Hydrogen-nitrogen mixed gas recycling device for oriented silicon steel decarburization and annealing line

Abstract

The invention relates to the technical field of gas treatment in the ferrous metallurgy industry, in particular to a hydrogen-nitrogen mixed gas recycling device for an oriented silicon steel decarburization annealing line. According to the technical scheme, the hydrogen-nitrogen mixed gas recycling device for the oriented silicon steel decarburization and annealing line comprises a recycling device body, a gas inlet treatment unit, an impurity treatment assembly, a discharging unit, a catalytic reaction pipeline and a catalyst spray head, and the gas inlet treatment unit is arranged on one side of the interior of the recycling device body; according to the invention, the noble metal catalyst is added at the gas discharge end, so that efficient purification and cyclic utilization of the hydrogen-nitrogen mixed gas are realized. A catalytic reaction pipeline and a catalyst spray head are integrated in the discharge unit, carbon monoxide and residual oxygen in mixed gas are converted into carbon dioxide and water, the problem that chemical impurities in the gas are not thoroughly removed is effectively solved, high-temperature or complex chemical reactions are not needed, and the treatment efficiency and the gas purity are improved.

Description

Technical Field

[0001] This invention relates to the field of gas treatment technology in the iron and steel metallurgical industry, and in particular to a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel. Background Technology

[0002] In the production process of grain-oriented silicon steel, decarburization annealing is one of the key processes. Usually, a mixture of hydrogen and nitrogen is introduced into the continuous annealing line as a protective atmosphere and a reaction atmosphere.

[0003] Existing hydrogen-nitrogen mixed gas recycling devices have insufficient capacity to handle impurities in the mixed gas during the gas purification stage, especially limited effectiveness in removing carbon monoxide and trace amounts of oxygen. This results in the gas purity failing to meet the requirements of efficient decarburization annealing. During the annealing process, if carbon monoxide and residual oxygen are not effectively removed, they will undergo side reactions with hydrogen, not only reducing the effective concentration of hydrogen but also potentially generating water or carbon dioxide, affecting the decarburization effect on the silicon steel surface, and even leading to product oxidation or performance degradation.

[0004] To address the aforementioned issues, this solution incorporates a precious metal catalyst at the gas emission end, achieving efficient purification and recycling of the hydrogen-nitrogen mixture. By integrating a catalytic reaction pipeline and catalyst nozzle into the emission unit, carbon monoxide and residual oxygen in the mixture are converted into carbon dioxide and water, effectively solving the problem of incomplete removal of chemical impurities from the gas. This solution eliminates the need for high temperatures or complex chemical reactions, thereby improving processing efficiency and gas purity. Summary of the Invention

[0005] To overcome the shortcomings of existing hydrogen-nitrogen mixed gas recycling devices in the gas purification stage, which have insufficient capacity to handle impurities in the mixed gas, especially the limited removal effect of carbon monoxide and trace oxygen, resulting in gas purity that cannot meet the requirements of efficient decarburization annealing, and the fact that carbon monoxide and residual oxygen, if not effectively removed during the annealing process, will undergo side reactions with hydrogen, not only reducing the effective concentration of hydrogen, but also potentially generating water or carbon dioxide, affecting the decarburization effect on the silicon steel surface, and even leading to product oxidation or performance degradation.

[0006] The technical solution of the present invention is as follows: a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel, comprising a recycling device body, an air intake treatment unit, an impurity treatment component, an emission unit, a catalytic reaction pipeline, and a catalyst nozzle. The air intake treatment unit is arranged on one side inside the recycling device body, the impurity treatment component is arranged below the air intake treatment unit, the emission unit is arranged on one side of the air intake treatment unit, the catalytic reaction pipeline is arranged inside the emission unit, and the catalyst nozzle is arranged at the end of the catalytic pipeline. Multiple sets of catalyst nozzles are arranged.

[0007] Preferably, the hydrogen-nitrogen mixture entering the main body of the recycling unit undergoes preliminary treatment via an intake treatment unit, particulate impurities are removed from the mixture via an impurity treatment component, and final treatment is performed via an emission unit before being output. A precious metal catalyst is then transported through a catalytic reaction pipeline and sprayed through a catalyst nozzle, mixing it with the hydrogen-nitrogen mixture entering the emission unit. This process neutralizes CO and residual CO in the exhaust gas. and A catalytic reaction occurs at low temperatures, transforming into... and .

