A series connection graphitization furnace waste heat utilization system

Abstract

A series connection graphitization furnace waste heat utilization system relates to the technical field of graphitization furnace waste heat utilization equipment for continuous production of negative electrode materials, a material box for loading materials is arranged in the graphitization furnace, the material box is internally provided with a hollow first channel, the graphite electrode of the furnace head is internally provided with a second channel, the graphite block below the graphite electrode is internally provided with a third channel, the fourth channel is arranged in the castable at the bottom of the furnace head, the fifth channel for connecting the first channel and the external cooling and heat transfer medium circulating pipeline is arranged at the tail part of the furnace, the first, second, third, fourth and fifth channels are connected with each other to form the internal cooling and heat transfer medium circulating channel, and the external cooling and heat transfer medium circulating pipeline for connecting the internal cooling and heat transfer medium circulating channels of adjacent graphitization furnaces is further included. The heat of the furnace cooling chamber is used for preheating of the adjacent furnace chamber, so that the cooling period of the series connection graphitization furnace can be obviously shortened, and the heat stored in the series connection graphitization furnace can be utilized.

Description

Technical Field

[0001] This invention relates to the technical field of waste heat utilization equipment for graphitization furnaces in continuous production of negative electrode materials, and particularly to a waste heat utilization system for graphitization furnaces connected in series. Background Technology

[0002] The core characteristics of traditional series graphitization furnaces are: rapid heating upon power-on and a long cooling cycle after discharging. Typically, the heating cycle for a series graphitization furnace is approximately 18-24 hours, and the cooling time is approximately 20-30 days. The length of the cooling time determines the furnace's operating cycle and production efficiency. Furthermore, during the cooling process, the furnace body and the material itself store a large amount of heat energy. External forced or natural cooling methods result in significant heat loss and low heat reuse rates.

[0003] Therefore, how to effectively shorten the cooling cycle and recover and utilize this waste heat is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a waste heat utilization system for a series graphitization furnace, which uses the heat from the furnace cooling chamber to preheat adjacent furnace chambers, which can significantly shorten the cooling cycle of the series graphitization furnace and utilize the heat stored inside the series graphitization furnace.

[0005] To achieve the above objectives, the main technical solutions adopted by the present invention include: A waste heat utilization system for a series-connected graphitization furnace includes a material hopper inside the furnace. The hopper has a hollow first channel, with the material filling area between the first channel and the outer wall of the hopper. A second channel is located inside the graphite electrode at the furnace head, a third channel is located inside the graphite block below the graphite electrode, a fourth channel is located in the refractory material at the bottom of the furnace head, and a fifth channel at the furnace tail connects the first channel to an external cooling and heat transfer medium circulation pipeline. The first, second, third, fourth, and fifth channels are interconnected, forming an internal cooling and heat transfer medium circulation channel. The system also includes an external cooling and heat transfer medium circulation pipeline for connecting the internal cooling and heat transfer medium circulation channels of adjacent graphitization furnaces, thus forming a complete cooling and heat transfer medium circulation flow channel connecting adjacent series-connected graphitization furnaces. The external cooling and heat transfer medium circulation pipeline includes a high-temperature circulating fan and a cooling and heat transfer medium replenishment port.

[0006] Furthermore, the cooling and heat transfer medium can be nitrogen gas, which cools the graphitization furnace that needs to be cooled and carries the waste heat to an adjacent graphitization furnace for waste heat utilization.

[0007] Furthermore, the material box has a cylindrical hollow structure with a cylindrical first channel at its center. A connecting rib is provided between the first channel and the outer wall. The material box is made of graphite. The material boxes are filled sequentially along the length of the graphitization furnace core, and annular graphite pads are used to fill the gaps between adjacent material boxes.

[0008] Furthermore, the outside of the material bin is equipped with insulation material to maintain the reaction temperature of the material.

[0009] Furthermore, channels are opened on one end and the lower end face of the graphite electrode facing the furnace core to form an inverted L-shaped second channel, which is used to connect the first channel and the third channel.

[0010] Furthermore, two adjacent graphitization furnaces can be connected by a straight external cooling and heat transfer medium circulation pipeline to form a cooling and heat transfer medium circulation channel.

