Flue gas collecting device and system for aluminum electrolysis cell

Abstract

The invention discloses a flue gas collecting device and system for an aluminum electrolysis cell. The flue gas collecting device comprises at least one high-temperature flue gas collecting mechanism communicating with the aluminum electrolysis cell and a smoke exhaust pipe communicating with the flue gas collecting mechanism. The high-temperature flue gas collecting mechanism comprises a flue gas collecting cover and a collecting cover branch pipe, the flue gas collecting cover is provided with a collecting cover first end and a collecting cover second end which are oppositely arranged, and the inner diameter of the flue gas collecting cover is gradually increased from the collecting cover first end to the collecting cover second end; the smoke collecting cover is arranged in the electrolytic bath, and the first end of the collecting cover is close to the fire holes in the electrolytic bath and is spaced from the fire holes in the electrolytic bath; the collecting cover branch pipe is provided with a branch pipe first end and a branch pipe second end which are oppositely arranged, the branch pipe first end penetrates through the baffle of the aluminum electrolysis cell to be communicated with the collecting cover second end, and the branch pipe second end is communicated with the smoke exhaust pipe. On the premise that the anode gas collection rate is guaranteed, the suction air volume and the energy consumption of a purification system such as a fan are remarkably reduced, and sufficient conditions are provided for follow-up flue gas waste heat utilization.

Description

Technical Field

[0001] This application belongs to the field of aluminum electrolysis flue gas treatment technology, specifically relating to a flue gas collection device and system for aluminum electrolysis cells. Background Technology

[0002] Under high temperature conditions of 930-950℃, the molten salt electrolyte in the aluminum electrolysis cell undergoes a complex physicochemical reaction between alumina and the prebaked anode, generating high-temperature anode gas rich in fluorides (such as HF), carbon dioxide, carbon monoxide and sulfur dioxide. These gases mainly escape from the shell-breaking and feeding point, commonly known as the "fire eye".

[0003] The current industry-standard gas collection method using on-site gas hoods has the following drawbacks: First, it has high energy consumption. To prevent flue gas from overflowing from the tank cover, the gas collection system must operate under a large negative pressure, which increases the load on the purification system. Second, the pollutant concentration is low and the carbon dioxide capture is not economically viable. Because the purification system draws in a large amount of cold air to dilute the anode gas, it not only reduces the pollutant concentration and affects the adsorption efficiency of hydrogen fluoride by alumina in the subsequent dry purification system, but also significantly reduces the carbon dioxide concentration in the flue gas, increasing the cost and difficulty of capture and storage. Summary of the Invention

[0004] To address the current technical challenges of high cost and difficulty in collecting flue gas from aluminum electrolysis cells, this application provides a flue gas collection device for aluminum electrolysis cells.

[0005] In a first aspect of this application, a flue gas collection device for an aluminum electrolysis cell is provided, comprising at least one high-temperature flue gas collection mechanism connected to the aluminum electrolysis cell and an exhaust pipe connected to the flue gas collection mechanism. The high-temperature flue gas collection mechanism includes: A flue gas collection hood has a first end and a second end of the collection hood arranged opposite to each other, and the inner diameter of the flue gas collection hood gradually increases from the first end to the second end of the collection hood; the flue gas collection hood is disposed in the electrolytic cell, and the first end of the collection hood is close to the flame hole in the electrolytic cell and is spaced apart from the flame hole in the electrolytic cell; The collection hood branch pipe has a first branch pipe end and a second branch pipe end arranged opposite to each other. The first branch pipe end passes through the baffle of the aluminum electrolysis cell and communicates with the second branch pipe end. The second branch pipe end is connected to the exhaust pipe.

[0006] In some embodiments, the flue gas collection hood is arranged side by side with the shell-breaking device of the electrolytic cell, or the flue gas collection hood is fitted over the shell-breaking device.

