Replies

Helium can also be produced by liquefying air and separating the component gases. The production costs for this method are high, and the amount of helium contained in air is very low. Although this method is often used to produce other gases, like nitrogen and oxygen, it is rarely used to produce helium.

I think that's how they made the stuff at our physics department, in a cryostat. As loud as it was, I suppose it used a lot of electricity.

This was at a university and over 40 years ago, so things have probably changed since then.

I guess they used so much liquid Helium because they were a center of research into superconductivity; one of our professors and his grad students had developed the "BCS" theory.

They also had a very large cryo tank for liquid nitrogen, which was replenished by commercial deliveries from such vendors as Linde. This was used as the first stage coolant in their helium process, as well as by labs around the engineering campus.

About once a week, I would wheel about a 40 liter carboy (an overgrown dewar flask) a block or so Physics building loading dock where they had the cryogenics. My lab needed it for our high-vacuum pump cold traps.

We were buiding and operating various types of gas lasers and unconventional vacuum electron devices.