[0008] Preferably, the emission unit is equipped with an exhaust fan located directly below the catalyst nozzle, and an emission port is provided on one side of the emission unit. A conveying pipe is provided at the bottom of one side of the main body of the recycling device, and a conveying valve is provided on the outside of the conveying pipe.

[0009] Preferably, the top surface of the air intake treatment unit is provided with an air guide plate, the inside of the air intake treatment unit is provided with an installation frame, the upper layer of the installation frame is provided with a molecular sieve adsorbent layer, and the lower layer of the installation frame is provided with a special deoxidizer layer.

[0010] Preferably, the impurity treatment component includes a support frame, a cyclone separator, a collection basket, a guide channel, and a flow channel. The support frame is located below the air intake treatment unit, the cyclone separator is located inside the support frame, the guide channel is located at the bottom of the support frame, the collection basket is located directly below the guide channel, and the flow channel is located on one side of the support frame, with one end of the flow channel connected to the emission unit.

[0011] Preferably, the top surface of the emission unit is provided with a first connecting hinge, and one side of the first connecting hinge is provided with an observation cover plate, the surface of which is provided with a fixing buckle.

[0012] Preferably, a second connecting hinge is provided on one side of the air intake treatment unit, and an inspection door is provided on one side of the second connecting hinge.

[0013] Preferably, anti-slip pads are provided at all four corners of the bottom surface of the main body of the recycling device.

[0014] The beneficial effects of this invention are: Existing hydrogen-nitrogen mixed gas recycling devices have insufficient capacity to handle impurities in the gas mixture during the gas purification stage, especially limited effectiveness in removing carbon monoxide and trace amounts of oxygen. This results in gas purity that cannot meet the requirements of efficient decarburization annealing. During annealing, if carbon monoxide and residual oxygen are not effectively removed, they will undergo side reactions with hydrogen, not only reducing the effective concentration of hydrogen but also potentially generating water or carbon dioxide, affecting the decarburization effect on the silicon steel surface and even leading to product oxidation or performance degradation. This solution achieves efficient purification and recycling of the hydrogen-nitrogen mixed gas by adding a precious metal catalyst at the gas emission end. The catalytic reaction pipeline and catalyst nozzle are integrated into the emission unit to convert carbon monoxide and residual oxygen in the mixed gas into carbon dioxide and water, effectively solving the problem of incomplete removal of chemical impurities in the gas. This solution eliminates the need for high temperatures or complex chemical reactions, improving processing efficiency and gas purity. Attached Figure Description

[0015] Figure 1 The diagram shown is a first three-dimensional structural schematic of a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel according to the present invention. Figure 2 The diagram shown is a second three-dimensional structural schematic of a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel according to the present invention. Figure 3 The diagram shown is a three-dimensional structural illustration of the internal structure of a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel according to the present invention. Figure 4 The diagram shown is a three-dimensional structural schematic of the emission unit of a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel according to the present invention. Figure 5 The diagram shown is a partial three-dimensional structural schematic of a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel according to the present invention. Figure 6 The diagram shown is a three-dimensional structural schematic of the impurity treatment component of a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel according to the present invention. Explanation of reference numerals in the attached drawings: 1. Main body of the recycling device; 201. Air intake treatment unit; 202. Air guide plate; 203. Mounting frame; 204. Molecular sieve adsorbent layer; 205. Special deoxidizer layer; 301. Support frame; 302. Cyclone separator; 303. Collection basket; 304. Guide channel; 305. Flow channel; 401. Discharge unit; 402. Discharge port; 403. Exhaust fan; 404. Catalytic reaction pipeline; 405. Catalyst nozzle; 406. Conveying pipeline; 407. Conveying valve; 501. First connecting hinge; 502. Observation cover; 503. Fixing latch; 601. Second connecting hinge; 602. Inspection door; 7. Anti-slip pad. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Please see Figure 4 This invention provides an embodiment of a hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of oriented silicon steel, comprising a recycling device body 1, an air intake treatment unit 201, an impurity treatment component, an emission unit 401, a catalytic reaction pipeline 404, and a catalyst nozzle 405. The air intake treatment unit 201 is disposed on one side inside the recycling device body 1, and the impurity treatment component is disposed below the air intake treatment unit 201. The emission unit 401 is disposed on one side of the air intake treatment unit 201, and the catalytic reaction pipeline 404 is disposed inside the emission unit 401. A catalyst nozzle 405 is disposed at the end of the catalytic pipeline 401, and multiple sets of catalyst nozzles 405 are provided.

