Common problems in the application process of diffused breathable bricks

Common problems in the application process of diffused breathable bricks

In order to improve the service life, bottom blowing effect and safety and reliability of the bottom-blown argon permeable brick for refining ladle, a new type of diffused permeable brick is developed using a combination of permeable inner core and dense high-strength material. The production process is relatively simple, so it is widely used. Today, the editor will introduce some common problems in the application process of the new type of diffused ventilation bricks.

1. Installation situation The new type of diffused permeable brick must ensure that the tail steel pipe thread is not damaged during the transportation and installation process, so as to avoid poor pipeline connection and air leakage, which will affect the flow rate and blowing rate of argon blowing. During the installation process of the permeable brick, ensure that the tail Steel pipes should not enter dust and debris, etc., and the working surface of breathable bricks should not be covered by fire mud or other materials, so as to avoid unsuccessful bottom blowing. During installation or use of breathable bricks, ensure that the pipes are tightly connected and leak-proof, and should be checked frequently .If there is gas leakage, the gas escapes from the leak with a large partial pressure, and the argon pressure blown into the molten steel through the breathable brick is not enough to blow up the molten steel, affecting the stirring effect, resulting in a decrease in the blowing rate.

2. Gas source conditions The purity of argon used for blowing and stirring of the new type of diffused permeable brick should be greater than or equal to 99.99 percent, and its oxygen content should be strictly controlled below 8ppm, generally around 3ppm. Argon gas with a serious oxygen content exceeding the standard When passing through the working face of the breathable brick, the high temperature melting loss of the breathable brick will be accelerated due to the oxygen flux on the working face of the breathable brick. The light one will generally reduce the life of the breathable brick, and the serious one will lead to the accident of the breathable brick passing through the steel. Especially in the oxygen production plant During maintenance, the oxygen and argon pipelines are not allowed to be connected incorrectly; the purity of bottled argon should be strictly checked.

3. Brick core maintenance The new type of diffused and breathable brick brick core is an easily eroded part. After the brick core is eroded, the middle is concave pit shape. It is easy to burn oxygen to corrode the brick core and reduce the life of the brick core. Therefore, it is stipulated that after the steel is poured, the air source (compressed air) is immediately connected to the ladle turntable to blow out the accumulated steel in the recessed part of the center of the breathable brick. After the ladle is turned over and the slag is poured, Put it down in the hot repair area, connect the nitrogen gas to detect the flow rate of the breathable brick, and it will not be processed if the flow rate requirements are met. If the flow rate cannot meet the requirements, the oxygen-burning backflushing measures are adopted. Use an oxygen lance to remove the cold steel cold slag from the concave part of the surface of the breathable brick. When burning oxygen, keep a distance of 50mm between the front end of the oxygen lance and the working surface of the breathable brick, shorten the oxygen burning time as much as possible, avoid the melting damage of the core of the breathable brick, and artificially reduce the use of the breathable brick. life.

4. The safety display problem is in the middle and later stages of the use of the breathable brick. According to the number of times the ladle is used (it is recommended to be about 35-40 times), the diffused breathable brick can be slightly burnt with oxygen intermittently to observe whether the safety display of the breathable brick is exposed or not. The hot repair workers are required to have a high sense of responsibility, and the ladle can be immediately considered offline when the slit is exposed, and the safety is high.