单项选择题In a flash evaporator, scale as a result of higher than normal temperatures in most likely to occur in the ()

A.second stage feed heater
B.saltwater feed heater
C.distillate cooler
D.second stage vapor separator


您可能感兴趣的试卷

你可能感兴趣的试题

2.单项选择题The demisters installed in a flash-type evaporator serve to ()

A.deaerate the first effect distillate
B.filter the condensed flash vapors
C.deaerate the first and second effect distillate
D.remove small water droplets entrained in the flashed vapor

3.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 ()

A.vacuum drag from the auxiliary condensate system
B.individual vacuum pumps
C.a single non-condensing air ejector
D.a two stage air ejector

4.单项选择题The heated feed-water entering any flash chamber of a flash-type evaporator will()

A.vaporize, with the un-flashed water remaining at the temperature at which it entered the flash chamber
B.vaporize, with the un-flashed eater equalizing to the saturation conditions existing in the f lash chamber
C.vaporize, with the remaining water a t a temperature greater than it entered the flash chamber
D.boil, allowing steam bubbles to rise through the brine at the bottom of the flash chamber

5.单项选择题On a multistage flash-type evaporator, the flash chamber is ()

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

7.单项选择题The second stage feed-water temperature and shell absolute pressure in a multistage, flash type, distilling plant is ()

A.higher than the first stage feed-water temperature and absolute shell pressure
B.lower than the first stage feed-water temperature and absolute shell pressure
C.the same as the first stage feed-water temperature and absolute shell pressure
D.not related to the feed-water temperature and absolute shell pressure

8.单项选择题The efficiency of a flash type evaporator can be increased by()

A.lowering brine discharge density
B.decreasing the absolute pressure of each stage
C.increasing the saltwater feed heater temperature
D.increasing the pressure at the spray pipe

10.单项选择题Valve lash, or clearance refers to the ()

A.clearance between the top of the valve stem and the rocker arm
B.compression of the valve springs
C.clearance between the valve seat inserts and the head
D.out of roundness of the fuel injection cams