[0018] Preferably, the hydrogen-nitrogen mixture entering the main body 1 of the recycling device undergoes preliminary treatment via the intake treatment unit 201, particulate impurities in the hydrogen-nitrogen mixture are removed via the impurity treatment component, and the hydrogen-nitrogen mixture undergoes final treatment via the emission unit 401 before being output. A precious metal catalyst is transported via the catalytic reaction pipeline 404 and sprayed via the catalyst nozzle 405, mixing it with the hydrogen-nitrogen mixture entering the emission unit 401, thereby reducing the CO and residual CO in the exhaust gas. and A catalytic reaction occurs at low temperatures, transforming into... and .

[0019] The precious metal catalyst can be either a platinum-based catalyst or a palladium-based catalyst. Platinum-based catalysts have good low-temperature activity and strong resistance to poisoning, while palladium-based catalysts have relatively low cost and are suitable for medium and low temperature catalysis. Operators can choose the catalyst according to the actual operation conditions.

[0020] Please see Figure 1 and Figure 4 In this embodiment, an exhaust fan 403 is provided inside the emission unit 401, which is located directly below the catalyst nozzle 405. An emission port 402 is provided on one side of the emission unit 401. A conveying pipe 406 is provided at the bottom of one side of the recycling device body 1, and a conveying valve 407 is provided on the outside of the conveying pipe 406. In use, the exhaust fan 403 drives the hydrogen-nitrogen mixture that has been finally processed in the emission unit 401 to flow, and the processed hydrogen-nitrogen mixture is discharged through the emission port 402. The conveying pipe 406 connects the recycling device body 1 to the precious metal catalyst storage device, and the conveying valve 407 controls the conveying rate of the precious metal catalyst.

[0021] Please see Figure 5 In this embodiment, an air guide plate 202 is provided on the top surface of the air intake treatment unit 201, and an installation frame 203 is provided inside the air intake treatment unit 201. A molecular sieve adsorbent layer 204 is provided on the upper layer inside the installation frame 203, and a special deoxidizer layer 205 is provided on the lower layer inside the installation frame 203. In use, the air intake treatment unit 201 is connected to the gas transmission equipment through the air guide plate 202, and the molecular sieve adsorbent layer 204 and the special deoxidizer layer 205 are installed through the installation frame 203. The molecular sieve adsorbent layer 204 deeply removes moisture and carbon dioxide from the gas, and the special deoxidizer layer 205 removes residual trace oxygen.

[0022] Please see Figure 5 and Figure 6 In this embodiment, the impurity treatment component includes a support frame 301, a cyclone separator 302, a collection basket 303, a guide channel 304, and a flow channel 305. The support frame 301 is located below the air intake treatment unit 201. The cyclone separator 302 is located inside the support frame 301. The guide channel 304 is located at the bottom of the support frame 301. The collection basket 303 is located directly below the guide channel 304. The flow channel 305 is located on one side of the support frame 301. One end of the flow channel 305 is connected to the emission unit 401. In use, the cyclone separator 302 is installed through the support frame 301. The cyclone separator 302 further separates particulate impurities in the hydrogen-nitrogen mixture. The separated particulate impurities are guided into the collection basket 303 through the guide channel 304. The pre-treated air is transported into the emission unit 401 through the flow channel 305.

[0023] Please see Figure 1 In this embodiment, the top surface of the emission unit 401 is provided with a first connecting hinge 501, and an observation cover 502 is provided on one side of the first connecting hinge 501. The surface of the observation cover 502 is provided with a fixing buckle 503. In use, the observation cover 502 and the emission unit 401 are connected by the first connecting hinge 501, the emission unit 401 is sealed by the observation cover 502, and the observation cover 503 is fixed by the fixing buckle 503.

[0024] Please see Figure 2 In this embodiment, a second connecting hinge 601 is provided on one side of the air intake treatment unit 201, and an inspection door 602 is provided on one side of the second connecting hinge 601. In use, the inspection door 602 and the air intake treatment unit 201 are connected by the second connecting hinge 601, and the inspection door 602 facilitates maintenance personnel to perform maintenance on the inside of the air intake treatment unit 201.

[0025] Please see Figure 2 and Figure 3 In this embodiment, anti-slip pads 7 are provided at the four corners of the bottom surface of the recycling device body 1. During use, the anti-slip pads 7 prevent the recycling device body 1 from sliding.

