Rotary screw compressors are just one of a variety of air compressors. They employ a rotary type positive expulsion system, which conveys pressurized air to power drills, pumps and other types of machinery. Rotary screw compressors, also known as positive displacement compressors, deliver a determinate amount of highly pressurized air.

Rotary screw compressors contain the following components, all enclosed in a sealed case: the compressor unit, systems that maintain proper lubrication, proper temperature control, proper capacity control and the system that cleans the discharged air. Inside of the compressor unit itself there are two interlocking corkscrew-shaped augers or rotors. Each auger or screw has a wide end and a narrow end. The wide end of the screw is the inlet that allows free air to flow into the screw housing upon demand, helped along by the partial vacuum caused by the screws rotating inside the housing.

The air and oil combination flows downward from the wide ends to the narrow ends of the screw. This increases the vacuum, pulling more air into the housing. As the mixture is pulled downward through the grooves of the auger, the space where the air was narrows. At the narrow end of the screw, a valve tunnels the condensed air and oil into a separator, removing as much oil as possible from the condensed air. It is then released into the compressor receiver.

Rotary screw compressors are available in oil cooled and oil free. When comparing the oil cooled model to the oil free model, the procedure for compressing the air is basically the same, although the medium in which the procedure is carried out is different. One is performed in an oil filled chamber which provides coolant and sealant properties. The byproducts of the oil filled units are gas and oil instead of air and oil, which are the byproducts of the oil free systems. Oil free rotary screw compressors work the same except that in the absence of the oil the process does create higher temperatures and it is less energy efficient.

When choosing a rotary screw air compressor there are some important things to remember and take into consideration. What type of project are you working on? Does your compressor need to be transportable? Do you want oil cooled or oil free? Many consumers report that rotary screw compressors are easy to maintain and have a long life. They are known for their above average production abilities in a small package.

Using compressed air as an efficient kinetic energy resource requires a simple machine and holding tank. All compressors will have the same basic parts: receiving tank, pressure gauge and compression machinery. The identifying difference between two-stage and single-stage compressors is the number of compression cylinders incorporated.

Single-stage air compressors follow a few simple principles. When the compressor’s piston is actuated it literally squeezes the air contained inside its cylinder until the PSI is strong enough to release a one-way valve connection between the cylinder and the receiving tank. As the piston cycles, the receiving tank is filled with compressed air. A pressure switch is located on the receiving tank to regulate the tank's maximum PSI with a mechanical relief valve attached for safety purposes. When the set maximum air pressure is achieved in the tank, a switch connected to the pressure switch will signal the motor to turn off. The pressure inside the receiving tank is continually monitored by the pressure gauge. When the PSI in the receiving tank drops below a preset level, the pressure switch will activate the motor to add more compressed air to restore the overall pressure of the receiver.

A two-stage air compressor follows the exact same principles as the single-stage but there are two actuating pistons. The first stage will produce compressed air at a lower pressure than is ultimately desired for the end use. As the pressure in the first receiving stage builds it supplies air to the second stage's cylinder. The air is again compacted before being released into the output receiving tank. The advantage of a two-stage compressor is that it distributes the work load between two components to achieve a higher level of compressed air without having to overwork a single piston. The higher PSI offerings of two-stage compressors make them the better choice for industrial use and high torque pneumatic tools.

A single-stage compressor is a highly efficient machine. Choosing an oil-less type will ensure long use with little maintenance required. The disadvantage to a single stage compressor is that its output is limited to providing air below 125 PSI.

Two-stage compressors require slightly more maintenance because they have more parts. The advantage is that greater PSI offerings can be efficiently maintained without over-exerting the machine. Two-stage compressors also generate less heat than single-stage compressors do, which means that parts may not wear out as quickly and your compressor will likely have a longer life.

Industrial air compressors are a great choice for those that need compressed air in many separate areas of their business at once. While portable air compressors are useful for small jobs, a well placed, well connected industrial air compressor can offer significant increases in productivity. This is due to their increased pressure allotted over portable models and the ease with which a worker can obtain compressed air from the network of pipes that are connected to the stationary unit.

When deciding to install a stationary industrial air compressor, it is important to note a variety of factors that could impede performance or degrade the components of your unit. Appropriate placing is important for a variety of these factors. A well placed unit should first have access to enough actual cubic units of incoming air flow. This amount varies from unit to unit, but a standard 1000 cubic feet of air flow per 5 hp of the compressor's motor rating is necessary. When placing the unit it is also a good idea to make sure the motor and functional parts are placed to allow for easy maintenance access.

