Talk:Vacuum pump/Archives/2014

Techniques

I removed the term "o-ring" from this article since it was inaccurately used. An o-ring is a seal which has an "o" shaped cross-section, or, in other words, is toroidal (see the wikipedia article "o-ring" for more details). The metal gaskets used in UHV are most commonly of rectangular cross-section. (Quantum.wells (talk) 15:27, 28 January 2010 (UTC))

Scroll pumps

Maybe someone can tackle how a scroll pump works...

I think we'd need an animated GIF for that one! It's pretty hard to visualize those sliding points of contact working their way closer and closer to the exhaust with every oscillation of the moving spiral.

Atlant 21:59, 20 Jun 2005 (UTC)

Done, Cacycle 22:37, 14 May 2006 (UTC)

Throughput definition

The current definition of throughput includes the sentence At a constant temperature, throughput is proportional to the number of molecules being pumped per unit time, and therefore to the mass flow rate of the pump. (Think PV=nRT). I think the phrase "at a constant temperature" may be misleading/incomplete because the temperature at the inlet of a pump will not be constant, and is generally not measured. Most pumps preferentially remove slow, heavy molecules, leaving behind light fast molecules at a higher temperature. But even without constant temperature, throughput is still proportional to the number of molecules being pumped per unit time, and therefore to the mass flow rate of the pump.--Yannick 15:32, 2 April 2006 (UTC)

Separate page for Toepler pump?

It's a good first-principles example of a positive-displacement pump, but it's not really a vacuum pump in the common-language sense ("pump out the stuff in a container"). Maybe it should have its own page? DMacks 05:56, 10 May 2006 (UTC)

Material Handling

A very common use of vacuum pumps in manufacturing is to move material from one place to another within a factory. For example, Conair Frainklin and AEC Whitlock sell vacuum loader systems for this specific purpose.

Please feel free to be bold and add information about this! Certainly in semiconductor fabrication, vacuum-pickers (both manual and automated) are used practically everywhere. Vacuum pumps were also used in computer card readers and high-performance magnetic tape drives.

Atlant 16:07, 9 June 2006 (UTC)

Even in some fancy ice cream vending machines:) DMacks 17:41, 9 June 2006 (UTC)

Yeah, I remember these. We had them at train stations in the Sydney CityRail network. The robotic (track) arm moved over to a packaged ice-cream, and a vacuum nozzle about 1 inch wide sucked and held onto the ice-cream's pack, then dropped it gently over the exit bay, as the vacuum was turned off, and slowly lost it's holding ability. Dunno why they got rid of those machines! DaveDodgy (talk) 13:22, 13 January 2010 (UTC)

Using vacuum pumps to suck water versus to evacuate a chamber

This article includes an introduction saying that vacuum pumps are used to remove gas molecules from a chamber, an application I am familiar with. I am not familiar with this being the same thing as pumping water from a water well and don't understand why vacuum technology, a large science, has examples outside of its field, and include all images but a basic eucentrically mounted rotary pump. This does not mean I require an explanation of how pumping water works or what pumping is. This is a general encyclopedia and should keep readers in the discussion of the topic, not move them to other areas. Water wells and chambers to be evacuated of gas molecules are not the same thing. It seems that people on Wikipedia disagree strongly and personally (on personal talk pages) with changes to articles. I will leave the vacuum pump article alone to those whom it belongs to. I'm sorry for editing it.

The preceding unsigned comment was made by User:Amaltheus.

There's really no need to apologize, Amaltheus. (For those who are interested in the discussion where I disagreed "strongly and personally", please see here.) Please note that although I reinstated some of the material you deleted, I preserved many of your edits which I found useful.

Water pumps like the one shown here are indeed vacuum pumps that must evacuate gas in order to draw water, and they're a good widely-known example to use to introduce the concepts of positive displacement and vacuum suction. When the pump is left idle overnight, air seeps into the well and the water level falls back to the water table, often several metres lower. In the morning the pump has to be primed by stroking the handle really quickly several times before water starts coming out. What's happening here is that the air is being evacuated from the well, and pressure from the atmosphere and dirt then pushes the water upwards to the pump. But even after the pump is primed and drawing water, it's still acting as a vacuum pump and relying on outside pressure to move the water. It doesn't matter whether you're pumping air or water, a vacuum must be free of both. (And water will boil off quickly in a vacuum anyway.) What separates a vacuum pump from other pumps is really just that it is being used to reduce the pressure at the intake instead of increasing the pressure at the outlet. And yes, there are pumps that do both and are in a huge grey area.

For sure we need a picture of a basic eucentrically mounted rotary pump as Amaltheus says, since that's the most common type of vacuum pump. However, Roots pumps and scroll pumps are also commonly designed and used as vacuum pumps, (e.g. [1]) and deleting these does not help the article.

--Yannick (talk) 04:59, 24 December 2007 (UTC)

Inventor

"The vacuum pump was invented in 1650 by Thomas Savery."

But when I click on Thomas Ssavery, I read he was born in 1650. Something must be wrong. —Preceding unsigned comment added by 155.55.58.31 (talk) 05:22, 17 March 2008 (UTC)

What, no mention of Penis pumps?

Technically they're considered vacuum pumps. -- OlEnglish ^(Talk) 01:42, 1 May 2009 (UTC)

DIY pump construction

DIY vacuum pomps can be made as follows: http://www.elektor.nl/artikelen-als-pdf/2009/mei/diy-vacuumpomp.926578.lynkx (english version coming soon) —Preceding unsigned comment added by 81.245.91.128 (talk) 15:02, 31 May 2009 (UTC)

using a compressor as a vacuum pump

I have an old (40's-60's??) air compressor, that seems to work well as a vacuum pump (if I use the air inlet). How well would/could this work ? It uses 2 pistons, I think, and is amazingly quiet. If this is of interest, could it be included in the article?DaveDodgy (talk) 13:45, 13 January 2010 (UTC)

Venturi/aspirator pump

Isn't the venturi/aspirator pump a momentum pump? The pumped fluid/gas is carried away by the stream, correct?

Fewwiggle (talk) 12:34, 14 July 2012 (UTC)

That's certainly where the pumped fluid/gas goes, but I don't think (but I'm not an expert here) that the actual origin of the pumping action is the same as in the definition of momentum-pump. In particular, there is an active pressure reduction at the inlet to the venturi tube rather than simply removal of molecules that happen to diffuse into the fluid flow. It's a viscous-flow phenomenon rather than a molecule-by-molecule momemtum transfer. DMacks (talk) 06:36, 16 July 2012 (UTC)