Ingersoll-Rand air compressor oil question

[help_please]

Hello,
I am an electrician, but I am now having to work on
mechanical industrial equipment.
My Question is this, I had to change the oil on a
small air compressor at work (Ingersoll-Rand, two stage
reciprocating, max psi 175) and I found what I thought
to be a large amount of sludge in the bottom of
the oil pan (actually the frame) it was about 3/4"
deep and gray, oily, and it appeared to be almost
metallic, is/was this supposed to be there, was it
put there by the factory, or is it what I think
it is and it is just sludge.
I drained the oil and then tipped the compressor
on its side for 2 days to let it all ooze out
of the fill, sight glass and drain ports. Then
after I looked at it I thought, gee I hope that
was not supposed to be in there on purpose for
lubrication or heat dissipation. I don't know
much about air compressors.
Any help would be greatly appreciated.
Rick M.
5 SEPT 15

 

[JR]

Don't remember that with the one at work. A few monthly ago we found it to be 2+QTS low. It was like pulling teeth to get them to let me drain and refill. Maintenance at the shop is nonexistent. Labor cost to high, no common sense.



-harvey

 

[MolaKule]

What you described sounds to be mostly sludge from the sump or oil pan.

In the compression process, a lot of air is (which contains moisture) is drawn into the lubricant. This moisture mixes with the oil and due to oxidation and the heating and cooling cycles, forms sludge.

Metal wear particles get mixed with the oil and agglomerate to form the gray to black sludge.

If there was that much sludge, you may have to change the lubricant again fairly soon.

 

[Shannow]

Molakule nailed it.

Seen exactly that in some big reciprocating compressors, particularly if the duty cycle was low (e.g. system upgrades and expansions included screw compressors, which had unloaders/more efficiency, and the recips were only run weekly to check that they were there).

Clean it out good, as if it gunk comes apart, it can be unpleasant for the machine.