I want to assemble a "hobbyist-level" vacuum distillation apparatus for extracting small volumes of "typical" solvents (e.g., water, alcohols, ketones, diols).
I already have standard lab glassware with 24/40 joints, 10mm barbed inlets.
How do I select a suitable pump?
- I would want a pump that can run for extended periods to perform vacuum desiccation.
- So far my research suggests that I should be looking at diaphragm pumps, but:
- I don't know if there are other features or specifications available in a low-three-figure pump that will make life easier.
- What kind of tubing do I want? I know that larger inner diameter is better, but I don't know if something special is used instead of regular tubing to support the vacuum, or what the standard adapters and sizes are to come off the 10mm glass fittings.
What elements need to be part of such an apparatus, and how should they be configured? E.g., I have seen mention of:
- Filters: What are used, and when are they necessary?
- Traps: Does this only refer to "cold traps," which I understand to simply be another condenser in front of the pump? If so, is it correct that this would only help if I can cool the "trap" significantly below the temperature I'm using for the primary distillate condenser?
- Capillary bubblers: I can't even find anything on these, other than what's mentioned here.
Also, how do these answers change if I'm doing vacuum desiccation of the named solvents (i.e., where the only difference is I don't care to capture the evaporate)? E.g., can I just let the system exhaust through the pump?