Cascade separation apparatus and separation method for mixing gases

Abstract

The present application relates to the technical field of fluid separation, and in particular to a cascade separation device for mixed gas, comprising a coaxial rotating first separation cavity, a second separation cavity arranged at the radial far end of the first separation cavity, and a rotating drum penetrating in the first separation cavity, wherein the first separation cavity is in the shape of a rotary body, the tangent line of any point on the inner wall of the first separation cavity and the axis of the rotating shaft in the same plane is less than 90 degrees, the first separation cavity is internally provided with a flow guide for guiding the mixed gas to the second separation cavity and a plurality of blades for making the mixed gas in a laminar flow state, the separation device is simple in structure, small in size, and low in energy consumption, and can meet the use requirements in multiple fields. Meanwhile, the present application also relates to a separation method, which uses the above separation device and is based on four physical mechanisms, i.e. the action of strong centrifugal force, stratified flow, making the mixed gas in a laminar flow state, and inhibiting the Brownian motion, to realize the separation of the mixed gas, and greatly improve the separation efficiency and separation effect.

Description

Technical Field

[0001] This invention relates to the field of fluid separation technology, and in particular to a cascade separation device and method for mixed gases. Background Technology

[0002] Currently, there is an urgent need for the separation of mixed gases in many fields, such as coal chemical production, biogas desulfurization, mining, natural gas heavy hydrocarbon removal, and power plant tail gas pollutant separation. However, traditional gas separation equipment is large in size, energy-intensive, short in life, and achieves relatively low purity after gas separation. Traditional centrifugal separation equipment generally simply places the mixed gas in a high-speed rotating centrifuge. Based on the different centrifugal forces generated at different radial positions by the mixed fluids of different densities, different gas components are separated into layers at different radii, thus separating the different gas components. However, when the fluid flows at high speed, the mixed gas is prone to turbulence. At the same time, due to the influence of Brownian motion, the different gas components tend to remix. The collision between the gas far from the axis and the wall also generates relative motion, forming turbulence. The greater the relative motion, the higher the Reynolds number, and the more severe the disturbance, which will further aggravate the remixing of the separated gases. The mixing phenomenon caused by the above reasons seriously affects the separation effect and may even prevent effective separation. Existing patent CN117259031A discloses a fluid centrifugal separator. Although it has been optimized by setting up blades and a retention chamber, the gas near the inner wall of the device is still disturbed by collisions, and the gas separated in the retention chamber is also very easy to remix, so the effect is not ideal. There are also methods that improve the separation effect by controlling the gas flow rate within a small range to minimize gas disturbance, but this also significantly reduces the separation efficiency. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a cascade separation device and separation method for mixed gases, which solves the technical problems of large size, low efficiency and poor separation effect of traditional separation equipment.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0007] In a first aspect, embodiments of the present invention provide a cascade separation device for a mixed gas, comprising a rotating unit and a stationary unit. The rotating unit includes a first separation chamber that rotates coaxially, a second separation chamber disposed at the radially distal end of the first separation chamber, and a rotating cylinder that penetrates the interior of the first separation chamber. The first separation chamber has a rotating body structure, and the angle between the tangent at any point on its inner wall and the axis of rotation in the same plane is less than 90 degrees. The first separation chamber is provided with a guide element for guiding the mixed gas to the second separation chamber and several blades for keeping the mixed gas in a laminar flow state. The guide element divides the first separation chamber into a pressurization separation chamber and an expansion separation chamber that are interconnected, and divides the rotating cylinder into a first chamber and a second chamber that are not interconnected.

[0008] The stationary unit includes a mixed gas inlet and a first gas outlet connected to both ends of the rotating drum, and a second gas outlet connected to the second separation chamber.

[0009] The inside of the rotating drum forms a first separation chamber that connects the inlet of the mixed gas and the outlet of the first gas.

[0010] Optionally, the second separation chamber is an annular structure perpendicular to the axial direction of the rotating cylinder and sleeved on the outer wall of the first separation chamber. The radial distance from the inner wall of the second separation chamber on the side away from the first separation chamber to the outer wall of the first separation chamber gradually increases along the direction from the mixed gas inlet to the first gas outlet. Several drainage conduits communicating with the second gas outlet are provided in the radially distal region of the second separation chamber near the first gas outlet, and several return pipes are provided in the radially proximal region near the mixed gas inlet to allow the mixed gas in the second separation chamber to flow back to the inlet of the first separation chamber.

[0011] Optionally, the rotating drum also has a third chamber that is not connected to the second chamber, and the third chamber is located at the end of the second chamber away from the guide member. The end of the first chamber away from the second chamber is connected to the mixed gas inlet, and the peripheral wall of the first chamber has several through holes that communicate with the pressurization separation chamber; the end of the second chamber away from the first chamber is connected to a first gas outlet pipe that communicates with the first gas outlet, and the first gas outlet pipe is installed through the third chamber, and the peripheral wall of the second chamber has several through holes that communicate with the expansion separation chamber; the end of the third chamber away from the second chamber is connected to the second gas outlet, and the guide tube passes through the peripheral wall of the third chamber and communicates with its interior.

[0012] Optionally, the second separation chamber is provided with multiple layers of layered structures with several micropores along the circumferential direction to suppress Brownian motion, so as to slow down the remixing of the separated gases.

[0013] Optionally, the blade is arranged vertically on the inner wall of the first separation chamber along the axial direction and penetrates the pressurization separation chamber and the expansion separation chamber to form multiple gas laminar flow channels between adjacent blades. A channel for the flow of mixed gas is left between the radial distal end of the blade and the second separation chamber.

[0014] Optionally, the blades are of different sizes, and blades of different sizes are alternately arranged, and the distance from the radial proximal end of the blades of different sizes to the rotating drum is different.

[0015] Optionally, the draining member is a plate-shaped member that is vertically arranged and extends through the rotating drum, so as to separate the first separation chamber and the rotating drum into a pressurization separation chamber and an expansion separation chamber, and the first chamber and the second chamber respectively, and the draining member is located in the middle of the axial direction of the second separation chamber.

[0016] Optionally, the thickness of the drainage component gradually decreases from the center to the edge, and its two opposite sides facing the pressurization separation chamber and the expansion separation chamber are concave. The central area of ​​the drainage component is provided with a straight section for the transition from the maximum thickness to the surrounding area.

[0017] Optionally, a supporting housing is fitted around the rotating unit, and the stationary unit is fixedly connected to the supporting housing. The rotating unit and the stationary unit are in dynamic sealing contact. A motor is provided at one end of the supporting housing near the gas mixture inlet. The motor is connected to the rotating drum through a gear transmission mechanism to drive the rotating unit, including the rotating drum, to rotate.

[0018] Secondly, embodiments of the present invention provide a method for separating a mixed gas, using the separation equipment described in any of the above claims to separate the mixed gas, wherein the first gas is a light component gas and the second gas is a heavy component gas, specifically including the following steps:

[0019] S1: The mixed gas enters the pressurized separation chamber in the first separation chamber through the mixed gas inlet and the rotating drum. Based on the action of centrifugal force and the environment of laminar flow and wall adhesion effect, the first gas and the second gas are separated into layers, and the primary separation is completed.

[0020] S2: The mixed gas after primary separation moves towards the second separation chamber under the guidance of the guide element. The second gas flows along the inner wall of the pressurized separation chamber, entering it in large quantities. The first gas is displaced by the second gas and cannot flow along the inner wall of the pressurized separation chamber; only a small amount of the first gas enters the second separation chamber. The remaining mixed gas, containing a large amount of the first gas and a small amount of the second gas, enters the expansion separation chamber within the first separation chamber.

