Self-circulation waste heat recovery device for graphite electrode production

Abstract

The invention discloses a self-circulation waste heat recovery device for graphite electrode production, which comprises a closed container, a cooling system and a heat exchange device, and the closed container is filled with a phase change material; the phase change material is a high-temperature metal alloy or inorganic salt material with a melting point of 600-1000 DEG C; the closed container is made of a high-temperature-resistant alloy, and the closed container is made of a tungsten-based alloy, a tantalum-based alloy, a rhenium-based alloy or a molybdenum-based alloy. According to the self-circulation waste heat recovery device for graphite electrode production, waste heat of a graphitization kiln can be efficiently recovered, energy waste is reduced, the cooling time is shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to a self - circulating waste heat recovery device, and more particularly to a self - circulating waste heat recovery device for the production of graphite electrodes. Background Art

[0002] The graphitization kiln is an indispensable device in the production of graphite electrodes. During its production process, the temperature inside the kiln can reach 3000°C. The traditional cooling method mainly relies on natural cooling, which is not only inefficient but also causes a large amount of high - temperature heat energy to be wasted during the cooling process. In order to improve energy utilization efficiency and reduce the cooling time, it is necessary to provide a self - circulating waste heat recovery device for the production of graphite electrodes. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a self - circulating waste heat recovery device for the production of graphite electrodes, which can efficiently recover the waste heat of the graphitization kiln, reduce energy waste, shorten the cooling time, and improve production efficiency.

[0004] The technical solution adopted by the present invention to solve the above - mentioned technical problem is to provide a self - circulating waste heat recovery device for the production of graphite electrodes, which includes a closed container, a cooling system, and a heat exchange device, and a phase - change material is filled in the closed container.

[0005] Further, the phase - change material is a high - temperature metal alloy or inorganic salt material with a melting point between 600°C and 1000°C.

[0006] Further, the high - temperature metal alloy is sodium - potassium alloy, magnesium - aluminum alloy or copper - aluminum alloy.

[0007] Further, the inorganic salts are lithium carbonate, calcium chloride or potassium nitrate.

[0008] Further, the closed container is made of a high - temperature - resistant alloy, and the material of the closed container is tungsten - based alloy, tantalum - based alloy, rhenium - based alloy or molybdenum - based alloy.

[0009] Further, the closed container includes a tube shell and an end cap that are hermetically connected. A phase - change material is provided as a working medium inside the tube shell; the area of the tube shell in contact with the hot fluid is the evaporation section, and the area of the tube shell in contact with the cold fluid is the condensation section; an adiabatic section is provided between the evaporation section and the condensation section.

[0010] Further, the outside of the closed container is coated with a heat - insulating layer.

[0011] Further, the number of the closed containers is multiple, which are arranged in an equidistant array and are attached to the graphite heat - insulating layer of the graphitization kiln.

[0012] Furthermore, the heat exchange device further includes a thermal energy storage unit for storing and retaining the recovered heat.

[0013] The present invention has the following beneficial effects compared with the prior art: The self-circulating waste heat recovery device for graphite electrode production provided by the present invention, through the efficient heat storage and release characteristics of the phase change material, effectively stores the released high-temperature heat during the cooling process of the graphitization furnace, and recycles it under appropriate conditions for other industrial processes or energy reuse, thereby reducing energy waste, shortening the cooling time, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of the self-circulating waste heat recovery device for graphite electrode production of the present invention; Figure 2 is a schematic diagram of the heat exchange of the phase change material in the closed container of the self-circulating waste heat recovery device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The present invention will be further described below in conjunction with the drawings and embodiments.

[0016] Please refer to Figure 1 and Figure 2 , the self-circulating waste heat recovery device for graphite electrode production provided by the present invention mainly consists of the following parts: (1) High-temperature resistant closed container: The closed container 2 is made of high-temperature resistant alloy and can withstand an environmental temperature of up to 3000 °C, such as tungsten-based alloy, tantalum-based alloy, rhenium-based alloy, molybdenum-based alloy, etc. The container is filled with a phase change material suitable for heat storage under high-temperature conditions. The outside of the container is coated with highly efficient thermal insulation material to ensure the minimum heat loss during storage.

