Measurement of particle flow by optical spatial filtering

This paper describes a new method to measure the flow of particles being conveyed pneumatically in a pipe. The proposed method determines the flow from the particle speed and also the mass concentration. The method requires only a light emitting source and light sensors on either side of a pipe. The particle speed is measured by the spatial filter. The particle concentration measurement employs the intensity of the light incident at the light sensor. The mass concentration of particles and the intensity of transmitted light can be linked by Lambert-Beer´s law. Experiments were carried out to validate the method