[0021] S3: The mixed gas entering the expansion separation chamber further achieves stratified flow under the action of centrifugal force. Some of the second gas flows against the wall and enters the second separation chamber, further increasing the concentration of the first gas in the expansion separation chamber, completing the secondary separation of the first gas. The separated first gas flows forward and is discharged through the first gas outlet.

[0022] S4: The mixed gas that enters the second separation chamber through steps S2 and S3 completes the secondary separation of the second gas based on the action of centrifugal force and the Brownian motion suppression environment. A large amount of the second gas accumulates at the radial distal end of the second separation chamber, while the remaining gas is squeezed to the radial proximal region of the second separation chamber by the second gas. The separated second gas is then discharged through the second gas outlet, and the remaining gas returns to the pressurized separation chamber for re-circulation and separation.

[0023] (III) Beneficial Effects

[0024] The beneficial effects of this invention are:

[0025] This invention discloses a cascade separation device for mixed gases, which divides a first separation chamber into an interconnected pressurization separation chamber and an expansion separation chamber to perform two separations on the mixed gas. A second separation chamber is located at the radially distal end of the first separation chamber to further purify and separate the heavy component gas separated from the first separation chamber. The first separation chamber is equipped with blades to maintain laminar flow of the mixed gas, preventing remixing. The angle between any point on the inner wall of the first separation chamber and the axis is less than 90 degrees, allowing the separated heavy component gas to adhere to the wall and move along the wall of the first separation chamber towards the second separation chamber. This separation device has a simple structure, small size, and low energy consumption, meeting the needs of multiple fields.

[0026] On the other hand, by using the above-mentioned separation equipment and based on four physical mechanisms—strong centrifugal force, stratified flow, and the environment in which the mixed gas at high flow rates is in a laminar state and Brownian motion is suppressed—the separation of light and heavy components in the mixed gas is achieved, which greatly improves the separation efficiency and separation effect. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the appearance of an embodiment 1 of the cascade separation device for mixed gases according to the present invention;

[0028] Figure 2 for Figure 1 A cross-sectional schematic diagram of the separation equipment in the diagram;

[0029] Figure 3 for Figure 1 A schematic diagram of the blade distribution in the separation equipment;

[0030] Figure 4 for Figure 1 A schematic diagram of the separation device with its supporting housing.

[0031] Figure 5 for Figure 1 A cross-sectional schematic diagram of the separation device with a supporting housing;

[0032] Figure 6 for Figure 1 A schematic diagram showing the angle between the outer wall of the first separation chamber and the axis of the separation device.

[0033] Figure 7 for Figure 1 A schematic diagram illustrating the force analysis of gas molecules in the first separation chamber of the separation device.

[0034] Figure 8 for Figure 1 A schematic diagram of the structure of the second separation chamber of the separation device in the diagram;

[0035] Figure 9 This is a schematic diagram of the flow guide of an embodiment 2 of the cascade separation device for mixed gases according to the present invention.

[0036] [Explanation of Labels in the Attached Image]

[0037] 1: First separation chamber; 101: Pressurization separation chamber; 102: Expansion separation chamber;

[0038] 2: Second separation chamber; 21: L-shaped inclined cover plate; 22: Proximal small plate; 23: Distal small plate; 24: Distal end plate; 25: Fixed base plate; 26: Movable base plate;

[0039] 3: Rotating cylinder; 31: First chamber; 32: Second chamber; 33: Third chamber;

[0040] 4: Drainage component; 41: Straight segment;

[0041] 5: Leaf blade; 51: First leaf blade; 52: Second leaf blade;

[0042] 6: Mixed gas inlet;

[0043] 7: First gas outlet;

[0044] 8: Second gas outlet;

[0045] 9: Drainage catheter;

[0046] 10: Return pipe;

[0047] 11: First exhaust pipe;

[0048] 12: Support shell; 121: First support arm; 122: Second support arm;

[0049] 13: Electric motor;

[0050] 14: Gear transmission mechanism;

[0051] 15: First flange;

[0052] 16: First mechanical seal assembly;

[0053] 17: Second mechanical seal assembly;

[0054] 18: Second flange;

[0055] 19: Third mechanical seal assembly;

[0056] α: The angle between the tangent at any point on the outer wall of the first separation chamber near the gas mixture inlet and the axis of the rotating cylinder in the same plane;

[0057] β: The angle between the tangent at any point on the outer wall of the first separation chamber near the first gas outlet and the axis of the rotating cylinder in the same plane;

[0058] Fn: The component perpendicular to the direction of the rotating drum;

[0059] Fx: The component parallel to the direction of the rotating drum;

[0060] N: Resultant force;

[0061] v: speed. Detailed Implementation

[0062] To better explain and facilitate understanding of the present invention, a detailed description of the invention is provided below with reference to the accompanying drawings and specific embodiments. In this document, directional terms such as "up," "down," "left," and "right" are used interchangeably. Figure 1 The orientation is used as a reference.

[0063] This invention proposes a cascade separation device and method for mixed gases. On one hand, it provides a separation device that divides a first separation chamber into an interconnected pressurization separation chamber and an expansion separation chamber for two-stage separation of the mixed gas. Simultaneously, a second separation chamber is located at the radially distal end of the first separation chamber to further purify and separate the heavy gas components separated from the first separation chamber. The first separation chamber is equipped with blades to maintain laminar flow of the mixed gas, preventing remixing. The angle between the tangent at any point on the inner wall of the first separation chamber and its coplanar axis of rotation is less than 90 degrees, allowing the separated heavy gas components to adhere to the wall and move along the wall of the first separation chamber towards the second separation chamber. This separation device is simple in structure, compact in size, and low in energy consumption, meeting the needs of multiple fields.

[0064] On the other hand, a separation method is provided that uses the above-mentioned separation equipment and is based on four physical mechanisms: strong centrifugal force, stratified flow, and the environment in which the mixed gas at a large flow rate is in a laminar flow state and Brownian motion is suppressed. This method achieves the separation between light and heavy components, greatly improving the separation efficiency and effect of the mixed gas.

[0065] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0066] In this invention, the first gas is the lighter component gas, referring to the gas with the smaller molar mass in a mixture of two gases; the second gas is the heavier component gas, referring to the gas with the larger molar mass in a mixture of two gases. However, the first and second gases are not limited to a single gas; they can also be mixtures, such as separating four mixed gases pairwise. Therefore, the first and second gases here simply refer to the two different components obtained after separation (either a single gas or a mixture).

[0067] Meanwhile, the separation of mixed gases (i.e., the separation between different component gases in a mixed gas) cannot be completely separated as in the case of gas and solid or liquid and solid. Therefore, the separation described in this invention refers to partial separation, not complete separation of two different component gases, and current technology cannot achieve complete separation between gases.

[0068] Example 1:

[0069] Reference Figure 1 This embodiment provides a cascade separation device for mixed gases, based on the following physical properties of the mixed gases:

[0070] Centrifugal force: The net force acting on a particle undergoing uniform circular motion within its plane of motion is called centripetal force. It is a necessary condition for the particle to maintain uniform circular motion. The direction of the centripetal force is from the particle's position to the center of the circle, and its magnitude is the product of the particle's mass, the radius of the circle, and the square of the angular velocity. When a gas mixture undergoes uniform circular motion within a cavity, each gas molecule can be considered as a point mass. Gas molecules with larger molecular weights require a greater centripetal force than gas molecules with smaller molecular weights at the same position. According to the kinetic theory of gases, the centripetal force required by gas molecules within the cavity (excluding the inner wall of the cavity) is provided by the net force of the average collision force and non-contact forces (attraction or repulsion) exerted by other molecules on the molecule within the plane of circular motion. Conversely, the centripetal force required by gas molecules within the inner wall of the cavity is provided by the net force of the average collision force and non-contact forces exerted by other molecules on the molecule, as well as the force exerted by the inner wall of the cavity on the molecule within the plane of circular motion. At the same location within the cavity, molecules with larger molecular weights require a greater centripetal force than molecules with smaller molecular weights. Consequently, the net force on molecules with larger molecular weights in the plane of circular motion may be less than the centripetal force required for them to perform uniform circular motion at that point. As a result, they move from that point outwards from the circumference, within the area enclosed by the tangent to the circumference at that point and the circumference near that point. This phenomenon is called centrifugal force.

