Method for the determination of the ignition temperature of oil spray

Special equipment was constructed to investigate the ignition of oil spray. The oil was atomized by compressed air into a rectangular chamber. A screen (0.75 × 0.75 m) was fixed half way along the chamber, perpendicular to the spray. A hole (6 mm diameter) in the screen made it possible to isolate part of the spray. The spray was ignited by a standard gas flame placed behind the screen. The lowest temperature of the oil causing ignition was assumed to be the ignition temperature of the spray. The experimental set-up facilitated the investigation of the influence of the initial temperature of the atomizing air and the ratio of air to oil on the ignition temperature of the spray. It was shown that the ignition temperature of the spray is less than the flash point by 44-50 K. An increase in the initial temperature of the air decreased the ignition temperature of the spray. This dependence was rectilinear. It was found that the ignition temperature of the spray reached its minimum at a ratio of air to oil of ~ 0.8 for all the oils tested.