Working Principle And Usage Precautions of Glass Tempering Furnace

Tempered glass is currently widely used due to its high safety and 3-5 times higher impact resistance than ordinary glass. The glass tempering furnace is an industrial heating equipment for glass tempering, which can be divided into two types based on the different processing techniques of tempered glass: physical tempering and chemical tempering. Let's learn about the working principles of glass tempering furnaces together.

1. Working principle of glass tempering furnace

1.1. Physical methods

Physical tempering, also known as quenching tempering. Glass tempering equipment uses the technology of heating and then rapidly cooling flat glass to form compressive stress on the surface of the cooled glass and tensile stress inside the glass, thereby improving the strength of the glass and making ordinary annealed glass a tempered glass equipment. Due to the fact that this tempering method does not change the chemical composition of glass, it is called a physical method glass tempering equipment. The methods can be divided into the following types according to different media:

1.1.1. Gas medium tempering method: The so-called gas medium generally uses air as the heat transfer medium, and in this case, the tempering furnace needs to reach a temperature of 600-700 ℃. Then cool the glass by blowing in air. Although this cooling method greatly reduces cooling costs, the cooling speed is slow, the cooling efficiency is low, and it is easy to cause glass deformation.

1.1.2. Liquid medium tempering method: As the name suggests, liquid medium tempering method is the use of liquid to temper and cool heated glass.

1.1.3. Particle tempering method: using smaller alumina particles to cool the heated and softened glass particles. The cooling effect of this method is very good, and the quality of glass tempering is high, but the relative cost is also high.

The physical tempering method is currently a popular processing method among major enterprises in the market. Our Yuegao Glass Technology Co., Ltd. mainly utilizes the physical tempering method in the production of combination tempering equipment, flat tempering equipment, bent tempered glass equipment, continuous tempering equipment, and bidirectional tempering furnace equipment. Of course, the working principle of a glass tempering furnace includes not only physical methods but also chemical methods. Let's take a look together.

1.2. Chemical methods

Chemical tempering equipment improves the strength and mechanical properties of glass by changing the chemical composition of the glass surface. Due to the fact that this tempering method changes the chemical composition of glass, it is called a chemical method glass tempering equipment. The tempered glass produced by this method is less prone to deformation and has better quality. But the efficiency is low and the cost is high. The current methods of chemical tempering include surface dealkalization; Coating glass with low coefficient of thermal expansion, alkali metal ion exchange and other methods; Alkali metal ion exchange can be divided into high-temperature ion exchange and low-temperature ion exchange.

1.2.1. Ion exchange chemical tempering method: Glass is immersed in high-temperature molten salt, and the alkali ions in the glass and molten salt undergo ion exchange due to mutual diffusion, resulting in increased strength due to compressive stress in the exchange layer.

1.2.2. Surface dealkalization method: In a high-temperature atmosphere containing sulfite gas and water, the dealkalization method uses Pt catalyst to treat glass, allowing Na+ions to seep out from the surface of the glass and react with sulfite, resulting in a SiO2 rich layer on the surface. As a result, due to the low expansion of the surface, a compressive stress layer is formed on the surface during cooling.

2. Structure of Glass Tempering Furnace

The glass tempering furnace is divided into flat tempering furnace unit, bending tempering furnace unit, flat bending combined tempering furnace unit, and fixed mold tempering furnace unit according to the processing status of glass. The glass tempering unit is mainly composed of four parts: discharge section, convection heating section, flat tempering section, and extraction section, as well as various electrical components inside the high-pressure centrifugal fan, air supply pipeline, air collection box, air circuit, electrical control cabinet, operation console, frequency converter, PLC, encoder, and electrical control cabinet.

3. Precautions for using glass tempering furnace

3.1. When adjusting the chains, sprockets, gears, and other parts of the glass tempering furnace, the vehicle must be parked before operation. It is prohibited to operate by hand when the above components are in a different state to prevent accidents from occurring.

3.2. Due to sudden power outages, machine crashes, or cracking of the main drive chain, if the main drive stops running, it is necessary to manually rotate the glass inside the furnace to prevent damage to the ceramic rollers.

3.3. When the glass tempering furnace is in the production insulation state, a dedicated person is on duty and checks every half hour. When lifting the furnace body and wiping the ceramic roller conveyor, it is necessary to ensure that the inserted safety pin is properly secured before entering the furnace for work.

3.4. Before heating up the glass tempering furnace, it is necessary to check the electric furnace wires and related components of the furnace. Only after confirming that there are no errors can the furnace be heated up. During the heating process, there is someone on duty to supervise.

3.5. The scale of the glass to be processed in the furnace should be suitable for the processing ability of the tempering furnace. It is prohibited to be too large or too small to prevent damage to the glass tempering furnace. When adjusting the curvature of the glass tempering furnace, a dedicated person should command and operate it to prevent accidental operation and personnel damage.

The above is all the content introduced by the glass tempering furnace manufacturer about the working principle, structure, and usage precautions of the glass tempering furnace. We hope it can help everyone have a better understanding and knowledge of the tempering furnace. In addition, our company produces glass tempering furnaces with various structures and functions, which can meet various types of glass such as float glass, embossed glass, and hardness film glass. If you need, please feel free to call us for consultation.