No abstract

Measurements inside a flame tube are presented and compared for a range of confined liquid fuel oil, gaseous fuel and dual fuel flames. The operating conditions include a range of three heat inputs 29 kW, 38 kW and 48 kW. For dual fuel flames three gaseous fuel ratios 25 %, 50 % and 75 % are considered. The experimental work takes place using an industrial type, dual fuel burner that is especially designed and constructed to utilize the three types of firing. This burner is fitted to a water cooled cylindrical furnace (the Combustor). [t is found that. Burning gaseous fuel simultaneously with liquid fuel oil, acts as a hot shield surrounding the oil spray flame. This shield serves to reduce significantly the loss of combustibles from oil flames, mainly through enhancing the evaporation process of fuel oil droplets and increasing soot burnout at the flame region as well as preventing the surviving soot particles from being deposited on furnace walls. The importance of these conclusions emerges when burning low grade fuels or bituminous fuels which needs a more carefully designed combustion system.