Numerical Investigation of Coke Collapse and Size Segregation in the Bell-less Top Blast Furnace

Abstract

The coke collapse phenomenon significantly affects the burden and gas distributions, and further gas utilization and CO₂ emission. Therefore, it is necessary to investigate the coke collapse in blast furnace. A three dimensional model of bell-less top blast furnace is established based on discrete element method (DEM). The effects of chute angle, rotating speed and sinter amount on the coke collapse charateristics are then investigated based on this model. The results show that coke profile changes a lot after its collapse and the collapse region is more than 40% of the furnace radius. Sinter amount affects the coke collapse amount much, followed by chute angle and chute rotating speed. The coke collapse region is affected most by sinter amount, followed by chute rotating speed and chute angle. Large chute angle, higher rotating speed and small sinter amount are recommended for practical operation since they help to obtain a lighter coke size segregation along radius.

Burden profiles in the simulation of base model (a) before collapse; (b) after collapse; (c) coke collapse line. (Online version in color.)