An Integrated Instrumentation System for Velocity, Concentration and Mass Flow Rate Measurement of Solid Particles Based on Electrostatic and Capacitance Sensors

Abstract

The online and continuous measurement of velocity, concentration and mass flow rate of pneumatically conveyed solid particles for the high-efficiency utilization of energy and raw materials has become increasingly significant. In this paper, an integrated instrumentation system for the velocity, concentration and mass flow rate measurement of dense phase pneumatically conveyed solid particles based on electrostatic and capacitance sensorsis developed. The electrostatic sensors are used for particle mean velocity measurement in combination with the cross-correlation technique, while the capacitance sensor with helical surface-plate electrodes, which has relatively homogeneous sensitivity distribution, is employed for the measurement of particle concentration and its capacitance is measured by an electrostatic-immune AC-based circuit. The solid mass flow rate can be further calculated from the measured velocity and concentration. The developed instrumentation system for velocity and concentration measurement is verified and calibrated on a pulley rig and through static experiments, respectively. Finally the system is evaluated with glass beads on a gravity-fed rig. The experimental results demonstrate that the system is capable of the accurate solid mass flow rate measurement, and the relative error is within −3%–8% for glass bead mass flow rates ranging from 0.13 kg/s to 0.9 kg/s.

Development of ring-shaped electrostatic coupled capacitance sensor for the parameter measurement of gas-solid flow

“…Electrostatic sensors and electric tomography were combined to investigate the hydrodynamics of a triple-bed combined circulating fluidized bed (Zhang et al, 2013), where the particle concentration distribution and velocity are simultaneously measured and compared over a wide range of flow regimes, including the dense plug flow regime, the core-annular flow regime, and the dilute suspension flow regime. Besides, two ring-shaped electrostatic sensors for particle velocity measurement and a helical capacitance sensor for particle concentration measurement were integrated to develop an instrumentation system, which was used for the online measurement of the velocity, concentration and mass flow rate of the dense phase pneumatically conveyed coal particles on a pilot gasifier (Li et al, 2015b; Li et al, 2018). However, in these works, the electrostatic and capacitance sensors are sequentially arranged along the flow direction and thus they cannot achieve the simultaneous measurement of the particle velocity, concentration and flowrate within the same sensing space in gas-solid systems.…”

Ultrasound Pulse-Echo Coupled with a Tracking Technique for Simultaneous Measurement of Multiple Bubbles

“…The cross-correlation is commonly applied to detect the delay of a signal with a known or assumed waveform [ 4 , 5 , 6 , 26 , 27 , 28 , 29 , 30 ]. A common error of the cross-correlation is the detection of a secondary maximum instead of the real one [ 26 ].…”

Intelligent Measuring of the Volume Fraction Considering Temperature Changes and Independent Pressure Variations for a Two-Phase Homogeneous Fluid Using an 8-Electrode Sensor and an ANN

“…In a study conducted by Li and colleagues [ 16 ], they explored the error-measuring matter in capacitance-based sensors and identified that the incorporation of homogeneous sensibility can effectively decrease such errors. Subsequent endeavors were undertaken to augment and establish a framework that ensures uniform sensitivity, wherein it was ascertained that the helical electrode is the most efficacious means of attaining said objective [ 17 , 18 , 19 ].…”