Atlas Copco Air Compressor Problem

I can't quite see the 24mm bolts that it has being trying to pass from here, but they might be causing the damage, perhaps.

Yes.

Maybe.

Many unknown issues seem to be confronting you.

Like who in the company knows anything about your air compressors.

Like where the operator's manual has disappeared to.

Like locating the trouble shooting guide within the missing manual.

Where the Atlas Copco web site is to look for manual/trouble shooting guide that is surely published there.

Where the telephone number of Atlas Copco might be. (Try the web site)

The identity of the local service company that works on compressors.

Good luck.

Did you increase the rpm to get higher output? If so, did you check with Atlas Copco that it would be OK? Have you maintained it properly for the 4 years?

Compressors are a funny animals, they will run and run when used with in their designed parameters. Get out of the parameter just a bit and boom they break. Companies do them selfs a disservice by not doing air use surveys from time to time. Not by sending a millwright or someone else that does not know how to do this type of work, but hire a competent firm to do this. From the data that is gained you can then make the added adjustments to equipment or add equipment as needed to meet the demands of the facility. Randomly changing the operating parameters gets you into the issues you are seeing here.

Fixit

Generically speaking it sounds like small pipework and increased back pressure is not a good mix

Zubair,

Please check some answers in Mechanical Thread

"Compressor operation below dictated RPM"

There are several other operating conditions you should specify in order to get a good answer. Such things as output volume (cfm), output pressure psi or bar, ambient air temp, output/inlet air temps, input air humidity, any strange things with the oil, any anomalies in the maintenance records, etc. Most important though is what is the type of damage to the screw gear? A few of many possibilities include worn bearings, insufficient oil circulation, over temp., over speed of the screws, or too humid inlet air among many others.

The GA 37 VSD (variable speed drive) FF (front control?) is rated at a minimum 1870 rpm and a max of about 5800 at 13 bar/175 psi so the increased speed shouldn't be the root source of the problem. The motor is 37 kw/50 hp motor. It is also possible that with usage of 4 years it may simple need servicing, especially if this has historically been lacking.

Have an Atlas-Copco factory authorized service repair shop send a service person, familiar with your model, out to your site and have him decide what the problem is. Although their rates may be higher they are usually more efficient with their diagnosis than general shops. Air Compressors are difficult to diagnose it you are not there to look at various parts, hear the operation of it, look at the readings on the control panel, feel for vibrations, check the input voltage and current and other parameters.

Some "old timers" can tell a lot about machinery simple by listening to it operating under various loads and feeling for vibrations.

Good Luck, Old Salt

Check Filter, or have you replaced filter/drier lately? is it done cleanly?

Some foreign particles might have dislodge in between screw contact surfaces. Or its cause of failure is just by material fatigue, for 4 years service it may happen.

Load could be one root, rpm is directly proportional to frequency in contact sealing surfaces of screws. Increase of heat is one way to cause material fatigue.

Damage to the screw suggests ingress of contaminants (in the oil and/or the air) and/or lack of oil and/or collapsed bearing(s) made worse by running faster maybe to compensate loss of output due to wear-and-tear, noticeable to the expert ear, but if not remedied, then suddenly becoming obvious, even to the novice.

GA37VSD is Variable Speed Drive..FF means Full Feature...which means it has inbuilt dryer(usually refrigerant style)...you do not mention hours machine has run?..has machine been serviced regularly..has air end seized?...you are into big bucks if it has....have you a machine serial number?....only kluber synthetic grease recommended for motor...that will be next issue if machine has done lots of hours...motor also needs bearing changes at around 50k...specially if no greasing bearing programme has been run....