A low-carbon furnace grate exhaust duct for carbon fiber production

Abstract

The utility model belongs to carbon fiber production technical field, concretely relates to a kind of carbon fiber production low-carbon grate waste pipeline, including low-carbon furnace shell, the low-carbon furnace shell symmetry two side walls are respectively provided with a group of exhaust components, one group of the exhaust components is connected left waste gas collection pipe by four-way pipe, another group of the exhaust components is connected right waste gas collection pipe by four-way pipe, total exhaust pipe is commonly provided on the left waste gas collection pipe and right waste gas collection pipe, the left waste gas collection pipe, right waste gas collection pipe and total exhaust pipe are all segmented structure composition, and each section pipeline is connected by flange, the left waste gas collection pipe of the utility model, right waste gas collection pipe and total exhaust pipe adopt segmented detachable design, and each section pipeline is connected by flange, when pipeline is seriously blocked or pipeline is damaged, quickly dismounting pipeline is dredged or replaced, maintenance difficulty is greatly reduced, equipment downtime is reduced, and equipment operation and maintenance efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of carbon fiber production technology, specifically relating to a low-carbon furnace grate waste pipe for carbon fiber production. Background Technology

[0002] Carbon fiber is a high-strength, high-modulus fiber material with a carbon content of over 90%. It combines the high hardness, high temperature resistance, and chemical resistance of graphite with the softness and processability of textile fibers, and is widely used in aerospace, civil engineering, military, and competitive sports. The production of acrylonitrile-based carbon fiber involves pre-oxidation, carbonization (divided into low-temperature and high-temperature carbonization), and post-treatment processes. Low-temperature carbonization is a transitional stage between pre-oxidation and high-temperature carbonization. During this stage, the pre-oxidized fiber undergoes a cracking reaction, removing small molecule gases such as CO2, H2O, HCN, and NH3, as well as a large amount of tar. Simultaneously, the cyclic structure recombines to form aromatic ring planes, and the fiber aggregate transforms from an amorphous to a crystalline state. The high-temperature carbonization stage further denitrifies the fiber and rearranges the aromatic ring structure into a disordered layered graphite structure, giving the carbon fiber excellent mechanical properties.

[0003] As a key piece of equipment in the carbonization process, the design of the exhaust gas pipeline in a low-temperature carbonization furnace directly affects production stability and product quality. Existing technologies related to exhaust gas discharge from low-temperature carbonization furnaces have several shortcomings, such as: 1. Top exhaust port device with tar collection function (CN220034757U): This patent uses an arc-shaped baffle to collect tar from the top exhaust port and changes the suction method to prevent tar from dripping onto the fiber bundle. However, it only focuses on tar treatment at the top exhaust port and does not design an anti-condensation structure for the main body of the exhaust pipe (such as long straight sections and non-top bends). The tar still liquefies and deposits inside the pipe body due to temperature drop. Moreover, the pipe does not have a convenient disassembly and cleaning design, making it difficult to remove the deposited tar. Long-term use can easily cause pipe blockage and affect the exhaust gas discharge efficiency.

[0004] 2. High-efficiency carbon fiber low-temperature carbonization furnace waste discharge pipeline system (CN207002883U): This patent specifies parameters such as pipeline length, number of bends, cleaning chamber, and insulation treatment. While it optimizes waste discharge efficiency to some extent, it does not design a thermal deformation compensation structure for the connection between the pipeline and the low-carbon furnace waste discharge port. The temperature inside the low-carbon furnace cavity can reach 800~1000℃, and the connection between the pipeline and the furnace body is prone to deformation due to thermal expansion and contraction, leading to pipeline seal failure or cracking. At the same time, it relies solely on the cleaning chamber to clean the pipeline, and the convenience and thoroughness of cleaning areas prone to tar accumulation, such as bends, are insufficient.

