Flame characteristics of a non-premixed oxy-fuel jet in a lab-scale furnace

The effect of varying the fuel and oxidizer composition on flame characteristics in a non-premixed oxy-methane flame was experimentally investigated in a lab-scale furnace with a slot-type burner. The fuel composition was varied in the range of XF,CH4 = 70∼100%, XF,H2 = 0∼15%, XF,CO = 0∼10%, and XF,CO2 = 0∼30% while the oxidizer composition was changed in the range of XOx,O2 = 70∼100 and XOx,CO2 = 0∼30%. Flow velocity at the nozzle exit was fixed at uF = 25 m/s for the fuel jet and uOx = 25 m/s for the oxidizer. The objective of the current study was to investigate the effect of varying the fuel and oxidizer composition on flame stabilization, flame luminescence, flame slope, liftoff height, flame length, and furnace inside temperature in a non-premixed oxy-fuel flame. The addition of H2 and CO (carbon monoxide) to a fuel jet had the positive effect of broadening the flammable limit. The hydroxide radical chemiluminescence (OH*) intensity was related to adiabatic temperature. The flame slope was affected by global equivalence ratio and the mass flow rate between the fuel and the oxidizer. The liftoff height decreased with the increase in edge flame velocity while the flame length decreased with the increase in the Péclet number of unburned gas.