Measurements of the Flowrate f a Steam-Liquid Mixture by Standard Orifices

An equation for the mass flowrate of a steam-liquid mixture as a function of the measured pressure drop across an orifice plate is obtained. It is shown that the main problem in the calculation is to determine the liquid holdup and the steam void fraction at the contracted cross section downstream of the orifice plate. Different assumptions on the mechanism of mixture flow through the orifice plate are examined. A practical method for calculating the mixture flowrate is proposed.