Methodology for calculating parameters of swirling jets as applied to TSL lance

The TSL lance operates in the mode of swirling cocurrent jets of cooling air and the oxygenair mixture (OAM). This ensures its cooling when immersed in the melt and organizing high-temperature autogenous melting processes in Ausmelt® and ISASMELT™ furnaces. Rotation of the blast torch improves mass transfer in the furnace and increases its productivity. Consideration of the theoretical foundations of the cocurrent jet swirling processes allowed developing a method for calculating their main parameters for melting conditions in the Ausmelt® furnace and to make a mathematical analysis for various blast modes. In accordance with the assessment, the dependence of the effective swirl both on the design swirl and on the amount and speed of the blast mixture flow from the swirlers can be observed. An increase in the effective swirl of cocurrent jets creates the prerequisites for reverse currents forming at the lance mouth; the diameter of its funnel becomes comparable with the diameters of the inner tubes of the lance. An increase in the diameter of the funnel of reverse currents is accompanied by an increase in the angle of the jet opening and a decrease in the depth of penetration of the blast torch into the melt. To evaluate the swirling efficiency, a model for its calculation is proposed for Ausmelt® and ISASMELT™ furnaces. Monitoring the swirling parameters allows predicting the process parameters of melting and effectively managing the raw material processing. When understanding the parameters of the design swirl for a specific lance used, a furnace operator can control the condition of the lance tip by changing the backpressure (resistance) controlled by the devices without removing it from the melt, thereby optimizing the melting mode and reducing the downtime for lance maintenance.