| In today's metallurgical industry in China,metallurgical pool melting is an extremely important method,so the process of metallurgical pool melting is particularly important.There are three kinds of stirring methods: top blowing,bottom blowing and side blowing.The mixing of gas,liquid and solid is involved in the process.It is of great significance for metallurgical process to master the stirring state and mixing characteristics in molten pool and then guide the practice process.Infrared imaging technology is a new and high technology in the field of parameter visualization detection in industrial process.By capturing the temperature of the outer surface of the reactor,the heat transfer efficiency is calculated,the best heat transfer condition is selected,and then the internal stirring condition is judged according to the temperature field.In view of the characteristics of metallurgical bottom blowing molten pool,such as large volume,high internal temperature,and difficult to detect the working medium state inside the molten pool,a physical model of the bottom blowing reactor was built according to the scale.By analyzing the infrared image,the mixing state of working medium inside the molten pool was obtained,and the factors affecting the stirring process were explored.In this paper,based on the visualization of gas-liquid mixing of top blowing gas stirring and the evaluation of mixing effect,a top blowing mixing experimental platform was designed and built with an external infrared imager to shoot and record experimental data under different working conditions.The temperature field change data obtained were intercepted by image processing technology.Then the coefficient of variation and the coefficient of inhomogeneity were used to study and analyze the uniformity of the temperature field change,and the best heat transfer condition of the gas-liquid two-phase flow in the stirred tank was obtained..The main research contents are as follows:1.Design a gas-liquid two-phase top blowing experimental agitator,in which the air is the gas phase and the synthetic heat conducting oil is the liquid phase.During the experiment,infrared imager was used to photograph and image the whole part of synthetic heat conduction oil in the stirred tank of top blowing experiment,and then the temperature matrix was obtained.2.Coefficient of variation and non-uniform coefficient concept and expression,will be the temperature of the matrix data variation coefficient and non-uniform coefficient calculation,and then to get each group of the coefficient of variation and under the condition of non-uniform coefficient changing with time curve graph,and the optimal heat transfer condition,when the parameters of ld respectively gas Q = 1.5 m after/h,The insertion depth of the top blowing nozzle is H=20cm,and the temperature of the synthetic heat conducting oil is T=55?.3.The heat transfer performance of gas-liquid two-phase flow in a top-blown stirred tank is analyzed and studied by using the uniformity coefficient of temperature difference field to find the best heat transfer condition.It can be seen that infrared imaging is reliable for the research data of gas-liquid mixing two-phase flow with top blowing agitator.In conclusion,the experimental study combined infrared imaging technology,digital image processing and mathematical theory method,and provided a new idea for the study of top blowing gas stirring.In short,the infrared imaging technology can be used to visualize the flow pattern and analyze the mixing characteristics of the gas-liquid mixing process,and the agitator designed in this paper and the data processing method used can be extended and applied to other two-phase flow mixing research fields. |
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