I just set up my system to use two injection coils, and have a couple of questions. I have 100# tank with a 70 tane/30 pane blend. I run 4.5 lbs of material in a 6x36 column. My injection coils are submerged in dry ice/acetone and I plan on having my Solvent sit in the coils for an hour so it gets chilled down to -70. Once chilled to -70 I’m going to open the valves on the coil, and material column and fill that up with 20lbs of splvent and let it soak for 1 to 2 minutes…then dump into my collection pot and recover…
First question… It is my understanding that when you run solvent this cold that no fats is pulled from the material and dewaxing is not required.
Second question…Do any of you see any issues with solvent flow using a double pre injection coil?
I use two coils like this and see no trouble at all. If you aren’t using nitrogen, then your solvent is staying in the coils. Because of the temp of the column your shoving it into. Butane wants to stay in the coldest environment. Push with nitrogen and you won’t see any issues at all…
And yes if you extract that cold you shouldn’t pull fats, if so, it’ll be minimal
Yup! Solvent flow was a trickle and took like 30 mins to fill the column when it normally takes just a couple of minutes at most. I do have nitrogen on hand but I’m not confident in using nitrogen to assist yet. How do you gauge how much to burp put of your recovery tank and if it is nitrogen coming out.
I’ll do some more research and reading the forums on it, but I’m going to switch back to one coil for now.
That first run came out a little darker than normal and I think that had to do with the material being soak for so long while i was waiting for the column to fill. Other than that it definitely shattered up nicely. Thanks for the reply guys.
Yes that would be unavoidable if you have propane in the mix because its so volatile. Some will always leave with the nitrogen when you depressurize for recovery.
According to Daltons Law, the total pressure of a mixture of ideal gases is equal to the sum of the partial pressures of the constituent gases. The partial pressure is defined as the pressure each gas would exert if it alone occupied the volume of the mixture at the mixture’s temperature.
Although the temperature and pressure ensure that the propane is a liquid some will still escape when you depressurize. Not a lot at a time but more propane will leave than butane/isobutane.
It will eventually throw off the ratio, how quickly or slowly it will do that depends on how cold your getting.
So for an example, let’s say I have 10gal of a 70/30 mix of two gases. The 70%, 7g, at room temp is 10psi. The 30%, 3g, is at 5psi. So the total psi would be 15?
When in doubt assume you can vent as much as you add when your temps are low enough to keep the lightest hydrocarbon in your mixture (or alone) as a liquid.
Yes you do need additional pressure to help push the solvent through. Otherwise it will move very slow through the coils.
I have my system configured differently since I posted this thread. I can now send and build pressure into my solvent tank which will help push the solvent through. I may try this again soon and see I’d I get better results.
Well I’m running a 50/50 butane propane mix. Do I really need to boost the pressure anymore? Maybe put my solvent tank in warm water to boost vapor pressure?
I know you guys are saying run nitrogen but what I came up with instead was running a hose from a the recovery gauge manifold to a T in the injection hose so I can use the vapor pressure from the pump instead of running n2
