| As a frontier technology in the field of metallurgy, twin-roll casting technics of thin strip makes the near net shape process which combines the continuous casting and rolling technology and heat treatment technology come true. Side sealing system is thought as a key technology in twin-roll casting technics of thin strip. It mainly has four forms, mechanical side sealing, electromagnetic side sealing, gas side sealing and combination side sealing. As the mechanical side sealing has unavoidable flaw in itself, this paper proposes a new type of electromagnetic side sealing scheme to replace it. Electromagnetic side sealing technology can realize the non-contact side sealing of the liquid metal by using the super distance and force effect of electromagnetic field. The structure proposed in this paper is splitting type magnetic yoke electromagnetic side seal structure. It can realize sub area side sealing for end face of the weld pool. What’s more, it can effectively overcome the weaknesses of magnetic induction intensity concentration at the bottom of the melt pool, magnetic pole saturation and magnetic energy loss in the same electromagnetic side sealing device.The research method of this paper is combining theoretical analysis with numerical simulation, and the theoretical basis is electromagnetic field theory based on MAxwell and basic theory of magnetic fluid mechanics. It focuses on the analysis and study of the distribution law of electromagnetic field and electromagnetic force in the side seal end face of the weld pool.The basic equations of magnetic fluid mechanics are simplified, and an infinite plane magnetic field distribution model is built. Electromagnetic pressure, magnetic field intensity and magnetic motive force are derived under ideal side sealing, and the distribution law of three factors is analyzed.The two-dimensional numerical model of electromagnetic side sealing device is established. Based on the two-dimensional numerical model the influence of magnetic yoke shapes, ampere turns of the coil number, the thickness of magnetic pole, pole spacing and frequency of the magnetic induction intensity is analyzed. Ampere turns of the coil number and pole spacing are believed the main factors affecting magnetic induction intensity. According to the results of two-dimensional numerical simulation, silicon steel is selected the material of the magnetic yoke and structure designs of the magnetic yoke and conductive copper pipe are finished. Finally, the overall design of the electromagnetic side sealing device is completed.In the last, the three-dimensional numerical model of electromagnetic side sealing device with splitting type magnetic yoke is established. It focuses on the simulation of the size and distribution of electromagnetic pressure at the side of weld pool to verify the reliability of electromagnetic side sealing device. According to the analysis results, the electromagnetic side sealing device with splitting type magnetic yoke is optimized to guaranteeing high quality side sealing. |
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