Thermalphysic processes in a reaction zone of electrothermal ore-smelting reactor

摘要

Considered are the features of hydrodynamics and heat and mass transfer during the reduction reaction proceeding in a coke zone of electrothermal ore-smelting reactor, when the process is complicated by gas phase evolving, which bubbles the melt. The gas bubbles provides conditions for intense immixture, which for it's turn intensifies target reduction processes. The peculiarities of the reacting lies in the fact that an active reagent on mixing transfers the reduction process into kinetic area. In that case, the temperature of a reaction zone and reagent concentration in a volume are the governing factors, so the reduction reaction and gas bubbles evolving influence on development of convection currents is thought of as influence of temperature and reagent concentration. Hydrodynamics of the bubbles and liquid interconnection has its peculiar features like a local Influence over liquid by means of added mass for example. The effect strength is in direct relation of the gas content gradient. It is shown that the chemical reduction reaction rate determines gas content and hence, an extent of influence on immixture. The effective criteria, which characterize the chemical reaction influence by means of heat and concentration effect, have been introduced as a measure of the gas phase impact on hydrodynamics in filter equation. The coefficients, considering the chemical reaction influence on hydrodynamics of the system are well greater than the influence parameters of free and concentration convection, which actually determines the melt behaviour in a reaction zone. In that case, the problem is reduced by structure to an estimation of influence of the temperature and concentration small perturbations on hydrodynamics of the melt being filtered in a coke layer. It is deduced that in a reduction process there takes place the formation of dissipative hydrodynamic structures, which determine thermophysical behaviour of a reaction zone, including temperature and reagent concentrations. Synergetic behaviour features of a reaction bulk provide conditions and possibilities of control. It is precisely the situation that should be taken into account when organizing the operating mode of electrothermal ore-smelting reactor.