A flue gas treatment device

Abstract

This invention provides a flue gas treatment device that improves adsorbent usage and increases adsorption efficiency through structural improvements. The device includes at least one separation chamber and a gas collection chamber. The separation chamber contains several collection cylinders, each with a first gas channel. A second gas channel is defined by the collection cylinders and the separation chamber. The first gas channel has a first inlet, a first outlet, and a second outlet. The flue gas to be separated enters the first gas channel through the first inlet, the first outlet communicates with the corresponding gas collection chamber, and the second outlet communicates with the second gas channel. The second gas channel of at least one separation chamber is filled with adsorbent. In this invention, pollutants in the separated gas are removed by contacting the separated gas with the adsorbent, reducing the amount of gas in contact with the adsorbent per unit of flue gas to be separated, thus improving adsorption efficiency and reducing the amount of adsorbent used per unit of flue gas to be separated.

Description

Technical Field

[0001] This invention relates to the field of flue gas treatment technology, and more specifically, to a flue gas treatment device. Background Technology

[0002] For the treatment of industrial waste gas pollutants such as dust and nitrogen oxides, the denitrification and dust removal processes are implemented separately, which requires a large area, large investment, high resistance, and high operating costs. In order to avoid this drawback, some devices integrate the denitrification and dust removal processes, so that the flue gas first passes through the dust collection section to purify the dust-laden raw flue gas, and then the dust-free flue gas enters the denitrification section for denitrification. However, in traditional denitrification methods, in order to remove pollutants, the amount of adsorbent used is large, and the adsorption capacity of the flue gas per unit time is low. Summary of the Invention

[0003] The purpose of this invention is to provide a flue gas treatment device that reduces the amount of adsorbent used and improves adsorption efficiency by improving the structure of the flue gas treatment device.

[0004] To achieve the above objectives, the present invention provides a flue gas treatment device, comprising at least one separation chamber and a gas collection chamber. The separation chamber contains a plurality of collection tubes, each of which has a first air passage. A second air passage is defined between the collection tube and the separation chamber. The first air passage has a first inlet, a first outlet, and a second outlet. The flue gas to be separated enters the first air passage through the first inlet. The first outlet is connected to the corresponding gas collection chamber, and the second outlet is connected to the second air passage. At least one of the separation chambers has its second air passage filled with an adsorbent.

[0005] In the technical solution of this application, the adsorbent is placed in the second gas channel, which can remove one or more gases from the flue gas to be separated to form a separated gas before the adsorption process. The pollutants in the separated gas are removed by contacting the adsorbent. In this way, the amount of gas in contact with the adsorbent per unit of flue gas to be separated is reduced, the adsorption efficiency is improved, and the amount of adsorbent used for the adsorption process of each unit of flue gas to be separated is reduced.

[0006] Optionally, the separation chamber for performing a single separation process on the flue gas is defined as a separation chamber, and the collection tube in the separation chamber is used to collect nitrogen. Since nitrogen accounts for more than 70% of the original flue gas by volume, separating nitrogen from the flue gas to be separated by the separation chamber can quickly reduce the amount of remaining flue gas.

[0007] Optionally, the flue gas treatment device further includes a dust removal chamber, and the first inlet of the separation chamber is connected to the tail flue through the dust removal chamber. In this way, the raw flue gas discharged from the tail of the boiler will first enter the dust removal chamber for dust removal, thereby ensuring that all chambers downstream of the dust removal chamber are in a dust-free operating condition.

[0008] Optionally, the dust removal chamber includes a fire extinguishing section and a dust collection section. In the direction of flue gas inlet, the fire extinguishing section is located upstream of the dust collection section. The fire extinguishing section is equipped with several fire extinguishing nozzles, which are connected to the gas collection chamber. This allows the nitrogen collected in the gas collection chamber to be sprayed as a flame retardant to form a nitrogen air curtain, thereby extinguishing any sparks carried by the original flue gas and preventing the safety hazard caused by sparks re-igniting dust after entering the dust collection section.

[0009] Optionally, the dust removal chamber is equipped with a plurality of filter bags, each filter bag having a flue gas outlet connected to the first inlet of the separation chamber; it also includes pulse jet cleaning components, each corresponding to a flue gas outlet and connected to the gas collection chamber. This allows nitrogen from the gas collection chamber to be used as a pulse jet cleaning source to be injected into the dust collection section, not only cleaning the filter bags but also reducing the oxygen content in the dust removal chamber, further extinguishing sparks carried by the original flue gas and preventing dust reignition. Furthermore, excess nitrogen is collected along with the dust-free flue gas through the flue gas outlet into the collection cylinder of the separation chamber, thus preventing an increase in the amount of residual flue gas in contact with the adsorbent. This also allows for repeated utilization and collection of nitrogen, improving energy efficiency.

