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Relationship between density and energy efficiency of ceramic fiber blanket
10/9/2019

Relationship between density and energy efficiency of ceramic fiber blanket

Ceramic fiber blanket is a lightweight refractory insulation material. The reason why it is fire resistant depends on its chemical properties.

The reason why it is insulated is due to its physical properties. The main material of the ceramic fiber blanket is alumina and silica. After being melted at a high temperature, it is twisted/sprayed into fiber cotton, which is woven into a blanket by needle punching.

The volume is fluffy, and the material has low thermal conductivity, which can effectively block the heat circulation of the air, thereby achieving the effect of heat insulation. Ceramic fiber blankets generally have two densities of 96 kg/m3 and 128 kg/m3. Customers who often have industrial furnaces ask, is the density of the larger insulation effect or the low density?

      Speaking of this, we must mention heat transfer.

     Heat transfer is a natural phenomenon that is ubiquitous in nature. As long as there is a temperature difference between objects or between different parts of the same object, heat transfer will occur and will continue until the temperature is the same.

The only condition for heat transfer is that there is a temperature difference, which is independent of the state of the object and whether the object is in contact with each other. The result of the heat transfer is that the temperature difference disappears, that is, the heat transfer between the objects or different parts of the object reaches the same temperature.

As we all know, there are three ways to transfer heat: conduction, convection, and heat radiation.

1) Heat transfer can occur in gaseous, liquid, and solid materials, but the mechanism of heat transfer is different. The heat transfer of the gas is the result of collisions between the gas molecules as they move irregularly.

The kinetic energy of a gas molecule is related to its temperature. The molecules in the high temperature zone have a large kinetic energy, that is, a large velocity. When they move to a low temperature zone, they collide with molecules in the low temperature zone, and as a result, heat is transferred from the high temperature zone to the low temperature. Area.

Solids transfer heat in two ways: lattice vibration and migration of free electrons. In a non-conductive solid, energy is mainly transmitted by vibration of molecules and atoms near the equilibrium position of the crystal structure.

      2) Thermal convection refers to the way in which heat transfer occurs when the hot and cold fluids are mixed with each other due to the macroscopic motion of the fluid. This heat transfer occurs only in liquids and gases.

Since the molecules in the fluid undergo irregular thermal motion at the same time, convection is necessarily accompanied by heat conduction.

      3) The way in which an object transmits energy through electromagnetic waves is called radiation. There are many types of radiation, and the phenomenon that radiant energy is emitted due to heat is called thermal radiation.

      If you want to know which density of products you use to achieve better insulation, you should first understand the heat transfer method in the furnace environment, so that you can choose the material according to the furnace.