A double-shaft coupling flow-guiding baffle stirring device for non-newtonian fluid mixing

Abstract

The application provides a double-shaft coupled flow guide type baffle stirring device for non-Newton fluid mixing, which comprises a stirring reactor kettle body, a first motor, a second motor, a first stirring shaft, a second stirring shaft, a first stirring paddle and a second stirring paddle; the stirring reactor kettle body is provided with a circular stirring groove on the upper surface; the first stirring paddle and the second stirring paddle are arranged in the stirring groove; first flow guide devices and second flow guide devices corresponding to the first stirring paddle and the second stirring paddle are fixedly arranged on the side wall of the stirring groove; the lower end of the first stirring shaft is fixedly connected with the first stirring paddle; the lower end of the second stirring shaft is fixedly connected with the second stirring paddle; the upper end of the first stirring shaft is fixedly connected with the rotating shaft of the first motor; and the upper end of the second stirring shaft is fixedly connected with the rotating shaft of the second motor. The application can make the non-Newton fluid obtain sufficient stretching and folding effects at the wall flow guide type baffle, and realize the sufficient mixing of materials.

Description

Technical Field

[0001] This invention pertains to the design and application of stirred reactors, and particularly relates to a biaxially coupled guide baffle stirring device for mixing non-Newtonian fluids. Background Technology

[0002] In industrial production and laboratory applications, many fluids, such as slurries, sols, and polymer solutions, exhibit non-Newtonian properties. Efficient mixing of these non-Newtonian fluids is of great significance in fields such as chemical synthesis, bioengineering, and food processing.

[0003] In the field of stirred reactor design, the mixing process of non-Newtonian fluids is a complex challenge due to their shear sensitivity and typically high viscosity. Traditional stirring systems include baffle-type stirring devices and baffle-less stirring devices. Baffle-type stirring devices use four baffles radially arranged around the sidewall of the stirring tank 11. These four baffles are evenly distributed radially on the sidewall of the stirring tank. When facing non-Newtonian fluids, the baffles will block the non-Newtonian fluids, easily forming a flow dead zone behind the baffles. This easily creates a mixing isolation zone, resulting in problems such as a single flow pattern, low mixing efficiency, and poor shear effect during stirring. Baffle-less stirring devices tend to form swirling flow, making it difficult to fully control the fluid flow pattern transformation and limiting the fluid mixing efficiency. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides a biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids, so as to improve the flow pattern transformation and shear efficiency of non-Newtonian fluids during stirring, and improve the efficiency and uniformity of non-Newtonian fluid mixing, comprising:

[0005] The reactor comprises a stirred tank body, a first motor, a second motor, a first stirring shaft, a second stirring shaft, a first stirring paddle, and a second stirring paddle. A circular stirring tank is provided on the stirred tank body. The first and second stirring paddles are disposed within the stirring tank. A first flow guiding device and a second flow guiding device, corresponding to the first and second stirring paddles, are fixedly installed on the sidewalls of the stirring tank. The first and second flow guiding devices are used to convert the flow pattern of the fluid from radial to axial during stirring. The lower end of the first stirring shaft is fixedly connected to the first stirring paddle. The lower end of the second stirring shaft is fixedly connected to the second stirring paddle. The upper end of the first stirring shaft is fixedly connected to the shaft of the first motor. The upper end of the second stirring shaft is fixedly connected to the shaft of the second motor.

[0006] Furthermore, the height of the first flow guiding device from the bottom of the mixing tank is the same as the height of the first stirring paddle from the bottom of the mixing tank; the height of the second flow guiding device from the bottom of the mixing tank is the same as the height of the second stirring paddle from the bottom of the mixing tank.

[0007] Furthermore, the first or second flow guiding device is geometrically represented as a minor arc shape, with the arc of the minor arc shape oriented toward a straight line parallel to the chord of the minor arc shape, and the minor arc shape rotated around the straight line as an axis; the distance between the straight line and the chord of the minor arc shape is equal to the radius of the stirring tank.

[0008] Furthermore, the widths of the first and second agitators are less than or equal to the chord length of the inferior arc.

[0009] Furthermore, the chord length of the inferior bow shape is 1 to 2 times the height of the inferior bow shape.

[0010] Furthermore, the first impeller is a straight-blade turbine impeller; the second impeller is a straight-blade turbine impeller or an inclined-blade turbine impeller.

[0011] Furthermore, the first and second agitators have the same number of blades, and the number of blades in the first and second agitators is 4 to 8.

[0012] Furthermore, the shortest radial distance between the first stirring paddle and the side wall of the stirring tank during rotation is r1 = 0.1R ~ 0.2R; the shortest radial distance between the second stirring paddle and the side wall of the stirring tank during rotation is r2 = 0.1R ~ 0.2R; the shortest radial distance between the first stirring paddle and the second stirring paddle during rotation is r12 = 0.2R ~ 0.6R; where R represents the diameter of the stirring tank.