[0007] In some embodiments, the cross-section of the flue gas collection hood is rectangular or square; And / or, when the cross-section of the flue gas collection hood is rectangular, the long side of the cross-section of the flue gas collection hood is parallel to the short side of the aluminum electrolysis cell, and the short side of the cross-section of the flue gas collection hood is parallel to the long side of the cell.

[0008] In some embodiments, the longitudinal section of the flue gas collection hood is trapezoidal along the short side of its cross-section.

[0009] In some embodiments, the longitudinal section of the flue gas collection hood is a right trapezoid along the short side of its cross-section. When the flue gas collection hood and the shell-breaking device are arranged side by side, the right-angled side of the longitudinal section of the flue gas collection hood is closer to the side of the shell-breaking device. When the flue gas collection hood is fitted outside the casing device, the inclined side of the longitudinal section of the flue gas collection hood is close to the outlet direction of the exhaust pipe.

[0010] In some embodiments, the exhaust pipe has a first end and a second end disposed opposite to each other, the first end being located upstream of the second end, and the inner diameter of the exhaust pipe gradually increases from the first end to the second end.

[0011] In some embodiments, the hole through the baffle of the aluminum electrolysis cell at the first end of the branch pipe is called a through hole, and the cross-sectional area of ​​the second end of the collecting cover is larger than the cross-sectional area of ​​the through hole; And / or, the first end of the collection cover is located above the lowest end of the shell-breaking device of the aluminum electrolytic cell.

[0012] In some embodiments, the flue gas collection hood is welded to the baffle of the electrolytic cell; The collection cover branch pipe is welded to the baffle of the electrolytic cell.

[0013] In some embodiments, the cross-section of the collection hood branch pipe is circular or square.

[0014] In a second aspect of this application, a flue gas collection system for an aluminum electrolysis cell is provided, comprising: The above-mentioned flue gas collection device for aluminum electrolysis cells; The alumina chamber is connected to the outlet of the exhaust pipe of the flue gas collection device for the aluminum electrolysis cell; The dust collector is connected to the outlet of the alumina silo; An induced draft fan is connected to the outlet of the dust collector via a pipeline; and The chimney is connected to the outlet of the induced draft fan.

[0015] A flue gas collection device for an aluminum electrolytic cell, provided according to one or more embodiments of this application, includes at least one high-temperature flue gas collection mechanism connected to the aluminum electrolytic cell and an exhaust pipe connected to the flue gas collection mechanism; the high-temperature flue gas collection mechanism includes a flue gas collection hood and a collection hood branch pipe, the flue gas collection hood having a first collection hood end and a second collection hood end disposed opposite to each other, the inner diameter of the flue gas collection hood gradually increasing from the first collection hood end to the second collection hood end; the flue gas collection hood is disposed inside the electrolytic cell, the first collection hood end being close to the burner in the electrolytic cell and spaced apart from the burner in the electrolytic cell; the collection hood branch pipe has a first branch pipe end and a second branch pipe end disposed opposite to each other, the first branch pipe end penetrating the baffle of the aluminum electrolytic cell and communicating with the second collection hood end, the second branch pipe end communicating with the exhaust pipe.

[0016] Therefore, this application addresses this issue by installing a flue gas collection hood above the burner. The inner diameter of the flue gas collection hood gradually increases from the first end to the second end. The first end of the hood is close to the burner, and as the gas flows through it, the opening at the second end is larger than the opening at the first end, reducing air resistance and facilitating better upward movement of the gas even at lower temperatures. Directly collecting high-temperature gas at the source of flue gas generation—the shell-breaking and feeding point—significantly reduces the intake of ineffective air. The collected flue gas temperature is more than 80°C higher than traditional gas collection structures. This significantly reduces the intake air volume and the energy consumption of the purification system, such as the fan, while ensuring the anode gas collection rate, and provides sufficient conditions for subsequent utilization of flue gas waste heat. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of a flue gas collection device for an aluminum electrolysis cell is shown in one or more embodiments of this application.

