Carbonization tail gas treatment system in carbon fiber production and carbon fiber production system

Abstract

The utility model relates to a carbonization tail gas treatment system in carbon fiber production and a carbon fiber production system.The carbonization tail gas treatment system in the carbon fiber production comprises a heat exchanger, a tail gas inlet and a gas outlet are formed in the upper portion of the heat exchanger, and a gas inlet and a material outlet are formed in the lower portion of the heat exchanger; the gas-liquid separation mechanism is provided with a feeding port and a gas outlet, the feeding port is communicated with the material outlet, and the gas-liquid separation mechanism is located below the heat exchanger; a waste gas outlet and a solvent inlet are formed in the upper part of the tar removal device, a tail gas inlet and a liquid outlet are formed in the lower part of the tar removal device, and the tail gas inlet is communicated with the gas outlet. In the utility model, the tail gas exchanges heat with gases such as nitrogen in the heat exchanger, so that the temperature of the tail gas is reduced, tar is condensed after being cooled, is removed from the tail gas, and enters the gas-liquid separation mechanism under the action of gravity for gas-liquid separation; and the separated tail gas enters a tar removal device, and the introduced solvent can dissolve and absorb tar and hydrogen cyanide which are relatively high in viscosity at low temperature, so that the tar and the hydrogen cyanide are removed from the tail gas.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical production equipment, and in particular relates to a carbonization tail gas treatment system in carbon fiber production and a carbon fiber production system. Background Art

[0002] Carbon fiber is a synthetic inorganic fiber with a carbon content of over 90% that is made from organic materials such as polyacrylonitrile and asphalt through polymerization, oxidation, and carbonization. Carbon fiber has excellent properties such as low density, high specific strength (35 times that of steel and over 4 times that of aluminum alloy), high modulus, high temperature resistance, corrosion resistance, creep resistance, electrical conductivity, thermal conductivity, and a low thermal expansion coefficient. It is primarily used as a reinforcing material and is widely used in aviation, aerospace, automotive, construction, metallurgy, textiles, electronic equipment, medical equipment, and sporting goods.

[0003] Based on the type of raw materials, carbon fibers can be divided into three categories: polyacrylonitrile-based carbon fibers, viscose-based carbon fibers, and pitch-based carbon fibers. Among them, polyacrylonitrile-based carbon fibers, which use petrochemical product acrylonitrile as the main raw material, account for more than 90% of the total carbon fiber production.

[0004] Polyacrylonitrile-based carbon fibers are made from acrylonitrile, which is copolymerized and blended into polyacrylonitrile fibers. These fibers are then oxidized to form carbonization-resistant fibers. These fibers are then carbonized in an auxiliary gas atmosphere (such as nitrogen or helium). To improve the performance of the carbon fibers, activation treatment (including surface treatment, sizing, and drying) is typically performed.

[0005] However, during the oxidation process and carbonization process, especially during the carbonization process, ammonia, hydrogen cyanide and other substances, as well as tar and other impurities will be produced. For example, during the low-temperature carbonization process, every 1000m 3 / h tail gas contains about 96kg / h of hydrogen cyanide, about 4.8kg / h of ammonia and about 76.8kg / h of tar. During the high temperature carbonization process, every 600m 3 / h exhaust gas contains about 23kg / h of hydrogen cyanide, about 0.3kg / h of ammonia and about 2.88kg / h of tar. Since the concentrations of hydrogen cyanide and ammonia far exceed the content limits of the corresponding components in the inorganic chemical industry pollutant emission standards (wherein the emission content limits of hydrogen cyanide and ammonia are 0.3mg / m 3 and 20 mg / m 3 ), so it is necessary to treat hydrogen cyanide and ammonia in the tail gas, and substances such as tar in the tail gas may block the pipeline and affect the smooth progress of production. Utility Model Content

