Agitator for dispersing gas and design method thereof

Abstract

The present application discloses an agitator for dispersing gas and a design method thereof, wherein the agitator comprises an agitator shaft and a porous blade mounted on the agitator shaft; the porous blade is provided with a plurality of air outlet holes, and the air inlet end of the air outlet hole is connected to the air vent hole provided at the center of the agitator shaft, so that air passes through the air vent hole into the porous blade and flows out along the air outlet hole, and then the air is distributed in the process that the porous blade rotates with the agitator shaft. The overall structure of the agitator is designed by a design method. The beneficial effects of the present application are as follows: on the basis of the structure of a traditional agitator, air outlet holes are provided on the blades to form porous blades, and air distribution is achieved by ventilating the porous blades, so that the function of the traditional air distributor can be integrated into the agitator, thereby simplifying the equipment structure of the agitation process and improving the efficiency of air dispersion.

Description

Technical Field

[0001] The present application relates to the field of stirring technology, and in particular to a stirrer for dispersing gas and a design method thereof. Background Art

[0002] In the traditional aeration and stirring process, an air distributor is usually required to achieve effective gas dispersion. The traditional air distributor is usually installed at the bottom of the stirring tank, with the nozzle facing the center of the bottom of the fermentation tank and maintaining a suitable distance from the bottom of the tank. The high-speed airflow passes through the bottom of the tank to recoil and disperse the air well. The dispersed rising bubbles are further broken into small bubbles by the agitator to achieve the purpose of fully mixing with the fermentation liquid. However, the traditional air distributor has certain limitations, such as complex structure, difficult installation and maintenance, and low gas dispersion rate. Summary of the invention

[0003] One of the objects of the present application is to provide a stirrer for dispersing gas that can solve at least one of the defects in the above-mentioned background technology.

[0004] Another object of the present application is to provide a design method for an agitator for dispersing gas that can solve at least one of the defects in the above-mentioned background technology.

[0005] In order to achieve at least one of the above-mentioned purposes, the technical solution adopted in the present application is: a stirrer for dispersing gas, comprising a stirring shaft and a porous blade installed on the stirring shaft; a plurality of air outlet holes are arranged on the porous blade, and the air inlet end of the air outlet hole is connected to the air vent arranged in the center of the stirring shaft, so that air can enter the porous blade through the air vent and flow out along the air outlet, thereby distributing air in the process that the porous blade rotates with the stirring shaft.

[0006] Preferably, the opening direction of the air outlet is opposite to the rotation direction of the porous blades.

[0007] Preferably, the porous blade is provided with at least one group of air outlet holes along the axial direction of the stirring shaft, the multiple air outlet holes in each group are arranged radially along the stirring shaft, and the diameters of the multiple air outlet holes in each group increase sequentially from near to far according to the distance from the stirring shaft.

[0008] Preferably, the distance between two adjacent air outlet holes in each group increases from near to far according to the distance to the stirring shaft.

[0009] Preferably, an axially extending air inlet is provided on one side of the porous blade close to the stirring shaft, and a plurality of groups of air outlet holes are connected with the air vents of the stirring shaft through the air inlet; assuming that the spacing between the air outlet holes is S, and the distance between the air outlet holes and the air inlet is L; except for the air outlet hole closest to the air inlet, the diameters of the remaining air outlet holes are d∝(S / L)^(1 / 5).

[0010] Preferably, a ventilation pipe is radially extended on the side of the stirring shaft, and the porous blades are connected to the stirring shaft through the ventilation pipe; the sum of the areas of all the air outlet holes on the porous blades is less than or equal to the cross-sectional area of ​​the air inlet hole arranged in the center of the ventilation pipe.

[0011] Preferably, the porous blades are manufactured using metal powder 3D printing technology.

