单项选择题
A.combined as part of the salt water feed heater
B.the open area above the brine levels in the first and second stages
C.combined as part of the distillate cooler
D.another term used to describe the vapor feed heater
单项选择题 Early models of the flash-type evaporators used a separate shell-and-tube heat exchanger as the air ejector condenser.More recent models use a combined air ejector condenser with the（）
单项选择题 The second stage feed-water temperature and shell absolute pressure in a multistage, flash type, distilling plant is （）
单项选择题 The efficiency of a flash type evaporator can be increased by（）