Vacuum insulated evaporator

A vacuum insulated evaporator (VIE) is a form of pressure vessel that allows the bulk storage of cryogenic liquids including oxygen, nitrogen and argon for industrial processes and medical applications.

[1] The purpose of the vacuum insulation is to prevent heat transfer between the inner shell, which holds the liquid, and surrounding atmosphere.

[2] Without functioning insulation, the stored liquid will rapidly warm and undergo a phase transition to gas, increasing significantly in volume and potentially causing a catastrophic failure to the vessel due to an increase in pressure.

To combat such an event, VIEs are installed with a pressure safety valve.

To remain a liquid, the vessel contents must be kept at or below its critical temperature.