Iterative stirring paddle

Abstract

The invention relates to the technical field of fluid mixing devices, in particular to an iterative stirring paddle. Comprising an iterative stirring mechanism which is assembled on a stirring shaft and used for fluid mixing, and the iterative stirring mechanism comprises a fixing sleeve, a disc and a plurality of iterative blades. According to the invention, the plurality of iteration blades are arranged, in the rotation process of the blade, on the premise of keeping the blade area unchanged, the stirring power consumption is saved, the concave-convex small rectangular structures on the edges of the blades can increase the shearing range and the shearing strength of fluid, meanwhile, a series of disturbing flows are generated, and the pressure difference between the front and back parts of the blades is reduced; a trailing vortex structure at the edge of the blade is destroyed; the trailing vortex size of the blade is reduced; the turbulence strength of a flow field and the uniformity of turbulence energy distribution are improved; the flow speed of fluid is increased, the transfer process of momentum and energy among fluid particles is enhanced, the energy utilization rate of the blade is increased, the structural instability of a mixing isolation area in the flow field is induced, and the mixing time of the fluid is shortened; the mixing efficiency and the mixing degree of the fluid are improved.

Description

Technical Field

[0001] The invention relates to the technical field of fluid mixing devices, and in particular to an iterative stirring paddle. Background Art

[0002] With the development of industries such as synthetic rubber, coatings, food, cosmetics, bioengineering, and pharmaceutical engineering, more and more stirring operations involving high-viscosity fluids are involved. People usually increase the mixing effect of the fluid by increasing the stirring speed, but the energy consumption of the stirring equipment is in a cubic relationship with the stirring speed. Increasing the stirring speed will lead to a sharp increase in energy consumption demand, and may also cause damage to components such as the stirring shaft due to exceeding the carrying capacity. At the same time, in the fields of bioengineering and pharmaceutical engineering, since media such as proteins and cells are sensitive to shearing, strong shearing will destroy these media. Therefore, in these cases, the stirring paddle speed is generally low, and the fluid in the stirring tank is in a laminar state. The flow field in the laminar stirring tank usually forms two different areas: a mixed isolation zone that does not participate in convective flow and a chaotic mixing zone for rapid flow transmission. The fluid particles in the chaotic mixing zone are stretched according to the Lyapunov exponent, the chaotic mixing degree of the fluid is high, and the fluid mixing effect is good. The fluid particles in the mixed isolation zone can only be stretched linearly, the coupling degree between the fluids is low, the chaotic mixing degree of the fluid is low, and the transmission mainly relies on molecular diffusion. Since the molecular diffusion rate is relatively slow, the mixed isolation zone exists in the flow field for a long time, and the fluid mixing effect is poor.

[0003] As the core component of the stirring equipment, the impeller inputs mechanical energy to the fluid in the stirring tank. The type and structure of the impeller largely determine the formation and evolution of the flow field structure in the stirring tank, affecting the efficiency and degree of fluid mixing. During the stirring process, the traditional straight-blade impeller will form a large tail vortex at the outer edge of the blade. Most of the energy of the impeller will be consumed in the tail vortex, and less energy is actually used for fluid mixing and transfer, resulting in low energy utilization of the impeller, poor uniformity of flow field turbulence intensity and flow velocity distribution, and failure to destroy the structure of the mixing isolation zone and strengthen the mixing and transfer of fluids between the mixing isolation zone and the chaotic mixing zone, resulting in poor fluid mixing effect.

