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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
参考答案
更多 “ 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 ” 相关考题
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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
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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
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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（）.A
increase the flow of the cooling water through the condenserB
adjust the high pressure cutout to maintain the desired pressureC
open the hot gas bypass temporarily to reduce capacityD
purge non-condensable gases to reduce the excess pressure
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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.A
pressureB
temperatureC
densityD
volume
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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
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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
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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
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单选题The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.A
remain constant along the tubes lengthB
be greatest in a single pass counter flow heat exchangerC
remain constant throughout the heat exchangerD
vary from section to section through out the heat exchanger
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
None of the above is true
考题
单选题The purpose of the programmed purge cycle on an automatically fired auxiliary boiler is to（）A
cool the furnace to prevent pre-ignitionB
remove explosive vapors from the furnaceC
evaporate accumulated unburned fuel oilD
provide sufficient air in the furnace to allow ignition of the fuel
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单选题Which of the following statements concerning fire-tube boilers is correct?（）A
Combustion gases flow through the tubesB
Flames impinge on the tubesC
Combustion occurs in the tubesD
Water flows through the tubes
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单选题Why will a two stage flash type distilling plant tend to operate more efficiently when operating in cold seawater?（）A
The colder seawater passing through the condenser tube bundles of the various stages increases evaporator vacuumB
The amount of heated feed water discharged from the feed water heater after cndenser is increasedC
Fewer non-condensable gases are created by the flow of colder seawaterD
More seawater is allowed to pass through the flint stage overflow weir
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单选题In （）, hot diesel engine jacket water passes over the stack and heats the sea water passing through the tubes.A
a flash generatorB
a flash evaporatorC
a vacuum boiling evaporatorD
a boiler
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单选题Fins are installed on the fireside of water-tubes used in waste boiler to（）A
decrease the velocity of gases flowing past the tubesB
increase the rate of heat transferC
reduce accumulations carbon depositsD
direct the flow of gases
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单选题What does blowing tubes accomplish?（）A
Eliminates unburned fuel oil residues from the fireboxB
Increases boiler efficiencyC
Flushes away mineral deposits inside the water tubesD
Cleans soot deposits from the inside of the stack
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单选题Because of the reduced （） in the vacuum boiling evaporator, some of the sea water boils as it flows through the tubes.A
temperatureB
water levelC
pressureD
rate of flow
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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
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单选题A new water boiler was installed in our building last week, which could provide hot water to the students.A
inspected carefullyB
placed in serviceC
undertaken with careD
undone casual
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单选题Impurities from the boiler water surface can be removed through the （）.A
safety valveB
blow down valveC
scum valveD
feed check valve
考题
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.A
disposeB
dissolveC
heatD
dissipates
考题
单选题When steam is being raised on a boiler, the water level will normally （）.A
drop as the boiler warms upB
rise as the boiler warms upC
remain unchanged until the boiler is hot enoughD
rise and fall with the steam demand
考题
单选题To avoid impingement attack, care must be taken with the water （） through the tubes of the heat exchangers.A
temperatureB
velocityC
densityD
viscosity
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One of the main purposes of refractories in a boiler furnace is to（）A
help preheat the air for the furnacesB
help preheat the feedwaterC
protect economizer from excessive heatD
prevent excessive furnace heat losses
考题
单选题In a （） boiler the water flows through the inside of the tubes while the hot gases pass around the outside.A
water-tubeB
fire-tubeC
exhaust gasD
none of the above
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