A static mixer for oil-water emulsification

Abstract

The invention discloses a static mixer for oil-water emulsification, and relates to the technical field of oil-water emulsification. The static mixer comprises an oil-water mixing tube, a dosing tube is fixed on one side of the top of the oil-water mixing tube close to a feed port, support rings are symmetrically fixed inside the oil-water mixing tube, and a DNA-imitating double-helix channel is fixed between two groups of support rings. The invention fixes the DNA-imitating double-helix channel between the two groups of support rings inside the oil-water mixing tube, and fixes shark-shield-scale-imitating ribs distributed in an array on the inner wall of the DNA-imitating double-helix channel, utilizes a unique bionic principle, simulates the efficient mixing phenomenon in nature, and realizes efficient and uniform mixing of fluids in a steady-state environment. The invention can not only guide the fluid to generate micro-vortices, but also promote full contact and collision between oil droplets and water droplets, and significantly improve the emulsification efficiency and stability. No external power source is required, and efficient mixing can be achieved by relying on the energy of the fluid itself. The overall structure of the device is compact and easy to install, and the device is suitable for emulsification processes of various scales.

Description

Technical Field

[0001] The invention relates to the technical field of oil-water emulsification, in particular to a static mixer for oil-water emulsification. Background Art

[0002] Oil-water emulsification refers to the phenomenon that a liquid (usually oil) is evenly dispersed in another immiscible liquid (usually water) in the form of extremely small droplets. In this process, surfactants (also called emulsifiers) are usually added to reduce the interfacial tension between the two liquids so that the oil droplets can be stably dispersed in water. In the petroleum industry, oil-water emulsification is used in the extraction and transportation of crude oil. Through emulsification, the viscosity of crude oil can be reduced, and the fluidity and leveling of crude oil can be improved, thereby improving extraction efficiency and transportation capacity. As an important equipment, the design and performance of static mixers directly affect the emulsification effect and product quality.

[0003] In recent years, with the rapid development of bionics, people have begun to look for inspiration from nature to optimize the design of static mixers. Sharks, as top predators in the ocean, have a unique shield scale structure covering their body surface. The ribs on these shield scales have complex groove morphology, which not only has excellent drag reduction performance, but also can cause strong vortexes and shear forces in the fluid, thereby enhancing the mixing effect of the fluid. Inspired by this, the groove morphology of shark shield scale ribs is applied to the design of static mixers, which is expected to significantly improve the efficiency of oil-water emulsification mixing.

[0004] At the same time, as a landmark discovery in life sciences, the DNA double helix structure, with its unique spatial configuration and stability, also provides new ideas for the design of static mixers. The two chains in the DNA double helix structure are entangled with each other to form two helical structures. This structure is not only stable and compact, but also can achieve a stable phase in which the disturbance of the two-phase materials reaches equilibrium at the molecular level. Introducing this feature of the DNA double helix structure into the design of the static mixer can construct a channel structure with efficient mixing and transmission performance, further improving the efficiency and stability of oil-water emulsification.

[0005] Traditional static mixers usually use channels and ribs of various shapes to enhance the mixing effect between fluids. Not only are the structural design complex and the manufacturing cost high, but there are often problems such as low mixing efficiency, high energy consumption and insufficient stability of the emulsion. Therefore, the present invention proposes a static mixer for oil-water emulsification to solve the problems existing in the prior art. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to propose a static mixer for oil-water emulsification, which solves the problems that the existing static mixer for oil-water emulsification is not only complex in structure design and high in manufacturing cost, but also often has low mixing efficiency, high energy consumption and insufficient emulsion stability.

[0007] In order to achieve the purpose of the present invention, the present invention is implemented through the following technical scheme: a static mixer for oil-water emulsification, including an oil-water mixing tube, a dosing tube is fixed on the side of the top of the oil-water mixing tube close to the feed port, support rings are symmetrically fixed inside the oil-water mixing tube, a DNA-imitating double helix channel is fixed between two groups of the support rings, and the inner side wall of the DNA-imitating double helix channel is fixed with shark shield scale-imitating ribs distributed in an array.

[0008] A further improvement is that the DNA-simulated double helix channel comprises a first spiral rib and a second spiral rib, wherein the first spiral rib and the second spiral rib are arranged in reverse parallel and are wound around the same central axis.

[0009] A further improvement is that first flange connection rings are fixed to both ends of the oil-water mixing tube, and a first annular sealing groove is provided on a side of the first flange connection ring away from the oil-water mixing tube.

[0010] A further improvement is that a second flange connection ring is fixed to the top end of the dosing pipe, and a second annular sealing groove is provided on a side of the second flange connection ring away from the dosing pipe.

[0011] A further improvement is that arc grooves are symmetrically provided on the shark shield scale-imitation ribs, and two groups of arc grooves are separated on the shark shield scale-imitation ribs to form three groups of spires.

