1) Structural characteristics of ladle cover
After a detailed understanding of the operating temperature and operating environment of the ladle cover of the steel mill, combined with the characteristics and performance of the lightweight and high-strength castables, the lining structure of the ladle cover is determined as a vulnerable part (the center of the cover with strong molten steel radiation has a diameter of about 1.5 meters), using 140mm lightweight and high-strength castables, and other parts using fiber blankets of 140mm. Most of the anchors are in the form of Y-shaped structure, the distribution spacing is 200mm, and the total height of the anchors is 70mm and 50mm.
2) Advantages of using lightweight and high-strength castables
(1) It has excellent properties such as thermal insulation, good thermal insulation performance, no thermal expansion stress, thermal shock resistance and mechanical vibration resistance.
(2) It is light in weight and has an average bulk density of only 1.7g/cm³. It is used to replace traditional heavy refractory materials, which can effectively strengthen the thermal insulation structure of the ladle cover and effectively reduce the load-bearing load of the transmission structure of the ladle cover.
(3) The overall structure of the ladle cover lining is uniform; the construction is convenient and easy to repair.
3) Scope of application
It can meet the needs of various industries, product forms and technical performance within the range of 300℃ to 1500℃.
The use of the lightweight and high-strength castable structure of the ladle cover ensures the normal operation of the ladle cover automation system, which enables the ladle cover to remain on the ladle during almost the entire ladle life cycle. The benefits include:
1) The service life of the ladle cover is greatly improved, from less than 300 heats for heavy castables to about 450 heats, reducing production and maintenance costs.
2) The cooling rate of molten steel in the ladle and the cooling rate of the empty ladle are reduced, and the temperature of molten steel can be reduced by 30 to 40 °C, which can eliminate the need for on-line preheating of the turnover ladle.
3) Reduce the temperature fluctuation of molten steel in the ladle, reduce the generation of scrap steel in the ladle, and improve product quality.
4) Reduce energy consumption and improve the working environment of workshop operators.
5) The cost savings per ton of steel that can be achieved are generally between 20 and 25 yuan, and every 1 million tons of steel can save 8 million to 13 million yuan.
6) Energy saving and emission reduction. The oxygen blowing temperature of converter tapping is calculated at 5Nm³/℃ per ton of steel, and the temperature is reduced by 10℃. The annual output of 5 million tons of steel can save 25 million Nm³ of oxygen. The heating of coke oven gas for online baking is 400Nm³/h for 20min, and the annual output of 5 million tons of steel mills saves 40 million Nm³ of baking gas.