[0005] 3. Waste discharge system and cleaning method of polyacrylonitrile-based carbon fiber production equipment (CN115945471A): This patent achieves start-up cleaning by introducing steam into the cleaning pipeline and coating the inner surface of the pipeline with an oleophobic layer to reduce tar adhesion. However, the cleaning process requires precise control of parameters such as steam temperature (100~180℃) and pressure (0.5~1.5MPa), which is complex to operate and relies on additional cleaning equipment. In addition, the pipeline does not adopt a segmented and detachable design. When the pipeline is severely blocked or damaged, it cannot be quickly disassembled and replaced, which can easily lead to production downtime and increase operation and maintenance costs and time. Utility Model Content

[0006] This invention addresses the problem of time-consuming maintenance and cleaning of low-carbon furnace pipelines, which affects production efficiency, by providing a waste discharge pipeline for low-carbon furnaces in carbon fiber production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A waste discharge pipe for a low-carbon furnace in carbon fiber production includes a low-carbon furnace shell. A set of waste discharge components is respectively arranged on the symmetrical side walls of the low-carbon furnace shell. The waste discharge components are divided into a front waste discharge port, a middle waste discharge port, and a rear waste discharge port. One set of the waste discharge components is connected to a left waste gas collection pipe via a four-way pipe, and the other set of waste discharge components is connected to a right waste gas collection pipe via a four-way pipe. A main waste discharge pipe is provided on both the left and right waste gas collection pipes. The left and right waste gas collection pipes are respectively connected to the main waste discharge pipe via four-way pipes. The left, right, and main waste discharge pipes are all composed of a segmented structure, and each segment is connected by a flange. A furnace nozzle waste discharge port is provided at the front end of the low-carbon furnace shell, and the furnace nozzle waste discharge port is connected to the main waste discharge pipe via a four-way pipe. Two channels of the four-way pipe are equipped with blind flanges.

[0008] Furthermore, electric heating wires are wound around the left exhaust gas collection pipe, the right exhaust gas collection pipe, and the main exhaust pipe, and the electric heating wires are wirelessly connected to an external control console.

[0009] Furthermore, expansion joints are installed at the connections between the front exhaust port, the middle exhaust port, and the rear exhaust port and the left exhaust gas collection pipe and the right exhaust gas collection pipe.

[0010] Furthermore, a temperature sensor is installed in one of the left exhaust gas collection pipe, the right exhaust gas collection pipe, or the main exhaust pipe, and the temperature sensor is wirelessly connected to an external control console.

[0011] Furthermore, an insulation layer is provided on the outside of the left exhaust gas collection pipe, the right exhaust gas collection pipe, and the main exhaust pipe. The insulation layer is made of high-temperature resistant insulation material.

[0012] Furthermore, the connection between the blind flange and the four-way pipe is configured as a quick-opening structure.

[0013] Compared with the prior art, the present invention has the following advantages: 1. The left exhaust gas collection pipe, right exhaust gas collection pipe, and main exhaust pipe of this utility model adopt a segmented and detachable design, and each section of the pipe is connected by flanges. In case of severe blockage or damage to the pipe, the pipe can be quickly disassembled for unblocking or replacement, which greatly reduces maintenance difficulty, reduces equipment downtime, improves equipment operation and maintenance efficiency, reduces tar deposition in the pipe and avoids pipe blockage. It eliminates the possibility of liquefied tar gas dripping into the filament bundle in the furnace from the source, which can comprehensively prevent tar adhesion from damaging the filament bundle performance, ensure that the filament bundle can stably form a carbon network structure with good mechanical properties, effectively avoid filament bundle breakage, improve the strength, modulus and other key indicators of carbon fiber products, and reduce the production scrap rate.

[0014] 2. This utility model uses an electric heating wire wound around the left exhaust gas collection pipe, the right exhaust gas collection pipe, and the main exhaust pipe. Combined with the external insulation layer, it can maintain a stable internal temperature of the pipe for a long time. A temperature sensor is installed on one of the pipes to monitor the internal temperature and transmit the temperature data to an external control console. The operator can control the temperature of the electric heating wire through the external control console to achieve a continuous and stable temperature.

