Results are presented on the effect of radial distribution of swirl and distribution of combustion airflow in a burner on spray flame characteristics. Direct flame photography and droplet characteristics in terms of size, velocity and number density have been obtained for different combination of swirl and combustion airflow in the double concentric swirl burner using an air-assist fuel nozzle. The burner allowed independent variation of swirl and combustion airflow in the inner and outer annulus of the burner. Maintaining either the radial distribution of swirl or airflow distribution in the burner constant and varying the other parameter have examined the flame features. Results have been obtained for a swirl combination of 30°/30°, 30 250L?50° and 50°/30° in the inner/outer annulus of the burner. The distribution of air was changed as 25/75, 50/50 and 75/25 percent in the inner/outer annulus, respectively. The results show significantly different distribution of droplet size in the resulting spray as well as the flame plume configuration. The noise levels were also very different. The results elucidate the role provided by swirl and airflow distribution in a burner to control the flame structure and combustion instability.
展开▼
