What are the types of insulation and refractory materials? - Detailed explanation of Henan refractory bricks
What are the types of thermal insulation and refractory materials - detailed explanation of Henan refractory bricks. It is not difficult for us to understand the name of thermal insulation refractory bricks, which mainly play a role in thermal insulation. So what are the characteristics and types of commonly used insulation and refractory materials?
1、 Structural characteristics of thermal insulation refractory materials
In terms of organizational structure, compared with ordinary dense refractory materials, the most significant characteristics of insulation refractory materials are high porosity and large pore size. In most fully sintered refractory products, the porosity is generally less than 20%, and the pore size is relatively small, such as the pore size of clay bricks, which is generally 2-60 μ m. 19-21 for silica bricks μ m. Magnesium bricks are 26-28 μ M. However, the porosity of various lightweight thermal insulation refractory materials is generally more than 45%, and the pore diameter of the pore is large. For example, the pore diameter of the lightweight brick produced by adding combustible materials is 0.1~1mm, the pore diameter of the lightweight alumina products produced by the foam method is 0.1~0.5mm, and the pore diameter of the lightweight alumina hollow ball products is 0.5~5mm. When observed under a microscope, regardless of the chemical mineral composition of the solid phase in the material, the organizational structure of insulation refractory materials can be clearly divided into three types:
(1) Gas phase connected structure or open pore structure. The microstructure characteristic of this type of lightweight thermal insulation refractory material is that the solid phase is separated by the gas phase, becoming discontinuous and discontinuous phases. On the contrary, due to the dominance of open pores in the structure, the pores are interconnected and form a gas phase continuous structure. The insulation refractory layer filled with lightweight refractory powder particles, and most lightweight insulation refractory materials produced by the combustible addition method, belong to this structural type.
(2) Solid phase connection structure or closed pore structure. The microstructure characteristic of this type of lightweight thermal insulation refractory material is that most of the pores exist in the form of closed pores. The gas phase is surrounded by a continuous solid phase, forming a structural feature where the solid phase is continuous while the gas phase is separated and isolated. In other words, in this structure, the continuous phase is a solid phase and the gas phase is a discontinuous phase. Light refractory products produced by foam method and various oxide hollow ball heat insulation products belong to this structure type. In this structure, solid substances exist in the form of fiber to form a continuous solid skeleton, while gas phase continuously exists in the framework gap of fiber materials.
2、 Types of insulation and refractory materials
Insulating refractory materials refer to materials with high porosity, small bulk density, thermal insulation properties, and the ability to shield against heat. Due to the lightweight nature of insulation refractory materials, they are commonly referred to as lightweight refractory materials. Insulating refractory materials are not only mainly used to prevent the loss of heat outflow under conditions above ambient temperature, but also used to prevent the inflow of heat under conditions below ambient temperature. When used in the former case, it is often referred to as insulation material; In the latter case, it is called a cold insulation material. Due to the requirements of energy-saving work, the development of insulation and refractory materials is very rapid, with a wide variety of types that can be classified from different perspectives.
The most commonly used classification method is based on the chemical mineral composition of the material or the raw materials used in production