[0012] A design method for the above-mentioned agitator for dispersing gas includes the following design steps:

[0013] S100: Preliminary determination of the structural dimensions of the agitator and the number of porous blades based on the working conditions and mechanical properties;

[0014] S200: Determine the final structural dimensions of the agitator and the total area of ​​the air outlet holes required on each porous blade according to the ventilation volume and gas velocity requirements;

[0015] S300: based on the total area of ​​the air outlet holes required on the porous blade, and in combination with experience, the number and diameter of the air outlet holes on the porous blade, the spacing between adjacent air outlet holes, and the initial value of the air inlet size are preliminarily determined;

[0016] S400: performing multiple iterations on the initial value obtained in step S300 according to the iterative relationship of the diameter of the air outlet, the distance from the air outlet to the air inlet, and the spacing between adjacent air outlets, to obtain the final values ​​of the number of air outlets, diameters, spacing between adjacent air outlets, and air inlet size on the porous blade;

[0017] S500: Based on the results of steps S200 and S400, a three-dimensional model of the agitator is preliminarily constructed and substituted into finite element software for simulation verification, and the distribution structure of the air outlet holes is determined according to the simulation results.

[0018] Preferably, in step S400, the iterative relationship between the diameter d of the air outlet, the distance L from the air outlet to the air inlet, and the spacing S between adjacent air outlets is:

[0019] ;

[0020] Among them, d i+1 and d i Respectively represent the diameters of two adjacent air outlets, d i+1The distance between the corresponding air outlet and the stirring shaft is greater than d i Corresponding vent hole, L i Indicates d i The corresponding distance from the air outlet to the air inlet.

[0021] Preferably, in step S400, the number of air outlets determined on the porous blade includes the number of groups of air outlets and the number of air outlets in each group; the specific iterative process of step S400 is: setting a limiting condition: in the flow data of each group of multiple air outlets, the flow difference between the maximum and minimum values ​​is within 5%; calculating the flow data of each group of multiple air outlets, if the calculated result does not meet the limiting condition, then reducing the diameter size of the air outlet corresponding to the maximum flow rate, and adaptively updating the diameter sizes of the remaining air outlets according to the iterative relationship; and / or, increasing the distance from the air outlet corresponding to the maximum flow rate to the air inlet, and adaptively updating the distance from the remaining air outlet to the air inlet according to the iterative relationship; performing a corresponding number of iterations until the flow data of each group of multiple air outlets meets the limiting condition.

[0022] Compared with the prior art, the beneficial effects of this application are:

[0023] Based on the structure of a traditional agitator, air outlet holes are opened on the blades to form porous blades. Air distribution is achieved by ventilating the porous blades, so that the function of the traditional air distributor can be integrated into the agitator, thereby simplifying the equipment structure of the mixing process and improving the efficiency of air dispersion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the agitator used for gas dispersion in this application.

[0025] Figure 2 For this application Figure 1 Schematic diagram of the local structure of the porous blade.

[0026] Figure 3 This is a schematic diagram of the state of the agitator when it is rotating and stirring in this application.

[0027] Figure 4 Schematic diagram of the design process of the agitator in this application.

[0028] Figure 5 This is a schematic diagram of the simulation of the agitator designed in this application.

[0029] In the figure: agitator 1, agitator shaft 11, air vent 110, porous blades 12, air outlet 120, air path 121, air inlet 122, air pipe 13, air inlet 130. DETAILED DESCRIPTION

[0030] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0031] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present application.

[0032] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0033] In this application, 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 connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] The terms "including" and "having" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0036] One aspect of the present application provides a stirrer 1 for dispersing gas, such as Figure 1 As shown, one of the preferred embodiments includes a stirring shaft 11 and a porous blade 12 installed on the stirring shaft 11. The stirring shaft 11 is rotatably installed in a tank body (not shown). The stirring shaft 11 is a hollow structure, that is, a vent hole 110 is provided at the center of the stirring shaft 11, and the upper end of the vent hole 110 can be connected to an external air source; the porous blade 12 is fixedly installed on the stirring shaft 11 and is internally connected. The specific number of the porous blades 12 can be selected according to the actual working conditions. A plurality of air outlets 120 are provided on the porous blade 12, and the air inlet end of the air outlet 120 can be connected to the air outlet 110 at the center of the stirring shaft 11, so that the air transported by the air source to the air outlet 110 can be passed through the air outlet 110 and then flow out of the tank body along the air outlet 120, so that during the process of the agitator 1 rotating and stirring, the porous blade 12 distributes air by rotating with the stirring shaft 11.

[0037] It can be understood that, based on the structure of a traditional agitator, the present application provides air outlet holes 120 on the blades to form porous blades 12, and air distribution is achieved by ventilating the porous blades 12, so that the function of the traditional air distributor can be integrated into the agitator 1, thereby simplifying the equipment structure of the existing mixing process and improving the efficiency of air dispersion.

