Air Compressors & Pumps Flashcards
What are the 2 categories of an air compressor?
Positive displacement and Dynamic compressors
What is a positive displacement compressor?
It draws in a charge of free air, traps it, reduces its volume, and then discharges it. The type of compressor may be either a reciprocating or rotary type.
What is a dynamic compressor?
It accelerates the air using impellers or blades, and converts the kinetic energy of the high -velocity, low pressure air into potential energy of low velocity, high pressure air.
Ex. Centrifugal and axial flow compressors
What is a reciprocating compressor?
This is when the air is compressed by a piston moving back and forth within a cylinder
What is a sliding vane compressor?
-Classed as a rotary compressor
-Consists of a cylindrical rotor having sliding vanes fitted into radial slots
What is a Rotary lobe compressor?
-classes as a rotary compressor
-has 2 figure 8 shaped impellers revolving in opposite direction
What type of pump is used for large volume, low pressure applications?
Centrifugal compressors
What are air compressor receivers used for?
It allows moisture and oil to be removed from the air
What are 2 different classes of sorbents?
Adsorbents and absorbents
What is the function of lubricants in air compressors?
-Reduce friction and resulting power loss providing a film between the surface
-Remove heat produced by friction
-Reduce corrosion by providing a coating for metal surfaces
What are the pump performance terms?
-Total static head
-Static discharge head
-Static suction lift
What are reciprocating pumps mainly used for?
(Low volume, High pressure applications)
-Chemical feeding
-Small, high pressure boiler feeder pumps
-Fuel oil pumps
(Pulse instead of smooth flow of liquid)
What are the subdivision of centrifugal pumps?
-Volute
-Diffuser
-axial flow
-mixed flow
-regenerative
What is the prime purpose of having a pump?
To transfer a fluid from one place to another
What are 2 classifications of pumps?
Dynamic and positive displacement
What is a device in a centrifugal pump that makes the conversion rom kinetic energy (Velocity) to potential energy (pressure) more effective?
Diffuser
Wear rings for a centrifugal pump can be installed on to where?
Impeller or casing or both
What are wear rings constructed of?
Bronze or cast-iron
What will flexible couplings compensate for?
Axial shaft realignment
Most pump failure and damage occur when?
During initial start up
Pertaining to oils, explain what are the flash and fire points
The flashpoint of a oil is the temperature at which the oil will give off sufficient vapor to ignite momentarily when mixed with air, and exposed to a source of ignition
The fire point of an oil is the temperature at which enough vapor is given off to burn continuously
Bearings can withstand operating temperatures up to?
120 C (185F)
