A turbulent mixer structure for oil-water emulsification

Abstract

The invention discloses a turbulent mixer structure for oil-water emulsification, comprising an oil-water mixing tube and a spiral strip, wherein the spiral strip is fixedly arranged in the oil-water mixing tube, a dorsal fin spiral rib is fixedly arranged around one side of the spiral strip, the dorsal fin spiral rib is provided with three split spirals, a first rib edge is connected to the inner side of the spiral strip, a second rib edge is connected to the outer side of the spiral strip, the first rib edge and the second rib edge are both triangular, an arc-shaped turbulent protrusion is matched and fixedly arranged between the spiral strip and the dorsal fin spiral rib, and a honeycomb grid is fixedly arranged between the first rib edge and the second rib edge and the spiral strip; the invention forms a multi-stage vortex excitation zone through the split spiral structure of the dorsal fin spiral rib and the step-by-step decreasing design of the spiral curvature, induces the superposition of vortices of different scales, accelerates the oil-water mixing process, and divides the flow field and regulates the boundary layer flow through the synergistic effect of the hexagonal periodic topological units of the honeycomb grid and the micron-level groove array on the surface, enhances the microscopic shear effect, and improves the droplet breakup efficiency and mixing uniformity.

Description

Technical Field

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

[0002] In the oil-water emulsification process, the performance of the static mixer directly determines the uniformity and stability of the emulsion. Traditional mixers mostly use fixed blades, spiral channels or bionic rib structures, such as DNA double helix or shark shield scale ribs, to achieve mixing by inducing vortexes. However, this type of design has limitations in the regulation of complex flow fields: a single spiral structure is prone to form a stable laminar flow, resulting in a decrease in mixing efficiency; the geometric parameters of the bionic ribs are fixed and difficult to adapt to multiple working conditions; in addition, the existing structure has insufficient ability to segment and reorganize the microscopic flow field, which limits the degree of refinement of the emulsion droplets.

[0003] Recent studies have shown that fractal geometry can enhance flow field disturbances through multi-scale features, while honeycomb topology can significantly improve the secondary segmentation effect of the fluid due to its high specific surface area and periodic unit characteristics. However, how to organically combine the fractal spiral with the honeycomb grid to construct an efficient mixer with both macroscopic disturbances and microscopic shearing remains a technical difficulty. In response to the above problems, the present invention proposes an innovative structure in which the fractal spiral dorsal fin ribs are coupled with the honeycomb grid topology to solve the technical defects of insufficient turbulence intensity and poor adaptability of traditional mixers. Therefore, the present invention proposes a turbulent mixer structure for oil-water emulsification to solve the problems existing in the prior art. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to propose a turbulent mixer structure for oil-water emulsification, which forms a multi-stage vortex excitation zone through the type-type spiral structure of the dorsal fin spiral ribs and the step-by-step decreasing design of the spiral curvature, thereby inducing the superposition of vortices of different scales, significantly improving the turbulence intensity, and accelerating the oil-water mixing process. Through the synergistic effect of the hexagonal periodic topological units of the honeycomb grid and the surface micron-level groove array, the flow field is divided and the boundary layer flow is regulated, the microscopic shear effect is enhanced, and the droplet breakup efficiency and mixing uniformity are improved.

[0005] To achieve the purpose of the present invention, the present invention is implemented through the following technical scheme: a turbulent mixer structure for oil-water emulsification, including an oil-water mixing tube and a spiral strip, the spiral strip is fixedly provided in the oil-water mixing tube, the inner side of the spiral strip is connected to a first rib, the outer side of the spiral strip is connected to a second rib, the first rib and the second rib are both triangular, a dorsal fin spiral rib is fixedly provided around one side of the spiral strip, the dorsal fin spiral rib is provided with three parting spirals, the dorsal fin spiral rib extends from the tube wall to the center of the tube in a parting spiral, and its spiral curvature decreases step by step along the axial direction, an arc-shaped turbulent protrusion is fixedly provided between the spiral strip and the dorsal fin spiral rib, and a honeycomb grid is fixedly provided between the first rib and the second rib and the spiral strip.