[0012] A further improvement is that the ratio of the height of the middle peak in the three groups of peaks to the height of the arc-shaped groove is 12:7, and the ratio of the height of the middle peak to the width of the shark shield scale rib is 1:1.

[0013] The beneficial effects of the present invention are as follows: the present invention fixes a DNA-like double helix channel between two groups of support rings on the inner side of the oil-water mixing tube, and fixes array-distributed shark shield scale ribs on the inner wall of the DNA-like double helix channel, and utilizes unique bionic principles to simulate the efficient mixing phenomenon in nature, thereby achieving efficient and uniform mixing of fluids in a steady-state environment. It can not only guide the fluid to generate micro-vortices, but also promote full contact and collision between oil droplets and water droplets, significantly improving the emulsification efficiency and stability, and does not require an external power source, but can achieve efficient mixing by relying on the energy of the fluid itself, which is energy-saving and environmentally friendly. In addition, the overall structure of the device is compact and easy to install, and is suitable for emulsification processes of various scales. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a cross-sectional view of the present invention;

[0015] Figure 2 It is a schematic diagram of the internal structure of the oil-water mixing tube of the present invention;

[0016] Figure 3 This is a schematic diagram of the three-dimensional structure of the shark shield scale-imitation ribs of the present invention;

[0017] Figure 4 Schematic diagram of the structure and size of the shark shield scale-like ribs in an embodiment of the present invention;

[0018] Figure 5 This is a simulation diagram of a single body model of a shark shield scale rib in an embodiment of the present invention;

[0019] Figure 6 It is a model simulation diagram of the DNA double helix channel in the embodiment of the present invention.

[0020] Among them: 1. oil-water mixing tube; 2. dosing tube; 3. support ring; 4. DNA-like double helix channel; 5. shark shield scale-like ribs; 6. first flange connecting ring; 7. first annular sealing groove; 8. second flange connecting ring; 9. second annular sealing groove; 401. first spiral rib; 402. second spiral rib; 501. arc groove; 502. spire. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] See also Figure 1 , Figure 2 , Figure 3The present embodiment provides a static mixer for oil-water emulsification, comprising an oil-water mixing tube 1 for oil-water fluid to pass through and a dosing tube 2 welded and fixed to the top of the oil-water mixing tube 1, the dosing tube 2 being used to add emulsifier into the oil-water mixing tube 1, in the present embodiment, the left end of the oil-water mixing tube 1 is a feed inlet, the right end is a discharge outlet, the dosing tube 2 is located on the left side of the top of the oil-water mixing tube 1, the oil-water mixing tube 1 is fixed with support rings 3 symmetrically distributed on the left and right by bolts, the support ring 3 is designed in a circular ring shape, the outer wall of which is in contact with the inner wall of the oil-water mixing tube 1, a DNA-imitating double helix channel 4 is fixed between the two groups of support rings 3, the inner wall of the DNA-imitating double helix channel 4 is fixed with shark shield scale ribs 5, and the shark shield scale ribs 5 are fixed to the inner wall of the shark shield scale ribs 5. The inner wall of the DNA-simulating double helix channel 4 is evenly distributed in an array. Through the combination of the DNA-simulating double helix channel 4 and the shark shield scale-simulating ribs 5, the fluid undergoes multiple divisions and recombination in the oil-water mixing tube 1, which is conducive to more complete contact and mixing between oil and water. In the laminar state, the fluid will go through the process of division-position movement-re-merge, and a shearing effect is generated in this process, which is conducive to further dispersion and mixing of oil droplets and water droplets. In the turbulent state, in addition to the above process, the fluid will also generate violent vortices in the cross-sectional direction. This vortex has a strong shear force and can more effectively disperse the oil droplets and water droplets into smaller particles, thereby improving the stability of the emulsion.

[0023] The DNA-simulating double helix channel 4 includes a first spiral rib 401 and a second spiral rib 402. The first spiral rib 401 and the second spiral rib 402 are arranged in reverse parallel and are intertwined around the same central axis to simulate the structural characteristics of the DNA double helix through two spiral mechanisms. This structure is not only stable and compact, but also can produce strong rotation and shearing effects when the fluid passes through, further promoting the emulsification and mixing of oil and water.

[0024] A first flange connection ring 6 is welded and fixed at both ends of the oil-water mixing tube 1. The oil-water mixing tube 1 is installed by flange connection. A first annular sealing groove 7 is provided on the side of the first flange connection ring 6 away from the oil-water mixing tube 1. When the oil-water mixing tube 1 is installed, a sealing ring is placed in the first annular sealing groove 7 to improve the sealing performance during flange connection.

[0025] A second flange connection ring 8 is fixed on the top of the dosing pipe 2, and the dosing pipe 2 is installed and docked at the discharge port of the emulsifier supply equipment by flange connection. A second annular sealing groove 9 is provided on the side of the second flange connection ring 8 away from the dosing pipe 2 to improve the sealing performance during flange connection.