[0010] Optionally, the system also includes a pneumatic ash conveying device and an ash hopper. The ash hopper is used to collect dust from the dust removal chamber, and the pneumatic ash conveying device is used to transport the dust from the ash hopper to the ash silo. The pneumatic ash conveying device is connected to the gas collection chamber. This allows nitrogen to be used as the gas source for the pneumatic ash conveying device, which not only conveys ash but also acts as a flame retardant to prevent the dust from reigniting.

[0011] Optionally, it also includes a heat exchange chamber, located between the separation chamber and the dust removal chamber in the flue gas inlet direction; the flue gas undergoes heat exchange within the heat exchange chamber. This reduces the temperature of the dust-free flue gas, significantly decreasing the volumetric flow rate of the low-temperature dust-free flue gas. Consequently, it reduces the temperature and volumetric flow rate of the flue gas in subsequent chambers, thereby reducing the membrane area and adsorbent usage in the membrane separation tube bundle, and lowering investment and operating costs.

[0012] Optionally, the chamber connected to the first separation chamber is defined as the second separation chamber. The first inlet of the first air passage of the second separation chamber is connected to the exhaust port of the first separation chamber; the exhaust port of the second separation chamber is connected to a suction fan. In this way, the first separation chamber performs a first separation of the flue gas to be separated, and the first separated gas enters the first air passage of the second separation chamber for a second separation, which can further separate some of the gas in the first separated gas. By connecting the suction fan to the exhaust port of the second separation chamber, a negative pressure can be formed in the two connected separation chambers, improving the collection efficiency of the collection tube.

[0013] Optionally, the collection cylinder within the second separation chamber is used to capture carbon dioxide, and the gas collection chamber corresponding to and connected to the second separation chamber is defined as the second gas collection chamber, which is used to collect the captured carbon dioxide. In this way, the carbon content in the secondary separation gas can be reduced, thus reducing carbon emissions, while collecting the carbon dioxide facilitates subsequent utilization and avoids energy waste. Furthermore, the carbon dioxide content in flue gas is typically about 5% to 15%, and by capturing and collecting the carbon dioxide, the volume of the secondary separation gas can be further reduced.

[0014] Optionally, the system also includes a three-chamber gas collection system, which is connected to the exhaust port of the two-chamber separation system, and the suction fan is located between the three-chamber gas collection system and the exhaust port of the two-chamber separation system. By setting up the three-chamber gas collection system, the remaining flue gas after secondary capture can be collected centrally, which can replace the traditional method of exhaust through a chimney. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0016] Figure 1 This is a schematic diagram of the structure of the flue gas treatment device in an embodiment of the present invention;

[0017] Figure 2 yes Figure 1 A cross-sectional view of the separation chamber in the image;

[0018] Figure 3 It is a cross-sectional view of a separate chamber collection tube;

[0019] Figure 4 This is a cross-sectional view of the two-chambered collection tube;

[0020] Figure 5 This is a cross-sectional view of the fire extinguishing section.

[0021] Figure label:

[0022] 1-Dust removal chamber; 11-Fire extinguishing section; 12-Dust collection section; 101-Filter bag; 102-Ash hopper; 103-Pneumatic ash conveying device; 104-Ash conveying pipeline; 105-Soot blowing pipeline; 106-Pulse blowing pipe; 111-Fire extinguishing pipeline; 112-Fire extinguishing nozzle; 2-Heat exchange chamber; 201-Heat exchange tube; 202-Fin; 3-Suction fan; 301-Nitrogen film separation tube bundle; 302-First cylinder; 501-Carbon-containing film separation tube bundle; 502-Second cylinder; 40-Collection cylinder; 41-First air duct; 42-Second air duct; 5-Tail flue; 61-Desiccant; 62-Adsorbent; 7-Gas collection chamber; 71-Gas collection chamber one; 72-Gas collection chamber two; 73-Gas collection chamber three; 8-Separation chamber; 81-Separation chamber one; 82-Separation chamber two. Detailed Implementation

[0023] This invention provides a flue gas treatment device that reduces the amount of adsorbent used and improves adsorption efficiency by improving the structure of the flue gas treatment device.

[0024] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0026] Please refer to Figures 1 to 5 , Figure 1 This is a schematic diagram of the structure of the flue gas treatment device in an embodiment of the present invention; Figure 2 yes Figure 1 A cross-sectional view of the separation chamber 8 in the middle; Figure 3 It is a cross-sectional view of a separate chamber collection tube; Figure 4 This is a cross-sectional view of the two-chambered collection tube; Figure 5 This is a cross-sectional view of the fire extinguishing section.