[0006] In view of this, the utility model provides a carbonization tail gas treatment system and a carbon fiber production system in the carbonization process to solve the problems of ammonia, hydrogen cyanide and other substances, as well as tar and other impurities generated in the carbonization process. For example, in the low temperature carbonization process, every 1000m 3 / h tail gas contains about 96kg / h of hydrogen cyanide, about 4.8kg / h of ammonia and about 76.8kg / h of tar. During the high temperature carbonization process, every 600m 3 / h exhaust gas contains about 23kg / h of hydrogen cyanide, about 0.3kg / h of ammonia and about 2.88kg / h of tar. Since the concentrations of hydrogen cyanide and ammonia far exceed the content limits of the corresponding components in the national inorganic chemical industry pollutant emission standards (wherein the emission content limits of hydrogen cyanide and ammonia are 0.3mg / m 3 and 20 mg / m 3 ), so it is necessary to treat hydrogen cyanide and ammonia in the tail gas, and substances such as tar in the tail gas may clog the pipeline, affecting the smooth progress of production and other technical problems.

[0007] In order to realize the above scheme, the technical solution of the present utility model is as follows:

[0008] In a first aspect, the present invention provides an exhaust gas treatment system, comprising:

[0009] The heat exchanger has an exhaust gas inlet and outlet at the top and a gas inlet and material outlet at the bottom;

[0010] a gas-liquid separation mechanism, provided with a feed inlet and a gas outlet, wherein the feed inlet is connected to the material outlet, and the gas-liquid separation mechanism is located below the heat exchanger; and

[0011] The tar removal device is provided with a waste gas outlet and a solvent inlet at the top, and a tail gas inlet and a liquid outlet at the bottom, wherein the tail gas inlet is connected to the gas outlet.

[0012] The principle of the tail gas treatment system of the present invention is as follows: by arranging the heat exchanger to be provided with a tail gas inlet and a gas inlet, carbonized tail gas (containing hydrogen cyanide, ammonia and tar) with a relatively high temperature and auxiliary gases such as nitrogen at a low temperature can be introduced into the heat exchanger. In the heat exchanger, the carbonized tail gas (containing hydrogen cyanide, ammonia and tar) exchanges heat with auxiliary gases such as nitrogen, thereby reducing the tail gas temperature. The tar in the tail gas condenses after cooling and is removed from the tail gas; then, it enters the gas-liquid separation mechanism under the action of gravity and is separated from part of the tail gas and liquid entrained in the tar; then, the tar after gas removal is sent to the tar removal device, in which the solvent (such as benzene, toluene, acetic acid, ethanol and other substances) can dissolve and absorb tar with a relatively high viscosity at a low temperature and substances such as hydrogen cyanide, thereby removing substances such as tar and hydrogen cyanide from the tail gas.

[0013] Optionally, the tail gas inlet is connected to a main pipeline, and the main pipeline is connected to a first branch pipeline and a second branch pipeline.

[0014] Specifically, the utility model connects the exhaust gas inlet with a main pipeline, and configures the main pipeline to be connected with a first branch pipeline and a second branch pipeline. The exhaust gas with a temperature of about 600°C generated during the low-temperature carbonization process and the exhaust gas with a temperature of about 900°C generated during the high-temperature carbonization process can be mixed through the main pipeline and sent into the heat exchanger for treatment, thereby improving the treatment efficiency.

[0015] Optionally, the tail gas treatment system further includes a deamination reactor, which is connected to the exhaust gas outlet and is provided with an acid liquid inlet.

[0016] Specifically, the utility model adds a deamination reactor connected to the exhaust gas outlet, and configures the deamination reactor to have an acid inlet, so that dilute sulfuric acid and other substances that can react with ammonia in the exhaust gas can be introduced into the deamination reactor through the acid inlet, thereby removing ammonia from the exhaust gas.

[0017] Optionally, the exhaust gas treatment system further includes an induced draft fan, which is located on a communication pipe between the exhaust gas inlet and the gas outlet.

[0018] Specifically, the utility model adds an induced draft fan to the connecting pipe between the exhaust gas inlet and the gas outlet, so that the exhaust gas containing a small amount of tar can be extracted by the induced draft fan and sent into the tar removal device, providing power for the exhaust gas, and then providing sufficient exhaust gas supply to the tar removal device, thereby improving the processing efficiency.

