单项选择题
A.After B.before C.inside D.outside
For a flash type evaporator, the seawater heater will h...
单项选择题For a flash type evaporator, the seawater heater will have to maintain a enough temperature to minimize scale formation（）
A.lower B.higher C.low D.high
The flash-evaporator is different with the submerged-tu...
单项选择题The flash-evaporator is different with the submerged-tube evaporator in that for the former（）
A.Water is heated into vapor on heating surfaces B.Water is vaporized by pressure difference C.There are no heating-transfer surfaces D.There are more heating-transfer surfaces
Which one of the followings might not be employed to cr...
单项选择题Which one of the followings might not be employed to create vacuum for flash type evaporator? （）
A.high-pressure steam-driven air-ejector B.motor-driven vacuum pump C.water-motivated air eductor D.centrifuge pump
