Experimental Study on Combustion Performance of Diffusion Jet Flames Using Developed Flame Holder

: In this study, a newly developed flame holder was investigated experimentally in the presence of two air sources applied to the combustion zone. The flame holder is a double cone holder with three fuel ports in the top cone to convey fuel to the combustion zone. Three coaxial pipes were used to transport air and fuel to the combustion zone. The outer pipe conveyed the secondary air with a velocity (𝐕 𝟏 ) of 6.34 m/s while the primary air was conveyed with the middle pipe with a velocity (𝐕 𝟐 ) of 7.1 m/s, 15.3 m/s, and 19.9 m/s. The inner pipe was used to convey fuel to the flame holder and hence to the combustion zone. The experiment was carried out using the diffusion flame principle in a still air environment at atmospheric conditions. The flame temperature, length, width, and emissions were first studied in the presence of primary air only, and then in the presence of both primary and secondary air. The results showed that the flame temperature, flame length, flame width, and emissions were all affected when secondary air was applied to the combustion zone alongside primary air.