Effects of Shaft Tuyere Parameters on Gas Movement Behavior and Burden Reduction in Oxygen Blast Furnace

Abstract

Parameters of shaft tuyere have vital effects on the gas flow distribution and working condition in the TGR-OBF, which determine the production index, CO2 emission reduction, and economic benefit. To clarify the effects of shaft tuyere parameters on gas movement behavior and burden reduction in oxygen blast furnaces, a 2D steady-state model based on actual plant conditions in China is published in this study. The shaft of the blast furnace can be divided into region I near the wall and region II close to the center, which was influenced by top gas and bosh gas, respectively. The farthest movement distance of the top gas along the radial direction was defined as the penetration depth decided by its kinetic energy ratio. As the height of shaft tuyere decreased from 5/10 L to 1/10 L, the penetration depth decreased from 1.615 m to 1.308 m, and the reduction degree of iron-bearing burden before entering the cohesive zone increased from 0.925 to 0.982. With the shaft tuyere diameters increased from 0.088 m to 0.096 m with a constant blast velocity, the penetration depth was kept elongated at 1.24 m, and the reduction degree before entering the cohesive zone increased from 0.972 to 0.983. While the blast volume of top gas was kept constant, the reduction degree before entering the cohesive zone increased from 0.969 to 0.986. When the shaft tuyere angles increased from −20° to 20°, both the distribution of temperature and CO fraction moved towards the upper shaft slightly, and the penetration depth was kept around 1.24. Under experimental conditions, a low-height shaft tuyere was appropriate for an oxygen blast furnace. Within a certain control range, the changes of shaft tuyere diameters and angles had a small effect on the oxygen blast furnace.