polycrystalline fiberThere are two very basic forms of use: fiber lining and full fiber lining. The specific polycrystalline fiber to be used depends on the specific situation of the dense furnace. Then, let's learn how to choose polycrystalline fiber!

When the kiln masonry is intact or can continue to be used after local maintenance, polycrystalline mullite fiber paste technology can be used. With the lining, the fiber becomes the working layer, the temperature of the original working face drops, and the heat storage loss of the entire furnace is also greatly reduced, which is more effective for intermittent furnaces. Reasonable selection of paste fiber thickness is one of the factors that determine whether the investment index is economical or not. A large number of production practice shows that if the thickness of more than 100mm, the heat storage is reduced quite slowly, and the increase of thickness has almost no effect on the heat storage of the furnace wall. The comprehensive benefit analysis results show that the furnace lining is generally about 50mm.

　　polycrystalline fiberIt is a new type of ultra-light high-temperature refractory fiber at home and abroad at present. It is one of the whole Al2O3-SiO2-based ceramic fibers. Its service temperature is 1500-1700, which is 200-400 higher than that of glass fiber. Compared with any dense or light refractory material, its thermal stability introduces the thermal stability of polycrystalline mullite fiber with multi-polycrystalline fiber.

Polycrystalline fiber products are porous products made of fibers with a diameter of 2-5um and intertwined with mullite fibers. Rapid temperature changes will not produce structural stress, will not peel off under rapid cold and hot conditions, and will resist bending, twisting and mechanical vibration. Therefore, without being limited by any sudden change in temperature, cracks or peeling do not occur after several times of quenching and rapid heating. In addition, the refractory fiber product itself is a flexible and resilient porous material, and the expansion of the individual fibers is absorbed by the fibers themselves.

Therefore, when using polycrystalline fibers, there is no need to consider the problem of leaving expansion joints and ovens. The steel structure of the kiln does not need to consider the expansion stress of fiber products, which makes the structure lightweight and saves the amount of steel used in the furnace. Published at 2021-07-30 17:31

Full fiber lining suitable for new kilns. It can more fully reflect the advantages of refractory fiber, such as saving materials, convenient construction, increasing the effective area and volume of the kiln, energy saving and consumption reduction. For the full fiber lining, the thickness should be selected according to the different furnace temperature to meet the requirements of economic lining. Different materials can be selected according to the temperature gradient along the thickness of the furnace. Working surface, thermal insulation layer, cold surface can use the use of different temperature fiber composite materials. The working surface can use high temperature fiber, and the cold surface can use low-grade fiber such as rock wool. The total thickness of the furnace lining varies with the furnace temperature, generally 160mm or more, and the thick furnace lining is 300mm or less.

For the lining constructed by layering fiber method, each layer of fiber must be staggered. That is, each layer of fibers must be caulked. In order to prevent the formation of a vertical gap with the bottom when shrinking at high temperature, the lamination process is characterized in that the fibers are cut into a square shape for lamination, one side of the cut surface is close to the furnace wall, the other side is close to the working surface of the furnace, and the fiber rod is perpendicular to the heating surface, and the thermal conductivity is 30% higher than that of the lamination process.

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