Talk:Liquefaction of gases

liquefaction inside turboexpander
could you please explain how the following two statements - the first from the article - can coexist?:

"While expanding, the gas has to do work as it is led through an expansion turbine. The gas is not yet liquid, since that would destroy the turbine."

"In most instances, the inlet gas to the expander is very cold and at or near saturation. This means that the gas passing through the expander will not only get colder, but some of the heavier compo- nents will also liquefy. Usually, this liquid contains valuable product that is recovered as a result of the condensation process, making the plant more efficient. The amount of this liquid can vary from about zero to 50 percent of the inlet stream (weight percent- age basis), depending on the process conditions." source and further reading: Jumonville, Jigger:TUTORIAL ON CRYOGENIC TURBOEXPANDERS, in: PROCEEDINGS OF THE THIRTY-THIRD TURBOMACHINERY SYMPOSIUM, 2004, p. 128, https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/163246/t33-15.pdf%3Fsequence%3D1%26isAllowed%3Dy&ved=2ahUKEwj3lN6Lwu39AhWIH-wKHTiODZ0QFnoECAsQAQ&usg=AOvVaw2jtq_xxGK6XW6QUq_V8j-M

if there is a contradiction please correct the article. thanx!

one also asks oneself what the sense of "The gas is not yet liquid" could be? if it were liquid already it would not have to be liquefied... so is what's meant here a mixture of gas and liquid? then the formulation should be: "in the inlet-stream there is not yet any liquid component, ..."

I would add: "However liquid droplets may form inside the expander, up to 50 % of the inlet stream."

if I understand well this enhances enormously the efficiency of the process because the phase change energy must appear at the shaft of the expander (while already liquefying a part of the medium), or not?

HilmarHansWerner (talk) 17:40, 21 March 2023 (UTC)