Simulation of Transport Phenomena around Raceway Zone in the Lower Part of Blast Furnace

Abstract

A two dimensional mathematical model was developed to describe transport phenomena in a packed bed of coke in front of blast furnace tuyere including pulverized coal combustion. The model consists of two submodels, one is pulverized coal combustion model in a blow pipe and the other is combustion model in packed bed of coke. In this model coke particles in a raceway are treated as a kind of fluid and flow patterns of gas and solid phase are calculated by using two phase flow approach. This model was applied to practical operation conditions. When pulverized coal injected into tuyere, more oxygen is consumed and higher temperature rise appears at the region more close to tuyere tip in the raceway and lower temperature is represented in the coke bed than those of all coke operation. Residence time of pulverized coal particles in a blow pipe is quite short, so burning rates in a blow pipe are very low and the pulverized coal particles mainly burn in raceway cavity. The burning rate of pulverized coal particle increases with volatile matter content of original coal, but some particles reach to inner wall of tuyere when high volatile coal is used.