Simulation Study Of Liquid Motion And Process Optimization For Shaking Ladle Used In Ferroalloy Production

Shaking ladle is an important equipment in the process for producing ferroalloys, and it is mainly used to produce medium and low carbon ferromanganese as well as low carbon ferrochrome. The size of shaking ladle increases with the increase of the capacity of submerged arc furnace. It can not meet requirements of the actual production to design large-scaled shaking ladle and to optimize parameters of shaking ladle relying solely on producing experience. The designation of large-scaled shaking ladle and its technological optimization need relevant technological guidance, one of which is the motion of the fluid in the shaking ladle under eccentric rotation. In this paper, the motion characteristics of single phase fluid and two phase fluid in the shaking ladle are studied systematically by cold state simulation experiments,and it is proposed that the process of shaking ladle for producing ferroalloy can be optimistized by using some technology of steel making.The motion law of the single phase fluid in the shaking ladle with deionized water was studied and results show that the motion state of the single phase fluid is independent of the position of the fulcrum in the shaking ladle. The number of support points and the touching of support points and the table have little influence on the motion fluid in the shaking ladle. For single-phase fluid, with the increase of rotating speed of the shaking ladle, the flow pattern will undergo five kinds of changes: the state of flat swing; the state of the saddle surface rotation; the state of mono-breaker wave motion; the state of the multiple-breaker wave motion; the state of rotating paraboloid motion. With the increase of the height of the water phase in the shaking ladle, the critical speed increases in different flow patterns.The motion law of the two-phase fluid in the shaking ladle when rotating speed of the shaking ladle increase under conditions of different eccentricities and volume ratios of oil to water was studied with using deionized water to simulate ferroalloys and using machine oil and vegetable oil to simulate slags, and conducting motion simulation experiment of two-phase fluid in shaking ladles with different diameters. Results show that under the condition of the same oil / water volume ratio, the critical speed of the lotus-leaf-shaped flow decreases as the diameter of shaking ladle increases, and it also decreases with the increase of the eccentricity. Under the condition of the same eccentric distance, when the oil / water volume ratio increases, the critical speed of the lotus-leaf-shaped flow becomes larger. Under the condition of the same volume ratio of oil to water, when the eccentricity increases, the critical speed of the lotus-leaf-shaped flow becomes smaller. The quantitative relationship between the critical speed and the eccentricity, the gravity acceleration, the diameter of the roll, and the height of oil and water were obtained through the dimensional analysis and fitting regression of the experimental data:In order to further study the law of periodic variation of interface waves,the eccentric rotary motion in oil/water two phase was observed with a high speed video camera. Results show that the period of free surface wave is the same as that of rotation of shaking ladle and the period of the interface wave is two times of that of rotation of shaking ladle. According to the definition of Faraday wave, the lotus-leaf-shaped interface wave is a new type of Faraday wave in the two phase fluid under eccentric rotary motion.In order to further optimize the existing refining process of shaking ladle, it is first proposed that slag splashing process of large-scale shaking ladle uses the technology of slag splashing in steelmaking for reference to reduce lining erosion of the large-scale shaking ladle and to improve the service life of lining. At the same time,it is firstly proposed that a long-and-short leg RH refining furnace which use RH refining furnace in steelmaking for reference and can be developed to be a new kind of equipment to stir liquid phases of slags and metal, which can promote high efficient mixing of slags and metal in the process of producing ferroalloys.