[0019] Optionally, the gas-liquid separation mechanism is provided with a pressure gauge.

[0020] Specifically, the utility model provides the gas-liquid separation mechanism with a pressure gauge, which can adjust the pressure of the gas-liquid separation mechanism through the pressure gauge, thereby ensuring the stability of the pressure during the production process and further ensuring the stable operation of the system.

[0021] Optionally, the exhaust gas treatment system further includes a pressure control valve, which is located on the communication pipe between the gas outlet and the induced draft fan.

[0022] Specifically, the utility model adds a pressure control valve to the connecting pipe between the gas outlet and the induced draft fan, so that the pressure of the gas discharged from the gas-liquid separation mechanism can be adjusted through the pressure control valve, thereby further ensuring the stability of the pressure during the production process, and further ensuring the stable operation of the system.

[0023] Optionally, the exhaust gas treatment system also includes a gas mixer, which is located on the connecting pipe between the induced draft fan and the exhaust gas inlet. The gas mixer is provided with a circulation inlet, which is connected to the liquid outlet. A circulation pump is provided on the connecting pipe between the circulation inlet and the liquid outlet, and a cooling mechanism is provided on the connecting pipe between the circulation pump and the gas mixer.

[0024] Specifically, the utility model adds a gas mixer to the connecting pipe between the induced draft fan and the exhaust gas inlet, connects the liquid outlet to the circulation inlet of the gas mixer, and sets a circulation pump on the connecting pipe between the circulation inlet and the liquid outlet. The tar with a small amount of gas can be sent to the cooling mechanism through the circulation pump. The temperature of the tar with a small amount of gas can be reduced by the cooling mechanism. After cooling, the tar condenses, so that part of the tar is separated from the exhaust gas and liquid. After separation, the exhaust gas carrying a small amount of tar enters the gas mixer, is evenly mixed with the exhaust pumped by the induced draft fan, and then enters the tar removal device again for detarring treatment, thereby further recovering the tar.

[0025] Optionally, the tail gas treatment system further includes a tar removal mechanism and / or a hydrocyanic acid removal device, the tar removal mechanism and / or the hydrocyanic acid removal device are connected to the tar outlet and / or the circulation pump, the hydrocyanic acid removal device is provided with a hydrogen cyanide outlet, and the hydrogen cyanide outlet is connected to a hydroxyacetonitrile reactor.

[0026] Specifically, the utility model adds a tar removal mechanism and / or a hydrocyanic acid removal device, and connects the tar removal mechanism and / or the hydrocyanic acid removal device with the tar outlet and / or the circulation pump. The hydrocyanic acid removal device is connected to a hydroxyacetonitrile reactor. The tar removal mechanism can remove the solvent and hydrogen cyanide entrained in the tar, and the hydrocyanic acid removal device can remove hydrogen cyanide gas from the mixed gas. The removed hydrogen cyanide gas is fed into the hydroxyacetonitrile reactor, and hydroxyacetonitrile is produced using hydrogen cyanide gas as a raw material. While improving the purity of the tar, the resource utilization rate of hydrogen cyanide is improved, thereby improving the economic benefits.

[0027] Optionally, the hydrocyanic acid removal device is provided with a solvent outlet, and the solvent outlet is connected to the tar removal device.

[0028] Specifically, the utility model connects the solvent outlet of the hydrocyanic acid removal device to the tar removal device, so that the removed solvent can be sent to the tar removal device, thereby recycling the solvent, reducing production costs and increasing profits.

[0029] In a second aspect, the present invention further provides a carbon fiber production system, which includes the exhaust gas treatment system as described above.

[0030] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, serving to explain the principles of the present application. It is obvious that the drawings described below are merely some embodiments of the present application, and a person of ordinary skill in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0032] Figure 1 Schematic diagram of the structure of the tail gas treatment system of Example 1;

[0033] Figure 2 Schematic diagram of the structure of the tail gas treatment system of Example 2;

[0034] Figure 3 Schematic diagram of the structure of the tail gas treatment system of Example 3;

[0035] Figure 4 Schematic diagram of the structure of the tail gas treatment system of Example 4;

[0036] Figure 5 Schematic diagram of the structure of the tail gas treatment system of Example 5;

[0037] Figure 6 Schematic diagram of the structure of the tail gas treatment system of Example 6;

[0038] Figure 7 This is a schematic structural diagram of the exhaust gas treatment system of Example 7.

