Modeling of thermogasodynamic parameters of neutral gas jets when spreading in converter cavity

Abstract

The article considers the features and characteristics of spreading of neutral gas jets in the gas-dynamic section before interaction with the slag melt, which is further inflated to apply a refractory skull to the unit lining. The flow of a supersonic jet into the working space of the converter after tapping has the wave structure. The model for calculation of attached mass of the surrounding gas located in the converter working space is considered. The problem statement takes into account the known data on gas dynamics during the formation and flow of the jet, which affect the efficiency of turbulent transfer in the boundary layer. The calculation scheme is based on the hypothesis of existence of an initial boundary through which a chemically active gas from the environment penetrates into the gas jet, and the shape of the limit boundary is assumed to be cylindrical with a radius equal to the maximum radius of the first barrel of the non-calculated jet. Numerical calculations make it possible to determine the average mass velocity and temperature in an arbitrary section of a supersonic non-calculated jet before its introduction into the slag melt. The authors describe the influence of the relative temperature θ, nitrogen temperature in front of the nozzle T0 during spreading of the jet in the converter cavity, and nitrogen flow through the nozzles Vн on value of the attached mass q, the averaged values of velocity and temperature Wx and Tx in an arbitrary cross-section x of a supersonic non-calculated jet in the gas dynamic section. The information obtained can be used in the development of gas-powder purging systems in aggregates and steel ladles, shotcrete systems and the supply of neutral gas jets when replacing oxygen flows during purging and using two-tier tuyeres.