Measurement of two-phase mixture level using an ultrasonic method

An ultrasonic method is developed for the measurement of a two-phase mixture level. The proposed approach can be used as a level measurement method in a reactor vessel or steam generator. A commercial ultrasonic method is used and modified for application under conditions such as high temperature and pressure, as well as severe surface fluctuation. The modifications are as follows: (1) The calculation method of the ultrasonic velocity is modified such that it can be predicted correctly under high temperature and pressure conditions considering the medium as a homogeneous mixture of air and steam; and (2) a waveguide is developed to reduce the loss of echo by the effects of attenuation and by the diffused reflection from the fluctuated surface of the water level. Finally, the developed method is verified under high temperature (211 °C) and pressure (1.95 MPa) conditions. It is concluded that the developed ultrasonic method measures the two-phase mixture level more accurately than the conventional methods at high temperature and pressure conditions as well as under conditions of surface fluctuation.