Blast furnace gas damping down, reblowing and diffusing recovery treatment system

Abstract

The utility model provides a blast furnace gas damping-down, reblowing and diffusing recovery processing system which comprises a first recovery pipeline, a second recovery pipeline and a third recovery pipeline. The two ends of the first recovery pipeline are connected with a blast furnace top and a high-pressure clean gas pipeline respectively; two ends of the second recovery pipeline are respectively connected with the blast furnace top and the low-pressure clean gas pipe network; the first dust remover group is arranged on the first recovery pipeline; the second dust remover group is arranged on the second recovery pipeline; the two ends of the collecting pipeline are connected with the first recycling pipeline and the second recycling pipeline respectively, the joint of the collecting pipeline and the first recycling pipeline is located at the downstream of the first dust remover set, the joint of the collecting pipeline and the second recycling pipeline is located at the downstream of the second dust remover set, and the collecting pipeline is provided with a first valve set which is opened when the blast furnace is in the blowing-down and reblowing process; and the at least one ejector is arranged on the first recovery pipeline and / or the second recovery pipeline and used for being started when the blast furnace stops and reblows. Gas and smoke entering the atmosphere in the blowing-down and reblowing process of the blast furnace are reduced to the maximum extent, pollution is reduced, and environment-friendly production is achieved.

Description

Technical Field

[0001] This application belongs to the field of blast furnace gas venting and recovery technology, and specifically relates to a blast furnace gas shutdown and restart venting and recovery system. Background Technology

[0002] Blast furnace shutdown and blast furnace restart are blast furnace operation methods for temporarily stopping and subsequently resuming blast furnace production. The basic operations for stopping and resuming blast furnace production are stopping the supply of air into the furnace and resuming the supply of air into the furnace.

[0003] Blast furnaces generate significant amounts of gas and dust emissions during production, shutdowns, and restarts. These emissions primarily consist of gas used for equalizing pressure in the charging tanks, gas from shutdowns during maintenance, and substandard gas from restarts. This gas is characterized by large volumes, high dust content, and numerous harmful gas components, severely polluting the atmosphere, producing visually a dense cloud of black smoke, generating significant noise, and wasting valuable energy. In recent years, both ultra-low emission requirements and the internal "Environmental Protection Standards" requirements for steel enterprises have spurred them to pursue green and sustainable development.

[0004] With the increasing maturity of blast furnace top pressure equalization venting and recovery technology, blast furnace gas recovery and purification has become widespread in steel enterprises. However, the treatment of blast furnace gas venting and recovery during shutdowns and restarts is rarely addressed. Therefore, improving the treatment of blast furnace gas venting and recovery during shutdowns and restarts is an urgent problem to be solved. Utility Model Content

[0005] To address the aforementioned technical problems in the prior art, this application provides a blast furnace gas shutdown and restart venting recovery and treatment system.

[0006] The technical solution adopted in this application embodiment is: a blast furnace gas shutdown and restart venting recovery and treatment system, comprising:

[0007] The first recovery pipeline is connected at one end to the first position on the top of the blast furnace and at the other end to the high-pressure clean gas pipeline.

[0008] The second recovery pipeline has one end connected to a second position on the top of the blast furnace and the other end connected to a low-pressure clean gas pipeline. The second position is located below the first position.

[0009] The first dust collector group is located on the first recovery pipeline and is used to remove dust from the blast furnace gas entering the first recovery pipeline.

[0010] The second dust collector unit is located on the second recovery pipeline and is used to remove dust from the blast furnace gas entering the second recovery pipeline.

[0011] A collection pipeline is provided, with one end connected to the first recovery pipeline and the other end connected to the second recovery pipeline. The connection point between the collection pipeline and the first recovery pipeline is located downstream of the first dust collector group, and the connection point between the collection pipeline and the second recovery pipeline is located downstream of the second dust collector group. A first valve group is provided on the collection pipeline. The first valve group is used to open when the blast furnace is in the process of shutdown and restart, so that the gas after dust removal by the first dust collector group can be collected into the low-pressure clean gas pipeline network.

