单项选择题
The vacuum maintained in the salt water feed heater shell of a flash-type evaporator is generally accomplished by （）.
A.a separate air ejector unit
B.a direct unimpeded connection between second stage and salt water feed heater
C.either by vacuum drag or an external line from the first stage via a fixed orifice
D.the fixed orifice provided in the steam supply line
点击查看答案
相关考题
-
单项选择题
In which of the listed refrigeration system components does superheating of the refrigerant take place?（）
A.Expansion valve
B.Evaporator
C.Drier
D.Receiver -
单项选择题
Excessive lube oil consumption by a reciprocating air compressor can be caused by （）.
A.using a slightly dirty air filter
B.using oil having an excessive viscosity
C.intercooler or after-cooler leaks
D.carrying the oil level higher than normal -
单项选择题
The effect of high vapor superheat in a refrigeration system, is a/an （）.
A.increased capacity of the compressor
B.more efficient operation of the thermal expansion valve
C.decreased capacity of the compressor
D.loss of receiver capacity
