Method and system for full gas cooling of secondary cooling section of continuous casting

Abstract

The invention relates to a method for full gas cooling of the secondary cooling section of continuous casting. The method uses gas that does not undergo oxidation reaction with the high-temperature slab, and the gas is sprayed to the secondary cooling section of continuous casting at a certain speed through a gas nozzle. On the surface of the high-temperature slab, forced convective heat transfer and radiation heat transfer occur on the surface of the high-temperature slab to realize solidification and cooling of the high-temperature slab. According to the difference in pouring steel type, slab casting speed, molten steel superheat and high-temperature slab surface temperature, the flow rate of cooling gas ejected from the gas nozzle is adjusted accordingly to realize the process of dynamic gas distribution in the secondary cooling section of continuous casting. The cooling gas used in the method is recovered by an air suction port and cooled by a gas cooling device, and the cooled cooling gas is delivered to a gas nozzle to realize recycling of the cooling gas. The invention eliminates the oxidation problem of the billet surface in the secondary cooling section of continuous casting, improves the cooling uniformity of the billet and increases the heat exchange efficiency.

Description

technical field [0001] The invention belongs to the field of continuous casting in the metallurgical industry, and in particular relates to a method and system for full gas cooling of a secondary cooling section of continuous casting. Background technique [0002] The high-temperature liquid steel forms a solidified slab shell in the mold of the continuous casting machine, and then enters the secondary cooling section of the continuous casting to continue to solidify. The traditional continuous casting secondary cooling section adopts the water mist cooling method, that is, water mist is sprayed on the surface of the high-temperature slab, and the water mist falling on the surface of the high-temperature slab evaporates and absorbs heat to take away the heat of the high-temperature slab, so as to realize the cooling and cooling of the high-temperature slab. solidification. But this method has the following problems: 1. The water mist falling on the surface of the high-tempe...

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Problems solved by technology

But this method has the following problems: 1. The water mist falling on the surface of the high-temperature slab is affected by gravity, and it is difficult to distribute evenly on the surface of the high-temperature slab, resulting in uneven temperature on the surface of the slab, and then producing solidification cracks or other due to temperature differences. Both cause solidification defects and deteriorate the quality of the slab; 2. The water mist falling on the surface of the high-temperature slab forms a "liquid film" on the surface of the slab, which reduces the heat transfer efficiency; 3. The water mist cooling method causes the surface of the high-temperature slab to form The oxide layer deteriorates the surface quality of the slab, which is not conducive to the monitoring of the surface of the high-temperature slab during the production process, and reduces the metal yield; 4. The water mist cooling method consumes a lot of water and cannot be recycled, which wastes water resources; 5. The water mist cooling method Poor working environment in the secondary cooling section

6. The billet heat absorbed by the water mist cooling method cannot be recovered, resulting in energy waste

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