[0027] As shown in the figure, the present invention includes a flue gas treatment device, which includes a suction fan 3, at least one separation chamber 8 and at least one gas collection chamber 7. The gas collection chamber 7 is connected to the separation chamber 8. The separation chamber 8 is provided with a plurality of collection tubes 40, each collection tube 40 including a plurality of membrane separation tube bundles. The set gas is collected and separated by the membrane separation tube bundles. The membrane separation tube bundles are membranes of polymers (such as polyimide or polysulfone) bent into a tubular structure to achieve gas separation. Specifically, when a mixture of multiple gases passes through the membrane separation tube bundles, due to the difference in the solubility and diffusion coefficients of each gas component in the polymer, some gas remains inside the membrane separation tube bundles, and some gas mixtures pass through the membrane to the outside of the membrane separation tube bundles.

[0028] The collection tube 40 has a first air passage 41, which is defined within the membrane separation tube bundle. The first air passage 41 is used to pass through the flue gas to be separated. That is, the first air passage 41 has a first inlet, a first outlet, and a second outlet. The second outlet is directly or indirectly connected to the suction fan 3 to create a negative pressure outside the first air passage 41. The first inlet is directly or indirectly connected to the tail flue 5, and the first outlet is connected to the gas collection chamber 7. The first inlet and the first outlet are located at opposite ends of the axial direction of the membrane separation tube bundle, and the second outlet is the membrane pore of the membrane itself. In this way, a low-pressure side is formed outside the membrane separation tube bundle by the suction fan 3, and a high-pressure side is formed inside the membrane separation tube bundle. At the same time, the gas collection chamber 7 forms a low-pressure side compared to the inside of the membrane separation tube bundle. Under the action of the suction fan 3, the flue gas to be separated enters the first air passage 41 through the first inlet. Part of the flue gas is discharged from the inside of the membrane separation tube bundle through the second outlet under the action of the suction fan 3. This part of the flue gas serves as the separated gas, and the remaining part of the flue gas is the set gas to be captured. This gas enters the gas collection chamber 7 through the first outlet. In subsequent embodiments, nitrogen and carbon dioxide will be used as the set gases for illustration. Of course, those skilled in the art can select other set gases according to actual needs, and select the corresponding model and material of the membrane according to the gas, which will not be elaborated here.

[0029] The inner surface of the wall between the collecting cylinder 40 and the separation chamber 8 defines a second air passage 42. Under the action of the suction fan 3, the first air passage 41 forms a high-pressure side, and the second air passage 42 forms a low-pressure side. In a specific example, each collecting cylinder 40 also includes a cylinder body, in which a plurality of membrane separation tube bundles are disposed. Each membrane separation tube bundle extends along the axial direction of the cylinder body, and the first air passage 41 defined by each membrane separation tube bundle penetrates the two end faces of the cylinder body along its extension direction to form a plurality of first inlets and a plurality of first outlets. A portion of the wall of the separation chamber 8 serves as the cylinder body. The end faces, that is, the two ends of each cylinder are welded to the corresponding side walls of the separation chamber 8. Thus, a space within the cylinder is formed between part of the cavity wall (cylinder end face), the inner wall of the cylinder, and the outer wall of the membrane separation tube bundle. Openings are provided on the side walls of each cylinder. The outer wall of the cylinder and the other part of the cavity wall of the separation chamber 8 form a second air passage 42. The second outlet of the membrane separation tube bundle is connected to the space within the cylinder. The space within the cylinder is connected to the second air passage 42 through the openings in the cylinder. The second air passage 42 penetrates the cavity wall of the separation chamber 8 to form an exhaust port, through which the separated gas is discharged from the separation chamber 8. In this embodiment, at least one second air passage 42 of the separation chamber 8 is filled with an adsorbent 62 to perform desulfurization, denitrification, or other processes to remove pollutants from the separated gas. Specifically, the adsorbent 62 includes selective adsorbents such as desiccant 61, activated carbon, molecular sieves, and iron oxide, which respectively adsorb pollutants such as water vapor, sulfur oxides, nitrogen oxides, and carbon monoxide in the separated gas.

[0030] In the technical solution of this application, by placing the adsorbent 62 in the second gas channel 42, one or more gases in the flue gas to be separated can be removed to form a separated gas before the adsorption process. The pollutants in the separated gas are removed by contacting the separated gas with the adsorbent 62. In this way, the amount of gas in contact with the adsorbent 62 per unit of flue gas to be separated is reduced, the adsorption efficiency is improved, and the amount of adsorbent 62 used for the adsorption process of each unit of flue gas to be separated is reduced.

