The main purpose of refractory bricks for rotary kiln is to protect the kiln shell from high-temperature gas and high-temperature materials,Refractory Bricks and to ensure normal production. In industrial production, the service life of fired zone refractory bricks is very short,Refractory Bricks which often leads to unplanned shutdown of the kiln for maintenance, which is a key factor affecting the quality, high output,Refractory Bricks low consumption and annual operation rate of cement kilns.
Corrosion mechanism of refractory bricks: Whether it is a wet process kiln or a new dry process rotary kiln, during the clinker calcination process,Refractory Bricks the gas temperature in the kiln is much higher than the material temperature. Every time the kiln rotates,Refractory Bricks the surface of the kiln lining is periodically The thermal shock of the kiln, the range of temperature change is 150～250℃,Refractory Bricks and the thermal stress is generated in the surface layer of the kiln lining 10～20mm. The kiln lining also bears the alternating radial and axial mechanical stress of the brickwork caused by the rotation of the kiln,Refractory Bricks as well as the erosion and wear of the calcined materials.
Due to the simultaneous production of silicate melt,Refractory Bricks it is easy to interact with the surface of the kiln-lined refractory brick to form an initial layer in a high temperature environment,Refractory Bricks and at the same time penetrate into the interior of the refractory brick along the pores of the refractory brick,Refractory Bricks and bond with the refractory brick to make the refractory The chemical composition and phase composition of the brick surface layer within the range of 10-20mm change,Refractory Bricks which reduces the technical performance of the refractory brick. When the sintering range of the material is narrow or the formation of short flame and rapid burning produces local high temperature,Refractory Bricks the minimum temperature of the kiln skin surface will be higher than the solidification temperature of the material liquid phase,Refractory Bricks and the surface layer of the kiln skin will change from solid to liquid and fall off. After reaching the beginning of the kiln skin,Refractory Bricks a new initial layer of kiln skin is formed.
When this happens repeatedly,Refractory Bricks the kiln lining of the firing zone gradually changes from thick to thin, or even completely falls off, resulting in partial exposure of the kiln shell and red kiln. In fact,Refractory Bricks the damage of the kiln lining of the firing zone is exactly the same. The thickness of the residual bricks in the high temperature area is generally distributed in an arc with a larger radius of curvature,Refractory Bricks and sometimes the arc bottom falls on the inner surface of the kiln.