[0012] At least one ejector is provided on the first recovery pipeline and / or the second recovery pipeline for opening when the blast furnace is in the process of shutting down and restarting, so as to quickly introduce the gas in the blast furnace into the first recovery pipeline and / or the second recovery pipeline for recovery or venting after dust removal.

[0013] In an optional embodiment, the second recovery pipeline is further provided with a second valve group, which is located upstream of the second dust collector group. The second valve group is used to open when the blast furnace is in the process of shutdown and restart, so that the gas in the blast furnace enters the second recovery pipeline, and after being dusted by the second dust collector group and meeting the recovery conditions, it enters the low-pressure clean gas pipeline network.

[0014] In an optional embodiment, the blast furnace gas shutdown and restart venting and recovery system further includes a controller and a gas analyzer and a venting pipe installed on the second recovery pipeline. The gas analyzer and the venting pipe are both located downstream of the second dust collector group, and the gas analyzer is located upstream of the venting pipe. The gas analyzer is located upstream of the connection between the collecting pipeline and the second recovery pipeline, and the venting pipe is located upstream of the connection between the collecting pipeline and the second recovery pipeline. The venting pipe is equipped with an on / off valve.

[0015] The gas analyzer is used to detect the oxygen content in the dust-removed coal gas, and generates a first signal when the oxygen content is lower than a preset value, and generates a second signal when the oxygen content is higher than the preset value.

[0016] The controller is electrically connected to the gas analyzer and the on / off valve respectively. When the controller receives the first signal, it controls the first valve group to close and controls the on / off valve to open so that the dust-removed coal gas can be released through the vent pipe. When the controller receives the second signal, it controls the first valve group to open and controls the on / off valve to close so that the dust-removed coal gas can be recycled into the low-pressure clean coal gas pipeline network.

[0017] In an optional embodiment, at least one ejector includes a pre-ejector and a post-ejector, the pre-ejector being located upstream of the second dust collector group, and the post-ejector being located downstream of the connection between the collecting pipeline and the second recovery pipeline, and upstream of the connection between the vent pipe and the second recovery pipeline.

[0018] In an optional embodiment, a check valve is also provided on the second recovery pipeline. The check valve is located downstream of the gas analyzer and upstream of the connection between the collection pipeline and the second recovery pipeline.

[0019] In an optional embodiment, the second recovery pipeline is further provided with a recovery valve, which is located downstream of the vent pipe and is used to control the dust-removed coal gas to enter the low-pressure clean coal gas pipeline network.

[0020] In an optional embodiment, the first dust collector group includes a first gravity dust collector and a plurality of first bag dust collectors connected in series. The first gravity dust collector is located upstream of the plurality of first bag dust collectors. During the blast furnace shutdown process, the plurality of first bag dust collectors are closed one by one, and during the blast furnace restart process, the plurality of first bag dust collectors are opened one by one. The first gravity dust collector is a gravity dust collector used for dust removal of blast furnace top gas during blast furnace production. The plurality of first bag dust collectors are all dry dust collection boxes used for dust removal of blast furnace top gas during blast furnace production.

[0021] In an optional embodiment, at least one of the ejectors further includes a recirculation ejector, which is disposed on the dry dust removal box on the first recovery pipeline. The recirculation ejector is used to quickly introduce the flue gas in the blast furnace into the first recovery pipeline for dust removal and then release when the blast furnace is in the recirculation process.

[0022] In an optional embodiment, the second dust collector group includes a second gravity dust collector and a second bag filter dust collector. The second gravity dust collector is located upstream of the second bag filter dust collector. The second gravity dust collector is a gravity dust collector used to remove dust from the material hopper at the top of the blast furnace during the blast furnace production process. The second bag filter dust collector is a pressure equalization dust collection box used to remove dust from the material hopper at the top of the blast furnace during the blast furnace production process.

[0023] In an optional embodiment, both the first valve group and the second valve group include at least a butterfly valve and a blind valve connected in series.

[0024] Compared with the prior art, the beneficial effects of the embodiments of this application are as follows: This application achieves effective treatment of gas during the shutdown and restart process of the blast furnace by making full use of the existing dust collectors in the original blast furnace production process on the existing site, thereby minimizing the entry of gas and dust into the atmosphere, reducing air pollution, and achieving environmentally friendly production.