[0015] 3. In this invention, the left and right exhaust gas collection pipes are respectively connected to the main exhaust pipe via four-way pipes. Two of these channels are used for exhaust, while the other two channels are fitted with blind flanges. After the blind flanges are removed, it is easy to clean the deposited tar in the pipes. This allows for more direct and thorough cleaning of tar that is prone to deposit at bends, further reducing the risk of pipe blockage and minimizing the impact of untimely cleaning on exhaust efficiency. By reducing tar deposition in the pipes and ensuring smooth exhaust, this invention avoids local environmental anomalies caused by exhaust gas stagnation in the furnace. It ensures that the pre-oxidized fibers can undergo normal cracking reactions, intermolecular recombination, and aggregation structure transformation during the low-temperature carbonization process, ensuring a stable transition from the low-temperature carbonization stage to the high-temperature carbonization stage. This provides a stable process environment for the final formation of carbon fiber materials with high carbon content and excellent mechanical properties.

[0016] 4. The low-carbon furnace shell of this utility model is designed with two sets of waste discharge components and a furnace nozzle waste discharge port, which are combined with the left waste gas collection pipe, the right waste gas collection pipe and the main waste discharge pipe. In a graded collection manner, the waste gas from different areas of the low-carbon furnace can be collected quickly, avoiding the waste gas from staying in the furnace, reducing the contact time between the waste gas and the inner wall of the pipe, further reducing the probability of tar deposition, and improving the efficiency of waste gas transportation to the incinerator, ensuring the effect of subsequent harmless treatment of waste gas.

[0017] 5. This utility model uses an expansion joint to connect the waste discharge assembly, the left waste gas collection pipe and the right waste gas collection pipe. It can effectively absorb the thermal expansion and contraction deformation of the pipeline caused by the high temperature of the furnace body, avoid the pipeline from cracking or sealing failure due to thermal stress, protect the integrity of the pipeline structure, extend the service life of the pipeline, and prevent high temperature waste gas leakage, thereby reducing equipment safety hazards. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the waste outlet structure of the low-carbon furnace of this utility model; Figure 2 This is a top view of the present invention; Figure 3 This is the front view of the present invention; Figure 4 This is a side view of the present invention; In the figure, the components are: 1. Low-carbon furnace shell; 2. Waste discharge assembly; 3. Front waste discharge port; 4. Middle waste discharge port; 5. Rear waste discharge port; 6. Left waste gas collection pipe; 7. Right waste gas collection pipe; 8. Main waste discharge pipe; 9. Four-way pipe; 10. Blind flange; 11. Furnace nozzle waste discharge port; 12. Electric heating wire; 13. Expansion joint; 14. Temperature sensor; 15. Insulation layer. Detailed Implementation

[0019] To further illustrate the technical solution of this utility model, the following embodiments will be used to further explain this utility model. Example

