Velocity Measurement of Pneumatically Conveyed Particles through Digital Imaging

A digital imaging based method for measuring the velocity of pneumatically conveyed particles is described in this paper. The measurement system consists of a laser sheet for illumination, a CCD camera for particle image acquisition and bespoke image processing software. By controlling the exposure time of the camera, blurred images of moving particles are captured, which contain velocity information of the particles. The relationship between the motion blur length and the particle velocity is established using a lens model of the camera. To improve the robustness of the system to noise in the acquired particle images, a traveling wave equation (TWE) method is used to estimate the motion blur length and then deduce the particle velocity. In addition to computer simulations, experimental work on a a free fall particle flow rig and pneumatically conveying test rig is carried out. The results indicate that the proposed method is feasible for the velocity measurement of pneumatically conveyed particles.