單項(xiàng)選擇題
A.carbon deposits on the flame scanner B.high fuel oil temperature C.low fuel oil viscosity D.high steam pressure
A.water in the fuel oil B.excessive cycling C.high fuel oil pressure D.improper burner maintenance
A.cool the furnace to prevent pre-ignition B.remove explosive vapors from the furnace C.evaporate accumulated unburned fuel oil D.provide sufficient air in the furnace to allow ignition of the fuel
A.precipitate silica from solution B.reduce corrosion in the heating coil C.prevent clogging and erosion in the coil D.maintain zero water hardness
A.cyclone furnace boiler type B.dry back boiler type C.water-tube type D.critical circulation boiler type
A.fire-tube controlled circulation B.fire-tube supercritical circulation C.water-tube natural circulation D.water-tube express circulation
A.Natural convection only B.Forced convection only C.Both natural convection and forced convection D.None
A.water-tube natural circulation boilers B.fire-tube boilers C.water-tube forced circulation boilers D.all of the above
A.The pistons reciprocate B.The ‘B’ end cylinder barrel rotates C.There is no fluid flow D.Power is transmitted hydraulically
A.20 B.40 C.60 D.80
A.modulating the oil flow with the six-way valve B.moving the automatic pressure differential valve C.moving the receiving telemotor which regulates the tow-way valve D.varying the eccentricity of a floating ting or angle of a tilting box
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