[0004] In the prior art, in order to solve the above problems, the blade structure of the stirring paddle can be designed as a structure with fractal characteristics. For example, the stirring paddle is designed as a hollow structure based on equilateral triangle iteration, or as a concave-convex sheet structure based on square iteration, or as a notched stirring paddle with fractal arrangement, but this type of stirring paddle still has certain problems in the fluid mixing process. With the increase of the number of structural iterations of this type of stirring paddle, the blade area of ​​the stirring paddle will gradually decrease, which will cause the interaction cross section between the blade and the fluid to decrease, and the interaction force between the blade and the fluid to decrease. The turbulence degree of the fluid, the fluid velocity and the mixing efficiency may not necessarily continue to improve with the continuous increase in the number of iterations. For example, the impeller is designed as a sheet structure based on Z-shaped superposition. Although the blade area of ​​this type of impeller remains unchanged as the number of structural iterations increases, due to the limitation of its Z-shaped structure, the initial blade area of ​​this type of impeller is only half of the blade area of ​​a straight-blade impeller. The area of ​​interaction between the blade and the fluid is not large, resulting in uneven distribution of turbulence intensity and velocity in the flow field, and low transmission efficiency between fluid particles. As the number of structural iterations increases, the structural strength of the links between the Z-shaped ones is very weak, which limits its use scenarios. For example, it cannot run at high speed, or the stirring medium is a high-viscosity fluid or a high-solid content system, which may cause the connection between the Z-shaped ones to break, hindering some practical applications of this type of impeller. For this reason, we propose an iterative impeller. Summary of the invention

[0005] The object of the present invention is to provide an iterative stirring paddle to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] An iterative stirring paddle comprises an iterative stirring mechanism mounted on a stirring shaft for fluid mixing, the iterative stirring mechanism comprising a fixed sleeve, a disc and a plurality of iterative blades, the outer side of the stirring shaft is fixed with a fixed sleeve, the outer side of the fixed sleeve is provided with a disc, a plurality of blades are evenly arranged on the disc, and the main structure of the iterative blade is a concave-convex sheet structure with a similar iterative rule.

[0008] Preferably, the main structure of the iterative blade is obtained by adopting the following iterative rule: each side of the rectangular blade that is not in contact with the disk is evenly divided into 2n small parts, where n≥3;

[0009] Then, each side of the rectangular blade that is not in contact with the disk is evenly divided into 2m segments, where m ≥ 1; each segment has n / m small portions, where the values ​​of n and m must satisfy that n / m is an integer, and each segment is numbered consecutively in a clockwise or counterclockwise direction;

[0010] Then, a small rectangle is protruded outward or recessed inward on the odd-numbered segment with the side length of the kth small portion as the base, where 2≤k<n / m, and k is counted in a clockwise or counterclockwise direction; the ratio of the longitudinal length to the transverse length of the small rectangle protruding outward or recessed inward is equal to the ratio of the longitudinal length to the transverse length of the initial rectangular blade;

[0011] Then, a small rectangle is concave inward or convex outward with the side length of the kth small part on the even-numbered segment as the base, where 2≤k<n / m; the ratio of the longitudinal length to the transverse length of the small rectangle concave inward or convex outward is equal to the ratio of the longitudinal length to the transverse length of the initial rectangle, and the main structure of an iterative blade is obtained.

[0012] Preferably, the above division action is repeated for each edge of the main structure of the blade of one iteration that is not in contact with the disk according to the iteration rule, so that the main structure of the blade of multiple iterations can be obtained.

[0013] Preferably, in the main structure of the iterative blade, during the iteration process, the ratio of the longitudinal length to the transverse length of the small rectangle that is concave inwards or convex outwards remains unchanged from the ratio of the longitudinal length to the transverse length of the initial rectangle.

[0014] Preferably, in the main structure of the iterative blade, the number of small rectangles that are recessed inwards during the iteration process is equal to the number of small rectangles that are protruded outwards.

[0015] Preferably, the main structure of the iterative blade has an increasing number of small rectangles that are recessed inwards or protruded outwards as the number of iterations increases.

[0016] Preferably, as the number of iterations of the main structure of the iterative blade increases, the longitudinal length and the lateral length of the small rectangle that is concave inwards or convex outwards gradually decrease.

[0017] Preferably, the main structure of the iterative blade maintains an area of ​​the blade unchanged during the iterative process.

[0018] Preferably, as the number of iterations of the main structure of the iterative blade increases, the area of ​​the small rectangle that is concave inwards or convex outwards gradually decreases.

