Multi-stage regulation concentration and dilution separation device

Abstract

This invention discloses a multi-stage adjustable concentration separation device, comprising: a bent tube body, a logarithmic spiral baffle, and a two-stage concentration assembly. The bent tube body includes a separation tube section, a primary concentration tube section, a dense phase tube section, and a dilute phase tube section. The logarithmic spiral baffle is disposed within the primary concentration tube section to define the dense phase flow channel and the dilute phase flow channel. The logarithmic spiral baffle has multiple concentration sections, each including an exhaust port and a hinge. The hinge is rotatably disposed at the exhaust port. Filter holes are provided on the peripheral wall of the dense phase tube section. The two-stage concentration assembly includes a filter screen and a housing. The filter screen is disposed within the filter holes. The housing has an extraction chamber and an extraction port, the extraction chamber communicating with the filter holes. Thus, the dense phase airflow sequentially passes through multiple concentration sections for primary concentration, improving the powder concentration. The dense phase airflow can also pass through the two-stage concentration assembly for secondary concentration, further improving the concentration effect. The logarithmic spiral baffle is used to reduce the frictional resistance of the dense phase airflow during the concentration process.

Description

Technical Field

[0001] This invention relates to the field of burner technology, and more particularly to a multi-stage adjustable concentration-lean separation device. Background Technology

[0002] Pneumatic conveying is a common method for conveying powders in industry. In combustion applications, increasing the concentration of powders (such as pulverized coal) is beneficial for burner ignition and stable combustion. However, the solid-to-gas ratio in the conveying air of traditional power plant boilers is low. Related technologies utilize the inertia of the powder, using bends to enrich the powder on the outside of the bend, and then separating the high- and low-concentration two-phase flows using baffles. The denser phase stream is then connected to the burner to improve combustion efficiency and stability. However, relying solely on the inertia of the powder results in only a small difference in the flow rates of the two airflows, and the enrichment efficiency is limited. For example, with an inlet solid-to-gas ratio of 0.4 kg / kg, the concentration on the denser phase side after branching typically reaches 0.6 kg / kg, rarely exceeding 0.8 kg / kg.

[0003] Furthermore, some powder-using equipment requires very small gas flow rates but has high requirements for the solid-to-gas ratio. For example, the required dense phase gas volume is only 5-10% of the total gas volume, but the solid-to-gas ratio needs to be increased to 2-5 times the original. In related technologies, multi-stage series combination of dense and desiccant separation structures is used to enable secondary enrichment of the dense phase branch. However, the enrichment efficiency and stability of the second stage are significantly reduced, making it difficult to meet the requirements of equipment with high stability requirements, such as burners. Moreover, the resistance of the second stage is more than 4 times that of the first stage. At the same time, under this operating condition, due to the high solid-to-gas ratio, the subsequent resistance on the dense phase side increases significantly, causing the total resistance on the dense phase side to exceed the driving force provided by the original gas flow. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a multi-stage adjustable concentration separation device, which features good concentration effect and precise control of gas flow rate and powder flow rate on the concentrated phase side.

[0006] The multi-stage adjustable concentration-degradation separation device of this invention includes: a bent tube body, a logarithmic spiral baffle, and a two-stage concentration assembly. The bent tube body includes a separation tube section, a first-stage concentration tube section, a concentrated phase tube section, and a dilute phase tube section. The separation tube section is connected to the first-stage concentration tube section. The first-stage concentration tube section is connected to the concentrated phase tube section and the dilute phase tube section, respectively. The logarithmic spiral baffle is disposed inside the first-stage concentration tube section. The logarithmic spiral baffle defines a concentrated phase flow channel and a dilute phase flow channel in the first-stage concentration tube section. The concentrated phase flow channel is connected to the concentrated phase tube section, and the dilute phase flow channel is connected to the dilute phase tube section. The logarithmic spiral baffle... The assembly has multiple enrichment sections, which are spaced apart along the direction of rotation of the logarithmic spiral partition. Each enrichment section includes an exhaust port and a hinge. The hinge is rotatably disposed at the exhaust port and is located within the concentrated phase flow channel. The hinge includes a connected sealing section and an anti-backflow section, with the anti-backflow section located downstream of the sealing section. The peripheral wall of the concentrated phase tube is provided with filter holes. The secondary enrichment assembly includes a filter screen and a housing. The filter screen is disposed within the filter holes, and the housing is disposed on the peripheral wall of the concentrated phase tube. The housing has an extraction chamber and an extraction port communicating with the extraction chamber. The extraction chamber is also communicating with the filter holes.