[0071] Strong centrifugal force: Strong centrifugal force of gas molecules generally refers to the significant separation, stratification, or directional movement behavior exhibited by gas molecules under the influence of centrifugal force, which is much greater than gravity or other forces, in a high-speed rotating or strong centrifugal force field. In this embodiment, it is a centrifugal acceleration greater than 2000 m / s². 2 .

[0072] Wall adhesion effect: This refers to the phenomenon where, when a fluid (gas or liquid) flows past a solid wall, the interaction between the fluid and the wall (such as viscous forces, molecular adsorption, boundary layer formation, etc.) causes the fluid to exhibit significantly different physical properties or dynamic behaviors in the near-wall region compared to the mainstream region. Essentially, this phenomenon is a localized manifestation of fluid-solid boundary interactions. It can also be understood as molecular adsorption and concentration polarization occurring near the wall; that is, solutes or particles in the fluid adsorb near the wall due to van der Waals forces, electrostatic interactions, etc., leading to localized concentration changes.

[0073] Laminar flow: Laminar flow is an ordered state of fluid motion. Its core characteristic is that fluid particles move along smooth, parallel streamlines. There is no macroscopic mixing between different flow layers. The exchange of matter or momentum is achieved only through molecular diffusion. That is, when the flow velocity is very low, the fluid flows in layers and does not mix with each other.

[0074] Turbulence is a highly disordered state of fluid motion. Its core characteristic is that fluid particles exhibit random pulsations and multi-scale vortex structures in three-dimensional space, leading to a significant increase in the efficiency of energy, momentum, and mass transfer. That is, when the flow velocity increases to a very high level, streamlines between fluids are no longer clearly distinguishable, many small vortices appear in the flow field, laminar flow is disrupted, and there is not only sliding between adjacent flow layers but also mixing. At this time, the fluid undergoes irregular motion, with velocity components perpendicular to the flow tube axis. This motion is called turbulence, also known as disturbance, disturbance, or turbulent flow.

[0075] Transitional flow: This is the intermediate state of a fluid transitioning from laminar to turbulent flow. Its core characteristic is the simultaneous existence of ordered laminar regions and local turbulent spots in the flow, and the flow stability is significantly affected by small disturbances. That is, in a laminar fluid, as the flow velocity increases, the streamlines of the fluid begin to exhibit wave-like oscillations, and the frequency and amplitude of the oscillations increase with the increase of the flow velocity.

[0076] Brownian motion refers to the random, continuous motion of tiny particles (such as pollen, dust, colloidal particles, etc.) suspended in a liquid or gas due to random collisions with surrounding fluid molecules; that is, the random thermal motion between molecules.

[0077] like Figure 2 As shown in the figure, the mechanical separation device in this embodiment includes a rotating unit and a stationary unit that are in dynamic sealing contact. The rotating unit includes a first separation chamber 1 that rotates coaxially, a second separation chamber 2 located at the radially distal end of the first separation chamber 1, and a rotating cylinder 3 that penetrates the interior of the first separation chamber 1. Inside the first separation chamber 1, there is also a guide element 4 for guiding the mixed gas to the second separation chamber 2 and several blades 5 for keeping the mixed gas in a laminar flow state. The stationary unit includes a mixed gas inlet 6 and a first gas outlet 7 that are respectively connected to both ends of the rotating cylinder 3, and a second gas outlet 8 that is connected to the second separation chamber 2. The connection between the rotating unit and the stationary unit is preferably achieved through a mechanical sealing assembly to achieve dynamic sealing contact.

[0078] The first separation cavity 1 has a rotating structure, that is, a rotating cavity, where the angle between the tangent at any point on its inner wall and the axis of rotation in the same plane is less than 90 degrees. Preferably, the first separation cavity 1 is designed as a spherical structure with the same shape for both the inner and outer walls. Figure 6 As shown, the arrow indicates the direction of the mixed gas flow from the inlet to the outlet, the dashed line is the tangent at any point on the outer wall of the first separation chamber 1, α is the angle between the tangent at any point on the outer wall of the first separation chamber 1 near the mixed gas inlet 6 and the axis of the rotating drum in the same plane, and β is the angle between the tangent at any point on the outer wall of the first separation chamber 1 near the first gas outlet 7 and the axis of the rotating drum in the same plane.

[0079] The second separation chamber 2 is an annular structure perpendicular to the axis of the rotating cylinder 3 and fitted on the outer wall at the maximum radius of the first separation chamber 1. The second separation chamber 2 and the first separation chamber 1 are connected to each other to allow gas to pass through. Preferably, several round holes can be opened on the inner wall at the junction of the first separation chamber 1 and the second separation chamber 2.

[0080] Meanwhile, the radial distance from the inner wall of the second separation chamber 2 on the side away from the first separation chamber 1 to the outer wall of the first separation chamber 1 gradually increases along the direction from the mixed gas inlet 6 to the first gas outlet 7.

[0081] The second separation chamber 2 is fitted at the maximum radius of the first separation chamber 1. The wall surface on the side away from the first separation chamber forms an angle with the axis of the rotating cylinder 3 in the direction of the first gas outlet 7. The space inside the second separation chamber 2 gradually increases from the mixed gas inlet 6 end to the first gas outlet 7 end. Preferably, the radial centerline of the rotating cylinder 3 is located in the 1 / 4-2 / 3 region of the axial direction of the second separation chamber 2.

[0082] Meanwhile, within the second separation chamber 2, several drainage conduits 9 are provided in the radially distal region near the first gas outlet 7, communicating with the second gas outlet 8. Conversely, several return pipes 10 are provided in the radially proximal region near the mixed gas inlet 6, allowing the mixed gas in the second separation chamber 2 to flow back to the inlet of the first separation chamber 1. In this embodiment, both the drainage conduits 9 and the return pipes 10 are evenly distributed circumferentially along the inner wall of the first separation chamber 1. The drainage conduits 9 extend along the inner wall of the first separation chamber 1 to the region near the rotating cylinder 3, communicating with the second gas outlet 8. The return pipes 10 extend along the inner wall of the first separation chamber 1 to the region near the rotating cylinder 3, communicating with the inlet of the first separation chamber 1. This arrangement ensures that the drainage conduits 9 and the first separation chamber 1, as well as the return pipes 10 and the first separation chamber 1, are in a relatively static state. That is, the relative flow velocity of the gas in the drainage conduits 9 and the return pipes 10 relative to the first separation chamber 1 is the same as the flow velocity at the mixed gas inlet 6, maintaining laminar flow of a large volume of gas and avoiding secondary mixing of gas caused by turbulence. Meanwhile, the area with the largest diameter of the second separation chamber 2 (i.e., the area furthest from the rotating drum 3) is the region with the greatest centrifugal force in this separation equipment, and its vibration will also be relatively large. If the rotating drainage pipe 9 is directly connected to the second gas outlet 8 near this position, the sealing will be difficult, and leakage is likely to occur due to excessive vibration. Therefore, the drainage pipe 9 is placed close to the inner wall of the first separation chamber 1, and extended radially along the first separation chamber 1 to the area near the rotating drum 3 before being connected to the second gas outlet 8 through a mechanical seal component. This results in a better sealing effect, lower difficulty, and lower cost.

