单选题Excessive alkalinity of the water in an auxiliary boiler can cause （）.Acaustic embrittlement of the boiler metalBacidic corrosion of the boiler metalChard scale deposits on the boiler tubesDetching of the heat exchange surfaces
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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相关考题：
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
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
The water in an auxiliary boiler should be tested for chloride content to determine ( ).A.total dissolved solidsB.salt contaminationC.water harcnessD.chlorine contamination
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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 boilerB.abnormally high feed-water temperatureC.abnormally high boiler water temperatureD.steam demand exceeding feed pump capacity
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
单选题The concentration of total dissolved solids in the water of an auxiliary boiler can increase as a result of （）.Aseawater contaminationBfrequent surface blowsCdissolved oxygen deaerationDfrequent bottom blows
单选题The most common cause of scale formation in an auxiliary boiler is （）Aconcentrations of calcium sulfate in the boiler waterBfuel oil in the feed waterCimproper treatment of the feed water with calcium sulfateDexcessive feed water alkalinity
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 （）Awill be modulated in proportionBwill be modulated in proportion and integralCwill be modulated in proportion and differentialDwill not be modulated at all
单选题The rate of heat transfer in a water-tube auxiliary boiler can be increased by （）.Aoperating the boiler at less than normal water levelBinstalling fins on the firesides of water-tubesCincreasing the amount of excess air to the burnersDtreating the boiler water with chemical oxygen scavengers
单选题In an auxiliary boiler steam and water system, the highest pressure will be in the （）.Asteam stop valveBdry pipeCfeedwater systemDgenerating tubes
单选题The correct procedure for giving an auxiliary boiler a bottom blow, is to begin（）Awhen the boiler has been secured long enough for most solids to settleBwhen the boiler has been cooled to ambient temperatureConly after raising the water level to within 0~5 inch of the high water cutout onlyDafter bypassing the low pressure
单选题Bottom blow valves are installed on auxiliary water-tube boilers to （）Aremove suspended and precipitated solids from the boiler waterBcompletely drain the boiler in an emergency situationCprevent hardened scale deposits in the water drumDremove floating impurities from the oily water surface
单选题A distorted furnace in a fire-tube auxiliary boiler may be the result of （）Afiring for extended periods in the low fire modeBoverheating, due to waterside depositsCvarying the water level above the crown sheetDcarrying excessive alkalinity in the boiler water
单选题The water in an auxiliary boiler should be tested daily for （）.Adissolved oxygenBchloridesCsludgeDdissolved nitrogen
单选题The water in an auxiliary boiler should be chemically tested daily for alkalinity and（）Asoap hardnessBnitrog encontentCchloride contentDdissolved CO2
单选题Excessive vibration of an automatically fired auxiliary boiler can be caused by （）Aair or water in the furnaceBcombustion pulsesCfuel oil pump failureDflame failure
单选题A feed pump for an auxiliary boiler might lose suction if the （）.Aboiler water level is lowBfeedwater is too hotCboiler steam demand is lowDfeedwater is too cold
单选题For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）AHigh oxygen concentrationBLow pHCProper alkalinityDAll of the above
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（）Aprecipitate silica from solutionBreduce corrosion in the heating coilCprevent clogging and erosion in the coilDmaintain zero water hardness
单选题The water in an auxiliary boiler should be tested for chloride content to determine （）.Atotal dissolved solidsBsalt contaminationCwater hardnessDchlorine contamination
单选题The amount of chloride content in the water of an auxiliary boiler can be reduced by（）Aadding hydrazineBblowing down the boilerCadding phenolphthaleinDadding a sulfite chloride scavenger
单选题Bottom blow valves are installed on auxiliary water-tube boilers to （）Acompletely drain the boiler in an emergencyBprevent sludge from forming in the drumCremove floating impurities from the boiler water surfaceDremove settled solids from the water drum
单选题If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.Ahigh steam pressure in the boilerBabnormally high feed water temperatureCabnormally high boiler water temperatureDsteam demand exceeding feed pump capacity
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 （）.A10B7C4D1
单选题The water in an operating auxiliary boiler should be tested for alkalinity and chloride content each（）.AhourBdayCweekDmonth
单选题If an operating auxiliary boiler has a water pH reading of 7, you should （）.Abottom blow the boilerBtreat the water with caustic sodaCtreat the water with chemical scavengersDreduce the water alkalinity to recommended readings