A charge injection nozzle for atomisation of fuel oils in combustion applications

A charge injection nozzle suitable for package burner applications has been designed and tested, spraying insulating liquids such as kerosene, diesel or white spirit. The nozzle consists of a sharp pointed needle as a charge injector and a shaped nozzle body as an anode and extractor. A systematic experimental study together with numerical modelling has been carried out to optimise the nozzle and establish the basis for the theoretical study. The design of the nozzle is based on a better understanding of the charge injection mechanism within the liquid. A detailed method of space charge modelling is given in optimising the geometry of the nozzle. Results showed that the internal shape of the nozzle body plays a vital role for controlling the charge injection rate and atomisation efficiency. Size measurement results confirm that electrostatic disruptive forces can give greatly enhanced atomisation efficiency for hydrocarbons at flowrates required in practical combustion systems