Necessity of Induction Heating in High Temperature Carbonization and High Temperature Graphitization Equipment of Carbon Fiber
Oct 18,2024
Enray
With the rapid increase of social demand for carbon fiber, the current production and preparation capacity of carbon fiber can not keep up with the development, only rely on the expansion of production to solve this problem.
Most of the existing production equipment uses resistance heating, especially the production line of 100 tons and above. From the perspective of equipment, the resistance heating method has low thermal efficiency, uneven heating, and unstable product performance, so that the production cost of carbon fiber is greatly increased.
There are very few using medium frequency induction heating, there is also the problem of high energy consumption.
In order to solve the above problems, we must start from the production process and equipment, and only discuss it from the perspective of equipment.
First, the induction heating method is used, and then a reasonable working frequency is selected.
Everyone knows that energy consumption is one of the most important factors that directly affect the cost of carbon fiber production, how to reduce energy consumption? It is difficult to achieve in the existing heating method, only to replace the existing heating method, in order to truly achieve the purpose of reducing energy consumption.
The induction heating method has the characteristics of uniform heating, fast heating and cooling speed, etc.; the induction heating method can greatly improve the temperature uniformity of the equipment, especially suitable for large carbon fiberhigh temperature carbonizationand high temperature graphitization production line. According to the characteristics of induction heating can quickly heat up and cool down without adverse effects on the equipment, the process of starting and stopping the furnace by resistance heating can be omitted, which greatly reduces energy consumption and saves energy. First of all, a large part of energy consumption can be reduced from the process.
Due to the different processes of various manufacturers, the energy savings are also different, but the use of induction heating and choose a reasonable working frequency for continuous high-temperature carbonization of carbon fiber andgraphitizationThe process can reduce energy consumption by 40% to 60%.
At present, the frequency is 1KHz or 2.5KHz, its energy saving effect is not very obvious, according to the principle of induction heating and the strength of the equipment, it is reasonable to choose a working frequency of 20KHz or higher. Its energy consumption is reduced by more than 50% compared to 2.5KHz, which is very objective and of great significance to the development of carbon fiber in China.
The following from the point of view of the heating body on the heating performance and energy consumption and energy saving.
At present, most of the carbon fiber continuous high-temperature carbonization and graphitization equipment uses graphite heating body, and the use of graphite heating body has certain limitations, mainly in terms of the volume size of the heating body, the length, width and height are limited by the graphite blank; If the carbon/carbon composite material is used as the heating body, the problem of limited volume size of the heating body can be well solved.
After the carbon/carbon composite heating element is used, a problem arises, that is, the problem of heating efficiency. At present, the induction heating method is mostly medium frequency induction heating, and its frequency is mostly 1KHz or 2.5KHz. With the increase of the power required by the equipment, the working frequency will gradually decrease. In order to achieve a certain efficiency under this parameter, it is required that the thickness of the heating body must be increased, and the energy consumption also increases accordingly. From the economic point of view, the use of carbon/carbon composite heating element, the general thickness of 8mm to 10mm (graphite heating element can also be processed to this thickness), if the traditional 1KHz or 2.5KHz medium frequency induction heating is very unreasonable, it is necessary to improve the heating frequency to achieve the purpose of improving heating efficiency. This also coincides with the aforementioned energy-saving measures.
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