Local solid particle velocity measurement based on spatial filter effect of differential capacitance sensor array

Abstract

This study proposes a novel velocity measurement method based on a differential capacitance sensor array (DCSA) for the solid particles in gas-solid flow. Firstly, the DCSA is modelled by the finite-element software ANSOFT, and its sensitivity characteristic is acquired. Additionally, the spatial filtering effect of DCSA is theoretically investigated, which validates the feasibility of particle velocity measurement based on DCSA. By measuring the frequency bandwidth (cut-off frequency) of the DCSA's output capacitance signal, the velocity of the local particles in the pipeline can be calculated. Further through the form of differential detection, the cut-off frequency can be accurately converged. Finally, a novel solid particle velocimeter based on DCSA is developed and tested on a gravity-delivery particle experimental device. The results indicate that the method has the feasibility for the velocity measurement and its repeatability is within 11% over the velocity range of 1–3 m/s.

Keywords

• finite element analysis
• capacitive sensors
• velocimeters
• velocity measurement
• spatial filters
• sensor arrays
• computerised instrumentation
• capacitance measurement
• differential detection
• gravity-delivery particle experimental device
• differential capacitance sensor array
• gas-solid flow
• finite-element software ansoft
• spatial filtering effect
• local solid particle velocity measurement method
• solid particle velocimeter
• dcsa output capacitance signal
• velocity 1.0 m/s to 3.0 m/s