Application of travelling wave field technique for handling cohesive powders

The main objective of this research is to study the transport phenomena of cohesive powders using travelling wave field technique. This technique has been successfully utilised for transporting and separating noncohesive materials in many applications. In the literature only a limited attention has been paid to the transport of cohesive powder materials using this technique. Cohesive powders are generally much more difficult to transport due to short range molecular forces as well as electrostatic forces. Such forces usually cause agglomeration of particles which may significantly impede the flow. In this study, an optimisation process for selecting appropriate electrodes arrangement for levitation and transportation of a given powder is presented. Computer modelling was used to establish how the shape and geometry of the electrodes influence the transport of the particle for a given size and charge to mass ratio. Based on the modelling results a flat-bed arrangement was constructed and used in the experimental study. Cohesive lactose 150 Mesh powder was successfully dispersed and transported using this panel arrangement. Particle trajectories were examined using a CCD camera with telemicroscopic lenses interfaced with a computer controlled image grabbing system.