[0031] The technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0032] In a specific embodiment, the separation chamber 8 that performs a first separation process on the flue gas is defined as separation chamber 81. The first separation process refers to the separation chamber 8 that performs the first separation of the flue gas in the separation process. The flue gas entering the separation chamber 81 has not undergone a separation process before. It can be the original flue gas from the tail flue 5, or it can be dust-free flue gas that has undergone a dust removal process and / or low-temperature (dust-free) flue gas that has undergone a cooling process. The gas collection chamber 7 that is connected to the separation chamber 81 is called gas collection chamber 71. The membrane separation tube bundle in the separation chamber 81 is used to capture nitrogen gas, and the gas collection chamber 71 is used to collect the captured nitrogen gas. The second gas channel 42 of the separation chamber 81 is filled with adsorbent 62.

[0033] Specifically, the separation chamber 81 is equipped with a nitrogen collection cylinder 40. Each collection cylinder 40 includes several first cylinders 302, and each first cylinder 302 contains several membrane separation tube bundles (hereinafter referred to as "nitrogen membrane separation tube bundles 301") for separating nitrogen. The first gas collecting chamber 7 is located at one end of the nitrogen membrane separation tube bundle 301 along its axial direction and is connected to the first outlet of the nitrogen membrane separation tube bundle 301. At this time, the suction fan 3 can be indirectly or directly connected to the second air passage 42 of the separation chamber 81. Since the volume fraction of nitrogen accounts for more than 70% of the original flue gas, separating nitrogen from the flue gas to be separated by the separation chamber 81 can quickly reduce the amount of gas to be separated. Of course, in addition to capturing nitrogen, the separation chamber 81 can also be used to capture other gases, as long as the amount of gas in contact with the adsorbent 62 is reduced.

[0034] Optionally, such as Figure 2As shown, the flue gas treatment device is also filled with desiccant 61. The first cylinder 302 has a double-layer structure, with an inner cylinder and an outer cylinder. The nitrogen membrane separation tube bundle 301 is located in the inner cylinder. The outer wall of the outer cylinder and the inner surface of the cavity wall of the separation chamber 81 form a second gas channel 42. The space between the inner cylinder and the outer cylinder is filled with desiccant 61. The inner cylinder has several holes, and the outer cylinder has several holes. The primary separation gas after separation by the nitrogen membrane separation tube bundle 301 passes through the holes in the inner and outer cylinders and passes through the desiccant 61 to preferentially remove moisture from the primary separation gas, so as to avoid the moisture affecting the activity of other adsorbents 62 and reduce the amount of other adsorbents 62 used.

[0035] In the above embodiment, the flue gas treatment device further includes a dust removal chamber 1, and the first inlet of the separation chamber 81 is connected to the tail flue 5 through the dust removal chamber 1. In this way, the raw flue gas discharged from the boiler tail end will first enter the dust removal chamber 1 for dust removal, thereby ensuring that each chamber downstream of the dust removal chamber 1 operates in a dust-free condition. In the example shown in the figure, vertically, the dust removal chamber 1 is located below the separation chamber 81, and the nitrogen film separation tube bundle 301 within the separation chamber 81 extends vertically, so the first inlet at the bottom is connected to the dust removal chamber 1 located below; the first gas collecting chamber 7 is vertically located on the side of the separation chamber 81 away from the dust removal chamber 1, that is, above the dust removal chamber 1, and the first outlet at the axial top of the nitrogen film separation tube bundle 301 is connected to the first gas collecting chamber 7. This arrangement utilizes vertical space to arrange three chambers, improving the utilization of vertical space in the flue gas treatment device, and also facilitating the falling of dust in the flue gas under the influence of gravity.

[0036] In one specific embodiment, an electrostatic precipitator or a filter bag 101 dust removal device is installed in the dust removal chamber 1. The following is a specific description using the filter bag 101 as an example. The filter bag 101 has a flue gas outlet, which is connected to the first inlet of the separation chamber 81. The flue gas outlet is located at the top of the dust removal chamber 1, that is, the part of the dust removal chamber 1 facing the separation chamber 81. The dust removal chamber 1 also has a flue gas inlet, which is connected to the tail flue 5 of the boiler. The original flue gas enters the dust removal chamber 1 through the flue gas inlet, passes through the filter bag 101, and is discharged from the flue gas outlet.