[0083] In this embodiment, the second separation chamber 2 is set in this inclined form, which allows the mixed gas entering it to be better separated again. That is, the mixed gas entering the second separation chamber 2 is subject to centrifugal force. The second gas is subjected to a larger centrifugal force and will move further away from the first gas, accumulating in large quantities near the drainage conduit 9 and being discharged through the drainage conduit 9. As the amount of second gas accumulates, the remaining gas is squeezed by the second gas and will accumulate towards the return pipe 10, and then flow back to the first separation chamber 1 through the return pipe 10. Through this structural improvement, the purity of the separated second gas can be greatly improved.

[0084] Based on this, to further improve the separation efficiency and purity, and to avoid repeated mixing of the separated second and first gases within the second separation chamber 2, a multi-layered structure with numerous micropores is provided circumferentially within the second separation chamber 2. This ensures that the gas entering the second separation chamber 2 is in an environment where Brownian motion is suppressed. It should be noted that this layered structure is designed to minimize the remixing of separated gases; it cannot completely prevent gas mixing. This layered structure is radially positioned between the drainage conduit 9 and the return conduit 10. Each layered structure is divided into several circumferential sections for easy individual maintenance and replacement later. Specifically, as... Figure 8 As shown, the second separation chamber 2 includes an L-shaped inclined cover plate 21, a proximal small plate 22, a distal small plate 23, and a distal end plate 24. The proximal small plate 22 is welded and fixed to the side of the first separation chamber 1 near the mixed gas inlet 6, and the distal small plate 23 is welded and fixed to the side of the first separation chamber 1 near the first gas outlet 7. The vertical plate of the L-shaped inclined cover plate 21 is detachably connected to the proximal small plate 22 with bolts, and the horizontal plate of the L-shaped inclined cover plate 21, at the end away from its vertical plate, is detachably connected to the distal small plate 23 with bolts through the distal end plate 24. The L-shaped inclined cover plate 21, the proximal small plate 22, the distal small plate 23, and the distal end plate 24, together with the outer wall of the first separation chamber 1, form the outer shell of the second separation chamber 2.

[0085] Inside the second separation chamber 2, a ring-shaped fixed base plate 25 and a movable base plate 26 are arranged from the outside in. Both the fixed base plate 25 and the movable base plate 26 are divided into several blocks circumferentially. Each fixed base plate 25 is fixedly connected to an L-shaped inclined cover plate 21 and forms a frame inwards (the direction closest to the axis of the rotating cylinder 3 is considered inwards). Several movable base plates 26 are detachably mounted on this frame structure. Preferably, mounting grooves are provided on the sidewalls of the frame structure where each movable base plate 26 contacts the frame structure, allowing the movable base plate 26 to slide within these grooves for easy installation and removal of the fixed base plate 25. The fixed base plate 25 and the movable base plate 26 then enclose an installation space for mounting a layered structural component capable of suppressing Brownian motion. This layered structural component is stacked and fills the installation space. Preferably, the layered structural component is high-temperature resistant asbestos cloth with micropores between 1μm and 10μm in size, and the number of layers is set to 5-20, filling the installation space as completely as possible. Both the fixed substrate 25 and the movable substrate 26 have channels for gas flow. In this embodiment, circular holes with a diameter of 1mm-2mm are used, but it is not limited to this. As long as it can provide sufficient support and constraint for the layered structure and ensure gas flow, it is acceptable.

[0086] Meanwhile, bolts are used to detachably connect the L-shaped inclined cover plate 21 and the near end plate 22, as well as the far end plate 24 and the far end plate 23 and the L-shaped inclined cover plate 21. This is to facilitate the removal of the L-shaped inclined cover plate 21 and its internal substrate (including the fixed substrate 25 and the movable substrate 26) by horizontal pulling, and then to disassemble the fixed substrate 25 separately to replace the layered structural components in the installation space. This structure of the second separation cavity 2 makes installation and maintenance very convenient.

[0087] The guide 4 is a plate-shaped piece that is vertical and runs through the rotating cylinder 3. The guide 4 is located in the middle of the second separation chamber 2 in the axial direction, preferably located at 1 / 2-2 / 3 of the distance from the proximal small plate 22 to the distal small plate 23. The guide 4 extends from the rotating cylinder 3 vertically to the wall of the first separation chamber 1. A channel for gas to pass through is left near the wall of the first separation chamber 1 so as to divide the first separation chamber (1) into a pressurized separation chamber (101) and an expansion separation chamber (102) that are connected to each other.

[0088] At the same time, the draining component 4 also divides the rotating cylinder 3 into a first cavity 31 and a second cavity 32 that are not connected. The rotating cylinder 3 is also provided with a third cavity 33 that is not connected to the second cavity 32. It is located at the end of the second cavity 32 away from the draining component 4. That is, the rotating cylinder 3 is divided into a first cavity 31, a second cavity 32 and a third cavity 33 that are not connected to each other from the air inlet end to the air outlet end. The end of the first cavity 31 furthest from the second cavity 32 is connected to the mixed gas inlet 6 via a first flange 15 with an inlet pipe. The first flange 15 and the mixed gas inlet 6 are in dynamic sealing contact, and their dynamic sealing connection is achieved through a first mechanical seal assembly 16. The peripheral wall of the first cavity 31 has several through holes communicating with the pressurization separation chamber 101, forming a channel connecting the first separation chamber 1 to the mixed gas inlet 6. These through holes are preferably evenly distributed and have a diameter between 15mm and 20mm. The end of the second cavity 32 furthest from the first cavity 31 is connected to a first outlet pipe 11 communicating with the first gas outlet 7. The first outlet pipe 11 extends through the third cavity 33, and its end extending out of the third cavity 33 is in dynamic sealing contact with the first gas outlet 7. Their dynamic sealing connection is achieved through a second mechanical seal assembly 17. The peripheral wall of the second cavity 32 is connected to the expansion separation chamber 101. Several through holes 02 are connected to form a channel connecting the first separation chamber 1 to the first gas outlet 7. The through holes are preferably set to the same size as the through holes on the peripheral wall of the first chamber 31. The end of the third chamber 33 away from the second chamber 32 is connected to the second gas outlet 8 through a second flange 18 with an outlet pipe. The second flange 18 and the second gas outlet 8 are in dynamic sealing contact. The dynamic sealing connection between the two is connected by a third mechanical seal assembly 19. The drainage conduit 9 penetrates the peripheral wall of the third chamber 33 and communicates with its interior so that the drainage conduit 9 is connected to the second gas outlet 8 (wherein the third chamber 33 and the second flange 18 are not connected to the first outlet pipe 11, the inner diameter of the outlet pipe on the second flange 18 is larger than the outer diameter of the first outlet pipe 11, and a channel for gas to pass through is formed between the second flange 18 and the first outlet pipe 11. The gas entering the third chamber 33 flows into the second gas outlet 8 through this channel).

[0089] like Figure 3 As shown, the blades 5 in the first separation chamber 1 are axially perpendicular to the rotating cylinder 3 and are positioned on the inner wall of the first separation chamber 1, penetrating the pressurization separation chamber 101 and the expansion separation chamber 102. This forms multiple laminar flow channels between adjacent blades 5 (the numerous and elongated flow channels allow the gas in each channel to be in a laminar flow state). In other words, the blades 5 simultaneously divide the pressurization separation chamber 101 and the expansion separation chamber 102 into multiple elongated small chambers, causing the mixed gas entering the pressurization separation chamber 101 and the expansion separation chamber 102 to be guided by the blades 5 and dispersed into each small chamber, thus achieving a laminar flow state. This method of separating the fluid (i.e., the mixed gas) by setting a large number of blades 5, thereby reducing flow turbulence, is based on the following principle:

[0090] The flow pattern is defined by the Reynolds number:

[0091] Re=ud / v,

[0092] Where: Re is the Reynolds number; u is the magnitude of the gas velocity vector; d is the equivalent diameter; v is the kinematic viscosity.

