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Hey nicodemusliam, welcome aboard RIU!
Check back in a couple of days, I've made a working demonstration CO2 Subcritical fluid extractor model from stuff I had around the house and a couple of cheap things I had to pick up. The product can't be used because the extractor parts aren't all high purity stainless steel for corrosive fluids and gasses, but its the
daddy-O of all demonstration models for our group. A few people will have most of the parts already but I had to modify a couple of them to make the scfe work, and its almost as cheap to buy high purity fittings second hand to make a usable honey oil.
The subcritical extraction process (basically the same as a butane extraction) is incredibly simple:
Constant temperature and pressure within a localized field.
We do this by adding heat to overcome Boyles Law, (The Ideal Gas Law) - as a gas expands there is less heat in the same volume of space (the tank) so the temperature goes down. Some of the heat leaves with the CO2 we are going release for extracting, the remaining CO2 must be warmed to 88F+ so it can be used for extraction.
As well, the CO2 being used for extraction is reduced from as high as 3000 psi to ~600 psi - it is going to be cooled when it leaves the tank and must be warmed to at least 88 F before it goes into the extraction tube. I do this the easy way, you can do it an easier way.
We need the fast transfer of heat to the cold CO2 and maximum surface area will speed heat transfer. Water is much denser than air so it can transfer heat quicker. A small water pump in your heating chamber will keep the water moving to speed heat transfer - cooled water moved away from the heating coil and warm water moved against it. A stainless steel coiled hose has a small diameter and a great surface area for the same volume as a tank, better than a second tank for expansion though the second tank can be used as well as the coil.
We heat the CO2 tank in water above 88F and release the 3000 psi CO2 into the SS coil at 600 psi and use a small volume/minute of CO2 for extraction, to give the remainder in the tank and coil time to warm back to 88F. When we release the CO2 from the extraction chamber (~600 psi) to 1 atmosphere (15 psi) there will be a reduction in temperature as well, another coil can be used to move the pressure reduction point out of the extraction tubes heating water and into a second tank of water, and then the CO2 and resin are vented to a resin harvester.
You guys are going to love my resin harvester, and the whole extractor. Very Trailer Park.
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Most of you folks will use two of the regulators below to heat your CO2, forget everything above. The regulators have inline heaters, or we can buy or make seperate inline heaters for second hand high purity regulators Part of the fun for me was to design an extractor that could be used anywhere without electricity (as an economic development tool), but if you've got electricity lets be practical. This stuff goes in number 5 on the sheet, I took it out to see if any paintballers or scuba people were reading the thread.
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