Characteristics of silicon carbide heating elements
Silicon carbide heating elements are mainly made of high-purity green hexagonal silicon carbide. They are processed into blanks through specific material ratios and then undergo silicification, recrystallization and sintering at a high temperature of 2200℃. This complex manufacturing process endows silicon carbide heating elements with many excellent properties.
High-temperature resistance: It can withstand extremely high temperatures and operate stably in environments as high as 1500℃ or even higher, providing a reliable heat source guarantee for the high-temperature firing process in ceramic and glass production. During the high-temperature sintering process of ceramics, silicon carbide heating elements can continuously provide stable high temperatures, causing physical and chemical changes in the ceramic body, thereby achieving the desired texture and performance.
Oxidation resistance and corrosion resistance: It has excellent oxidation resistance and corrosion resistance. In high-temperature environments, a dense silicon dioxide protective film forms on its surface, effectively preventing further oxidation and extending its service life. Meanwhile, silicon carbide heating elements have strong acid resistance and a high tolerance for some acidic substances that may be produced during glass manufacturing, ensuring stable operation in complex production environments.
Rapid and stable heating: With a fast heating rate, it can reach the set temperature in a short time, improving production efficiency. Moreover, during operation, it can provide stable heat output. When used in conjunction with an automated electrical control system, it can precisely control the temperature, meeting the strict requirements for temperature accuracy in the production processes of ceramics and glass. During the melting process of glass, stable temperature control helps ensure the uniformity of the quality of the glass liquid.
Good chemical stability: Silicon carbide heating elements have excellent chemical stability. Under high-temperature conditions, except for alkaline substances which have a certain corrosive effect on them, they can maintain chemical inertness with most substances. This ensures that they will not cause contamination to products in the production of ceramics and glass, guaranteeing the purity and quality of the products
The application of silicon carbide heating elements in the glass field
Float glass production
in float glass production technology, silicon carbide heating elements play a crucial role. When the British Pilkington Company invented the float process, it adopted specific silicon carbide heating elements on the production line, successfully solving the key problem of glass forming at that time, thus giving birth to float glass. The glass liquid floats on the surface of the molten metal. Under the stable high-temperature environment provided by the silicon carbide heating element, it is polished and formed, producing flat glass with a smooth surface and no wavy ribs.
In 1971, when the former Ministry of Building Materials Industry independently developed China's float glass technology, glass technicians designed an electric heating device with silicon carbide heating elements on the upper part of the tin bath, effectively solving the problem of easy condensation and splashing of high-temperature glass liquid when passing through the tin bath. For example, the SD component in our factory's products adopts a float three-phase silicon carbide heating element with a unique glaze coating technology, which can meet the usage requirements of most flat glass, architectural glass, automotive glass, etc. It is widely used worldwide and has an expected service life of 10 years (varying depending on the usage conditions). Its HD components adopt reaction sintering process, featuring higher volume density and stronger bending strength. They can be applied at a tin bath temperature of 1300℃, meeting high-power demands without the need for coating protection. They are widely used in high-end glass production lines, such as ultra-thin electronic glass, high alumina cover glass, and high borosilicate glass, among other production fields.
Glass container production
in the process of glass container production, silicon carbide heating elements of the temperature control precision affects the quality of the product. Take a well-known glass container manufacturer as an example. In the feeding channel, silicon carbide heating elements are evenly arranged above the glass liquid. By using the downward radiation heating of the silicon carbide heating elements, the glass liquid is heated and the walls on both sides are heated. Five-section rods (double-heating element silicon carbide heating elements) specifically designed for the glass material channel industry are selected. This silicon carbide heating element is made by welding two identical heating elements and three cold ends through a special process. The middle part does not generate heat or generates little heat, while the part close to the side wall generates heat. Through reasonable design, it ensures that the temperature of the glass liquid drops uniformly during flow. For the temperature at the material basin, gun-shaped silicon carbide heating elements, three-section silicon carbide heating elements or channel-shaped silicon carbide heating elements are distributed around or evenly around the material basin for individual control to prevent abnormal temperature from affecting the shape of the material droplets, thereby ensuring the stable forming quality of the glass container.
Application cases of silicon carbide heating elements in ceramic production
Tile production
in ceramic tile ceramic tile production links, silicon carbide heating elements of efficient heating performance promoted the production efficiency. A large ceramic tile manufacturing enterprise has installed a large number of silicon carbide heating elements in its roller kiln. When the tile body moves rapidly in the roller kiln, the silicon carbide heating element heats up quickly, rapidly raising the temperature to the appropriate firing temperature, which is generally around 1200℃ - 1300℃. Throughout the entire firing process, the silicon carbide heating elements continuously provide a stable heat output. The green body is uniformly heated, and after a series of physical and chemical reactions, a beautiful and durable glaze surface is formed on the surface of the ceramic tiles. Due to the rapid and stable heating of silicon carbide heating elements, the production efficiency of ceramic tiles in this enterprise has been significantly improved. At the same time, the consistency of product quality is good and the rate of defective products has decreased.
Preparation of special Ceramic materials
Take the preparation of high-temperature ceramics as an example. When a certain research institution was developing a new type of high-temperature ceramic, it had extremely strict requirements for temperature control. They use silicon carbide heating elements as heating elements to precisely control the temperature within a specific range, generally between 1600℃ and 1800℃. In this high-temperature environment, the atoms in ceramic materials are arranged in an ordered manner, thereby obtaining ceramic products with excellent high-temperature performance. Through precise temperature control, this research institution has successfully enhanced the performance stability and yield of special ceramic materials. For instance, during the preparation process, through the precise temperature control of silicon carbide heating elements, the internal structural defects of ceramics caused by temperature fluctuations were effectively avoided, resulting in the high-temperature ceramics produced performing outstandingly in key performance indicators such as high-temperature strength and oxidation resistance
Advantages and Prospects of Silicon Carbide Heating Elements Application
Significant advantages: The use ofsilicon carbide heating elements has many advantages. It is not only convenient for installation and maintenance, but also, compared with traditional heating elements, can effectively reduce energy consumption, improve energy utilization efficiency, and save production costs for enterprises. Its long service life feature reduces the frequency of equipment maintenance and replacement, further enhancing the continuity and stability of production.
Future outlook
With the continuous development of the ceramic and glass industries, the requirements for production processes and product quality are also increasing day by day. Silicon carbide heating elements, as important heating elements, will continuously witness technological innovation and improvement. In the future, it is expected that by optimizing material formulas and manufacturing processes, the performance of silicon carbide heating elements can be further enhanced, such as raising their high-temperature resistance limits, strengthening their oxidation resistance and corrosion resistance, and improving the accuracy of temperature control, to better meet the growing production demands in the ceramic and glass industries and promote their development towards higher quality and greater efficiency.