Chapter 1 ended with the test sled ready for trials and I reported my successes using aluminum beads in leu of water for sous vide cooking:
Alas, my success thus far cooking at low temperatures under vacuum is limited to one success and also identified flaws and needed upgrades to the test sled. After trials to establish boiling points of water and alcohol under vacuum, the modified pressure cooker that I was using, lost seal integrity, so clearly the seal was not neoprene, nor compatible with hot ethanol.
In the spirit of repurposing where ever possible, and as extracting some of the terpenes and flavonoids involve using ethanol, that led me to sort through the sanitary equipment that I have on hand, and to cobble together a 0.7 gallon welded bottom 6” X 6” sanitary spool, a 6” X 6” sanitary spool to extend it to 1.5 gallons, and a welded bottom 12” X 12” sanitary spool holding 5.7-gallons.
New 12” X 12” & 6” X 6” + 6” expansion spool pots, including 12” X 6” end cap reducer allowing common lids with controls and plumbing
I had all of the parts I needed for the 6” systems, including a 6” lid from my original prototype Lil Terp BHO extractor with the required plumbing, so rather than build a separate lid for the 12” spool, I elected to use a 12” X 6” sanitary endcap reducer with PTFE seals, which allowed me to transfer the 6” lid back and forth.
Alas, the only thang is that I didn’t have was a 12” X 6” sanitary endcap reducer, but as a seasoned scrounger, I initially borrowed a Transforminator lid from kindly Carla Kay to keep the project on track, but kept looking, and imagine my joy and amazement when Glacier Tanks in nearby Vancouver, WA was gracious enough to accept one of my plain NOS 12” lids back in trade for the reducer that I purchased from them in 2015.
A nice gesture from a good place to find sanitary parts for the botanical extraction and brewing industry.
My first vacuum cooking experiment was Jalapeno Lemonade, which required alcohol recovery and so I used the EtOH Pro on loan, alas to find that I contaminated the internal plumbing with Jalapeno flavonoids and capsicum, requiring multiple flushes with clean 190 proof, which was then contaminated and limited in use.
Sooo after getting the EtOH Pro clean again, I decided to add my own condenser system that I could dedicate or more easily flush.
In that regard, I added two condensers to the test sled, one a fan cooled copper tube radiator and the second a 50’ ½” copper coil in a water or ice bath.
The radiator is a single copper tube 10 pass heat exchanger with aluminum fins built by Derale, with a 12 VDC cooling fan scavenged from a different Derale fluid cooler.
The radiator heat exchanger can be used to remove water vapor from the discharge, so doesn’t require a hood to capture the steam indoors. It can also be used alone or in conjunction with the water bath coil heat exchanger for recovering alcohol.
The water bath coil is capable or recovering alcohol on its own, but uses less cooling water or ice if the stream is primarily liquid when it reaches its inlet.
Vapor to air and Vapor to Liquid Heat Exchangers
The two heat exchangers can be used individually or in series. In series ostensibly the vapor -to-liquid exchanger could use simple cool tap water instead of an ice water bath, for an operational savings.
Hooked up to top radiator only
Note that in the upper configuration, the ½ gallon canning jar cold trap in the center of the above photo, can be placed in the water bath condenser pot with ice as an further variation.
In series with jumper
As you will note in the above photo, the ice bath tank drain has only a bar to attach a hose, which I found adequate and as it is gravity drain, allows me to temporarily slip a length of hose over the barb and drain the tank outside, without rolling the test sled outside to drain.
My experiments recovering alcohol using both the EtOH Pro and the Essential vacuum stills suggests that the stripping run from a wash under vacuum, produces about 130 proof. I ran five successive runs to get it to 185 proof and then used mol sieve to get it to 190 proof.
Since my new system accommodated sanitary parts, I decided to combine this experiment with my compound refluxing still experiment, so added the column from my previous experiment at the following link, in an attempt to reach 190 proof using fewer runs:
The 2” X 36” refluxing column is made from a sanitary spool stuffed with stainless steel ribbon pot scrubbers repurposed for use. As shown it is un-insulated, but in use it will be covered with pipe insulation and reflective tape. As this is an experiment, it may be necessary to lengthen the reflux column to reach 190 proof azeotropic balance concentration. Super easy to do in 6” up increments using sanitary tubing spools.
Stainless steel ribbon packing in reflux column
Reflux column with 6” control and plumbing lid on large pot
Thermocouples in Pot and Column Head
To produce a double boiler effect, the 6” diameter pots sit in the Wyott soup pot full of the aluminum beads donated to the project by Cascade Scientific, and the 12” diameter pot goes into a 16” diameter baking pan full of aluminum beads, which sits on the Thermodyne hot plate.
The thermocouple in the pots controls process temperature via a PID controller, and the thermocouple in the column is read only, but utilizes a twin PID controller to provide process feedback.
Twin PID’s for Process Control and Feedback
6” Pots in Aluminum Bead Double Boiler For Even Heating
12” Pot in Aluminum Bead Double Boiler For Even Heating
As many of my food flavor experiments involve solids removal, in conjunction with the difficulty cleaning the interior surfaces of my Buchner funnel, I decided to also add an easily cleaned vacuum filtration to the sled, using sanitary parts.
In keeping with the spirit of repurposing and my toy budget, I was again able to use mostly parts left over from WolfWurx, or my original Mk III Terpenator and the Lil Terp prototypes.
Not as professionally done as the system I tested on the Medxtract Essential, but it works using mostly surplus parts.
The Terpenator parts that just keep on giving, even though I can no longer use them legally for BHO extraction outside a licensed and permitted extraction facility.
Vacuum Filtration Assembly Conceptual
What I didn’t have was a 6” PTFE 100 micron screened gasket or a filter plate to support it. I found this $69.00 FP-6IN filter plate kit at USA Labs that included the 6” tri-clamp filter plate, a 100-micron screen, and a retention ring which in addition to its utilitarian charms arrived expeditiously:
USA Labs 6” Tri-clamp filter plate with screen and ring
25 Micron and #1 Lab filters cut using the filter retaining ring as a template
Vacuum filtration assembly on small pot
Seals and Hoses:
Because of the possibility of seeing hot ethanol vapors, all of the seals and hose used in the hot sections are PTFE, and the hoses between the pump and the liquid cold traps are nylon lined refrigeration hoses.
The PTFE hoses in the hot sections are all 3/8” with 304SS stainless over braid, using stainless 3/8” female #6 JIC ends, mating to stainless male JIC flare connectors. I obtained those hoses and the JIC fittings from Associated Hose, here in Portland.
I used Viton gaskets in the vacuum filtration unit, as Viton is compatible with ethanol at ambient temperatures and is more resilient than PTFE.
I used lead free brass bulkhead connectors in the liquid trap lid on the cool side of the heat exchangers, and both the radiator and the water bath coil condenser are copper.
Hee, hee, hee, currently awaiting a couple final parts and then ready to proceed with the culinary experiments!