單項(xiàng)選擇題

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

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單項(xiàng)選擇題

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

單項(xiàng)選擇題

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