Graphite heater

Introduction to the Core of the Graphite Heater

The graphite heater is a new type of heating equipment with high-purity graphite as its core heating element. It is manufactured through a combination of precise processing technology and electrical control technology. Its main function is to convert electrical energy into thermal energy, achieving precise temperature control and efficient heat transfer. The core material used is high-purity graphite (with a carbon content typically ≥ 99.9%), and some high-end products use isostatic pressed graphite. Through advanced molding and sintering processes, the internal structure of the material is ensured to be uniform, suitable for different heating requirements in various scenarios.

Compared with traditional metal heaters, the graphite heater breaks the limitation of "mainly standardized production", and can cover all specifications from mini models (minimum diameter ≤ 10mm) to super-large sizes (diameter ≥ 2 meters). It can not only meet the local temperature control requirements of laboratory precision research, but also adapt to the overall heating scenarios of large industrial equipment. Through customized design, it can match the individualized needs of different working conditions and different processes, truly achieving "customized as needed, precise adaptation".

Core performance advantages of the graphite heater

Excellent high-temperature resistance: The sublimation temperature of graphite can reach 3650℃, and the normal operating temperature can be maintained above 3000℃, far exceeding the temperature resistance limit of metal heaters. Moreover, its mechanical strength increases with the rise in temperature, reaching its peak around 1700℃, allowing for stable operation in high-temperature environments for a long time without any softening or deformation issues. It is suitable for ultra-high-temperature industrial scenarios.

High thermal and electrical conductivity: Graphite has excellent thermal and electrical conductivity. Its thermal conductivity is much higher than that of metals such as copper and iron, and it exhibits negative temperature coefficient resistance characteristics - the higher the temperature, the smaller the resistance, and the higher the electrical energy conversion efficiency. It can achieve rapid heating, and some products can have a heating rate of over 100℃/second. At the same time, it can ensure uniform heat conduction and reduce local temperature differences.

Excellent thermal shock resistance: The thermal expansion coefficient of graphite is extremely low. During heating and cooling processes, there will be no significant expansion or contraction, and it can withstand drastic temperature changes (with a temperature difference of up to 2000℃/min). It is not prone to cracking or damage, and its service life is much longer than that of traditional heaters, usually being 2-3 times that of similar metal heaters.

High chemical stability: In a vacuum or in an environment of inert gases (such as argon, nitrogen, etc.), graphite does not react with most acids, bases, or metal melts. It is corrosion-resistant and pollution-free, preventing the generation of impurities during heating and ensuring product purity. It is particularly suitable for precision manufacturing and high-purity material processing scenarios.

Key parameters: The core basis for selection

Heating power: The general range is 0.5kW - 100kW. It can be flexibly customized according to the heating area and heating requirements. At the same time, multiple power settings are supported, suitable for different heating needs in various working conditions. Temperature control range: Generally, it can cover from room temperature to 3000℃. In conventional industrial scenarios, the range is usually 200℃ - 1800℃. In special ultra-high temperature scenarios, it can reach above 3000℃ stably. Temperature control accuracy: It varies depending on the scenario. In precise scenarios (such as semiconductors, laboratories), it can reach ±0.1℃. In ordinary industrial scenarios, it is ±1℃, meeting the production and research requirements of different precision levels.

Core material: Mainly uses high-purity graphite (with a carbon content of ≥ 99.9%). Some high-end products use isostatic pressed graphite. Among them, isostatic pressed graphite is more suitable for higher precision and higher temperature usage scenarios, and the corresponding cost is also relatively higher. Size specifications: Diameter range is 10mm - 2000mm, length range is 50mm - 5000mm. At the same time, customizations of any size and shape are supported, covering mini, large-sized and irregular structures, and can match various furnace bodies and heating scenarios.

Surface load: The general range is 1 - 5 W/cm². It is recommended to control the actual usage within 1/2 - 1/3 of the maximum surface load to effectively extend the service life of the graphite heater; Power supply voltage: Commonly 220V/380V (AC). Special voltages can be customized according to power requirements, and it supports silicon-controlled rectifier voltage regulation, suitable for different power supply environments; Service life: General range is 1000 - 8000 hours. The specific lifespan depends on the usage temperature, working environment and daily maintenance conditions. The lifespan in high-temperature scenarios is relatively shorter.

Main application industries of graphite heaters

Semiconductor industry: As a core heating component, it is used in processes such as wafer manufacturing and chip packaging, enabling local precise temperature control (with temperature control accuracy within ±0.3℃), and electrode positioning accuracy reaching ±0.005mm. This helps improve the yield of 5nm chips and meets the high-precision requirements for processing micro-components.

Photovoltaic industry: Primarily used in single-crystal silicon growth furnaces and polycrystalline silicon ingot furnaces, it provides a uniform and stable thermal environment. Large-sized graphite heaters (with diameters up to over 1.8 meters) can enhance the uniformity of the thermal field to 98%, shorten the growth time of silicon rods in a single furnace, improve the conversion efficiency of photovoltaic silicon wafers, and promote the upgrading of photovoltaic industry production capacity.

Metallurgy and Vacuum Smelting Industry: For vacuum smelting of non-ferrous metals and special metals, it can stably heat in a vacuum or inert gas environment, avoiding metal oxidation and improving the purity of metal smelting. It is widely used in the preparation of aerospace materials and special alloys, and is also suitable for the heating requirements of continuous casting molds for ferrous metals.

Chemical industry: It is used in high-temperature chemical reaction vessels and catalyst preparation scenarios. With its corrosion-resistant and pollution-free characteristics, it can prevent reactions with chemical media during heating, ensuring product purity. At the same time, it is suitable for high-temperature and high-pressure chemical reaction environments.