[0007] The multi-stage concentration separation device of this invention, through which the concentrated phase gas flow exiting the separation tube sequentially passes through multiple concentration sections for primary concentration, thereby increasing the powder concentration. Furthermore, after passing through the primary concentration tube, the concentrated phase gas flow enters the secondary concentration tube section and undergoes secondary concentration through a secondary concentration assembly, further enhancing the concentration effect. In addition, the baffle is configured as a logarithmic spiral structure to reduce the frictional resistance of the concentrated phase gas flow during the concentration process within the primary concentration tube section.

[0008] In some embodiments, the opening angle of the hinge is in the range of 0-40°.

[0009] In some embodiments, the plurality of concentration sections are sequentially defined as a first concentration section, a second concentration section, ..., an Nth concentration section in the direction from upstream to downstream. The vent hole and the hinge of the first concentration section are respectively the first vent hole and the first hinge, and so on. The vent hole and the hinge of the Nth concentration section are respectively the Nth vent hole and the Nth hinge, and the maximum opening angle of the hinge is α, satisfying: α n-1 >a n , n=2, 3...N.

[0010] In some embodiments, the length of the sealing section is the same as the cross-sectional length of the corresponding vent hole, the total length of the hinge is a constant, the length of the anti-backflow section is c, and the length of the sealing section is d, satisfying: c n-1 / (c n-1 +d n-1 ) < cn / (c n +d n ), n=2, 3...N.

[0011] In some embodiments, the maximum opening height of the Nth leaf is b. n The cross-sectional height of the dense phase flow channel at the Nth concentration section is h. n Satisfying: b n ≤0.3h n , n=2, 3...N.

[0012] In some embodiments, the structure of the logarithmic spiral partition satisfies: x = R × e tcotθ ×cost, t∈(t1,t2); y=R×e tcotθ ×sint,t∈(t1,t2); where R is the radius of curvature of the first-stage concentration tube section, and the radius of curvature of the separation tube section is the same as that of the first-stage concentration tube section, t is the polar angle at any position on the logarithmic spiral partition, t1 is the angle of the upstream end of the logarithmic spiral partition, and t2 is the angle of the downstream end of the logarithmic spiral partition.

[0013] In some embodiments, the difference between t2 and t1 ranges from 20 to 90°, and θ ranges from 70 to 88°.

[0014] In some embodiments, the cross-sectional area of ​​the dense phase flow channel gradually decreases from upstream to downstream.

[0015] In some embodiments, the cross-sectional area of ​​the dense phase flow channel at angle t is A, satisfying: dA / dt=k, where k is a constant.

[0016] In some embodiments, the secondary concentration assembly further includes an acoustic generator disposed in the extraction chamber. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a multi-stage concentration-degradation separation device according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 Schematic diagram of the cross section of AA.

[0019] Figure 3 This is a schematic diagram of the first-stage concentration tube section of the multi-stage adjustable concentration-degradation separation device according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the airflow distribution in the hinge section of the multi-stage adjustable concentration-depression separation device according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the polar angle of the logarithmic spiral partition of the multi-stage adjustable concentration separation device according to an embodiment of the present invention.

[0022] Figure label:

[0023] 1. Bent pipe body; 11. Separation pipe section; 12. First-stage concentration pipe section; 121. Dense phase flow channel; 122. Dilute phase flow channel; 13. Dense phase pipe section; 14.

