18.104.22.168 Subzero Extraction
For ya’ll brothers and sisters looking to process larger quantities at a time, we recommend that you consider the Subzero Ethanol process, by which either fresh cut or dry material is packed in bags, which are subsequently placed in a stainless vessel at ambient temperature, through which ethanol at >-50C or lower, is pumped in a circle through it, as it is being agitated, dissolving and removing the essential oils.
Temperatures that low are typically achieved by adding dry ice to the bath of ethanol.
A pump is required that can operate at those temperatures, and due to low seal elasticity at those temperatures, typically a mag drive pump without seals is required.
At those temperatures, full extraction of 25 to 30 pounds of material takes about 10 to 15 minutes, before being passed through a 0.5 micron PTFE coated polyester felt sock filter, available from places like Duda Diesel.
Subzero system using cryogenic mag drive pump
Here is a conceptual of a system that uses either nitrogen or air pressure to transfer the liquid from the storage tank through the shower head into the second tank of plant material, and then a gain to blow it from the process tank back to the storage tank. Pneumatic pressure can also be used to transport it to the next next process.
Subzero extractor using Nitrogen pressure to cycle