[0018] Figure 2 It shows Figure 1 A partial schematic diagram of the flue gas collection device.

[0019] Figure 3 A schematic diagram of a flue gas collection system for an aluminum electrolysis cell is shown in one or more embodiments of this application.

[0020] Explanation of reference numerals in the attached drawings: 100-Flue gas collection device, 110-High temperature flue gas collection mechanism, 111-Flue gas collection hood, 112-Collection hood branch pipe, 120-Exhaust pipe, 200-Aluminum electrolytic cell, 210-Cell body, 220-Electrolytic cell baffle, 230-Shelling device, 240-Fire hole, 250-Covering material, 300-Alumina silo, 400-Dust collector, 500-Fan, 600-Chimney. Detailed Implementation

[0021] To enable those skilled in the art to more clearly understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] Please see Figure 1 and Figure 2 According to a first aspect of this application, a flue gas collection device 100 for an aluminum electrolysis cell 200 is provided, including at least one high-temperature flue gas collection mechanism 110 connected to the aluminum electrolysis cell 200 and a flue gas exhaust pipe 120 connected to the flue gas collection mechanism. The high-temperature flue gas collection mechanism 110 includes: The flue gas collection hood 111 has a first end and a second end that are arranged opposite to each other. The inner diameter of the flue gas collection hood 111 gradually increases from the first end to the second end. The flue gas collection hood 111 is disposed in the electrolytic cell. The first end of the collection hood is close to the flame hole 240 in the electrolytic cell and is spaced apart from the flame hole 240 in the electrolytic cell. The collection hood branch pipe 112 has a first end and a second end that are arranged opposite to each other. The first end of the branch pipe passes through the baffle of the aluminum electrolysis cell 200 and is connected to the second end of the collection hood. The second end of the branch pipe is connected to the exhaust pipe 120.

[0023] The aluminum electrolysis cell 200 includes a cell body 210 and six or more electrolysis components disposed in the cell body 210. Generally, there are six or more electrolysis components. Each electrolysis component includes an electrolysis cell baffle 220, a shell-breaking device 230 connected to the electrolysis cell baffle 220, and a fire hole 240 located below the shell-breaking device 230. The electrolysis cell baffle 220 has a through hole, through which the collection cover branch pipe 112 passes.

[0024] The high-temperature flue gas generated by the fire hole 240 of the aluminum electrolysis cell 200 is usually between 930℃ and 960℃, which is much higher than the temperature of the surrounding flue gas, and the flue gas density is lower than that of the surrounding air.

[0025] The inner diameter of the flue gas collection hood 111 gradually increases from the first end to the second end. This increase can be linear, non-linear, or trapezoidal. This reduces the range of low-temperature air collection and increases the resistance to low-temperature air intake. The first end of the flue gas collection hood 111 has a smaller inner diameter, while the second end has a larger inner diameter. The smaller inner diameter of the first end is closer to the fire eye 240, near the top of the heat source, allowing for capture of the flue gas during the initial diffusion stage, preventing lateral diffusion. The flue gas flows upward within the hood 111, and the volume of the rising channel gradually increases as the hot flue gas rises, providing a smooth upward path and reducing turbulence and energy loss caused by abrupt changes in cross-sectional area.

[0026] The first end of the collecting hood branch pipe 112 is connected to the second end of the flue gas collecting hood 111, so that the flue gas collected by the flue gas collecting hood 111 can be introduced into the exhaust pipe 120 through the collecting hood branch pipe 112, ensuring that the flue gas is discharged through the exhaust pipe 120.

