Analysis on Formation Processes of Burden Distribution in Blast Furnace

Abstract

Burden distribution in blast furnace is formed through the following four processes:
(1) Burden descends by the gravitational force in the large bell hopper, (2) is discharged from this hopper followed by falling onto the burden bed, (3) moves toward the furnace center to form the slope, and (4) changes the angle of the slope with its descent, becoming a base for next charge.
The processes (1), (2), and (4) have been studied by experiments and theoretical calculations. The main results obtained are as follows:
(1) Burden descent in the large bell hopper is characterized by such a flow pattern that burden descends predominantly in the wall side region of hopper, resulting in the burden mixing and therefore affecting the burden distribution.
(2) The flow rate of burden from the large bell hopper is proportional to time to the 1.5th power after the discharge begun.
(3) The surface angle of burden charged decreases with the burden descent. This behaviour will be explained by such a theory that the burden has a uniform descending velocity over the horizontal section of shaft.