PECULIARITIES OF HYDRODYNAMICS AND HEAT TRANSFER DURING ACTIVATION OF CHEMICAL AND ENERGY TECHNOLOGICAL RECOVERY PROCESSES IN COKE ZONE OF ORE-THERMAL FURNACE
This work examines the peculiarities of heterogeneous reactions during bubbling of gas released in the process of reaction upon contact with a solid reducing reagent, taking into account the peculiarities of hydrodynamics and heat and mass transfer during the reduction reaction in the coke zone of the ore-thermal furnace, when the process is complicated by the formation of a gas phase bubbling through the melt. Bubbles form conditions intensifying mixing, as a result of which chemical and energy technological processes of reduction are activated. The main feature of the response is the active diffusion of the reagent due to intense mixing, which shifts the reduction process to the kinetic region. The main factors at this stage are the temperature in the reaction zone and the concentration of the reagent in its volume. The reduction reaction and the formation of gas bubbles affect the formation of convective flows due to the effects of temperature and reagent concentration. Hydrodynamic aspects of the mutual effect of gas and liquid phase bubbles have specific features due to the local effect on the liquid phase. The intensity of such exposure directly depends on the GOR gradient. It has been scientifically substantiated that the reduction reaction rate is the determining factor for the gas content and therefore mixing. To describe the measure of the effect of gas content on hydrodynamics, the filtration equations are supplemented with effective criteria that characterize the dependence of the reduction reaction through thermal and concentration effects. The coefficients determining the influence of the chemical reaction on hydrodynamics are significantly greater than the parameters determining natural and concentration convection, which actually affects the nature of the melt in the reaction zone of the ore-thermal furnace. A meaningful statement of the problem is determined by assessing the effect of small temperature perturbations and concentrations on the hydrodynamic aspects of the filtered melt through the coke layer. It has been established that a distinctive feature of chemical-energy-technological reduction processes is the emergence and formation of dissipative hydrodynamic structures that determine the thermophysical characteristics of the reaction zone of the reduction reactor, in particular the temperature and concentration of reagents. Synergistic aspects of the nature of the reaction volume of the ore-thermal furnace significantly affect the possibility of control, which means that they should be used and taken into account when forming the operating modes of electrothermal reduction reactors.