[0039] Reference numerals

[0040] 1-Heat exchanger;

[0041] 2- induced draft fan;

[0042] 3-tar removal unit;

[0043] 4-deamination reactor, 41-packing section, 42-tray section, 421-sieve plate, 43-liquid level gauge;

[0044] 5-gas-liquid separation mechanism, 51-pressure gauge;

[0045] 6-pressure control valve;

[0046] 7-Gas mixer;

[0047] 8-circulation pump;

[0048] 9- tar removal mechanism;

[0049] 10-hydrocyanic acid removal device;

[0050] 11- cooling mechanism;

[0051] 12-Hydroxyacetonitrile reactor. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] It should be noted that all directional indications (such as up, down, top, bottom, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0054] In this utility model, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0055] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "A and / or B" appearing in the full text is to include three parallel schemes, with "A and / or B" including scheme A, or scheme B, or a scheme in which both A and B are satisfied. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. In the process of carbon fiber production, oxidation stabilization treatment is designed. During the oxidation process and carbonization process, especially during the carbonization process, substances such as ammonia, hydrogen cyanide, and impurities such as tar will be generated. For example, during the low-temperature carbonization process, every 1000m 3 / h tail gas contains about 96kg / h of hydrogen cyanide, about 4.8kg / h of ammonia and about 76.8kg / h of tar. During the high temperature carbonization process, every 600m 3 / h exhaust gas contains about 23kg / h of hydrogen cyanide, about 0.3kg / h of ammonia and about 2.88kg / h of tar. Since the concentrations of hydrogen cyanide and ammonia far exceed the content limits of the corresponding components in the national inorganic chemical industry pollutant emission standards (wherein the emission content limits of hydrogen cyanide and ammonia are 0.3mg / m 3 and 20 mg / m 3 ), so it is necessary to treat gases such as hydrogen cyanide and ammonia in the tail gas, and substances such as tar in the tail gas may clog the pipeline, affecting the smooth progress of production. Based on the above technical problems, the first embodiment of the utility model provides a tail gas treatment system, including:

[0056] Heat exchanger 1, with an exhaust gas inlet and an exhaust outlet at the top, and a gas inlet and a material outlet at the bottom, the exhaust gas inlet is connected to the main pipeline, and the main pipeline is connected to the first branch pipeline and the second branch pipeline;

[0057] The gas-liquid separation mechanism 5 is located below the heat exchanger 1 and is provided with a feed inlet and a gas outlet. The feed inlet is connected to the material outlet and the gas-liquid separation mechanism 5 is provided with a pressure gauge 51; and

[0058] The tar removal device 3 is provided with a waste gas outlet and a solvent inlet at the top, and a tail gas inlet and a liquid outlet at the bottom, and the tail gas inlet is connected to the gas outlet.

[0059] In another embodiment of the present invention, the tail gas treatment system further comprises a deamination reactor 4 , which is connected to the exhaust gas outlet and is provided with an acid liquid inlet.

[0060] In another embodiment of the present invention, the exhaust gas treatment system further includes an induced draft fan 2, which is located on the communication pipe between the exhaust gas inlet and the gas outlet.

[0061] In another embodiment of the present invention, the exhaust gas treatment system further includes a pressure control valve 6 , which is located on the communication pipe between the gas outlet and the induced draft fan 2 .

[0062] In another embodiment of the present invention, the exhaust gas treatment system also includes a gas mixer 7, which is provided with a circulation inlet. The gas mixer 7 is located on the connecting pipe between the induced draft fan 2 and the exhaust gas inlet, and the circulation inlet is connected to the liquid outlet. A circulation pump 8 is provided on the connecting pipe between the circulation inlet and the liquid outlet, and a cooling mechanism 11 is provided on the connecting pipe between the circulation pump 8 and the gas mixer 7.

