The effect of high swirl on reducing emissions from liquid fuel burner system

Abstract

Combustion implicates harmful effect to the environment because of the emissions produced. The release of gaseous emissions such as oxides of nitrogen (NOX), and carbon monoxide (CO) into the atmosphere creates major environmental problems. These gaseous emissions affect plants, human being and animals. High concentration of emissions brings fatal effects to life form. A liquid fuel burner system with different high swirl radial air swirler vane angles with 280 mm inside diameter combustor of 1000 mm length has been investigated. All tests were conducted using commercial diesel as fuel. A radial flow air swirler with curved blades having 50 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 single fuel nozzle pointing axially outwards. The swirler vane angles and equivalence ratios were varied. Tests were carried out using four different air swirlers having 45°, 50°, 60° and 70° vane angles. NOX reduction of more than 11 percent was obtained for the swirl number of 1.427 compared to 0.780. A turning point occurs at this stage where the emission of NOX suddenly increases about 13 percent when swirl number of 1.911. CO emissions were reduced by 12 percent, 21 percent and 32 percent for swirl number of 0.978, 1.427 and 1.911 compared to swirl number of 0.780 respectively.