This paper presents a method for calculating the basic parameters of the gas jet (average temperature and power) at a certain distance from the nozzle exit in the technology implementation of blowing molten slag on the refractory lining of the converter. The mathematical model has been worked out and the fl ow parameters of the supersonic noncalculated jet, considering joining in the working volume of 350-t converter not only gas but also slag particles, have been calculated. Average weight values of temperature and velocity over the length of the gas jet have been obtained. The effect of the added slag mass on the added mass of gas, the temperature of the gas jet and its rate subject to the changes in the fl ow of nitrogen through the nozzle and the relative temperature in the working space of the converter has been established. The analysis of the results of numerical calculations has showed that the slag ejection changes signifi cantly the picture of the interaction of ternary supersonic noncalculated jet with the melt, at the same time even a slight attachment of slag to the gas fl ow promotes noticeable decrease of the propagation velocity of the jet.

Using a static model of two-speed motion of the gas suspension in gunning-lance it is shown how the powder concentration, carrier gas pressure,particle number density, equivalent diameter, shape factor, differential velocity, and dynamic phase slip have an effect on the aerodynamic drag coefficient, interfacial interacting force, inclusion volume fraction of gas phase, and velocity of soaring.

A method is proposed for calculating the basic parameters of a gas jet (its mean mass temperature and power) at a certain distance from the nozzle when slag melt is sprayed onto the converter’s refractory lining. On the basis of a mathematical model, the flow parameters of a complex supersonic jet are calculated, in conditions where not only gas but slag particles are injected into the working volume of a 350-t converter. The mean mass temperature and velocity are determined over the length of the gas jet. The influence of the added slag mass on the mass of added gas and on the gas jet’s temperature and speed is established, with variation in the nitrogen flow rate through the nozzle and the relative temperature in the converter’s working volume. Analysis of numerical results shows that slag injection significantly changes the interaction between the supersonic jet and the melt. Adding even small quantities of slag markedly slows the jet.

The influence of the powder concentration, carrier-gas pressure, particle density, the equivalent diameter and shape of the particles, the difference in speed of the solid and gas phases, and their dynamic slip on the aerodynamic drag in the guniting lance, the force between the solid and gas phases, the content of gas phase, and the terminal velocity is established by means of a static model of the two-speed motion of the gassuspension in the lance.

A method is proposed for thermally insulating the hearth tubes of continuous heat-treatment furnace No. 3 in the plate shop at the Mariupol Metallurgical Combine with the use of ceramic fibers protected by refractory concrete. Results are presented from the use of furnace No. 3 with the experimental thermal insulation.

A new concept is presented for the design of the dust duct and lance, based on a two-speed approach. Results are provided for studying the effect of powder concentration on the distribution of some parameters throughout the whole line, i.e. from the powder feeder to the lance nozzle. Results are obtained with use of a model of a two-speed gas mixture stream.