Liquid steel nitrogen increasing device and method for controlling steel tapping procedures

Abstract

The invention discloses a liquid steel nitrogen adding device for controlling steel tapping procedures. The liquid steel nitrogen adding device comprises a cylindrical argon plug, electric stop valves and electric flow regulating valves. The cylindrical argon plug sleeves a steel tapping opening, two argon plug rings are uniformly distributed at the lower end of the cylindrical argon plug, and a plurality of argon holes are formed in the two argon plug rings in a staggered manner; a plurality of argon pipelines which are communicated with the argon holes are uniformly arranged in the cylindrical argon plug in a staggered manner; argon metal hoses are externally connected with the argon pipelines and are connected with argon sources, the electric stop valves and the electric flow regulating valves respectively. A method for controlling the steel tapping procedures includes enabling pipeline argon to flow before the steel tapping procedures are carried out; enabling argon in the inner ring and the outer ring to flow at first to form two cone argon layers when the steel tapping procedures are carried out; adjusting the electric flow regulating valves to control the flow of the argon; shutting the electric stop valves when the steel tapping procedures are terminated. The liquid steel nitrogen adding device and the method have the advantages that liquid steel and steel drop are enclosed by two argon cones, accordingly, liquid steel nitrogen adding effects for controlling the steel tapping procedures can be realized, the liquid steel nitrogen adding device is simple in structure and low in manufacturing cost, the method is easy to implement, and obvious effects can be realized.

Description

technical field [0001] The invention relates to a device and method for preventing molten steel from increasing nitrogen, and belongs to the technical field of converter steelmaking equipment. Background technique [0002] With the development and progress of steelmaking technology, customers have higher and higher requirements for the purity of steel. The sum of the five major hazardous elements N, H, O, P, and S in molten steel is preferably about 100ppm, and the content of N element is about 30ppm, which becomes the bottleneck factor for further improvement of the purity of molten steel. Converter steelmaking is divided into iron loading, smelting, steel tapping, slag splashing, slag dumping, furnace repair, empty furnace waiting, etc. Since nitrogen is the main substance in the air, it is easy to be inhaled during the production process from steelmaking to continuous casting Molten steel, especially the direct contact with the atmosphere of molten steel in the tapping p...

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Problems solved by technology

There are two traditional ways to prevent nitrogen increase in the tapping process: one is to ensure the roundness of the steel flow during tapping by maintaining the outer opening of the tapping hole, and prevent the molten steel from absorbing nitrogen; the other is to use oxygen as a surface active element in the molten steel. When the oxygen content in the water is high, the mass transfer coefficient is small, which reduces the amount of nitrogen absorbed by the molten steel; there are three main problems in the traditional control of nitrogen increase in the tapping process: 1) Frequent maintenance of the tapping port takes up the smelting cycle of the converter and affects the production rhythm. Moreover, the maintenance effect of the outer opening of the tapping hole is difficult to guarantee; 2) The oxygen at the end of the converter is high, and the tapping process is slightly deoxidized, resulting in difficulty in tapping; when the oxygen content at the end is low, there is a lack of necessary measures to prevent nitrogen increase in tapping; 3) The length of tapping time It has a great impact on the nitrogen increase in the tapping process, especially the tapping time of the new tapping port is long, and the production of low-nitrogen steel is difficult to guarantee

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