Combustion characteristics in oil-vaporizing sustained by radiant heat reflux enhanced with higher porous ceramics☆ ☆

Liquid vaporizing combustion in porous ceramic burner has fine flame stability and characteristic of low emission. On the other hand, vaporization control has been seldom mentioned. In this work, kerosene vaporizing type combustor equipped with a porous ceramic plate, which has the porosity of 85%, is developed in order to enhance a rate of vaporization of the liquid fuel. The stability of combustion and NOx emission characteristics were investigated in fuel vaporizing ceramic combustion. The plate burner is made of Al2O3 ceramic which has an optical-thickness of 0.54. The optically thin ceramics improved flame stability and enhances more fuel vaporization rate than optically thick ceramics. The thermal radiation energy from flame and the furnace walls can penetrate easily through the large pore of the ceramic plate. It is found possible to dispense the electric power for the fuel vaporization and the stable combustion is self-sustained by enhancement of vaporization, where the reflux rate of radiant heat was no less than 2% of the heating value.