Twin-array capacitance sensor for multi-parameter measurements of multiphase flow

We propose a twin-array capacitance(TAC) sensor for the measurement of concentration,velocity,and flowrate of gas-solid two-phase flow.Using the sensitivity non-uniformity of a neighboring electrode,the regional concentration of the cross-section was reconstructed directly.Additionally,the finite element method was used to analyze the capacitance of the sensors composed of a different number of electrodes.TAC sensors with 4,6,and 8 electrodes were found to be the best for regional concentration measurements.Based on this,the 8-electrode twin-plane electrical capacitance tomography(ECT) sensor,the 4-electrode TAC sensor,and the 6-electrode TAC sensor were used to measure the concentration,velocity,and flowrate of granules in granular flow.The flowrates measured by ECT and TAC were compared with the flowrate obtained by a gravity sensor to verify the measurement accuracy.Experiments on vertical and inclined pipelines with granular flow were carried out.We found that the flowrate accuracy of the 4-electrode TAC is distinctly better than that of the 6-electrode TAC in the vertical pipeline while the flowrate accuracy of the 4-electrode TAC and the 6-electrode TAC were similar for the inclined pipeline.