A biomimetic snail shell spiral static mixer for oil-water emulsification

Abstract

This invention belongs to the field of oil-water emulsification and crude oil transportation technology, and specifically relates to a biomimetic snail shell spiral static mixer for oil-water emulsification. It includes an oil-water mixing pipe body, with an inlet straight pipe and an outlet straight pipe respectively connected to both ends of the body. The end of the inlet straight pipe is the oil-water mixing pipe inlet, and an emulsion inlet is provided on the outside of the inlet straight pipe. The end of the outlet straight pipe is the oil-water mixing pipe outlet. The inner cavity of the inlet straight pipe also has a starfish-inspired turbulence structure. By introducing biomimetic turbulence elements in the inlet region, strong swirling flow and primary shearing can be generated before the fluid enters the spiral flow channel, promoting more complete contact and breakup of the oil and water phases. Combined with the natural swirling characteristics of the snail shell flow channel, it can further improve oil-water mixing efficiency and emulsification effect, reduce energy consumption, and adapt to the needs of complex crude oil transportation and recovery conditions.

Description

Technical Field

[0001] This invention belongs to the field of oil-water emulsification and crude oil transportation technology, specifically relating to a biomimetic snail shell spiral static mixer for oil-water emulsification. Background Technology

[0002] Oil-water emulsification is the process of mixing crude oil and water mechanically, chemically, or through biomimetic structures to form a stable emulsion. Oil-water emulsification has significant engineering value and economic implications in crude oil extraction and transportation, primarily utilizing emulsification technology to improve fluidity, reduce costs, and enhance oil recovery.

[0003] Existing oil-water emulsification devices mostly employ a straight-channel structure, and enhance fluid shear and turbulence by incorporating various flow-turbulent elements (such as spiral structures, perforated plates, and mesh structures) within the channel, thereby promoting thorough oil-water mixing. However, this type of straight-channel structure suffers from problems in actual operating conditions, including a single mixing path, poor transport, sedimentation and blockage, and high flow resistance, making it difficult to achieve efficient emulsification within a limited space, especially with high-viscosity oils that require appropriate heating.

[0004] Snail-shell-like biomimetic structures possess natural helical flow channel characteristics, enabling the formation of stable swirling flow without the addition of complex external disturbance structures, enhancing shearing action without excessively increasing flow resistance. This structure also boasts a large external surface area, facilitating integrated external heating. Based on these characteristics, introducing snail-shell-like biomimetic flow channels into oil-water emulsification devices holds promise for achieving efficient mixing within a compact space. However, relying solely on the swirling characteristics of the snail shell results in limited disturbance in the inlet region, insufficient impact on initial fluid distribution and interfacial tearing, hindering the full realization of its swirling enhancement potential.

[0005] Adding certain turbulence structures to the flow channel beforehand can improve the efficiency of oil-water emulsification in the spiral channel. The starfish structure has multi-directional protrusions, and the induced vortex directions superimpose and interfere with the rotating flow of the snail shell, forming a complex rotating flow field. This enhances energy exchange and fluid mixing efficiency, ensuring that the two phases remain fully mixed throughout the flow channel, thereby improving emulsification stability. Summary of the Invention

[0006] To address the problems mentioned in the background section, this invention provides a biomimetic snail shell spiral static mixer for oil-water emulsification. This mixer features smooth conveying, low flow resistance, and a large external surface area, making it suitable for arranging heaters on the outer side for heating.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a biomimetic snail shell spiral static mixer for oil-water emulsification, comprising an oil-water mixing pipe body, wherein an inlet straight pipe and an outlet straight pipe are respectively connected and installed at both ends of the oil-water mixing pipe body, the end of the inlet straight pipe is the oil-water mixing pipe inlet, and an emulsion inlet is provided on the outside of the inlet straight pipe, the end of the outlet straight pipe is the oil-water mixing pipe outlet, and a starfish-like turbulence structure is also installed in the inner cavity of the inlet straight pipe, wherein the top of the starfish-like structure's inner surface is pointed, and the top of the starfish-like structure's outer surface is curved and connected to the inner wall of the flow channel, and the starfish-like turbulence structure is spirally arranged as a whole.

[0008] As a preferred embodiment of the biomimetic snail shell spiral static mixer for oil-water emulsification of the present invention, the ratio of the distance from the top of the inner surface of the starfish-like structure to the center point of the channel cross-section to the distance from the top of the outer surface of the starfish-like structure to the center point of the channel cross-section is 4:5.

[0009] As a preferred embodiment of the biomimetic snail shell spiral static mixer for oil-water emulsification according to the present invention, the main body of the oil-water mixing tube is configured in the shape of a biomimetic snail shell spiral.

