During the time frame that I introduced the Mk III, I introduced the Lil Terp Passive extractor, which was based on the Mk III design, but was actually not my first conceptual for passive extraction and collection.
The first was based on another of FOAF's post where he did a passive recovery and looks like I downloaded it 7-22-2010 at 9:55AM:
FOAF’s passive experiment
Here is the first design, that I never built, and looks like I didn't date the conceptual. When the Tamisium came online with a nice design CNC turned out of a single billet, but priced out of the market for ma and pa, I came up with the Lil Terp design, based on readily available parts.
And another design in 2014 made of borosilicate that I also never built, because I couldn't find thick enough borosilicate to meet 350 psi ASME requirements for LPG. We Investigated using available 9mm wall and clear PTFE coating it for strength, but abandoned the idea and moved
And here is the first Lil Terp, that did get built, which was based on the Mk III:
Lid machining detail for Lil Terp
Lil Terp conceptual
Lil Terp ready to extract
Weld quality by Gibson Welding
The welds were done by Gibson Welding, and looks like stacks of shinny new coins. I cut a 12" long spool in two pieces and made new 1/2" bottoms for it, using blanks from BBC Steel in Canby, OR, which were machined by Moody Machine Works in Milwaukie, OR.
Subsequently welded bottom spools became available, as well as 6" spools, so that you can use a clamped end cap for the tank bottom.
Here is the cost to build the Lil Terp at the time. As you can see it was under $650, which was a price ma and pa could better afford.
Bill of Materials
As it came to pass, a reader brought by Tamisium TE-175 seeking process support and we were able to run it alongside the Lil Terp. While the Tamisium is a fine machine, it didn't produce more material or provide a better return.
Lil Terp in shootout with Tamisium TE-175
We subsequently tested the Best Value Vacuum's new ASME certified offering and their Mini extractor with about the same good results. Within design limits, it appears to be the process, not the equipment that accomplishes the end result.
BVV ASME Certified Passive extractor
See more history at: https://www.icmag.com/ic/showthread.php?t=240005&highlight=Passive+Butane+Extractor+reclaimer
Here is a commercial sized Koolinator Passive extractor conceptual that I never built. It pumps coolant or hot water to the different components, depending on their needs.
The only pumps are coolant, hot water, and vacuum. All recovery is done passively.
Koolinator Essential Oil Extractor