[0063] In another embodiment of the present invention, the tail gas treatment system further includes a tar removal mechanism 9 and / or a hydrocyanic acid removal device 10, the tar removal mechanism 9 and / or the hydrocyanic acid removal device 10 are connected to the tar outlet and / or the circulation pump 8, and the hydrocyanic acid removal device 10 is connected to the hydroxyacetonitrile reactor 12.

[0064] In another embodiment of the present invention, the solvent removal device 9 is provided with a solvent outlet, and the solvent outlet is connected to the tar removal device 3 .

[0065] Another embodiment of the present invention further provides a carbon fiber production system, comprising the exhaust gas treatment system as described above.

[0066] The present invention is described in detail below through specific examples. It should also be understood that the following examples are only used to specifically illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention fall within the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not limited to the specific values ​​in the following examples.

[0067] Example 1

[0068] See also Figure 1 , Figure 1 This is a schematic structural diagram of the exhaust gas treatment system shown in this embodiment. The exhaust gas treatment system can be used to treat the exhaust gas generated in the carbonization process during the carbon fiber production process. The exhaust gas treatment system includes a heat exchanger 1, a gas-liquid separation mechanism 5 and a tar removal device 3.

[0069] Please continue reading Figure 1 Heat exchanger 1 serves as a place for heat exchange with exhaust gas. An exhaust gas inlet and outlet are provided at the top of heat exchanger 1, a gas inlet and material outlet are provided at the bottom of heat exchanger 1, and a material outlet is provided at the bottom of heat exchanger 1. The exhaust gas inlet is connected to a main pipeline, which is connected to a first branch pipeline and a second branch pipeline. High-temperature carbonized exhaust gas can enter heat exchanger 1 through the exhaust gas inlet, while low-temperature gases such as nitrogen can enter heat exchanger 1 through the gas inlet at the bottom. Low-temperature gases such as nitrogen entering heat exchanger 1 gradually dissipate upward and exchange heat with the higher-temperature exhaust gas entering heat exchanger 1, thereby reducing the exhaust gas temperature. Tar in the exhaust gas condenses after cooling and is separated from the exhaust gas.

[0070] Specifically, in this embodiment, the exhaust gas inlet of the heat exchanger 1 is connected to the main pipeline 11, and the main pipeline 11 is connected to the first branch pipeline and the second branch pipeline. The exhaust gas with a temperature of about 600°C generated in the low-temperature carbonization process and the exhaust gas with a temperature of about 900°C generated in the high-temperature carbonization process can be mixed through the main pipeline and sent into the heat exchanger 1 for treatment, thereby improving the treatment efficiency.

[0071] Please continue reading Figure 1 The gas-liquid separation mechanism 5 is used to separate the removed tar (including some tail gas) into gas and liquid. The gas-liquid separation mechanism 5 is located below the heat exchanger 1 and is provided with a feed port, a gas outlet, and a pressure gauge 51. The feed port of the gas-liquid separation mechanism 5 is connected to the material outlet of the heat exchanger 1. The gas-liquid separation mechanism 5 can be a gas-liquid separator, a gas buffer tank, etc. The gas-liquid separator and the gas buffer tank are conventional technologies and will not be described in detail here.

[0072] Specifically, in this embodiment, by configuring the gas-liquid separation mechanism 5 to be provided with a pressure gauge 51 , the pressure of the gas-liquid separation mechanism 5 can be adjusted by the pressure gauge 51 , thereby ensuring the stability of the pressure during the production process and further ensuring the stable operation of the system.

[0073] Please continue reading Figure 1 The tar removal unit 3 is used to remove tar and hydrogen cyanide from the tail gas. The upper portion of the tar removal unit 3 is provided with an exhaust gas outlet and a solvent inlet. The lower portion of the tar removal unit 3 is provided with a tail gas inlet and a liquid outlet. The tail gas inlet is connected to the gas outlet of the gas-liquid separation mechanism 5. The tar removal unit 3 can utilize a circulation tank, etc., which is conventional technology and will not be described in detail here.

