Tacho
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A small simple continuous extraction apparatus.
I've built this one to check how much oil there was in a certain seed. I used ethanol as solvent, I don't think it will work with more
volatile solvents.
You have to keep an eye on it to make sure everything is ok, but it as simple as it gets:
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Oxydro
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Registered: 24-5-2004
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Possible improvement
I've been thinking about something along those lines for a while, although I hadn't exactly got as far as deciding what parts to fit
together how. What strikes me about your design is the lack of anything to prevent evaporation between the end of the condenser, and the container you
use to hold the raw material.
I would suggest maybe adding some kind of cover between the two, so that solvent losses are reduced, and to open up the possibility of more volitile
solvents where losses would be unacceptable. If you could find a rubber stopper for the the top of the funnel (call it what you will), you could just
lead a little piece of plastic tubing over the pipe and in through the stopper. A cork might even work.
Neat looking setup you have there. It looks like just the thing to inspire me to get my own system built and working. Could you post some details
about how you made the heater assembly, and any other useful details?
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Tacho
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Thanks Oxydro,
I also think this design is neat, and I was a bit sad that this thread was becoming an all-time-looser with fifty-something views and no replies for
almost a week.
About the evaporation of the solvent: To my specific needs, it doesn't matter, since I just add ethanol, that is cheap and widely available here,
as needed. Besides, Since I want to isolate the oil for measurement, I'll eventually have to get rid of it anyway. But is does pose a certain
fire-hazard and, as I said, more volatile solvents may require, at least, ice-cold water in the short condenser. The cork idea may work, but some
pressure release will be needed. Also, as I said, this device should not be left alone, I keep an eye on it while I do other things in the attic.
The construction uses 1/4" and 5/8" copper tubes used in refrigeration/air contitioning or gas trades. There is no logic in the diameters;
they were at hand in my scrap and I had a stopper with holes that fitted a 5/8" tube. No other tube material is as easy to bend to shape, and
its more than hard enough to hold everything stiff by itself, with no clamps or wires.
I believe any funel with filter, even paper filter, will work.
The condenser is made of a short 3/4" diameter (25mm) PVC pipe with two caps (drill the holes for the tube before you glue them) and two short
1/4" copper tubes inserted for water flow. The main copper tube passes right through it and all tubes are glued with 10 minutes araldite epoxy to
make the thing watertight (sp?).
The solvent tube is a 50ml graduated pyrex centrifugue tube. I use graduated because I can measure the oil left without changing tubes. Dont miss this.
The heater I used was build very carefully using NiCr wire, phosphate cement and silicone rubber molds, plus some paraffin molds that were melted
away. It's construction is quite complicated and dedicated to those 50ml tubes (only them). Involves many steps, but if you are very interested,
I could give you the details...
I think there are many other options for heating.
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Organikum
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great setup !
Lke it very much.
Cannot understand why I overlooked it before.... 
I would like to make one suggestion for improving the apparatus:
PVC is a lousy material for solvents and you already have a coppertube going up, so I would suggest to use the end of the tube as condensor and to fix
just a PVC waterjacket around the coppertube.
This would provide an apparatus suitable for all common solvents without much more effort.
Depending on the solvent some insulation on the coppertube going up might be useful too.
A great inspiration nevertheless for I am going to build a somehow larger continous extractor ("perforator" for liquid/liquid extractiof yeast mediated reactions. But this will have to cope with
5-20 liter buckets and ether as solvent. (Biosynths are volumetric not so advantageous...)
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Tacho
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| Quote: | Originally posted by Organikum
I would suggest to use the end of the tube as condensor and to fix just a PVC waterjacket around the coppertube.
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Hmmm... but that's exactly how it's built!...
| Quote: |
A great inspiration nevertheless (snip) |
I'm happy to pay back some of the good stuff you post!
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Organikum
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Urghhh !!!
Read "PVC" condensor and got the wrong idea.
In this case: Marvelous!
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