[0027] In some embodiments, the flue gas collection hood 111 is disposed on the upper part of the electrolytic cell, with the first end of the collection hood close to the flame hole 240 inside the electrolytic cell. The distance between the flue gas collection hood 111 and the upper surface of the covering material 250 of the aluminum electrolytic cell 200 ranges from 250mm to 400mm, and can be 250mm, 300mm, 325mm, 350mm, 380mm, or 400mm. High-temperature anode gas from the electrolytic cell discharged from the flame hole 240 is collected by relying on the negative pressure of the exhaust branch pipe and the thermal buoyancy of the exhaust density difference of the flame hole 240. Since the flue gas collection hood 111 and the collection hood branch pipe 112 are embedded within a certain distance from the upper or lower air vent of the shell-breaking device 230, they do not affect the drilling of the flame hole 240 and the addition of raw materials into the cell during normal production, thus meeting the space requirements for anode replacement operations.

[0028] Therefore, this application provides a flue gas collection hood 111 above the flame 240. The inner diameter of the first end of the flue gas collection hood 111 gradually increases towards the second end. The first end of the flue gas collection hood 111 is close to the flame 240. As the gas flows through the flue gas collection hood 111, the opening at the second end of the flue gas collection hood 111 is larger than the opening at the first end, which reduces air resistance and facilitates better upward movement of the gas even when the gas temperature is lower. By directly collecting high-temperature gas at the source of flue gas generation, namely the shell-breaking and feeding point, the ineffective air intake is greatly reduced. The collected flue gas temperature is more than 80°C higher than that of traditional gas collection structures. This significantly reduces the intake air volume and the energy consumption of the purification system, such as the fan, while ensuring the anode gas collection rate, and provides sufficient conditions for subsequent utilization of flue gas waste heat.

[0029] In some embodiments, the inner diameter of the flue gas collection hood 111, the inner diameter of the exhaust pipe 120, and the inner diameter of the collection hood branch pipe 112 can be optimized by computational fluid dynamics based on the distance of each flue gas collection hood 111 from the exhaust pipe 120 and the overall negative pressure, so as to ensure that the high-temperature anode gas collection rate of each fire hole 240 is maximized.

[0030] In other embodiments, the exterior of the collecting hood branch pipe 112 and the exterior of the exhaust pipe 120 may be wrapped with a high-performance thermal insulation material such as an aluminum silicate fiber blanket to ensure that the temperature drop of the flue gas during the transportation process is minimized, for example, less than 50°C.

[0031] In some embodiments, the flue gas collection hood 111 is arranged side by side with the shell-breaking device 230 of the aluminum electrolysis cell 200, or the flue gas collection hood 111 is fitted over the shell-breaking device 230. That is, the flue gas collection hood 111 can wrap around the shell-breaking device 230 or be arranged side by side with the shell-breaking device 230.

[0032] In some embodiments, the flue gas collection hood 111 and the shell-breaking device 230 are arranged side by side, that is, the flue gas collection hood 111 and the shell-breaking device 230 are arranged laterally side by side along the baffle of the electrolytic cell, rather than nested. In this case, the flue gas collection hood 111 and the shell-breaking device 230 are relatively independent units, installed at different positions on the baffle of the electrolytic cell, and are arranged separately. This facilitates separate maintenance of the flue gas collection device 100 and the shell-breaking device 230 in the later stages, saving downtime. When the flue gas collection hood 111 and the shell-breaking device 230 are arranged laterally side by side along the baffle of the electrolytic cell, the first end of the flue gas collection hood 111 is located on the side of the burner 240, which can form a lateral negative pressure zone and effectively capture the laterally escaping flue gas.

[0033] In other embodiments, the smoke collection hood 111 is fitted outside the shell-breaking device 230, that is, the smoke collection hood 111 is nested outside the shell-breaking device 230, and the smoke collection hood 111 wraps around the shell-breaking device 230. In other words, the smoke collection hood 111 can surround and capture the shell-breaking device 230 360° from the first end, preventing the smoke from spreading around and forming precise capture of the smoke.

