Cold Model On Air Dynamic Characteristics Of Central Jet Distribution

Well particle dispersion in the flash furnace is a prerequisite for normal flash smelting. With increase of the intensity of flash smelting, some problems occur with the existing Central Jet Distribution, such as unstable smelting condition, discharging raw material, shortening lifetime of the shaft wall, decreasing in the utilization of oxygen. When the feeding rate dose not increase much, properly adjusting the progress air, distribution air or the central oxygen can make smelting return to well states. However, when the feeding rate increases to a certain extent, it could not effectively improve the smelting condition to adjust the parameters of the nozzle within a certain range. The users depend on the patent owners’technical support of the nozzle, and their understanding of the principle is limited, so the regulation of parameters is not in a wide-range. In addition, when the feeding rate has exceeded the design value, some users believe that this nozzle may have reached the limit.Experimental method was used in this work to investigate the two-phase dynamic conditions of the gas-particle mixing in the nozzle, which can provide theoretical support on adjustment and improvement of nozzle operating parameters. Based on the similarity theory, the experiment model was set up, the parameters such as process air and distribution air flow rates were determined. Segregation function and the particle mass fraction of the designated area are used to reflect the evenness of particle dispersion.The main conclusions are as follows:(1) The horizontal dispersion effect of particles by distributor is not obvious. The distribution air makes the particles disperse horizontally, while the process air can gather particles to the middle of reaction tower.(2) When the flow rate of the process air is small, the particles can be carried into the process air jet by the distribution air jet, and particles dispersion is well in this condition. When the process air flow is strong, the distribution air flow also need to be strong, then the overall downward airflow velocity is larger, the high efficient reaction area moves down.(3) The Red and Fr’are used to study the relationship between the particle dispersion and the gas flow. Moderate dispersion of particles in flash furnace requires that larger Red is associated with larger Fr’, and smaller Red is associated with smaller Fr.(4) By the grey correlation analysis, within the parameters involved in experiment, the process air flow rate is the most important to the particles dispersion, and controlling the momentum ratios of process air and distribution air is the most effective way to control the particles dispersion.