On-line measurement of particle size distribution using piezoelectric sensors

In many industrial processes involving gas/solid two-phase flows it is desirable to measure various parameters relating to the solid particles. Particle size is one of the most important features relating to process efficiency, pollutant emissions and product quality. In this paper, a novel instrumentation system is proposed to achieve on-line continuous measurement of particle size distribution based on a polyvinylidene difluoride (PVDF) piezoelectric film sensor. The sensor is attached to an impact bar intruding into solid particle flow. The impact events, between the impact bar and the particles, generate a sensor output signal. The relationship between the sensor output and the particle size is modeled mathematically, which can be used to infer the size distribution. Experimental work is undertaken to evaluate the effectiveness of the on-line particle sizing system and the validity of the mathematical model.