Ben Shelton on wed 28 jul 04
I am doing some experiments on clay bodies requiring lots of 5 r 10 pound
batches of clay slip to be dewatered to plastic clay. This takes way too
long in this cool, wet summer here in Kentucky. It is painful waiting 2~3
weeks for 10 pounds of slip to dry out. SO I am tinkering with the idea of
a vacuum filter press. The press should be easy enough to build but the
vacuum pump is somewhat of a stumbling block.
I wondered if I could use my old air compressor as a vacuum pump? I have
replaced it with a better one and now it just sits around. I bought a vcuum
guage and found out that the intake of the compressor pulls about 27.5
inches.
Of course I am a little concerned with burning this little machine up. That
would be a pointless waste!
SO, Does anyone have any knowledge about compressor/vacuum pump design that
would tell me whether I am heading towards total meltdown or could this be
done safely with proper safety valves and swithces?
Thanks to all
Ben
Vince Pitelka on thu 29 jul 04
> I wondered if I could use my old air compressor as a vacuum pump? I have
> replaced it with a better one and now it just sits around. I bought a
vcuum
> guage and found out that the intake of the compressor pulls about 27.5
> inches.
Ben -
This should work fine. In the past, I have used refrigeration compressors
converted to work as vacuum pumps. And as you may know, many of the
commercially available vacuum de-airing pugmills use piston vacuum pumps
that are virtually identical to compressors except that they do their work
on the intake side rather than the exhaust side of the pump. You are
apparently fortunate to have a compressor with a pipe connection on the
inlet side, which is not true of many low-end compressors.
There is little chance of you burning out your compressor. It should do
this job just as effectively as it compressed air. Monitor the barrel
temperature, and shut it off if it gets too hot, but I do not expect that
will happen.
One thing to check - I would call a vacuum pump supplier and find out if the
crankcase oil should be the same type and weight as is used in a compressor.
And since you will be working on a vacuum, small amounts of oil will be
sucked up above the piston, and will be expelled with the exhaust, so be
sure to check the level of the crankcase oil frequently.
Good luck -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
pdp1@EARTHLINK.NET on thu 29 jul 04
Too...if the cylinder seems to be a mite warm, one may drape
a folded wet rag on it and run a fan over that...and keep it
sopping 'wet' as well...
Phil
el ve
----- Original Message -----
From: "Vince Pitelka"
> Ben -
(snip)
> There is little chance of you burning out your compressor.
It should do
> this job just as effectively as it compressed air.
Monitor the barrel
> temperature, and shut it off if it gets too hot, but I do
not expect that
> will happen.
>
> One thing to check - I would call a vacuum pump supplier
and find out if the
> crankcase oil should be the same type and weight as is
used in a compressor.
> And since you will be working on a vacuum, small amounts
of oil will be
> sucked up above the piston, and will be expelled with the
exhaust, so be
> sure to check the level of the crankcase oil frequently.
> Good luck -
> - Vince
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