[0019] Preferably, the circumference of the main structure of the iterative blade gradually increases during the iteration process, and the longitudinal length and the lateral length of the entire blade gradually increase during the iteration process.

[0020] It can be seen without a doubt that the above-mentioned technical solution of the present application can definitely solve the technical problem to be solved by the present application.

[0021] At the same time, through the above technical solutions, the present invention has at least the following beneficial effects:

[0022] The present invention sets a plurality of iterative blades. During the rotation process, the blade saves stirring power consumption under the premise of maintaining the blade area unchanged. The concave and convex small rectangular structure on the blade edge can increase the shear range and shear strength of the fluid, and generate a series of disturbed flows at the same time, reduce the pressure difference before and after the blade, destroy the tail vortex structure at the blade edge, reduce the size of the blade tail vortex, improve the turbulent intensity of the flow field and the uniformity of the turbulent kinetic energy distribution, increase the flow velocity of the fluid, strengthen the momentum and energy transfer process between fluid particles, improve the blade energy utilization rate, induce the instability of the mixing isolation zone structure in the flow field, shorten the mixing time of the fluid, and improve the mixing efficiency and mixing degree of the fluid. In addition, this iterative method of the blade structure always maintains the blade as a complete sheet structure, maintains the blade area unchanged during the iterative process, and can effectively reduce the pressure difference before and after the blade, and reduce the resistance encountered by the blade in the fluid, which can effectively ensure the stability and bearing strength of such iterative blade structure and broaden the scope of application of the stirring paddle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0024] Figure 1 A schematic diagram of the iterative stirring paddle structure provided by the present invention;

[0025] Figure 2 A schematic diagram of a stirring device for an iterative stirring paddle provided by the present invention;

[0026] Figure 3 It is a schematic diagram of a rectangular blade structure without iteration;

[0027] Figure 4 This is a schematic diagram of an iterative blade structure;

[0028] Figure 5 It is a schematic diagram of the secondary iterative blade structure;

[0029] Figure 6 This is the data table of stirring power consumption experimental results for Experiment 1;

[0030] Figure 7 This is the data table of the fluid mixing time experimental results of Experiment 1;

[0031] Figure 8 This is the data table of the fluid mixing time experimental results of Experiment 2;

[0032] Fig. 9This is the data table of the fluid mixing time experimental results of Experiment 3;

[0033] Fig.10 This is the data table of the fluid mixing time experimental results of Experiment 4;

[0034] Fig.11 This is the data table of stirring power consumption experimental results for Experiment 5;

[0035] Fig.12 This is the data table of the fluid mixing time experimental results of Experiment 5;

[0036] Fig.13 This is the data table of the fluid mixing time experimental results of Experiment 6;

[0037] Fig.14 This is the data table of the fluid mixing time experimental results of Experiment 7;

[0038] Fig.15 This is the data table of the fluid mixing time experimental results for Experiment 8.

[0039] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0040] In the figure: 1. Motor; 2. Stirring shaft; 3. Stirring tank; 4. Baffle; 5. Iterative blade; 6. Disc; 7. Fixed sleeve. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] Reference Figure 1-5 An iterative stirring paddle includes an iterative stirring mechanism mounted on a stirring shaft 2 for fluid mixing, the iterative stirring mechanism includes a fixed sleeve 7, a disc 6 and a plurality of iterative blades 5, the outer side of the stirring shaft 2 is fixed with a fixed sleeve 7, the outer side of the fixed sleeve 7 is provided with a disc 6, and a plurality of blades 5 are evenly arranged on the disc 6, and the main structure of the iterative blade 5 is a concave-convex sheet structure with a similar iterative rule.