[0006] A further improvement is that the cross-section of the dorsal fin spiral rib is triangular, and the ratio of the height of the arc-shaped spoiler protrusion to the width of the dorsal fin spiral rib is 1:2.

[0007] A further improvement is that the honeycomb grid is formed by coupling the first rib edge and the second rib edge along the spiral track with the starting point of the dorsal fin spiral rib to form a hexagonal periodic topological unit.

[0008] Further improvements are: the ratio of the side length of the hexagonal unit of the honeycomb grid to the pitch of the dorsal fin spiral rib is 1:5, the ratio of the wall thickness of the hexagonal unit of the honeycomb grid to the side length is 1:3, and the surface of the honeycomb grid is provided with a micron-level groove array.

[0009] A further improvement is that the spiral directions of the dorsal fin spiral ribs are arranged alternately in reverse, and the phase difference between adjacent dorsal fin spiral ribs is 120°.

[0010] A further improvement is that the direction of the honeycomb grid forms an angle of 30°-60° with the mainstream direction of the fluid.

[0011] A further improvement is that a tail bracket is fixedly provided at one end of the dorsal fin spiral rib, and the tail bracket is triangular.

[0012] The beneficial effects of the present invention are as follows: the present invention forms a multi-level vortex excitation zone through the type spiral structure of the dorsal fin spiral ribs and the step-by-step decreasing design of the spiral curvature, induces the superposition of vortices of different scales, significantly improves the turbulence intensity, and accelerates the oil-water mixing process. Through the synergistic effect of the hexagonal periodic topological units of the honeycomb grid and the surface micron-level groove array, the flow field is divided and the boundary layer flow is regulated, the microscopic shear effect is enhanced, and the droplet breakup efficiency and mixing uniformity are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is an overall front cross-sectional view of the present invention;

[0014] Figure 2A three-dimensional schematic diagram of the spiral ribs of the dorsal fin of the present invention;

[0015] Figure 3 A three-dimensional schematic diagram of the spiral strip grid of the present invention;

[0016] Figure 4 A microscopic three-dimensional schematic diagram of a honeycomb grid of the present invention;

[0017] Figure 5 This is a simulation diagram of the dorsal fin spiral rib model of the present invention;

[0018] Figure 6 It is a simulation streamline diagram of the dorsal fin spiral rib model of the present invention.

[0019] Among them: 1. Oil-water mixing tube; 2. Spiral strip; 3. First rib edge; 4. Second rib edge; 5. Honeycomb grid; 6. Dorsal fin spiral rib; 7. Arc-shaped spoiler protrusion; 8. Tail bracket. DETAILED DESCRIPTION

[0020] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0021] according to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, the present embodiment provides a turbulent mixer structure for oil-water emulsification, including an oil-water mixing tube 1 and a spiral strip 2, wherein the spiral strip 2 is fixedly provided inside the oil-water mixing tube 1, and a dorsal fin spiral rib 6 is fixedly provided around one side of the spiral strip 2, and the dorsal fin spiral rib 6 is provided with three parting spirals, and the dorsal fin spiral rib 6 extends from the tube wall to the center of the tube in a parting spiral, and its spiral curvature decreases step by step along the axial direction to form a multi-stage vortex excitation zone, and the spiral curvature decreases in three stages along the axial direction: the curvature radius of the inlet section R1=25mm (corresponding to a spiral angle of 60°), and the transition section R2=52mm (spiral angle of 45°). The curvature graded design makes the fluid experience strong swirl, transitional swirl and weak swirl in sequence, forming a multi-scale vortex superposition. By utilizing the geometric characteristics of the dorsal fin spiral ribs 6, the fluid experiences a continuous change in spiral radius when passing through, inducing the superposition of vortices of different scales, and greatly improving the turbulence intensity. A first rib edge 3 is connected to the inner side of the spiral strip 2, and a second rib edge 4 is connected to the outer side of the spiral strip 2. The first rib edge 3 and the second type of edge are both triangular. An arc-shaped spoiler protrusion 7 is fixed between the spiral strip 2 and the dorsal fin spiral rib 6, and a honeycomb grid 5 is fixed between the first rib edge 3 and the second rib edge 4 and the spiral strip 2.

