So this graph illustrates the compressibility factor of different n-Butane/Nitrogen Mixtures. The % is %n-Butane.
As you can see, the compressibility factor decreases as the butane concentration increases. I haven’t taken the time to go through calculations of the real gas scenario—but this is where that stuff becomes important.
I’m almost certain that continued nitrogen compression cycles (especially pure or high% nitrogen) will lead to premature failure because the pump must utilize more force to complete a stroke…since the force of the stroke is already set, it’s more like the diaphragms are overexerted when trying to compress the nitrogen and so fail prematurely.
The piston based pumps like the Cmepol have a 450psi cutoff. Running them up to 150psi pushing n2 doesn’t strike me as problematic. OEM test procedure includes shutting outlet and pumping air till shutoff.
For the diaphragm style pumps, you’re running 70% N2 on the other side of the diaphragm, which would seem to me to offset any N2 On the business side.
Because dumping your 100lb solvent tank with 80psi n2 then trying to recover all the solvent AND the N2 back into the tank simply won’t work. And the manufacturers are certain we’re all idiots.
My solution was a second tank for the N2. Recover into -50C tank, pull gas (N2) off the top of that tank and store in second 100lb tank. Used the same N2 push for a week**. Setup should have had a HX on the Cmepol to keep the N2 pressure down. 100psi would turn into 150PSI when it was warm.
This pulled some propane over into the second tank. But with 100psi in there it was trivial to move that liquid back into the primary solvent tank.
**system was only up for a couple of weeks before being moved. Working on getting it back up.
I got some actual pictures from the ebay guy - different from pic I’d posted earlier - and I’ve not seen clamps like that on the collection chamber. What do you think?
Thanks @Killa12345,
Go right ahead and hate, if it’s not safe fair enough. I respect you & the other folks on here’s opinions.
I’ve not bought it so right now it’s all just increasing my knowledge.
If ud add the nitro directly to the solvent tank and the lines open itll do the rest. you really gotta throttle then. my crc throttle my speed pretty good.
im just ready to get these past few parts I need for racking it
We pumped a heck of a lot of n2 with the passive system we made years ago, pump didn’t seem to mind.I think they are warning about pumping n2 because of customers potentially over pressurizing their solvent tanks.
I bought all my stainless from the USA … From a distillery shop. I would advise you pay Killa and suffer some import tax. At least you know what your getting and you have support .