[0043] The main structure of the iterative blade 5 is obtained by adopting the following iterative rule: each side of the rectangular blade that is not in contact with the disk is first divided into 2n small parts, where n≥3;

[0044] Then, each side of the rectangular blade that is not in contact with the disk is evenly divided into 2m segments, where m ≥ 1; each segment has n / m small portions, where the values ​​of n and m must satisfy that n / m is an integer, and each segment is numbered consecutively in a clockwise or counterclockwise direction;

[0045] Then, a small rectangle is protruded outward or recessed inward on the odd-numbered segment with the side length of the kth small portion as the base, where 2≤k<n / m, and k is counted in a clockwise or counterclockwise direction; the ratio of the longitudinal length to the transverse length of the small rectangle protruding outward or recessed inward is equal to the ratio of the longitudinal length to the transverse length of the initial rectangular blade;

[0046] Then, a small rectangle is recessed inward or protruded outward with the side length of the kth small part on the even-numbered segment as the base, where 2≤k<n / m; the ratio of the longitudinal length to the transverse length of the small rectangle recessed inward or protruding outward is equal to the ratio of the longitudinal length to the transverse length of the initial rectangle, and at this time, the main structure of an iterative blade 5 is obtained.

[0047] The above division action is repeated for each edge of the main structure of the first-iteration blade 5 that is not in contact with the disk according to the iterative rule, so that the main structure of the blade 5 of multiple iterations can be obtained.

[0048] The main structure of the iterative blade 5 has a main structure in which the ratio of the longitudinal length to the transverse length of the small rectangle that is concave inwards or convex outwards during the iteration process and a main structure in which the main structure of the iterative blade 5 is concave inwards or convex outwards during the iteration process, while the ratio of the longitudinal length to the transverse length of the initial rectangle remains unchanged.

[0049] In the iterative process, the number of the small rectangles that are recessed inwards and the number of the small rectangles that are protruded outwards of the main structure of the iterative blade 5 are equal.

[0050] As the number of iterations of the main structure of the iterative blade 5 increases, the number of small rectangles that are concave inwards or convex outwards gradually increases.

[0051] As the number of iterations of the main structure of the iterative blade 5 increases, the longitudinal length and the lateral length of the small rectangle that is concave inward or convex outward gradually decrease.

[0052] The main structure of the iterative blade 5 has an area that remains unchanged during the iterative process.

[0053] As the number of iterations of the main structure of the iterative blade 5 increases, the area of ​​the small rectangle that is concave inwards or convex outwards gradually decreases.

[0054] The main structure of the iterative blade 5 has a circumference that gradually increases during the iteration process, and the main structure of the iterative blade 5 has a longitudinal length and a lateral length that gradually increase during the iteration process.

[0055] The main structure of the iterative blade 5 gradually increases the shear range of the fluid by the blade during the iterative process.

[0056] An iterative stirring paddle also includes a motor 1 arranged on a stirring tank 3, wherein the output end of the motor 1 is fixed to a stirring shaft 2, and a baffle 4 is arranged on the outer side of the stirring tank 3.

[0057] The disc has a through hole, the fixing sleeve is passed through the through hole, and the plurality of blades are connected to the outer peripheral side of the disc.

[0058] For example, taking an iterative paddle as an example, Figure 4 shown. Figure 3 The schematic diagram of the rectangular blade structure without iteration is shown in Figure 1. The longitudinal length L1 of the rectangular blade is 4.86 cm, the transverse length L2 is 5.4 cm, the ratio of the longitudinal length to the transverse length of the rectangular blade is 0.9, the circumference is 20.52 cm, and the blade area is 24.786 cm. 2 . In the first iteration, each side of the rectangular blade that is not in contact with the disk is first divided into 6 small parts, and then each side of the rectangular blade that is not in contact with the disk is divided into 2 sections, and each section is numbered consecutively in a clockwise direction. Then, on the odd-numbered sections, a small rectangle protruding outward is made with the side length of the second section (counted in a clockwise direction) as the base, and a small rectangle concave inward is made with the side length of the second section (counted in a clockwise direction) on the even-numbered sections as the base. The longitudinal length L3 of the small rectangle protruding outward and the small rectangle concave inward is 0.81 cm, and the transverse length L4 is 0.9 cm. The ratio of the longitudinal length to the transverse length of the small rectangle is 0.9, and the number of small rectangles protruding outward is equal to the number of small rectangles concave inward. The longitudinal length of the blade in one iteration is 6.48 cm, the transverse length is 6.3 cm, the circumference is 30.6 cm, and the blade area is always 24.786 cm 2 .

