10
7
4
1
第1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:
A.salinity is abnormally
B.high steam demand is too
C.feed-water flow is low
D.water level is abnormally low
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:
will be modulated in proportion
will be modulated in proportion and integral
will be modulated in proportion and differential
will not be modulated at all
第6题:
Before the seas get rough, it is a good safety practice to ______.
A.secure loose gear
B.move quickly about the ship
C.increase lighting
D.shutdown auxiliary equipment
第7题:
concentrations of calcium sulfate in the boiler water
fuel oil in the feed water
improper treatment of the feed water with calcium sulfate
excessive feed water alkalinity
第8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9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10题:
steam stop valve
dry pipe
feedwater system
generating tubes