Numerical Simulation of Gas-Solid Flow in Blowpipe of Blast Furnae with Pulverized Coal Injection

摘要

A mathematical model basede on the finite-difference solution of momentum, enthalpy, and species conservation equations has been constructed to describe the gas-particle flow in blowpipe of blast urnace. Coal particles are simulated as a continue phase. Predictions give the detailed information of two-phase flow and mixing, including gas velocity, particle velocity, oxygen and particle concentration distributions at each location inside the blowpipe. It is shown that the oxygen concentration around the particles of coal can be improved by the use of an oxygen-coal lance, thereby both of the utilization efficiency of oxygen and the coal combustion rate can be improved. The oxygen-coal lance has little effect on the main flow in blowpipe. Actions of oxygen jet rotation can improve the blending of oxygen and pulverized coal, but the effects of jet from oxygen-coal lance is much weaker than that of the blast flow in blowpipe. The mass and momentum transfers near the exit of lance are very strong.