Physical Modeling And Numerical Simulation On The Migration Process Of Parallel Double Bubbles In Liquid

Large amounts of dust is produced in the electric arc furnace(EAF)smelting process,simple stockpile or landfill will cause serious environmental pollution.Though comprehensive utilization of dust can reduce the threat caused by dust stockpile or landfill,it is great meaningful to reduce the production of EAF dust from the sources,which can decrease the dust treatment cost and potential environment hazardous.The decarburization reaction in the EAF steelmaking process generates large amounts CO gas bubbles.The bursting process of these CO gas bubbles is the major sources of dust.In this paper,the physical modeling and numerical simulation were used to simulate the floating and bursting process of two CO gas bubbles in the liquid,in order to find out the law of dust generation by gas bubble bursting and provide the theoretical basis for reducing the dust generation.The numerical simulation was used to study the upward migration of bubble at different process parameters.The results show that the larger the diameter of the bubble is,the more serious the deformation of the bubble is during the ascending process.The greater the viscosity coefficient of the liquid is,the slower the rate of bubble ascends and the more stable the shape of the bubble is.When the parallel double bubbles rise,there is a critical distance of aggregation of the bubbles.If the distance exceed the critical value,the double bubbles are difficult to aggregate.As the initial diameter of the bubbles increases,the critical distance of aggregation of the bubbles increases.The HX-7 high-speed camera was used to record the generation,rise and rupture process of the parallel double bubbles in the simulated molten steel,as well as the rising process in the simulated steel-slag interface.The bubbles moving process was analyzed using Hot-Link and Photoshop software.The results show that the larger the blowing pore size is,the longer the bubble grows in the blower hole and the larger the bubble is.The shape of bubbles in the rising process quickly changed from the spherical into the ellipsoid,and the larger equivalent diameter of bubble is,more flat the bubble shape is.When the blowing diameter is 3mm,the ascending speed in the vertical direction is the largest,and the velocity of the horizontal direction is the largest when the blowing aperture is 4mm.When the blowing gas volume is small,the droplets bursting range is small and it is easy to produce the small droplets.When the gas volume increases,the liquid level fluctuates,and the droplets bursting range is large,and the bursting droplets are mainly produced by the film droplets.In addition,the physical modeling on the effects of different blowing volume,the initial spacing,the height of the collection plate on the generation of droplets were conducted in the process of ascending of parallel double bubbles.The results show that the generated amount of droplets absorbed by the filter paper increase with the increasing of the gas blowing volume.After reaching a certain amount of gas,the surface fluctuates intensively and the amount of splash absorbed by the filter paper decreases.The smaller the horizontal distance between the parallel double bubbles is,the easier the bubbles aggregate,it produces more droplets splash.However,if the bubble diameter is too large,the aggregated bubbles will rupture,it results the amount of spatter decrease.With the gas volume increases,the distribution of droplets on the filter paper increase and distribute scattering.When the filter paper is 10 mm away from the liquid level,the splash generated by the 4mm blowing gas hole is most absorbed.The splash produced by the 3mm blow hole is the most absorbed by the filter paper when the filter paper is 15 mm away from the liquid level.The lager the viscosity index of the slag is,the less the amount of splash absorbed by filter paper is.