Compressed air has many uses in domestic as well as in industrial sectors. Compressed air is produced with the use of equipment called a compressor. The compressor draws the atmospheric air into the compressor cylinder and increases its pressure by reducing the air volume. Into the reciprocating compressor, the air is compressed with the moving piston of the compressor. In the rotary compressor, screw, or impeller is the rotating component. Into the compressor, the air is compressed and then sent to a storage vessel called a receiver. Compressed air is stored in the air receiver at required set pressure. The pressure switch is used on-air receiver to maintain the required set pressure into the air receiver. The pressure switch sends a signal to the compressor motor, to on and off the compressor according to required air set pressure into the air receiver.
TYPE OF AIR COMPRESSOR
Following three types of air compressors are normally in service:
- Reciprocating piston
- Rotary screw
- Centrifugal impeller
Reciprocating Piston Compressor Components:
The main components of a compressor are:
(1) Compressor cylinder
(2) Reciprocating piston.
(5) Suction and Delivery valves.
Compressor Cylinder Constructional Arrangement:
(1) Single cylinder
(3) Multiple cylinders( Inline or ‘V’ line cylinder arrangement)
Working Principle Of Compressor:
During the suction stroke of the piston atmospheric air is sucked into the compressor cylinder. During the discharge stroke of the piston air is compressed by reducing its volume. Thus high-pressure air then sent to the air receiver. Compressors keep on running till the required air pressure is reached into the air receiver.
The external view of the reciprocating air compressor is shown below in the picture.
Rotary Screw Compressor:
Rotating screw air compressor has two main components (1) screw (rotor) and (2) Housing or stat-or. An annular gap is created into the stat or by some polymer lining. The screw air compressor can be a single screw or multiple screw-in constructions. The meshing screw of the compressor compresses the atmospheric air and delivers it to the air receiver till desired air set pressure is reached into the air receiver. The external view of the screw air compressor is shown below in the picture.
Centrifugal impeller air compressor:
The centrifugal impeller air compressor has two main components (1) Impeller (2) Impeller housing. Centrifugal air compressors work on centrifugal force. In a centrifugal air compressor, the air is sucked into the eye of the impeller. Rotating impeller imparts kinetic energy to the air and thus air pressure is increased. This high-pressure air then discharged through the compressor and sent to the air receiver.
COMPRESSED AIR USES
Compressed air has many uses in domestic as well as in industrial sectors. Some of the most significant uses of compressed air are discussed herewith.
(1) Automobile Industry:
In automobile manufacturing, compressed air is used to operate power tools that are used in the assembly lines of automobiles. It is used in elevators to lift automobile components for fabrication and inspection and assembly.
(2) Aerospace Industry:
Compressed air is used to elevate aircraft components for fabrication and assembly. Also used for aircraft wheel-tire inflating.
(3) Chemical and Petrochemical Industry:
Compressed air is used in chemical and petrochemical plants for their production processes such as in the drying and flushing of systems. It is used in equipment cleaning. It is used to operate actuators of process control instruments. It is used to operate a belt conveying system for coke transport for storage. To operate the control system of coke weighing machines.
(4) Transport Industry:
A huge amount of compressed air is used in the transport sectors. It is used in vehicles for their wheel Tyre inflating. It is also used to operate braking systems of all kinds of transport vehicles to control the speed of the vehicles.
(5) General Manufacturing Plant:
In manufacturing plants compressed air is used to operate power tools to carry out various operations like drilling, stamping, hammering and bolting, and lifting, etc.
(6) PACKAGING INDUSTRY:
Compressed air is used mostly in commodity packing systems. It is used to operate weighing and packaging machines. Compressed air is used for the packaging of food products, cement, coal, chemical, fertilizer, and many other products.
(7) Compressed air used in hospitals
Pressurized oxygen in cylinders is used in the ICU of hospitals.