banana buds
Member
before getting started, I need to say a huge thanks to those who made this project possible. gray wolf, jump, foaf, doublekindness, and others have been very kind to share their experiences so that i may stand on the shoulders of giants. if you are planning on embarking on a project like this, you would be well served to read their respective threads several times each.
My system is built as follows:
-5 gallon pressure pot for the flask
- 4"D x 24"L extraction column - 304 SS tri-clamp spool section
-appion g5 twin recovery machine
-IP n-butane (99.5%) tank for the solvent
the column end caps are also 304 SS. I had my machinist tap holes into the end caps to allow me to put fittings and a gauge on my column. I currently have 1/4" brass flares (using 1/4" MPT x 1/4" FL pieces) for my hose connections, and a 3/8" ball valve for the dump line into the flask.
the column top cap has a pressure gauge ( 30"Hg to 100 PSI), two spare 1/4" flare fittings that are capped, and two 1/4" flares that are used for pre-vacuum and butane breather/overflow.
the column bottom cap has a 1/4" flare fitting for the butane fill line, and has the 3/8" NPT ball valve that dumps down into the pressure pot.
the pressure pot is completely unmodified at this point other than removing a section of handle to clear the column. it sits in a 27 gallon tote filled about halfway with water that is used to heat the system during recovery. I tried using a 300 watt aquarium heater but it was inadequate (although better than nothing). my current solution is a submersible pump that pushes the bath water through a 1/4" copper heat exchanger coil which is currently resting in a large crock pot cranked to full heat. this gives me a pretty constant 100*F bath around the flask, which I am mostly happy with at this point.
when using a scale for the tank (which is not 100% of the time), i have a tif 9010 that works great. lines are all standard hvac type lines that are rated for handling much more pressure than this system should ever see. in addition to the gauges on both the column and flask, i have a set of yellowjacket manifold gauges that control fill/recovery. altogether if you count the gauges on the appion, there are 6 different ones in the system! yowza!
my initial gasket sets were white platinum-cured silicone, but these have proven unsuitable as they expand after some period of use and will no longer even fit the flanges.
i'm using 2mil teflon PFA pail liners (5 gallon size) to avoid scraping the flask. my procedure here is to carefully slip the bag in and fold the top over the rim of the pressure pot. i then snake a vacuum line in under the bag and suck out as much of the air underneath as possible so that the bag is tightly sucked against the sides of the pressure pot. the bag does not appear to cause any issues with the lid/pot seal, and allows me to quickly and easily remove a batch from the system and reset with another bag.
inside the pressure pot i have a tube that has 200-hole stainless cloth over the end to catch any particles before they are dumped into the pot. this also directs dumps into the middle / bottom of the pot, since my column is actually dumping through a hole that is offset in the lid.
for particle filtration, i have 100-hole stainless cloth discs pushed into either end of the column (3-4 per end for safety) and then
my current running procedure is thus:
1) pack column with approx 500g of material and put filter discs into ends.
2) put teflon bag in pot, vacuum it to the pot, put lid on.
3) mount column, tighten tri-clamps and then double check all hoses and fittings for tightness and proper settings.
4) fire up the vacuum pump and pull a good hard vacuum on the whole system for about 30 minutes.
5) fill column (remember this is a bottom fil) until the top breather line feels cold - this ends up being around 5 or 5 1/2 lbs of butane.
6) shut breather and fill lines, turn on recovery machine and pull pressure pot down to 10" vacuum (this takes a few minutes)
7) open dump valve to dump butane into pot. once pressure is equal between pot and column, top breather line is opened to allow any last dribbles to make their way down.
8) turn on recovery machine, and run until it gets whole system down to 10" vacuum (with current bath temps this usually leaves 2-4 oz of butane still in the system).
9) repeat steps 5-8 another 3 times - for a total of 4 butane soakings
10) allow appion to pull all but the last 2oz of butane back into the system for final run, and then use vacuum pump to pull hard vacuum
11) crack machine open, lift bag of extract out. lay it out on a table and warm areas with a hair dryer in order to squeegee everything into one spot using a plastic card. throw the whole bag into freezer until the big cake of extract is solid enough to pull out.
issues that i am grappling with right now:
-extract seems to come out several shades darker and somewhat more gooey consistency than the same starting material does with other extraction methods.
-it takes a long time to recover 5 1/2lbs of butane, four times over. heat bath is good, i need to put my butane tank in a chilled reservoir. ideally i will upgrade and have separate tanks for filling and recovery.
-current ball valve is finicky and has started to leak a tiny amount when at 1/2 open - will probably upgrade this to a sanitary ball valve that can have the seals replaced easily
-silicone gaskets are no good for extended use, going to try out viton and buna-n
-stuffing filter discs into column is unreliable. once a suitable gasket is tested, will order one that has the right size of mesh already built in.
-need to upgrade to larger lines (current ones are 1/4") and possibly switch some parts to hard tubing in order to allow quicker and more efficient recovery / fill / vacuum on the system.
right now i am seeing 13-18% w/w yield from trim depending on source and strain. this makes my batches anywhere from 50g up to 80+g depending on what i'm running and how much i pack into the column. i am fine with this batch size for now but my next milestone is getting it so i can run a whole batch in much less time, increasing daily throughput (only 1-2 batches are practical to do in a day right now, when i have other stuff to deal with).
