Boiling Mercury to Create a High Vacuum - Mercury Diffusion Pump
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- เผยแพร่เมื่อ 1 ต.ค. 2023
- Diffusion vacuum pumps are captivating devices that operate without any moving parts, yet have the ability to reach high vacuum levels. Nowadays, diffusion vacuum pumps, especially those utilizing mercury, are rarely employed. That's why I thought it would be intriguing to showcase a mercury diffusion vacuum pump in action in a short video today.
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Ever since I've heard of these I have wanted to see a glass version.
Applied science also has a video showcasing a glass diffusion pump
very cool to see a glass Mercury diffusion pump in action! thank you for taking the time to share this with us.
It should also be possible to make a diffusion pump work with alkali metals. Not practical, but possible. It would need extra valves and probably some way to continuously purify the metal.
Yea same with cannabis distillate.
What an insane idea! A potassium or cesium diffusion pump would be a spectacle! I like it!
@@AdvancedTinkering It's especially cursed because iirc almost all the pumping function is already available if you don't go to so much trouble and leave whatever alkali metal contacting chamber to only act as a getter pump.
Vapor pressure must be checked.
@@papanyanz All the alkali metals have uniformly lower vapor pressure than mercury. Cs is closest In the relevant pressure range a Cs-rich diffusion pump would run 100-140 C if it were only diffusion pumping. In reality it's also acting as a getter, so it might run somewhat cooler.
Fascinating. Thank you for all the trouble to set up and demonstrate this.
A very nice demonstration of the working principle.
Very nice! Never seen one of those in action.
The biggest advantage to that pump is that if the system goes to air for any reason, you don`t have a ruined pump (turbo-mol) or a sticky mess to clean out that may be impossible (oil-diff). For some applications, I still use one of those but mine is metal cased.
Are there any other performance/cost related advantages aside from an easier cleanup when there's an event?
@@PoseidonDiver Yes. Since they are not detrimentally effected by air exposure (other than momentarily losing high speed pumping), you can skip the (very expensive) high vacuum valves needed for bypassing turbo-molecular or oil-diffusion pumps to allow rough pumping of the system (and the hazard that someone will forget to bypass and destroy the pump). This is a large advantage for chemical synthesis, where many flasks may need to be evacuated in sequence and many experiments done in a day. For large chambers that are only opened and closed on a daily basis, not so much. Also, since you are already observing mercury handling protocols, mercury manometers and McLeod gauges (sort of a combination liquid-piston compressor and manometer) can be used for pressure measurement, eliminating the need for electronic gauges and associated calibration and maintenance issues.
The high molecular weight of Hg contributes to greater efficiency.
@@keithjurena9319 *Atomic weight. Elemental mercury doesn't have distinct molecules.
@@keithjurena9319 That is so true and not thought of by many. This needs to be considered when people suggest using metals like sodium in a pump. And,..sodium being so reactive it would greatly limit its uses. I suppose you could even say that a sodium diffusion pump would `getter` itself!
Nice to see one of those in working order. I only ever heard that they were used in the past, but trying to get one for UHV seems to be basically impossible...
Diff pumps with mercury are interesting if you want to pump radioactive gases as (depending on the radioactive isotope) they can attack most oils ang cause them to degrade. In particular, mercury diff pumps got interesting again for fusion with research on them being done for ITER.
I and some colleagues also wondered if you could do the same with Gallium as well as a less toxic medium with lower vapor pressure. The pump would probably need to be made of something not wetted by it like Quartz, or coated with something Gallium oxide. Higher vapor pressure would also mean you'd have to heat it more on the evaporating side, so maybe that might become the issue.
Gallium has way to low a vapor pressure I would guess. Unless you are talking red heat I don’t think it would work.
Guttsy video, thanks for the bravery,... PS I instantly could see you would not get to super low vacuum when I seen the silicon couplings. Took me 6 months to realise how permeable silicon rubber is at just 0.5 atmospheres. In fact it would be interesting to see if you dumped the glassware and use silicon rubber tubing as your check valve and boil oil.
Ever since reading Procedures in experimental physics by John Strong from 1938, I have wondered if any of this type of equipment is still around. Glad to see it is.
MDPs are so cool! Thank you for showing it working.
