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SaltyNuts

Platinum Member
May 1, 2001
2,353
253
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uclalabrat, you sure help a lot for somebody that refuses to help.

SILENCE YOU FOOL! We are doing the good Lord's work here. He said he wasn't going to help me on that other part because he was worried I was going to blow myself up, and he did not.

Now I've got some learning to do about vacuum distillation and available devices out there LOL.

We are taking this straight to the TOP!!!!
 

uclaLabrat

Diamond Member
Aug 2, 2007
5,218
2,094
136
uclalabrat, you sure help a lot for somebody that refuses to help.
I'm much less concerned about him doing a vacuum distillation. That's sufficiently complex and expensive that it has its own natural barriers.

The thought exercise is fine. And when shit goes south it will implode, not explode.

At least at first.
 

IronWing

No Lifer
Jul 20, 2001
64,648
19,037
136
Having walked into the lab the morning following an implosion of an improvised vacuum vessel, no thanks. The grad student who triggered the implosion was lucky enough to have been out of the lab when it happened. Shards of the pvc water main used for the vessel were buried in the cinder block walls of the lab. It turns out that in an implosion, the stuff keeps moving past the center point.
 

skull

Platinum Member
Jun 5, 2000
2,205
326
126
Having walked into the lab the morning following an implosion of an improvised vacuum vessel, no thanks. The grad student who triggered the implosion was lucky enough to have been out of the lab when it happened. Shards of the pvc water main used for the vessel were buried in the cinder block walls of the lab. It turns out that in an implosion, the stuff keeps moving past the center point.
Thats the result of a chemical reaction from the vacuum right because your making it sound like it was just the vacuum? I pull vacuums on copper tubing all the time, down to about 200 microns. Never seen anything even suck in so much as implode from vacuum. PVC drain pipes can handle like 200 psi, vacuum can put at most atmospheric pressure on the outside of the pvc, which is only 14 psi. No way I see it imploding the pvc enough to send it past center to the other side of the room.
 

IronWing

No Lifer
Jul 20, 2001
64,648
19,037
136
Thats the result of a chemical reaction from the vacuum right because your making it sound like it was just the vacuum? I pull vacuums on copper tubing all the time, down to about 200 microns. Never seen anything even suck in so much as implode from vacuum. PVC drain pipes can handle like 200 psi, vacuum can put at most atmospheric pressure on the outside of the pvc, which is only 14 psi. No way I see it imploding the pvc enough to send it past center to the other side of the room.
Volume x Pressure. The PVC water main was about 16 inches in diameter. The experiment used a double vacuum vessel with a pump inside the pipe pulling vacuum on a smaller vessel. There were real good reasons for building it this way. The first and foremost was that the professor in charge was a theorist with almost zero lab experience who told his students to go figure stuff out so they did. Same professor had to pay to have the drain pipes in the lab replaced after a student poured strong acid down them. He also had to pay to decon his lab for mercury because he had a scheme for measuring soil porosity by using a suction pump to induce mercury flow into samples. The mercury pump sat wrapped up in the lab for three years+ I was there while the university risk department tried to find a landfill/recycler to accept it.
 

skull

Platinum Member
Jun 5, 2000
2,205
326
126
Volume wouldn't matter in rupturing the pvc, the pressure can only be as great as atmosperic presure pushing on it from the the outside. Was he using the green drain pvc and not the white pvc? Green drain pvc isn't pressure rated and its real thin so I could see 14psi imploding it.
 

SaltyNuts

Platinum Member
May 1, 2001
2,353
253
106
OK Lab Rat, I am having some real problems on this whole vacuum distillation thing. Everything has to be so darned complicated...

So, linoleic acid boils at "231 °C at 1.70E+01 mm Hg", so that (low) pressure is my bogie.

I use google and that 1.70E+.01 mm Hg thing looks like it translates to millimeters of mercury at standard atmosphere or something like that. That, including the whole formula with the E and the plus 0.1 thing means absolutely nothing to me LOL.

I plug in "1.70E+.01 mm Hg" on this converter:

https://www.convertunits.com/from/mmHg/to/atm

And it truncates that to 1.70E01. I have no idea whether that is right. But then that converter spits out .022 atm, which I assume is .022 atmospheric pressure.

If that is right, how hard is it to get something down to .022 atmospheric pressure? If normal atmospheric pressure is 1.00, it seems to me .022 is a very, very big reduction!

And the pumps its really hard to tell what pressure they will get you down to. Here is a cheap one:

https://www.amazon.com/Homesprit-Filtration-Laboratory-Distillation-Apparatus/dp/B083Z98JKH/ref=sr_1_5?keywords=vacuum+distillation+pump&qid=1638056598&sr=8-5

I would have guessed since its so cheap no chance it would do the trick, and consistent with that I do not see any kind of pressure rating in its description. But them I look in the reviews, and one of the first ones says that, under the "UPDATED", that this pump could only pull -7 Hg. Well when I use that link above but put in -7 Hg I get -.23 atmosphere, here is a link:

https://www.convertunits.com/from/in+Hg/to/atm

NEGATIVE atmospheres, is that right? Is this one indeed far and away powerful enough to hit the 0.022 atmosphere metric?


Then there is the glassware kids and what not. You have something like this:

https://www.amazon.com/Suction-Filtration-Distillation-Apparatus-Buchner/dp/B081DKR1CV/ref=sr_1_4?keywords=vacuum+distillation+kit&qid=1638058235&sr=8-4

It indeed has a hose for a vacuum pump it looks like, but it seems it has a glass filter between the top and bottom pieces, and the vacuum is just supposed to help pull stuff from the top to the bottom? Not a true vacuum distillation device like we need, is it?

THIS is something like I am looking for, correct?

https://www.amazon.com/Distillation-Apparatus-Equipment-Chemistry-Glassware/dp/B07R8JFK97/ref=sr_1_3?keywords=vacuum+distillation+kit&qid=1638058235&sr=8-3

That, big enough pump, a stands with clamps, and I should be good to go correct? Or is that too flimsy to take the pressure without imploding?

Any thoughts on what I need are greatly appreciated Lab Rat!!!!
 

SaltyNuts

Platinum Member
May 1, 2001
2,353
253
106
Hey Lab Rat, I'm going to guess you know what this device is? :) SHIT. IS ABOUT. TO GET REAL!!!!!!


20211203_210606.jpg
 

SaltyNuts

Platinum Member
May 1, 2001
2,353
253
106
Oh heck yea it is Lab Rat LOL. I got more goodies on the way too... stay tuned to this Fat Channel!!!!
 

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