[0013] Furthermore, the axial distance between the lower end of the first flow guiding device and the bottom surface of the stirring tank is h1 = 0.1H to 0.2H; the axial distance between the upper end of the second flow guiding device and the bottom surface of the stirring tank is h2 = 0.8H to 0.9H; and the axial distance between the upper end of the first flow guiding device and the lower end of the second flow guiding device is h12 = 0.2H to 0.6H, where H represents the depth of the stirring tank.

[0014] The present invention has at least the following beneficial effects

[0015] Compared with traditional technology, this invention sets up two flow guiding devices in the stirring tank corresponding to the first and second stirring blades. When stirring non-Newtonian fluids, it disrupts the structural interface inside and outside the mixing isolation zone in the flow field, enhances the chaotic mixing behavior of the fluid, and allows the non-Newtonian fluid to obtain sufficient stretching and folding effect at the stirring tank wall. This rapidly transforms the fluid from a radial flow pattern to an axial flow pattern, increases the fluid velocity gradient, redistributes the energy input by the stirring blades, strengthens the energy transfer process, and improves mixing efficiency. Attached Figure Description

[0016] Figure 1 A schematic diagram of a dual-axis coupled flow-guiding baffle stirring device;

[0017] Figure 2 This is a schematic diagram of the flow guiding device of the present invention;

[0018] Figure 3 This is a front view schematic diagram of the first and second stirring impellers of the present invention;

[0019] Figure 4 This is a front view schematic diagram of the structure of the dual-axis coupled flow-guiding baffle stirring device of the present invention;

[0020] Figure 5 This is a top view schematic diagram of the structure of the dual-axis coupled flow-guiding baffle stirring device of the present invention;

[0021] Figure 6 This is a schematic diagram of the experimental comparison simulation of the present invention;

[0022] The labels for the attached figures are as follows:

[0023] 1. Stirred reactor body; 2. First motor; 3. Second motor; 4. First stirring shaft; 5. Second stirring shaft; 6. First stirring paddle; 61. Working area of ​​the first stirring paddle; 7. Second stirring paddle; 71. Working area of ​​the second stirring paddle; 8. Straight line; 9. Inferior arc shape; 11. Stirring tank; 101. First flow guiding device; 102. Second flow guiding device. Detailed Implementation

[0024] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0026] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0027] Please see Figure 1 The present invention provides a biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids, comprising:

[0028] The reactor comprises a stirred tank body 1, a first motor 2, a second motor 3, a first stirring shaft 4, a second stirring shaft 5, a first stirring paddle 6, and a second stirring paddle 7. A circular stirring tank 11 is provided on the stirred tank body 1. The first stirring paddle 6 and the second stirring paddle 7 are disposed within the stirring tank 11. A first flow guiding device 101 and a second flow guiding device 102, corresponding to the first stirring paddle 6 and the second stirring paddle 7, are fixedly installed on the side wall of the stirring tank 11. The first flow guiding device 101 and the second flow guiding device 102 are used to convert the flow pattern of the fluid from radial to axial during stirring. The lower end of the first stirring shaft 4 is fixedly connected to the first stirring paddle 6. The lower end of the second stirring shaft 5 is fixedly connected to the second stirring paddle 7. The upper end of the first stirring shaft 4 is fixedly connected to the shaft of the first motor 2. The upper end of the second stirring shaft 5 is fixedly connected to the shaft of the second motor 3.

[0029] In this embodiment, the first motor 2 and the second motor 3 drive the first stirring paddle 6 and the second stirring paddle 7 to rotate in the stirring tank 11 of the stirred reactor body 1, respectively, to stir the non-Newtonian liquid. During the stirring process, the first flow guiding device 101 and the second flow guiding device 102 disrupt the structural interface between the inside and outside of the mixing isolation zone in the flow field, enhance the chaotic mixing behavior of the fluid, and enable the non-Newtonian fluid to obtain sufficient stretching and folding effect at the wall of the stirring tank 11, quickly transforming the fluid from a radial flow pattern to an axial flow pattern, increasing the fluid velocity gradient, redistributing the energy input by the first stirring paddle 6 and the second stirring paddle 7, strengthening the energy transfer process, and improving the mixing efficiency.

[0030] Furthermore, the height of the first flow guiding device 101 from the bottom surface of the mixing tank 11 is the same as the height of the first stirring paddle 6 from the bottom surface of the mixing tank 11; the height of the second flow guiding device 102 from the bottom surface of the mixing tank 11 is the same as the height of the second stirring paddle 7 from the bottom surface of the mixing tank 11.