[0074] The principle of the tail gas treatment system of this embodiment is as follows: by configuring the heat exchanger 1 to be provided with a tail gas inlet and a gas inlet, the carbonized tail gas (containing hydrogen cyanide, ammonia and tar) in the carbon fiber production with a relatively high temperature and auxiliary gases such as nitrogen at a low temperature can be introduced into the heat exchanger 1. In the heat exchanger 1, the carbonized tail gas (containing hydrogen cyanide, ammonia and tar) in the carbon fiber production is exchanged with auxiliary gases such as nitrogen, thereby reducing the tail gas temperature. The tar in the tail gas condenses after cooling and is removed from the tail gas; then, it enters the gas-liquid separation mechanism 5 under the action of gravity and is separated from part of the tail gas and liquid entrained in the tar; then, the tar after gas removal is sent to the tar removal device 3. In the tar removal device 3, the solvent (such as benzene, toluene, acetic acid, ethanol, etc.) can dissolve and absorb tar with a relatively high viscosity at a low temperature and substances such as hydrogen cyanide, thereby removing tar, hydrogen cyanide, and other substances from the tail gas.

[0075] Example 2

[0076] See also Figure 2 , Figure 2 This is a schematic structural diagram of the exhaust gas treatment system shown in this embodiment.

[0077] Please continue reading Figure 2 This embodiment differs from Example 1 in that it further includes a deamination reactor 4, which is connected to the exhaust gas outlet of the tar removal unit 3. The deamination reactor 4 is used to remove ammonia from the exhaust gas treated by the tar removal unit 3. An acid inlet is provided at the top of the deamination reactor 4, and a first spray assembly (not shown) is provided at the top of the deamination reactor 4, which is connected to the acid inlet. An exhaust gas inlet and a liquid phase outlet are provided at the bottom of the deamination reactor 4, and the exhaust gas inlet of the deamination reactor 4 is connected to the exhaust gas outlet of the tar removal unit 3. A packing section 41 and a tray section 42 are sequentially provided between the acid inlet and the liquid phase outlet. The tray section 42 is provided with several sieve plates 421 located on the sidewalls from top to bottom. The deamination reactor 4 is provided with a liquid level gauge 43, and the liquid phase outlet is electrically connected to the liquid level gauge 43. The deamination reactor 4 can be an absorption tower, etc., which is a conventional technology and will not be described in detail here. In the deamination reactor 4 , substances such as ammonia contained in the tail gas react with substances such as dilute sulfuric acid entering the deamination reactor 4 from the acid liquid inlet, thereby removing ammonia from the tail gas.

[0078] Specifically, this embodiment adds a deamination reactor 4 connected to the exhaust gas outlet, and configures the deamination reactor 4 to have an acid inlet. Dilute sulfuric acid or other substances that can react with ammonia in the exhaust gas can be introduced into the deamination reactor 4 through the acid inlet, thereby removing ammonia from the exhaust gas. A packing section 41 and a tray section 42 are sequentially arranged between the acid inlet and the liquid phase outlet of the deamination reactor 4. The tray section 42 is provided with a plurality of sieve plates 421 located on the side walls from top to bottom. The packing ensures the absorption effect of the exhaust gas, and the plurality of sieve plates 421 located on the side walls from top to bottom of the tray section 42 prevent the extremely small amount of tar contained in the exhaust gas from clogging the deamination reactor 4, thereby ensuring smooth production. By configuring the deamination reactor 4 to have a liquid level gauge 43, and electrically connecting the liquid phase outlet to the liquid level gauge 43, the material in the deamination reactor 4 can be discharged in a timely manner when the liquid level reaches a certain level. By adding a first spray assembly to the top of the deamination reactor 4 and connecting the first spray assembly to the acid feed inlet, the contact area between dilute sulfuric acid and other substances and the exhaust gas generated in the carbonization process in carbon fiber production can be increased through the first spray assembly, thereby better removing ammonia and other substances in the exhaust gas.

