Types of Rotary Screw Compressors

Why are we the ultimate rotary screw compressor service provider?

 

 

Here at Disco, we have earned the trust of our customers by our personal, service oriented approach to rebuilding screw compressors. Everything that comes out of our shops, has been serviced for maximum energy efficiency, easy maintenance, and above all reliable performance.

 

Our specialists continue to take advantage of the state-of-the-art machining innovations and refining industry techniques. With extensive commitment to development and research, we are able to keep our products and services on the leading edge of technology to benefit our customers.  Screw compressors and their applications have changed in the 25 years that we’ve been rebuilding them, and so has our approach to servicing them.

 

We are committed to maintaining and implementing the most prominent quality standards. In other words, we aim for excellence in all that we do.

 

And we succeed because we assist our customers:

 

Save time!

 

Save money!

 

Make informed decisions!

 

Get their screw compressor turned around fast!

 

What are the types of rotary screw compressors that we service?

 

There are two types of rotary screw compressors. These include oil-injected rotary screw compressors and and oil-free rotary screw compressors.

 

We service both types.

 

Oil-injected rotary screw compressors.

 

How do oil-injected screw compressors operate? As the name suggests: oil is injected in the compressor element (this is where the actual compression occurs) during the air compression. The oil separator later removes the oil, so you will end up with clean, compressed air.

 

Although 99.9% of the oil is retained in the compressor, a little oil passes through the separator and leaves the compressor together with the compressed air. This is referred to as “oil carryover.”

 

Therefore, this type of rotary screw compressor does not produce oil-free air and cannot be employed in fields where oil-free air is required. But for a majority of machinery, workshops and factories, the minor oil-carryover of the compressor is not problematic. In fact, it assists in rust prevention and helps in running the machine smoothly.

 

Oil-free rotary screw compressors.

 

The other type of rotary screw compressor works similarly to the oil-injected compressors, only that there’s no oil, only air. Since there’s no oil injection during the compression, two stages are involved in the compression process. If the air is compressed from 1 to 7 bars without a cooling period, it will become extremely hot. If you require a large amount of 100% oil-free air, this would be the best compressor to go with.

 

The first stage involves the compression of the air a few bars (say 2 to 5 bars). The air gets very hot through this stage, so it is passed through an intercooler before entering the final stage. The final stage involves further air compression from 2 to 5 bars to the final level, which is commonly 7 bars. Usually, the two phases will be built on the first gear box, with one motor driving them at once.

 

What makes us stand out from our competitors?

 

Once all of the parts of your rotary screw compressor are repaired or replaced and we are satisfied with the quality of work done, your rotary screw compressor will be tested in order to ensure maximum work quality. The first step is to dynamically balance the rotors and assemble the compressor with proper head clearances with all flanges blinded for pressure and vacuum testing.

 

The final steps in the process of repairing your rotary screw compressor are to vacuum test the compressor to maximum vacuum achievable and hold that vacuum for a minimum period of 20 minutes. Then the rotors are pressure tested to 110 psi for a period of 20 minutes. If there are no leaks within the rotors, then the blinds are removed and the ports are taped off in preparation for shipment.

 

What is the difference in the types of rotary screw compressors?

 

The rotary screw compressor is presented in oil-free and oil-injected versions. The elementary principles are similar, rotors push air to one inclination, but it is an entirely different device.

 

The big difference is the compressor elements design, the section where the actual compression occurs. The oil-injected variety requires oil to operate properly, while the oil-free type doesn’t require any oil to run.

 

Due to this, the rotors employed in oil-free screw compressors have superior qualities with minimal space between them. These compressors don’t touch each other or else they would wear off too fast. However, oil-injected models are the most common type of rotary screw compressors.

 

They are employed for particular and peculiar instructions. They can be used in big food plants, oil/gas or chemical refineries or other fields where the compressed air must be 100% oil free.

 

Contact Disco if you have any questions about how your rotary screw compressor is operating and if you may need to bring it in for servicing.