[0025] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and are not intended to limit this application.

[0026] The overview of various implementations or examples of the technology described in this application is not a full disclosure of the entire scope or all features of the disclosed technology. Attached Figure Description

[0027] In drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The drawings generally illustrate various embodiments by way of example rather than limitation and are used, together with the description and claims, to illustrate the disclosed embodiments. Where appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts. Such embodiments are illustrative and not intended to be exhaustive or exclusive embodiments of the apparatus or method.

[0028] Figure 1 This is a schematic diagram of a blast furnace gas shutdown and restart venting and recovery system according to an embodiment of this application. The arrows in the diagram indicate the flow direction of the gas.

[0029] Figure label:

[0030] 1-First recovery pipeline; 2-Second recovery pipeline; 3-Collection pipeline; 4-Pre-ejector; 5-Post-ejector; 6-First valve group; 7-Second valve group; 8-Third valve group; 9-First gravity dust collector; 10-First bag filter; 11-Second gravity dust collector; 12-Second bag filter; 13-Gas analyzer; 14-Vent pipe; 15-Check valve; 16-Recovery valve; 17-Return air ejector; 18-Blast furnace; 19-Furnace top riser pipe; 20-High-pressure clean gas pipeline; 21-Low-pressure clean gas pipeline network; 22-Material tank; 23-Furnace top vent valve. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the described embodiments of this application without creative effort are within the scope of protection of this application.

[0032] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] To keep the following description of the embodiments of this application clear and concise, detailed descriptions of known functions and known components are omitted.

[0034] This application provides a blast furnace gas shutdown and restart venting and recovery system (hereinafter referred to as the venting and recovery system) for venting or recovering the top gas of blast furnace 18 during shutdown and restart processes.

[0035] like Figure 1As shown, the venting and recovery system of this application embodiment includes a first recovery pipeline 1, a second recovery pipeline 2, a collecting pipeline 3, a first dust collector group, a second dust collector group, an ejector, and a first valve group 6. One end of the first recovery pipeline 1 is connected to a first position of the top riser pipe 19 of the blast furnace 18, and the other end is connected to a high-pressure clean gas pipeline 20. One end of the second recovery pipeline 2 is connected to a second position of the top riser pipe 19 of the blast furnace 18, and the other end is connected to a low-pressure clean gas pipeline network 21, wherein the second position is located below the first position. The first dust collector group is installed on the first recovery pipeline 1 and is used to remove dust from the blast furnace gas entering the first recovery pipeline 1. The second dust collector group is installed on the second recovery pipeline 2 and is used to remove dust from the blast furnace gas entering the second recovery pipeline 2. One end of the collecting pipeline 3 is connected to the first recovery pipeline 1, and the other end is connected to the second recovery pipeline 2. The connection point between the collecting pipeline 3 and the first recovery pipeline 1 is located downstream of the first dust collector group, and the connection point between the collecting pipeline 3 and the second recovery pipeline 2 is located downstream of the second dust collector group. Alternatively, one end of the collecting pipeline 3 can be understood as being connected to the high-pressure clean gas pipeline 20. The first valve group 6 is located on the collecting pipeline 3 and is used to open during the shutdown and restart processes of the blast furnace 18, so that the gas after dust removal by the first dust collector group flows into the low-pressure clean gas pipeline network 21. An ejector is located on the first recovery pipeline 1 and / or the second recovery pipeline 2 and is used to open during the shutdown and restart processes of the blast furnace 18, rapidly introducing the gas in the blast furnace 18 into the first recovery pipeline 1 and / or the second recovery pipeline 2 for dust removal and recovery or venting.

[0036] The venting and recovery system of this application embodiment, by setting up two parallel recovery pipelines, allows the gas to selectively flow through the first recovery pipeline 1 and / or the second recovery pipeline 2 according to the pressure inside the blast furnace top during the shutdown and restart of the blast furnace 18. After the gas is dedusted by the dust collector group, it is recovered or released according to the amount of gas and the oxygen content in the gas, thereby reducing the pollution caused by the direct release of gas with high dust content and avoiding the energy waste caused by the direct release of gas suitable for recovery.