[0037] The flue gas treatment device also includes pulse jet components, each corresponding to a flue gas outlet, and connected to the gas collection chamber 71. Specifically, the flue gas treatment device is equipped with a blowpipe 106, which is connected to a pulse jet cleaning element, such as a nozzle. Since this is existing technology, it will not be described further. The blowpipe 106 is connected to the gas collection chamber 71 via a soot blowing pipe 105. This allows nitrogen from the gas collection chamber 71 to be used as a pulse jet cleaning gas source and blown into the dust collection section 12. This not only cleans the filter bag 101 but also reduces the oxygen content in the dust collection chamber 1, extinguishing sparks carried by the original flue gas and preventing dust reignition. Furthermore, excess nitrogen is collected along with the dust-free flue gas through the flue gas outlet into the collection cylinder 40 of the separation chamber 81. This prevents an increase in the amount of flue gas in contact with the adsorbent 62 and allows for repeated utilization and collection of nitrogen, improving energy efficiency.

[0038] In an optional embodiment, the dust removal chamber 1 specifically includes a fire extinguishing section 11 and a dust collection section 12. The aforementioned filter bag 101 is disposed in the dust collection section 12. In the direction of flue gas inlet, the fire extinguishing section 11 is located upstream of the dust collection section 12, that is, compared with the dust collection section 12, the fire extinguishing section 11 is closer to the tail flue 5. The fire extinguishing section 11 is provided with a plurality of fire extinguishing nozzles 112, and the fire extinguishing nozzles 112 are connected to the gas collection chamber 71. In one specific implementation, the fire extinguishing section 11 is connected to the tail flue 5. A fire extinguishing pipe 111 is installed around the outer wall of the fire extinguishing section 11, and the fire extinguishing pipe 111 is connected to a gas collection chamber 71. Nitrogen gas flows through the fire extinguishing pipe 111. The fire extinguishing pipe 111 also includes several interfaces, with fire extinguishing nozzles 112 corresponding to each interface. Several through holes are also provided on the pipe wall of the fire extinguishing section 11, and the fire extinguishing nozzles 112 extend into the fire extinguishing section 11 through the corresponding through holes to spray nitrogen gas into the fire extinguishing section 11. Figure 5 In the example shown, the cross-section of the extinguishing section 11 is quadrilateral, with four extinguishing nozzles 112 evenly distributed along each side of the quadrilateral, thereby forming a nitrogen air curtain. The cross-sectional shape of the extinguishing section 11 and the number of extinguishing nozzles 112 are not specifically limited here; those skilled in the art can choose accordingly. This allows the nitrogen collected in the gas collecting chamber 71 to be sprayed as a flame retardant to form a nitrogen air curtain, thereby extinguishing sparks carried by the original flue gas and preventing the safety hazard caused by sparks re-igniting dust after entering the dust collecting section 12. The extinguishing nozzles 112 can be high-pressure curtain nozzles, where the nitrogen sprayed by a single nozzle 112 has a stronger impact force and a larger coverage area, making it easier to extinguish sparks in the flue gas.

[0039] In another optional embodiment, a pneumatic ash conveying device 103 and an ash hopper 102 are also included. The ash hopper 102 is located vertically below the dust collection chamber 1 and is used to collect dust within the dust collection chamber 1. The pneumatic ash conveying device 103 is disposed below the ash hopper 102 to transport the dust collected in the ash hopper 102 to the target ash silo. The pneumatic ash conveying device 103 is connected to the gas collection chamber 71 via an ash conveying pipeline 104. This allows nitrogen to be used as the gas source for the pneumatic ash conveying device 103, which not only serves the function of conveying ash but also acts as a flame retardant to prevent the dust from reigniting.

[0040] In the above embodiments, the flue gas treatment device further includes a heat exchange chamber 2, which is located between the separation chamber 81 and the dust removal chamber 1 in the flue gas inlet direction. The flue gas treatment device includes a shell, and each chamber is located inside the shell. That is, the heat exchange chamber 2 is located inside the shell. The lower surface of the bottom cavity wall of the separation chamber 81 and the upper surface of the top cavity wall of the dust removal chamber 1, as well as the inner wall of the shell, define the heat exchange chamber 2. The heat exchange chamber 2 is provided with heat exchange tubes 201 and fins 202. The heat exchange tubes 201 are used to circulate the medium, and the fins 201... 2. This plays a role in improving heat exchange efficiency. After the dust removal of the dust collection section 12, the dust-free flue gas enters the heat exchange chamber 2. The low-temperature medium in the heat exchange tube 201 absorbs the heat of the flue gas and its temperature rises. After the dust-free flue gas is cooled down by the heat exchange chamber 2, the volumetric flow rate of the dust-free flue gas entering the separation chamber 81 is greatly reduced. By exchanging heat in the heat exchange chamber 2 to reduce the temperature of the dust-free flue gas, the volumetric flow rate of the dust-free flue gas is significantly reduced. This can reduce the membrane area of ​​the membrane separation tube bundle and the amount of adsorbent 62, thereby reducing investment and operating costs.

