Vacuum pump and creation of vacuum

[McQueen]

I have got confirmation of sorts in the form of a pump that works at 1000 m³ h. (Which works out to 16.6 m³minute). with a power consumption of 1.5 Kw and pumps down to 10 ^-4 mbar which is much above 1 Torr (1.3mbar). To clarify, although the motor rating is about 5 Kw the power consumption is 1.5 Kw. Considering that the hypothetical problem set here was for a 7 cubic metre tank (i.e., about 2.5 times less than 16.6 cubic metre), and a final pressure of 1 Torr against 10^-4 mbar. Which is about 10 ^-6 Torr. I think the original figure I had given of a power consumption of about 250 W is well within limits. Still nothing like taking practical measurements as you had stated. Thanks for the input.

 

[sophiecentaur]

And how much energy is required to evacuate your hypothetical 7m³ tank? (the PV value). What running time for your motor would this represent and at what power??

There still seems to be (units) confusion as to whether you are talking about Energy or Power. A given power of motor can supply as much energy as you want, by running it for the appropriate time. Are you, perhaps, referring to the Power needed to maintain this 1Torr, once it's been reached?

Have you actually measured the power consumption of the 5kW rated motor? What method did you use? A real Power or Watt-Hour Meter - or just V and I? Where do you get your "250W" from? I should have expected the power from the motor to start high and then to reduce to a steady value - is that what happened?
When people describe the observations they have made on these forums, you can never be sure whether they have the whole of the CERN facilities or a Multimeter from Maplin haha.

You can see why Peer - Reviewed papers are required before the establishment will accept evidence to support any theory. We could be talking at completely cross purposes (all too common, I find - and it's not always my fault ).