[0059] Experiment 1: Using the agitator paddle in the above example, and referring to Figure 2 The stirring shaft 2 is driven by the motor 1. The stirring shaft 2 is equipped with an iterative stirring paddle, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the baffle 4 width is 0.048m, the liquid height is maintained at 0.5m, and the liquid is a 1.5% sodium carboxymethyl cellulose solution. The acid-base decolorization experiment is used to measure the fluid mixing time under different stirring speed conditions. At the same time, the stirring torque is measured using a torque sensor, and the stirring power consumption is calculated. The stirring power consumption experimental results are shown in Figure 6 ,from Figure 6 It can be seen that under the stirring speed conditions of 130rpm, 170rpm and 210rpm, the stirring power consumption of the single-iteration stirring paddle disclosed in the present invention is reduced by 3.47%, 4.45% and 4.73% respectively compared with the rectangular stirring paddle without iteration. The experimental results of fluid mixing time are shown in Figure 7 ,from Figure 7It can be seen that under the conditions of stirring speeds of 50rpm, 75rpm and 100rpm respectively, the fluid mixing time of the single-iteration stirring paddle disclosed in the present invention is shortened by 14.8%, 18.18% and 15.79% compared with the single-iteration fractal combination stirring paddle composed of a hollow structure and a sheet structure based on equilateral triangle iteration.

[0060] Experiment 2: Using the agitator paddle in the above example, and referring to Figure 2 The stirring shaft 2 is driven by the motor 1. The stirring shaft 2 is equipped with a first-order stirring paddle, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the width of the baffle 4 is 0.048m, the liquid height is maintained at 0.48m, and the liquid is a 1.5% sodium carboxymethyl cellulose solution. The acid-base decolorization experiment is used to measure the fluid mixing time under different stirring speed conditions. The fluid mixing time experimental results are shown in Figure 8 ,from Figure 8 It can be seen that under the stirring speed conditions of 50 rpm, 100 rpm and 150 rpm respectively, the fluid mixing time of the single-iteration stirring paddle disclosed in the present invention is shortened by 17.86%, 36% and 36.36% compared with the single-iteration stirring paddle based on Z-shaped superposition.

[0061] Experiment 3: Using the agitator paddle in the above example, and referring to Figure 2 The stirring shaft 2 is driven by the motor 1. The stirring shaft 2 is equipped with a first-order stirring paddle, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the width of the baffle 4 is 0.048m, the liquid height is maintained at 0.6m, and the liquid is a 2.0% sodium carboxymethyl cellulose solution. The acid-base decolorization experiment is used to measure the fluid mixing time under different stirring speed conditions. The fluid mixing time experimental results are shown in Fig. 9 ,from Fig. 9 It can be seen that when the stirring speed is 60rpm, 120rpm and 180rpm respectively, the fluid mixing time of the single-iteration stirring paddle disclosed in the present invention is shortened by 12.5%, 14.29% and 12% compared with the single-iteration self-similar stirring paddle based on square iteration.

[0062] Experiment 4: Using the agitator paddle in the above example, and refer to Figure 2 The stirring shaft 2 is driven by the motor 1. The stirring shaft 2 is equipped with a first-order stirring paddle, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the width of the baffle 4 is 0.048m, the liquid height is maintained at 0.5m, and the liquid is a 2% xanthan gum solution. The acid-base decolorization experiment is used to measure the fluid mixing time under different stirring power consumption conditions. The fluid mixing time experimental results are shown in Fig.10 ,from Fig.10 It can be seen that under the conditions of stirring power consumption of 17.5 W, 27.0 W and 42.0 W respectively, the fluid mixing time of the iterative stirring paddle disclosed in the present invention is shortened by 9.26%, 12.25% and 22.22% compared with the iterative stirring paddle with fractal arrangement incisions.