[0041] In other embodiments of this application, the chamber connected to the first separation chamber 81 is defined as the second separation chamber 82, which is used to perform a second separation process on the flue gas. The first inlet of the first air passage 41 of the second separation chamber 82 is connected to the exhaust port of the first separation chamber 81; the exhaust port of the second separation chamber 82 is connected to a suction fan 3. The primary separation gas after adsorption (the gas separated after primary separation) includes a mixture of oxygen and carbon dioxide, which enters the second separation chamber 82. In a specific example, the second separation chamber 82 is provided with a plurality of carbon-containing gas film separation tube bundles 501 for separating carbon dioxide. The plurality of carbon-containing gas film separation tube bundles 501 are arranged in groups in a plurality of second cylinders 502. The connection method between the second cylinders 502 and the plurality of carbon-containing gas film separation tube bundles 501 and the cavity wall of the second separation chamber 82 is the same as that of the first separation chamber 81. The difference is that, in the example shown in the figure, the nitrogen gas film separation tube bundle 3 in the first separation chamber 81 is... The separation chamber 81 is arranged vertically, while several carbon-containing gas film separation tube bundles 501 in the separation chamber 82 are arranged horizontally. In this way, the separation chamber 82 can be installed on the side wall of the separation chamber 81. This arrangement provides sufficient space for the separation chamber 82. At the same time, a suction fan 3 can be used to create negative pressure in the two separation chambers 8, thereby improving the integration of the flue gas treatment device and simplifying the structure of the flue gas treatment device. That is, in this embodiment, by connecting the suction fan 3 to the exhaust port of the separation chamber 82, negative pressure can be created in the two connected separation chambers 8, thereby improving the collection efficiency of the collection tube 40.

[0042] Optionally, the gas collecting chamber 7 connected to the secondary separation chamber 82 is defined as the secondary gas collecting chamber 72, which is used to collect the captured carbon dioxide. In this way, the carbon content in the secondary separation gas can be reduced, thus reducing carbon emissions. At the same time, the carbon dioxide is collected for subsequent use, avoiding energy waste. In addition, the carbon dioxide content in flue gas is usually about 5% to 15%. By capturing and collecting carbon dioxide, the amount of secondary separation gas can be further reduced.

[0043] In another alternative approach, the secondary separated gas, after separation by several carbon-containing gas film separators 501, is an oxygen-containing mixture. To collect the oxygen, the flue gas treatment device also includes a three-chamber gas collection unit 73, which is connected to the exhaust port of the second separation chamber 82. A suction fan 3 is located between the exhaust ports of the three-chamber gas collection unit 73 and the second separation chamber 82. By setting up the three-chamber gas collection unit 73, the remaining flue gas after secondary capture is collected centrally, replacing the traditional method of exhaust through a chimney. Of course, the secondary separated gas can also be exhausted through a chimney; even if it is exhausted, the carbon content of the secondary separated gas can be significantly reduced.

[0044] The flue gas treatment process of the embodiment shown in the figure is described below:

[0045] Step 1: Fire Extinguishing Procedure

[0046] The high-temperature dust-laden flue gas (original flue gas) first passes through the extinguishing section 11, where nitrogen is continuously sprayed in by multiple extinguishing nozzles 112 to form a nitrogen air curtain to extinguish the sparks carried into the dust removal chamber 1 by the high-temperature dust-laden flue gas. The gas source in the extinguishing pipeline 111 is the nitrogen collected in the gas collection chamber 71.

[0047] Step 2: Dust Removal Process

[0048] The flue gas enters the dust collection section 12, where it undergoes a dust removal process under the action of the filter bags 101. Most of the dust falls directly into the ash hopper 102, while the remaining dust is captured by the filter bags 101. To blow the dust off the filter bags 101, pulse jet cleaning devices are periodically activated to blow the dust adhering to the surface of the filter bags 101 into the ash hopper 102. The dust in the ash hopper 102 is discharged by the pneumatic ash conveying device 103, whose air source is nitrogen supplied by the ash conveying pipeline 104.

