Yeah, Swim has dreamed about cooking gear via H3PO3 with a push-pull unit and ghetto condenser.
There have been some modifications...
To bee honest, after a year of thorough experimentation, phosphorous acid alone just doesn't cut it (using a PP unit) At least in Swim's opinion.
It is like gambling every time he decides to run a batch. He never knows if the pseudo will fully convert.
About 50% of the time it will and 50% it will end as a partially reduced product. Best results are found using a ghetto condenser with balloon. This keeps the HI contained.
On the other hand, Swim prefers a PP to a balloon for larger rxns.
It has become either run smaller rxns with a balloon (and longer rxn times) or larger rxns with a RP kicker.
Swim now uses .25 pts of the recommended ratios of lab grade RP or .5 of the recommended ratios of MBRP in conjunction with phosphorous acid to make sure that proper recycling is initiated.
The problem with PA is that it will run good and strong up to 3-4 hrs, after that it will continue to react but it becomes blatantly obvious that the percentage of HI in solution falls to below the 57% mark and the rxn begins to slow or often times die. Most would assume, "its not reacting therefore it must bee done" ...NOT
PA has a recycling problem.
JohnDee recommended using RP with H3PO3 as a kind of "hybrid" rxn and he has never had any nightmares since.
Swim runs 1E, 1.4 I2, 1.4 H3PO3 and either .25 pt lab grade RP or .5 MBRP with .6ml dh20 per g of pseudo.
Using RP as a kicker, one does not have to use heat and wait for the 73 deg C magical temp before HI is produced.
The RP will kick it off without heat and Swim allows it to react without heat until heat becomes absolutely necessary. He believes that is the problem he was having using H3PO3 solo (without RP) he would bring the temp up fast and in the process send all the HI gas into the PP unit where it becomes lost and unavailable to the rxn. Less HI in the flask means less reduction.
He will then SLOWLY bring it up to 110C and leave it there for 18-24 hrs. (Or whenever PI3 crystals are observed in the hose whichever comes first) Takes about an hour to hour and a half to reach 110C...
Swim uses a 1000ml florence submersed in an oil bath with a #7 stopper and 1/2" braided PVC hose that comes up about a foot and is fed into a 2 1/2 gallon bucket. The hose is fed into the bucket from the side about 2" from the bottom and up through a hole cut in the lid.
The hose comes up about 1 ft from the top of bucket and is then connected to a push pull unit (consisting of 2- 2 1/2 gallon gas cans)
The second can has a hose that is then fed into a plastic whiskey bottle full of silica gel kitty litter.
The 2 1/2 gallon bucket condenser is filled with "pre-chilled" blue artificial ice bags to keep it cold. (Swim has tried using regular ice but it melts too fast, and the hose leading down to the flask must bee wrapped with a towel to prevent a potentially hazardous incident) The fake ice lasts 3 times as long and leaves NO mess and minimal condensation.
Big bulky setup, but it works.