Effect of high temperature stress on the service time of high alumina refractory bricks
When the temperature changes, thermal stress occurs due to the inability of the object to expand completely and freely due to the external constraints of the object and the mutual constraints between the internal parts. Refractory high-alumina bricks expand thermally at high temperatures and are prone to axial expansion and kneading stress, which is one of the important reasons for refractory high-alumina bricks to open and close kilns. For example, magnesia-chromium or spinel bricks, the expansion rate at 1400℃ can be calculated as 1.6%. The expansion amount of a 198mm long refractory high-alumina brick can reach 3.17mm. With such a large expansion amount, if the ring joint cannot be maintained correctly , too large or too small will cause the refractory high alumina bricks to draw, fall off and fall off, seriously shortening the service life of the refractory high alumina bricks.
Effect of mechanical stress on service time of high alumina bricks
Axial movement of the rotary kiln. The rotary kiln is supported by belts, supporting wheels, and supporting rollers. Its axis should be the line connecting the center points of each cross-section circle of the kiln, and it should be a straight line. However, after the kiln barrel is installed and part of the barrel is replaced, or the kiln body passes through a period of time After operation, the axis of the kiln body will shift due to the influence of thermal load and load. After long-term operation, the tire belt and the roller will wear, the roller will deviate from the outside to the inside, and the stress of each support will change. Especially when the support is too stressed, it is easy to form the roller bearing bush. Burning damage, abnormal peeling or cracking of the surface of the wheel belt and the roller, which further aggravates the axial deflection of the kiln body, causing the refractory high alumina bricks to be extruded and deformed, causing fracture or falling off. After the high-alumina refractory bricks are damaged, the shape will be deeper.
