Model Study of Centre Coke Charging in Blast Furnace through DEM Simulations
Arijit Chakrabarty, Saprativ Basu, Samik Nag, Ujjal Ghosh, Mantu Patra
Abstract
To enable centrally working blast furnace for smooth operations, the practice of dumping larger sized coke particles, also known as centre coke, in the furnace centre has been developed and adopted in many blast furnaces worldwide. Centre coke will allow the furnace gas to pass more easily through it, thus concentrating much of the energy and mass transfer in the furnace centre and protecting the furnace walls, as well as reduce pressure drop throughout the furnace, among other advantages. In this study, discrete element method(DEM) is used to determine the effect of the geometry and inclination of the rotating chute w.r.t. the vertical on the formation of the centre coke heap in the blast furnace. First, the actual centre coke material is characterised using different experiments. These experiments are then replicated in the DEM simulations to produce a material model that mimics the actual material. Using the material model and geometry of the chute, the distribution of centre coke in the blast furnace is studied. It is found that the stiffeners on the chute have a profound effect on the falling material trajectory. High scatter of material is found at lower inclination angles which decreases with increase in the latter. Conversely, material concentration in the blast furnace is better at lower chute inclination angles. Effect of both on the heap formation of the material is studied and optimum angle at which the chute is to be operated is determined.