Meaning and Types of Pressurized Air (COMPRESSOR)

As we know, Many of us are already familiar with the compressor machine. Yes! This tool is widely used in daily life. To understand more clearly, please read the following article!

A compressor is a device/machine that functions to compress or increase the pressure of air or gas fluid or to transfer gas fluid from a low static pressure to a higher static pressure state (Anwar, 2010). In my personal opinion, a compressor is a tool used to increase the air pressure capable of compressing pressurized air into a storage tank. Further understanding of compressors reveals that there are two types (dynamic compressors and positive displacement). To distinguish and deepen the reader's understanding of compressors, allow me to share a little about what compressors are, their functions, and how they work. For those of you who are curious, please read the following review.

A. Definition of Compressor

Perhaps many readers are wondering what a compressor actually is. By definition, a compressor is a mechanical device used to compress/collect gas or air into a storage tank so that it has a higher pressure. As mentioned earlier, there are two types of compressors, namely positive displacement compressors and dynamic compressors. Dynamic compressors consist of centrifugal and axial compressors, while positive compressors consist of piston and rotary compressors. Compressors are used to maintain the resistance of suction in a space by continuously drawing in air in a closed space.

B. Type of Compressor

Reciprocating Type Compressor
Single Stage Piston Compressor
The air that is sucked in the atmosphere will be compressed using a single stroke, the downward movement of the piston makes the air pressure lower than the pressure outside the atmosphere, thus causing pressurized air to be sucked into the cylinder through the inlet valve. In the end, the piston moves upwards, the inlet valve closes (due to cylinder pressure) and the pressure in the cylinder increases and forces the outlet valve to open to enter the supply tank (air reservoir) as a pressure storage medium.

This type of compressor is often used in systems that require operating pressures between 3 BAR and 7 BAR.|

Two Stage Piston Compressor
Piston Single-Stage Compressor, when the air is compressed uniformly above 6 BAR, it will produce excessive heat, thus becoming inefficient. For industrial use that requires the performance of a continuous compressor system (continuous standby), a two-stage compressor type is needed. Its performance steps are similar to a single-stage compressor, but with the addition of one more step after the cooling stage. In the first step, compression is done at 3 BAR pressure, then the second stage (cooling) is carried out, and then continued to the third step by compressing the pressure to 6 BAR.

The low temperature entering the pressure cylinder in the second stage can improve the cooling efficiency compared to a single-stage compressor. The final temperature may be around 120°C after the cooling process.
Rotary Type Compressor Rotary Sliding Vane Compressor This type of compressor has a motor section fitted with an eccentric that positions the blades to be able to move within radial slots. As the rotor rotates, centrifugal movement can keep the blades in contact with the stator wall and the space between the blades, positioning the air inlet channels so that the compression step occurs. Pressure sealing through lubrication on the compressor air rim is achieved by injecting oil into the rim. In addition to acting as a sealant, the oil also serves as a coolant.
Screw Compressor Twin-screw helical rotor compressor," which operates by having two helical rotors rotating in opposite directions. The space between the two rotors decreases axially, compressing the air trapped between them. Additionally, the incoming oil flow provides lubrication and sealing for the space between the rotating screws. The oil separator functions to remove oil content from the compressed air. This type of compressor can generate air pressure up to 10 bar, making it more efficient than vane compressors as it can provide continuous pressure.