[0093] The gas velocity includes the circumferential velocity of rotation and the flow velocity in the direction of flow. Since the gas is pushed to rotate at a constant speed by the blades 5, after a certain time, the gas and the blades 5 have the same rotational speed, and their relative velocity is 0, that is, they are relatively stationary. Therefore, when calculating the Reynolds number, only the flow velocity needs to be considered, and the flow velocity is determined by the inlet velocity, which can be set to 3~5 m / s.

[0094] The blades are divided into 5 square flow channels. The formula for calculating the equivalent diameter of the square flow channel is:

[0095] d = xy / 2(x + y),

[0096] Where: x is the length of the square flow channel; y is the width of the square flow channel.

[0097] Since the length of the square flow channel is constant, as the number of blades increases, its width y continuously decreases. When y is much smaller than x, x + y approximates x, and the formula for the equivalent diameter can be simplified to:

[0098] d = xy / 2(x+y) ≈ xy / 2 x = y / 2

[0099] Therefore, the more blades there are, the smaller the equivalent diameter.

[0100] Dynamic viscosity v is related to the temperature and pressure of the gas and can be considered a constant under normal operating conditions.

[0101] Therefore, by increasing the number of blades 5, the gas Reynolds number can be controlled. When Re is less than 2300, it is generally considered to be a weakly disturbed laminar flow state, which can reduce mixing during the flow process. That is, by setting blades 5 in the first separation chamber 1, when the gas flow rate entering the separation device is constant, the more blades 5 are set, the smaller the flow rate of each flow channel, and the larger the aspect ratio of the fan-shaped flow channel, the closer the flow is to the laminar flow state, the less mixing occurs between the fluids, and the better the separation effect is achieved.

[0102] Meanwhile, a channel for the mixed gas to flow is provided between the radial distal end of the blade 5 and the second separation chamber 2. The radial proximal end of the blade 5 is connected to the rotating cylinder 3. To avoid the blades 5 near the rotating cylinder 3 being too dense and affecting the gas flow, the blades 5 can be set in various sizes, with different sizes of blades 5 arranged alternately, and the distance between the radial proximal end of the blades 5 and the rotating cylinder 3 is different for different sizes. As for the specific number of blades 5 and the quantity of each type of blade 5, it needs to be determined according to the Reynolds number. Only one size of blade 5 can be set, or two or more sizes of blades 5 can be set. Those skilled in the art can calculate this using existing formulas, and it will not be elaborated here.

[0103] In this embodiment, two types of blades 5 are provided, namely a first blade 51 and a second blade 52. A portion of the radial distal end of the two types of blades 5 (i.e., the end closest to the second separation chamber 2) is cut off to form a notch, so that there is a certain distance between the blade 5 and the second separation chamber 2 to allow gas to pass through. The remaining arc-shaped sidewall of the blade 5 after removing the cut-off portion is fixedly connected to the inner wall of the first separation chamber 1. There is no gap between the first blade 51 and the rotating cylinder 3, and there is a gap of 250mm-300mm between the second blade 52 and the rotating cylinder 3 to ensure the gas flow rate in the area near the rotating cylinder 3. The first blade 51 and the second blade 52 are alternately arranged around the circumference of the rotating cylinder 3, and the included angle between adjacent blades 5 is 15°.

[0104] like Figure 4 and Figure 5 As shown, in this embodiment, a support housing 12 is fitted around the rotating unit, and the stationary unit is fixedly connected to the support housing 12. Specifically, a first support arm 121 and a second support arm 122 are respectively provided at both ends of the support housing 12. The first support arm 121 is fixedly connected to the mixed gas inlet 6, and the second support arm 122 is fixedly connected to the first gas outlet 7 and the second gas outlet 8. At the same time, a motor 13 is provided at one end of the support housing 12 near the mixed gas inlet 6. The motor 13 is connected to the rotating drum 3 through a gear transmission mechanism 14 to drive the rotating drum 3 to rotate.

[0105] Compared with the prior art, the mechanical separation equipment shown in this embodiment has the following significant advantages:

[0106] First, it has a small volume; for the same processing capacity (e.g., 10,000 m³ / h), a 2m³ unit is much smaller. 3 The spherical separation equipment can replace approximately 8m 3 The industrial small-scale gas separation equipment, for example, the separation equipment shown in this embodiment is a sphere with a diameter of 1.4m, and with auxiliary equipment (motor 13 and support housing 12, etc.), the total volume is 2m³. 3 A certain combined skid-mounted natural gas desulfurization and purification equipment has a processing capacity of 35,000 m³. 3 / day, diameter 0.75m, height 2.7m, converted to 10000m 3 The volume of / h is approximately 8m³ 3 .

[0107] Secondly, it is low in cost. The separation equipment shown in this embodiment is a purely machined part, with low production cost. During use, it only needs to be driven by an electric motor. Compared with separation technologies such as chemical separation, it does not require chemical agents or other additional costs, resulting in lower operating costs.

[0108] Third, it has high reliability. Compared with technologies such as molecular sieves that require frequent replacement of separation components, the separation equipment shown in this embodiment is a purely mechanical device, containing only a few rotating parts such as a rotating drum. According to current technology, it can operate stably for more than 40,000 hours.

[0109] Fourth, it has a wide range of applications. The separation equipment shown in this embodiment can disperse gas pressure through its spherical structure design and can withstand 23 atmospheres of pressure in natural gas desulfurization processes. Therefore, it can be applied in high-temperature, high-pressure, and corrosive environments. For example, in coal chemical (coal-to-methane) production processes, it can directly concentrate, purify, and separate components such as methane, hydrogen, carbon monoxide, carbon dioxide, aromatics, and heavy hydrocarbons at high temperatures; remove sulfides from sulfur-containing biogas; directly remove methane from the air in coal mining tunnels, which is beneficial to mine safety; separate different components such as heavy hydrocarbons, carbon dioxide, and hydrogen sulfide in natural gas; separate sulfides, nitrogen oxides, and carbon dioxide in power plant tail gas; and achieve the separation of hydrogen, methane, and aromatics in the coking process.

[0110] Based on the aforementioned mechanical separation equipment, this embodiment also provides a method for separating mixed gases, specifically including the following steps:

[0111] S1: The mixed gas enters the pressurized separation chamber 101 in the first separation chamber 1 through the mixed gas inlet 6 and the rotating drum 3. Based on the centrifugal force and the environment of laminar flow and wall adhesion effect, the first gas and the second gas are separated into layers, and the primary separation is completed.

[0112] S2: The mixed gas that has completed the primary separation moves towards the second separation chamber 2 under the guidance of the guide 4;

[0113] The second gas flows along the inner wall of the pressurized separation chamber 101 and enters the second separation chamber 2 in large quantities. The first gas is displaced by the second gas and cannot flow along the inner wall of the pressurized separation chamber 101. Only a small amount of the first gas enters the second separation chamber 2.

[0114] The remaining mixed gas, containing a large amount of the first gas and a small amount of the second gas, enters the expansion separation chamber 102 in the first separation chamber 1;

[0115] S3: The mixed gas entering the expansion separation chamber 102 further achieves stratified flow based on the action of centrifugal force. Part of the second gas flows against the wall and enters the second separation chamber 2. The concentration of the first gas in the expansion separation chamber 102 is further increased, completing the secondary separation of the first gas. The separated first gas flows forward and is discharged through the first gas outlet 7.