My system is built as follows:
-5 gallon pressure pot for the flask
- 4"D x 24"L extraction column - 304 SS tri-clamp spool section
-appion g5 twin recovery machine
-IP n-butane (99.5%) tank for the solvent
the column end caps are also 304 SS. I had my machinist tap holes into the end caps to allow me to put fittings and a gauge on my column. I currently have 1/4" brass flares (using 1/4" MPT x 1/4" FL pieces) for my hose connections, and a 3/8" ball valve for the dump line into the flask.
the column top cap has a pressure gauge ( 30"Hg to 100 PSI), two spare 1/4" flare fittings that are capped, and two 1/4" flares that are used for pre-vacuum and butane breather/overflow.
the column bottom cap has a 1/4" flare fitting for the butane fill line, and has the 3/8" NPT ball valve that dumps down into the pressure pot.
the pressure pot is completely unmodified at this point other than removing a section of handle to clear the column. it sits in a 27 gallon tote filled about halfway with water that is used to heat the system during recovery. I tried using a 300 watt aquarium heater but it was inadequate (although better than nothing). my current solution is a submersible pump that pushes the bath water through a 1/4" copper heat exchanger coil which is currently resting in a large crock pot cranked to full heat. this gives me a pretty constant 100*F bath around the flask, which I am mostly happy with at this point.
when using a scale for the tank (which is not 100% of the time), i have a tif 9010 that works great. lines are all standard hvac type lines that are rated for handling much more pressure than this system should ever see. in addition to the gauges on both the column and flask, i have a set of yellowjacket manifold gauges that control fill/recovery. altogether if you count the gauges on the appion, there are 6 different ones in the system! yowza!
my initial gasket sets were white platinum-cured silicone, but these have proven unsuitable as they expand after some period of use and will no longer even fit the flanges.
i'm using 2mil teflon PFA pail liners (5 gallon size) to avoid scraping the flask. my procedure here is to carefully slip the bag in and fold the top over the rim of the pressure pot. i then snake a vacuum line in under the bag and suck out as much of the air underneath as possible so that the bag is tightly sucked against the sides of the pressure pot. the bag does not appear to cause any issues with the lid/pot seal, and allows me to quickly and easily remove a batch from the system and reset with another bag.
inside the pressure pot i have a tube that has 200-hole stainless cloth over the end to catch any particles before they are dumped into the pot. this also directs dumps into the middle / bottom of the pot, since my column is actually dumping through a hole that is offset in the lid.
for particle filtration, i have 100-hole stainless cloth discs pushed into either end of the column (3-4 per end for safety) and then
my current running procedure is thus:
1) pack column with approx 500g of material and put filter discs into ends.
2) put teflon bag in pot, vacuum it to the pot, put lid on.
3) mount column, tighten tri-clamps and then double check all hoses and fittings for tightness and proper settings.
4) fire up the vacuum pump and pull a good hard vacuum on the whole system for about 30 minutes.
5) fill column (remember this is a bottom fil) until the top breather line feels cold - this ends up being around 5 or 5 1/2 lbs of butane.
6) shut breather and fill lines, turn on recovery machine and pull pressure pot down to 10" vacuum (this takes a few minutes)
7) open dump valve to dump butane into pot. once pressure is equal between pot and column, top breather line is opened to allow any last dribbles to make their way down.
8) turn on recovery machine, and run until it gets whole system down to 10" vacuum (with current bath temps this usually leaves 2-4 oz of butane still in the system).
9) repeat steps 5-8 another 3 times - for a total of 4 butane soakings
10) allow appion to pull all but the last 2oz of butane back into the system for final run, and then use vacuum pump to pull hard vacuum
11) crack machine open, lift bag of extract out. lay it out on a table and warm areas with a hair dryer in order to squeegee everything into one spot using a plastic card. throw the whole bag into freezer until the big cake of extract is solid enough to pull out.
issues that i am grappling with right now:
-extract seems to come out several shades darker and somewhat more gooey consistency than the same starting material does with other extraction methods.
-it takes a long time to recover 5 1/2lbs of butane, four times over. heat bath is good, i need to put my butane tank in a chilled reservoir. ideally i will upgrade and have separate tanks for filling and recovery.
-current ball valve is finicky and has started to leak a tiny amount when at 1/2 open - will probably upgrade this to a sanitary ball valve that can have the seals replaced easily
-silicone gaskets are no good for extended use, going to try out viton and buna-n
-stuffing filter discs into column is unreliable. once a suitable gasket is tested, will order one that has the right size of mesh already built in.
-need to upgrade to larger lines (current ones are 1/4") and possibly switch some parts to hard tubing in order to allow quicker and more efficient recovery / fill / vacuum on the system.
right now i am seeing 13-18% w/w yield from trim depending on source and strain. this makes my batches anywhere from 50g up to 80+g depending on what i'm running and how much i pack into the column. i am fine with this batch size for now but my next milestone is getting it so i can run a whole batch in much less time, increasing daily throughput (only 1-2 batches are practical to do in a day right now, when i have other stuff to deal with).