[0037] The first dust collector group can adopt the dust collector used for dust removal of blast furnace gas during the production process of blast furnace 18. That is, blast furnace 18 shares the same dust collector during both production and shutdown / restart processes, thus saving equipment and reducing costs. During production, the main shut-off valve (not shown in the figure) on the high-pressure clean gas pipeline 20 is opened, and the first valve group 6 is closed. The gas from blast furnace 18 enters the first recovery pipeline 1, is dusted, and then directly enters the high-pressure clean gas pipeline 20. During shutdown / restart processes, when conditions are suitable, the first valve group 6 is opened, and the main shut-off valve is closed. The gas from blast furnace 18 enters the first recovery pipeline 1, is dusted, and then flows into the second recovery pipeline 2. If the recovery conditions are met, it enters the low-pressure clean gas pipeline network 21 for recovery; otherwise, it is vented.

[0038] The second gravity dust collector 11 can be the same dust collector used to remove dust from the material hopper 22 at the top of the blast furnace 18 during the production process. That is, the blast furnace 18 uses the same dust collector during the production process and the shutdown and restart processes, which can save equipment and reduce costs.

[0039] In some embodiments, continue to combine Figure 1 The second recovery pipeline 2 is also equipped with a second valve group 7, which is located upstream of the second dust collector group. That is, the second valve group 7 is located near the connection between the second recovery pipeline 2 and the furnace top riser pipe 19. The second valve group 7 is used to open when the blast furnace 18 is in the process of shutdown and restart, so that the gas from the furnace top riser pipe 19 enters the second recovery pipeline 2, and after being dusted by the second dust collector group and meeting the recovery conditions, it enters the low-pressure clean gas pipeline network 21.

[0040] For example, such as Figure 1 As shown, one end of the second recovery pipeline 2 splits into two branches. One branch connects to the wall of the furnace top riser pipe 19 and communicates with the interior of the furnace top riser pipe 19. The second valve group 7 is located on this branch. The other branch connects to the material tank 22 and communicates with the interior of the material tank 22. A third valve group 8 is located on this branch. During the production process of blast furnace 18, the second valve group 7 is closed and the third valve group 8 is opened. The dust in the material tank 22 enters the second recovery pipeline 2, is treated by dust removal, and is then recovered and reused. This process follows the original pressure equalization gas recovery process. During the shutdown and restart process of blast furnace 18, the second valve group 7 is opened and the third valve group 8 is closed. The gas from blast furnace 18 enters the second recovery pipeline 2 and is treated by dust removal. If the dust-removed gas meets the recovery conditions, it enters the low-pressure clean gas pipeline network 21 for recovery. If it does not meet the recovery conditions, it is released.

[0041] Whether the gas should undergo the recovery and purification process during shutdown and restart can be determined based on the pressure at the furnace top. For example, gas with a furnace top pressure within a certain threshold range is considered to meet the conditions for ejector recovery and purification, while gas with a furnace top pressure higher than a certain threshold follows the original natural recovery conditions. Alternatively, it can be determined based on the time elapsed between shutdown and restart of the blast furnace. For example, gas in the later stages of shutdown and the beginning stages of restart is considered to be undergoing the ejector recovery and purification process. Whether the gas can be recovered into the low-pressure pipeline can be determined using detection instruments.

[0042] In some embodiments, the venting and recovery system further includes a gas analyzer 13, which is used to detect the oxygen content in the dust-removed coal gas to determine whether the coal gas meets the recovery conditions. Specifically, such as Figure 1 As shown, the venting and recovery system also includes a controller (not shown) and a gas analyzer 13 and a vent pipe 14 installed on the second recovery pipeline 2. Both the gas analyzer 13 and the vent pipe 14 are located downstream of the second dust collector group, with the gas analyzer 13 located upstream of the vent pipe 14. The gas analyzer 13 is located upstream of the connection between the collecting pipeline 3 and the second recovery pipeline 2, and the vent pipe 14 is also located upstream of this connection. The vent pipe 14 is equipped with an on / off valve. The gas analyzer 13 is used to detect the oxygen content in the precipitated gas and generates a first signal when the oxygen content is lower than a preset value, and a second signal when the oxygen content is higher than the preset value. The controller is electrically connected to the gas analyzer 13 and the on / off valve. When the controller receives a first signal, it controls the first valve group 6 to close and the on / off valve to open, allowing the dust-removed coal gas to be released through the vent pipe 14. When the controller receives a second signal, it controls the first valve group 6 to open and the on / off valve to close, allowing the dust-removed coal gas to enter the low-pressure clean coal gas pipeline network 21 for recovery. By setting the gas analyzer 13, it is possible to accurately determine whether the coal gas meets the recovery conditions, and based on the determination result, the coal gas is either released through the vent pipe 14 or enters the low-pressure clean coal gas pipeline network 21 for recovery.

