C.fuel／air ratio is incorrect
D.ignition current is too low -
单项选择题
The correct procedure for giving an auxiliary boiler a bottom blow, is to begin（）
A.when the boiler has been secured long enough for most solids to settle
B.when the boiler has been cooled to ambient temperature
C.only after raising the water level to within 0~5 inch of the high water cutout only
D.after bypassing the low pressure