[0116] S4: The mixed gas that enters the second separation chamber 2 through steps S2 and S3 completes the secondary separation of the second gas under the action of centrifugal force and the suppression of Brownian motion. A large amount of the second gas accumulates at the radial distal end of the second separation chamber 2, while the remaining gas is squeezed to the radial proximal region of the second separation chamber 2 by the second gas. The separated second gas is then discharged through the second gas outlet 8, and the remaining gas returns to the pressurized separation chamber 101 for re-circulation and separation.

[0117] The aforementioned small and large quantities of the first gas / second gas refer only to the relative values ​​of the first gas quantity and the second gas quantity in the current mixed gas (e.g., in the pressurization separation chamber 101 / in the expansion separation chamber 102 / in the second separation chamber 2).

[0118] Each step is discussed in detail below:

[0119] Regarding step S1:

[0120] In this embodiment, the motor 13 is connected to the rotating drum 3 via a gear transmission mechanism 14, driving the entire rotating unit to rotate. The mixed gas enters the first chamber 31 of the rotating drum 3 through the mixed gas inlet 6. Blocked by the guide member 4, it enters the pressurized separation chamber 101 in the first separation chamber 1 through a circular hole on the peripheral wall of the first chamber 31. Based on the strong centrifugal force and the laminar flow and wall-adhering effect, the first and second gases achieve stratified flow, completing the primary separation. In this embodiment, the centrifugal acceleration is greater than 2000 m / s². 2 This is a state of strong centrifugal force.

[0121] At this point, the molecules in the gas mixture can be considered to some extent as small spheres of different masses. Since the angular velocity and radius of rotation are constant during coaxial rotation at the same position, the centrifugal force can be calculated using the following formula:

[0122] F=ma=mw 2 R,

[0123] Where: F is the centrifugal force; m is the mass of a gas molecule; a is the centrifugal acceleration; w is the angular velocity of rotation; and R is the distance of the molecule from the center of the rotation axis.

[0124] It is known that gas molecules with larger molecular weights (larger mass) will experience greater centrifugal force, thus moving away from the center of rotation (i.e., the axis of the rotating drum 3). This causes the mixed gas to form stratification of different molecular weights along the radial direction of the rotating drum 3 within the first separation chamber 1. The components with larger molecular weights are further away from the rotating drum 3. In other words, the second gas moves away from the rotating drum 3 compared to the first gas, so that the mixed gas entering the pressurized separation chamber 101 undergoes primary separation. Furthermore, since the pressurized separation chamber 101 is equipped with blades 5 that keep the mixed gas in a laminar flow state, the gases in the initial separation state are not easily remixed, thus maintaining the stratified flow state as much as possible and improving the efficiency of gas separation.

[0125] Meanwhile, based on the shape where the angle between the tangent at any point on the inner wall of the first separation chamber 1 and its axis of rotation in the same plane is less than 90 degrees, the gas in the pressurized separation chamber 101 will exhibit a wall-attaching effect. That is, when the second gas moves to the inner wall of the pressurized separation chamber 101, due to the supporting force of the inner wall, the centrifugal force and the supporting force reach equilibrium, and the molecules adhere tightly to the inner wall surface. Other molecules are pressed layer by layer onto the inner wall surface. Macroscopically, this manifests as a higher concentration of gas molecules with larger molecular weights (i.e., the second gas) at a certain position close to the inner wall surface. Conversely, gas molecules with smaller molecular weights (i.e., the first gas) accumulate near the rotating cylinder 3. Therefore, the overall gas concentration is higher at a distance close to the inner wall surface of the pressurized separation chamber 101, and the gases of different components are arranged in layers. It should be noted that if the gas flow rate is high and the flow is turbulent, this wall-attaching effect will be broken, resulting in the mixing of gases with different molecular weights. Therefore, a large number of blades 5 are installed in the pressurization separation chamber 101 to separate the fluid, reduce the turbulence of the flow, and ensure that the large flow rate of mixed gas entering the pressurization separation chamber 101 remains in a weakly turbulent laminar flow state. This also ensures that the wall-attaching effect is not broken. Therefore, the laminar flow and wall-attaching effect environment here is created by the installation of a large number of blades 5 and the fact that the angle between the tangent at any point on the inner wall of the first separation chamber 1 and its axis of rotation in the same plane is less than 90 degrees.

[0126] Regarding step S2:

[0127] In this embodiment, the mixed gas that has completed primary separation moves towards the second separation chamber 2 under the guidance of the guide element 4. For example... Figure 7As shown, a gas molecule in the pressurized separation chamber 101 moves upward with the flow direction and centrifugal force, gradually reaching the wall-attached state. At this time, the gas molecule is subjected to a resultant force N from other gas molecules and the wall support force. Among them, the component Fn of the resultant force N perpendicular to the direction of the rotating cylinder 3 provides the centripetal force to maintain the circular motion, and the component Fx parallel to the direction of the rotating cylinder 3 is perpendicular to the velocity v, causing the gas molecule to move along the wall-attached direction along the dotted line. Since the second gas (gas molecules with larger molecular weight) is subjected to a larger centrifugal force, under the pressure of the gas continuously introduced into the mixed gas inlet 6, the second gas flows along the inner wall of the pressurized separation chamber 101 and enters the second separation chamber 2 in large quantities. The first gas is displaced by the second gas and cannot flow along the inner wall of the pressurized separation chamber 101. Only a small amount of the first gas enters the second separation chamber 2, and the remaining mixed gas with a large amount of the first gas and a small amount of the second gas enters the expansion separation chamber 102 in the first separation chamber 1.

[0128] Regarding step S3:

[0129] In this embodiment, the mixed gas entering the expansion separation chamber 102 further achieves stratified flow due to the strong centrifugal force. The separation of the mixed gas in the expansion separation chamber 102 is similar to that in the pressurization separation chamber 101, and will not be described in detail here. Finally, a portion of the second gas in the expansion separation chamber 102 flows in the opposite direction along the wall into the second separation chamber 2, further increasing the concentration of the first gas in the expansion separation chamber 102, thereby completing the secondary separation of the first gas. The separated first gas flows forward and is discharged through the first gas outlet 7.

[0130] Meanwhile, when a large amount of mixed gas enters the expansion separation chamber 102 through the pressurization separation chamber 101, during the expansion separation chamber 102, part of the energy gained by the gas through the pressurization separation process in the pressurization separation chamber 101 will be transferred to the blades 5 in the expansion separation chamber 102 to do work, thus reducing the input of some external power.

[0131] Regarding step S4:

[0132] In this embodiment, the mixed gas that enters the second separation chamber 2 through steps S2 and S3 completes the secondary separation of the second gas based on the strong centrifugal force and the Brownian motion suppression environment.

[0133] Because the second separation chamber 2 is equipped with a multilayered layered structure with several micropores that can suppress Brownian motion, the first gas and the second gas entering the second separation chamber 2 are not easily remixed. Also, because the centrifugal force on the first gas is less than that on the second gas, and based on the shape of the second separation chamber 2 where the internal space gradually increases along the axial direction, a large amount of the second gas accumulates at the radially distal end of the second separation chamber 2, while the remaining gas is squeezed to the radially proximal region of the second separation chamber 2 by the second gas. Finally, under the pressure difference effect of the continuous filling of mixed gas, the separated second gas is discharged from the second gas outlet 8 through the drainage conduit 9, and the remaining gas returns to the pressurized separation chamber 101 through the return pipe 10 for re-circulation and separation.

[0134] In the process of separating the mixed gas, the separation of the first gas is mainly concentrated in the pressurization separation chamber 101 and the expansion separation chamber 102. The combined operation of the pressurization separation chamber 101 and the expansion separation chamber 102 can achieve cascade separation of the first gas, resulting in a higher concentration of the discharged first gas. Similarly, the separation of the second gas is mainly concentrated in the pressurization separation chamber 101 and the second separation chamber 2. The combined operation of the pressurization separation chamber 101 and the second separation chamber 2 can achieve cascade separation of the second gas, resulting in a higher concentration of the discharged second gas.

