The performance of insulating refractory bricks

The performance of insulating refractory bricks

Performance

1. Low thermal conductivity: The most outstanding performance of insulating refractory bricks is their very low thermal conductivity, which is usually between 0.2 – 1.0 W/(m・K), much lower than that of general dense refractory materials. This is due to its unique porous structure, with a large number of tiny pores inside, where air is trapped. Since the thermal conductivity of air is extremely poor, it effectively prevents the rapid transfer of heat, thus achieving a good thermal insulation effect.
2. Lightweight characteristics: Its volume density is relatively small, generally in the range of 0.8-1.5 g/cm³. This allows the insulating refractory bricks to significantly reduce the deadweight load of thermal equipment such as furnaces and kilns during use, reduce the cost of the equipment’s supporting structure, and also meet the needs of some industrial scenarios with strict weight restrictions, such as high-temperature test equipment in the aerospace field.
3.  Certain refractory performance: Although not as high as high-temperature refractory materials such as magnesia-chrome bricks, thermal insulation refractory bricks also have certain refractory capabilities, and the general refractory can reach 1000℃ – 1600℃. Its raw materials contain refractory clay, diatomaceous earth, siliceous materials, etc. These ingredients can form a relatively stable structure at high temperatures, maintain the basic shape of the brick body, and ensure that the insulation effect is played within the corresponding working temperature range.
4. Good thermal stability: Since the internal pore structure can buffer the stress caused by thermal expansion and contraction, the insulating refractory bricks have good thermal stability and can work normally in a temperature change environment with a certain frequency. For example, in an intermittently operated industrial kiln, it can withstand multiple heating and cooling cycles without being quickly damaged by thermal shock, thus extending its service life.

Functions

1. Energy saving and consumption reduction: In industrial kilns, heating furnaces and other equipment, a large amount of heat will be lost to the surrounding environment through the furnace lining. Insulating refractory bricks, as lining materials, can effectively block heat transfer to the outside, reduce heat loss, reduce fuel consumption, and improve energy efficiency. According to statistics, the rational use of insulating refractory bricks can increase the thermal efficiency of industrial furnaces by 10% – 30%. For large industrial furnaces that run continuously for a long time, the energy saving effect is significant.
2. Improve the working environment temperature: In addition to reducing energy waste, insulating refractory bricks can also reduce the surface temperature of the furnace, prevent surrounding workers from being baked by high temperatures, and improve working conditions. For example, around the melting furnace in the foundry, after using insulating refractory bricks, the temperature of the furnace shell is greatly reduced, reducing the heat radiation in the workshop, making the operator feel more comfortable, and also helping to reduce the ventilation and heat dissipation costs of the workshop.
3. Protect equipment structure: Its thermal insulation performance indirectly protects the metal shell and supporting structure of the furnace body, preventing the metal strength from decreasing, deformation or even damage due to long-term heating. In some high-temperature and high-pressure chemical reactors, thermal insulation refractory bricks can keep the furnace shell temperature at a low level, ensure the mechanical properties and safety of the equipment, extend the overall service life of the equipment, and reduce equipment maintenance costs.

In summary, thermal insulation refractory bricks play an important role in many aspects such as industrial production, energy utilization and labor protection due to their unique properties.