Sciencemadness Discussion Board

New high vac line

BillWann - 28-1-2023 at 16:38

Getting ready to replace my old Vacuum system . The chemglass diff pump works well but I just got a much bigger Diffusion pump I will be using but I will have to redo the whole line . being a pretty good glassblower helps . I just finished the new cold trap that does not use ln2 or dry ice so Iam on the way .

[Edited on 29-1-2023 by BillWann]

20230127_164117.jpg - 7.3MBimage008 (1).jpg - 38kB

Chemetix - 28-1-2023 at 17:42

Very nice, I'm about to put together a high vac system myself. I was going to make something similar to the Arizona State University design, which looks very much like the unit you built. But I also have a Turbo molecular pump that I need a controller for. I'm in the throes of adding the turbo in the pump station design but bypassing it until I get a controller sorted.

Yes, being a proficient glassblower helps!

BillWann - 28-1-2023 at 18:10

That is the same one, its a wheeler diff pump . I have used a few turbo pumps but dont like them for chem Hi vac systems . I do have a turbo pump hooked up to one of my vac ovens and it works good .

yobbo II - 31-1-2023 at 08:39


The diffusion pump is a thing of beauty.

What size roughly are the holes (jets) that allow the oil vapour to emerge from the chimneys (underneath the dome shaped directors).
Is the size/number/area of the holes different as you go from the bottom chinney to the top?
I am currently trying to make a stainless steel diffusion pump. I have no clue as to what size to make the jets (I think that is the correct term).
Perhaps the exact size is not important as I do not understand what type of oil vapour flow conditions exist inside a diffusion pump.

You state you cold trap does not use LN2 or dry ice. What is a lam?

Yob