sponsan (Stranger)
05-13-02 13:31
No 307923
      please comment on the following vacuum pump  Bookmark   

Hello bees!

Dreaming of getting this particular rotary oil circultion vacuum pump.  Following are some of it's specs:

Pumping speed (m3/h): 3.0
Total Final pressure (Abs) (mbar): 2

...suitable for evacuation of small closed systems or for continuous suction within a pressure range from 200 to 2 mbar (ABS).

Would this pump be suitable for high vacuum distillations such as distillations of high boiling point oils and ketones?

Thanks heaps!

Thank you,
(Hive Bee)
05-13-02 16:38
No 307951
      pump  Bookmark   

2mbar is not a high wacum, An oilpum should go down to 0.05mbar.
(Hive Bee)
05-13-02 22:09
No 308067
      hey now!  Bookmark   

check out the ritchie yellowjacket hvac 1.5 or 3.0 pump.sick skills homey its just a bronco gotta tame her and less than 300.Send a PM for more details now!or UTFSE! tongue

I will choke untill I swallow!Who are you to judge or strike me down!Miss you Kerra!
05-14-02 05:25
No 308210
      2mbar enough  Bookmark   

edit :2 mbar is about 15 mmHg. As Osmium pointed out, 2mbar is in fact 1.5 mmHg. I dropped the decimal when typing, stupid boy that I am. Thanks Os.   This is a respectable vacuum, though not what would be considered "high vacuum" in any self-respecting lab.
2 mbar is more than adequate to distill the ketone. metwurst has an aspirator station that pulls a mere 25 mbar, and ketone distillation occurs at about 154C. The ketone does not polymerize, and almost no residue is left in the source flask after a single distillation.

There are better pumps to be had, though they are beyond the financial constraints some people are limited by.

(argh! I'm now guilty of misinformation.)
(Stoni's sexual toy)
05-14-02 10:35
No 308307
      > 2 mbar is about 15 mmHg. No! 2mbar = ...  Bookmark   

> 2 mbar is about 15 mmHg.

No! 2mbar = 1.5mmHg!

2mbar will be more than adequate to distill ketone. But when a pump is rated at 2mbar it will not achieve that kind of vacuum under normal operating conditions. But it should still work.

I'm not fat just horizontally disproportionate.
05-15-02 03:07
No 308594
      water aspirator station instead of hvac pump  Bookmark   

Hello again bees!

After carefully considering my options and lots of research and being a total novice oz bee, i've decided to drop the idea of buying a vacuum pump or messing around with fridge compressors.

Instead, i have aquired a second-hand Davey water pump, which has a 0.6hp motor and produces about 50PSI pressure at zero suction depth.

I will be building a recirculating aspirator stating simmilar to the one discussed on the web site using this pump.

I am also aquiring a brass water/air aspirator, which i am going to hook up to this pump.  The aspirator is fitted with a non-return valve.

For measuring the vacuum created, i am planning to use an automotive boost/vac gauge.  These gauges are relatively cheap over here, and the one i am looking at has a range of 30" Hg to 20 PSI, should be able to tell me approximately what vacuum my aspirator is generating.

Could someone please tell me if i am on the right track so far?

Thank you,