What are the requirements for choosing refractory bricks for ceramic furnaces??

With the improvement of production technology, ceramic kilns have higher standards and requirements for refractory materials. Nowadays, ceramic kiln needs to maximize the life of the kiln and save energy, performing the function of firing ceramic products. Different parts of a ceramic kiln use different refractory materials. Refractory materials, used in ceramic kiln, can be divided into two categories: for heat preservation and thermal insulation.

What are the requirements for refractory materials in ceramic kilns??

Thermal conductivity of refractory bricks

The ceramic kiln uses refractory materials with low thermal conductivity, which allows to reduce the temperature of the furnace surface, reduce losses during heat removal and reduce the cost of ceramic production.

Flexural strength

The flexural strength of refractory bricks has a certain influence on the structural stability of ceramic kilns.. The high flexural strength of fire bricks can prolong the service life of the kiln and reduce the deformation and cracking of the kiln, caused by thermal expansion. Besides, fire brick with high bending strength can guarantee, that a ceramic stove will withstand higher loads.

Load softening temperature

Usually, The softening temperature of the material of the inner layer of a ceramic kiln should be 100-500°C higher than the normal operating temperature of the kiln, For example, When firing porcelain stoneware bricks, the softening temperature of the material in the inner layer of the firing zone must be above 1380°C. Otherwise, during operation of the kiln or during its ignition and firing due to, that the short-term temperature of the oven is higher than the temperature of long-term use, the furnace body will be deformed or even recessed and damaged.

Thermal shock resistance

Thermal shock resistance refers to the ability of refractory materials to withstand rapid temperature changes without damage. There are also certain requirements for the resistance of refractory bricks to thermal shock in ceramic kilns.
For a batch kiln, the kiln body must be heated from room temperature to the ceramic firing temperature for each operation, and then lowered to room temperature after standing for a period of time. Repeated heating and cooling in this way, if the resistance of the refractory material to thermal shock is low, fire brick cracks easily, peels off and flips over, which in severe cases will lead to destruction of the furnace body.