Douchermann - 25-4-2008 at 19:41
After running a single stage vacuum pump at roughly half vacuum (controlled by a home brew regulator) the action side of the pump is quite hot to the
touch. The motor cooling fins however are just barely warm. I'm just curious how hot they're supposed to get, and if/when I should be concerned,
because at the moment, it's the most expensive single lab component I own.
franklyn - 25-4-2008 at 20:21
Odd, a vane pump set to compression one expects would run hot, not one
set to evacuate air, although once you have vacuum there is no air to cool
it internally so the heat generated by seal friction will be felt externally.
Check the manual specifications specifically for maintenace and lubrication.
Also use a valve to close off your vacuum once you have it, don't run the
thing constantly that may be beyond its duty cycle. Also be certain the
pump material is not corroded by whatever vapor is being vacuumed.
.
garage chemist - 25-4-2008 at 20:31
My organic chemistry book says that rotary vane pumps are supposed to get hot (80°C), it even is good for them as it keeps vapors and moisture from
condensing into the oil, prolonging its useful life.
VTchem - 25-4-2008 at 20:35
We have 2 rotary vane pumps at home and they get warm, I wouldn't say HOT but then again I don't really touch them that often while they are running
so take that with a grain of salt. I would say as long as you aren't burning any oil you should be in the safe zone, but looking into the specs of
your particular machine is the safest way to go.
chemrox - 25-4-2008 at 22:51
Mine get to around 80*. They don't pull max vac until warm. Too hot to touch would, to me, indicate too much friction. Bad springs or rotors ..
whatever keeps the vanes against the cylinder walls. Maybe wrong oil or decomposed-contaminated oil. Try a flushing oil for 15 minutes to an hour
and then drain and fill with good oil. Always use high quality vacuum pump oil and nothing else.
Rotary Vane
MadHatter - 25-4-2008 at 23:46
Interesting, my oiless system doesn't get hot unless I run it for several hours. Sounds like a friction problem to me.
Douchermann - 26-4-2008 at 10:26
The oil isn't smoking, and it is high quality vacuum oil. It pulls great vacuum (boils water at 13C, possibly lower). I recently flushed it, and
this oil is nice and clean. The manual it came with was something closer resembling a napkin with some scribbles on it. There was no important
information on there except the drain/flush process which is or should be, common sense. For those curious, it was the single stage rotary vane from
www.cynmar.com (the cheap one). Thanks for your help, It seems lower than 80C so we should be good.
[Edited on 26-4-2008 by Douchermann]