METHOD AND APPARATUS FOR EJECTION OF PARTICULATE MATERIAL

摘要

The invention concerns an apparatus for generation and ejection into air of discrete agglomerations of a particulate material with a proportion of liquid from a liquid having the particulate material therein. The apparatus defines an ejection location (128) and an electrical potential is applied to the ejection location to form an electric field at the location, and liquid (122) with the particulate material is supplied to the ejection location. An oscillating voltage (A) is applied to the ejection location, the magnitude of the voltage being below that required to cause ejection of particles from the ejection location, and an ejection voltage (B) is superimposed on the oscillating voltage additively with the oscillating voltage in order to cause the sum of the voltages at the ejection location to exceed the threshold required for ejection, when required.