Wow less then 24 hours to edit the video. Great job!
Great Video.
The forbidden bong!
I hate to be the glass's blower trying to make those fancy glasswares? I always heard of Mercury Diffusion Pump? But what is it used for (?) in chemistry?
Interesting, I've worked on one or more of these ! In our "Control Room Area" we had 30 Sub-Station (3.75 miles apart) with Mercury-Arc Rectifiers (Metal clad, Water Cooled, 12 Anode, 2 stage Vacuum pumps) ( Side Note: had 2 enamel bucket full of mercury in the Cathode Base and also the mercury will turn to a dirty grey sludge around the electric heating element)
Working Range - 12 Phase 900VAC in, 750VDC out, At a Max Constant-Load aprox.. 4000 Ampere.
The Commissioned Lifetime 1935 - 1970's changed out for Germanium then Silicon (+2) in S/stn's
Yes, my Medical Record does show having worked with Mercury as well as Asbestos, "Verdigris" is my Achilles heel my eyes stream on air-born contact.
(and NO I and no amount of help, "have ever" lifted a bucket of Mercury, they gave us a enamel ladle and standing inside a rectifier you get bored when your young. 😁😁)
im not quite sure, but i think i saw that pump on ebay not too long ago and thought, mhh what crazy man would buy that...
Ive just discovered uour page and its brilliant, have you ever came in contact with an old mercury rectifiers
Thank you! I appreciate it! I've seen them in videos but never in person.
ahh my favorite vacuum pump..
Wo hast du denn die Flasche Quecksilber her ? 😅 die ist doch mit Sicherheit 30 Jahre alt oder 🤔
Edit: gerade geschaut, die Postleitzahl Reform war 93 also muss die Flasche von vor 93 sein 😮
"Altbestände" ;)
@@AdvancedTinkering wird ja nicht schlecht son Element 😂
"Mercury poisoning to Create a High Vacuum" I have a good ol fashioned Edwards Diff-stak ... the oil for that thing costs an absolute fortune!
Serious question - what are the chances of mercury vapor exposure when using one of those?
If they are used correctly the risk is negligible. But if something goes wrong (breaks for example) that's a different story.
And I definitely would not use mercury in a diffusion pump meant for oil.
@@AdvancedTinkering I love how you added the lil disclaimer to not use mercury in an oil diffusion pump. 😂 I may lack all sensibility by spending a small fortune on an Ultra high vacuum system I hardly use, but thankfully am sensible enough to nope the fuck out of vaporized mercury l!
@@PoseidonDiver If you are new to diffusion pumps, there is a very high chance that you will allow your pump to draw in air uncontrolled, like a tube come off or break maybe. This will instantly (nearly), trash an oil diffusion pump, resulting in a pump body full of sticky goo. This is not a worry with the mercury diffusion pump as mercury is unaffected by air, (very slow reaction), even at its boiling point. So your pump would be safe. You just need a cold trap on the outlet to the roughing pump. It`s case of different pumps for different purposes. In my applications there was a very real risk of the system going to air. Also the vapour pressure of mercury was not a concern, my vac was not ultra-high.
@@TheTemporalAnomaly yep, I've actually owned one for about 3 years but have just not had the time to even assemble the system. Work commitments have eaten away all my hobby time which sucks. But yes, I am very much a 'backroom chemist' that just really enjoys having fun with the natural sciences.
I am totally "that guy" that will make all the mistakes due to not having formal training. Fortunately I am autodidactic enough to always be safe with what I do, probably just run into higher costs as a result more than anything.
My interests have mostly been around extracting compounds from medicinal plants (I live in South Africa, we have a wide range of medicinal plants, it's really interesting)
But it's people like the Thought Emporium and Applied Science that planted the seed with all the fun one can have with ultra high vacuum 🤣
Mercury is my favourite element I have about 200g of it I am a very science type guy.also can you please make quantum dots it's pretty simple in my opinion all you need is urea and citric acid
If you put a oudin coil to it the vapor patterns of the mercury vapor inside will glow allowing you to see as the pressure changes.
