A high resolution electrostatic probe has been designed and constructed. This laboratory system is capable of detecting charge on individual particles I it has been demonstrated to work and is able to detect bipolar charging. In the cohesion and adhesion of powders electrostatic forces play a significant role. This system therefore can be used to predict such properties of powders.
The probe has been used to measure charge on PVC particles of diameter down to 50um. The powder was processed by several different methods and the charge generated on the particles measured. Bothmonppolar and bipolar charging was observed.
Further developments on the system are necessary -before it can be used in industrial systems to evaluate powder flow . properties. The following work will enable a comprehensive instrument to be constructed:
1. Improvements on the existing system such as increase in spatial resolution, incorporation of a micro- processor to analyse data and motorise movements of an array of probes.
2. Application of probe in a laboratory powder flow system.
3. Tests on a full scale pneumatic conveying system.
The final instrument will utilise electrostatic charging phenomena that is inevitably present in almost all powder handling processes to measure such flow parameters as velocity, cohesion, particle size distribution etc.