Simulation of Pulverized Coal Combustion in Blast Furnace Tuyere

Abstract

Coal injection is an important way to reduce the coke ratio in the blast furnace. The combustion of pulverized coal in tuyere and raceway directly affects the production efficiency of smelting. Based on the design and production data of a 2000 m³ blast furnace, a three-dimensional mathematical model of pulverized coal combustion in tuyere and raceway is established. The lower part of the blast furnace consisting of blowpipe-coal lance-tuyere-raceway and coke bed is numerically simulated to study the influence of blast rate and oxygen on pulverized coal combustion under a certain coal injection ratio and a certain coal particle size distribution. The simulation results show that the pulverized coal burnout decreases from 69.2% to 67.4% when the blast velocity is increased by 20 m s⁻¹, and the oxygen content increases from 23% to 27%, which can improve the pulverized coal burnout and increase the temperature in the raceway. A new direction is proposed to increase the pulverized coal burnout by optimizing the particle size selection and increasing the injection ratio of small particle size below 50 μm. The research provides theoretical and data support for increasing pulverized coal burnout.