[0034] In some embodiments, the centerline of the smoke collection hood 111 coincides with the centerline of the fire hole 240, which can collect more smoke.

[0035] In some embodiments, the cross-section of the flue gas collection hood 111 is rectangular or square; that is, the cross-section of the flue gas collection hood 111 is rectangular, which has a larger cross-sectional area than a cylindrical flue gas collection hood 111, thereby improving collection efficiency.

[0036] In some embodiments, when the cross-section of the flue gas collection hood 111 is rectangular, the long side of the cross-section of the flue gas collection hood 111 is parallel to the short side of the tank body 210 of the aluminum electrolysis cell 200, and the short side of the cross-section of the flue gas collection hood 111 is parallel to the long side of the tank body 210. The tank body 210 of the electrolysis cell is a rectangular tank, and six or more electrolysis components are arranged side by side along the long side of the tank body 210. In this case, there will be more low-temperature air along the long side of the electrolysis cell, and more high-temperature flue gas along the short side of the electrolysis cell. Therefore, the long side of the cross-section of the flue gas collection hood 111 is parallel to the short side of the trough 210, meaning that the flue gas collection hood 111 is longer along the short side of the trough 210; the short side of the cross-section of the flue gas collection hood 111 is parallel to the long side of the trough 210, meaning that the flue gas collection hood 111 is relatively shorter along the long side of the trough 210. Given the same height of the flue gas collection hood 111, the area of ​​the longitudinal section of the flue gas collection hood 111 along the short side of the trough 210 is greater than the area of ​​the longitudinal section of the flue gas collection hood 111 along the long side of the trough 210. The longitudinal section of the flue gas collection hood 111 along the direction parallel to the short side of the tank 210 is designated as the first longitudinal section, and the longitudinal section of the flue gas collection hood 111 along the direction parallel to the long side of the tank 210 is designated as the second longitudinal section. The first longitudinal section is close to the flame hole 240 and can absorb more high-temperature flue gas. The second longitudinal section is slightly farther away from the flame hole 240 relative to the first longitudinal section, ensuring the intake of high-temperature flue gas around the flame hole 240 while minimizing the intake of low-temperature gas around the flame hole 240. Therefore, the area of ​​the first longitudinal section is larger than the area of ​​the second longitudinal section, which can quickly collect the high-temperature gas close to the flame hole 240 while reducing the intake of low-temperature air around the flame hole 240.

[0037] In some embodiments, the longitudinal section of the flue gas collection hood 111 is trapezoidal along the short side of its cross-section. Since the open area from the first end to the second end of the flue gas collection hood 111 gradually increases, while ensuring smooth flow of flue gas inside the hood, dust and impurities can slide down the inclined side along the longitudinal direction of the hood 111, preventing them from entering the collection hood branch pipe 112 and the exhaust pipe 120, thereby ensuring smooth collection of high-temperature flue gas by the high-temperature flue gas collection mechanism 110.

[0038] In some embodiments, along the short side of the cross-section of the flue gas collection hood 111, the longitudinal section of the flue gas collection hood 111 is a right-angled trapezoid; the right-angled trapezoid has one vertical side, which facilitates positioning and installation.

[0039] In some embodiments, when the flue gas collection hood 111 and the shell-breaking device 230 are arranged side by side, the right-angled side of the longitudinal section of the flue gas collection hood 111 is close to one side of the shell-breaking device 230; the shell-breaking device 230 has a relatively regular shape, and the right-angled side of the longitudinal section of the flue gas collection hood 111 is close to one side of the shell-breaking device 230, which facilitates positioning and installation with the shell-breaking device 230.

[0040] In some embodiments, when the flue gas collection hood 111 is fitted outside the shell-breaking device 230, the inclined side of the longitudinal section of the flue gas collection hood 111 is close to the outlet direction of the exhaust pipe 120, so that after the flue gas travels upward to the highest point of the flue gas collection hood 111, more flue gas can enter the exhaust pipe 120 through the collection hood branch pipe 112.

