Vacuum pressure

[Carrington]

Hi all just picked up a big vac pump I got from eBay. It's a bit of a beast and needs a good clean and probable service. The plate say's it vacuum is 15 torr does any one know the calc to convert that into bar or " mercury

Cheers

Paul

[Glycer-rides]

try this:
http://www.unit-conversion.info/pressure.html

It looks rather small, 0.02 bar!

[Tony]

Try googling "15 torr in mm mercury" or "15 torr in inches mercury" (answers are 15 and 0.59061888 respectively).

Google does many conversions for you automatically, which is very very useful for daft things like "30 cubic feet in litres".  Quick and easy conversion - love it!

[Carrington]

Cheers guy's
That does seem very low
Well give the manufacture a call tomorrow with all the id numbers see what they say. It could work out to be a cheep air receiver for compressor

[greasemonkey]

That graph hasn't copyed very well, I'd have been better posting a link.
Basically, from what I can gather, atmospheric pressure is 760 torr, so 15 torr is very near reducing atmospheric pressure by 1 bar, which has been said already anyway.
The only thing I can relate it to is to think about a how hard a tyre goes with 1 bar in it, and sort of reverse it in my head. It seems quite a powerful machine to me.

http://en.wikipedia.org/wiki/Torr

Scrubbed the graph. heres the link.

[Carrington]

Just found a on line calculator to do the math for me.
At 15 torr water will boil at 18c and meth will boil at -4, should be worth having a play with.

[Rotary-Motion]

Just found a on line calculator to do the math for me.
At 15 torr water will boil at 18c and meth will boil at -4, should be worth having a play with.

hmm thtas interesting....

[Carrington]

Just copied over the calc page if anyone wants a play

http://www.trimen.pl/witek/calculators/wrzenie.html

[Rotary-Motion]

so looking at this if you vacuumed the system you could lower the temp for convertion and save alot on the leccy biill, but could it ever be possible? re a closed system / rig i guess is not advised...

[Carrington]

I get my process heat from a oil fired boiler so reaction temp not really a problem, but it does mean I can boil my bio at a much lower temp than its burn point. I'm also hoping that I can de-meth quicker as well

Paul

[Dickjotec]

It occurred to me that a gas bottle could be used as a separate demeth vessel, it would easily cope with the vacuum I would think and if the process under vacuum is fast it would then not be necessary to go above 65 degrees with the oil, just process then demeth? The catch tank would also need the be under vacuum and I am not sure how the condensing would work, could it be by pressure increase? Remove the vacuum and the vapour returns to liquid, a bit like a fridge.
Dick

[kamaangir]

Paul how much was the pump? I fancy one of those for the wmo/plastic cracking unit I have in mind.

[Carrington]

Hi kamaangir
Ive been thinking about plastics also. Thought I'd start with some easy stuff first then work upto the more complicated stuff. I'm not interested in WMO as the permit to accept WMO would cost about 20k.
The pumps aren't cheep it's a big investment mine cost £77.00

[kamaangir]

I am not going to do it commercially, it would also just be a proof of concept type thing any way, was thinking about something like a propane/lpg cylinder suitably modified for use as a processor. With the vac pump you can lower your temp and not worry about oxygen infiltration.

You could use it to distill your bio too!

[Carrington]

Yes I have a 90L vac tank similar to gas bottle but it has windows in allowing me to see what's going on (I hope). I should finish my bricklaying day job next week so can start putting things together.