[0063] Take the quadratic fractal iteration as an example, Figure 5 shown. Figure 3 The schematic diagram of the rectangular blade structure without iteration is shown in Figure 1. The longitudinal length L1 of the rectangular blade is 4.86 cm, the transverse length L2 is 5.4 cm, the ratio of the longitudinal length to the transverse length of the rectangular blade is 0.9, the circumference is 20.52 cm, and the blade area is 24.786 cm. 2 . In the second iteration, each side of the blade that is not in contact with the disk in the first iteration is first divided into 6 small parts, and then each side of the blade that is not in contact with the disk in the first iteration is divided into 2 sections, and each section is numbered consecutively in a clockwise direction. Then, on the odd-numbered sections, a small rectangle protruding outward is made with the side length of the second section (counted in a clockwise direction) as the base, and a small rectangle concave inward is made with the side length of the second section (counted in a clockwise direction) on the even-numbered sections. The longitudinal length L5 of the small rectangle protruding outward and the small rectangle concave inward is 0.135cm, and the transverse length L6 is 0.15cm. The ratio of the longitudinal length to the transverse length of the small rectangle is 0.9, and the number of small rectangles protruding outward is equal to the number of small rectangles concave inward. The longitudinal length of the second iteration blade is 6.75cm, the transverse length is 6.45cm, the circumference is 47.64cm, and the blade area is always 24.786cm 2 .

[0064] Experiment 5: Using the second iteration of the stirring paddle in the above example, and refer to Figure 2 The stirring shaft 2 is driven by the motor 1. A secondary iterative stirring paddle is installed on the stirring shaft 2, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the width of the baffle 4 is 0.048m, the liquid height is maintained at 0.5m, and the liquid is a 1.5% sodium carboxymethyl cellulose solution. Acid-base decolorization experiments are carried out under different stirring speed conditions. At the same time, the stirring torque is measured by a torque sensor, and the stirring power consumption is calculated. The stirring power consumption experimental results are shown in Fig.11 ,from Fig.11 It can be seen that under the stirring speed conditions of 130rpm, 170rpm and 210rpm, the stirring power consumption of the secondary iterative stirring paddle disclosed in the present invention is reduced by 5.56%, 5.99% and 5.72% respectively compared with the rectangular stirring paddle without iteration. The experimental results of fluid mixing time are shown in Fig.12 ,from Fig.12It can be seen that under the stirring speed conditions of 50rpm, 75rpm and 100rpm respectively, the secondary iterative stirring paddle disclosed in the present invention is compared with the secondary iterative fractal combination stirring paddle composed of a hollow structure and a sheet structure based on equilateral triangle iteration, and the fluid mixing time is shortened by 20%, 15% and 17.65%.

[0065] Experiment 6: Using the second iteration of the stirring paddle in the above example, and refer to Figure 2 The stirring shaft 2 is driven by the motor 1. A secondary iterative stirring paddle is installed on the stirring shaft 2, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the width of the baffle 4 is 0.048m, the liquid height is maintained at 0.48m, the liquid is 1.5% sodium carboxymethyl cellulose solution, and the acid-base decolorization experiment is carried out under different stirring speed conditions. The fluid mixing time experimental results are shown in Fig.13 ,from Fig.13 It can be seen that under the stirring speed conditions of 50rpm, 100rpm and 150rpm respectively, the secondary iterative stirring paddle disclosed in the present invention shortens the fluid mixing time by 23.08%, 39.13% and 40% compared with the secondary iterative stirring paddle based on Z-shaped superposition.

[0066] Experiment 7: Using the second iteration of the stirring paddle in the above example, and refer to Figure 2 The stirring shaft 2 is driven by the motor 1. A secondary iterative stirring paddle is installed on the stirring shaft 2, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the width of the baffle 4 is 0.048m, the liquid height is maintained at 0.6m, and the liquid is a 2.0% sodium carboxymethyl cellulose solution. The acid-base decolorization experiment is used to measure the fluid mixing time under different stirring speed conditions. The fluid mixing time experimental results are shown in Fig.14 ,from Fig.14 It can be seen that when the stirring speed is 60rpm, 120rpm and 180rpm respectively, the fluid mixing time of the quadratic iterative stirring paddle disclosed in the present invention is shortened by 13.33%, 15.38% and 13.04% compared with the quadratic iterative self-similar stirring paddle based on square iteration.

