单项选择题
A.second stage feed heater
B.saltwater feed heater
C.distillate cooler
D.second stage vapor separator
单项选择题 Small droplets of water entrained in the flashed vapor produced in a flash-type evaporator, are removed by the （）
单项选择题 The demisters installed in a flash-type evaporator serve to （）
单项选择题 A vacuum is initially established in the first and second stages of a low pressure evaporator by the use of （）