[0017] (2) Phase change material: The phase change material is a high-temperature metal alloy (such as sodium-potassium alloy, magnesium-aluminum alloy, and copper-aluminum alloy, etc.) or inorganic salt material (such as lithium carbonate, calcium chloride, and potassium nitrate, etc.), and the melting point is between 600 °C and 1000 °C. When the temperature of the graphitization furnace reaches or exceeds the melting point of the phase change material, the material changes from solid state to liquid state, absorbing and storing a large amount of heat.

[0018] (3) Cooling system: The cooling system 3 is used to cool the container during the cooling stage, causing the liquid phase change material to solidify back into a solid state and release the stored heat. The cooling system 3 includes an automatic control device that can precisely adjust the cooling rate to ensure a stable release of heat. Preferably, the cooling rate is between 30 - 60 °C / h. If the cooling rate is too high, the subsequent temperature difference becomes smaller, and the cooling speed suddenly decreases, prolonging the overall cooling duration. If the cooling rate is too low, the effect is limited. The cooling system 3 can be an air cooling system, a liquid cooling system, or a hybrid cooling system that combines multiple cooling methods to achieve efficient heat release and control.

[0019] (4) Heat exchange device: The heat exchange device 1 is used to transfer the released heat to other processes that require thermal energy, such as preheating the feed of a graphitization furnace, supplying other equipment, or generating electricity. The heat exchange device 1 is designed with a structure having high thermal conductivity to maximize the utilization of the released heat.

[0020] (5) Thermal energy storage unit (optional): A thermal energy storage unit can also be designed in the heat exchange device to store and retain the recovered heat when the heat is not immediately needed for subsequent use. With this design, the flexibility and adaptability of the device are greatly enhanced.

[0021] By adopting the above technical solutions, a self - circulating waste heat recovery device for graphite electrode production in the present invention forms a self - circulating and efficient system during the waste heat recovery process of the graphitization furnace. It not only significantly improves the energy utilization efficiency, but also shortens the cooling time of the furnace, and at the same time provides additional energy supply, which helps to improve the overall production efficiency.

[0022] Preferably, the high - temperature resistant closed container 2 of the present invention is modularly designed, so that it can be conveniently installed in different graphitization furnace production environments and is also easy to maintain and replace. Please continue to refer to Figure 2 , the closed container 2 of the present invention includes a shell 21 and an end cover 22 that are hermetically connected. A phase change material is provided as the working medium 23 inside the shell 21. The area of the shell 21 in contact with the hot fluid is the evaporation section 24, and the area of the shell 21 in contact with the cold fluid is the condensation section 25. An adiabatic section 26 is provided between the evaporation section 24 and the condensation section 25.

[0023] By adopting the above technical solutions, the application range of the recovery device of the present invention is expanded, and it can still maintain an efficient waste heat recovery function under different production conditions.

[0024] Preferably, the phase change material used in the present invention has a melting point range between 600 °C and 1000 °C, which can adapt to the high-temperature working environment of the graphitization furnace, and turns into a liquid state after absorbing a large amount of heat to store thermal energy. During the cooling stage, the solidification process of the phase change material releases the stored heat, and the reuse of thermal energy is achieved through the heat exchange device.

[0025] By adopting the above technical solution, the high-temperature waste heat generated in the graphitization furnace can be effectively absorbed and stored, realizing the efficient utilization of energy.

[0026] Preferably, the cooling system 3 of the present invention is precisely adjusted by an automatic control device to ensure that the temperature change during the cooling process conforms to the physical properties of the phase change material, making the heat release process stable and efficient. The cooling system can select air cooling, liquid cooling or mixed cooling methods according to different production requirements to achieve the best cooling effect.

[0027] By adopting the above technical solution, the stability and controllability of the heat energy release process can be ensured, and the waste heat recovery efficiency of the device can be further improved.

[0028] Preferably, the heat exchange device 1 of the present invention is designed as a modular structure, which is convenient for adjustment and expansion according to production requirements. High-efficiency heat-conducting materials are used inside the heat exchange device 1 to ensure that the recovered heat can be quickly conducted to the processes that require thermal energy, such as preheating the feed of the graphitization furnace, providing heat sources for other equipment or used for power generation.

[0029] By adopting the above technical solution, the thermal energy utilization efficiency of the whole system can be improved, and the recycling of energy can be realized.

