When we go to choose ceramic fiber products, we will understand some data of the product and check the relevant inspection reports. Among them, the content of slag balls plays a great role in the use of ceramic fiber products, but what exactly are slag balls?
PART1 What are slag balls
In the process of spinning ceramic fibers into fibers, the vigilant particles that are not fibrillated are called shot. Generally speaking, those with particle size >0.212mm and bulk density of 2800-3200kg/m3 will be classified as slag balls.
Judging from the current ceramic fiber production process, slag balls of ceramic fiber products are inevitable. As long as the content of slag balls does not exceed the standard, the thermal conductivity of ceramic fiber products in the thermal insulation layer of industrial kiln linings has already taken the influence of slag balls into account. Therefore, there is no need to worry too much about the impact of slag balls on thermal insulation performance.
PART2 Slag ball content standard
The national standard stipulates that the content of slag balls in ceramic fiber blankets with a temperature resistance level below 1000°C is ≤25%, the content of slag balls in ceramic fiber blankets with a temperature resistance grade below 1450°C is ≤20%, and the content of slag balls in ceramic fiber products below 1700°C is ≤5 %, foreign countries control the content of slag balls with a particle size > 0.25mm to ≤5%, while domestically, due to the limitation of fiber manufacturing technology, the content of slag balls is controlled to ≤15%, that is, nearly 1/8 of fiber products are slag balls. It is twice as high as that of foreign countries. Therefore, when determining the bulk density of ceramic fiber products, the content of slag balls should be fully considered.
SUNTHERM's ceramic fiber products control the content of slag balls with a temperature resistance level of 1450 ℃ below 7% through advanced technology. The surface is clean and white, and the content of slag ball is low.
PART3 Influence of slag content on ceramic fiber products
The quality of ceramic fiber products is mainly judged from chemical composition, fiber diameter, fiber length, shot content, heating wire shrinkage and thermal conductivity, among which shot content is an important performance index.
a. Reduce the thermal insulation performance of the ceramic fiber module;
The high content of slag balls means that there are many lens particles in the ceramic fiber module, which leads to the deterioration of the structure of the fiber cotton, the enlargement of the cavity, the increase of the convective heat transfer of the air, and the increase of the total thermal conductivity and the decrease of the thermal insulation performance.
b. Reduce the strength of the ceramic fiber module;
The existence of slag balls changes the original arrangement of fiber cotton, making the gap between them larger, reducing the strength of the ceramic fiber module, and the wear resistance and electrical insulation of the product will become worse.
c. The energy saving effect is poor, which damages the interests of users;
Excessive content of slag balls will reduce the comprehensive energy-saving performance of ceramic fiber products, increase internal combustion consumption, and damage the interests of users.