[0010] As a preferred embodiment of the biomimetic snail shell spiral static mixer for oil-water emulsification according to the present invention, the starfish-inspired turbulence structure is located in the side channel of the inlet straight pipe near the inlet of the oil-water mixing pipe.

[0011] As a preferred embodiment of the biomimetic snail shell spiral static mixer for oil-water emulsification according to the present invention, the spiral flow channel of the main body of the oil-water mixing pipe has a circular cross-section, and its cross-sectional diameter gradually decreases from the inlet to the outlet.

[0012] As a preferred embodiment of the biomimetic snail shell spiral static mixer for oil-water emulsification according to the present invention, the length of the outlet straight pipe is not less than twice its diameter.

[0013] Compared with existing technologies, the beneficial effects of this invention are as follows: By setting a starfish-inspired turbulence structure at the front end of the snail-shell spiral channel, this invention creates a synergistic effect between the inlet multi-directional vortex and the channel spiral flow field, causing multi-scale shearing and strong turbulent mixing of the oil and water phases during flow. This structure can significantly improve emulsification uniformity and effectively prolong fluid residence time, thereby enhancing emulsification stability. Simultaneously, the biomimetic geometric flow guidance method can achieve efficient emulsification with low energy consumption. The snail-shell spiral main channel has the advantages of compact structure and anti-clogging, and its relatively high external surface area is suitable for high-viscosity crude oil systems, enabling the integration of emulsification and heating. Attached Figure Description

[0014] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0015] Figure 1 This is a schematic diagram of the external structure of the oil-water mixing pipe body of the present invention;

[0016] Figure 2 This is a schematic cross-sectional view of the main body of the oil-water mixing pipe of the present invention;

[0017] Figure 3 This is a schematic diagram of the starfish-inspired turbulence structure of the present invention;

[0018] Figure 4 For the present invention Figure 3 A schematic diagram of the cross-sectional structure in the middle;

[0019] Figure 5 This is a simulation diagram of the channel cross-section of the present invention;

[0020] Figure 6 This is a three-dimensional simulation diagram of the channel of the present invention.

[0021] In the diagram: 1. Oil-water mixing pipe inlet; 2. Emulsion inlet; 3. Starfish-inspired turbulence structure; 31. Top of the inner surface of the starfish-inspired structure; 32. Top of the outer surface of the starfish-inspired structure; 4. Main body of the oil-water mixing pipe; 5. Oil-water mixing pipe outlet; 6. Inlet straight pipe; 7. Outlet straight pipe. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1-6 As shown: A biomimetic snail shell spiral static mixer for oil-water emulsification includes an oil-water mixing pipe body 4. An inlet straight pipe 6 and an outlet straight pipe 7 are respectively connected and installed at both ends of the oil-water mixing pipe body 4. The end of the inlet straight pipe 6 is the oil-water mixing pipe inlet 1, and an emulsion inlet 2 is provided on the outside of the inlet straight pipe 6. The end of the outlet straight pipe 7 is the oil-water mixing pipe outlet 5. A starfish-inspired turbulence structure 3 is also installed in the inner cavity of the inlet straight pipe 6.

[0024] Oil and water enter through the oil-water mixing pipe inlet 1, and emulsion enters through the emulsion inlet 2. The starfish-inspired turbulence structure 3 is evenly arranged in a straight channel close to the inlet. After passing through the starfish-inspired turbulence structure 3, the oil, water and emulsion are disturbed, which can enhance the swirling and primary shearing of the oil-water mixture in the inlet area. Then, the oil-water mixture enters the biomimetic snail shell spiral static mixer, forming a continuous and stable rotating flow field in a small space. This flow pattern can significantly enhance the interfacial contact and tearing effect of the oil and water phases, thereby improving emulsification efficiency, reducing dependence on high-power mechanical shearing, and reducing energy consumption. Finally, it flows out through the outlet straight pipe 7.

[0025] In an optional embodiment, the top 31 of the inner surface of the starfish-like structure of the starfish-like turbulence structure 3 is set as a pointed tip, and the top 32 of the outer surface of the starfish-like structure of the starfish-like turbulence structure 3 is set as a curved surface and connected to the inner wall of the flow channel. The starfish-like turbulence structure 3 is arranged in a spiral shape as a whole.

[0026] In this embodiment, the spiral-shaped starfish-like turbulence structure 3 itself can give the fluid an initial rotational momentum, thereby enabling the oil-water mixture to proceed smoothly with subsequent operations.

[0027] In an optional embodiment, the ratio of the distance from the top tip 31 of the starfish-like structure inner surface of the starfish-like structure to the center point of the channel cross-section to the distance from the top tip 32 of the starfish-like structure outer surface of the starfish-like structure outer surface to the center point of the channel cross-section is 4:5.