[0030] Preferably, the thermal energy storage unit can be used in conjunction with the heat exchange device. When the heat is not needed temporarily, the recovered heat is stored and released when needed, ensuring the maximum utilization of energy.

[0031] A specific embodiment is given below.

[0032] Thermal energy absorption: During the cooling stage of the graphitization furnace, a closed container made of a high-temperature resistant alloy is placed in the high-temperature area of the furnace. The container is filled with an inorganic salt phase change material with a melting point of 800 °C. When the furnace temperature exceeds 800 °C, the phase change material changes from a solid state to a liquid state, absorbing and storing the high-temperature heat.

[0033] Thermal energy storage: The liquid phase change material stores heat in the container, and the outside of the container is coated with high-efficiency heat insulation materials to reduce heat loss and ensure long-term storage of thermal energy. This step continues until the furnace cools below 500 °C.

[0034] Heat energy release: When the kiln cools down to 500 °C, start the liquid cooling system to cool down the container. The cooling system precisely adjusts the cooling rate through an automatic control device, enabling the phase change material to slowly solidify under low-temperature conditions and release the previously stored heat.

[0035] Heat energy reuse: Through an efficient heat exchange device, transfer the released heat to the preheating system of the graphitization kiln for preheating the kiln feed. The design of the heat exchange device ensures efficient heat transfer and provides a stable heat source support for other industrial equipment.

[0036] Effect analysis: During the implementation process, the device significantly improved the cooling efficiency of the kiln, reducing the cooling time by 30%. The energy utilization efficiency increased by 20%, and at the same time, the process of heat energy reuse provided a stable heat source support for other equipment. The self-circulating waste heat recovery system not only improved the overall efficiency of graphite electrode production but also effectively reduced energy waste.

[0037] Compared with the traditional graphitization furnace cooling method, the present invention has the following advantages: (1) By efficiently recovering and reusing the high-temperature waste heat of the graphitization kiln, the device effectively reduces energy waste and significantly improves the overall energy utilization efficiency; (2) The device accelerates the cooling process of the graphitization kiln, shortening the cooling time by 30% and reducing the demand for external heat sources at the same time, thereby reducing the energy cost during the production process; (3) By effectively transferring the recovered waste heat to other industrial processes, the device reduces the resource waste caused by heat dissipation and provides a stable heat source support for other processes.

[0038] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the claims.

Claims

1. A self-circulating waste heat recovery device for graphite electrode production, characterized in that, It includes a closed container, a cooling system and a heat exchange device, and the closed container is filled with a phase change material.

2. The self-circulating waste heat recovery device for graphite electrode production according to claim 1, characterized in that, The phase change material is a high-temperature metal alloy or inorganic salt material with a melting point between 600°C and 1000°C.

3. The self-circulating waste heat recovery device for graphite electrode production according to claim 2, wherein, The high-temperature metal alloy is sodium-potassium alloy, magnesium-aluminum alloy or copper-aluminum alloy.

4. The self-circulating waste heat recovery device for graphite electrode production according to claim 2, characterized in that, The inorganic salts are lithium carbonate, calcium chloride or potassium nitrate.

5. The self-circulating waste heat recovery device for graphite electrode production according to claim 1, characterized in that, The closed container is made of a high-temperature resistant alloy, and the material of the closed container is tungsten-based alloy, tantalum-based alloy, rhenium-based alloy or molybdenum-based alloy.

6. The self-circulating waste heat recovery device for graphite electrode production according to claim 5, wherein, The closed container includes a shell and an end cap that are hermetically connected. A phase change material is provided as a working medium inside the shell; the area of the shell in contact with the hot fluid is the evaporation section, and the area of the shell in contact with the cold fluid is the condensation section; an adiabatic section is provided between the evaporation section and the condensation section.

7. The self-circulating waste heat recovery device for graphite electrode production according to claim 5, wherein The outside of the closed container is covered with a heat insulation layer.

8. The self-circulating waste heat recovery device for graphite electrode production according to claim 1, characterized in that, The number of the closed containers is multiple, and they are arranged in an equally spaced array and are attached to the graphite insulation layer of the graphitization furnace.

9. The self-circulating waste heat recovery device for graphite electrode production according to claim 1, characterized in that, The heat exchange device further includes a thermal energy storage unit for storing and retaining the recovered heat.

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