[0024] Logarithmic spiral baffle 2, concentration section 21, vent 211, hinge 212, sealing section 2121, anti-backflow section 2122

[0025] Secondary concentration component 3, filter screen 31, housing 32, air extraction chamber 321, air extraction port 322, sound wave generator 33. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The multi-stage concentration-degradation separation device according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0028] like Figures 1 to 5 As shown, the multi-stage concentration-degradation separation device of this invention includes: a bent tube body 1, a logarithmic spiral partition 2, and a two-stage concentration enhancement component 3.

[0029] The bent tube body 1 includes a separation tube section 11, a first-stage concentration tube section 12, a dense phase tube section 13, and a dilute phase tube section 14. The separation tube section 11 is connected to the first-stage concentration tube section 12, and the first-stage concentration tube section 12 is connected to both the dense phase tube section 13 and the dilute phase tube section 14. A logarithmic spiral baffle 2 is disposed inside the first-stage concentration tube section 12, defining a dense phase flow channel 121 and a dilute phase flow channel 122 within the first-stage concentration tube section 12. The dense phase flow channel 121 is connected to the dense phase tube section 13, and the dilute phase flow channel 122 is connected to the dilute phase tube section 14.

[0030] Optionally, such as Figure 1 and Figure 2 As shown, the downstream end of the separation tube section 11 is connected to the upstream end of the first-stage concentration tube section 12. The logarithmic spiral partition 2 divides the first-stage concentration tube section 12 into upper and lower parts. The downstream end of the upper dense phase flow channel 121 is connected to the upstream end of the dense phase tube section 13, and the downstream end of the lower dilute phase flow channel 122 is connected to the upstream end of the dilute phase tube section 14.

[0031] Understandably, upstream and downstream are defined according to the gas flow direction. After the uniform gas-solid two-phase flow enters the separation tube 11, the powder concentration in the gas flow outside the separation tube 11 is relatively high due to the inertia of the powder. Under the action of the logarithmic spiral baffle 2, the dense phase gas flow enters the dense phase tube 13 through the dense phase flow channel 121, and the dilute phase gas flow enters the dilute phase tube 14 through the dilute phase flow channel 122. Furthermore, the upstream position of the logarithmic spiral baffle 2 should ensure that the amount of powder entering the dense phase flow channel 121 is at least 1.2 times the required powder mass flow rate for the dense phase.

[0032] The logarithmic spiral partition 2 has multiple enrichment sections 21, which are spaced apart along the spiral direction of the logarithmic spiral partition 2. Each enrichment section 21 includes an exhaust port 211 and a hinge 212. The hinge 212 is rotatably disposed at the exhaust port 211 and is located within the dense phase flow channel 121. The hinge 212 includes a connected sealing section 2121 and an anti-backflow section 2122, with the anti-backflow section 2122 located downstream of the sealing section 2121.

[0033] Optionally, such as Figures 1 to 4 As shown, the logarithmic spiral partition 2 is also provided with multiple placement slots located downstream of the vent holes 211. The multiple placement slots correspond one-to-one with and are connected to the multiple vent holes 211. When the hinge 212 is closed, the sealing section 2121 is located inside the vent hole 211, and the anti-backflow section 2122 is located inside the placement slot.

[0034] It is understandable that, such as Figure 4 As shown, when the dense phase gas flows through the hinge 212, part of the carrier gas enters the dilute phase flow channel 122 through the exhaust port 211. When the powder passes through the protrusion composed of the anti-backflow section 2122 and the sealing section 2121, most of the powder will be lifted up and enter the subsequent gas flow due to inertia, while a small portion of the powder will leak into the dilute phase flow with the carrier gas. Thus, the powder concentration in the dense phase flow channel 121 increases with each hinge 212, thereby increasing the powder concentration through the first-stage concentration pipe section 12 to more than three times the original concentration.

[0035] For example, such as Figure 4 As shown in the figure, the dashed white arrows refer to powder and air, the solid white arrows refer to powder, and the black arrows refer to air.

[0036] Furthermore, the multi-stage concentration separation device of this invention uses a logarithmic spiral partition 2 as the partition plate, thereby reducing the frictional resistance between the powder and the inner wall of the first-stage concentration tube 12.

