FORMATION OF A GAS-METAL FLOW UNDER THE CONDITIONS OF «CHEMICAL» VACUUM IN STEEL-TAPPING CHANNEL

Abstract

The results of laboratory research to determine the hydro-gas-dynamic patterns the formation of gas-metal flow at an tapping from an oxygen converter to steel ladle are given due to the injection of subsonic argon jets into the melt flow through nozzles located in the steel-tapping channel.Using the method of low-temperature simulation, determined the influence of design parameters of the proposed design of a two-chamber steel-tapping channel (length of the reaction zone, the number and location of gas nozzles) and gas consumption on the degree of organization and protection of the gas-liquid flow (GLF) when the gas blowing into the working space of the steel-tapping channel.Was obtained mathematical relation characterizing the mutual influence on the opening angle of the GLF between of the relative length of the "reaction zone" (x) and the gas flow rate through the nozzle. It is shown that when the length of the "reaction zone" decreases, an extremum occurs at lower gas consumption, and the value of "subcritical" gas consumption has a greater range. So, when the length of the "reaction zone" decreases, an extremum occurs at lower gas consumption, and the value of "subcritical" gas consumption has a greater range.The possibility of retaining the angle of disclosure of the gas-liquid flow (α) in the range of up to 5° with a relative length of the reaction zone of 0,75 has been proved. It is shown that with an increase of α from 1...3° to 10°, the efficiency of the protective action of argon (k) decreases from 0,99 to 0,72. At x = 0,75, the coefficient k is in the range of 0,89...0,99. It is established that when the critical gas flow is exceeded and x = 0,25, the value of α rises to an inadmissible 10...15°.The classification of the purges of the melt flow in the steel-tapping channel is proposed, depending on the angle of inclination of the gas jets relative to the axis of the last (γ) in accordance with which are allocated: the mode of "interruption" (γ > 78°), at which the gas jets unclosed, the formation of the gas-liquid flow does not occur; the mode of "closing" (0 <γ <78°), in which gas flows are combined, a gas-liquid flow with a developed interfacial surface and a high degree of organization is formed, and the mode of "breakdown" (γ = 0°), at which a further increase of gas flow rate exceeding the critical one leads to breakdown and movement of the gas-liquid flow in dispersion-ring mode with a decrease in the degree of organization of the flow.