A.Absorb erosion of high velocity discharge stream
B.Seal pump shaft against entry of air
C.Isolate the discharge side from the suction side
D.Dampen the turbulent discharge flow
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A.cooling only
B.cooling and humidifying
C.cooling and dehumidifying
D.adiabatic cooling
A.Sea water is heated to boiling temperature while under a vacuum
B.Sea water is passed over heated plates in a thin film
C.Heated sea water is injected into a vacuum chamber
D.Sea water is forced through a heated eductor
A.Vapor pockets formed in the suction flow stream
B.Rough easing volute surfaces
C.Worn wearing rings
D.Heavy fluid in the flow stream
A.primarily to lubricate the shaft seals
B.due to the inability of this type of pump to lift water to cover the suction (eye) of the impeller
C.to initially unload the pump by having its head pressure equal to discharge pressure
D.in order to overcome the potential energy of water in the discharge line
A.humidification
B.dehumidification
C.vaporization
D.evaporation
最新試題
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）
Which of the listed pumps is NOT a positive displacement pump?（）
A salinity indicator is used to determine the （）.
A grease gun is generally used to lubricate a （）.