LSD25 - 28-1-2008 at 02:27
I decided today, as I was at something of a loose end (still a lot of projects to finish, but all need some part or component or chemical which is
either unavailable, in transit, beyond my means or whatever), to make a decent manual syringe-type vacuum pump from simple materials.
Although these pumps are of limited usefulness of themselves, when they are used to evacuate a small-medium vacuum resevoir, they allow for small to
medium vacuum distillation. Of course by themselves, they are extremely useful for vacuum filtration.
Anyhow, see what you think (comments welcome)![:D](./images/smilies/biggrin.gif)
PS At the top of the stroke (max compression - atmospheric pressure) the height of the headspace is around 1cm. The stroke is around 20-25cm so the
expansion is around 20 times the headspace. This thereotically means that the pump is capable of pulling a vacuum of around 1/20 atm.
http://tinyurl.com/28fe39
microcosmicus - 28-1-2008 at 10:07
Nice little hack --- a piston vacuum pump built without a machine shop. Your price
of $50 and a day sounds like a conservative overestimate to me, or do the toilet
uncloggers retail for an exorbitant price? Likewise, the work involved sounds
more like a half-hour to me.
As for rocket surgery, I suppose you could instead fill the syringe with propellant
and launch it ![;)](./images/smilies/wink.gif)
chemrox - 28-1-2008 at 15:44
Nice pix. I've never seen anything like this in the hardware stores where I live. It's labled vacuum/suction. Did you write that on it? For under
$50 you can buy a hand-operated vacuum pump; often sold as a "brake bleeding kit." I use one to keep my vacuum dessicator evacuated.
Who is affraid of aspirators? I modified my plumbing to accomodate one and it pulls 25 torr. The backflow trap is essential- when anyone runs water
nearby the flow changes and water runs into the trap. Other than that, its a really nice steady 25 mm for filter flasks or distillations that can run
with that high a pressure. I don't see how you could use your device for anything but filtration or as I do for the dessicator.