Effect of the Structures of Injection Facilities on Combustion Characteristics in the Pulverized Coal Injection into a Blast Furnace

Concerning a large amount of pulverized coal injection into a blast furnace, the effect of the structures of injection facilities on the combustion of pulverized coal in a raceway cavity has been studied theoretically and experimentally.The mixing of pulverized coal with oxygen is important to promote the combustion of pulverized coal in the raceway cavity. The effect of the mixing of pulverized coal with oxygen on the subsequent combustion in the raceway cavity was estimated theoretically. With respect to the structure of injection parts, the effects of the spouting velocity and angle of oxygen jet on the pulverized coal combustion was estimated experimentally using the empty combustion furnace. As the results, the larger spouting velocity of oxygen jet and larger cross angle of the pulverized coal and oxygen injections were concluded to be preferable for the promotion of the combustion of pulverized coal. Furthermore, the effect of increasing pulverized coal flow rate and the steam injection on the combustion of pulverized coal was estimated.Based on above discussions, the injection burner and tuyere of the actual size was made and equipped on the commercial blast furnace for availability test. As the results, the performance of the developed pulverized coal-oxygen burner was confirmed for commercial use from the points of combustibility, durability, abilities of the operation, maintenance and security.