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A Buyer’s Guide about Rotary Compressor in the Philippines


When most people think about air compressors, they picture piston air compressors as the primary or traditional design. These machines have been around for decades, and they are known for being relatively inexpensive.

A piston air compressor operates by physically pushing air into a small space using pistons. It then collects the compressed air in a receiver tank.

However, in the current market, we already have a new and improved type—the rotary air compressor.

Despite being more expensive than piston air compressors, these more advanced variants come with numerous benefits. These features make rotary air compressors a great choice for various industries around the world.

What is a Rotary Compressor in the Philippines?

A rotary compressor is a type of compressor that uses either a rotary screw air end or a rotary scroll air end. This variant also has four types based on their rotor design: the screw, lobe, vane, and scroll. Unlike piston air compressors that need large volumes of high-pressure air, a rotary compressor’s process is a continuous sweeping motion, so there is minimal pulsation or surging of flow. Aside from that, rotary air compressors are a lot quieter and produce cooler air that is easier to dry.

Rotary compressors have been popular since the 1980s, with the twin as the most common type. In the this variant, two mated rotors mesh together to trap air and reduce the air volume along the rotors. These units are usually used in sizes ranging from 5 to 900 HP and are available as lubricated or oil-free, depending on the air purity requirements.

Currently, rotary air compressors are the industry standard in plant air compressors. They vary from about 25 to 300 HP and are expanding into smaller and larger markets.

Here are the advantages of using rotary air compressors:

  1. Rotary air compressors can operate continuously and experience little to no downtime with their nonstop airflow and pressurization. They generate less heat and do not have to cycle off to maintain the machinery.
  2. The design of rotary air compressors drives down maintenance costs whilst effectively function at high speed and handle large quantity of fluid.
  3. Rotary air compressors have extremely high airflow rates, making them efficient for running heavy tools and equipment.
  4. This type of air compressor can operate in extremely high temperatures.

What are the components of a rotary compressor?

Before knowing how rotary air compressors work, you first need to identify their different components. These parts are the following:

  1. Air end – The heart of all air compressors. This is the part of a rotary air compressor in which the air is compressed. During this process, air enters the air end through an inlet valve where it is mixed with oil.
  2. Air filter – This component is essential as it affects the longevity of the rotary compressor. The air filter must be suited to the environment and the required airflow. This can also be mounted directly to the compressor. For remote mounting, it can be connected with an air intake hose.
  3. Primary separator tank – This acts as an oil reservoir used as a defense mechanism against oil and gas mixture. When compressed air leaves the air end, it is mixed with compressor oil. This mixture will enter the primary separator tank where the first separation of oil will happen.

The primary separator tank utilizes mechanical separation and centrifugal force to drive oil molecules together. This process will form droplets that will fall to the bottom of the tank, and the oil amount will then be removed from the air.

  • Secondary separation filter – Also known as coalescing filter, this component includes a membrane material that gathers all remaining oil particles and circulates them back into the main oiling system. This separation filter can be attached to the primary separation tank or mounted on its filler manifold remotely.
  • Oil filter – This part is essential due to the rotary air compressor’s closed-loop oiling system. The oil filter is responsible for collecting any loose particles that have been collected in the oil, which should not re-enter the rotary air compressor.
  • Oil cooler – This can be used together with the engine’s cooling system, or it can be a stand-alone air-to-liquid cooler. The process of air compressing generates a lot of heat, which warms up the oil. This heat must pass through a cooler before it is circulated back to the compressor.

The oil cooler has a liquid-to-liquid version that needs a sufficient cooling capacity to lower the temperature of the compressor oil and the engine cooling. The air-to-liquid cooler, however, will need clean, cool air to keep the oil in its optimal temperature range.