The compressor is a mechanical device that increases the pressure of a gas by reducing its volume. It is used to increase the pressure of air from low pressure to high pressure by using some external energy. Compressors are similar to pumps: which increase the pressure on a fluid and can transport the fluid through a pipe.
Types of compressors
1. Rotary screw compressor
Rotary air compressors are positive displacement compressors. The most common rotary air compressor is the single-stage helical or spiral lobe oil flooded screw air compressor. These compressors consist of two rotors within a casing where the rotors compress the air internally. There are no valves. These units are basically oil cooled (with air-cooled or water-cooled oil coolers) where the oil seals the internal clearances. Since the cooling takes place right inside the compressor, the working parts never experience extreme operating temperatures. The rotary compressor, therefore, is a continuous duty, air-cooled or water-cooled compressor package.
● They are generally used to supply compressed air for larger industrial applications.
● They are best applied in applications that have a continuous air demand such as food packaging plants and automated manufacturing systems although a large enough number of intermittent demands, along with some storage.
● They are incredibly convenient.
● They are easier to maintain.
● They are designed to run tools that generate more power than typical equipment.
● They are good energy conservers
● Special maintenance is required.
● Quite expensive
2. Centrifugal compressor
A centrifugal compressor is a type of dynamic compressor or turbocompressor, with a radial design. Unlike displacement compressors that work at a constant flow, dynamic compressors work at constant pressure and the performance is affected by external conditions such as changes in inlet temperatures.
● Food and beverage industry - the centrifugal compressor provides oil-free compressed air for some sensitive applications such as food processing.
● Centrifugal compressor meets the high demand of the compressed air.
● Gas turbines, in automobile turbochargers and superchargers.
● Oil refineries, natural-gas processing.
● Low weight, easy to design and manufacture.
● Suitable for continuous compressed air supply, such as cooling unit
● They are oil-free in nature.
● They have fewer rubbing parts.
● High-flow rate than the positive displacement compressor.
● Large frontal area for a given airflow rate compared to the axial flow compressor.
● Unsuitable for very high compression, limited pressure.
● They are sensitive to changes in gas composition.
● They work at high speed, sophisticated vibration mounting needed.
3. Reciprocating Compressor
Reciprocating air compressors work on the principle of reciprocation, which means to move something back and forth. Also known as piston compressors, these machines are positive displacement equipment, meaning that they increase pressure in air to compress it. Understanding reciprocating compressor design and the types of compressors available is essential to choosing the right model for your application, whether you’re a home artisan or run a factory floor.
● Sandblasters in machine shops or factories
● Wood or auto body sanding
● Spray painting for vehicles
● Dental and some medical tools
● Used to produce high-pressure gas.
● It can compress gases and refrigerants of a wide range of molecular density.
● High efficiency and flexibility.
● Cheap and rugged design.
● The size of the compressor is very large for a given capacity.
● Part of the work input is lost due to frictional resistance between the piston and cylinder.
● Pulsating of fluid flow. The operation can be made smooth by using a flywheel.
● High vibration and noise.
Uses of compressor
Air compressors are found in a wide range of environments for an even wider range of uses. You’ll see gas stations offering compressed air to inflate your vehicle’s tires and your tire shop using compressed air with an air tool to remove your tires. You may have seen small desktop air compressors used with an airbrush or a trailer-style gas-powered air compressor at a construction site powering jackhammers and concrete compactors. Air compressors have a multitude of uses for leisure and maintenance at home or in businesses to get work done efficiently and safely. The pressure that comes from compressed air has so many uses in industries.