Common insulating refractory materials in glass kilns

Common insulating refractory materials in glass kilns

In the operation of glass kilns, insulating refractory materials play a vital role. They can not only effectively reduce heat loss and improve energy utilization efficiency, but also provide guarantee for the stable operation of the kiln and extend the service life of the kiln. The following will introduce the common insulating refractory materials in glass kilns in detail.

The importance of insulating refractory materials

Glass kilns need to consume a lot of energy to maintain a high temperature environment during the production process. The presence of insulating refractory materials can greatly prevent heat from being transferred from the inside of the kiln to the outside, reducing heat loss. This not only helps to save energy and reduce emissions, reduce production costs, but also makes the temperature distribution inside the kiln more uniform, and improves the quality and production efficiency of glass products. At the same time, good insulation effect can reduce the temperature of the outer wall of the kiln, improve the working environment, and ensure the safety of operators.

Common types of insulating refractory materials

Lightweight clay brick: This is a more traditional insulating refractory material. It uses clay as the main raw material, and after a special firing process, it forms many tiny pore structures inside, so that it has good thermal insulation properties. The advantages of lightweight clay bricks are relatively low price, convenient construction, and certain refractoriness, which can generally withstand high temperatures of 1200℃ – 1400℃. Lightweight clay bricks are often used as insulation materials in some non-critical parts of glass kilns, such as the outer layer of kiln walls.

High-alumina insulation bricks: High-alumina insulation bricks are made of high-alumina bauxite as the main raw material. Compared with lightweight clay bricks, it has higher refractoriness and better insulation performance, and can withstand high temperatures of 1500℃ – 1700℃. High-alumina insulation bricks also have good chemical stability and can resist a certain degree of high-temperature erosion. In the high-temperature area of ​​the glass kiln, such as the kiln roof, high-alumina insulation bricks are sometimes used to achieve the dual needs of insulation and fire resistance.

Alumina silicate fiber products: Alumina silicate fiber products include various forms such as aluminum silicate fiber blankets and aluminum silicate fiberboards. It is made of aluminum silicate fiber after processing, and has the characteristics of light weight, low thermal conductivity, and excellent insulation performance. Aluminum silicate fiber products have a wide range of operating temperatures, generally between 1000℃ – 1400℃. They are flexible and easy to construct, and can be cut and installed according to different kiln shapes. Aluminum silicate fiber products are widely used in the sealing parts of glass kilns, pipe insulation and other parts.

Foam ceramics: Foam ceramics are a new type of thermal insulation refractory material with a unique three-dimensional mesh porous structure. This structure gives foam ceramics extremely low density and excellent thermal insulation properties, as well as high strength and good chemical stability. Foam ceramics have a high refractoriness, which can reach more than 1600℃. In some special parts of glass kilns, such as areas that need to withstand high temperatures and have extremely high insulation requirements, foam ceramics can play their unique advantages.

Performance characteristics of thermal insulation refractory materials

Low thermal conductivity: This is a key performance indicator of thermal insulation refractory materials. Low thermal conductivity means that heat is transferred through the material at a slower rate, which can effectively prevent heat loss. Different types of insulating refractory materials have different thermal conductivity coefficients, but in general they are much lower than ordinary refractory materials.

Good refractory performance: Although the main function is heat insulation, insulating refractory materials also need to have a certain degree of refractoriness to ensure that they can be used stably in the high temperature environment of the glass kiln without softening, deformation or melting.

Low density: The density of most insulating refractory materials is relatively low, which not only helps to reduce the overall weight of the kiln and reduce the structural bearing requirements, but also improves the thermal insulation performance to a certain extent.

Thermal shock resistance: Glass kilns will experience temperature fluctuations during operation. Insulating refractory materials need to have good thermal shock resistance to prevent cracks or damage caused by temperature changes and ensure the stability of their thermal insulation performance.

Application parts of insulating refractory materials in glass kilns

Kiln roof: The kiln roof is one of the important parts of the glass kiln where heat is lost. Usually, a multi-layer insulation structure is used, such as the inner layer uses high-aluminum insulation bricks or other insulation materials with high refractoriness, and the outer layer is laid with materials such as aluminum silicate fiber blankets to achieve good insulation effect and protect the kiln roof structure from high temperature erosion.

Kiln wall: The kiln wall is generally divided into an inner layer and an outer layer. The inner layer uses refractory bricks to resist the erosion of glass liquid and high-temperature flames, and the outer layer uses lightweight clay bricks, aluminum silicate fiberboards and other insulation materials to reduce the transfer of heat to the outside of the kiln. In some large glass kilns, composite kiln walls are also used to further improve the insulation performance.

Flue: The exhaust gas temperature in the flue is high, and insulation treatment is required to reduce heat loss and prevent the temperature of the outer wall of the flue from being too high. Insulation bricks or aluminum silicate fiber products can be used to wrap the flue to achieve the purpose of insulation.

Pipeline: Various pipelines in the glass kiln, such as fuel delivery pipelines, air pipelines, etc., also need to be insulated. Materials such as aluminum silicate fiber tube shell are commonly used pipe insulation materials, which can effectively reduce the heat loss of the medium in the pipe and improve energy utilization efficiency.

Advantages of thermal insulation refractory materials

Significant energy-saving effect: By effectively reducing heat loss, thermal insulation refractory materials can help glass kilns save a lot of energy, reduce production costs, and improve the economic benefits of enterprises.

Improve production efficiency: A stable kiln temperature environment is conducive to the melting and forming process of glass, reduces fluctuations in the production process, and improves product quality and production efficiency.

Extend the service life of the kiln: Good thermal insulation performance can reduce the temperature of the kiln structural materials, reduce the thermal stress and chemical erosion it is subjected to, thereby extending the overall service life of the kiln and reducing maintenance and replacement costs.

Development trend

Research and development of high-performance materials: With the continuous development of glass kiln technology, the performance requirements for thermal insulation refractory materials are also getting higher and higher. In the future, we will focus on the research and development of new thermal insulation refractory materials with lower thermal conductivity, higher refractoriness and better thermal shock resistance.

Application of environmentally friendly materials: In the context of increasingly stringent environmental protection requirements, the production and use of thermal insulation refractory materials will pay more attention to environmental protection. Researchers will look for more environmentally friendly raw materials and production processes to reduce environmental pollution.

Composite and multifunctional: In order to meet the complex needs of different parts of glass kilns, thermal insulation and refractory materials will develop in the direction of composite and multifunctional. For example, multiple properties such as thermal insulation, fire resistance, and corrosion resistance are integrated to develop materials with better comprehensive performance.

In short, thermal insulation and refractory materials play an indispensable role in glass kilns. With the continuous advancement and innovation of technology, they will play a more important role in the development of the glass industry and provide strong support for promoting the sustainable development of the glass industry.