[0037] Furthermore, the peripheral wall of the concentrated phase tube section 13 is provided with filter holes, and the secondary concentration component 3 includes a filter screen 31 and a housing 32. The filter screen 31 is disposed in the filter holes, and the housing 32 is disposed on the peripheral wall of the concentrated phase tube section 13. The housing 32 has an extraction chamber 321 and an extraction hole 322 communicating with the extraction chamber 321. The extraction chamber 321 is also communicating with the filter holes.

[0038] In this process, the dense phase gas flow passes through multiple enrichment sections 21 for multi-stage enrichment before entering the dense phase tube section 13. An external suction fan is connected to the suction port 322, allowing the carrier gas to pass through the filter screen 31 into the suction chamber 321, and then exit through the suction port 322. The powder, prevented from entering the suction chamber 321 by the filter screen 31, achieves a two-stage enrichment effect.

[0039] Therefore, in the multi-stage concentration separation device of this embodiment, the concentrated phase airflow exiting the separation tube 11 is sequentially concentrated through multiple concentration sections 21 to achieve the effect of increasing powder concentration. Furthermore, after the concentrated phase airflow passes through the primary concentration tube 12 and enters the concentrated phase tube 13, it can undergo secondary concentration through the secondary concentration assembly 3 to further improve the concentration effect. In addition, the baffle is configured as a logarithmic spiral structure to reduce the frictional resistance of the concentrated phase airflow during the concentration process within the primary concentration tube 12.

[0040] In some embodiments, the opening angle of the hinge 212 ranges from 0 to 40°. It can be understood that after the hinge 212 is flipped toward the dense phase flow channel 121, the maximum angle between the hinge 212 and the logarithmic spiral partition 2 is 40°.

[0041] In some embodiments, a plurality of concentration sections 21 are sequentially defined as a first concentration section, a second concentration section, ..., an Nth concentration section in the direction from upstream to downstream. The vent 211 and the hinge 212 of the first concentration section are respectively the first vent and the first hinge, and so on. The vent 211 and the hinge 212 of the Nth concentration section are respectively the Nth vent and the Nth hinge, and the maximum opening angle of the hinge 212 is α, satisfying: α n-1 >a n , n=2, 3...N.

[0042] Specifically, such as Figures 1 to 3 As shown, there are three concentration sections 21, which are named as the first concentration section, the second concentration section, and the third concentration section from upstream to downstream. The maximum opening angle of the first sheet is greater than that of the second sheet, and the maximum opening angle of the second sheet is greater than that of the third sheet.

[0043] Understandably, due to the maximum opening angle α of the loose-leaf 212... nThe larger the volume of gas, the higher the exhaust volume through the exhaust port 211 and the higher the proportion of powder in the exhaust. Furthermore, the velocity of the dense phase gas flow is relatively low when it first enters the dense phase flow channel 121. As a result, the opening of the upstream hinge 212 (first hinge) is larger (40°). After being accelerated and enriched by the upstream hinge 212, the velocity of the dense phase gas flow increases, and the coal powder becomes more concentrated. The opening of the downstream hinge 212 decreases.

[0044] In addition, during the concentration process in the dense phase flow channel 121, the first hinge, the second hinge, and the third hinge are opened in sequence to precisely increase the concentration of pulverized coal.

[0045] In some embodiments, such as Figure 3 As shown, the length of the sealing section 2121 is the same as the cross-sectional length of its corresponding exhaust port 211. The total length of the hinge 212 is a constant. The length of the anti-backflow section 2122 is c, and the length of the sealing section 2121 is d, satisfying: c n-1 / (c n-1 +d n-1 ) < c n / (c n +d n ), n=2, 3...N.