[0135] Meanwhile, the cascade separation device proposed in this embodiment can be used alone or in series with multiple stages. That is, another identical device can be connected at the first gas outlet 7 and / or the second gas outlet 8 for further separation. The subsequent separation process is the same as the above process, and will not be described again here.

[0136] The following describes a cascade separation device and method for mixed gases, based on this embodiment, using air as an example. The workflow of this mechanical separation device is briefly described. As is well known, gases with similar molecular weights are more difficult to separate. Air consists of two main components: oxygen (concentration approximately 21%, molecular weight 32.00 g / mol) and nitrogen (concentration approximately 78%, molecular weight 28.02 g / mol). Their molecular weights are very close, with a mass ratio of only 1.14, making separation difficult. Oxygen is defined as the second gas, and nitrogen as the first gas.

[0137] First, the rotating unit (including the pressurization separation chamber 101, the expansion separation chamber 102, the second separation chamber 2, the rotating drum 3, the guide element 4, and the blades 5) is driven to rotate by the motor 13. Air enters the first chamber 31 of the rotating drum 3 from the mixed gas inlet 6. Due to the obstruction of the guide element 4, the air enters the pressurization separation chamber 101 through the circular hole on the peripheral wall of the rotating drum 3. Under strong centrifugal force, oxygen adheres to the inner wall of the pressurization separation chamber 101 and accumulates. Nitrogen is squeezed by oxygen and gathers closer to the rotating drum 3. The air achieves primary separation in the pressurization separation chamber 101.

[0138] Then, when the gas flows to the position furthest from the rotating drum 3, the oxygen concentration is highest at the wall. It enters the second separation chamber 2 through the channel between the pressurized separation chamber 101 and the second separation chamber 2 for further separation. Under the environment where Brownian motion is suppressed, the oxygen concentration is further increased. Specifically, the oxygen and nitrogen entering the second separation chamber 2 will not be remixed due to the effect of the layered structure with several micropores that can suppress Brownian motion. Under the action of strong centrifugal force, the oxygen is subjected to a larger centrifugal force and gathers towards the radially distal end of the second separation chamber 2. It is discharged into the second gas outlet 8 through the drainage conduit 9 and the third chamber 33 of the rotating drum 3. The nitrogen is subjected to a smaller centrifugal force and gathers towards the radially proximal end of the second separation chamber 2. It returns to the pressurized separation chamber 101 through the return pipe 10 for re-separation.

[0139] Under the influence of gas pressure difference, the nitrogen-rich air in the pressurization separation chamber 101 enters the expansion separation chamber 102. During the expansion process of the air in the pressurization separation chamber 101, a portion of the energy gained by the gas through the pressurization separation process is transferred to the blades 5 in the expansion separation chamber 102 to do work, which can reduce the input of external power. The small amount of oxygen entering the expansion separation chamber 102 will still be affected by strong centrifugal force, so it will continue to accumulate against the wall in the expansion separation chamber 102 and flow counterclockwise towards the second separation chamber 2. It enters the second separation chamber 2 through the channel between the expansion separation chamber 102 and the second separation chamber 2. The remaining nitrogen-rich air is discharged through the second chamber 32 at the other end of the rotating drum 3 and the first gas outlet 11 into the first gas outlet 7, thereby realizing the separation of oxygen and nitrogen in the air.

[0140] Finally, the oxygen concentration after separation can be monitored by installing an oxygen concentration detector at the second gas outlet 8. The separation equipment shown in this embodiment ensures a centrifugal acceleration of at least 2000 m / s². 2Under these conditions, the separated oxygen concentration can reach at least 50%-60%, and even up to 80%. Existing centrifugal separators, when used to separate oxygen from air, typically only achieve around 30%-40%, requiring multiple cascaded stages to reach approximately 50%. This results in low separation efficiency, high energy consumption, and complex structure. Therefore, this separation equipment demonstrates significant separation performance. If used to separate gases such as methane from raw natural gas, which have significantly different molecular weights compared to other gases in the mixture, the separation effect will be even better.

[0141] The following section describes a cascade separation device and method for mixed gases proposed in this embodiment, taking a mixed gas of hydrogen (molecular weight 2 g / mol), methane (molecular weight 16 g / mol), nitrogen (molecular weight 28.02 g / mol), and carbon dioxide (molecular weight 44 g / mol) as an example, to briefly describe the process of connecting multiple stages of this device in series to obtain four different gases with relatively high concentrations.

[0142] This separation requires three identical units of this equipment: one as the main unit, and the other two connected to the first gas outlet 7 and the second gas outlet 8 of the main unit (i.e., the first and second secondary units). By appropriately adjusting the speed of motor 13 (the appropriate speed can be calculated by those skilled in the art based on the formula for centrifugal force, so it will not be elaborated further), the lighter component of the mixed gas (i.e., hydrogen and methane) is discharged from the first gas outlet 7 of the main unit and enters the first and second secondary units. The heavier component of the mixed gas (i.e., nitrogen and carbon dioxide) is discharged from the second gas outlet 8 of the main unit and enters the second and second secondary units. Then, the hydrogen and methane in the first and second secondary units are separated, and the nitrogen and carbon dioxide in the second and second secondary units are separated, resulting in four different gases with relatively high concentrations. The specific separation process in these three units is similar to the process of separating oxygen and nitrogen from air described above, so it will not be elaborated further. Those skilled in the art can select the number of units connected in series according to actual needs to obtain various desired single / mixed gases.

[0143] Example 2:

[0144] Reference Figure 9 As shown, this embodiment provides a cascade separation device for mixed gases. It differs from the separation device provided in Embodiment 1 only in the structure of the inlet element 4. All other parts are the same as in Embodiment 1 and will not be described again here.

[0145] The thickness of the guide member 4 shown in this embodiment gradually decreases from the center (near the axis of the rotating cylinder 3) to the edge (near the inner wall of the first separation chamber 1), and its two opposite sides facing the pressurization separation chamber 101 and the expansion separation chamber 102 are concave. That is, the guide member 4 is a rotating structure with the axis of rotation of the rotating cylinder 3 as the axis of rotation, and its rotational cross section is a concave arc shape with the thickness gradually decreasing from the axis of rotation to the distal end. At the same time, a straight segment 41 is provided in the central region of the guide member 4 (near the axis of rotation of the rotating cylinder 3) to transition from the maximum thickness to the surrounding area, avoiding sharp corners at the center of rotation, so that the overall outline of the guide member 4 is smooth. The guide member 4 with this structure can effectively improve the separation efficiency, reduce energy loss, and ensure the stability of the flow field.

[0146] Firstly, regarding improving separation efficiency, when gas moves along a curved surface, the change in curvature generates a centrifugal force gradient. Components with different densities are more significantly affected by the difference in centrifugal force. Simultaneously, the curvature-induced secondary flow can increase the radial migration of the gas mixture, promoting component stratification. In contrast, for a planar surface, after gas impacts the plane perpendicularly, momentum is mainly converted into pressure energy, resulting in a weaker inertial separation effect. The secondary flow on the plane is also weaker, and separation primarily relies on the initial centrifugal force. Secondly, regarding reducing energy loss, the streamlined curved surface can guide the gas to smoothly change direction, reducing flow separation and kinetic energy loss. In contrast, for a planar surface, when gas impacts the plane perpendicularly, stagnation zones and backflow vortices are easily formed, and energy is wasted through turbulent dissipation. Furthermore, the arc-shaped guide 4 helps to keep the large flow rate of gas in the first separation chamber 1 in a laminar flow state. Finally, regarding ensuring the stability of the flow field, the curved surface can guide the particles to move along the tangential direction, reducing direct accumulation on the wall surface, and the centrifugal force is evenly distributed along the curved surface, avoiding local stress concentration and extending the equipment life. In contrast, for the flat surface, particles are prone to adhesion after impacting the flat surface perpendicularly, leading to blockage and potentially requiring frequent cleaning. Furthermore, the impact force is concentrated at the collision center, which may cause structural fatigue or wear.

