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Differences Between Reciprocating and Rotary Screw Air Compressors

By In Blog On April 23, 2018

Air compressors are one of the most commonly used machines in the construction, manufacturing, and automotive industries. An air compressor provides power to a wide range of tools, from paint guns to pressure washers to sandblasters. Yet to maximize the results you get from your investment, you must be sure to buy the right kind of compressor for your needs.

Two main styles of air compressor exist on the market today: reciprocating compressors and rotary screw compressors. Wise business owners will take the time to make the right determination when choosing between the two. This article will help to further your understanding of the difference between reciprocating and rotary screw air compressors.

Reciprocating Air Compressors and Rotary Screw Air Compressors         

The distinguishing feature of a reciprocating air compressor lies in the method by which it generates its pressure. Not unlike the engine in an automobile, a reciprocating air compressor utilizes a series of crankshaft-powered pistons. As these pistons move back and forth in their cylinders, they compress the air inside of the tank.

A rotary screw air compressor operates by means of a completely different sort of mechanism. Here, rather than pistons, compression is accomplished through the rotation of a pair of intermeshed helical screws. Often referred to as the rotors, these screws spin in harmony with one another, pushing air into the tank through their movement.

Components and Heat

In addition to the pistons, reciprocating air compressors contain a number of other related wear components. These components include crankshafts, connecting rods, and valves. The sheer number of components involved in the operation of a reciprocating compressor increase its vulnerability to damage and breakdowns.

A rotary screw, by comparison, has a much simpler system. Compression requires only the two rotors that do not come into contact therefore, they will remain largely free of problems. Because the two rotors rotate in concert and do not contact one another, they generate very little heat through friction.

The operating temperature of a rotary screw compressor generally falls between 80 and 99 degrees Celsius. A reciprocating compressor, on the other hand, generates a good deal more internal friction. This friction results in operating temperatures between 150 and 200 degrees Celsius. This hotter environment further increases a reciprocating compressor’s susceptibility to wear and tear.

The greater heat of a reciprocating compressor also means that it will require a more intensive cooling system. Rotary compressors are almost exclusively air cooled — a trait they share with smaller reciprocating compressors. Yet larger reciprocating compressors often generate so much heat that they must utilize a water cooling system.

Such a system brings additional maintenance needs, such as more frequent inspections and repairs.

Pressure and Noise

Reciprocating air compressors hold a key advantage when it comes to the amount of pressure they can generate. The majority of reciprocating compressors are capable of providing up to 250 psi of pressure. Rotary screw compressors, by comparison, generally fall into a range of between 90 psi and 125 psi.

The increased pressure power of a reciprocating compressor comes with one other drawback to be aware of: noise. Compared to rotary screw compressors, reciprocating compressors tend to be much louder, with noise levels often above 80 decibels. Noise can be problematic when working in certain environments and may necessitate the use of noise-isolation equipment.

As you can see, you need to take many different factors into account when deciding between a reciprocal and a rotary screw air compressor. Be sure you have done your research before making a final decision. For more information about which type will be right for you, please don’t hesitate to contact the compressor experts at Compressor-Pump & Service, Inc.

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