Talk:Vacuum pump

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Contents 1 Scroll pumps 2 Throughput definition 3 Separate page for Toepler pump? 4 Material Handling 5 Using vacuum pumps to suck water versus to evacuate a chamber 6 Inventor

[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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)