At the later stage of casting, the corrosion of nozzle caused the casting speed to be too fast, which had a negative impact on the quality of continuous casting slab. In order to increase the number of blast furnace continuous casting furnaces, the tundish needs to be replaced frequently. The results show that there is too much residual steel in tundish and more scrap in continuous casting billet. More seriously, in order to reduce the occurrence of these events, many steelmaking enterprises began to quickly replace the sizing nozzle. Let's look at the principle of quickly changing the slurry nozzle:

The difference between the manual swing tundish quick-change mechanism and the hydraulic quick-change mechanism is that the driving force is different. During the pouring process, the sliding nozzle is eroded by molten steel, the inner diameter increases, and the flow of molten steel increases. When the drawing speed exceeds the specified range, the sizing nozzle shall be replaced manually and quickly. The manual pendulum mechanism does not need a hydraulic drive device, and only needs to manually complete the rapid replacement process of the sliding nozzle through the lever principle. The slurry nozzle quick change system consists of two closely combined sliding nozzles. In the working state, the center lines of the inner holes of the upper and lower nozzles coincide to ensure the smooth steel flow.

The slurry nozzle is mainly used for billet continuous casting and can control the flow of molten steel. The sizing nozzle has good thermal shock resistance and corrosion resistance, ensuring that molten steel flows into the mold evenly and stably through the sizing nozzle, ensuring the normal operation of the continuous casting process and improving production efficiency. The corrosion resistance of molten steel and slag is good. The manufacturer of tundish upper nozzle points out that high-purity zirconium, CaO stabilized ZrO2 and zirconia industrial nozzle are generally used. Good thermal shock resistance, zircon decomposes at high temperature, and ZrO2 has a very high coefficient of thermal expansion. Therefore, this product overcomes the above shortcomings, so that it has a certain thermal shock resistance and does not crack in use.

The replacement equipment has a good nozzle runway. In the working state of the sliding gate and the spare nozzle is positioned on the ramp, so that the new grading drainage pipe is connected to the nozzle on the brick, and the steel flows into the mold through the new tundish size, so as to realize the rapid replacement of nozzles in the grading continuous casting process. It is tightly pressed on the lower surface of the upper nozzle through the action of the pneumatic spring. Make the upper and lower openings closely connected. Due to the yield characteristics of the spring, the nozzle with insufficient slurry can move smoothly in the slider during replacement.

The above is the working principle of rapid replacement of slurry nozzle. By using this technology, the nozzle can be changed quickly without affecting the smelting, thus improving the output of continuous casting steel and the quality of continuous casting billet, reducing the consumption of raw materials and reducing the cost.