Temperature is also important to be aware of as temperatures below 32 or above 100 degrees Fahrenheit are conditions where the compressor could be under undue amounts of stress, leading to early malfunction. Dust and humidity present in the air can also be an issue, as any humidity in the air is transferred through the air compressor being used by the workers, potentially causing problems. Dust can be another factor in the early degradation of compressor parts.

Lastly you should consider noise when placing your unit. A poorly placed air compressor can severely impede work performance for those that are subject to it's noise. Reviewing local statutes on noise limitations and discussing placement with an experienced compressed air vendor is a good idea before placement.

Effective placing will prevent the compressor from shaking too much and will prevent any unnecessary maintenance in the future. Finally, consider the use of floor dampeners along the anchoring areas of the unit to further reduce noise, vibration, and any possible damage to the floor or your industrial compressor unit. Units that do not use floor dampeners can create unnecessary stress on the unit due to vibrations. By using these floor dampeners, not only will the compressor be relieved of stress, but the sounds of the industrial air compressor will be muffled to a peaceful hum.

If your business requires an industrial air compressor, then you have two options: you can buy a new air compressor, or you can buy a used one. While it may be very tempting to buy a new air compressor, there are many advantages to buying on that has been used.

One of the biggest advantages of buying a used air compressor is that it can save your company thousands of dollars. A well-maintained used air compressor will make your work much easier and reduce the amount of time needed for a task. Because of that, your company will have more time to focus on other tasks, allowing you to finish them more quickly, and therefore completing jobs faster than before. The return you make because of your used air compressor can quickly make up for the investment you spent on it, much more quickly than that of a new air compressor.

Additionally, a used air compressor will frequently still be under warranty from when it was first purchased. As long as the warranty is still good, fixing broken compressors should not be a problem. Many used air compressors are sold by business owners that had cared for it originally, owners who knew how to take care of their equipment. This means that many used air compressors are in great condition, and can easily compare to new air compressors.

When you are looking for a used air compressor, certain things should be taken into consideration. You should always make sure the air compressor has clean, working parts. Check inside the compressor for sludge build up, missing parts (like pistons, hoses, and rings), and to see how well it has been taken care of. If there are a lot of scratches and dents on the body of the compressor, its parts may be damaged as well. If the compressor you are thinking about buying needs repair, figure out how much money will be needed to repair it. It could be worth the investment to buy an air compressor that needs a little fix, because it may still be cheaper than buying a new air compressor. If the seller is asking too much money for it, try negotiating. Many people who sell used industrial air compressors have no idea how these machines are valued, and may be unaware how much repairs may cost. Negotiating is a great way to get a more appropriate price.

Buying a used air compressor can be a better decision than buying one brand new; however, it is important to be careful and know what you are buying. Do your research before making the purchase, and you will be sure to make the right decision.

Moisture can run through an air compressed air system’s hoses and into the unit, which can cause damage that can be quite costly, especially from repairs. Fortunately, refrigerated air dryers are units that remove moisture from compressed air systems. In order to maintain a compressed air system, installation of an appropriately sized refrigerated air dryer is necessary.

A common entry point for moisture is the air compressor’s inlet air filter. Standard air compressors can convert seven cubic feet of air to 100 psig per single cubic foot, making any water vapor in the air also compressed to that size.
Water that winds up contained in compressed air comes in different forms, including liquid, mist and vapor or gas. A general purpose filter can be used with a compressed air system in order to remove the liquid water within the system, with the remaining water that is either a mist or vapor being removed by the refrigerated air dryer.

Refrigerated air dryers also prevent equipment contamination located downstream from the air compressor. Water contamination can cause moving parts to fail, with the holding capacity of moisture in the air reduced by fifty percent when the air temperature drops at fifty degree levels. This can lead to costly repairs.

The refrigerated air dryer’s process begins with the use of an air-to-air heat exchanger, which first cools the compressed air. The heat exchanger condenses small amounts of moisture by pre-cooling incoming air and sending it to an air-to-refrigerant exchanger, which is cooled even further by use of a liquid refrigerant. Remaining moisture is condensed into a liquid that is drained out of the system. Air is finally heated inside the heat exchanger to prevent the hose’s pipe from sweating.

When searching for the right refrigerated air dryer, keep in mind of the pressure dew point. The pressure dew point is a temperature required in order for water vapor or mist to condense into liquid. The type of pressure dew point class most often used is a Class 4. In order to determine the pressure dew point class and temperature requirements, have a test of equipment performed.