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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 pressure

B.relight the fire off the brickwork as the bricks are cherry red

C.purge the furnace of any combustible gases before attempting to relight the fire

D.speed up the feed pump to prevent dry firing when the burner flame is reestablished

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

A donkey boiler is also called ()

A.a main boiler

B.an auxiliary boiler

C.an exhaust gas boiler

What is it claimed may be observed when looking at the brickwork of a house？

A．Sunshine causes its color to seem soothing.

B．The natural color is emphasized when the sun goes in.

C．The bricks appear to be brighter in color in sunlight.

D．Painted bricks are very intense in coloring.

A.natural circulation of the water in the water tube boiler is better than that in the fire tube boiler

B.for the same output the water tube boiler will carry less mass of water compared with the fire tube boiler

C.the water tube boiler will cost shorter time for steam raising

D.the water tube boiler require lower skill in operating and maintaining

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

Diesel engine waste heat boiler construction is usually of the fire-tube or .

A.cyclone furnace boiler type

B.dry back boiler type

C.water-tube type

D.critical circulation boiler type

When steam is being raised on a boiler, the water level will normally _____.

A.drop as the boiler warms up

B.rise as the boiler warms up

C.remain unchanged until the boiler is hot enough

D.rise and fall with the steam demand

The rate of heat transfer in a water-tube auxiliary boiler can be increased by .

A.operating the boiler at less than normal water level

B.installing fins on the firesides of water-tubes

C.increasing the amount of excess air to the burners

D.treating the boiler water with chemical oxygen scavengers

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