Electrical Phenomena in Particulate Systems

Work on this line originates from the development of the Electromechanical Valve for Solids (EVS), which is a novel device for flow control of granular materials using electrical effects. The development has now stimulated research on the electromechanics of particulate systems.

In a further recent development, the electrical clamping phenomenon is used to promote coalescence of the water droplets and to enhance their separation from a continuous oil phase.

Spraying and prilling of extremely viscous liquids and suspensions produce very large droplets which may be unsuitable for further processing. Here again the electrostatic phenomenon is used to reduce and control the droplet size.

Finally, tribo-electrification of powders is of interest as it causes segregation, flow problems and explosion hazard. We have developed three instruments for tribo-electric charging and its measurement using a Faraday cage: single particle impact tester, a shaking method and most recently aerodynamic dispersion using the dispersion unit of Malvern Panalaytical Morphologi G3.

• De-watering of Water-in-Oil Emulsions by Electrocoalescence and Development of Compact Electrocoalescers
• Characterisation of Electrostatic Charge in Dispersed Powders

• Characterisation of the tribo-electric properties of pharmaceutical powders
• Tribo-electrification and Associated Segregation of Formulated Bulk Powders
• Tribo-electrification of pharmaceutical powders
• Flow and Electrical Behaviour of Powders in the Electromechanical Valve For Solids
• Electrostatically-Assisted Production of Viscous Drops
• Electrostatic Enhancement of Coalescence of Water Droplets in Oil