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单选题
Excessive alkalinity of the water in an auxiliary boiler can cause （）.
A
caustic embrittlement of the boiler metal
B
acidic corrosion of the boiler metal
C
hard scale deposits on the boiler tubes
D
etching of the heat exchange surfaces
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更多 “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” 相关考题
考题
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 settleB.when the boiler has been cooled to ambient temperatureC.only after raising the water level to within 0.5 inch of the high water cutout onlyD.after bypassing the low pressure
考题
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
考题
The water in an auxiliary boiler should be tested for chloride content to determine ( ).A.total dissolved solidsB.salt contaminationC.water harcnessD.chlorine contamination
考题
what chemicals did you use to treat the boiler water ?when you test alkalinity and acidity of water in boiler by pH test paper ? the result shows the boiler water is in acidiity . please describe what the possible cause is .
考题
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
考题
The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to______.A.precipitate(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
考题
单选题The concentration of total dissolved solids in the water of an auxiliary boiler can increase as a result of （）.A
seawater contaminationB
frequent surface blowsC
dissolved oxygen deaerationD
frequent bottom blows
考题
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
考题
单选题The water level of an exhaust gas boiler which is independent of the auxiliary boiler and just as the extra heating surface of it （）A
will be modulated in proportionB
will be modulated in proportion and integralC
will be modulated in proportion and differentialD
will not be modulated at all
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In an auxiliary boiler steam and water system, the highest pressure will be in the （）.A
steam stop valveB
dry pipeC
feedwater systemD
generating tubes
考题
单选题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 settleB
when the boiler has been cooled to ambient temperatureC
only after raising the water level to within 0~5 inch of the high water cutout onlyD
after bypassing the low pressure
考题
单选题Bottom blow valves are installed on auxiliary water-tube boilers to （）A
remove suspended and precipitated solids from the boiler waterB
completely drain the boiler in an emergency situationC
prevent hardened scale deposits in the water drumD
remove floating impurities from the oily water surface
考题
单选题A distorted furnace in a fire-tube auxiliary boiler may be the result of （）A
firing for extended periods in the low fire modeB
overheating, due to waterside depositsC
varying the water level above the crown sheetD
carrying excessive alkalinity in the boiler water
考题
单选题The water in an auxiliary boiler should be tested daily for （）.A
dissolved oxygenB
chloridesC
sludgeD
dissolved nitrogen
考题
单选题The water in an auxiliary boiler should be chemically tested daily for alkalinity and（）A
soap hardnessB
nitrog encontentC
chloride contentD
dissolved CO2
考题
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 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The water in an auxiliary boiler should be tested for chloride content to determine （）.A
total dissolved solidsB
salt contaminationC
water hardnessD
chlorine contamination
考题
单选题The amount of chloride content in the water of an auxiliary boiler can be reduced by（）A
adding hydrazineB
blowing down the boilerC
adding phenolphthaleinD
adding a sulfite chloride scavenger
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
考题
单选题Before an auxiliary boiler is shutdown for an extended period of time, the water in the boiler should have a pH value of （）.A
10B
7C
4D
1
考题
单选题The water in an operating auxiliary boiler should be tested for alkalinity and chloride content each（）.A
hourB
dayC
weekD
month
考题
单选题If an operating auxiliary boiler has a water pH reading of 7, you should （）.A
bottom blow the boilerB
treat the water with caustic sodaC
treat the water with chemical scavengersD
reduce the water alkalinity to recommended readings
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