Glass tempering furnaces are classified into batch type and continuous type, hanging type and horizontal type, electric heating and gas heating. The glass tempering furnace needs insulation materials for furnace lining insulation, mainly using aluminum silicate ceramic fiber cotton.
To heat the glass tempering furnace, first understand the working principle of the glass tempering furnace. Glass tempering treatment usually uses physical methods to heat the glass to 650°C, which is the softening point of the glass. After the temperature is reached, it is blown and quenched to form a compressive stress layer on the surface of the glass and a tensile stress layer inside. When the glass is subjected to external force , The compressive stress layer can offset part of the tensile stress, avoid glass breakage, so as to achieve the purpose of improving the strength of the glass.
Generally, the temperature in the hearth of the glass tempering furnace is 800°C. The inside is heated by resistance wire. Aluminum silicate fiber material is more than enough for heat preservation at 800°C. For glass heated to the melting point for heat treatment, in order to prevent glass from being contaminated, aluminum silicate ceramic fiber blankets or ceramic fiber modules are not used for heat preservation.
The current glass tempered furnace lining generally adopts a standard ceramic fiber board layer structure for the roof, furnace wall, and furnace bottom. The total insulation thickness is 250mm. The roller way seals and heat insulation blocks and heat insulation special-shaped parts are made of high quality. Ceramic fiber cotton is used as raw material and is made by vacuum forming process. During the heating process, there is a temperature difference between the side and the middle of the furnace, which leads to uneven stress. There is currently no way to completely avoid stress, but a well-designed tempering equipment can minimize the visibility of stress spots. Ceramic fiber board, light weight, easy to install, low thermal conductivity, good thermal insulation effect, minimizes the visibility of stress spots, and improves the qualification rate of tempered glass products.