[0041] In some embodiments, the exhaust pipe 120 has a first end and a second end of the exhaust pipe disposed opposite to each other, the first end of the exhaust pipe 120 is located upstream of the second end of the exhaust pipe 120, and the inner diameter of the first end of the exhaust pipe 120 gradually increases towards the inner diameter of the second end of the exhaust pipe 120. The aluminum electrolysis cell 200 includes a cell body 210 and six electrolysis components disposed in the cell body 210. The six burners 240 in the six electrolysis components are respectively designated as the first burner 240, the second burner 240, the third burner 240, the fourth burner 240, the fifth burner 240, and the sixth burner 240. The six collection hood branch pipes 112 in the six electrolysis components are respectively designated as the first collection hood branch pipe 112, the second collection hood branch pipe 112, the third collection hood branch pipe 112, the fourth collection hood branch pipe 112, the fifth collection hood branch pipe 112, and the sixth collection hood branch pipe 112. The positions where the first collection hood branch pipe 112, the second collection hood branch pipe 112, the third collection hood branch pipe 112, the fourth collection hood branch pipe 112, the fifth collection hood branch pipe 112, and the sixth collection hood branch pipe 112 are connected to the exhaust pipe 120 are respectively designated as the first connection point, the second connection point, the third connection point, the fourth connection point, the fifth connection point, and the sixth connection point. The flue gas transported by the first collecting hood branch pipe 112 enters the exhaust pipe 120 through the first connecting point. During the flow process, it merges with the flue gas transported by the second collecting hood branch pipe 112 at the second connecting point. The flue gas merging at the second connecting point merges with the flue gas transported by the third collecting hood branch pipe 112 at the third connecting point; the flue gas merging at the third connecting point merges with the flue gas transported by the fourth collecting hood branch pipe 112 at the fourth connecting point; the flue gas merging at the fourth connecting point merges with the flue gas transported by the fifth collecting hood branch pipe 112 at the fifth connecting point; and the flue gas merging at the fifth connecting point merges with the flue gas transported by the sixth collecting hood branch pipe 112 at the sixth connecting point. The inner diameter of the exhaust pipe 120 gradually increases from the first end to the second end. As multiple flue gas streams converge, the inner diameter of the exhaust pipe 120 gradually increases, ensuring that the flue gas is smoothly transported from the first end to the second end of the exhaust pipe 120, thereby improving the exhaust efficiency.

[0042] In some embodiments, the hole through the baffle of the aluminum electrolysis cell 200 at the first end of the branch pipe is called a through hole, and the cross-sectional area of ​​the second end of the flue gas collection hood 111 is larger than the cross-sectional area of ​​the through hole; that is, during the upward process of the flue gas in the flue gas collection hood 111, the flue gas can flow into the collection hood branch pipe 112 through the collection hood branch pipe 112. In addition, some dust and impurities encounter the baffle during the upward process, and the baffle can block the dust and impurities, preventing the dust and impurities from entering the collection hood branch pipe 112.

[0043] In some embodiments, the first end of the flue gas collection hood 111 is located above the lowest end of the shell-breaking device 230. Since the lowest point of the shell-breaking device 230 in the aluminum electrolysis cell 200 becomes thicker and larger during operation due to contact with the electrolyte crust (alumina solidified layer) and the high-temperature electrolyte melt (cryolite-alumina melt), the first end of the flue gas collection hood 111 being located above the lowest end of the shell-breaking device 230 ensures that the first end of the flue gas collection hood 111 is not affected by changes in the shape of the shell-breaking device 230, thereby ensuring flue gas collection efficiency.

[0044] In some embodiments, the flue gas collection hood 111 is welded to the baffle of the aluminum electrolysis cell 200 to ensure the sealing of the connection between the flue gas collection hood 111 and the baffle of the aluminum electrolysis cell 200.

