Numerical Simulation Of Inclusions Removal By Multiple Bubbles In Metallurgical Melt

In the metallurgical process,molten steel that has been smelted in a converter or electric furnace has to flow through reactors such as ladle,tundish,and crystallizer to complete the continuous casting process.How to effectively remove inclusions in molten steel has been the focus of research.The temperature and composition of the molten steel can be uniformed by blowing an inert gas such as argon into the reactor,and the generated argon bubbles can not only absorb the gas in the steel but also adhere to the inclusions suspended in the molten steel.Since the effect of removing argon by blowing argon is good,the equipment is simple and flexible,and does not need to occupy a fixed operating area,so it is widely used in metallurgical processes.There are two main ways to remove inclusions by floating the bubbles:the bubbles adhere to the inclusion particles to remove them;the bubbles’ tail wake entrains the inclusion particles continuously to remove them.Due to the high temperature and invisibility of molten steel,this process can only be studied by means of numerical simulation.In this paper,the Fluent platform is used to simulate the removal of inclusions in bubbles during the rise of multiple bubbles by means of numerical simulation methods and postprocessing using Tecplot software.The VOF method is used to simulate the rising behavior of multi-bubbles,the DPM method is used to simulate the movement of inclusion particles,and a UDF program is written to judge the inclusions being adhered to the bubbles..By changing the conditions of bubble spacing,bubble size,bubble position,and eccentricity of the bubble,the mechanism and effect of multi-bubble rising to remove inclusions were explored.Research indicates:(1)Adhesion removalWhen the bubble diameter is 8 mm and the eccentricity between the two bubbles increases from 20 mm to 30 mm,the number of bubble adhesion inclusion particles increases by 3.58%,but when the distance of bubbles exceeds a certain level,the number of adhesion no longer depends on the distance Increase and increase.The smaller the difference in the size of the plurality of bubbles is,the larger the number of adhered inclusion particles is.For two bubbles with different sizes,the number of adhered inclusions is larger when the small bubbles are above.The diameter of the bubbles is 8 mm,and the distance between the bubbles is 30 mm.When the eccentricity of the two bubbles is reduced from 8 mm to 0 mm,the number of bubble adhesion inclusion particles increases by 26.37%.When it is as small as 0 mm,the number of bubble adhesion inclusion particles increases by 59.6%.When the diameter of the bubble and the distance between the bubbles are constant,the number of bubbles will increase significantly.When the bubble diameter is 8 mm and the bubble spacing is 20 mm,the number of bubble adhesion inclusion particles increases from 200 to 428 when the number of bubbles increases from 2 to 3,which is an increase of 2.14 times.(2)Bubble wake entrainmentWhen the bubble diameter was 8 mm and the eccentricity between the two bubbles increased from 20 mm to 30 mm,the number of bubble inclusion particles increased slightly,but when the bubble distance increased from 30 mm to 40 mm,the number of inclusion particles decreased It is 19.3%,so when the bubble spacing exceeds a certain level,the number of multibubble entrained inclusion particles will be significantly reduced.The smaller the difference in the sizes of the multiple bubbles is,the larger the number of entrained inclusion particles is,and the larger the number of entrainment is when the larger bubbles are above the two bubbles with different sizes.When the bubble diameter is 8 mm and the bubble spacing is 30 mm,the eccentricity of the two bubbles increases from 0 mm to 8 mm.The number of inclusion particles in the bubbles increases by 12.82%,while the eccentricity of the three bubbles increases from 0 mm.When it is as large as 8 mm,the number of bubble-entrained inclusion particles increases by 46.1%.When the diameter of the bubble and the distance between the bubbles are constant,the increase of the number of bubbles will cause the number of bubble-entrained inclusion particles to increase significantly.When the bubble diameter was 8 mm and the bubble spacing was 20 mm,the number of bubble inclusion particles increased from 351 to 461 when the number of bubbles increased from 2 to 3,which increased 1.31 times.