Thermal conductivity is a physical indicator that characterizes the thermal conductivity of high-quality silica bricks in glass kilns, and its value is equal to the heat flux divided by the negative temperature gradient. Today, Luoyang Mele Xiaobian wants to introduce to you the heat capacity and conductivity of refractory materials. Let's learn about it together!
Heat capacity
Any substance heats up when heated, but different substances of the same mass require different amounts of heat to heat up 1°C. It is usually expressed by the heat (kJ) required to heat 1 kg of material under normal pressure to raise the temperature by 1 °C, which is called heat capacity (also called specific heat capacity).
temperature conductivity
Temperature conductivity is the speed of temperature transfer when the object is heated, which determines the size of the internal temperature gradient when the silica brick is rapidly cooled and heated. Thermal conductivity is expressed by thermal conductivity (α):
α=λ/cρ
In the formula:
λ——thermal conductivity of refractory material, w/m.k;
c——Isobaric heat capacity of refractory material, kJ/kg.℃;
ρ——bulk density of refractory, kg/m3.
Generally, the heat capacity of silica bricks is not very different, and their temperature conductivity mainly depends on the thermal conductivity and bulk density of the product.
Conductivity
Calcium-free silica bricks are poor conductors of electricity at room temperature. As temperature increases, resistance decreases and conductivity increases. The increase is particularly significant when the temperature is above 1000°C. For example, when heated to a molten state, it will show a great electrical conductivity.
