How to Choose Aluminum Silicate Fiber Cotton Material for Industrial Kiln?

How to choose aluminum silicate fiber cotton material for industrial furnaces at different temperatures? As an insulation material for industrial kilns, aluminum silicate fiber cotton is also called ceramic fiber cotton and refractory fiber cotton. It is a new type of energy-saving material with light density, low thermal conductivity, high-temperature resistance, thermal shock resistance, and air erosion resistance. It is widely used in various industrial furnaces and has many advantages compared with ordinary refractory materials.

Generally, when the working temperature is lower than 1000°C, the natural fuel aluminum silicate refractory fiber can be used. When the working temperature is higher than 1000°C, synthetic pure aluminum silicate refractory fiber can be used. For industrial furnaces with a temperature higher than 1100 ° C, use high-alumina pure materials or chromium pure materials aluminum silicate refractory fibers. Refractory fibers should be selected reasonably according to the furnace temperature and temperature gradient curve; however, refractory fibers cannot be selected in the following cases. The parts in contact with molten liquid metal and slag, the parts directly in contact with the flame and the impact of high-speed airflow, and the inner lining that is easy to collide with the heated workpiece and cannot be protected. When the air velocity in the furnace exceeds 13m/s and the refractory fibers have not been specially treated, the heat treatment furnace uses hydrogen as the protective gas. It is not suitable for industrial furnaces to use refractory fibers as furnace linings. Refractory fibers can be placed in the middle and outer layers as insulation materials, which can also achieve energy-saving effects.

Density characteristics of aluminum silicate refractory fiber cotton

The density of aluminum silicate refractory fiber bulk is generally less than 0.1g/cm³. When it is processed into felt or blanket, it is 0.12~0.16, and the denser secondary product is only 0.2. Therefore, its weight is about 1/10~1/5 of ordinary refractory bricks and 1/6~1/4 of general lightweight refractory bricks. Under the same conditions, the heat storage capacity of the furnace wall using aluminum silicate fiber is only 1/24~1/7 of that of ordinary refractory bricks. The heat storage loss is small, especially suitable for heat treatment furnaces that work intermittently.

Thermal conductivity parameters of aluminum silicate refractory fiber cotton

The thermal conductivity of aluminum silicate refractory fiber is much lower than other insulation materials. The thermal insulation effect of a 1cm refractory fiber layer is equivalent to 10cm ordinary refractory bricks, 5cm lightweight bricks, or 2cm thermal insulation bricks. The types of burners designed by Rongsheng Company for industrial furnaces using different materials are different, please inform in advance before ordering.

High-Temperature Stability of Aluminum Silicate Refractory Fiber Cotton

Aluminum silicate refractory fiber is basically stable below 950°C. When the temperature reaches 1000°C, it can be observed through X-ray inspection that crystallization and devitrification of amorphous fibers gradually occur, and the fibers gradually lose elasticity and become brittle and pulverized. When the temperature rises further, a natural creep phenomenon will occur and the volume will shrink. The more impurities in the raw material, the more serious the above phenomenon. Therefore, for industrial furnaces with a long-term use temperature above 1000°C, high-purity natural fuel, high-alumina materials, and artificially synthesized silicic acid refractory fibers should be selected to ensure the stability of the industrial furnace structure.

The corrosion resistance of aluminum silicate refractory fiber cotton

Aluminosilicate refractory fiber is more resistant to chemical attack than glass fiber and mineral wool. It does not interact with acid at room temperature and does not infiltrate liquid metals and alloys at high temperatures. However, aluminum silicate refractory fibers are used in heat treatment furnaces with high concentrations of hydrogen, and if they contain a small amount of impurities, they are easily reduced. Raise the dew point in the furnace and intensify the oxidation of metal materials. In addition, when the temperature is higher than 1300°C, the refractory fiber will also chemically react with iron to form a silicic acid alloy.

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