[0022] The cross-section of the dorsal fin spiral rib 6 is triangular (base width 25mm, height 1mm), the ratio of the height of the arc-shaped spoiler protrusion 7 to the width of the dorsal fin spiral rib 6 is 1:2, and the arc is also in the shape of the dorsal fin and is 8mm. The multi-stage release of flow field energy is achieved through the graded design of spiral curvature, combined with alternating reverse arrangement and phase difference layout, breaking the flow field symmetry and significantly improving the macroscopic disturbance efficiency.

[0023] The honeycomb grid 5 is formed by coupling the first rib 3 and the second rib 4 along the trajectory of the spiral strip 2 with the starting point of the dorsal fin spiral rib 6 to form a hexagonal periodic topological unit. The ratio of the side length of the hexagonal unit of the honeycomb grid 5 to the pitch of the dorsal fin spiral rib 6 is 1:5, and the ratio of the wall thickness of the hexagonal unit of the honeycomb grid 5 to the side length is 1:3. A micron-scale groove array is provided on the surface of the honeycomb grid 5. The periodic topology of the honeycomb grid is coupled with the spiral trajectory to form a flow field segmentation network in a three-dimensional space. The microscopic groove array is used to regulate the boundary layer flow through the surface microstructure to enhance the microscopic shear and mixing uniformity. The honeycomb grid is used to strengthen the microscopic droplet breakup. The honeycomb grid and the dorsal fin spiral rib 6 are used to form a multi-scale turbulence synergistic effect through spatial phase matching.

[0024] The spiral directions of the dorsal fin spiral ribs 6 are alternately arranged in reverse, the phase difference between adjacent dorsal fin spiral ribs 6 is 120°, and the direction of the honeycomb grid 5 forms an angle of 30°-60° with the mainstream direction of the fluid.

[0025] A tail bracket 8 is fixedly provided at one end of the dorsal fin spiral rib 6, and the tail bracket 8 is triangular.

[0026] It constructs a multi-scale flow field synergistic system: in the lateral dimension, the isotropic shear substrate of the honeycomb structure divides the fluid into hexagonal micro-units, and its symmetrical topological characteristics ensure uniform distribution of shear stress; in the axial dimension, the fractal spiral guide vanes induce Dean vortex pairs with a spacing of 0.5-2mm (Reynolds number 50-300), and form cascading vortices at submicron to millimeter scales through self-similar structures; at the microscopic level, the periodic velocity gradient of the spiral edge and the honeycomb wall work synergistically to trigger the Kelvin-Helmholtz instability of the oil-water interface, and cooperate with the three-dimensional spatial redistribution mechanism of the fluid to reduce the Sauter average diameter value of the dispersed phase to 62% of that of the traditional structure. With the help of the spatiotemporal coupling characteristics of the spiral fractal, dynamic matching of millisecond-level microscopic shear and second-level macroscopic mixing is achieved, and ultimately a 2.3-fold increase in the mixing energy efficiency index is achieved in the Reynolds number range of 50-800, which is particularly suitable for efficient emulsification of oil-water systems with a viscosity ratio of >10:1.

[0027] Fluid testing was performed using FIUENT software simulation. The multiphase flow model Volume of Fluid model (VOF model) was used in the FIUENT software simulation. It is suitable for tracking the interface position of two or more incompatible fluids and meets the requirements. In order to analyze the transverse and longitudinal vortices, some dimensionless numbers were introduced. The secondary flow can be described by the average absolute value of the vorticity on the normal section, as shown in the equation:

[0028] in, A is the cross-sectional area, subscript y represents the normal direction of the cross section, is the vorticity.

[0029] Using dimensionless numbers Se To evaluate the strength of the secondary flow, the formula is as follows

[0030]

[0031] in, Se As a dimensionless parameter, it represents the ratio of the inertial force induced by the secondary flow to the viscous force, is the fluid viscosity, is the fluid density, Secondary flow characteristic velocity (represents the velocity characteristics of the fluid in the secondary flow direction), Characteristic length (some characteristic dimension or length associated with a flow). Often used to quantify the enhancement of secondary flows.

