Studies on Luminous and Non-luminous Flames with Spray Combustor : 2nd Report : Case of Swirl Combustor

Abstract

Swirl type combustor for study of spray combustion has been designed. Using this combustor luminous flame and non-luminos flame can be produced by shifting the spray nozzle position without changing the operating conditions. From the experimental studies the following results were obtained. (l) Supplying combustion air from tangential port, swirl number of S=0.99 was obtained. The circulation length was nearly equal to the combustion tube diameter. (2) Flame appearances were controlled by diffusion process of fuel spray and combustion air. If fuel spray was injected into a reverse flow in torroidal vortex, combustion process was so fast that non-luminous flame was obtained. (3) Paying attention to the primary combustion, combustion efficiency of swirl-type combustion was found better in the case of luminous flame, and it was shown combustion performances were controlled by the flow pattern and the spray directions.