Experimental And Numerical Simulation Research On The Gas-Liquid Stirring Characteristics Of Immersion Top-Blown From Single Orifice

It is very common that the liquid phase is stirred by the bubbles which are formed from a top-submerged orifice,and the process is often applied in the field of metallurgy,chemical and biology.A series of favourable effects like sufficient mixing,temperature uniformly distributed and inclusion removal can be achieved by the gas injection.Therefore,it is of great significance to conduct a further research on the top-submerged blow to guide the production and design in the industry.Experimental and numerical investigations have been performed on the regularities of flow field from a top-submerged single orifice,based on the existing researches on the mixing of gas and liquid.The work can not only provide widely applicable theories and methods for the evaluation methods of stirring effects in gas-liquid flow,but also supply basic technical support for the industrial production.The main research works are as follows:(1)The research model of the gas-liquid stirring characteristics of immersion top-blown from single orifice in this paper was modelled.Water model experimental platform of the immersion top-blown from single orifice was built in the experiment design,and high speed camera was used in photographing.Obtained consecutive pictures of different gas flow rate and nozzle insertion depth.Statistic and analysis of bubble detach size which was based on stirring power in different working conditions were carried out.(2)In order to quantify the stirring effect of liquid phase accurately and comprehensively,similarity computing method based on image partition strategy and NCC algorithm was proposed by the image characteristics on the premise that professional instruments were not used.And the similarity method was applied to evaluate the stirring effects of liquid phase under different test conditions.(3)The 3D numerical simulation of water model experimental of the singe orifice top-submerged blow was performed.Analyses were conducted on the characteristics of flow field inside the container.The bubble detach size and proportion of dead zone in the simulation were compared with the bubble detach size and stirring effects in experiment.The effectiveness of the grid generation method and calculationmodels for the numerical simulation of submerged blow were verified with above work.(4)Further numerical simulation was carried out for the top-submerged blow of double layer insoluble liquid from a single orifice.The characteristics of flow field inside the container and the motility parameters of surface liquid were predicted.The research was helpful to explore the optimization for the related technological parameters in specific processes in metallurgical industry like auxiliary deslagging process by pouring air from top orifice in hot metal tank and so on.