[0045] In some embodiments, the collecting hood branch pipe 112 is welded to the baffle of the aluminum electrolysis cell 200. This ensures the airtightness of the connection between the flue gas collecting hood 111 and the baffle of the aluminum electrolysis cell 200, while also ensuring the communication between the flue gas collecting hood 111 and the collecting hood branch pipe 112.

[0046] In some embodiments, the cross-sectional area of ​​the collecting hood branch pipe 112 is circular or square. That is, the cross-section of the collecting hood branch pipe 112 can be circular or square, as long as the collecting hood branch pipe 112 can ensure the connectivity between the flue gas collecting hood 111 and the exhaust pipe 120.

[0047] In the second aspect of this application, as Figure 3 As shown, a flue gas collection system for an aluminum electrolysis cell 200 is provided, comprising: the aforementioned flue gas collection device for the aluminum electrolysis cell, an alumina silo 300, a dust collector 400, a fan 500, and a chimney 600; the alumina silo 300 is connected to the outlet of the exhaust pipe of the flue gas collection device for the aluminum electrolysis cell, and the outlet of the alumina silo 300 and the exhaust pipe can be connected through the electrolysis cell exhaust pipe or an exhaust manifold outside the electrolysis workshop; the dust collector is connected to the outlet of the alumina silo; the induced draft fan is connected to the outlet of the dust collector through a pipeline; and the chimney 600 is connected to the outlet of the induced draft fan 500. The specific structure of the flue gas collection device for the aluminum electrolysis cell 200 is as described in the above embodiments. Since the flue gas collection system for the aluminum electrolysis cell 200 adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0048] When the aluminum electrolysis cell 200 starts working and needs to absorb the flue gas inside the aluminum electrolysis cell 200, the induced draft fan 500 can be turned on. The induced draft fan 500 can drive the flue gas from the flue gas collection device, the alumina silo 300, and the dust collector 400 into the chimney for discharge.

[0049] The alumina silo can be used as an adsorption reactor to adsorb fluorides in flue gas, achieving the goal of "treating waste with waste"; the dust collector can be a bag filter to achieve gas-solid separation and absorb dust; the induced draft fan provides negative pressure to ensure that the gas can smoothly enter the chimney and be discharged.

[0050] Through the above embodiments, this application has the following beneficial effects or advantages: 1) This application involves installing a flue gas collection hood 111 above the flame 240. The inner diameter of the flue gas collection hood 111 gradually increases from its first end to its second end. The first end of the flue gas collection hood 111 is close to the flame 240. As the gas flows through the flue gas collection hood 111, the opening at the second end of the flue gas collection hood 111 is larger than the opening at the first end, which reduces air resistance and facilitates better upward movement of the gas even when the gas temperature is lower. High-temperature gas is collected directly at the source of flue gas generation, namely the shell-breaking and feeding point, greatly reducing the intake of ineffective air. The collected flue gas temperature is more than 80°C higher than that of traditional gas collection structures. This significantly reduces the intake air volume and the energy consumption of the purification system, such as the fan, while ensuring the anode gas collection rate, and provides sufficient conditions for subsequent utilization of flue gas waste heat.

[0051] 2) The high concentration of carbon dioxide flue gas collected in this application provides favorable conditions for subsequent capture. The high pollutant concentration also improves the purification efficiency, achieving a synergy between energy conservation and emission reduction.

[0052] 3) The flue gas collection hood 111 of this application occupies little space and can be installed alone or in parallel with the purification system. Its operation does not affect the normal production efficiency of the electrolytic cell.

[0053] 4) This application optimizes the design of the flue structure to ensure uniform negative pressure at all points in the pipeline, eliminate dead zones in gas collection, and better balance the overall heat of the electrolytic cell, thereby improving the stability and efficiency of electrolytic cell production.