[0011] Furthermore, a high-temperature circulating fan is installed on the external cooling and heat transfer medium circulation pipeline near the furnace head of the graphitization furnace, and a cooling and heat transfer medium replenishment port is installed on the external cooling and heat transfer medium circulation pipeline near the furnace tail of the graphitization furnace.

[0012] Furthermore, when a group of graphitization furnaces in the workshop includes more than two graphitization furnaces connected in series, the multiple graphitization furnaces are connected in series sequentially through external cooling and heat transfer medium circulation pipelines to form a multi-furnace series waste heat utilization system.

[0013] The beneficial effects of this invention are: 1. This invention connects the nitrogen circulation channel inside the feed box at the furnace core of the graphitization furnace and the external nitrogen circulation pipeline, thereby transferring the heat stored in the connected graphitization furnace in the cooled state after exiting the furnace to the adjacent heated connected graphitization furnace for preheating. This fully utilizes the heat during the cooling cycle of the connected graphitization furnace, improving the waste heat utilization efficiency. At the same time, it reduces the power consumption of the heating furnace chamber, saving energy and reducing carbon emissions.

[0014] 2. The waste heat utilization structure of the present invention can significantly increase the cooling effect of the series graphitization furnace. Under the cooling state, the external cooling method of the series graphitization furnace remains unchanged. The internal area of ​​the furnace core changes from natural cooling to forced cooling through the nitrogen circulation channel, which significantly reduces the cooling cycle of the series graphitization furnace and improves the operating efficiency of the series graphitization furnace.

[0015] 3. The waste heat utilization structure of the present invention changes the structure of the furnace core material box and processes the carbon blocks and graphite blocks, and cooperates with the external nitrogen circulation pipeline to realize the transfer of heat by nitrogen in a closed space. The overall structure of the circulation pipeline is simple, low in cost, easy to install and maintain, and can be used with intelligent equipment to monitor the temperature changes in the pipeline in real time and realize automatic control. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the longitudinal section structure of the present invention; Figure 2 This is a schematic diagram of the pipeline connection of the present invention; Figure 3 This is a schematic cross-sectional view of the material box of the present invention.

[0017] In the diagram: 1. Graphite electrode; 2. Graphite block; 3. Castable refractory; 4. Material box; 5. External cooling and heat transfer medium circulation pipeline; 6. Cooling and heat transfer medium circulation channel; 7. High-temperature circulating fan; 8. Cooling and heat transfer medium replenishment port; 9. Graphitization furnace a; 10. Graphitization furnace b; 11. Insulation material. Detailed Implementation

[0018] To better explain and facilitate understanding of the present invention, a detailed description of the invention is provided below with reference to the accompanying drawings and specific embodiments. In this document, directional terms such as "upper" and "lower" are used interchangeably with other directional terms. Figure 1 The orientation is used as a reference.

[0019] like Figure 1-3 As shown, this invention provides a waste heat utilization system for a series-connected graphitization furnace. A material hopper 4 is installed inside the graphitization furnace for filling materials. The material hopper 4 has a hollow first channel inside, and the area between the first channel and the outer wall of the material hopper 4 is the material filling area. Specifically, the material hopper 4 is a cylindrical hollow structure with a cylindrical first channel at its center. A connecting rib is provided between the first channel and the outer wall. The material hopper 4 is made of graphite. For ease of processing, transportation, and installation, the material hopper 4 can be configured as several shorter hoppers. During installation, several hoppers 4 are filled sequentially along the length of the graphitization furnace core, with annular graphite pads used to fill the gaps between adjacent hoppers 4. The first channels inside the several hoppers 4 are interconnected, forming a cooling and heat transfer medium circulation channel that runs through the material area of ​​the series-connected graphitization furnace. Insulating material 11 is provided on the outside of the material hopper 4 to maintain the material reaction temperature. Specifically, the cooling and heat transfer medium is nitrogen. This structure of the material hopper 4 satisfies both the material filling requirements and forms an internal cooling and heat transfer medium circulation channel 6.