[0026] Example 1 Background: During the production process of the continuous decarburization annealing furnace for grain-oriented silicon steel, a protective hydrogen-nitrogen mixture is introduced into the furnace to prevent steel strip oxidation and participate in the decarburization reaction. The exhaust gas discharged from the furnace tail contains unreacted... , In addition, it may contain CO generated during the reaction and residual trace amounts of [unspecified substance]. Water vapor In addition to trace particulate impurities carried out from the furnace, the waste gas needs to be purified and regenerated in order to achieve gas recycling, reduce fresh gas consumption, and ensure gas purity.

[0027] Implementation steps: The exhaust gas from the annealing furnace is delivered through an external gas pipeline and then via a gas guide plate 202 to the gas intake treatment unit 201 of the main body of the recycling device 1. The gas first passes through the molecular sieve adsorbent layer 204 on the upper layer of the mounting frame 203, where most of the moisture and carbon dioxide in the gas are deeply adsorbed and removed. Subsequently, the gas flows through the lower layer of dedicated deoxidizer 205, where the remaining trace amounts of oxygen are removed. The adsorbent / deoxidizer is chemically adsorbed and removed to prevent it from harming the quality of subsequent catalysts and steel strips. Maintenance personnel can periodically inspect or replace the adsorbent / deoxidizer through the inspection door 602 connected by the second connecting hinge 601.

[0028] After initial purification, the gas flows downward into the impurity treatment component. In the cyclone separator 302 fixed in the support frame 301, the gas rotates along a specific path, using centrifugal force to separate the tiny iron oxide particles and other solid impurities carried in the gas flow. The separated particles fall into the collection basket 303 at the bottom through the guide channel 304 for easy centralized cleaning. The purified gas then enters the next treatment stage through the guide channel 305.

[0029] Gas enters emission unit 401 through guide channel 305. At the same time, precious metal catalyst is introduced from external storage device through delivery pipe 406. Its flow rate is precisely controlled by delivery valve 407. The catalyst is delivered to catalyst nozzle 405 through catalytic reaction pipe 404. Multiple sets of catalyst nozzles 405 spray the catalyst evenly into the gas flow.

[0030] After thorough purification through the catalytic reaction, the purity of the hydrogen-nitrogen mixture was restored, and its main components returned to meet the process requirements. and Driven by the exhaust fan 403, the gas is discharged from the discharge port 402. After being pressurized by the circulating fan, it can be sent back to the decarburization annealing furnace as a protective gas.

[0031] Operators or maintenance personnel can open the observation cover 502, which is connected by the first connecting hinge 501 and fixed by the fixing buckle 503, to observe the catalytic reaction inside the emission unit 401.

[0032] Example 2 Background: In the grain-oriented silicon steel production workshop of a large steel enterprise, the continuous decarburization annealing furnace generates approximately 1500 standard cubic meters of waste gas per hour during operation. The main component of the waste gas is an unreacted hydrogen-nitrogen mixture, and it also contains reaction byproducts such as CO and trace amounts of residual gases. In order to achieve energy conservation, emission reduction, and lower production costs, the workshop decided to use the aforementioned hydrogen-nitrogen mixed gas recycling device to purify the waste gas, including moisture and trace amounts of iron oxide dust carried out from the furnace, so that it could meet the process requirements again and be returned to the production line for recycling.

[0033] Implementation steps: The main body 1 of the recycling device is securely installed on the equipment platform near the decarburization annealing furnace. The anti-slip pads 7 on the bottom of the device ensure that the device does not slide during operation. A special pipe is used to connect the exhaust port of the annealing furnace to the air guide plate 202 of the device. At the same time, the exhaust port 402 of the device is connected to the air inlet of the circulating fan through a pipe. The air outlet of the circulating fan is connected to the protective gas inlet of the decarburization annealing furnace. The precious metal catalyst storage tank is connected to the conveying pipe 406 of the device through a flexible pipe.

[0034] The high-temperature exhaust gas from the annealing furnace is first cooled to approximately 40-50°C by an external heat exchanger before entering the recycling unit. The exhaust gas first enters the intake treatment unit 201, where it flows through the molecular sieve adsorbent layer 204. Here, the moisture content in the exhaust gas is significantly reduced from approximately 1.5% to below 10 ppm, and the carbon dioxide content is reduced from approximately 0.3% to below 10 ppm. Subsequently, the gas passes through the dedicated deoxidizer layer 205, where residual trace amounts of oxygen are completely removed to below 1 ppm. During this stage, maintenance personnel can periodically check the saturation of the adsorbent and deoxidizer through the inspection door 602 and replace them as planned. After drying and deoxygenation, the exhaust gas flows downwards into the cyclone separator 302 inside the support frame 301 due to the system pressure difference. The exhaust gas rotates at high speed inside the separator, and the iron oxide particles it contains are thrown against the wall and separated under the action of centrifugal force. The separated dust particles fall into the collection basket 303 below through the guide channel 304. The operator needs to clean the collection basket once a week to ensure that the channel is unobstructed. The gas after removing particulate matter is smoothly transported to the emission unit 401 through the guide channel 305.

