Analysis of effervescent spray quality for oil-fired furnace application

The quality of liquid fuel atomization is a key factor in the formation of gaseous pollutants and particulate emissions. This paper investigates the quality of effervescent spray, which has established itself as a promising alternative to conventional spray formation mechanisms. The reported results were obtained using a dual-phase Doppler analyser. Droplet data were collected in multiple locations varying both axially and radially, in intermediate spray region. The results display spatial development of Sauter mean diameter (SMD) in effervescent sprays at different operating conditions, but they also show that SMD may be insufficient to characterize the spray, especially near to the dense spray region. This conclusion is based on the observed large variance of drop size and velocity and on their mutual correlation. It is concluded that for modelling purposes, joint distributions of drop size and velocity would be more appropriate to fully characterize the primary atomization in an effervescent spray.