[0038] Specifically, the traditional air distributor is mainly arranged at the bottom of the tank, and there is a certain distance between the air distributor and the traditional agitator. When the traditional air distributor and the traditional agitator are working, the air distributor can spray air upward to form bubbles that float upward; at this time, the traditional agitator can form a vortex field by stirring the fluid in the tank, and the vortex field may change the path of the bubbles floating upward, so that the bubbles are concentrated at a certain local position of the blades and dispersed, which will lead to a decrease in the air dispersion efficiency.

[0039] In this embodiment, the porous blade 12 is formed by opening an air outlet 120 on the traditional blade, so that the function of the traditional air distributor is integrated into the agitator 1. Therefore, during the normal operation of the agitator 1, it is only necessary to pass air into the air vent 110 of the agitator shaft 11, and the gas can enter the porous blade 12 along the air vent 110 and be discharged from the air outlet 120. Based on the technical solution of the present application, on the one hand, the gas to be dispersed has been arranged relatively evenly at various positions of the tank body through the distribution structure of the porous blade 12, so that each space area of ​​the tank body can be exposed to an equal amount of air; on the other hand, the distance between the gas to be dispersed and the porous blade 12 can be regarded as zero distance, that is, the gas can be dispersed by contacting the porous blade 12 after being discharged from the air outlet 120; and the vortex disturbance near the porous blade 12 is relatively large, which can quickly disperse the dispersed air to further improve the efficiency.

[0040] In this embodiment, Figure 3 As shown, the opening direction of the air outlet 120 is opposite to the rotation direction of the porous blade 12. In this way, the energy loss of the stirrer 1 can be reduced while the bubbles are dispersed.

[0041] It is understandable that Figure 3 For example, assuming that the stirring direction of the stirrer is counterclockwise, that is, Figure 3 The dotted arrow in the middle indicates the direction in which the air outlet holes 120 on the porous blade 12 are discharged in a clockwise direction, that is, Figure 3 The solid arrow in the middle indicates the direction. It should be known to those skilled in the art that, during the rotation of the agitator 1, the vortex disturbance generated by the porous blades 12 is located behind the rotation direction, so the outlet direction of the air outlet 120 is designed to be opposite to the rotation direction of the porous blades 12, which can ensure that the gas discharged from the air outlet 120 is instantly in contact with the vortex disturbance generated by the porous blades 12 and is broken up to form tiny bubbles. At the same time, the air outlet 120 discharges gas in the opposite direction of the rotation of the porous blades 12, which can provide assistance to the rotation of the porous blades 12, so as to reduce the driving force required for the normal stirring rotation of the agitator 1, thereby reducing energy loss and achieving cost savings.

[0042] In this embodiment, Figure 1 and Figure 2 As shown, the porous blade 12 is provided with at least one group of air outlet holes 120 along the axial direction of the stirring shaft 11. The multiple air outlet holes 120 of each group are arranged along the radial direction of the stirring shaft 11, and the diameters of the multiple air outlet holes 120 of each group increase from near to far according to the distance from the stirring shaft 11.

[0043] It can be understood that the size of the air outlet 120 is relatively small relative to the structural size of the porous blade 12, and it is often necessary to set up multiple air outlets 120; and in order to ensure that the air discharged from the air outlet 120 is relatively uniform, it is necessary to arrange these air outlets 120 in an array, that is, they can be divided into at least one column and at least one row along the axial and radial directions. Generally speaking, the air outlet 120 can form an array arrangement of multiple rows and columns; wherein the multiple columns of air outlets 120 in each row can be regarded as a group, so that multiple groups of air outlets 120 arranged at intervals in the axial direction can be obtained. The specific number of groups of air outlets 120 required to be arranged and the specific number of air outlets 120 required for each group can be designed according to actual needs, and the specific design process will be described in detail in the subsequent content.

[0044] It should be known that the air pressure entering the porous blade 12 from the vent hole 110 flows through the multiple air outlets 120 of each group in sequence, so the gas flow rate corresponding to the more backward the air outlet 120 is, the lower it is. If the diameters of the multiple air outlets 120 in each group are the same, the air volume of the later air outlets 120, that is, the air outlets 120 far away from the stirring shaft 11, may be less, thereby affecting the uniform dispersion effect of the gas. Therefore, in this embodiment, the diameter size can be changed according to the distance from the air outlet 120 to the stirring shaft 11, so as to ensure that the air volume discharged by the multiple air outlets 120 in each group is the same or similar.