[0043] In an optional embodiment, continue to combine Figure 1 A check valve 15 is also installed on the second recovery pipeline 2. The check valve 15 is located downstream of the gas analyzer 13 and upstream of the connection between the collecting pipeline 3 and the second recovery pipeline 2. The check valve 15 can prevent the gas from the low-pressure clean gas pipeline 21 from flowing back into the second dust collector group and affecting the normal operation of the venting and recovery treatment system.

[0044] The second recovery pipeline 2 is also equipped with a recovery valve 16, which is located downstream of the venting pipe 14 and close to the low-pressure clean gas pipeline network 21. When the purified gas meets the recovery conditions, the recovery valve 16 is opened to allow the gas to enter the low-pressure clean gas pipeline network 21 for recovery. When the purified gas does not meet the recovery conditions, the recovery valve 16 is closed, and the on / off valve on the venting pipe 14 is opened to allow the gas to be released outward through the venting pipe 14 without entering the low-pressure clean gas pipeline network 21 for recovery.

[0045] In some embodiments, such as Figure 1 As shown, at least one ejector includes a pre-ejector 4 and a post-ejector 5. The pre-ejector 4 is located upstream of the second dust collector group, and the post-ejector 5 is located downstream of the connection between the collecting pipeline 3 and the second recovery pipeline 2, and upstream of the connection between the vent pipe 14 and the second recovery pipeline 2. By setting two ejectors, the smooth delivery of gas can be ensured, especially during the shutdown phase, allowing the gas from the furnace top riser 19 to enter the second recovery pipeline 2 more quickly, thus accelerating the recovery of the gas from the furnace top riser 19. The post-ejector 5 can be opened only during shutdown recovery to quickly introduce gas meeting the recovery conditions into the low-pressure clean gas pipeline network 21 for recycling.

[0046] In some embodiments, continue to combine Figure 1 At least one ejector also includes a recirculation ejector 17. At least one ejector is located on the dry dust removal box of the first recovery pipeline 1. The recirculation ejector 17 is used to quickly introduce the flue gas in the blast furnace 18 into the first recovery pipeline 1 at the initial stage of recirculation of the blast furnace 18, and then release it after dust removal.

[0047] Both the first valve group 6 and the second valve group 7 include at least a butterfly valve and a blind valve connected in series to ensure the normal operation of the venting and recovery system.

[0048] like Figure 1 As shown, the first dust collector group includes a first gravity dust collector 9 and multiple first baghouse dust collectors 10 connected in series. The first gravity dust collector 9 is located upstream of the multiple first baghouse dust collectors 10. During the shutdown of blast furnace 18, the multiple first baghouse dust collectors 10 are closed one by one, and during the restart of blast furnace 18, the multiple first baghouse dust collectors 10 are opened one by one. The first gravity dust collector 9 is a large gravity dust collector used for dust removal from the gas at the top of the blast furnace during the production process of blast furnace 18. The multiple first baghouse dust collectors 10 all adopt dry dust collection boxes used for dust removal from the gas at the top of the blast furnace during the production process of blast furnace 18.

[0049] The second dust collector group includes a second gravity dust collector 11 and a second bag filter 12. The second gravity dust collector 11 is located upstream of the second bag filter 12. The second gravity dust collector 11 is a small gravity dust collector used for dust removal from the blast furnace top charge hopper 22 during the blast furnace 18 production process. The second bag filter 12 is a pressure equalization dust collection box used for dust removal from the charge hopper 22 at the furnace top during the blast furnace 18 production process.