[0035] The gas entering the emission unit 401 has its main impurities converted to CO. At this time, the precious metal catalyst supply system is activated. By adjusting the delivery valve 407, a precisely metered liquid or gaseous precious metal catalyst is delivered through the delivery pipe 406 and the catalytic reaction pipe 404 to multiple sets of catalyst nozzles 405. The nozzles atomize the catalyst into micron-sized droplets, which are then evenly sprayed into the gas stream. Simultaneously, the exhaust fan 403 is activated. The fan's agitation action ensures that the catalyst and gas are fully and rapidly mixed. Under the action of the catalyst, the CO in the exhaust gas reacts with the residual... A catalytic oxidation / conversion reaction occurs at a low temperature of 60-80℃, producing... and Through this process, the CO concentration can be reduced from hundreds of ppm to below 10 ppm, fully meeting the requirements for reuse.

[0036] The gas, after being thoroughly purified by the catalytic reaction, has had its composition restored to [a certain state]. and The high-purity protective gas, driven by the exhaust fan 403, is stably discharged from the exhaust port 402. After being pressurized by the circulating fan, it is sent back into the furnace of the decarburization annealing furnace, forming a complete closed-loop cycle. During operation, the operator can open the observation cover 502 and use the built-in observation window or portable detection instrument to check the internal reaction status of the emission unit 401 and the catalyst spraying effect.

[0037] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of grain-oriented silicon steel, comprising a recycling device body (1), characterized in that: It also includes an air intake treatment unit (201), an impurity treatment component, an emission unit (401), a catalytic reaction pipeline (404), and a catalyst nozzle (405). An air intake treatment unit (201) is provided on one side of the main body (1) of the recycling device. An impurity treatment component is provided below the air intake treatment unit (201). An emission unit (401) is provided on one side of the air intake treatment unit (201). A catalytic reaction pipeline (404) is provided inside the emission unit (401). A catalyst nozzle (405) is provided at the end of the catalytic pipeline (401). Multiple sets of catalyst nozzles (405) are provided.

2. The hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of grain-oriented silicon steel according to claim 1, characterized in that: An exhaust fan (403) is installed inside the emission unit (401). The exhaust fan (403) is located directly below the catalyst nozzle (405). An emission port (402) is provided on one side of the emission unit (401). A conveying pipe (406) is provided at the bottom of one side of the main body (1) of the recycling device. A conveying valve (407) is provided on the outside of the conveying pipe (406).

3. The hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of grain-oriented silicon steel according to claim 1, characterized in that: An air guide plate (202) is provided on the top surface of the air intake treatment unit (201), and an installation frame (203) is provided inside the air intake treatment unit (201). A molecular sieve adsorbent layer (204) is provided in the upper part of the installation frame (203), and a special deoxidizer layer (205) is provided in the lower part of the installation frame (203).

4. The hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of grain-oriented silicon steel according to claim 1, characterized in that: The impurity treatment component includes a support frame (301), a cyclone separator (302), a collection basket (303), a guide channel (304), and a flow channel (305). The support frame (301) is located below the air intake treatment unit (201). The cyclone separator (302) is located inside the support frame (301). The guide channel (304) is located at the bottom of the support frame (301). The collection basket (303) is located directly below the guide channel (304). The flow channel (305) is located on one side of the support frame (301). One end of the flow channel (305) is connected to the emission unit (401).

5. The hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of grain-oriented silicon steel according to claim 2, characterized in that: The top surface of the emission unit (401) is provided with a first connecting hinge (501), and an observation cover (502) is provided on one side of the first connecting hinge (501). A fixing buckle (503) is provided on the surface of the observation cover (502).

6. The hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of grain-oriented silicon steel according to claim 1, characterized in that: A second connecting hinge (601) is provided on one side of the air intake treatment unit (201), and an inspection door (602) is provided on one side of the second connecting hinge (601).

7. The hydrogen-nitrogen mixed gas recycling device for a decarburization annealing line of grain-oriented silicon steel according to claim 1, characterized in that: Anti-slip pads (7) are provided at the four corners of the bottom surface of the main body (1) of the recycling device.

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