[0020] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a waste discharge pipe for a low-carbon furnace in carbon fiber production includes a low-carbon furnace shell 1. A set of waste discharge components 2 are respectively arranged on the symmetrical side walls of the low-carbon furnace shell 1. The waste discharge components 2 are divided into a front waste discharge port 3, a middle waste discharge port 4, and a rear waste discharge port 5. One set of waste discharge components 2 is connected to a left waste gas collection pipe 6 via a four-way pipe 9, and the other set of waste discharge components 2 is connected to a right waste gas collection pipe 7 via a four-way pipe 9. A main waste discharge pipe 8 is provided on both the left and right waste gas collection pipes 6 and 7. The left and right waste gas collection pipes 6 and 7 are respectively connected to the main waste discharge pipe 8 via four-way pipes 9. The left, right, and main waste discharge pipes 6 and 7 are all composed of a segmented structure, and each segment is connected by a flange. Electric heating wires are wound around the left, right, and main waste discharge pipes 6 and 7. 12. The electric heating wire 12 is wirelessly connected to an external control console. The front end of the low-carbon furnace shell 1 is provided with a furnace nozzle exhaust port 11. The furnace nozzle exhaust port 11 is connected to the main exhaust pipe 8 through a four-way pipe 9. Two channels of the four-way pipe 9 are equipped with blind flanges 10. Expansion joints 13 are installed at the connection points between the front exhaust port 3, the middle exhaust port 4, and the rear exhaust port 5 and the left exhaust gas collection pipe 6 and the right exhaust gas collection pipe 7. A temperature sensor 14 is provided in one of the left exhaust gas collection pipe 6, the right exhaust gas collection pipe 7, or the main exhaust pipe 8. The temperature sensor 14 is wirelessly connected to an external control console. An insulation layer 15 is provided on the outside of the left exhaust gas collection pipe 6, the right exhaust gas collection pipe 7, and the main exhaust pipe 8. The insulation layer 15 is made of high-temperature resistant insulation material. The connection between the blind flange 10 and the four-way pipe 9 is a clamp-type structure.

[0021] The foregoing has shown and described the main features and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model.

[0022] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-carbon waste grate pipe for carbon fiber production, characterized in that: The furnace includes a low-carbon furnace shell (1). A set of waste discharge components (2) is provided on each of the symmetrical side walls of the low-carbon furnace shell (1). The waste discharge components (2) are divided into a front waste discharge port (3), a middle waste discharge port (4), and a rear waste discharge port (5). One set of the waste discharge components (2) is connected to the left waste gas collection pipe (6) through a four-way pipe (9), and the other set of the waste discharge components (2) is connected to the right waste gas collection pipe (7) through a four-way pipe (9). A main waste discharge pipe (8) is provided on both the left waste gas collection pipe (6) and the right waste gas collection pipe (7). The left exhaust gas collection pipe (6) and the right exhaust gas collection pipe (7) are connected to the main exhaust pipe (8) through a four-way pipe (9). The left exhaust gas collection pipe (6), the right exhaust gas collection pipe (7) and the main exhaust pipe (8) are all composed of a segmented structure, and each segment of the pipe is connected by a flange. The front end of the low-carbon furnace shell (1) is provided with a furnace nozzle exhaust port (11). The furnace nozzle exhaust port (11) is connected to the main exhaust pipe (8) through a four-way pipe (9). Two of the channels of the four-way pipe (9) are equipped with blind plates (10).

2. The low-carbon waste grate pipe for carbon fiber production according to claim 1, characterized in that: Electric heating wires (12) are wound around the left exhaust gas collection pipe (6), the right exhaust gas collection pipe (7) and the main exhaust pipe (8), and the electric heating wires (12) are wirelessly connected to an external control console.

3. The low-carbon waste grate pipe for carbon fiber production according to claim 1, characterized in that: Expansion joints (13) are installed at the connection points between the front exhaust port (3), the middle exhaust port (4), and the rear exhaust port (5) and the left exhaust gas collection pipe (6) and the right exhaust gas collection pipe (7).

4. The low-carbon waste grate pipe for carbon fiber production according to claim 1, characterized in that: A temperature sensor (14) is provided in one of the left exhaust gas collection pipe (6), the right exhaust gas collection pipe (7) or the main exhaust pipe (8), and the temperature sensor (14) is wirelessly connected to an external control console.

5. The low-carbon waste grate pipe for carbon fiber production according to claim 1, characterized in that: An insulation layer (15) is provided on the outside of the left exhaust gas collection pipe (6), the right exhaust gas collection pipe (7) and the main exhaust pipe (8), and the insulation layer (15) is made of high temperature resistant insulation material.

6. The low-carbon waste grate pipe for carbon fiber production according to claim 1, characterized in that: The connection between the blind flange (10) and the four-way pipe (9) is configured as a quick-opening structure.

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