Despite this name, it seems to be a vacuum pump. Has anyone seen these
installed anywhere?
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Ignoramus31221 wrote:
Despite this name, it seems to be a vacuum pump. Has anyone seen these
installed anywhere?
Vacuum pumps are a particular form of compressor, with an
extremely high compression ratio. They take gas at VERY low
pressure and raise it to atmospheric pressure.

I saw something about it a couple years ago, and have forgotten
most of the details. But, the basic scheme is just like a Gast
carbon-vane pump except that the seal is maintained by a liquid
that is slung outward by centrifugal force, allowing the pump to
handle dirt to some degree. How they clean the fluid to prevent
it from totally jamming up is not clear.

But, Google shows :
http://www.travaini.com/liquid-ring-compressors.htm

Jon

Ignoramus31221 wrote:
Despite this name, it seems to be a vacuum pump. Has anyone seen these
installed anywhere?

We used liquid ring pumps to withdraw and compress
digester gas (wet dirty methane). The pumps will
draw a vacuum on the intake side and discharge to
a pressure higher than atmosphere on the outlet.
They work with dirty corrosive gases and don't
complain.

Here's a pretty good description...

http://www.fluidcompressor.com/products/

On Fri, 18 Jul 2008 10:18:07 -0500, Ignoramus31221
wrote:

Despite this name, it seems to be a vacuum pump. Has anyone seen these
installed anywhere?


They are used (amongst other things) as condenser air extraction pumps in
power stations.

They don't wear out. The working fluid can be water and is replenished
automatically as a side effect of pumping half psi steam in with the air.

The condenser air extraction pipes are in the centre of the condenser
tube-nests, where the incondensibles migrate to. The pumps pick up a mixture
of air and steam. The excess water from the pumps is simply returned to
feedwater and the damp air is vented.

Steam air ejectors are used initially to pull the vacuum before starting the
turbine, but the rotary pumps are used to maintain the vacuum.



Mark Rand
RTFM

Ignoramus31221 wrote:
Despite this name, it seems to be a vacuum pump. Has anyone seen these
installed anywhere?
why would you want one

On Fri, 18 Jul 2008 10:18:07 -0500, Ignoramus31221
wrote:

Despite this name, it seems to be a vacuum pump. Has anyone seen these
installed anywhere?

I rebuild about 2 or 3 a year which have run 24/7 for 6-10 years
pulling vacuum on gas wells.

Ignoramus31221 wrote:
Despite this name, it seems to be a vacuum pump. Has anyone seen these
installed anywhere?

I had one. I sold it on eBay a while back though. Here's a pictu
http://www.mythic-beasts.com/~cdt22/vac_pump.jpg

I don't know much about them. But I think that from a home workshop or
science projects point of view, a rotary vane pump is more useful.

Best wishes,

Chris