[0054] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0056] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0057] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0058] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A flue gas collection device for an aluminum electrolysis cell, characterized in that, It includes at least one high-temperature flue gas collection mechanism connected to an aluminum electrolysis cell and a flue gas exhaust pipe connected to the flue gas collection mechanism; The high-temperature flue gas collection mechanism includes: A flue gas collection hood has a first end and a second end of the collection hood arranged opposite to each other, and the inner diameter of the flue gas collection hood gradually increases from the first end to the second end of the collection hood; the flue gas collection hood is disposed in the electrolytic cell, and the first end of the collection hood is close to the flame hole in the electrolytic cell and is spaced apart from the flame hole in the electrolytic cell; The collection hood branch pipe has a first branch pipe end and a second branch pipe end arranged opposite to each other. The first branch pipe end passes through the baffle of the aluminum electrolysis cell and communicates with the second branch pipe end. The second branch pipe end is connected to the exhaust pipe.

2. The flue gas collection device for aluminum electrolysis cells according to claim 1, characterized in that, The flue gas collection hood is arranged side by side with the shell-breaking device of the aluminum electrolytic cell, or the flue gas collection hood is sleeved outside the shell-breaking device.

3. The flue gas collection device for aluminum electrolysis cells according to claim 2, characterized in that, The cross-section of the flue gas collection hood is rectangular or square; And / or, when the cross-section of the flue gas collection hood is rectangular, the long side of the cross-section of the flue gas collection hood is parallel to the short side of the aluminum electrolysis cell, and the short side of the cross-section of the flue gas collection hood is parallel to the long side of the cell.

4. The flue gas collection device for aluminum electrolysis cells according to claim 3, characterized in that, Along the short side of the cross-section of the flue gas collection hood, the longitudinal section of the flue gas collection hood is trapezoidal.

5. The flue gas collection device for aluminum electrolysis cells according to claim 4, characterized in that, Along the short side of the cross-section of the flue gas collection hood, the longitudinal section of the flue gas collection hood is a right trapezoid; When the flue gas collection hood and the shell-breaking device are arranged side by side, the right-angled side of the longitudinal section of the flue gas collection hood is closer to the side of the shell-breaking device. When the flue gas collection hood is fitted outside the casing device, the inclined side of the longitudinal section of the flue gas collection hood is close to the outlet direction of the exhaust pipe.

6. The flue gas collection device for an aluminum electrolytic cell according to any one of claims 1-5, characterized in that, The exhaust pipe has a first end and a second end that are arranged opposite to each other. The first end is located upstream of the second end, and the inner diameter of the exhaust pipe gradually increases from the first end to the second end.

7. The flue gas collection device for aluminum electrolysis cells according to any one of claims 1-5, characterized in that, The hole at the first end of the branch pipe that penetrates the baffle of the aluminum electrolysis cell is called a through hole, and the cross-sectional area of ​​the second end of the collection cover is larger than the cross-sectional area of ​​the through hole. And / or, the first end of the collection cover is located above the lowest end of the shell-breaking device of the aluminum electrolytic cell.

8. The flue gas collection device for an aluminum electrolytic cell according to any one of claims 1-5, characterized in that, The flue gas collection hood is welded to the baffle of the aluminum electrolytic cell; The collection cover branch pipe is welded to the baffle of the aluminum electrolysis cell.

9. The flue gas collection device for an aluminum electrolytic cell according to any one of claims 1-5, characterized in that, The cross-section of the collection hood branch pipe is circular or square.

10. A flue gas collection system for an aluminum electrolysis cell, characterized in that, include: The flue gas collection device for aluminum electrolysis cells according to any one of claims 1-9; The alumina chamber is connected to the outlet of the exhaust pipe of the flue gas collection device for the aluminum electrolysis cell; The dust collector is connected to the outlet of the alumina silo; An induced draft fan is connected to the outlet of the dust collector via a pipeline; as well as The chimney is connected to the outlet of the induced draft fan.

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