Atomizers

Atomization is often accomplished by discharging the liquid at a high velocity into a relatively slow-moving stream of air or gas. The process of atomization produces a very high ratio of surface to mass in the liquid phase, thereby promoting rapid evaporation and high rates of combustion. The atomization of a low-viscosity liquid is most easily accomplished by passing it through a small circular hole. The influence of air or gas velocity is important because the atomization process is not completed as soon as the jet leaves the orifice. The narrow spray cone angles exhibited by plain-orifice atomizers are disadvantageous for most practical applications. The wide range of flows over which atomization quality is high is a most useful characteristic of the spill-return atomizer. In engine applications, an air shroud is usually fitted around the nozzle to provide both air assistance in atomization and air scavenging of the nozzle tip, using the pressure differential across the combustor liner wall.