Influence of Gas Diluents on the Temperature of a Laminar Coflowing Jet Diffusion Flame in a Honeycomb Gaseous Burner

Abstract

A series of experiments were performed on a flat honeycomb burner with air coflow to ensure laminar flow in order to study the effect of Acetylene/Argon mixture to the natural gas (NG) on the temperature distribution and flame structure. The burner assembly could be traversed in the horizontal and vertical direction controlled by using a field point system to scan the flame radially and axially. The flow rate of fuel, diluents and air was measured using differential pressure flow meters. The whole supply lines were calibrated. Methane gas, air and Acetylene/Argon mixture were injected through mixing pipes controlled with solenoid valves handled with a LabVIEW program. The combustion flame was in room atmospheric conditions with room disturbances controlled to treat such flames as free jet diffusion flames. The laminar flame axial and radial temperature profile was measured using a shielded-aspirated platinum/ Platinum-13% Rhodium thermocouple (type R). Flame images were taken using Canon EOS camera with CMOS sensor, up to 3.7 fps. The fuel used was NG with flow rate from 180 up to 520 ml/min. Ar flow rate up to 350 ml/min and C2H2 up to 100 ml/min with a constant coflow air of 3 l/min. The choice of the different Investigated cases was based on flame stability. The results obtained indicate the following: – In case of using air, NG and Ar, the fuel rich zone tends to vanish and in case of injecting Ar and acetylene mixture in addition of NG and air the front zone tends to vanish and the flame became mainly diffusion. – Maximum temperature was at the flame tip in all cases. Increasing Ar percentage up to 50% decreases tip temperature to nearly 870°C compared to the typical case (about 1000 °C); increasing acetylene content over 15% resulted in dense soot formation.