Huge-scale capacitance mass flowmeter in gas/solid two-phase flow with rectangular vertical pipeline

Abstract

A huge-scale capacitance mass flowmeter in gas/solid two-phase flow is proposed to measure the mass flowrate of rectangular vertical pipeline. The dimension of the sensor section is 2 m in length and 0.5 m in width. Two planes of capacitance electrodes are arranged in the flow direction, and the flow velocity of particle can be obtained by correlating the particle concentration of the two planes. Therefore, the mass flowrate of the particles can be calculated from concentration and velocity of the particles. Simulation and experiment are combined to optimize the sensitivity distribution of the sensor section, so that the fringe effect in the lateral and axial direction can be eliminated. The problem of ground capacitance and temperature drift in the huge-scale sensor are solved. The ac-based capacitance measuring circuit is improved and its performance is tested using this experiment. A gravity experimental setup with a height of 7 m is built to test the performance of the designed capacitance flowmeter. The experimental result has shown that the results from the measuring system are repeatable and therepeatabilityerror is 1.365%. The measurement errors in the mass flowrates of 7.5 kg/s, 16 kg/s, 23.5 kg/s and 33 kg/s are 29.3%, 8.3%, 4.1% and 3.5%, respectively. The results indicate that the measurement system has a satisfying level of measuring accuracy when the flowrate is above 16 kg/s. This measuring method provides a valuable reference for huge scale application.