The service temperature of heat-insulating firebrick
Light insulation brick is a kind of insulation material, which can reduce the heat, energy consumption, quality and comprehensive cost of the kiln body. The main properties of lightweight thermal insulation refractories include bulk density, porosity, thermal conductivity, service temperature and mechanical strength. Not many insulation materials can meet various performance requirements.
The wear resistance of firebrick is related to temperature
The wear resistance of firebrick is related to temperature. Some materials, such as silica-aluminum refractory bricks, are generally considered to be within a certain temperature range (for example, below 700 to 900 ° C). The higher the temperature, the lower the wear resistance. It can be considered that when the temperature rises, with the increase of the elastic modulus, the wear resistance of refractory bricks is even better than that of normal temperature at 1200~1350℃. When the temperature is higher than 1400℃, the viscosity of the liquid phase in the refractory brick decreases sharply. Some refractory bricks, such as chrome products, wear resistance decreases as the temperature increases. With the increase of elastic modulus, when the temperature increases to a certain extent, the wear performance increases with the decrease of elastic modulus. For example, the degree of aluminum silicate increases, and the wear resistance increases.
There are many kinds of lightweight heat-insulating firebricks, which can be classified according to different methods
(1) According to the use of temperature is divided into low temperature type less than 900℃), such as diatomite brick, perlite brick; Medium temperature type (1000~1200℃), such as vermiculite, calcium silicate, light clay brick, aluminum silicate fiber; High temperature type (>1200℃ above), such as light high aluminum bricks, alumina hollow balls, etc.
② According to the bulk density, it is divided into sub-light (1.00~1.39/cm3), light (0.4 ~1.og/cm3) and super light (0.49/cm3 or less).
According to the production method, it can be divided into adding combustible substances, foam method and chemical method.
④ According to the shape is divided into fiber, porous and granular.
⑤ According to the texture is divided into natural and artificial.
The temperature range and main characteristics of heat-insulating firebricks are as follows.
Diatomaceous earth brick is made of 900 natural porous raw materials, low thermal conductivity, good thermal insulation performance.
More than 900~1100 kinds of lightweight clay bricks are made of combustible materials.
Application introduction
Lightweight high aluminum brick 1100~1250 can directly contact the flame, widely used.
Cordierite brick 1300 has low thermal expansion and good spalling resistance.
Light corundum brick ≥1600 high alumina content, the main component is A-Al2O3, can be used for reducing atmosphere.
Light silicon brick 1220~1550 load softening point is high, good thermal stability.
The main component of calcium feldspar brick 1200~1300 is CaOAl2O3.2SiO2, which has small volume density and good crack resistance.
High temperature heat insulation of kiln adopts foam alumina brick 1350~i500 foam method.