While I first shared the Terpenator design on 2-7-2011 on both SPR and IC Mag, and subsequently the fully automated Mk II, it was really the manual Mk III shared on 9-19-2012 that gained a foot hold and went viral. 


It was also the design that I subsequently expanded into the Mk IV and V and was the basis for numerous emulations by others using the general Tri clamp sanitary fitting design. 

The Mk III holds about 150 grams of plant material in its 1 ½ X 24” column and produces about one ounce of concentrate per run, making it an excellent size for personal use, but is fast enough that we used it for bulk extraction before developing the Mk IV and V.

Between then and now, numerous process improvements have evolved so it’s time to retire the older Terpenator design and move on to the Mk III Evolution embracing the process innovations by me and others.  The same upgrades could be made to a Mk IV and V, but I will focus only on the Mk III as support to individual medical cannabis patients and small groups sharing equipment.

The Mk III design itself was simple and straightforward, lending itself to both passive and active recovery, and the Mk III Evolution follows that tradition so as to keep costs minimal.  I’ve also designed some ancillaries to work in concert with the Mk III, which are frosting on the cake for those who elect to build a Mk III or larger system for themselves.

Improvements made:

  • Starting with the Mk III lid, I moved the column from the center of the lid, to one side, thus providing room for a 2” sight window, so that the process may be observed, making early pours and products like Cotton Candy easier to control.
  • I also modified the column, to include a 6” jacket in which to place dry ice and an antifreeze mixture, which includes a wrapped coil heat exchanger for pre-chilling the LPG as it is injected.
  • Here is a design for a simple heated shatter platter:
  • I designed a stainless holding tank for the LPG, that is robust enough for 100% propane and holding more than 5 column volumes liquid. It drains from the bottom, thus eliminating the dip- tube and has a vapor port in the top along with a PRV.  The unique part of the design is that it also includes a heat exchanger coil for pre-chilling the LPG before it is injected.
  • Here is the counterflow heat exchanger we used to cool the recovery stream and 
  • had would using 20′ lengths of 304SS tubing and modified Swagelok fittings.
  • Besides cooling the recovery stream, the system needs a means to protect the pump from shots of liquid, as well as remove any accumulated moisture.  Here is my original Cyclone Filter Drier design using dual H-48 Zeolite cartridges and a cyclonic intake to prevent direct liquid impingement on the filter elements.
  • Depending on the LPG mix and the temperature, additional injection pressure may be required, so I’ve designed a couple of options that sidestep the need for Nitrogen assist, by heating LPG to obtain the required pressure and then applying a pressurized stream from that tank to the head of the chilled holding tank. 

         Unlike Nitrogen, which must be burped with attendant LPG losses, pressurized LPG can be recovered along with the chilled tank with no burping and attendant losses required.

  • To heat the high pressure tank, as well as the Shatter Platter, I’ve designed an inline hot water circulation system, controlled by PID and circulated through the shatter platter assembly and which can be dialed up and used to heat the columns to drive out residual LPG under vacuum, so when back filled with nitrogen, as to be below 10% of LEL. 
  • Lastly, subzero pumps are expensive, typically mag drive to eliminate the polymers that lose their resilience at subzero temperatures. I designed a two-chamber pump that circulates the antifreeze at subzero temperatures achieved by adding dry ice, between dual chambers, using air pressure, with the heat exchangers in the circuit between the two chambers. 

     Here is a conceptual showing an assembly of the above components , plus some I will share shortly:

Note that by manipulating the two three way valves between the cyclonic filter drier and the counter flow heat exchanger, you can recover either passively using only the heating and cooling systems, or with the optional recovery pump.

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