单项选择题Too much air in the furnace of an oil-fired boiler would be indicated by ().

A.yellowish flame
B.golden yellow flame
C.white flame
D.brilliant white flame


您可能感兴趣的试卷

你可能感兴趣的试题

1.单项选择题The feed water to the boiler will comprise ().

A.condensate
B.a small amount of make-up feed
C.A and B
D.None of the above

2.单项选择题Proper combustion in a boiler would be indicated by ().

A.yellowish flame
B.golden yellow flame
C.white flame
D.brilliant white flame

3.单项选择题Black smoke coming from a boiler can be caused by ().

A.low water level
B.low oil pressure
C.excessively high fuel pressure
D.an improper air/fuel ratio

4.单项选择题Which of the following pumps belongs to centrifugal pump?()

A.Reciprocating pump
B.Screw pump
C.Diffuser pump
D.Water-ring pump

5.单项选择题The advantage of a centrifugal pump as compared with a reciprocating pump is that ().

A.discharge is continuous
B.it has no internal valves
C.upon accidental closing of discharge valve, excessive pressure will not build up
D.all of the above are true

6.单项选择题A pump is said to have "negative suction head" when the pump is located ().

A.between the suction and discharge
B.below the liquid supply
C.above the liquid supply
D.any of the above

7.单项选择题

Which of the following pumps are self-priming, and can deal with liquid from a level below the pump? ()
(1) reciprocating
(2) vane
(3) gear

A.(1)only
B.(1)and(2)
C.(1),(2)and(3)
D.(2)and(3)

8.单项选择题

Which of the following pumps are self-priming, and can deal with liquid from a level below the pump? ()
(1) reciprocating
(2) rotary
(3) centrifugal

A.(1)only
B.(1)and(2)
C.(1),(2)and(3)
D.(2)and(3)

9.单项选择题A positive displacement pump is that where the volume of the pump chamber is alternately () to draw the liquid in and then () to force the liquid out.

A.increased;decreased
B.decreased;increased
C.decreased;decreased
D.increased;increased

10.单项选择题The pressure head of a water pump is given in the unit of ().

A.kg
B.MPa
C.mH20
D.None of the above