[0067] Experiment 8: Using the second iteration of the stirring paddle in the above example, and refer to Figure 2 The stirring shaft 2 is driven by the motor 1. A secondary iterative stirring paddle is installed on the stirring shaft 2, and the fluid is mixed and stirred in the stirring tank 3. The diameter of the stirring tank 3 is 0.48m, the tank height is 1m, the width of the baffle 4 is 0.048m, the liquid height is maintained at 0.5m, and the liquid is a 2% xanthan gum solution. The acid-base decolorization experiment is used to measure the fluid mixing time under different stirring power consumption conditions. The fluid mixing time experimental results are shown in Fig.15 ,from Fig.15It can be seen that under the conditions of stirring power consumption of 17.5 W, 27.0 W and 42.0 W respectively, the fluid mixing time of the secondary iterative stirring paddle disclosed in the present invention is shortened by 8.33%, 9.52% and 25% compared with the secondary iterative stirring paddle with fractal arrangement incisions.

[0068] From the above, we can know that:

[0069] The present invention is directed to the following technical problems: In the prior art, a stirring paddle is designed as a hollow structure based on an iterative equilateral triangle, or as a concave-convex sheet structure based on an iterative square, or as a stirring paddle with a fractal arrangement of cuts. As the number of structural iterations of this type of stirring paddle increases, the paddle area of ​​the stirring paddle will gradually decrease, resulting in a decrease in the interaction cross-section between the paddle and the fluid, a decrease in the interaction force between the paddle and the fluid, and the turbulence degree of the fluid, the fluid velocity, and the mixing efficiency may not necessarily continue to increase with an increasing number of iterations. Alternatively, the impeller is designed as a sheet structure based on Z-shaped superposition. Although the blade area of ​​this type of impeller remains unchanged as the number of structural iterations increases, the initial blade area of ​​this type of impeller is only half of the blade area of ​​a straight-blade impeller due to the limitation of its Z-shaped structure. The area of ​​interaction between the blade and the fluid is not large, resulting in uneven distribution of turbulence intensity and velocity in the flow field, and low transmission efficiency between fluid particles. As the number of structural iterations increases, the structural strength of the connection between the Z-shaped parts is very weak, which limits its use scenarios. For example, it cannot run at high speeds, or the stirring medium is a high-viscosity fluid or a high-solid content system, which may cause the connection between the Z-shaped parts to break, hindering some practical applications of this type of impeller. By adopting the technical solutions of the above embodiments and through the above settings, the present application will certainly be able to solve the above technical problems and achieve the following technical effects:

[0070] The present invention sets a plurality of iterative blades 5. During the rotation process, the blade saves stirring power consumption while maintaining the blade area unchanged. The concave and convex small rectangular structure on the blade edge can increase the shear range and shear strength of the fluid, and generate a series of disturbed flows at the same time, reduce the pressure difference before and after the blade, destroy the tail vortex structure at the blade edge, reduce the size of the blade tail vortex, increase the turbulent intensity of the flow field and the uniformity of the turbulent kinetic energy distribution, increase the flow velocity of the fluid, strengthen the momentum and energy transfer process between fluid particles, improve the blade energy utilization rate, induce the instability of the mixing isolation zone structure in the flow field, shorten the mixing time of the fluid, and improve the mixing efficiency and mixing degree of the fluid. In addition, this iterative method of the blade structure always maintains the blade as a complete sheet structure, maintains the blade area unchanged during the iterative process, and can effectively reduce the pressure difference before and after the blade, and reduce the resistance encountered by the blade in the fluid, which can effectively ensure the stability and bearing strength of this type of iterative blade structure and broaden the scope of application of the stirring paddle.

