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If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.
A.high steam pressure in the boiler
B.abnormally high feed-water temperature
C.abnormally high boiler water temperature
D.steam demand exceeding feed pump capacity
参考答案
更多 “ If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.A.high steam pressure in the boilerB.abnormally high feed-water temperatureC.abnormally high boiler water temperatureD.steam demand exceeding feed pump capacity ” 相关考题
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The fuel supply system to an automatic auxiliary boiler, will be automatically shutdown if the boiler()
A.salinity is abnormallyB.high steam demand is tooC.feed-water flow is lowD.water level is abnormally low
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The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to______.A.precipitate(使沉淀) silica （硅石）from solutionB.reduce corrosion in the heating coilC.prevent clogging and erosion in the coilD.maintain zero water hardness
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单选题Which of the following items is necessary for all waste heat boiler installations, regardless of design or manufacturer? （）A
Control of evaporationB
A separate means to prevent feed-water contaminationC
Power circulating pumpD
Super-heater
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单选题The most common cause of scale formation in an auxiliary boiler is （）A
concentrations of calcium sulfate in the boiler waterB
fuel oil in the feed waterC
improper treatment of the feed water with calcium sulfateD
excessive feed water alkalinity
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单选题The purpose of a temperature sensing device installed in the stack of a small automatically fired auxiliary steam boiler is to secure the oil burner（）A
in the event of a flame failureB
in the event of a stack fireC
when the water level reach the crown sheetD
when the feed pump discharge pressure drops to a preset minimum
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单选题What is NOT a function of the steam drum of a marine water-tube boiler（）.A
Receives saturated steam from the generating tubesB
Serves as a reservoir of boiler feed waterC
Holds internal fittings for separation of moisture from steamD
Collects steam exhausted from the turbines
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单选题In the event of a flame failure in an auxiliary water-tube boiler, you must（）A
relight the boiler immediately to prevent loss of steam pressureB
relight the fire off the brickwork as the bricks are cherry redC
purge the furnace of any combustible gases before attempting to relight the fireD
speed up the feed pump to prevent dry firing when the burner flame is reestablished
考题
单选题The rate of heat transfer in a water-tube auxiliary boiler can be increased by （）.A
operating the boiler at less than normal water levelB
installing fins on the firesides of water-tubesC
increasing the amount of excess air to the burnersD
treating the boiler water with chemical oxygen scavengers
考题
单选题Improper maintenance of an automatic auxiliary boiler oil burner could result in （）.A
fuel pump failureB
fan motor failureC
increased feedwater consumptionD
decreased boiler efficiency
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单选题The boiler feed water check valves are located on the （）A
feed pump suction lineB
hot wellC
shell of the feed heaterD
feed lines to the boiler
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单选题Oxygen corrosion in auxiliary boilers is prevented by treating the boiler feed tank with either sodium （）A
sulfite or hydrazineB
sulfite or hygroscopic sulfiteC
bromide or hydrazineD
bromide or hygroscopic sulfite
考题
单选题The water in an auxiliary boiler should be tested daily for （）.A
dissolved oxygenB
chloridesC
sludgeD
dissolved nitrogen
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单选题The valve that prevents water from backing out of the boiler into the feed line is the（）.A
bottom-blow valveB
skin valveC
feed-check valveD
feed-stop valve
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单选题Excessive vibration of an automatically fired auxiliary boiler can be caused by （）A
air or water in the furnaceB
combustion pulsesC
fuel oil pump failureD
flame failure
考题
单选题A feed pump for an auxiliary boiler might lose suction if the （）.A
boiler water level is lowB
feedwater is too hotC
boiler steam demand is lowD
feedwater is too cold
考题
单选题For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）A
High oxygen concentrationB
Low pHC
Proper alkalinityD
All of the above
考题
单选题The boiler feed pump discharge pressure is higher than the steam drum pressure to （）.A
ensure feed water flow into the boilerB
keep the steam drum pressure highC
prevent water hammer in the feed lineD
help the feed water flash to steam
考题
单选题The water level in a steaming auxiliary boiler will always （）A
rise when the steam pressure is increasedB
remain constant as long as the feed pump operatesC
fall when the steam pressure is decreasedD
vary as the steam demand changes
考题
单选题The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to（）A
precipitate silica from solutionB
reduce corrosion in the heating coilC
prevent clogging and erosion in the coilD
maintain zero water hardness
考题
单选题Improper maintenance of the fuel oil burners in an automatically fired auxiliary boiler, could result in （）A
increased fuel consumptionB
increased feed water consumptionC
fuel pump failureD
combustion control system failure
考题
单选题Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?（）A
Increased suction head pressureB
Decreased feedwater temperatureC
Pump recirculating line being open too muchD
Excessive feedwater temperature
考题
单选题Excessive alkalinity of the water in an auxiliary boiler can cause （）.A
caustic embrittlement of the boiler metalB
acidic corrosion of the boiler metalC
hard scale deposits on the boiler tubesD
etching of the heat exchange surfaces
考题
单选题Bottom blow valves are installed on auxiliary water-tube boilers to （）A
completely drain the boiler in an emergencyB
prevent sludge from forming in the drumC
remove floating impurities from the boiler water surfaceD
remove settled solids from the water drum
考题
单选题The feed water to the boiler will comprise （）.A
condensateB
a small amount of make-up feedC
A and BD
None of the above
考题
单选题As for an oil-fired boiler if at a normal steaming condition and water goes out of sight in gauge glasses the action you should take is: （） (1) secure oil to fires (2) increase feed pump pressureA
（1）B
（1）and（2）C
（2）D
neither（1）nor（2）
考题
单选题If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.A
high steam pressure in the boilerB
abnormally high feed water temperatureC
abnormally high boiler water temperatureD
steam demand exceeding feed pump capacity
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