Particle velocity measurement using linear capacitive sensor matrix

A novel spatial filter structure based on linear capacitive sensor matrix (LCSM) was designed for measuring the velocity of the local particles within pneumatic conveying pipeline in this paper. The axial sensitivity distribution of LCSM was analyzed by finite element method. The velocity measurement principle using LCSM filtering property was theoretically deduced, then the velocity of local particles can be obtained by determining the narrow-band center frequency of the output periodic signals of the LCSM. A LCSM-based differential-type particle velocimeter was further developed for eliminating the influence of DC component of the output signal and its performance was verified on a gravity-fed solids flow rig. Experimental results show that the measurement method had a good repeatability, and the standard deviation of the measured velocity are less than 15.4% over the velocity range of 1.45–4.38 m/s.