Investigations on lean coal combustion for different primary air velocities in a lateral-ignition tiny-oil burner

An experimental study was conducted to show the influence of the primary air velocity on lean coal combustion in a lateral-ignition tiny-oil burner. Using the lateral ignition scheme, a lean-coal ignition experiment was conducted at a coal feed rate of 3.5 t/h and primary air velocities of 15, 20, 25, and 30 m/s. During firing up with three oil guns in the presence of coal, the gas temperature along the center line increased along the flow of primary air. The gas temperatures on the side of the oil guns (r=+116.5 mm) were higher than those on the opposite side (r=-116.5 mm). As the primary air velocity increased, the gas temperature along the center line at the same measurement point decreased while that on the side with the oil guns rose. However, the gas temperature on the opposite side changed only a little. O2 concentrations at the exit of the burner were 1-3%. The burner resistance resulting from the flow and combustion of pulverized coal was 1,300-1,800 Pa.