Lightweight refractory material is also known as heat insulation refractories and insulation refractories, refer to the high porosity, small volume density, low thermal conductivity, has the thermal insulation performance of refractory materials. It includes insulating refractory products, refractory fiber and refractory fiber products.
As a kind of refractory material, lightweight refractory has a certain high temperature mechanical properties and good volume stability, is all sorts of high-temperature thermal equipment necessary. Compared with dense refractory material, the lightweight refractory filled with gas shows high apparent porosity, small volume density, good insulation performance, has the screened effect on heat. Therefore, the main characteristics of lightweight refractory material are:
1。High apparent porosity
A main performance index to measure lightweight refractory material quality is the porosity. Pore is made of the pore in the refractory raw materials and intergranular porosity after forming.
2. Small volume density
The volume density of lightweight refractory is small, no more than 1.3g/cm³. At present, volume density of common lightweight refractory industry is 0.5~1.0g/cm³ in industry.
3. Low thermal conductivity
Under unit the temperature gradient, within the unit time through unit vertical heat. It is the important performance index of lightweight refractory material quality, is also the important index of the design of thermal performance design. It indirectly reflects apparent porosity and bulk density of the products.
4. Low compression strength
Lightweight refractory material, due to large apparent porosity, low bulk density, not form a compact connection between crystals. So relative to the dense refractory material, its pressure strength is low, wear-resisting performance is poor.
Lightweight refractory material is important component part of kiln, boiler, the thermal container and other equipment, is widely used in industry. Because of the lightweight refractory material's high apparent porosity, occupies the irreplaceable position in the high efficiency and energy saving, reducing heat loss. So far, lightweight refractory material is the more used in insulation layer of the high temperature equipment.