Sliding nozzle system classification
(1) The sliding nozzle can be divided into two-layer and three-layer slides according to the number of slides. The two-layer skateboard does not move the upper slide while the lower slide follows the mechanism to slide. The two-layer skateboard is mostly used in the ladle mechanism. The upper and lower slides of the three-layer slide plate do not move, and the middle slide plate follows the mechanism to slide to control and adjust the flow of molten steel; the three-layer slide plate is mostly used in the tundish mechanism. The characteristic of the three-layer sliding board is that the sliding board in the middle does not use fire mud, but is fixed with a metal belt panel, which plays a good role in controlling cracks. At the same time, the parallelism of the sliding board must be strictly controlled. In the initial stage of pouring, in order to prevent the molten steel from condensing in the steel channel of the sliding nozzle, a stopper is installed to prevent the molten steel from flowing into the nozzle channel, to keep the molten steel forming the necessary liquid level in the tundish, and to prevent the molten steel from condensing or non-metallic inclusions when replacing the immersion nozzle Block the channel.
(2) There are two sliding nozzles according to the movement mode: linear and rotary. At present, most steel mills at home and abroad use linear mechanisms, and rotary mechanisms are rarely used.
(3) In addition to the classification of skateboards according to their structure and movement methods, they can also be classified according to the material, firing method and molding method of the skateboard. According to the material process, it can be divided into aluminum-zirconium-carbon slides, zirconium slides, aluminum-carbon slides, magnesia slides, metal combined slides, and high-aluminum slides; according to the firing method, it is divided into high-temperature firing slides, medium-temperature firing slides, and non-burning slides . According to the molding method, it is divided into full-material skateboard and composite-material skateboard. At present, domestic steel ladles above 150t use skateboards, multiple continuous casting ladle slides or special steelmaking processes require steel mills to use all-material skateboards. Many steel plants use composite skateboards for ladles below 150t. Most steel mills abroad use all-material skateboards.