[0028] In this embodiment: in the narrow inner region with a small proportion, the fluid velocity will increase significantly. According to the continuity equation, this will form a high-speed, high-shear region, which is very beneficial for tearing the oil phase into tiny droplets and achieving preliminary emulsification.

[0029] In an optional embodiment, the oil-water mixing pipe body 4 is configured in a biomimetic snail shell spiral shape.

[0030] In this embodiment, a continuous and stable rotating flow field is formed in a relatively small space. This flow pattern can significantly enhance the interfacial contact and tearing effect between the oil and water phases, thereby improving emulsification efficiency, reducing dependence on high-power mechanical shearing, and reducing energy consumption.

[0031] In an optional embodiment, the starfish-like turbulence structure 3 is located in the side channel of the inlet straight pipe 6 near the oil-water mixing pipe inlet 1.

[0032] In this embodiment, primary disturbances can be implemented to fully realize the cyclone mixer's efficiency enhancement potential.

[0033] In an optional embodiment, the spiral flow channel of the oil-water mixing pipe body 4 has a circular cross-section, and its cross-sectional diameter gradually decreases from the inlet to the outlet.

[0034] In this embodiment: the above settings enable the fluid inside the oil-water mixing pipe body 4 to slide smoothly and complete a series of subsequent operations.

[0035] In an optional embodiment, the length of the outlet straight pipe 7 is not less than twice its diameter.

[0036] In this embodiment, the above settings ensure a stable output of the emulsified fluid, thereby maintaining the overall functionality of the equipment.

[0037] To illustrate the technical effects of this invention, a multiphase flow (VOF) numerical simulation was performed on this embodiment using Fluent numerical simulation software, where the velocity contour plot and streamline diagram are shown below. Figure 5 and Figure 6 As shown in the velocity cloud map Figure 5 and streamline diagram Figure 6 It can be seen that under the action of the starfish-like spiral turbulence structure, the oil and water phases achieve full entrainment and interfacial stretching in the initial stage. At the same time, as the flow proceeds, under the principle of continuity equation, the gradual decrease in the cross-sectional area of ​​the channel gradually increases the overall flow velocity, further enhancing shear and kinetic energy transfer, thereby promoting oil droplet refinement, improving emulsification uniformity and system stability, while reducing overall energy consumption, and realizing an efficient and controllable oil-water emulsification process.

[0038] The basic form of the continuity equation for incompressible fluids is shown below: Where A is the cross-sectional area of ​​the channel and v is the flow velocity.

[0039] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oil-water emulsified biomimetic snail shell spiral static mixer characterized by: The oil-water mixing pipe body (4) is provided with an inlet straight pipe (6) and an outlet straight pipe (7) at both ends, respectively, the end of the inlet straight pipe (6) is an oil-water mixing pipe inlet (1), an emulsion inlet (2) is arranged on the outside of the inlet straight pipe (6), the end of the outlet straight pipe (7) is an oil-water mixing pipe outlet (5), and a sea star imitation disturbance structure (3) is further arranged in the inner cavity of the inlet straight pipe (6), the top end (31) of the inner surface of the sea star imitation structure of the sea star imitation disturbance structure (3) is provided with a sharp end, the top end (32) of the outer surface of the sea star imitation structure of the sea star imitation disturbance structure (3) is provided with a curved surface and is connected with the inner wall of the flow channel, and the sea star imitation disturbance structure (3) is provided in a spiral shape as a whole.

2. The oil-water emulsifying biomimetic snail shell spiral static mixer according to claim 1, characterized in that: The ratio of the distance between the top end (31) of the inner surface of the sea star imitation structure of the sea star imitation disturbance structure (3) to the center point of the channel cross section to the distance between the top end (32) of the outer surface of the sea star imitation structure of the sea star imitation disturbance structure (3) to the center point of the channel cross section is 4:

5.

3. The oil-water emulsifying biomimetic snail shell spiral static mixer according to claim 1, characterized in that: The oil-water mixing pipe body (4) is provided in a spiral shape of a snail shell.

4. The oil-water emulsifying biomimetic snail shell spiral static mixer according to claim 1, characterized in that: The sea star imitation disturbance structure (3) is located in the side channel of the inlet straight pipe (6) close to the oil-water mixing pipe inlet (1).

5. The oil-water emulsifying biomimetic snail shell spiral static mixer according to claim 1, characterized in that: The cross section of the spiral flow channel of the oil-water mixing pipe body (4) is circular, and the cross section diameter gradually decreases from the inlet to the outlet.

6. The biomimetic snail shell spiral static mixer for oil-water emulsification according to claim 1, characterized in that: The length of the outlet straight pipe (7) is not less than twice the diameter thereof.

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