Analysis of Structural Characteristics of Dispersive Breathable Bricks

 Due to the special structure of the dispersion block, the dispersion-type air-permeable brick avoids the problem of the slit steel of the slit-type air-permeable brick, and can ensure good air permeability; the air bubbles are small and uniform, and the bottom blowing and mixing effect is good. It is because of these The function of the dispersion type ventilation brick has been widely used. Today, the editor will give you a specific introduction to the function of the new type of dispersion type ventilation brick for the pure ladle.

1, Internal structure

The diffused ventilation brick needs to make the bottom round table and the dispersion block first, and then form the brick core like ordinary slit ventilation bricks, and the production process is more complicated.

2, Physical and chemical indicators

In order to ensure the long life of the dispersive block, the high-specification synthetic raw materials with high strength, high refractoriness and excellent corrosion resistance are selected, and the combined structure of the breathable inner core and the dense high-strength material is adopted.

1, Microstructure

newDispersion type breathable brickBecause of its microstructural characteristics, there will be no impermeability or poor bottom blowing of the slit sandwiched steel structure that the original slit-type ventilation bricks often present. With a large temperature gradient, part of the thermal stress generated will converge near the slit, especially the thermal stress at the outlet of the slit is larger, which will change the standard of the slit during use, resulting in the molten steel simply intruding into the slit to form a bottom blowing failure. In addition, if the bottom blowing valve is quickly closed at the end of the purification process, the molten steel will enter the slit with positive pressure, so it is necessary to install a reverse osmosis check valve on the argon blowing pipeline. Therefore, the slit type breathable brick must be suitable and stable The standard slit airway standard and the raw material with better thermal stability can reduce the slit steel. The ventilation channel of the dispersive breathable brick is a large number of connected pores dispersed inside the brick body. These micron-scale curved channels constitute the penetration of molten steel. The larger resistance of the steel is basically non-penetrating in actual use. The air bubbles generated by the dispersive breathable brick are small, uniform and full, and it is easier to stir the molten steel to a uniform temperature, and it is easier to promote the floating of inclusions to achieve better quality. effect.

4, thermal stability

The new diffused type permeable brick is not easy to cause cross-section of the brick core surface. When blowing argon, the ordinary slit type permeable brick is in direct contact with the high-temperature molten steel at the outlet of the slit, and the cold air flow continuously flows out, resulting in a large temperature gradient, forming a slit The thermal stress at the air outlet is particularly large, coupled with the rapid cooling and rapid heating effect during use, it is easy to cross the air outlet near the slit, causing the slit to shift and the bottom to blow through. The thermal stress of the dispersive permeable brick is easy to form the cross-section of the slit-type breathable brick, which puts forward relatively high requirements for the thermal shock resistance of the refractory material. However, there are micron-scale gas channels on the entire working surface of the dispersive breathable brick. The temperature gradient is small, so the new diffused and breathable brick is not easy to cause cross-section of the brick core surface.