[0020] This invention constructs a nitrogen circulation channel through the material area of ​​a series graphitization furnace by filling a cylindrical hollow material box inside the furnace core. This channel is connected to the internal masonry and processing channels at both ends of the furnace head. An external nitrogen circulation pipeline connects two adjacent series graphitization furnaces, thus forming a complete cooling and heat transfer medium circulation pipeline that combines preheating and cooling effects. This pipeline can transfer heat from the cooled series graphitization furnace to the adjacent heated series graphitization furnace, and can also force-cool the material-filled area inside the cooled series graphitization furnace.

[0021] The graphite electrode 1 and graphite block 2 at the furnace head are machined internally, and the refractory castable 3 at the lower end of the furnace head is pre-cast to form a cooling and heat transfer medium flow channel inside the graphitization furnace. Specifically, the graphite electrode 1 at the furnace head has a second channel inside, specifically, a channel is opened at one end of the graphite electrode 1 facing the furnace core and the lower end face, forming an inverted L-shaped second channel, used to connect the first channel and the third channel. The graphite block 2 below the graphite electrode 1 has a third channel inside, the castable 3 at the bottom of the furnace head has a fourth channel, and the tail of the furnace has a fifth channel connecting the first channel and the external cooling and heat transfer medium circulation pipeline 5. The first, second, third, fourth, and fifth channels are interconnected to form an internal cooling and heat transfer medium circulation channel 6. It also includes an external cooling and heat transfer medium circulation pipeline 5 for connecting the internal cooling and heat transfer medium circulation channel 6 of adjacent graphitization furnaces. The internal cooling and heat transfer medium circulation channel 6 and the external cooling and heat transfer medium circulation pipeline 5 constitute a complete nitrogen circulation flow channel connecting two graphitization furnaces connected in series. The external cooling and heat transfer medium circulation pipeline 5 is equipped with a cooling and heat transfer medium replenishment port 8 to replenish nitrogen in the pipeline in a timely manner and prevent internal oxidation; at the same time, a high-temperature circulating fan 7 is installed on the external cooling and heat transfer medium circulation pipeline 5 to provide power for the nitrogen to circulate in the pipeline.

[0022] Two adjacent graphitization furnaces are connected by a straight external cooling and heat transfer medium circulation pipeline 5 and a cooling and heat transfer medium circulation channel 6. Specifically, as shown... Figure 2 As shown, the cooling and heat transfer medium circulation channels 6 inside the two adjacent graphitization furnaces a9 and b10 are connected to the external cooling and heat transfer medium circulation pipes 5. A high-temperature circulating fan 7 is installed on the external cooling and heat transfer medium circulation pipe 5 near the furnace head, and a cooling and heat transfer medium replenishment port 8 is installed on the external cooling and heat transfer medium circulation pipe 5 near the furnace tail, which can continuously provide cooling and heat transfer medium and circulation power to the inside of the pipes.

[0023] When a group of graphitization furnaces in the workshop includes more than two graphitization furnaces connected in series, the multiple graphitization furnaces are connected in series sequentially through external cooling and heat transfer medium circulation pipelines 5 to form a multi-furnace series waste heat utilization system. When a single group of graphitization furnaces is heated and cooled sequentially, heat transfer and forced internal cooling are provided through internal and external cooling and heat transfer medium circulation channels.

[0024] This invention forms a complete cooling and heat transfer medium circulation channel by connecting the internal cooling and heat transfer medium circulation channels of the graphitization furnace in series and the external cooling and heat transfer medium circulation pipelines connecting adjacent graphitization furnaces in a single group. When the graphitization furnace a9 in series is powered on for heating, the high-temperature circulating fan 7 is in the off state, and there is no nitrogen circulation inside.

[0025] When the series-connected graphitization furnace a9 completes its heating and enters its natural cooling cycle, the adjacent series-connected graphitization furnace b10 will be energized and heated. At this time, the high-temperature circulating fan 7 is activated to forcibly cool the series-connected graphitization furnace a9, which is in a cooled state after exiting the furnace. The heat stored inside a9 is carried into the heating series-connected graphitization furnace b10 through a cooling and heat transfer medium, specifically nitrogen gas, for preheating the heating series-connected graphitization furnace b10. When the internal temperature of the heating series-connected graphitization furnace b10 reaches approximately 700-800 degrees Celsius, the high-temperature circulating fan 7 will be shut down, stopping the heat exchange between the adjacent series-connected graphitization furnaces.