[0071] The electrical components in this device are all existing technologies, and its model is only one of them. As long as the electrical components can achieve the purpose of this device, they can be used. All electrical components in the device are connected to their compatible power supplies through wires, and a suitable controller should be selected according to actual conditions to meet control requirements. The specific connection and control sequence should refer to the following working principle. The electrical connection is completed in the order of working in sequence. The detailed connection means are well known in the art, and the electrical control will not be explained again.

[0072] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific embodiments, or to perform equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. An iterative stirring paddle, comprising an iterative stirring mechanism mounted on a stirring shaft (2) for fluid mixing, characterized in that: The iterative stirring mechanism comprises a fixed sleeve (7), a disc (6) and a plurality of iterative blades (5); the fixed sleeve (7) is fixed to the outer side of the stirring shaft (2); the disc (6) is sleeved on the outer side of the fixed sleeve (7); a plurality of blades (5) are evenly arranged on the disc (6); the main structure of the iterative blades (5) is a concave-convex sheet structure with a similar iterative regularity.

2. An iterative stirring paddle according to claim 1, characterized in that: The main structure of the iterative blade (5) is obtained by adopting the following iterative rule: each side of the rectangular blade that is not in contact with the disk is evenly divided into 2n small parts, where n≥3; Then, each side of the rectangular blade that is not in contact with the disk is evenly divided into 2m segments, where m ≥ 1; each segment has n / m small portions, where the values ​​of n and m must satisfy that n / m is an integer, and each segment is numbered consecutively in a clockwise or counterclockwise direction; Then, a small rectangle is protruded outward or recessed inward on the odd-numbered segment with the side length of the kth small portion as the base, where 2≤k<n / m, and k is counted in a clockwise or counterclockwise direction; the ratio of the longitudinal length to the transverse length of the small rectangle protruding outward or recessed inward is equal to the ratio of the longitudinal length to the transverse length of the initial rectangular blade; Then, a small rectangle is concave inward or convex outward with the side length of the kth small part on the even-numbered segment as the base, where 2≤k<n / m; the ratio of the longitudinal length to the transverse length of the small rectangle concave inward or convex outward is equal to the ratio of the longitudinal length to the transverse length of the initial rectangle, and at this time, the main structure of an iterative blade (5) is obtained.

3. An iterative stirring impeller according to claim 2, characterized in that: By repeating the above division action for each edge of the main structure of the first-iteration blade (5) that is not in contact with the disk according to the iterative rule, the main structure of the multi-iteration blade (5) can be obtained.

4. The iterative stirring paddle according to claim 2, characterized in that: The main structure of the iterative blade (5) has a main structure in which the ratio of the longitudinal length to the transverse length of the small rectangle that is concave inwards or convex outwards during the iteration process remains unchanged from the ratio of the longitudinal length to the transverse length of the initial rectangle.

5. The iterative stirring impeller according to claim 2, characterized in that: The main structure of the iterative blade (5) has a main body structure in which the number of small rectangles that are recessed inwards and the number of small rectangles that are protruded outwards are equal during the iteration process.

6. The iterative stirring impeller according to claim 2, characterized in that: As the number of iterations of the main structure of the iterative blade (5) increases, the number of small rectangles that are concave inwards or convex outwards gradually increases.

7. The iterative stirring impeller according to claim 2, characterized in that: The main structure of the iterative blade (5) gradually decreases in longitudinal length and transverse length of the small rectangle that is concave inwards or convex outwards as the number of iterations increases.

8. The iterative stirring impeller according to claim 2, characterized in that: The main structure of the iterative blade (5) keeps the area of ​​the blade unchanged during the iterative process.

9. The iterative stirring impeller according to claim 8, characterized in that: As the number of iterations of the main structure of the iterative blade (5) increases, the area of ​​the small rectangle that is concave inwards or convex outwards gradually decreases.

10. The iterative stirring impeller according to claim 2, characterized in that: The main structure of the iterative blade (5) has a circumference that gradually increases during the iteration process, and the main structure of the iterative blade (5) has an overall longitudinal length and a lateral length that gradually increase during the iteration process.

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