The refractory material for glass melting furnaces, in addition to our high temperature performance, is also very important at the time of purchase. The physical properties of the product are highly correlated with the actual life of the product. The specific items to be referred to are:
(1) Organizational structure
The refractory material is a heterogeneous body composed of a solid phase (including crystals and a glass phase) and pores. The macroscopic structural characteristics of the product are the main factors affecting its high temperature use properties.
1 porosity
In refractory materials, there are often many pores of different sizes and shapes. The open air holes (also called the air holes), which are interconnected, are called communicating air holes, and those that do not communicate with the atmosphere are called closed air holes. The porosity is usually used to reflect the degree of compaction of the refractory material, that is, the percentage of the pore volume in the brick to the total volume. Porosity is the basic technical indicator of refractory materials, which affects almost all properties of refractory products. The smaller the porosity, the better the erosion resistance of the refractory material and the higher the structural strength. The higher the porosity, the lower the thermal conductivity of the material.
2 bulk density
The bulk density is the mass of the refractory unit volume (the total volume including the pores). It intuitively reflects the compactness of refractory products and is an important indicator for measuring the quality level of refractory materials and dense refractory products. In general, the higher the bulk density, the smaller the porosity, and the better the series of properties such as strength and high temperature load softening temperature.
3 true density
True density refers to the ratio of the mass of a porous material to its true volume (excluding pores). True volume refers to the volume of solid material in a porous body. The value of the value is independent of the density and porosity, and is related to the chemical mineral composition of the refractory.
(2) Thermal properties
1 thermal expansion
When the refractory is heated, the property in which the volume expands with an increase in temperature is called thermal expansion. It is usually expressed by a coefficient of linear expansion or a coefficient of bulk expansion. When using refractory materials, it is necessary to attach great importance to its thermal expansion. In the structure of the furnace, expansion joints should be reserved according to the thermal expansion characteristics of the refractory materials. In the ignition kiln, a reasonable heating curve should be established according to the thermal expansion of the refractory materials. And the necessary measures such as adjusting the pull bar.
2 thermal conductivity
Thermal conductivity is the amount of thermal conductivity of a refractory material and is expressed in terms of thermal conductivity. The so-called thermal conductivity refers to the heat flow rate per unit area of the material under a unit temperature gradient. It depends mainly on the chemical composition and organization of the material.
3 heat capacity
Heat capacity, also known as specific heat capacity, refers to the heat required to heat 1kg of refractory material to raise temperature by 1 °C under normal pressure. It is of great significance in designing and controlling the heating and heat storage capacity of the melting furnace.
To purchase refractory materials for glass melting furnaces, Zhengzhou Sunrise Refractory Group can be selected. At present, domestic high-quality manufacturers can quickly complete order matching.
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