[0026] A typical workshop unit consists of multiple graphitization furnaces connected in series via cooling and heat transfer medium circulation pipelines. These furnaces undergo sequential heating and cooling cycles. During the cooling phase, heat from the furnaces is channeled through a high-temperature circulating fan (7) to circulate nitrogen gas within the circulation pipelines, preheating the heating furnaces. Once the heating furnaces reach 700-800 degrees Celsius, the high-temperature circulating fan (7) stops operating, completing the preheating process. Simultaneously, forced cooling is achieved within the cooling furnaces, shortening the furnace exit cycle.

[0027] When the waste heat utilization structure is in operation, the cooling and heat transfer medium, specifically nitrogen, can be replenished to the cooling and heat transfer medium circulation pipeline in a timely manner through the cooling and heat transfer medium replenishment port 8, ensuring uninterrupted operation and preventing oxidation of the heated materials inside the graphitization furnace and the furnace head electrodes. The waste heat device of this invention has a simple pipeline structure, facilitating maintenance and replacement.

[0028] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any modifications, alterations, substitutions, and variations made by those skilled in the art to the above embodiments are within the scope of the present invention.

Claims

1. A waste heat utilization system for a series-connected graphitization furnace, characterized in that: A material box (4) for filling materials is set inside the graphitization furnace. The material box (4) has a hollow first channel inside. The material filling area is between the first channel and the outer wall of the material box (4). The graphite electrode (1) at the furnace head has a second channel inside. The graphite block (2) below the graphite electrode (1) has a third channel inside. The casting material (3) at the bottom of the furnace head has a fourth channel. The tail of the furnace has a fifth channel that connects the first channel with the external cooling and heat transfer medium circulation pipeline (5). The first, second, third, fourth and fifth channels are interconnected to form an internal cooling and heat transfer medium circulation channel (6). It also includes an external cooling and heat transfer medium circulation pipeline (5) for connecting the internal cooling and heat transfer medium circulation channel (6) of the adjacent graphitization furnace. The external cooling and heat transfer medium circulation pipeline (5) is equipped with a high-temperature circulating fan (7) and a cooling and heat transfer medium replenishment port (8).

2. The waste heat utilization system for a series-connected graphitization furnace according to claim 1, characterized in that: Nitrogen is used as the cooling and heat transfer medium.

3. The waste heat utilization system for a series-connected graphitization furnace according to claim 1, characterized in that: The material box (4) is a cylindrical hollow structure with a cylindrical first channel at its center. A connecting rib is provided between the first channel and the outer wall. The material box (4) is made of graphite. The material boxes (4) are filled sequentially along the length of the graphitization furnace core. An annular graphite pad is used to fill the gaps between adjacent material boxes (4).

4. A waste heat recovery system for a series-connected graphitization furnace according to claim 1 or 3, characterized in that: The material box (4) is equipped with insulation material (11) on the outside.

5. The waste heat utilization system for a series-connected graphitization furnace according to claim 1, characterized in that: The graphite electrode (1) has a channel facing one end of the furnace core and the lower end face to form an inverted L-shaped second channel.

6. The waste heat utilization system for a series-connected graphitization furnace according to claim 1, characterized in that: The two adjacent graphitization furnaces are connected by a straight external cooling and heat transfer medium circulation pipeline (5) to the cooling and heat transfer medium circulation channel (6).

7. A waste heat utilization system for a series-connected graphitization furnace according to claim 1 or 6, characterized in that: A high-temperature circulating fan (7) is provided on the external cooling and heat transfer medium circulation pipeline (5) near the furnace head of the graphitization furnace, and a cooling and heat transfer medium replenishment port (8) is provided on the external cooling and heat transfer medium circulation pipeline (5) near the furnace tail of the graphitization furnace.

8. The waste heat utilization system for a series-connected graphitization furnace according to claim 1, characterized in that: When a group of graphitization furnaces in the workshop contains more than two graphitization furnaces connected in series, the multiple graphitization furnaces are connected in series in sequence through external cooling and heat transfer medium circulation pipelines (5) to form a waste heat utilization system with multiple furnaces connected in series.

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