[0049] Step 3: Cooling process

[0050] After dust removal in the dust collection section 12, the dust-free flue gas enters the heat exchange chamber 2, which includes heat exchange tubes 201 and fins 202. The low-temperature medium entering the heat exchange tubes 201 absorbs heat from the flue gas and its temperature rises. The low-temperature medium can be a gas. After exchanging heat with the high-temperature dust-free flue gas, the low-temperature medium becomes a high-temperature medium. The high-temperature medium can be introduced into the boiler to aid combustion and preheat the air, thus saving energy and reducing consumption. The flow direction of the low-temperature medium can be determined according to the actual situation. The fins 202 play a role in improving heat exchange efficiency, and their shape can be square, round, spiral, sawtooth, etc. After cooling down in the heat exchange chamber 2, the volumetric flow rate of the flue gas is significantly reduced.

[0051] Step 4: First Separation

[0052] After passing through the heat exchange chamber 2, the high-temperature dust-free flue gas is transformed into low-temperature dust-free flue gas. The low-temperature dust-free flue gas enters the separation chamber 81. Specifically, the low-temperature dust-free flue gas enters the nitrogen membrane separation tube bundle 301 through the first inlet. Since nitrogen cannot pass through the nitrogen membrane separation tube bundle 301, under the pressure difference of the suction fan 3, oxygen, carbon dioxide, water vapor, sulfur oxides, nitrogen oxides and other primary separated gases enter the second gas channel 42 filled with adsorbent 62 through the side (second outlet) of the nitrogen membrane separation tube bundle 301. The flue gas treatment device can also be filled with desiccant 61, activated carbon, molecular sieve, iron oxide and other selective adsorbents 62, which can selectively adsorb and remove pollutants such as water vapor, sulfur oxides, nitrogen oxides, carbon monoxide and other pollutants in the separated gas, while allowing carbon dioxide to pass through. The mixing ratio of each adsorbent 62 can be adjusted according to different flue gas conditions, different pollutant generation ratios and other conditions. Nitrogen enters the gas collection chamber 71 from the first outlet at the top of the nitrogen membrane separation tube bundle 301.

[0053] Step 5: Secondary Separation

[0054] After being adsorbed by the second air passage 42 in the first separation chamber 81, the primary separation gas enters the second separation chamber 82. Specifically, it enters through the first inlet of the carbon-containing gas film separation tube bundle 501. The interior of the carbon-containing gas film separation tube bundle 501 contains carbon dioxide, and the exterior forms a secondary separation gas. Under the pressure difference of the suction fan 3, the secondary separation gas enters the third gas collection chamber 73 through the side (second outlet) of the carbon-containing gas film separation tube bundle 501. Since the carbon dioxide cannot pass through the carbon-containing gas film separation tube bundle 501, it enters the second gas collection chamber 72 from the first outlet of the carbon-containing gas film separation tube bundle 501.

[0055] Compared with the prior art, the flue gas treatment device according to the present invention can achieve the following beneficial effects:

[0056] First, this patent prioritizes the dust removal process for the original flue gas, ensuring that all subsequent processes are in a dust-free environment, which helps improve the efficiency and lifespan of each chamber.

[0057] Secondly, the dust-free flue gas is cooled down. The flow rate of the low-temperature dust-free flue gas entering the separation chamber 8 is smaller, which can reduce the membrane area of ​​the membrane separation tube bundle and the amount of adsorbent 62.

[0058] Third, the nitrogen separated from the first chamber 81 can be utilized inside the flue gas treatment device. On the one hand, it is used as the gas source for the fire extinguishing nozzle 112 of the fire extinguishing section 11. The fire extinguishing nozzle 112 continuously sprays nitrogen to form an air curtain, which can extinguish the sparks carried into the device by the flue gas. On the other hand, it serves as the blowing gas source for the pulse jet and the ash conveying gas source for the pneumatic ash conveying device 103, playing the role of blowing the filter bag 101 to clean the dust and pneumatically conveying the dust. At the same time, it can also reduce the oxygen content in the dust removal chamber 1 and prevent dust from reigniting.

[0059] Fourth, since nitrogen accounts for more than 70% of the flue gas volume, the amount of primary separation gas entering the second gas duct 42 is less than 30% of the flue gas volume, which significantly reduces the amount of adsorbent 62 used and improves the adsorption efficiency.

[0060] Fifth, the two-chamber separation unit 82 separates oxygen and carbon dioxide, enabling the collection and utilization of oxygen and reducing carbon emissions.

[0061] Sixth, the nitrogen film separation tube bundle 301 in the first separation chamber 81 is arranged vertically, and the carbon-containing film separation tube bundle 501 in the second separation chamber 82 is arranged horizontally. A single suction fan 3 can provide a pressure difference for the two-stage flue gas separation chambers 8, without the need to compress the flue gas.

