Question

Why is wet steam converted into superheated steam after throttling

Answer 1

⭕The throttling calorimeter makes use of the fact that the enthalpy before throttling is the same as that after throttling, in order to determine the dryness fraction, x, of the steam passing through the calorimeter. The wet steam passes through a small orifice where it must undergo a sufficiently large pressure drop to become superheated.

⭕ In other words it is allowed to expand sufficiently so that all of the liquid part becomes vapour.