We are thinking of moving from a piston air compressor to a rotary screw compressor for our BHO process. Has anyone had any experience with this type of compressor?
I’m concerned of the Oil in the air due to the screws being lubricated.
Also, I’m not sure if this applies to all types, but the air is moved through a wet tank then dried. What’s up with that?
is your air pump driving a haskel or something similar?
you’ll want an oil separator.
Duel Haskels.
The one I may be looking at has one internally. Have you modified or added one to a rotary compressor before?
personally I would recommend Ingersoll screw compressors, great reliability, and customer service. here is a basic diagram of a proper screw comp. setup.
Nice. I appreciate you and I’ll definitely be looking in to this set up.
There is such a thing as an oilless screw compressor as well.
All compressors that are worth a shit use oil for lubrication and will pass some nonzero amount of that oil into the compressed air stream. “Oil-free”/“Oilless” systems are louder, wear out faster and create more heat for a given amount of air, which means they need more treatment after the compressor to get the air fully dried out and clean.
Rotary screw compressors (at least, most of them) pressurize the wet tank and that pressure is used to push oil through a metering device and inject on the inlet side of the rotary screw. Most rotary screws have fairly tight tolerances and if not kept oiled will gall the mating screws or trash the bearings those screws rotate upon.
The wet tank usually incorporates some sort of seperatory mechanism and/or filter as well as the lubricating oil reservoir. There shouldn’t be a lot of oil making it past that separator filter, but regardless of how much it’s not a bad idea to put a coalescing filter between the compressor and what you are trying to drive with that compressed air.
There’s also refrigerated compressed air dryers that ensure the air stream is cooled significantly before passing the air through a dryer, so that the maximum amount of water that can be condensed & filtered out is eliminated before it gets into your air driven appliances.
You said it all… thanks @greenbuggy
@RawZebra do put additional filtration, but don’t worry too much about the last little bit of oil coming out of a wet sump screw compressor. For Haskels, be more concerned about removing all moisture from the air. The refrigerative drier equipped air compressors, or an external refrigerative drier, are a must have for Haskel air drive reliability in most climates.
I’ve used Chicago Pnuematic QRS series and they work fine. Id suggest the largest QRS they’e 15hp and can run 3 pumps.
These are cheap and good
