Radial ore loads distribution at the formation of four-skip ore and coke layers in a blast furnace

Abstract

The objective of the article is to investigate analytically the distribution of ore loads on coke along the blast furnace top radius after the charging with a bell-type charging equipment by means of cycles that ensure the sequential stacking of four sinter skips and four coke skips in a materials column at different separation according to supplies with an increase of ore load to coke ratio from 3,5 to 5,0 kg/kg. Mathematical modelling was carried out under conditions of loading the charge on a horizontal surface and laying a ridge of materials near the top walls. The ore load on coke was established in the cycle of supplies of 4S↓ 4C↓ at which the lengths of the sinter and coke along the top radius are aligned. Surpassing sinter length along the top radius as compared to the coke length prevents the creation of a gas-permeable axial zone. The blast furnace charging with separate increased supplies ensures the most uniform distribution of ore loads on coke along the top radius, close to the total ore load in 4S↓ 4C↓ cycle. The nC (3-n)S↓ (n+1)S (4-n)C↓ charging cycles with the number of skips n = 0, 1, 2 contribute to a greater sinter concentration in the peripheral and intermediate zones of the top during the formation of four-skip ore and coke layers. The charging cycles of 3S↓ S4C↓ supplies showed an excessive concentration of ore material near the walls with a sharp decrease of ore load to the top center. A more uniform distribution of radial ore loads, increased compared to the total ore load, is ensured by charging the charge according to C2S↓ 2S3C↓ cycle. A greater extent of the ore ridge is achieved by charging the charge according to 2CS↓ 3S2C↓ cycle