[0046] For a single hinge 212, the ideal operating condition is to maximize airflow while minimizing powder flow. With a fixed total length of hinge 212, the length d of the sealing section 2121... n A higher proportion allows for the discharge of more air, but this also increases the proportion of powder in the discharged air. Because the total flow rate of the two-phase flow decreases and the powder concentration increases closer to the downstream region in the dense phase flow channel 121, the cross-sectional length of the first exhaust port is greater than that of the second exhaust port, and the cross-sectional length of the second exhaust port is greater than that of the third exhaust port.

[0047] Specifically, such as Figure 3 As shown, the length of the first sealing section 2121 of the first hinge is greater than the length of the first anti-backflow section 2122, the length of the second sealing section 2121 of the second hinge is nearly equal to the length of the second anti-backflow section 2122, and the length of the third sealing section 2121 of the third hinge is less than the length of the third anti-backflow section 2122.

[0048] In some embodiments, such as Figure 3 As shown, the maximum opening height of the Nth hinge is b. n The cross-sectional height of the concentrated phase flow channel 121 at the Nth concentration section is h. n Satisfying: b n ≤0.3h n , n=2, 3...N.

[0049] Understandably, when hinge 212 is opened, if its height occupies too much area of ​​the dense phase flow channel 121, the airflow will undergo a significant acceleration and deceleration process, resulting in vortex dissipation and thus generating additional drag. For example, as... Figure 3 As shown, when the third hinge is opened to its maximum, b3 ≤ 0.3h3.

[0050] In some embodiments, the structure of the logarithmic spiral partition 2 satisfies: x = R × e tcotθ ×cost, t∈(t1,t2); y=R×e tcotθ ×sint, t∈(t1,t2). Where R is the radius of curvature of the first-stage enrichment tube section 12, and the radius of curvature of the separation tube section 11 is the same as that of the first-stage enrichment tube section 12. t is the polar angle at any position on the logarithmic spiral partition 2, t1 is the angle at the upstream end of the logarithmic spiral partition 2, and t2 is the angle at the downstream end of the logarithmic spiral partition 2.

[0051] Among them, such as Figure 5 As shown, t refers to the angle between the line connecting any point on the logarithmic spiral partition 2 and the center point of the first-stage concentration tube section 12, and the X-axis; the corresponding θ is the angle between the line connecting that point and the center point and the tangent at that point. Specifically, as... Figure 2 and Figure 3 As shown, t2 > t1. Since the outer side of the dense phase flow channel 121 is a powder enrichment region, the friction between the powder and the wall surface is a significant source of resistance within the dense phase flow channel 121. Therefore, to reduce this resistance, the structure of the baffle follows a logarithmic spiral structure.

[0052] Furthermore, the difference between t2 and t1 ranges from 20 to 90°. θ determines the degree to which the logarithmic spiral deviates from a circle; considering both processing difficulty and separation effect, θ ranges from 70 to 88°.

[0053] In some embodiments, the cross-sectional area of ​​the dense phase flow channel 121 gradually decreases from upstream to downstream. That is, the dense phase flow channel 121 gradually contracts from upstream to downstream, thereby increasing the velocity of the dense phase gas flow. Specifically, the cross-sectional area of ​​the dense phase flow channel 121 at angle t is A, which satisfies: dA / dt=k, where k is a constant.

[0054] In some embodiments, such as Figure 2 As shown, the secondary concentration component 3 also includes a sound wave generator 33, which is located inside the extraction chamber 321.

[0055] Understandably, the sound wave generator 33 is used to vibrate the filter 31, removing the powder adhering to its surface to ensure unobstructed airflow. Furthermore, because the powder concentration rapidly increases within the dense phase tube section 13, some highly adhesive powders may agglomerate, hindering subsequent transport and use. By periodically adjusting the sound wave vibration frequency within a certain range, resonance is induced in the agglomerated powder within the dense phase tube section 13, thereby breaking up the powder agglomeration and restoring it to a loose state.

