单项选择题
A.clearance B.crush C.pitch D.thrust
If an operating auxiliary boiler has a water pH reading...
单项选择题If an operating auxiliary boiler has a water pH reading of 7, you should （）.
A.bottom blow the boiler B.treat the water with caustic soda C.treat the water with chemical scavengers D.reduce the water alkalinity to recommended readings
Generating tubes in waste heat boilers are finned to （）...
单项选择题Generating tubes in waste heat boilers are finned to （）.
A.reduce gas flow turbulence B.prevent exhaust gas corrosion C.increase the rate of combustion D.increase the rate of heat transfer
Directional intake ports in diesel engines are used to ...
单项选择题Directional intake ports in diesel engines are used to （）.
A.reduce air charge turbulence B.induce air swirl C.deflect hot combustion gas away from the valves D.oppose the effects of piston induced squish
