Oxirane
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Centrifuge
I had a boring day so I went to my lab and mixed up some CaCl2 with NaOH, which quickly dissolved and soon Ca(OH)2 was precipitated as a white milky
slurry, into which 2 times more water was added, stirred for a while, and then let to stand, clear supernatant removed with suction tube, and washed
twice again. This was quite an easy job since calcium hydroxide formed flakes which took only some minutes to settle, especially on hot water, but
I've faced few other cases where only a colloid was formed, impossible to separate by any means of distillation without using multi-step complex
washing, acidifying, basifying etc. steps. I wished I had a centrifuge. Then I began researching the subject and found out that the device in
principle is not so difficult at all to construct! Basically, all you need is an open type separator bowl, and a motor to run that thing!
https://www.youtube.com/watch?v=PsLGX-RbKuQ
I am planning on making one sometime. I'd use solid chunk of 160mm steel rod which I would turn into a separator bowl in a lathe, and then make the
structure, bearings and motor around it. Normal 3000RPM 50hz motor from a drill press would give it about 800-1000G, but I dont know how powerful
motor will I need? Is 250W enough, or should I install a larger one of 800W? I dont know also how much G forces are needed for different material
separation, and can G forces actually be used to crash out some dissolved fractions? Some power drills could be perhaps used for this purpose too
since they have deduction gears which can give huge RPM's, way over 3k RPM and the separator is not usually run so long the motors would give up due
to lack of proper cooling.
The bowl material, if it is carbon steel would restrict its use for somewhat, so mostly no acids could be used. Aluminium which is mostly used on oil
separators due to its much lower weight and easier machinability is even worse since it is readily attacked by any acid or basic chemical. Stainless
steel would be more ideal, but such a chunk of acid-resistant grade will cost way too much for my current project budget. Chunk of steel can go as few
as under 20.
160mm bowl at 50mm height would be large enough to be used for separating up to half a kg of solids at one run before cleaning, and best of all, these
solids could be washed in run with large amounts of solvents in very small volume while the device is running. Probably even some fertilizers could be
literally dissolved dry of anything valuable using quite small amounts of boiling water.
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Varmint
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A centrifuge should be balanced to a very high degree, so the only losses to be dealth with are rolling friction of the bearings, and windage of the
rotating mass.
Ergo, the power requirements should be quite low, a sub-fractional HP motor should do the trick.
DAS
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Oxirane
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All commercial installations use fairly strong motors, even for under 200mm bowls they can have over 1kW of power.
The balancing should be easy task when the bowl is turned in a lathe.
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Varmint
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Ah, I see. You want a uranium separation grade centrifuge to get your everyday chemistry to layer out.
LOL.
DAS
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Oxirane
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Well, I was thinking something that can bring apart lime water and colloids easily.
I found and old juicing machine that essentially has a perforated bowl which acts as a centrifugal filter. I blocked the holes with aluminium tape and
got substantial separation from lime water, but the smallest particles remained in the suspension. Problem was the apparatus still leaked quite a bit
and the centrifuge worked only because the liquid had to travel a small distance to the holes.
I think this is my most stupid project for a very long time. I don't really need a centrifuge nor can I name any use for it - but I just want one.
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Texium
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Thread Moved
21-11-2023 at 14:18 |
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