[0062] Seventh, separating and utilizing the original flue gas can replace the method of external discharge through chimneys, which saves energy, reduces emissions, and reduces investment.

[0063] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A flue gas treatment device, characterized in that, It includes a suction fan (3), at least one separation chamber (8) and a gas collection chamber (7). The separation chamber (8) is provided with a plurality of collection tubes (40). The collection tubes (40) include a plurality of membrane separation tube bundles. The membrane separation tube bundles define a first air passage (41). The first air passage (41) has a first inlet, a first outlet and a second outlet. The first inlet and the first outlet are located at the two ends of the axial direction of the membrane separation tube bundle. The first inlet is connected to the tail flue (5). The flue gas to be separated enters the first air passage through the first inlet. The first outlet is connected to the corresponding gas collection chamber (7). The second outlet is the membrane pore of the membrane body of the membrane separation tube bundle; the trapping tube (40) and the separation chamber (8) enclose and define a second air passage (42), and the second outlet is connected to the second air passage (42); the second outlet is directly or indirectly connected to the suction fan (3) to form a negative pressure outside the first air passage (41); at least one of the second air passages (42) of the separation chamber (8) is filled with an adsorbent (62).

2. The flue gas treatment device according to claim 1, characterized in that, The separation chamber (8) for performing a separation process on flue gas is defined as separation chamber (81), and the collection tube (40) of separation chamber (81) is used to collect nitrogen.

3. The flue gas treatment device according to claim 2, characterized in that, It also includes a dust removal chamber (1), and the first inlet of the separation chamber (81) is connected to the tail flue (5) of the boiler through the dust removal chamber (1).

4. The flue gas treatment device according to claim 3, characterized in that, The gas collection chamber (7) corresponding to and connected to the separation chamber (81) is defined as the gas collection chamber (71), which is used to collect nitrogen gas; the dust removal chamber (1) has a fire extinguishing section (11) and a dust collection section (12). Compared with the dust collection section (12), the fire extinguishing section (11) is closer to the tail flue (5); the fire extinguishing section (11) is provided with a number of fire extinguishing nozzles (112), which are connected to the gas collection chamber (71).

5. The flue gas treatment device according to claim 3, characterized in that, The gas collection chamber (7) corresponding to and connected to the separation chamber (81) is defined as the gas collection chamber (71), which is used to collect nitrogen. A plurality of filter bags (101) are provided in the dust removal chamber (1). The filter bags (101) have flue gas outlets, which are connected to the first inlet of the separation chamber (81). The flue gas treatment device also includes pulse jets, which correspond one-to-one with the flue gas outlets and are connected to the gas collection chamber (71).

6. The flue gas treatment device according to claim 3, characterized in that, The gas collection chamber (7) corresponding to and connected to the separation chamber (81) is defined as the gas collection chamber (71), which is used to collect nitrogen. The flue gas treatment device also includes a pneumatic ash conveying device (103) and an ash hopper (102). The ash hopper (102) is used to contain dust, and the pneumatic ash conveying device (103) is used to convey the dust in the ash hopper (102) to the ash silo. The pneumatic ash conveying device (103) is connected to the gas collection chamber (71).

7. The flue gas treatment device according to claim 3, characterized in that, It also includes a heat exchange chamber (2) for cooling the flue gas; the heat exchange chamber (2) is located between the separation chamber (81) and the dust removal chamber (1).

8. The flue gas treatment apparatus according to any one of claims 2-7, characterized in that, The second air passage (42) of each of the separation chambers (8) penetrates the cavity wall of the corresponding separation chamber (8) to form an exhaust port; the separation chamber (8) for which the flue gas is separated in a secondary separation process is defined as the second separation chamber (82), the first inlet of the first air passage (41) of the second separation chamber (82) is connected to the exhaust port of the first separation chamber (81), and the exhaust port of the second separation chamber (82) is connected to a suction fan (3).

9. The flue gas treatment device according to claim 8, characterized in that, The collection tube (40) of the separation chamber (82) is used to collect carbon dioxide. The gas collection chamber (7) that is connected to the separation chamber (82) is defined as the gas collection chamber (72), which is used to collect carbon dioxide.

10. The flue gas treatment apparatus according to claim 8, characterized in that, It also includes a three-chamber air collection chamber (73), which is connected to the exhaust port of the two-chamber separation chamber (82), and the suction fan (3) is located between the three-chamber air collection chamber (73) and the two-chamber separation chamber (82).

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