[0050] The operation process of the venting and recovery system according to an embodiment of this application is described below:

[0051] Shutdown Operation Process: In the early stage of the shutdown process, blast furnace 18 maintains the blast furnace 18 gas recovery treatment as it would during normal production, i.e., through natural recovery under top pressure. The blast furnace 18 gas enters the high-pressure clean gas pipeline 20 after being purged by the first gravity dust collector 9 and multiple first bag dust collectors 10. When the blast furnace top pressure drops to 0.03 MPa and the hot blast pressure drops to 0.1 MPa, the first valve group 6 and the second valve group 7 are opened, and multiple first bag dust collectors 10 are gradually closed, cutting off the first bag dust collectors 10 until only one bag dust collector 10 remains and is connected to the first recovery pipeline 1. The main shut-off valve on the high-pressure clean gas pipeline 20 is closed, and the pre-ejector 4 and the post-ejector 5 are opened for rapid recovery during shutdown. The gas purged by the first and second dust collector groups enters the low-pressure clean gas pipeline network 21. Blast furnace 18 continues to reduce blast and pressure until... The blast furnace 18 has a blast volume of 0, a hot blast pressure of 0.05 MPa, and a furnace top pressure of 0.02 MPa. If the gas analyzer 13 on the second recovery pipeline 2 and the original gas analyzer on the high-pressure clean gas pipeline 20 detect that the gas does not meet the recovery conditions, the on / off valve on the vent pipe 14 will open and the recovery valve 16 will be shut off. The gas will be released through the vent pipe 14 and will not enter the low-pressure clean gas pipeline 21 for recovery. At this time, the gas volume in the blast furnace top is very low. The first dust collector group and the first valve group 6 can be shut down, and only the second bag filter 12 can be used until the shutdown is completed.

[0052] Re-air operation process: When the gas in the blast furnace 18 is not suitable for recovery at the beginning of the re-air process, the second valve group 7 is opened, and the gas is purified by the second dust collector group and then released through the vent pipe at the top of the second bag dust collector; at the same time, the re-air ejector 17 on the first bag dust collector 10 on the first recovery pipeline 1 is opened, so that the purified gas is directly released through the re-air ejector 17. As the re-air process proceeds, based on the gas analyzer 13 and the gas analyzer on the first bag filter 10 (not shown in the figure), which detects that the coal gas is suitable for recovery, the recovery valve 16 is opened, the first valve group 6 is opened, the furnace top vent valve 23 and the re-air ejector 17 are closed, and the pre-ejector 4 and the post-ejector 5 are opened to start the re-air process. As the hot air pressure increases, all the first bag filters 10 are gradually opened, and the purified coal gas enters the low-pressure clean coal gas pipeline 21 until all the first bag filters 10 are put into use. When the re-air process is completed, the first valve group 6 and the second valve group 7 are closed, and the coal gas is normally recovered through the first dust collector group on the first recovery pipeline 1. The recovered coal gas enters the high-pressure clean coal gas pipeline 20 and, after a series of treatments, flows into the low-pressure clean coal gas pipeline 21.

[0053] The above description is intended to be illustrative and not restrictive. Those skilled in the art can make variations, modifications, substitutions, and alterations to the above embodiments within the scope of this disclosure. Moreover, the above examples (or one or more of them) can be used in combination with each other, and these embodiments can be combined with each other in various combinations or arrangements.

Claims

1. A blast furnace gas venting and recovery system, characterized in that, include: The first recovery pipeline is connected at one end to the first position on the top of the blast furnace and at the other end to the high-pressure clean gas pipeline. The second recovery pipeline has one end connected to the second position on the top of the blast furnace and the other end connected to the low-pressure clean gas pipeline network. The second position is located below the first position. The first dust collector group is located on the first recovery pipeline and is used to remove dust from the blast furnace gas entering the first recovery pipeline. The second dust collector unit is located on the second recovery pipeline and is used to remove dust from the blast furnace gas entering the second recovery pipeline. A collection pipeline is provided, with one end connected to the first recovery pipeline and the other end connected to the second recovery pipeline. The connection point between the collection pipeline and the first recovery pipeline is located downstream of the first dust collector group, and the connection point between the collection pipeline and the second recovery pipeline is located downstream of the second dust collector group. A first valve group is provided on the collection pipeline. The first valve group is used to open when the blast furnace is in the process of shutdown and restart, so that the gas after dust removal by the first dust collector group can be collected into the low-pressure clean gas pipeline network. At least one ejector is provided on the first recovery pipeline and / or the second recovery pipeline for opening when the blast furnace is in the process of shutting down and restarting, so as to quickly introduce the gas in the blast furnace into the first recovery pipeline and / or the second recovery pipeline for recovery or venting after dust removal.

2. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 1, characterized in that, The second recovery pipeline is also equipped with a second valve group, which is located upstream of the second dust collector group. The second valve group is used to open when the blast furnace is in the process of shutdown and restart, so that the gas in the blast furnace enters the second recovery pipeline, and after being dusted by the second dust collector group and meeting the recovery conditions, it enters the low-pressure clean gas pipeline network.

3. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 1, characterized in that, The blast furnace gas shutdown and restart venting and recovery system also includes a controller and a gas analyzer and a venting pipe installed on the second recovery pipeline. The gas analyzer and the venting pipe are both located downstream of the second dust collector group, and the gas analyzer is located upstream of the venting pipe. The gas analyzer is located upstream of the connection between the collecting pipeline and the second recovery pipeline, and the venting pipe is located upstream of the connection between the collecting pipeline and the second recovery pipeline. The venting pipe is equipped with an on / off valve. The gas analyzer is used to detect the oxygen content in the dust-removed coal gas, and generates a first signal when the oxygen content is lower than a preset value, and generates a second signal when the oxygen content is higher than the preset value. The controller is electrically connected to the gas analyzer and the on / off valve respectively. When the controller receives the first signal, it controls the first valve group to close and controls the on / off valve to open so that the dust-removed coal gas can be released through the vent pipe. When the controller receives the second signal, it controls the first valve group to open and controls the on / off valve to close so that the dust-removed coal gas can be recycled into the low-pressure clean coal gas pipeline network.

4. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 3, characterized in that, At least one of the ejectors includes a pre-ejector and a post-ejector, the pre-ejector being located upstream of the second dust collector assembly, and the post-ejector being located downstream of the junction of the collecting pipeline and the second recovery pipeline, and upstream of the junction of the venting pipe and the second recovery pipeline.

5. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 3, characterized in that, The second recovery pipeline is also equipped with a check valve, which is located downstream of the gas analyzer and upstream of the connection between the collection pipeline and the second recovery pipeline.

6. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 3, characterized in that, The second recovery pipeline is also equipped with a recovery valve, which is located downstream of the vent pipe. The recovery valve is used to control the entry of the dust-removed coal gas into the low-pressure clean coal gas pipeline network.

7. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 1, characterized in that, The first dust collector group includes a first gravity dust collector and a plurality of first bag dust collectors connected in series. The first gravity dust collector is located upstream of the plurality of first bag dust collectors. During the blast furnace shutdown process, the plurality of first bag dust collectors are closed one by one, and during the blast furnace restart process, the plurality of first bag dust collectors are opened one by one. The first gravity dust collector is a gravity dust collector used in the blast furnace production process to remove dust from the blast furnace top gas; the multiple first bag dust collectors are all dry dust collection boxes used in the blast furnace production process to remove dust from the blast furnace top gas.

8. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 7, characterized in that, At least one of the ejectors also includes a recirculation ejector, which is installed on the dry dust collection box on the first recovery pipeline. The recirculation ejector is used to quickly introduce the flue gas in the blast furnace into the first recovery pipeline for dust removal and then release it when the blast furnace is in the initial stage of recirculation.

9. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 1, characterized in that, The second dust collector group includes a second gravity dust collector and a second bag filter. The second gravity dust collector is located upstream of the second bag filter. The second gravity dust collector is a gravity dust collector used to remove dust from the material hopper at the top of the blast furnace during the blast furnace production process. The second bag filter is a pressure equalization dust collector box used to remove dust from the material hopper at the top of the blast furnace during the blast furnace production process.

10. The blast furnace gas shutdown and restart venting recovery and treatment system according to claim 2, characterized in that, Both the first valve group and the second valve group include at least a butterfly valve and a blind valve connected in series.

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