[0031] In this embodiment, the first stirring paddle 6 and the second stirring paddle 7 are respectively set at the same height as the two flow guiding devices in the stirring tank 11, which shortens the contact time between the fluid and the wall of the stirring tank 11 and effectively stretches and folds the fluid.

[0032] Please see Figure 2 Furthermore, the first flow guiding device 101 or the second flow guiding device 102 is geometrically represented as a minor arc 9, with the arc of the minor arc 9 directed toward a straight line 8 parallel to the chord of the minor arc, and the minor arc 9 rotated one revolution around the straight line 8 as an axis; the distance between the straight line and the chord of the minor arc 9 is equal to the radius R / 2 of the stirring tank 11.

[0033] In this embodiment, the outer circumferential side surfaces of the first flow guiding device 101 and the second flow guiding device 102 are fixedly connected to the side wall of the stirring tank 11. By setting the first flow guiding device 101 and the second flow guiding device 102 to a sub-arc shape 9, it can be fully guaranteed that the non-Newtonian fluid will obtain sufficient stretching and folding effect at the wall of the stirring tank 11, and quickly transform the fluid from a radial flow pattern to an axial flow pattern.

[0034] Furthermore, the widths of the first stirring impeller 6 and the second stirring impeller 7 are less than or equal to the chord length of the inferior arc 9; in this embodiment, the width of the first stirring impeller 6 is H1, and the width of the second stirring impeller 7 is H2, as shown below. Figure 3 As shown; the chord length of the inferior arc 9 is d. By setting H1 and H2 to be less than or equal to d, it can be ensured that the energy input from the first stirring paddle 6 and the second stirring paddle 7 is fully introduced into the flow guiding device, thereby improving the efficiency of energy distribution.

[0035] Furthermore, the chord length of the inferior arc 9 is 1 to 2 times the height of the inferior arc 9; in this embodiment, the chord length of the inferior arc 9 is d, and the height of the inferior arc 9 is r. By setting d to 1 to 2 times r, it can be ensured that the fluid can be fully stretched and folded, and it can also ensure that there is a certain fluid transmission distance between the first stirring paddle 6 and the second stirring paddle 7 and the wall of the stirring tank 11.

[0036] Furthermore, the first impeller 6 is a straight-blade turbine impeller; the second impeller 7 is an oblique-blade turbine impeller.

[0037] In this embodiment, a dual-axis eccentric configuration of inclined blade turbine propeller and straight blade turbine propeller is adopted, which can not only increase the shear force of the fluid, but also significantly improve the main circulation of the fluid. This reduces the low-speed circulation zone at the bottom of the mixing tank 11, and makes the overall velocity distribution in the mixing tank 11 more uniform. This disrupts the inherent structural interface of the flow field, enhances the asymmetry of the flow field structure, thereby disrupting the mixing isolation zone of the flow field and increasing the degree of chaotic mixing of the fluid.

[0038] Furthermore, the first stirring paddle 6 and the second stirring paddle 7 have the same number of blades, and the number of blades in the first stirring paddle 6 and the second stirring paddle 7 is 4 to 8.

[0039] Please see Figure 4 Furthermore, the shortest radial distance between the first stirring paddle 6 and the sidewall of the stirring tank 11 during rotation is r1 = 0.1R ~ 0.2R; the shortest radial distance between the second stirring paddle 7 and the sidewall of the stirring tank 11 during rotation is r2 = 0.1R ~ 0.2R; the shortest radial distance between the first stirring paddle 6 and the second stirring paddle 7 during rotation is r12 = 0.2R ~ 0.6R; where R represents the diameter of the stirring tank; viewed from above, the working area 61 of the first stirring paddle 6 during rotation is a circular surface, and the working area 71 of the second stirring paddle 7 during rotation is a circular surface. Therefore, the shortest radial distances between the first stirring paddle 6 and the sidewall of the stirring tank 11 during rotation, and the shortest radial distances between the second stirring paddle 7 and the sidewall of the stirring tank 11 during rotation are as follows: Figure 5 As shown.

[0040] The above configuration can enhance the fluid coupling between the blades of the first impeller 6 and the second impeller 7, thereby strengthening the fluid transport effect between the blades.

[0041] Please see Figure 5 Furthermore, the axial distance between the lower end of the first flow guiding device 101 and the bottom surface of the stirring tank 11 is h1 = 0.1H to 0.2H; the axial distance between the upper end of the second flow guiding device 102 and the bottom surface of the stirring tank 11 is h2 = 0.8H to 0.9H; the axial distance between the upper end of the first flow guiding device 101 and the lower end of the second flow guiding device 102 is h12 = 0.2H to 0.6H, where H represents the depth of the stirring tank 11.

