Method for measuring liquid level fluctuation of crystallizer and flow field symmetry

Abstract

The invention relates to a method for measuring liquid level fluctuation of a crystallizer and flow field symmetry. The method includes the specific steps that in the actual pouring process of a single row or multiple rows of steel nail plates manufactured according to the size of sections of the crystallizer and a water gap, the two sides of the water gap are simultaneously and vertically inserted into the liquid surface of the crystallizer and taken out simultaneously and vertically after a few seconds; the diameter of a metal block attached to each steel nail, the height difference of each metal block on the two sides of the corresponding steel nail and the distance from the highest point of each metal block and the tail end of the corresponding steel nail are measured respectively; the three-dimensional outline of the liquid surface of the crystallizer and the flow speed of molten steel from a narrow surface to the water gap in actual production can be obtained at the same time through the measured information; and the three-dimensional outline of the liquid surface of the crystallizer and the fluctuating value and average value of the flow speed in the pouring process are analyzed by inserting the nails on two sides of the water gap many times, and by comparing the flow symmetry of molten steel on two sides of the water gap with the water gap central line as the center, the liquid level fluctuation of the liquid surface of the crystallizer and flow field symmetry are determined.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy and steelmaking, and in particular relates to a method for measuring liquid level fluctuations and flow field symmetry of crystallizers in actual production. Background technique [0002] The flow of molten steel in the continuous casting mold is a complex three-dimensional turbulent flow, which includes many complex phenomena, such as the turbulence in the nozzle and the mold, the movement of bubbles and inclusions, multiphase flow, and the influence of electromagnetic force on the flow of molten steel. Influence, heat transfer, interfacial phenomena, slag reactions, and transfer and segregation of solute elements. Among them, the liquid level fluctuation caused by the turbulent flow of molten steel in the mold and the asymmetric flow on both sides of the nozzle are important reasons for slag entrainment, which will lead to an increase in the defect rate of the slab and an increase in the...

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Problems solved by technology

Among them, the liquid level fluctuation caused by the turbulent flow of molten steel in the mold and the asymmetric flow on both sides of the nozzle are important reasons for slag entrainment, which will lead to an increase in the defect rate of the slab and an increase in the grinding rate, which greatly increases the production cost

However, in the pouring process, in order to melt the mold slag and maintain the temperature of the antegrade liquid surface at about 1500°C, under this condition, the flow form of the molten steel in the mold, the fluctuation of the liquid level, and the symmetry of the molten steel flow on both sides of the nozzle There is no way to know, and it can only be judged indirectly through the defect rate of the slab

Although physical simulation or numerical simulation can be used to study the influence of continuous casting conditions on liquid level fluctuation and flow field symmetry, its authenticity and reliability are questionable if there is no actual measurement result for verification.

[0003] In recent years, some scholars have used the method of inserting steel nails into the liquid surface of the mold to study the flow rate of molten steel on the liquid surface of the mold during the pouring process. The flow rate of molten steel at the position cannot obtain the entire liquid surface profile, so it is impossible to study the liquid level fluctuation, and only insert the mold liquid surface on the side of the nozzle, and it is impossible to study the symmetry of the molten steel flow on both sides of the nozzle

Therefore, the research on the fluctuation of the mold liquid level and the symmetry of the molten steel flow on both sides of the nozzle in the actual pouring process is still a blank

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