[0026] The shark shield scale-like ribs 5 are symmetrically provided with arc-shaped concave arc grooves 501. Two groups of arc grooves 501 are separated on the shark shield scale-like ribs 5 to form three groups of sharp spires 502. The circular grooves 501 and the spires 502 cooperate with each other to achieve the best drag reduction effect.

[0027] like Figure 4 As shown, the height of the middle peak 502 among the three groups of peaks 502 is 60 mm, the height of the arc groove 501 is 35 mm, and the width of the shark shield scale rib 5 is 60 mm. The best fluid dynamics performance is achieved through precise size design.

[0028] The shark shield scale ribs 5 and DNA double helix channel 4 were simulated by FIUENT software. Figure 5 This is a simulation diagram of a single model of the shark shield scale rib 5 in this embodiment. Figure 6 It is a model simulation diagram of the DNA double helix channel 4 in this embodiment.

[0029] When the static mixer for oil-water emulsification is actually used, the left end of the oil-water mixing tube 1 is first used as a feed port and connected to the oil-water supply end, and the right end of the oil-water mixing tube 1 is used as a discharge port and connected to the emulsion collection end. Oil and water enter from the feed port at the left end of the oil-water mixing tube 1, and at the same time, an emulsifier is added to the inside of the oil-water mixing tube 1 through the dosing tube 2. Subsequently, the fluid composed of oil, water and emulsifier passes through the DNA-simulated double helix channel 4 between the two groups of support rings 3, and under the action of the shark shield scale ribs 5, a strong rotation and shearing effect is generated to achieve static mixing. Finally, the uniformly mixed emulsion is discharged from the drain port at the right end of the oil-water mixing tube 1.

[0030] In this embodiment, the multiphase flow model Volume of Fluid model (VOF model) is used in the FIUENT software simulation, which is suitable for tracking the interface position of two or more immiscible fluids and meets the requirements. The conservation equation of the fluid volume fraction changing with time is:

[0031]

[0032] in, α is the fluid volume fraction, in %, ρ is the fluid density in kg / m³, t is the time in s, ∇· is the divergence operator, which is a unitless quantity, u is the fluid velocity in m / s, and ∂ represents the partial derivative;

[0033] At the same time, the turbulence model in this embodiment adopts Realizable K- ε model, which is based on the standard K- ε By adding terms related to rotation and curvature to the equation, K and ε The transport equation is as follows:

[0034]

[0035] in, Gk is the generation term of turbulent kinetic energy k caused by the mean velocity gradient, G b is the generation term of turbulent kinetic energy k caused by buoyancy, G M is the compressibility correction term, G K is the source term of the k equation, x j represents the variable related to j;

[0036] To quantitatively analyze the homogenization effect, the coefficient of variation ( C o V ) and Sauter mean diameter (d 32 ) respectively represent the uniformity of dispersion distribution and the particle size of dispersion, and the equations are as follows:

[0037]

[0038]

[0039] in, σ is the standard deviation, N is the number of data points, c i is the volume fraction of water phase in the ith region, is the average volume fraction of water phase on the cross section, in %, d i is the diameter of the droplet, in m, n i The particle size is d i is the number of droplets, and c is the volume fraction of the water phase.

[0040] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A static mixer for oil-water emulsification, comprising an oil-water mixing tube (1), characterized in that: A dosing tube (2) is fixed on one side of the top of the oil-water mixing tube (1) close to the feed port, a support ring (3) is symmetrically fixed inside the oil-water mixing tube (1), a DNA-simulating double helix channel (4) is fixed between two groups of the support rings (3), and shark shield scale-simulating ribs (5) distributed in an array are fixed to the inner side wall of the DNA-simulating double helix channel (4), the DNA-simulating double helix channel (4) comprises a first helical rib (401) and a second helical rib (402), the first helical rib (401) and the second helical rib (402) are arranged in reverse parallel and around the same central axis The two ends of the oil-water mixing pipe (1) are both fixed with a first flange connection ring (6), and a first annular sealing groove (7) is provided on the side of the first flange connection ring (6) away from the oil-water mixing pipe (1). A second flange connection ring (8) is fixed on the top of the dosing pipe (2), and a second annular sealing groove (9) is provided on the side of the second flange connection ring (8) away from the dosing pipe (2). The shark shield scale ribs (5) are symmetrically provided with arc grooves (501), and two groups of arc grooves (501) are separated on the shark shield scale ribs (5) to form three groups of spires (502).

2. The static mixer for oil-water emulsification according to claim 1, characterized in that: The ratio of the height of the apex (502) located in the middle of the three groups of apex (502) to the height of the arc-shaped groove (501) is 12:7, and the ratio of the height of the apex (502) located in the middle to the width of the shark shield scale rib (5) is 1:1.

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