[0042] The above configuration ensures that the coupling enhancement effect of the first stirring paddle 6 and the second stirring paddle 7 with the flow guiding device, as well as between the two flow guiding devices, reaches the optimal level.

[0043] Experimental simulations were conducted under the same conditions for the stirring of non-Newtonian liquids using a traditional baffle stirring device, a traditional baffleless stirring device, and the novel flow-guiding baffle device provided by this invention. The difference between the traditional baffle stirring device and the flow-guiding baffle device of this invention is that the traditional baffle stirring device lacks the flow-guiding device of this invention; instead, it uses four baffles radially arranged around the sidewall of the stirring tank 11. These four baffles are evenly distributed radially on the sidewall of the stirring tank. Simulation results... Figure 6 As shown, from Figure 6As can be seen from the results, compared with traditional baffle and baffleless stirring devices, the new flow-guiding baffle stirring device can enhance the velocity distribution of the fluid on the wall, reduce the low-speed circulation zone in the flow field, and increase the high-speed circulation chaotic zone in the flow field, thereby enhancing the axial transport process of the fluid, shortening the mixing time of non-Newtonian fluids, and improving the mixing efficiency.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids, characterized in that, include: The stirred reactor vessel (1), first motor (2), second motor (3), first stirring shaft (4), second stirring shaft (5), first stirring paddle (6), and second stirring paddle (7) are provided. A circular stirring tank (11) is provided on the stirred reactor vessel (1). The first stirring paddle (6) and the second stirring paddle (7) are provided in the stirring tank (11). A first flow guiding device (101) and a second flow guiding device (102) corresponding to the first stirring paddle (6) and the second stirring paddle (7) are fixedly provided on the side wall of the stirring tank (11). The first flow guiding device (101) and the second flow guiding device (102) are used to convert the flow pattern of the fluid from radial to axial during stirring. The lower end of the first stirring shaft (4) is fixedly connected to the first stirring paddle (6). The lower end of the second stirring shaft (5) is fixedly connected to the second stirring paddle (7). The upper end of the first stirring shaft (4) is fixedly connected to the rotating shaft of the first motor (2). The upper end of the second stirring shaft (5) is fixedly connected to the rotating shaft of the second motor (3). The height of the first flow guiding device (101) from the bottom surface of the mixing tank (11) is the same as the height of the first stirring paddle (6) from the bottom surface of the mixing tank (11); the height of the second flow guiding device (102) from the bottom surface of the mixing tank (11) is the same as the height of the second stirring paddle (7) from the bottom surface of the mixing tank (11); The first flow guiding device (101) or the second flow guiding device (102) is geometrically represented as a minor arc (9), with the arc of the minor arc (9) directed toward a straight line (8) parallel to the chord of the minor arc, and the minor arc (9) rotated around the straight line (8) as an axis; the distance between the straight line (8) and the chord of the minor arc (9) is equal to the radius of the stirring tank (11).

2. The biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids according to claim 1, characterized in that, The widths of the first stirring blade (6) and the second stirring blade (7) are less than or equal to the chord length of the inferior arc (9).

3. A biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids according to claim 2, characterized in that, The chord length of the inferior bow (9) is 1 to 2 times the height of the inferior bow (9).

4. The biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids according to claim 1, characterized in that, The first impeller (6) is a straight-bladed turbine impeller; the second impeller (7) is a slanted-bladed turbine impeller.

5. A biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids according to claim 4, characterized in that, The first stirring paddle (6) and the second stirring paddle (7) have the same number of blades, and the first stirring paddle (6) and the second stirring paddle (7) have 4 to 8 blades.

6. A biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids according to claim 1, characterized in that, The shortest radial distance between the first stirring paddle (6) and the side wall of the stirring tank (11) during rotation is r1 = 0.1R ~ 0.2R; the shortest radial distance between the second stirring paddle (7) and the side wall of the stirring tank (11) during rotation is r2 = 0.1R ~ 0.2R; the shortest radial distance between the first stirring paddle (6) and the second stirring paddle (7) during rotation is r12 = 0.2R ~ 0.6R; where R represents the diameter of the stirring tank.

7. A biaxially coupled flow-guiding baffle stirring device for mixing non-Newtonian fluids according to claim 1, characterized in that, The shortest axial distance between the lower end of the first flow guiding device (101) and the bottom surface of the stirring tank (11) is h1 = 0.1H ~ 0.2H; the longest axial distance between the upper end of the second flow guiding device (102) and the bottom surface of the stirring tank (11) is h2 = 0.8H ~ 0.9H; the shortest axial distance between the upper end of the first flow guiding device (101) and the lower end of the second flow guiding device (102) is h12 = 0.2H ~ 0.6H, where H represents the depth of the stirring tank (11).

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