Emission reduction from burner system by varying swirler blade angle

Abstract

This paper presents the effect of varying the blade angle of a small radial air swirler on reducing emissions such as oxides of nitrogen (NOx) and carbon monoxide (CO). In this research a liquid fuel burner system with four different radial air swirler blade angles has been investigated using 163 mm inside diameter combustor of 280 mm length. Tests were conducted using kerosene as fuel. A radial flow air swirler with curved blades having 40 mm outlet diameter was inserted at the inlet plane of the combustor to produce swirling flow. Fuel was injected at the back plate of the swirler outlet using central fuel injector with two fuel nozzles pointing axially outwards. The swirler blade angles and equivalence ratios were varied. Tests were carried out using four different air swirlers having 30°, 40°, 50° and 60° blade angles, respectively. A NOx reduction of more than 50 percent was achieved for blade angle of 60° compared to the 30° blade angle. CO emissions were also reduced by 72 percent for 60° blade angle compared 30° blade angle.