Air compressors can be used in a wide range of industries and applications. In this article we want to show you the different types of (industrial) air compressors that MARK has to offer, and their specific properties. That way you have an idea of which type of compressor might be best suited for your specific situation.
Air compressors create compressed air by drawing in environmental air and pressurising it. Air treatment systems clean the air during the process, resulting in clean pressurised air suitable for a wide array of applications.
How exactly air is compressed depends on the type of compressor.
The piston air compressor (or reciprocating compressor) is the oldest and most common type of compressor. Piston compressors are often the first compressor to buy when just starting out. The mechanism works as follows:
Essentially, a piston compressor contains a valve system and two valve discs. When the piston moves down, it draws air into the cylinder. One of the valve discs folds downward, allowing the air to pass. When the piston moves upward, the large disc folds upward also, and closes. The compressed air is then delivered to the end process. Essentially, the mechanism is that of a - small - combustion engine, like the ones that are used in cars.
Piston compressors are available in different configurations. For instance, there’s a difference between oil-free and oil-lubricated compressors. Read more about this difference at the end of this article. There are also single-stage, two-stage and multi-stage piston compressors. This last type of piston compressor contains an extra step where the air is compressed a second, third or even fourth time.
Although piston compressors are available in lots of different configurations, they are most commonly used in:
Generally, a piston compressor offers the following advantages:
Instead of a valve system, this air compressor uses rotors to compress air. Male and female rotors turn in opposite directions, thus trapping the air between them. This causes the volume of the air to be reduced. The compressed air can then immediately be used in different kinds of applications. The rotary-screw compressor does not have a valve system: therefore the risk of mechanical unbalance is reduced. This type of air compressor can be operated at high air flow rates.
There are 3 different types of screw compressors:
Rotary-screw compressors can be used in the same industries as piston compressors. In many cases, they replace them because of their higher capacity and the fact that they can deliver a constant air flow. Some industries specifically require a constant air flow, like the:
Both the piston compressor and rotary-screw compressor come in an oil-free and oil-lubricated version. In the latter, oil is mostly used to lubricate, seal and cool the compressed air. In oil-free air compressors, the same is achieved through different means, for instance pre-lubricated cylinders and an intercooler.
It is important to first figure out the exact process the air compressor will be used for. In some applications, even the slightest risk of contamination is not to be taken. For instance:
In these industries, oil-free air compressors offer an elegant solution. They weigh less and there is obviously no contamination risk.
However, in some - smaller - processes, oil contamination is not an immediate issue. It might be wise to make use of an oil-lubricated air compressor, since they have less maintenance requirements, have a longer life span and produce less noise or heat.
Whether you need oil-free or lubricated compressors depends heavily on your needs and sector.
As you can see, the most obvious difference between both types of compressors is that rotary screw compressors can deliver a continuous airflow, while piston compressors cannot. But if you don’t need a continuous flow of compressed air, you might still be faced with the question: ‘What type do I choose?’. Everything depends on the volume capacity, maintenance and noise requirements that are integral to your industry. MARK helps you find the right compressor for your specific goals.
What type of air compressor you need, depends on a number of factors. Generally speaking, the following applies per sector:
The size is definitely a determining factor in choosing an air compressor. If it’s too small, you’ll waste time while waiting for the right pressure. If it’s too big you’ll waste your resources and won’t be able to move it around when necessary.
Size can mean two things: mainly the actual size of the system (the physical size) and install size (measured in horsepower).