OPERATING CONDITIONS AND STABILITY FIRE RESISTANT LINING SUBMERGED LANCE

Abstract

To ensure the reliable and long—term operation of submersible lances used in the processes of bucket desulfurization of cast iron before converter processing, reliable means and appropriate conditions for supplying powdered desulfurizing reagents through nozzles of the lance tip, a rational scheme of refractory lining of the submersible lance and improvement of its operation modes are necessary. The purpose of the work is to study the characteristics of the destruction of the refractory lining of submersible lances, intended for desulfurization of iron—carbon melts by blowing powdery reagents deep into the ladle bath. To realize the goal, we used practical information on the researched question and the method of isothermal modeling of the hydrogas dynamics of a bucket bath using variable designs of the tips of stationary and rotating submersible lances. A comparative analysis and study of the features of the destruction of the lining of submerged stationary and rotating lances in the area of contact with the metal melt (below the "slag—metal" border) during gas injection into the bath was carried out using a 230—t pouring ladle model. During the experiments, T—shaped tips were used (for rotating and stationary lances) and tips with two spray pipe placed at an angle of 45 degrees to the axis of the lance (for stationary lances). Based on the results of data processing, mathematical models were obtained for each of the isolated zones on the lining surface of the submersible lance, and the statistical significance of the sample regression coefficients was checked. The nature and features of the destruction of the lining layer in each of the zones corresponding to the changes in the bath blowing conditions were established. New data were obtained regarding the intensity and depth of wear of the lining of the rotating submersible lance, depending on its speed of rotation and carrier gas consumption. It was established that under the investigated conditions of blowing the bath, the speed of rotation of the lance can be attributed to the factor most influencing the depth and intensity of wear of the lance lining.