Module 1 Flashcards
A compressor that compresses air to only one end of a cylinder
Single-acting compressor
Cooling air between compressor stages
Intercooling
Cooling air after it leaves the compressor
Aftercooling
Heat exchanger design where cooling water and air flow in opposite directions
Counterflow
Heat exchanger design where cooling water and air flow in the same direction
Parallel flow
relieving all internal pressure from the compressor
Unloading
As a compressor increases the air pressure, it also reduces the air _____.
Volume
What are the two classifications of air compressors when distinguished by their operating principles?
Positive displacement, Dynamic
Name the two methods used to connect the compressor drive to the compressor.
Direct Driven, V-Belt Driven
The movable part of a discharge valve is held in place by a(n) _____.
Spring
A compressor that compresses air in more than one step is called a(n) _____ compressor.
Multistage
Cooling the air between stages in a multistage compressor reduces the _____ requirements.
Horsepower
Water-cooled intercoolers are usually _____ heat exchangers.
Shell-and-Tube
The most efficient and commonly found flow arrangement in a water-cooled intercooler is _____.
Counterflow
Cylinder-wall lubrication prevents piston rings from wearing, and _____.
Removes Heat
The two basic methods used to lubricate a compressor are _____ lubrication and _____ lubrication.
Splash, Pressurized
The lubrication method that is used for heavy-duty compressors is _____ lubrication.
Pressurized
If oil-free air is required, compressors are used that require _____ lubrication or have only _____ lubrication.
No; Well-isolated bearing
A large compressor is started only when the compressor is _____.
Unloaded
Name at least two devices used to control pressure in a compressor.
Pressure Switch, Suction Unloader Valves, Centrifugal Pressure Release, Hydraulic unloader, Electric or Magnetic Unloader
An alternate way of causing compressor output to vary is to change the _____ of the compressor.
Speed
Name at least two advantages of reciprocating compressors.
Good Compression Ratios, Variety of Sizes, Low Operating Cost, and High Output in FT3/MIN/HP
To be efficient, a positive displacement compressor must decrease the air’s _____.
Volume
Dynamic compressors increase air pressure by _____.
Accelerating the air.
The discharge valves of a compressor are opened by _____.
Compressed air.
In which of the following ways are discharge valves closed?
a. Electrical impulse
b. Gravity
c. Piston linkage
d. Spring action
d. Spring action
In multistage compressors, the required air pressure is created by compressing the air in _____.
Two or more unequal cylinders.
Of what benefit is the use of an intercooler in a multistage compressor?
Decreases horsepower requirements.
Air-cooled compressors are usually constructed with _____.
Cooling fins.
Water or liquid intercoolers are usually patterned after which of the following?
a. Automotive radiator
b. Evaporative coolers
c. Finned radiators
d. Shell-and-tube heat exchangers
D. Shell-and tube heat exchangers.
What lubrication method is used for heavy-duty compressors?
Pressurized
When a compressor is relieved of all internal pressure, it is said to be _____.
Unloaded.
