New methods of burden distribution control in bell-armour charging.

Abstract

Under the present situation which is forced to reduce the productivity of the all coke operation, it is important to establish such a distribution adjusting technique as to maintain an adequate peripheral gas flow and a sharp central gas flow simultaneously. The gas distribution in a furnace equipped with a bell-armour in comparison with that of the bell-less top has a tendency to flatten owing to the difference in size segregation behaviour in the radial direction, thus posing a problem in micro-control of the burden distribution.The authors have recently developed a new technique of controlling the burden distribution by the movable armour and applied it to Chiba No. 5 Blast Furnace. The technique is aimed at improving the layer thickness and promoting the particle size segregation in the radial direction, slowing down the raw material discharging rate from the bell by controlling the bell stroke and speed.By the application of this technique, it has made possible to strengthen both the peripheral gas flow and central gas flow simultaneously, and thus has greatly contributed to stabilizing the furnace condition and extention of the permitted limit for operation under the recent circumstances of reduced production.