Local particles velocity measurement using differential linear capacitance matrix

Abstract

A novel differential linear capacitance matrix (DLCM) was designed for measuring the velocity of the local particles within pneumatic conveying pipeline. The 3D simulation model of the DLCM was built and its sensitivity distribution was analyzed by the finite element method. The velocity measurement principle of the DLCM based on its spatial filtering effect was theoretically deduced, and the velocity of the local particles within the pipeline can be obtained by determining the narrow-band peak frequency of the output capacitance signal of the DLCM. Then the DLCM-based particle velocimeter was further developed and its performance was verified on a gravity-fed solids flow rig. Simulation and experimental results demonstrate that the measurement method is capable of measuring local particles velocity robustly with a relative error not greater than 5.5% and a repeatability less than ±7.78% over the velocity range of 2.4–5.8 m s−1.