Particle velocity measurement method of dense-phase gas–solid flow based on an electrostatic sensor array

Particle velocity is an important parameter of dense-phase gas–solid flow for both monitoring and control purposes. This paper presents a recent development in the noncontact measurement of solid particle velocity using an electrostatic sensor array (ESA). The electrostatic sensor array with eight electrodes is used to collect electrostatic signals generated by the moving charged particles. A velocity measurement method based on the tomography technique is presented, which measures the velocity of solid particles in the horizontal pipeline. The simulated model of the ESA with eight electrodes is built, and the sensing area of the ESA is mapped onto 13 pixels of equal area. Simulation tests are then conducted to evaluate the feasibility and accuracy of the velocity measurement at different positions. Finally, experimental tests are conducted on the horizontal conveying pipeline of a high- pressure dense-phase pneumatic conveying pilot system. Results indicate that the proposed method is capable of measuring the spatial average velocity of pulverized coal over the cross-sectional area of pipe with a relative error within  ±7% for the conditions of particles tending to be of uniform distribution. In addition, the effect of moisture on velocity measurement is investigated. (paper)