单项选择题
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
A smoking burner with a pulsating flame in auxiliary bo...
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
The correct procedure for giving an auxiliary boiler a ...
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
Bottom blow valves are installed on auxiliary water-tub...
单项选择题Bottom blow valves are installed on auxiliary water-tube boilers to （）
A.completely drain the boiler in an emergency B.prevent sludge from forming in the drum C.remove floating impurities from the boiler water surface D.remove settled solids from the water drum
