Hey Guys, I’m getting my venturi pump in the mail today, i plan on using it just to vac out the N2 out of my solvent / recovery tank, after injection, before recovery.
When i pull this vac on my solvent tank it will still have some solvent in it, how low should i vac the tank?
Will it go down to -29.5 with solvent in the tank (obviously it will be cold, DI / ISO bath) or only go down to 0?
thanks to all you helpful guys here, my system is about to be complete!
What venturi pump did you get?
I believe I got the one that you suggested on some thread on here.
@Dred_pirate (it didn’t show on my screen as a response to your question, my bad if you got two notifications
No fret man.
I would pull to about 28. And if you empty the tank for a run, you can vac the crap out of it before recovery.
When you release nitrogen, vent it outside, or into the exhaust. Close it before it stops emitting any nitrogen, but don’t let it go to zero and pause. The tank can suck up moisture. Vac it down after you vent it and resume. Also, when you push nitrogen over from the material column and it makes it to your collection/evaporator. You’ll end up recovering a small nitrogen that way. Don’t vent it from your boiling collection pot. Remove it from your tank if it raised too much pressure and slowed you down. I would stop recovery, wait a moment to make sure everything in the tank has condensed, remove access pressure, then continue.
What air compressor are you going to use for the venturi?
I’ve been looking into this one
What size compressor do you think this would take? I planned on a 120 gallon.
That would be more than sufficient. These pumps only require a small cfm rating. The tank just keeps the compressor off longer
Tell me you shop at open source steel, without telling me you shop at open source steel.
And the tank size doesn’t really matter. As long as it has enough cfm to drive it.
And they don’t say what they require, which is weird. I like these to an extent, but they break easily and I think are more expensive than Cole Parmer ones.
Lol I wasn’t planning to buy it from them. They were just the first place I had seen a large one.
It being larger than the Cole Parmer doesn’t change much. It has roughly the same vacuum capability. It just pairs well with a haskell because you already had to buy an air compressor to push the haskell and that’s how ets sold them.
The CP is also a metal body that won’t break as easy. Plumb a hose to the exhaust (npt) to lead to your fan out and you won’t have to hear it
OK sorry guys, I’m waiting for starlink to hmu with the reliable interwebs. Rn my internet connection goes out when it rains, storms, the earth rotates, things like that.
Now this is the pump I have coming along with it: https://www.amazon.com/dp/B09126QW77/ref=cm_sw_r_cp_apa_glt_fabc_0SS32A4GMPDE9NE3D9E2
I actually called Cole Parmer and they said “any pump would do”. Hopefully this will work otherwise I’ll be heading to the store 
That probably won’t work. They have the air requirements on the site. @ 80 psi it needs 4.8 cfm
I kinda knew that would be the case. I appreciate your input. I’ll give it a shot on an something empty and go from there. Thanks for the tips man!
Also, I know ppl go through these threads a lot, so if you’re reading this and order the venturi I did (EW-78165-30) cole parmers website is wrong, the vacuum port is only 1/8" not 1/4" FNPT. So you’ll need a 1/8" MNPT to 1/4"(or whatever size your set up uses) FJIC adapter. Such as this one here: https://www.discounthydraulichose.com/6505-02-04-18-nptf-male-x-14-jic-female-swivel.html?gclid=Cj0KCQjw_dWGBhDAARIsAMcYuJz_avjkdRsAr9qo9R2sRmFuIPm8ENU8MUeUd0ORBd_b3LGOGAN9mFIaAjgOEALw_wcB
Also wondering about correct use of a Cole-Parmer Venturi Vacuum Pump (1.2 cfm, 28"Hg).
Received a previously used solvent tank with n-butane/propane mix and possible nitrogen leftovers (which obviously has positive pressure at room temp).
Ordered a CP Venturi and would like to confirm that these the correct steps (below) in order to pull vac with it?
1)put tank on dry ice, cool down below evaporation temp of solvent mix.
2)If nitrogen is left, and positive pressure remains, release pressure until slightly above 0.
3)Then start compressor/venturi vac pump and vac down to 28.
4)Solvent mix is now ready to use (?)
When using nitrogen to push cold solvent, should one also release nitrogen and vac down the recovery tank like described above, before going into full recovery mode?
I fucked up and undersized my compressor for my piab, i put a valve on the air in line and only open it about 30% to get the bulk of the vacuuming done and at the end just open the valve all the way to get to full vac. Its not ideal but it works and the compressor keeps up fine. Im gonna get the cole palmer soon to replace it as it seems much better and needs less cfm
My compressor is 6.2 cfm @ 90psi btw.
You’d be better off removing all of the solvent in the tank, venting to zero psi, then cleaning it thoroughly. When you put it back together, pressure test it to make sure she’s nice and sealed. Then when you vent the pressure out the vapor ports, I’d give it a sweep through the dip tube and let it run for a moment (yes you’ll use a bit of nitrogen, but that’s cheap.), turn off nitrogen and close it when it minimal pressure left. Now heat the tank and pull vac while it’s nice and hot. Then let it cool while pulling vacuum and get it down to as cold as you’ll use it.
Might as well change your sieve beads, then redistill your solvent. For shits and giggles, change them out again.
Don’t forget to remove the nitrogen from the tank that possibly made it into the collection or wherever you were holding it.
Ooooh. I like that trick with vacuuming the solvent tank hot.