I have found a site that sells vacuum pumps and supplies in the Web. I have a question on one item. This one is a low priced dry trap, that consists essentially of a container with zeolite ( is is the same as molecular sieve, BTW ? ) in series with the vacuum pump.
I would like to know if this setup would be effective in avoiding solvents, water and the like from degrading the vacuum. Right now, I have to change my pump oil everytime I distill ketone or the like. Typically the vacuum starts at 0.80 mmHg, at the end of the distillation it is at least 2.0 mmHg, sometimes degrades to about 10 mmHg. After flushing the pump and changing the oil, back to 0.80 mmHg.
BTW, I am starting with the aspirator, then switching to the pump, but still see the vacuum degrading more than I would like it to.
If it is OK, how many times could I use the pump before having to reload the zeolite ?
Also, how much the vacuum would be lowered by the extra hardware in series with the pump ?