This is kind of an amazing idea. I would bet using the mercury l line for illumination at 365nm from a black light tube in a darkened room and with a fluorescent screen behind the setup would also allow the vapor flow to be observed.
edit: in fact come to think of it, a simple germicidal lamp where the emission lines are sharper than the uv phosphor emission on a black light bulb may work even better.
What an interesting idea! It's a pity that I didn't think of exciting the mercury in the gas phase.
I want to leave just leave the pump running on my table as a beautiful conversation piece :) but i dont have the balls to do so lol
I would love to have one of those
(filled ofcourse)
mercury is the coolest material ever (in my eyes)
Do you have a video on where you made the vacuum controller?
There will be a video in the future. I redesigned the PCB. As soon as I get it manufactured I will start working on the video. But it have a video about my old gauge controller.
Hey Advanced Tinkering, I recently found your channel and I am amazed about your content. I enjoy the high quality and depth of your videos. As a chemist I was wondering that it is always claimed that the alkali metals form a colored vapor upon distillation, however looking at the videos on yt distilling them under vacuum it is never visible. Could you perhaps perform an ambient pressure distillation of small amounts Na or K in an inert atmosphere to check if the reported claims are valid ? Just an idea, also use a cheap setup of course, just short path under argon or similar. Best Max
Hi Max!
Thanks! That's a very interesting idea. I'll have to see if and how I can realize that. Since alkali metals have a boiling point above the softening temperature of borosilicate glass at normal pressure, I'll likely need to use quartz glass. And working with that is difficult to nearly impossible with my burner.
@@AdvancedTinkering Yes you are right, I didn't have the boiling points memorized and looking them up they are indeed quite high. Maybe a long narrow fused silica "testtube" under a stream of argon might suffice. So that the vapor gets condensed along the temperature gradient but is still under argon. However at these temperatures maybe the alkali metal will just react with the fused silica. Anyways was just an idea. Looking forward to your next vid.
I suspect these pumps are usually run for a long period. Are the losses of mercury considerable with this system? Do you need to empty the traps from time to time?
They can run a very long time, you can get any mercury that escapes with a cold trap and recover it.
This is really cool, however since I'm not experienced with what a "standard vacuum" is - it's hard to understand how extreme 7e-5 mbar is. Is it a really strong vacuum or is this more about the concept itself?
That is approximately the vacuum found in interstellar space.
@@christopherleubner6633wut? not even close. Interstellar space is TWELVE ORDERS OF MAGNITUDE lower pressure than what this pump achieved. The pump pressure isn't even the equivalent of being IN space, it's going to be roughly the same as being a couple km below the Karman line at 100km.
Careful not to accidentally electrocute yourself using it like Cody and his Sprengel pump! haha
Amazing job well done how are you doing
Cool toys
Thanks! I'm doing fine! :)
@@AdvancedTinkering cool
A link to the oil diffusion pump video mentioned at 0:26 - th-cam.com/video/dNOFNq-4F9A/w-d-xo.htmlsi=Jt-6fr8zEhu8Yyn4&t=1
It would take ages but would be hilarious to use a Sprengel pump for roughing.
Great demonstration. I've only read about them.
Thanks!
True, that would be very neat.
Can this be used with gallium?
(Assuming one is using the proper diameter tubes, connectors, etc.)
I don't think so. Even in a vacuum, the boiling point of gallium is way to high.
what flow at 7:10 ? the Merkelar Flow ? can anybody plz explain I understand the meaning but I don't know the term. Or can't understand him properly.
Sorry for my unclear pronunciation. The term is "molecular flow".
@@AdvancedTinkering OK, thanks, that makes sense now. Thanks for the clarification.
All I want to know is where did you get that much mercury lol
Supermarket ;)
so why would you choose complex vs simple, I dont get it, I mean just use these evaporation condensation vacuums, I think this model is overcomplicated tho, can be single simple step vacuum by condensation of vapour. the more simple diy at home super vacuum is when the vapour is the operating environment of the vacuum, condensing output is directly below the actual chamber, with a switch valve and boiler. engineers, makers, k.i.s.s., no you dont have to copy from others how they have done things, you can think yourself and choose the best system.
schad das du nur auf englisch laberst
You could combine this mercury pump with Cody's Lab gravity mercury vacuum pump then you wouldn't need a electric roughing pump🤔