Vacuum Distillation Setup on a Budget

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Discussion Overview

The discussion revolves around setting up a vacuum distillation system on a budget, specifically focusing on achieving a vacuum of 10 Torr. Participants explore various vacuum sources, including air compressors and aspirators, while considering cost-effective solutions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests using an air compressor and aspirator but expresses uncertainty about its adequacy for achieving 10 Torr.
  • Another participant doubts the effectiveness of the air compressor, stating it may not reach below ~2 psia even if modified, and recommends looking for a used vacuum pump instead.
  • A participant clarifies that they intend to connect the air compressor to a compressed air-powered aspirator rather than modifying the compressor itself.
  • There is a suggestion that the specifications of the aspirator should indicate the horsepower needed to achieve 10 Torr.
  • One participant mentions that a single-stage rotary vane pump can achieve 10 Torr and shares their personal experience with such a pump.
  • Another participant provides a link to a specific rotary vane vacuum pump that may be suitable for the setup.
  • Concerns are raised about ensuring that the glassware can withstand the vacuum pressure achieved by the pump.
  • Several participants share links to affordable vacuum-related tools available at Harbor Freight.

Areas of Agreement / Disagreement

Participants express differing opinions on the feasibility of using an air compressor for vacuum distillation, with some advocating for its use while others recommend a dedicated vacuum pump. The discussion remains unresolved regarding the best approach to achieve the desired vacuum level.

Contextual Notes

Participants reference various products and specifications, but there is no consensus on the optimal vacuum source or the necessary modifications to achieve the desired vacuum level.

GiTS
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Hi GiTS. I really don't think that will work. Even if modified to reduce piston ring leakage, it's only a single stage, so I doubt it would get below ~2 psia assuming it was properly modified. But modifying that is going to be more expensive than just getting a real vacuum pump.

Try ebay or Craigslist. A used one can be picked up for about $50 from what I've seen.
 
I don't want to turn the compressor into a vac. I want to hook the output up to a compressed air powered aspirator. But I don't know how much horsepower I need to get the aspirator to pull 10 Torr.
 
I should think the specs of the aspirator would tell you.
 
Incidentally, 10 Torr is well within the capabilities of a single-stage rotary vane pump, of the type used by HVAC repairmen. I have one I use for various nefarious vacuum-related experiments.
 
thanks for the tip. I think this might be perfect
http://cgi.ebay.com/Rotary-Vane-Vacuum-Pump-29%22Hg-3-CFM-1%2f4-HP-AC-HVAC-Tool_W0QQitemZ390068911886QQcmdZViewItem
 
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29 in-Hg of vacuum works out to 736 Torr below atmospheric (which is nominally 760, depending on where you live / work).

May want to make sure your glassware can handle that without imploding (assuming that you in fact reach the ultimate pressure of the pump).
 
  • #10
You need one more like this one:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390066833029
 
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