Shandong Zouyu has very strict control over the raw materials of ceramic fiber blankets. In the application of aluminum silicate fiber materials for many years, we often find that the actual temperature does not exceed the temperature range of the material, but the fiber materials have severe shrinkage and chalking.
After inspection, we found that the Al2O3 in the product meets the product requirements, while the SiO2 is low, and the impurities such as Fe2O3, CaO, MgO, Na2O, and K2O seriously exceed the standard.
These substances are low melting point oxides. Excessive low melting point oxides will reduce the eutectic melting point of aluminum silicate fiber materials. If the content of impurities other than Al2O3 and SiO2 reaches more than 3.5%, the ratio will be controlled within 1%, which will cause silicic acid. The actual use temperature of aluminum fiber material is reduced by nearly 100 ° C.
Therefore, when we select aluminum silicate fiber materials, we must not only check the composition of Al2O3, but also strictly control the content of other impurities.
Shandong Zou Yu does not have a one-sided pursuit of too low or too high bulk density. The aluminum silicate fiber itself is composed of Al2O3 and SiO2, and its heat capacity is basically the same as that of refractory brick products. However, fiber products such as felts and blankets use fiber interlacing methods. A hollow unit structure is formed, and the bulk capacity of the product is greatly reduced, which changes the thermal conductivity.
The thermal conductivity of fiber products with a bulk density of 150-250kg / m3 is about 20% of the thermal conductivity of heavy bricks with a bulk density of 2070Kg / m3; it is about 37-40% of the thermal conductivity of light bricks with a bulk density of 1300Kg / m3. The bulk density of fiber products is in the range of 150-250kg / m3. As the bulk density increases, the thermal conductivity gradually decreases, and its heat dissipation loss gradually decreases.
However, with the increase of the bulk density, the structural performance of the loose unit body also decreases. When the bulk weight is greater than 400kg / m3, the thermal conductivity will increase, and at the same time, the heat storage loss will increase, and the overall energy saving will decrease. When determining the bulk density of aluminum silicate fiber products, we must fully consider the amount of slag balls.
The slag ball content in the product is an important factor affecting the bulk density. The slag ball has a bulk density of 2800 ～ 3200kg / m3. Too much slag ball content in the fiber product will reduce the comprehensive energy saving performance and harm the interests of users. The content of slag balls with a particle size of more than 0.25mm is controlled to ≤5% in foreign countries, while the content of slag balls is controlled to ≤15% due to the limitation of fiber manufacturing technology in China. The content is doubled.
Shandong Zouyu International Trade Co., Ltd. adopts a new slag removal process to ensure that the content of slag balls is controlled at ≤10%, reaching the industry-leading level. Product quality is our lifeline, and ceramic fiber blankets must be well controlled by technology!