[0056] In the description of this invention, 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," "counterclockwise," "axial," "radial," and "circumferential" 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 invention and simplifying the description, and are not intended to 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 invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0058] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0060] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A multi-stage concentration-to-dilute separation device, characterized in that, include: The bent tube body includes a separation tube section, a primary concentration tube section, a dense phase tube section, and a dilute phase tube section. The separation tube section is connected to the primary concentration tube section, and the primary concentration tube section is connected to the dense phase tube section and the dilute phase tube section, respectively. A logarithmic spiral baffle is disposed within the primary enrichment tube section. The logarithmic spiral baffle defines a concentrated phase flow channel and a dilute phase flow channel within the primary enrichment tube section. The concentrated phase flow channel is connected to the concentrated phase tube section, and the dilute phase flow channel is connected to the dilute phase tube section. The logarithmic spiral baffle has multiple enrichment sections, which are spaced apart along the spiral direction of the logarithmic spiral baffle. Each enrichment section includes an exhaust port and a hinge. The hinge is rotatably disposed at the exhaust port and is located within the concentrated phase flow channel. The hinge includes a connected sealing section and an anti-backflow section, with the anti-backflow section located downstream of the sealing section. A secondary concentration assembly is provided with filter holes on the peripheral wall of the concentrated phase tube. The secondary concentration assembly includes a filter screen and a housing. The filter screen is disposed in the filter holes, and the housing is disposed on the peripheral wall of the concentrated phase tube. The housing has an extraction chamber and an extraction hole communicating with the extraction chamber. The extraction chamber is also communicating with the filter holes.

2. The multi-stage concentration-degradation separation device according to claim 1, characterized in that, The opening angle range of the hinge is 0-40°.

3. The multi-stage concentration-to-dilute separation device according to claim 2, characterized in that, A plurality of said concentration sections are sequentially defined as a first concentration section, a second concentration section, …, an Nth concentration section in the direction from upstream to downstream, the exhaust hole and the hinge of said first concentration section are respectively a first exhaust hole and a first hinge, and so on, the exhaust hole and the hinge of said Nth concentration section are respectively an Nth exhaust hole and an Nth hinge, the maximum opening angle of said hinge is a, and the following conditions are met: a n-1 > a n , n = 2, 3, …, N.

4. The multi-stage concentration-to-dilute separation device according to claim 3, characterized in that, The length of the sealing section is the same as the cross-sectional length of the corresponding exhaust hole. The total length of the hinge is a constant. The length of the anti-backflow section is c, and the length of the sealing section is d, satisfying: c n-1 / (c n-1 +d n-1 ) < c n / (c n +d n ), n=2, 3...N.

5. The multi-stage concentration-to-dilute separation device according to claim 4, characterized in that, The maximum opening height of the Nth movable page is b. n The cross-sectional height of the dense phase flow channel at the Nth concentration section is h. n Satisfying: b n ≤0.3h n , n=2, 3...N.

6. The multi-stage concentration-degradation separation device according to claim 5, characterized in that, The structure of the logarithmic spiral partition satisfies: x = R × e tcotθ ×cost, t∈(t1,t2); y=R×e tcotθ ×sint,t∈(t1,t2); where R is the radius of curvature of the first-stage concentration tube section, and the radius of curvature of the separation tube section is the same as that of the first-stage concentration tube section; t is the polar angle at any position on the logarithmic spiral partition; t1 is the angle of the upstream end of the logarithmic spiral partition; t2 is the angle of the downstream end of the logarithmic spiral partition; θ is the angle between the line connecting any point on the logarithmic spiral partition and the center point and the tangent at that point.

7. The multi-stage concentration-degradation separation device according to claim 6, characterized in that, The difference between t2 and t1 ranges from 20 to 90°, and θ ranges from 70 to 88°.

8. The multi-stage concentration-to-dilute separation device according to claim 6, characterized in that, The cross-sectional area of ​​the dense phase flow channel gradually decreases from upstream to downstream.

9. The multi-stage concentration-degradation separation device according to claim 8, characterized in that, The cross-sectional area of ​​the dense phase flow channel at angle t is A, which satisfies: dA / dt=k, where k is a constant.

10. The multi-stage concentration-degradation separation device according to any one of claims 1-9, characterized in that, The secondary concentration assembly also includes a sound wave generator, which is located in the extraction chamber.

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