Giant glass diffusion pump and cathode ray tube demo

This vacuum diffusion pump is made entirely of glass so we can see how it works. I also show a CRT built from a glass lab flask.

The tabletop burner and fuel are commonly found at Asian supermarkets.

[theCodyReeder]

A glass pump with mercury would sure look cool though.

[ronboe]

When I was in college one of my profs was telling stories about his vacuum experiences. One; he had carefully set the system up, using all the lessons learned earlier (e.g. new copper gaskets) but it would not pump down. Tore the rig apart and found a fly in one of the tubes. Turns out flies out gas rather well. :^)

[TumbleFig]

Applied Science: Oh yeah, and I made a CRT out of some things I had lying around, NBD.

[AsymptoteInverse]

While it might not be the most practical diffusion pump ever, that pump is still a thing of beauty.

[dennismckee]

I've worked with the large diffusion pump system for years and understood the theory, but THIS is what I've always wanted to see. Thank you this is awesome.

[andymouse]

Used Diff pumps a lot, no how they work, seen a hundred diagrams and only your channel showed me one running....cheers!

[jjeherrera]

As you explained in the video, the silicon oil absorbs unwanted substances, so the mechanical pump is always needed to bring the vacuum down, draining out such substances, as you did, and then getting out the residual gas. It also helps to drain down the oil vapour. If you turned the mechanical pump off, you'd contaminate your vacuum chamber, even if you cool the top of the diffusion pump with liquid nitrogen. Therefore you must have an automatic valve to shut out the connection with the chamber if electricity goes out. Actually they are a pain in the neck to use, so people prefer turbo-pumps which are far cleaner, if they can afford them, that is.
By the way, great video! I really appreciate your resourcefulness.

[raananbodzin]

Hello. I am a SEM operator. I was just studying up on SEM theory, particularly the pumping systems, turbomolecular pumps and oil diffusion pumps. I couldnt find a really good demo or video to see exactly the flow paths. Your video that is brand new, perfect timing, it really answered a lot of question of the actual flow paths for me. Thanks a million. I love your approach, discussed in the beginning of your behind the scenes video. I also learned most of my engineering skills on my own in life, garage, fixing and building things, not in the university. I am very grateful for you wonderful sharing. Raanan

[ClemoVernandez]

I applaud the glass maker that did this

[mikestoodley]

Hi, I worked for a company, before I retired, that made photomultipliers and they used mercury/glass diffusion pumps for many years. They also made some of the first television camera tubes and I think these were pumped down using mercury/glass diffusion pumps too. They had a glass blowing department where new glassware was made when required. Very interesting video, thanks very much.

[noahhoppis]

Glass diffusion pumps are still commonly used for neon sign work and were also in quite common use for producing one off vacuum tubes and the like. The advantage is in the ability to connect to an all glass manifold for gas back filling or to the pumped item directly with glassworking techniques rather than metal working techniques. As a side note DC-704 and other silicone based diff pump oils cause great havoc when exposed to atmosphere while hot resulting in an horrid black tar which cannot be removed except by aggressive mechanical means. The much safer (read: expensive) option is a Polyphenyl Ether based oil like Santovac-5 which contains no silicon.

[ArruVision]

I’ve been trying for a while to wrap my mind around how and why diffusion pumps work. Not quite there yet, but thank you for increasing the clarity a lot!

[Jademalo]

"Here's a cool video about my glass vaccuum pump"

"oh don't mind this homemade crt, I was just using it because this didn't work for my mass spectrometer"

[onlineplus]

I like how I can sit down after working all day with work stuff running through my head and instantly be engrossed by one of your videos, and having just enough knowledge to understand what you are very eloquently explaining. I think it has more to do with the fact that you make it very easy to follow along even if someone has no clue what a diffusion pump is.

[thetruthexperiment]

New videos from this channel work better than SSRIs at alleviating depression.

[weasel.]

1:55 You can not unsee those eyes on the vakuum
pump, once you have seen them.

[electronicsNmore]

Some serious work went into making that apparatus. Great video!

[mrhangfire]

At work we use liquid ring pumps(very clever pump IMO), dry screw pumps, roots blowers, and steam jets(venturi) to pull high vacuum for distillation processes. We use this vacuum post reaction and during distillation of various chemicals.

[davidadams]

Amazing. The amount of effort that goes into your videos is truly inspiring.

[_..-.._..-.._]

It’s amazing what percolation type stuff can do