Fig.12: Path lines from powder particles with inlet pressure At 1000 Pa

The simulation result of the prototype nozzle

 indicated that increased transfer efficiency is

 achieved when the inlet pressure is set at

 1000Pa with more than 90% of sprayed charged

 powder particles deposited on the target surface.

6.0 Conclusions

In this paper, a methodology for increasing powder deposition efficiency in corona applications has been presented. The methodology demonstrated an approach to nozzle design with a view of reducing over spray. A computational fluid dynamic code, Fluent, was used to simulate inlet pressure into gun nozzle from the venturi pipe. The CFD simulation offered an opportunity to investigate wide range of nozzle parameters with a view of finding an optimal candidate nozzle design for the powder application process. Experimental results of the candidate gun-nozzle indicated that powder deposition efficiency improved significantly.