The brickwork surrounding the firebox of a boiler is known as ______.
A.Refractory
B.The screen wall
C.The water wall
D.Fire plate
第1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 boiler
B.abnormally high feed-water temperature
C.abnormally high boiler water temperature
D.steam demand exceeding feed pump capacity
第2题:
A firebox explosion in an automatically fired auxiliary boiler may be the result of ______.
A.excessive purging before lighting off
B.insufficient trail for ignition period
C.a faulty transformer in the ignition circuit
D.insufficient purging before lighting off
第3题:
natural circulation of the water in the water tube boiler is better than that in the fire tube boiler
for the same output the water tube boiler will carry less mass of water compared with the fire tube boiler
the water tube boiler will cost shorter time for steam raising
the water tube boiler require lower skill in operating and maintaining
第4题:
operating the boiler at less than normal water level
installing fins on the firesides of water-tubes
increasing the amount of excess air to the burners
treating the boiler water with chemical oxygen scavengers
第5题:
swell
shrinkage
flash off
lack of water
第6题:
steam demand is high
salinity is high
safety valve simmers
burner flame is extinguished
第7题:
Absolute moisture content of the air surrounding a hygroscopic cargo when moisture equilibrium exists
Dew point temperature that the air surrounding a hygroscopic commodity will have when in moisture equilibrium with that commodity
Enthalpy of the air surrounding a hydroscopic cargo which is in moisture equilibrium with the cargo
Temperature at which moisture equilibrium will occur in a cargo hold containing a hygroscopic cargo
第8题:
directional current
forward current
propeller current
wake current
第9题:
The boiler oil tank
The steam pipe
The fire side
The safety valves
第10题:
drop as the boiler warms up
rise as the boiler warms up
remain unchanged until the boiler is hot enough
rise and fall with the steam demand
第11题:
high steam pressure in the boiler
abnormally high feed water temperature
abnormally high boiler water temperature
steam demand exceeding feed pump capacity
第12题:
refractory
the screen wall
the water wall
fire plate
第13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 solution
B.reduce corrosion in the heating coil
C.prevent clogging and erosion in the coil
D.maintain zero water hardness
第14题:
Which statement about the inert gas system is TRUE ________.
A.Boiler soot blowers should never be used when the IG system is operating
B.The boiler will produce the best quality of flue gas for the IG system when the boiler load is very light
C.The boiler will produce the most quantity of flue gas for the IG system when the boiler load is very light
D.Flue gas with excessive oxygen content is de-oxygenated in the scrubber
第15题:
relight the boiler immediately to prevent loss of steam pressure
relight the fire off the brickwork as the bricks are cherry red
purge the furnace of any combustible gases before attempting to relight the fire
speed up the feed pump to prevent dry firing when the burner flame is reestablished
第16题:
when the boiler has been secured long enough for most solids to settle
when the boiler has been cooled to ambient temperature
only after raising the water level to within 0~5 inch of the high water cutout only
after bypassing the low pressure
第17题:
salinity is abnormally high
steam demand is too high
water level is abnormally low
feedwater flow is low
第18题:
excessive purging before lighting off
insufficient trail for ignition period
a faulty transformer in the ignition circuit
insufficient purging before lighting off
第19题:
monkey
donkey
waste heat
main
第20题:
precipitate silica from solution
reduce corrosion in the heating coil
prevent clogging and erosion in the coil
maintain zero water hardness
第21题:
oxygen in the water
poor boiler design
density too high
excessive steam demand
第22题:
caustic embrittlement of the boiler metal
acidic corrosion of the boiler metal
hard scale deposits on the boiler tubes
etching of the heat exchange surfaces
第23题:
10
7
4
1