| The change of flow field in the continuous casting mould will affect the quality of slab.Monitoring the flow rate of molten steel in the mould is very important to improve the quality of slab.The continuous casting mold is a strong heat exchanger,and the molten steel is in the flow state in the continuous casting mold.Aiming at the problem of molten steel flow velocity in the continuous casting mold,a new flow velocity measurement method using graphite rod as the velocity measuring element is proposed based on the principles of heat transfer,hydrodynamics and thermoelectric effect.In this paper,the construction structure,operation condition and material of the mould are investigated.The relationship between flow,heat transfer and thermoelectric effect is analyzed when the velocity measuring element is inserted into the liquid metal.The formula for calculating the flow rate is derived.The main conclusions are as follows.(1)After inserting a conductor rod and forming a closed loop between them,a heat-related electromotive force can be generated by Seebeck principle,and the electromotive force is also related to the flow velocity in the coupled field of temperature field and flow field.(2)The theoretical model was put forward based on the principles of heat transfer,hydrodynamics and thermoelectric effect,and the derivation formula of flow rate was deduced.(3)The experimental results at low and high temperatures show that the measurement method based on heat transfer and flow principle and Seebeck effect is feasible.(4)The flow velocities at 5 cm,5 cm and 10 cm below the slag line are measured by the above formulas.When the casting speed is 1.5 m/min,the velocity of 5 cm under the slag line is 0.000244 m/s and 10 cm is 0.000007 m/s;when the casting speed is 2 m/min,the velocity of 5 cm under the slag line is 0.000263 m/s and the velocity of 10 cm is 0.000013 m/s.(5)The molten steel hardly flows at 5 cm near the straight-tube nozzle and 10 cm below the slag line. |
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