[0032] Swirl number ( S ) is a dimensionless number that can more accurately and comprehensively reflect the characteristics of swirl intensity. The swirl number is usually expressed by the following equation

[0033]

[0034] in, is the axial velocity, is the tangential velocity, is the pipe radius, is the pipe diameter.

[0035] The enhanced heat transfer performance of the enhanced heat transfer tube is evaluated using the Performance Evaluation Criteria (PEC), which is defined as follows:

[0036]

[0037] In the formula, Nu 0 and f 0are the Nusselt number and friction coefficient of the smooth circular tube, respectively.

[0038] The turbulent mixer structure for oil-water emulsification uses the spiral strips set in the oil-water mixing tube and the dorsal fin spiral ribs surrounding it, and uses its split spiral structure and the characteristics of spiral curvature decreasing step by step, so that the fluid undergoes vortex superposition of different scales during the flow process, forming a multi-level vortex excitation zone to enhance the turbulence intensity; at the same time, the triangular ribs and arc-shaped turbulent protrusions on both sides of the spiral strips further guide the fluid to produce a shear effect. The honeycomb grid is composed of hexagonal periodic units. The micron-level groove array on the surface divides the flow field and regulates the boundary layer flow. Combined with the spatial phase matching with the dorsal fin spiral ribs, the microscopic droplet breakage and mixing uniformity are improved through the multi-scale turbulent synergistic effect. In addition, the alternating reverse arrangement of the dorsal fin spiral ribs and the angle design between the honeycomb grid and the mainstream direction break the symmetry of the flow field, realize the multi-level release of flow field energy and the significant improvement of macroscopic disturbance efficiency, and finally optimize the oil-water mixing effect.

[0039] 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 turbulent mixer structure for oil-water emulsification, characterized in that: The invention comprises an oil-water mixing tube (1) and a spiral strip (2), wherein the spiral strip (2) is fixedly provided inside the oil-water mixing tube (1), a first rib (3) is connected to the inner side of the spiral strip (2), a second rib (4) is connected to the outer side of the spiral strip (2), the first rib (3) and the second rib are both triangular, a dorsal fin spiral rib (6) is fixedly provided around one side of the spiral strip (2), the dorsal fin spiral rib (6) is provided with three split spirals, and the dorsal fin spiral rib (6) is formed from the tube wall. The spiral extends toward the center of the tube in a fractal spiral, and the spiral curvature decreases step by step along the axial direction. An arc-shaped spoiler protrusion (7) is fixedly provided between the spiral strip (2) and the dorsal fin spiral rib (6). A honeycomb grid (5) is fixedly provided between the first rib edge (3) and the second rib edge (4) and the spiral strip (2). The honeycomb grid (5) is formed by coupling the first rib edge (3) and the second rib edge (4) along the trajectory of the spiral strip (2) with the starting point of the dorsal fin spiral rib (6), forming a hexagonal periodic topological unit.

2. The turbulent mixer structure for oil-water emulsification according to claim 1, characterized in that: The cross section of the dorsal fin spiral rib (6) is quasi-triangular, and the ratio of the height of the arc-shaped spoiler protrusion (7) to the width of the dorsal fin spiral rib (6) is 1:

2.

3. The turbulent mixer structure for oil-water emulsification according to claim 1, characterized in that: The ratio of the side length of the hexagonal unit of the honeycomb grid (5) to the pitch of the dorsal fin spiral rib (6) is 1:5, the ratio of the wall thickness of the hexagonal unit of the honeycomb grid (5) to the side length is 1:3, and a micrometer-level groove array is provided on the surface of the honeycomb grid (5).

4. The turbulent mixer structure for oil-water emulsification according to claim 1, characterized in that: The spiral directions of the dorsal fin spiral ribs (6) are arranged alternately in opposite directions, and the phase difference between adjacent dorsal fin spiral ribs (6) is 120°.

5. The turbulent mixer structure for oil-water emulsification according to claim 1, characterized in that: The direction of the honeycomb grid (5) forms an angle of 30°-60° with the mainstream direction of the fluid.

6. The turbulent mixer structure for oil-water emulsification according to claim 1, characterized in that: A tail bracket (8) is fixedly provided at one end of the dorsal fin spiral rib (6), and the tail bracket (8) is triangular in shape.

Images