[0079] Example 3

[0080] See also Figure 3 , Figure 3 This is a schematic structural diagram of the exhaust gas treatment system shown in this embodiment.

[0081] Please continue reading Figure 3 The difference between this embodiment and embodiment 2 is that it further includes an induced draft fan 2, which is located on the connecting pipe between the exhaust gas inlet and the gas outlet.

[0082] Specifically, this embodiment adds an induced draft fan 2 to the connecting pipe between the exhaust gas inlet and the gas outlet, so that the exhaust gas containing a small amount of tar can be extracted by the induced draft fan 2 and sent into the tar removal device 3, providing power for the exhaust gas, and then providing sufficient exhaust gas supply to the tar removal device 3, thereby improving the processing efficiency.

[0083] Example 4

[0084] See also Figure 4 , Figure 4 This is a schematic structural diagram of the exhaust gas treatment system shown in this embodiment.

[0085] See also Figure 4 The difference between this embodiment and embodiment 3 is that it further includes a pressure control valve 6, which is located on the connecting pipe between the gas outlet and the induced draft fan 2.

[0086] Specifically, this embodiment adds a pressure control valve 6 to the connecting pipe between the gas outlet and the induced draft fan 2, so that the pressure of the gas discharged from the gas-liquid separation mechanism 2 can be adjusted through the pressure control valve 6, thereby further ensuring the stability of the pressure during the production process, and further ensuring the stable operation of the system.

[0087] Example 5

[0088] See also Figure 5 , Figure 5 This is a schematic structural diagram of the exhaust gas treatment system shown in this embodiment.

[0089] See also Figure 5 This embodiment differs from Embodiment 4 in that it further includes a gas mixer 7, which is located in the communication conduit between the induced draft fan 2 and the exhaust gas inlet. The gas mixer 7 is provided with a circulation inlet, which is connected to the liquid outlet of the tar removal device 3. A circulation pump 8 is provided in the communication conduit between the circulation inlet of the gas mixer 7 and the liquid outlet of the tar removal device 3. A cooling mechanism 11 is provided in the communication conduit between the circulation pump 8 and the gas mixer 7. The cooling mechanism 11 can be a circulating cooler, which is conventional and will not be described in detail here. All communication conduits are equipped with on / off valves.

[0090] Specifically, this embodiment adds a gas mixer 7 to the connecting pipe between the induced draft fan 2 and the exhaust gas inlet, connects the liquid outlet to the circulation inlet of the gas mixer 7, and sets a circulation pump 8 on the connecting pipe between the liquid outlet and the circulation inlet of the gas mixer 7. The circulation pump 8 can send the tar with a small amount of gas into the cooling mechanism 11. The cooling mechanism 11 can reduce the temperature of the tar with a small amount of gas. After cooling, the tar condenses, so that part of the tar is separated from the exhaust gas and liquid. After separation, the exhaust gas carrying a small amount of tar enters the gas mixer 7, is evenly mixed with the exhaust gas pumped by the induced draft fan 2, and then enters the tar removal device 3 again for detaring treatment, thereby further recovering the tar.

[0091] Example 6

[0092] See also Figure 6 , Figure 6 This is a schematic structural diagram of the exhaust gas treatment system shown in this embodiment.

[0093] See also Figure 6This embodiment differs from Example 5 in that it further includes a tar removal mechanism 9 and / or a hydrocyanic acid removal device 10. These are connected to the tar outlet and / or the circulation pump 8. The hydrocyanic acid removal device 10 is provided with a hydrogen cyanide outlet and a solvent outlet, and the hydrogen cyanide outlet is connected to a hydroxyacetonitrile reactor 12. The solvent removal device 9 and the hydrocyanic acid removal device 10 can be implemented as a distillation column, for example, and the hydroxyacetonitrile reactor 12 can be implemented as a falling film reactor, for example. These distillation columns and falling film reactors are conventional technologies and will not be described in detail herein.

