The Effect of Screw Design on Solid Behaviors and the Interaction between Solid and Screws in COREX Shaft Furnace

Abstract

COREX shaft furnace (SF) is a typical screw hopper with eight screws evenly distributed at bottom. The design of screws plays an important role in moving behaviors of burdens and interaction between solid. Therefore, a three‐dimensional cylindrical COREX SF model at full scale of Baosteel is established based on the Discrete Element Method to study the influences of the design of screws, and comparisons are made between the old and modified screws of Baosteel. The measure implemented to the modified screw is to decrease screw flight diameters from the pitch 1 to 3 to obtain greater increment withdraw volume along the screw length. The results show that the profile coefficient, increases dramatically at pitch 4 and 5 than that of the old screw. Compared to old screw, descending velocities and flow patterns of modified screw are more uniform in the lower part of SF. The force distributions are similar in the upper part of SF between the two screws, but the small force area in the lower part for the modified screw expands from screw tip to furnace wall, which is much bigger than that of old screw. The abrasive screw wear at the third and fourth pitches are alleviated with the implement of the modified screw, which is consistent with the force distribution in the lower part of SF. Additionally, the total power draw also decreases after the modification. The findings of this work should be useful for the design, control, and optimization of the SF operation.

Research on the Preparation of Sinter for COREX Reduction Process by Varying Basicity and MgO Content

“…As a typical non-blast furnace ironmaking process, the COREX reduction process relies less on high-quality coke than the traditional blast furnace ironmaking process [1][2][3]. Two sets of COREX devices were introduced and built at the Baosteel Luojing steel plant in China in 2007 and 2011 [4].…”

Solid Flow in a Shaft Furnace in Smelting Reduction Process under Circumferential Imbalance Conditions

“…This method can generate detailed microdynamic information of individual particles, such as particle velocity and interaction forces between particles, which is key for understanding the flow of burden materials in ironmaking process. Thus, DEM has been applied to study solid flow in a shaft furnace in smelting reduction process, such as dynamic burden distribution, particle descending velocity, effect of screws on solid flow, and the effect of Areal Gas Distribution (AGD) beams on solid flow . These studies provide useful information on solid flow in shaft furnace.…”