更多"When a flash-type evaporator is to "的相关试题:
[单项选择]When the water produced from most evaporator is supplied for drinking purpose, it must be treated to ensure it is biologically pure and （）.
A. slightly acidic
B. slightly alkaline
C. no salty
D. slightly bitter
[单项选择]When a vacuum boiling evaporator works, the hot jacket water will pass over the tube stack and （） the sea water passing through the tubes.
A. dispose
B. dissolve
C. heat
D. dissipates
[单项选择]When securing a flash-type evaporator for an extended period of time, you should （）.
A. fill the unit with saltwater
B. fill the unit with de-scaling compound
C. completely drain the unit
D. tightly seal the unit to exclude air
[单项选择]Anchors are prevent from running out when secured by the（）.
A. brake
B. devil's claw
C. pawls
D. All of the above
[单项选择]When a deck cargo is secured with chain or wire lashings and grab (pear) links，which statement is FALSE?（）
A. The amount of take-up is limited by the length of the turnbuckle
B. At the grab (pear) link，the slack end of chain should be led back and secured to the chain above the link
C. The lashings should be inspected each day and any slack taken up
D. The turnbuckle should be secured with a stick or lock nuts
[单项选择]Scale accumulation on evaporator heat exchange surfaces （）.
A. increases brine density
B. increases distillate salinity
C. reduces metal corrosion
D. reduces heat transfer
[单项选择]Constant superheat is maintained at the evaporator outlet of a refrigeration coil by a（）
A. solenoid valve
B. low pressure cutout switch
C. king valve
D. thermal expansion valve
[单项选择]Less scale formation occurs in a flash evaporator than in a submerged tube evaporator because （）.
A. the distillate produced has greater purity
B. no boiling occurs on heat transfer surfaces
C. evaporation occurs at a higher rate
D. the incoming feed is at a higher temperature
[单项选择]The refrigerant leaves the evaporator of a refrigeration system as a low pressure （）.
A. sub-cooled liquid
B. high temperature liquid
C. oil saturated liquid
D. superheated vapor
[单项选择]Distilled water from an evaporator may be discharged into a potable water tank （）.
A. through a detachable hose connection
B. after passing through an activated charcoal filter
C. after chemical analysis shows it is fit for consumption
D. through a solenoid operated three-way valve
[单项选择]The refrigerant flows through the evaporator, where it （） heat from the refrigerated space.
A. extracts
B. releases
C. gives no
D. absorbs no
[单项选择]A flash-type evaporator discharges heated seawater into a chamber that is maintained at a pressure than the vapor pressure of the entering heated seawater, and subsequently the flashed water vapor thereby produced（）
A. lower condensing
B. higher cooling
C. lower cooling
D. higher condensing
[单项选择]The steam coils in a high pressure evaporator used for saltwater service should be de-scaled with （）.
A. a needle gun
B. soap and water
C. a wire brush
D. a chipping hammer
[单项选择]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
[单项选择]In the operation of a flash type evaporator equipped with air ejectors,the air and non- condensable gases are evacuated directly from the （）.
A. first stage flash chamber
B. second stage flash chamber
C. first stage after condenser
D. second stage distilling condenser
[单项选择]In a flash type evaporator, all saltwater headers are vented through individual vent cocks to the（）.
A. saltwater heater shell
B. second-stage condenser
C. atmosphere
D. second-stage flash chamber
[单项选择]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
[单项选择]With a vacuum boiling evaporator, the remainder of sea water fed to the evaporator is pumped out by （）.
A. a brine pump
B. an air ejector
C. a feed pump
D. distillate pump
[单项选择]In a flash distilling unit, evaporator feed (seawater) first absorbs heat in the （）.
A. vapor feed heater
B. air ejector condenser
C. saltwater heater
D. distillate cooler