[0094] Specifically, this embodiment adds a tar removal mechanism 9 and / or a hydrocyanic acid removal device 10, and connects the tar removal mechanism 9 and / or the hydrocyanic acid removal device 10 to the tar outlet and / or the circulation pump 8. The hydrocyanic acid removal device is connected to a hydroxyacetonitrile reactor 12. The solvent and hydrogen cyanide entrained in the tar can be removed by the tar removal mechanism 9, and the hydrogen cyanide gas in the mixed gas can be removed by the hydrocyanic acid removal device 10. The removed hydrogen cyanide gas is fed into the hydroxyacetonitrile reactor 12, and hydroxyacetonitrile is produced using hydrogen cyanide gas as a raw material, thereby improving the resource utilization rate of hydrogen cyanide while improving the purity of the tar and improving the economic benefits.

[0095] Example 7

[0096] See also Figure 7 , Figure 7 This is a schematic structural diagram of the exhaust gas treatment system shown in this embodiment.

[0097] See also Figure 7 The difference between this embodiment and embodiment 6 is that the solvent outlet is connected to the tar removal device 3.

[0098] Specifically, this embodiment connects the solvent outlet of the hydrogen cyanide removal device 10 with the tar removal device 3, so that the solvent separated from the hydrogen cyanide removal device 10 can be sent to the tar removal device 3, thereby recycling the solvent, reducing production costs and increasing profits.

[0099] Without being limited thereto, another embodiment of the present invention further provides a carbon fiber production system, which includes the exhaust gas treatment system as described above.

[0100] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed in the present invention are intended to be covered by the claims of the present invention.

Claims

1. An exhaust gas treatment system, characterized in that: The tail gas treatment system includes: The heat exchanger has an exhaust gas inlet and outlet at the top and a gas inlet and material outlet at the bottom; a gas-liquid separation mechanism, provided with a feed inlet and a gas outlet, wherein the feed inlet is connected to the material outlet, and the gas-liquid separation mechanism is located below the heat exchanger; and The tar removal device is provided with a waste gas outlet and a solvent inlet at the top, and a tail gas inlet and a liquid outlet at the bottom, wherein the tail gas inlet is connected to the gas outlet.

2. The exhaust gas treatment system according to claim 1, characterized in that: The tail gas inlet is connected to a main pipeline, and the main pipeline is connected to a first branch pipeline and a second branch pipeline.

3. The exhaust gas treatment system according to claim 1, characterized in that: It also includes a deamination reactor, which is connected to the exhaust gas outlet and is provided with an acid liquid inlet.

4. The exhaust gas treatment system according to claim 1, characterized in that: The gas-liquid separation mechanism is provided with a pressure gauge.

5. The exhaust gas treatment system according to claim 1, wherein: It also includes an induced draft fan, which is located on the communication pipe between the exhaust gas inlet and the gas outlet.

6. The exhaust gas treatment system according to claim 5, characterized in that: It also includes a pressure control valve, which is located on the communication pipe between the gas outlet and the induced draft fan.

7. The exhaust gas treatment system according to claim 5, characterized in that: It also includes a gas mixer, which is located on the connecting pipe between the induced draft fan and the exhaust gas inlet. The gas mixer is provided with a circulation inlet, which is connected to the liquid outlet. A circulation pump is provided on the connecting pipe between the circulation inlet and the liquid outlet, and a cooling mechanism is provided on the connecting pipe between the circulation pump and the gas mixer.

8. The exhaust gas treatment system according to claim 7, characterized in that: It also includes a tar removal mechanism and / or a hydrocyanic acid removal device, wherein the tar removal mechanism and / or the hydrocyanic acid removal device are connected to the tar outlet and / or the circulation pump, and the hydrocyanic acid removal device is provided with a hydrogen cyanide outlet, which is connected to a hydroxyacetonitrile reactor.

9. The exhaust gas treatment system according to claim 8, characterized in that: The hydrocyanic acid removal device is provided with a solvent outlet, and the solvent outlet is connected to the tar removal device.

10. A carbon fiber production system, characterized in that: The exhaust gas treatment system comprises the exhaust gas treatment system according to any one of claims 1 to 9.

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