In a ______boiler the hot gases from the furnace pass through the tubes while the water is on the outside.A.water-tubeB.fire-tubeC.exhaust gasD.Composite
In a ______boiler the hot gases from the furnace pass through the tubes while the water is on the outside.
A.water-tube
B.fire-tube
C.exhaust gas
D.Composite
相关考题：
In a()boiler the hot gases from the furnace pass gases from the furnace pass water is on the outside. A.water-tubeB.fire-tubeC.exhaust gasD.composite
In the event of the cylinder starting valve leakage ______would pass into the air pipes and ignite the oil deposited.A.cooling waterB.vapor from the boilerC.starting airD.hot gases
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If a large difference exists between the compressor discharge pressure and the pressure corresponding to the existing condensing temperature in a refrigeration system, you should（）.Aincrease the flow of the cooling water through the condenserBadjust the high pressure cutout to maintain the desired pressureCopen the hot gas bypass temporarily to reduce capacityDpurge non-condensable gases to reduce the excess pressure
单选题Because of the reduced （） in the distillation system, some of the sea water boils as it flows through the tubes of the evaporator.ApressureBtemperatureCdensityDvolume
单选题In the event of a flame failure in an auxiliary water-tube boiler, you must（）Arelight the boiler immediately to prevent loss of steam pressureBrelight the fire off the brickwork as the bricks are cherry redCpurge the furnace of any combustible gases before attempting to relight the fireDspeed up the feed pump to prevent dry firing when the burner flame is reestablished
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The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.Aremain constant along the tubes lengthBbe greatest in a single pass counter flow heat exchangerCremain constant throughout the heat exchangerDvary from section to section through out the heat exchanger
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In a （） boiler the hot gases from the furnace pass through the tubes while the water is on the outside.Awater-tubeBfire-tubeCexhaust gasDNone of the above is true
单选题The purpose of the programmed purge cycle on an automatically fired auxiliary boiler is to（）Acool the furnace to prevent pre-ignitionBremove explosive vapors from the furnaceCevaporate accumulated unburned fuel oilDprovide sufficient air in the furnace to allow ignition of the fuel
单选题Which of the following statements concerning fire-tube boilers is correct?（）ACombustion gases flow through the tubesBFlames impinge on the tubesCCombustion occurs in the tubesDWater flows through the tubes
单选题Why will a two stage flash type distilling plant tend to operate more efficiently when operating in cold seawater?（）AThe colder seawater passing through the condenser tube bundles of the various stages increases evaporator vacuumBThe amount of heated feed water discharged from the feed water heater after cndenser is increasedCFewer non-condensable gases are created by the flow of colder seawaterDMore seawater is allowed to pass through the flint stage overflow weir
单选题In （）, hot diesel engine jacket water passes over the stack and heats the sea water passing through the tubes.Aa flash generatorBa flash evaporatorCa vacuum boiling evaporatorDa boiler
单选题Fins are installed on the fireside of water-tubes used in waste boiler to（）Adecrease the velocity of gases flowing past the tubesBincrease the rate of heat transferCreduce accumulations carbon depositsDdirect the flow of gases
单选题What does blowing tubes accomplish?（）AEliminates unburned fuel oil residues from the fireboxBIncreases boiler efficiencyCFlushes away mineral deposits inside the water tubesDCleans soot deposits from the inside of the stack
单选题Because of the reduced （） in the vacuum boiling evaporator, some of the sea water boils as it flows through the tubes.AtemperatureBwater levelCpressureDrate of flow
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A new water boiler was installed in our building last week, which could provide hot water to the students.Ainspected carefullyBplaced in serviceCundertaken with careDundone casual
单选题Impurities from the boiler water surface can be removed through the （）.Asafety valveBblow down valveCscum valveDfeed check valve
单选题When a vacuum boiling evaporator works, the hot jacket water will pass over the tube stack and （） the sea water passing through the tubes.AdisposeBdissolveCheatDdissipates
单选题When steam is being raised on a boiler, the water level will normally （）.Adrop as the boiler warms upBrise as the boiler warms upCremain unchanged until the boiler is hot enoughDrise and fall with the steam demand
单选题To avoid impingement attack, care must be taken with the water （） through the tubes of the heat exchangers.AtemperatureBvelocityCdensityDviscosity
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One of the main purposes of refractories in a boiler furnace is to（）Ahelp preheat the air for the furnacesBhelp preheat the feedwaterCprotect economizer from excessive heatDprevent excessive furnace heat losses
单选题In a （） boiler the water flows through the inside of the tubes while the hot gases pass around the outside.Awater-tubeBfire-tubeCexhaust gasDnone of the above