silencing auto drains?

[kdupreez]

I am having a damn near heart attack every time an auto drain valve opens and 4000psi shoots with a excruciatingly loud pop and fizzzzzzzz.

I've tried a few things, - Even blew up a simple green bottle that had holes drilled into it and filled with rags.. My wife even came downstairs to make sure I still had all my limbs attached


any ideas on economical silencing techniques?

currently have a towel tightly wrapped and duck taped which works, but very ugly and its starting to smell..

 

[Wookie]

Try an auto drain silencer, like this one.

 

[kdupreez]

that works.. but $320 for 2 of these is not as economical as a tightly wrapped old towel

but yeah - thats for sure an option

 

[Scuba Duck]

Have something similar at McMaster-Carr for much less.

McMaster-Carr

page 348 in the catalog... called "oil mist recycling exhaust mufflers" or reclassifiers

 

[kdupreez]

awesome! Will these things handle 4000psi from my filter housing when the auto drain kicks in?

 

[Compressor Coach]

Kooz ~ the trick is to dampen the pressure blast (4000psi) before the air goes to the "exhaust muffler". Naturally, we offer a complete silencer kit which includes everything you'd need...but i think its around $500. You can probably figure out something of your own...maybe an old scuba tank as the blast dampner? Has to be something that is rated for the pressure.

 

[kdupreez]

Will a flow constrictor work with a big enough orifice? it should keep back pressure on the auto drain while it slowly drains out through exhaust muffler - my auto drains stay open for about 3-4 seconds?

 

[Compressor Coach]

It would probably restrict the air blast...but then, it would probably restrict the effluent discharge as well. If it did work you would certainly have to extend the drain cycle time.

Beware that if all of the effluent doesnt get exhausted, it will eventually build up and back up into the crankcase...or worse, cause hydraulicing/fracturing of the compressor cylinders.

A word of caution: Keep in mind that you are venting a VERY hi-pressure air stream and whatever you vent it into has to be able to withstand the pressure and volume of the blast. Otherwise you'll have a potential explosion on your hands. Please excercise caution.

 

[Scuba Duck]

On the older Bauer air compressors, the reclassifier is connected to the auto drains via some braided PVC tubing and hose clamps. No way that stuff would stand up to any sort of pressure. Make sure the filter element in the reclassifier is clean, remember, it is vented to ambient...

 

[Scuba Duck]

I made a drain bucket for a Dive shop a while back that worked liked a charm. The operating principle is that liquid water will not make tight turns and essentially gets thrown out of the stream of air. I got ahold of a 15 gallon polyethelene bucket (appropriate for the 17 cfm air compressor that it was attached to) that had two threadded holes where the caps screw on. One cap I used for where the air/water went into the bucket, the other I used for the muffler. I incorporated a hose barb, a union to make it easy to disconnect the thing, and some elbows and a muffler/silencer. Held several gallons of drain water (appropriate for humid Hawaii). When you want to empty the thing, just disconnect the union and pour the water out the union. Most drain collection systems make a mess and blow oily/snot water everywhere, this one collected all of the mosture. You could tell when the system blew down becuase the compressor became very quiet all of a sudden... Whole thing cost me about $50 for the parts.

See haistly slapped together drawing to get the idea...