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 .

A Model-Based Analysis of Capacitive Flow Metering for Pneumatic Conveying Systems: A Comparison between Calibration-Based and Tomographic Approaches

“…Information about the particle velocity can be obtained from the time series of the measurement signals. Hereby, frequency analysis of the capacitive signals from dedicated electrode structures [ 13 , 14 ] or correlation analyses of signals from multiple sensors are applied [ 15 ]. The calibration-based approach is often limited to a subset of possible flow regimes.…”