Optimized Design On Capacitance Sensor For Concentration Measurement Of Pulverized Coal

Owning to the advantages over many other measurement techniques, such as high sensitivity, fast in response and non-invasive, a capacitance sensor is always used in pulverized coal concentration measurement. But a capacitance's sensitivity over the pipe cross section is not high and homogeneous, also the value of capacitance made by the change of pulverized coal concentration is very little and the measurement result is affected by the flow regimes. So, it is needed to get a reasonable capacitance structure that has a high applicability and precision by optimized designing. In this paper, based on the rules of the electrostatic field, we analyze some primary factors that affect precision and design the structure of capacitance sensor that has a high homogeneous distribution of sensitivity of the sensing field in the electrostatic field by optimized designing. The new designed capacitance sensor can measure pulverized coal concentration in complex flow regimes, such as core flow, annular flow and stratified flow effectively. We make experiments in the laboratory to study the sensor and test the right of the theories calculation. The work lays foundation for industrial application.