Air compressor is an important component that exists in the factory and workshop. It is a portable machine with a single-engine that utilizes air pressure to power a variety of tools such as nailers, paint sprayers, impact wrenches, sanders, est. It converts electrical power into kinetic energy. Air compressor does not only support the operation of drilling or sandering work, it can also be used for inflating a tire or unclogging the sink. The key advantage of using air compressors is that they don’t require their own motor to run and are much more powerful than other regular tools. It only requires little maintenance of adding a bit of oiling. There are many different types of air compressor and it has its own features. We will introduce a few common types of air compressor and their functionality in more detail.
How Air Compressor Works?
The power energy is generated by forcing air into a storage container, pressurize it until reaching the engineered upper limit then the machine will shut off, the energy stored in the pressurized air can be used for powering the tools. As it is released and the container depressurizes until it reaches the lower limit, the air compressor will turn on and re-pressure again. There are three levels that classify pressure delivered by the air compressor. Low-pressure air compressor possess a discharge pressure of not more than 150 pounds per square inch (PSI), Medium pressure air compressor has a discharge pressure ranging from 151 to 1000 pounds per square inch (PSI), and High-pressure air compressor can have a discharge pressure of more than 1000 pounds per square inch (PSI).
There are two methods to achieve air compression which are positive displacement and dynamic displacement. Both methods are relatively similar but it varies on the way of achieving the process. The positive displacement is forcing air into the chamber where the volume is decreased to compress the air and generate potential energy. There are three common types of air compressors that using positive displacements which are Rotary Screw, Rotary Vane, and Reciprocating/Piston Type. Dynamic displacement is using a rotating blade to generate the airflow. The air is restricted to create pressure and the kinetic energy is stored in the compressor. Dynamic displacement compressor is mainly used for large industrial projects such as chemical plants. There are two dynamic displacements which are Axial Compressor and Centrifugal Compressor.
We can classify the air compressor with the design and principle of operation. There are three most common air compressors: Reciprocating compressor (Single-stage/Two-stage), Rotary-screw compressor, and Centrifugal compressor.
1.Reciprocating Compressor (also known as Piston Type)
Reciprocating Compressor is not designed for continuous use and it is normally used for small worksites such as home construction projects and garages. It is using pistons driven by a crankshaft to deliver the gas at high pressure. A reciprocating compressor is having more moving parts than the rotary screw compressor and these parts are lubricated with oil for smooth operation. There are two types of reciprocating compressors: Single-stage and two-stage. The single-stage compressor is much more affordable and commonly to be used in many mechanic shops. The air will be compressed on one side of the piston in the single-stage compressor. Air is drawn in when the piston is moving down, the air will be compressed when the piston is moving up. A two-stage compressor can provide greater efficiency as it has two compression chambers on each side of a piston. It can provide a better cooling system than other types of compressor, but it is high in cost and make it suitable for factory or workshop.
2.Rotary Screw Compressor
This is the easiest compressor to take care of and with the least maintenance, it is typically large, available in industrial-size, and suitable for long-term continuous usage. The rotary screw compressor consists of two helical screws that rotate constantly in an opposite direction and compress the air between the screws. It comes lubricated with oil or runs oil-free. It is equipped with an internal cooling system and power ranging from 5 horsepower (HP) up to 350 horsepower(HP).
3.Centrifugal Compressor (also known as radial compressor)
It has a rotating impeller that brings the air into the center, the air will then be pushed forward through the centrifugal. A diffuser will slow down the flow of air in order to generate kinetic energy. Due to its multi-phase compression process, it can reach around 1,000 horsepower (HP) and produce a high volume of energy in a relatively small machine. One of the common applications of centrifugal compressors is the HVAC system, it also typically used for factories such as chemical plants, steel manufacturing factory, and any large applications. Centrifugal compressor requires less maintenance than the reciprocating and rotary screw compressor.
What other factors need to be considered when choosing an air compressor?
Firstly, you will need to consider whether to use oil-based or oil-free lubricated compressors. An oil-based compressor requires regular maintenance of adding oil to the piston. Whereas oil-free compressor is in a compact design and requires fewer parts to operate. It tends to be less weight and cheaper than the oil-based compressor. But in terms of the useful life span, the oil-based compressor is more durable and stronger than the oil-free compressor. An oil-free compressor able to heat up faster to a higher temperature but it will create more noise when operating it. It is not advisable to use an oil-free compressor if you want a less noisy working environment. The oil-free compressor is popular for small-scale works, home use, or some industries such as food & beverage, dental, or pharmaceutical industry where there is a necessity to avoid the products get contact with oil. The oil-based compressor is suitable for heavy-duty works in industrial or commercial use as it is versatile, robust, and able to operate for long hours.
Secondly, whether you need the compressor equipped with a variable speed or fixed speed. A variable-speed compressor is able to automatically adjust the motor speed based on the demand for air. It contains a technique that controls the speed of the motor and amount of air compression, allows us to manage the power output. The fixed-variable compressor provides a constant and continuous stream of power to the motor and maintains a certain frequency in the air compression job. Fixed variable tends to be cheaper than variable compressor as it is less efficient and not energy saving. If you choose for variable speed compressor, it will cost you high initial capital and the maintenance fee also tend to be more expensive than a fixed-speed compressor.
To choose a suitable air compressor for your project, you will need to consider the application of the compressor, and ask whether continuous operation used in a large industrial factory or use sporadically? Also, consider the budget of initial cost and related ongoing operating or maintenance cost. MecHero Malaysia supplies different types and applications of the air compressor to meet your industrial requirements. You can always contact us at +6011-7000 7687 or email us at my.mechero@gmail.com for the inquiry about the types of air compressor cover in Malaysia. We also supply a wide range of steel material, hardware, or mechanical components. Tell us your requirements now and we can advise you accordingly.
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