[0147] The interior of the drainage component 4 shown in this embodiment can be a solid structure or a cavity structure, as long as both sides of its exterior (i.e., the side facing the pressurization separation chamber 101 and the side facing the expansion separation chamber 102) are smoothly transitioned arc-shaped structures.

[0148] In the description of this invention, it should be understood that 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 indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0149] 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 or an electrical connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0150] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is 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," or "beneath" the second feature can mean that the first feature is 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.

[0151] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present 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.

[0152] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A cascade separation device for mixed gases, characterized in that: Includes rotating units and stationary units; The rotating unit includes a first separation chamber (1) that rotates coaxially, a second separation chamber (2) disposed at the radially distal end of the first separation chamber (1), and a rotating cylinder (3) that penetrates the interior of the first separation chamber (1). The first separation chamber (1) has a rotating structure. The angle between the tangent at any point on its inner wall and the axis of rotation in the same plane is less than 90 degrees. The first separation chamber (1) is provided with a guide (4) to guide the mixed gas to the second separation chamber (2) and several blades (5) to make the mixed gas in a laminar flow state. The guide (4) divides the first separation chamber (1) into a pressurized separation chamber (101) and an expansion separation chamber (102) that are connected to each other, and divides the rotating cylinder (3) into a first chamber (31) and a second chamber (32) that are not connected to each other. The stationary unit includes a mixed gas inlet (6) and a first gas outlet (7) that are respectively connected to both ends of the rotating drum (3), and a second gas outlet (8) that is connected to the second separation chamber (2); The inside of the rotating drum (3) forms a first separation chamber (1) that connects the mixed gas inlet (6) and the first gas outlet (7).

2. The cascade separation device for mixed gases as described in claim 1, characterized in that: The second separation chamber (2) is an annular structure perpendicular to the axis of the rotating drum (3) and sleeved on the outer wall of the first separation chamber (1). The radial distance from the inner wall of the second separation chamber (2) away from the outer wall of the first separation chamber (1) gradually increases along the direction from the mixed gas inlet (6) to the first gas outlet (7). The second separation chamber (2) has several drainage pipes (9) in the radially distal region near the first gas outlet (7) that are connected to the second gas outlet (8), and several return pipes (10) in the radially proximal region near the mixed gas inlet (6) that allow the mixed gas in the second separation chamber (2) to flow back to the inlet of the first separation chamber (1).

3. A cascade separation device for mixed gases as described in claim 2, characterized in that: The rotating drum (3) is also provided with a third cavity (33) that is not connected to the second cavity (32). The third cavity (33) is located at the end of the second cavity (32) that is far away from the drain (4). The end of the first chamber (31) away from the second chamber (32) is connected to the mixed gas inlet (6), and the peripheral wall of the first chamber (31) is provided with several through holes that are connected to the pressurization separation chamber (101); The second cavity (32) is connected to a first gas outlet pipe (11) that communicates with the first gas outlet (7) at one end away from the first cavity (31), and the first gas outlet pipe (11) is installed through the third cavity (33). The peripheral wall of the second cavity (32) is provided with several through holes that communicate with the expansion separation cavity (102). The end of the third cavity (33) away from the second cavity (32) is connected to the second gas outlet (8), and the drainage conduit (9) passes through the periphery of the third cavity (33) and is connected to its interior.

4. A cascade separation device for mixed gases as described in claim 1, characterized in that: The second separation chamber (2) is provided with a multi-layered structure with several micropores along the circumferential direction to suppress Brownian motion, so as to slow down the remixing of the separated gases.

5. A cascade separation device for mixed gases as described in claim 1, characterized in that: The blade (5) is vertically mounted on the inner wall of the first separation chamber (1) along the axial direction and passes through the pressurization separation chamber (101) and the expansion separation chamber (102) to form multiple gas laminar flow channels between adjacent blades (5). A channel for mixed gas to flow is left between the radial far end of the blade (5) and the second separation chamber (2).

6. A cascade separation device for mixed gases as described in claim 5, characterized in that: The blades (5) are of different sizes, and blades (5) of different sizes are alternately arranged, and the distance from the radial proximal end of the blades (5) of different sizes to the rotating cylinder (3) is different.

7. A cascade separation device for mixed gases as described in claim 1, characterized in that: The draining member (4) is a plate-shaped member that is vertically arranged and penetrates through the rotating drum (3) to separate the first separation chamber (1) and the rotating drum (3) into a pressurization separation chamber (101) and an expansion separation chamber (102) and the first chamber (31) and the second chamber (32) respectively, and the draining member (4) is located in the middle of the axial direction of the second separation chamber (2).

8. A cascade separation device for mixed gases as described in claim 7, characterized in that: The thickness of the draining component (4) gradually decreases from the center to the edge. Its two opposite sides facing the pressurization separation chamber (101) and the expansion separation chamber (102) are concave. The central area of ​​the draining component (4) is provided with a straight section (41) for the transition from the maximum thickness to the surrounding area.

9. A cascade separation device for mixed gases as described in any one of claims 1-8, characterized in that: The rotating unit is fitted with a support shell (12), and the stationary unit is fixedly connected to the support shell (12). The rotating unit and the stationary unit are in contact through a dynamic seal. A motor (13) is provided at one end of the support housing (12) near the gas mixture inlet (6). The motor (13) is connected to the rotating drum (3) through a gear transmission mechanism (14) to drive the rotating unit, including the rotating drum (3), to rotate.

10. A method for separating mixed gases, characterized in that: The separation of a mixed gas using the separation apparatus as described in any one of claims 1-9, wherein the first gas is a light component gas and the second gas is a heavy component gas, specifically includes the following steps: S1: The mixed gas enters the pressurized separation chamber (101) in the first separation chamber (1) through the mixed gas inlet (6) and the rotating drum (3). Based on the centrifugal force and the environment of laminar flow and wall adhesion effect, the first gas and the second gas are separated and the primary separation is completed. S2: The mixed gas after primary separation moves towards the second separation chamber (2) under the guidance of the guide (4); The second gas flows along the inner wall of the pressurized separation chamber (101) and enters the second separation chamber (2) in large quantities. The first gas is displaced by the second gas and cannot flow along the inner wall of the pressurized separation chamber (101). Only a small amount of the first gas enters the second separation chamber (2). The remaining mixture of a large amount of the first gas and a small amount of the second gas enters the expansion separation chamber (102) in the first separation chamber (1); S3: The mixed gas entering the expansion separation chamber (102) further achieves stratified flow based on the centrifugal force. Part of the second gas flows against the wall and enters the second separation chamber (2). The concentration of the first gas in the expansion separation chamber (102) is further increased, completing the secondary separation of the first gas. The separated first gas flows forward and is discharged through the first gas outlet (7). S4: The mixed gas that enters the second separation chamber (2) through steps S2 and S3 completes the secondary separation of the second gas based on the action of centrifugal force and the Brownian motion suppression environment. A large amount of the second gas accumulates at the radial distal end of the second separation chamber (2), while the remaining gas is squeezed to the radial proximal region of the second separation chamber (2) by the second gas. The separated second gas is then discharged through the second gas outlet (8), and the remaining gas returns to the pressurized separation chamber (101) for re-circulation separation.

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