Choosing the right rotary screw compressor

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Rotary screw compressors come in all shapes and sizes. And with different features. So what are the screw compressor technologies that matter? And which will serve you best?

Let's start with the beginning: the rotary screw compressor itself. This air compressor type is in extremely high demand. That's because it combines many characteristics that make it a great fit for a variety of industrial and professional applications.

Here are just a few that set screw compressors apart from other types:

  • Low energy consumption: The best rotary screw compressors use less energy to produce top quality air. As a result, they can greatly lower operating costs.
  • Convenient operation: Rotary screw compressors can reliably provide a continuous air supply. In addition, they are designed to deliver very high airflow rates.
  • Easy to maintain: Because they have fewer parts, there is much less need to service these compressors. This, in turn, means that the best rotary screw compressors drastically reduce maintenance costs.
  • Outstanding safety: Rotary screw compressors are safe to operate.
  • Reliable performance in tough conditions: The best rotary screw compressors deliver an outstanding performance in tough environments, such as high temperatures.
  • Quiet operation: Although they deliver large air flows, rotary screw compressors run more quietly than piston compressors. That means they can often be set up close to the point of use. This saves on piping and on floor space in the utility room.
  • Longer lifespan: The best rotary screw air compressors are built to last and excel with long service lives. 

What are rotary screw compressors used for?

All of these attributes make rotary screw air compressors the optimal solution for professional and industrial applications, often with a continuous air demand. For example, you can find them in food packaging plants, automated manufacturing systems, but also in workshops.

Rotary screw air compressors are not just popular as stationary models. Mobile units, for example those mounted on trailers, are used on construction sites to operate pneumatic tools, or sand blasting and painting systems. In addition, due to their ease of installation and robustness, they are an excellent fit for mining operations in remote locations.

Selecting the right screw compressor technologies

Rotary screw compressors are a great fit for a wide range of applications. However, to take full advantage of everything they have to offer, it is important to select the right screw compressor technologies.

With many different types to choose from, it depends on what rotary screw compressors are used for in your operation.

Let’s take a look at your different options in screw compressor technologies. 

Drive type

First, you have to select the kind of drive you want in your compressor. You can choose between a belt drive, a gear drive or a direct drive.

Rotary screw compressors with a belt drive are robust, easy to install and to maintain. These features, in combination with their low investment cost, make them an excellent choice for smaller operations.

The use of gear drives allows rotary screw air compressors to operate more quietly. This means they can be installed close to where people are working without violating any noise standards. Although their initial investment cost is higher, compressors with gear drives are more efficient, which reduces their operating costs.

The best rotary screw compressors you can buy are those with direct drives. They are very efficient and offer superior performance. In addition, they are even quieter than the other versions. 

Oil-free or oil-injected?

Oil free piston compressors - cleanAIR

The next decision is about whether to invest in an oil-injected or an oil-free compressor. In the case of the former, lubricating oil is used to help compress the air. This technology allows users to achieve a higher pressure. In addition, it is more efficient. However, because these pressure compressors introduce oil into the process, the air is less clean.

Oil-free compressors, on the other hand, produce a higher quality compressed air.

As a result, an oil-injected rotary screw air compressor is often the better choice when the quality of the air matters less. For example, this is the case when powering pneumatic tools.

An oil-free rotary screw air compressor, on the other hand, is the best rotary screw compressor for applications when air quality is important. This is the case in the food & beverage sector, medical research, the pharmaceutical industry or in semiconductor manufacturing. 

Fixed speed, variable speed drive or iPM

Ceccato Screw Compressor DRE 100

Energy takes up more than 70% of owning and operating a compressor. Fortunately, Variable Speed Drive (VSD) technology is available to significantly reduce your energy use. Your net result: lower operating costs and a smaller emission footprint.

Here's how VSD works. Traditional rotary screw compressors are fixed-speed. They are either off or on. If you have a production environment with a very stable compressed air demand, a fixed-speed compressor will be a good solution for you. However, if your air use fluctuates, a compressor always running at 100% will waste a lot of energy. Variable Speed Drive compressors adjust their motor speed to follow your air demand. The result: up to 35% energy savings. iPM VSD compressors do even better. In part thanks to their Interior Permanent Magnet motor, they can save up to 45% in energy use and costs.

VSD and iPM compressors come with a higher investment cost. However, this is quickly recouped thanks to the energy savings they generate. Your Ceccato representative can help you calculate whether a VSD or iPM compressor is the right solution for you. Their simulation based on your current compressed air use will show how quickly you can achieve return on your VSD or iPM investment. 

Got questions? We have answers

Still not sure what rotary screw compressor technologies are the right fit for you? Then contact Ceccato and our experts will assist you with any questions you may have. We're happy to help!