Electrostatic introduction theory based spatial filtering method for solid particle velocity measurement

Electrostatic induction theory based spatial filtering method for particle velocity measurement has the advantages of the simplicity of measurement system and of the convenience of data processing. In this paper, the relationship between solid particle velocity and the power spectrum of the output signal of the electrostatic senor was derived theoretically. And the effects of the length of the electrode, the thickness of the dielectric pipe and its length on the spatial filtering characteristics of the electrostatic sensor were investigated numerically using fnite element method. Additionally, as for the roughness and the difficult determination of the peak frequency integral(max) of the power spectrum characteristics curve of the output signal, a wavelet analysis based filtering method was adopted to smooth the curve, which can determine peak frequency integral(max), accurately. Finally, the velocity measurement method was applied in a dense phase pneumatic conveying system under high pressure, and the experimental results show that the system repeatability is within +/- 4% over the gas superficial velocity range of 8.63-18.62 m/s for particle concentration range 0.067-0.130 m(3)/m(3).