During the cement clinker calcination process, the kiln hood is located at a very special position, and it rotates rapidly with the kiln body and is affected by rapid changes in temperature and heat. Therefore, the Refractory Castables for Kiln Hood is a part that needs to be paid attention to and maintained in production.
Why the Refractory Castables for Kiln Hood the Short Service Life?
The castable at the entrance of the kiln is at the end of the rotary kiln. It is easy to cause a large temperature difference in a short time, causing cracks in the traditional Refractory Castables for Kiln Hood. In severe cases, a large area of castable will fall off.
The axial thermal expansion of refractory bricks in the kiln is quite large. If no corresponding measures are taken, the axial stress generated is very surprising. Take magnesia bricks as an example. When the barrel is fired at 300°C, the brick will expand by as much as 50mm than the barrel. When the inner surface of the lining material reaches 1300°C and the outer surface reaches 200°C, the thermal stress of up to 660Mpa will be formed. This huge thermal stress acts on the front kiln hood, causing the back iron to tilt outward, which in turn causes the refractory to loosen and fall off.
The high-temperature clinker continuously scours and abrades the kiln hood part of the cement kiln, making the Refractory Castables for Kiln Hood mechanical damage more intense. In addition, because the metal shell of the kiln is not completely rigid, the ellipticity of the kiln is also affected. Large or small deformations occur in the kiln shell during rotation, causing compression, tension, and shear stress in the kiln lining. Coupled with the continuous relative displacement and local stress between the refractory bricks in the kiln, the castable at the kiln hood fractures and peels off.
Based on the above-mentioned reasons, the conditions for using the lining at the kiln hood are very harsh, and the requirements for Refractory Castables for Kiln Hood are extremely high.
Refractory Castables for Kiln Hood
The Refractory Castables for Kiln Hood include corundum steel fiber castable, kiln hood anti-stripping castable, new-type low-expansion castable, high-strength explosion-proof castable, and corundum mullite castable.
The corundum steel fiber castable is made of high-density, high-melting, tabular corundum as the main raw material, which has the excellent high-temperature performance. The high-temperature alkali resistance is good, and the alkali resistance level at 1350℃ can reach above level 2, which solves the problem of poor alkali corrosion resistance of corundum castables. It has good thermal shock stability and avoids the phenomenon of product peeling and falling off during use.
The kiln hood anti-stripping castable adopts in-situ synthesis reaction technology. The mullite phase is formed in the material matrix part at high temperatures to improve the high-temperature thermal strength of the material. Improve the material structure and mineral composition, and improve the thermal shock stability of the material. The material has a strong resistance to erosion and abrasion at high temperatures. It has excellent alkali resistance, and the alkali resistance level at 1350°C can reach level 2 or higher. The material is moderately priced, cost-effective, and has good results.
The high-strength explosion-proof castable uses raw materials with high purity, low impurities, and high refractoriness. In addition, the composition of the matrix is strictly controlled, and the mullite crystal phase is formed at high temperatures, which improves the thermal strength of the castable and has good thermal shock stability. It also enhances the anti-erosion performance and wear resistance of the castable, and extends the service life. This product is an explosion-proof castable with good anti-cracking performance and can meet the needs of emergency repairs.
Corundum mullite castable is also called corundum mullite wear-resistance castable. The refractory raw materials of corundum and mullite contain abrasion resistance, so they are refractory castables named after raw materials and properties. The characteristics of corundum and mullite castable have the common advantages of corundum and mullite castable. Part of the matrix reacts in situ to form a mullite phase at high temperature, which improves the high-temperature thermal strength and thermal shock stability of the cast lining. It has high temperature and high compressive strength, thermal shock resistance, and structural peeling resistance. Good high-temperature volume stability and thermal shock resistance, high load softening temperature, low high-temperature creep rate, and good chemical corrosion resistance.
Rongsheng Refractory Castable Manufacturer
Rongsheng is a manufacturer with advanced refractory castable production lines. Rongsheng’s monolithic refractories workshop adopts a fully automatic production line with an annual output of 80,000 tons. In the same industry, it is in the leading stage. In the process of accumulating many years of production and sales experience, Rongsheng Kiln Refractory Manufacturer is recognized by customers in more than 60 countries around the world. For more information about Rongsheng refractory manufacturers, or to purchase refractory castables for kiln hood, please contact us. We will provide you with services according to your specific needs.