Experiences During Revival Journey of Chilled Hearth of the Blast Furnace at Rourkela Steel Plant

Abstract

The blast furnace operating at Rourkela Steel Plant suffered the sudden collapse of the top cone of the dust catcher leading to damages to the down-comer, dust catcher and gas cleaning plant. Both the down-comers later fell damaging the cast-house and the furnace top structure. This abrupt stoppage of the furnace led to a chilled hearth filled with metal and slag. To revive the furnace, maximum heat was introduced in the furnace using O₂ and mixed gas heating. Simultaneously lancing was done through tuyere and taphole to establish a connection between them. After the top charged coke reached the tuyere level, the lancing was started through taphole, and when a fair amount of metal and slag started coming out from the taphole, all the tuyeres were plugged with clay except tuyere no. 4 through which wind was introduced in the furnace. Temperature in front of individual tuyeres was the decided parameter for the tuyere opening sequence. With every added tuyere, hot blast pressure (HBP), hot blast volume (HBV) and burden charged were increased. All the tuyeres came into operation within three weeks with only one burnt tuyere during revival.