[0045] It should be noted that the spacing between two adjacent air outlets 120 in each group can be kept consistent. However, from the above analysis results, it can be seen that the larger the diameter of the air outlet 120, the stronger the dispersion of the air flow that can be discharged, and the larger the dispersion area formed when the discharged gas is dispersed, which may cause it to overlap with the dispersion area formed by the adjacent air outlet 120, thereby affecting the dispersion effect of the bubbles. Therefore, for the spacing between two adjacent air outlets 120 in each group, it is preferred that it can be increased from near to far according to the distance to the stirring shaft 11. That is, the farther the air outlet 120 is from the stirring shaft 11, the larger the spacing between it and the previous adjacent air outlet 120.

[0046] In this embodiment, Figure 1 and Figure 2As shown, an axially extending air inlet 122 is provided on one side of the porous blade 12 close to the stirring shaft 11, and the multiple groups of air outlet holes 120 are connected to the air vents 110 of the stirring shaft 11 through the air inlet 122. Specifically, a plurality of air paths 121 corresponding to each group of air outlet holes 120 are provided in the porous blade 12, and one end of each air path 121 is connected to the air inlet 122, so that the air introduced from the stirring shaft 11 can flow to each air path 121 after entering the air inlet 122, until it is discharged from the air outlet holes 120 corresponding to each air path 121.

[0047] It is understandable that, based on the flow characteristics of the airflow, the exhaust performance of each air outlet 120 will be affected by the air inlet 122. Specifically, the spacing between the air outlets 120 can be set to S, and the distance between the air outlet 120 and the air inlet 122 can be set to L; except for the air outlet 120 closest to the air inlet 122, the diameter d of the remaining air outlets 120 is ∝ (S / L)^(1 / 5). The specific relationship between the diameter d of the air outlet 120, the spacing between the air outlets 120 is S, and the distance between the air outlet 120 and the air inlet 122 is L will be described in detail in the subsequent design method.

[0048] In this embodiment, Figure 1 As shown, the porous blades 12 and the stirring shaft 11 generally adopt a split structure, that is, the stirring shaft 11 and the porous blades 12 are detachably and tightly fixedly connected. In order to facilitate the installation between the porous blades 12 and the stirring shaft 11, a vent pipe 13 can be installed along the radial extension of the side of the stirring shaft 11; the porous blades 12 are connected to the stirring shaft 11 through the vent pipe 13. It should be noted that in order to ensure the stability of the exhaust volume of the air outlet holes 120, it is necessary to ensure that the total area of ​​all the air outlet holes 120 on the porous blades 12 is less than or equal to the cross-sectional area of ​​the air inlet hole 130 set in the center of the vent pipe 13.

[0049] In this embodiment, it can be seen from the above content that the porous blade 12 is provided with an air path 121, an air inlet 122 and a plurality of air outlets 120, which will lead to a complicated internal structure of the porous blade 12, and the traditional casting method is basically unable to realize the production of the porous blade 12. Therefore, in this embodiment, the porous blade 12 can be produced by metal powder 3D printing technology. The metal powder material used when the porous blade 12 is produced by metal powder 3D printing technology can be selected according to the specific working conditions required by the porous blade 12, for example, stainless steel powder can be used.

[0050] Another aspect of the present application provides a design method of the above-mentioned agitator 1 for dispersing gas, such as Figure 4 and Figure 5 As shown, one of the preferred embodiments includes the following design steps:

[0051] S100: Preliminarily determine the structural dimensions of the agitator 1 and the number of porous blades 12 according to the working conditions and mechanical properties.

[0052] S200: Determine the final structural dimensions of the agitator 1 and the total area of ​​the air outlet holes 120 required on each porous blade 12 according to the ventilation volume and gas velocity requirements.

[0053] S300: Based on the total area of ​​the air outlet holes 120 required on the porous blade 12 and combined with experience, the number and diameter of the air outlet holes 120 on the porous blade 12, the distance between adjacent air outlet holes 120 and the initial value of the size of the air inlet 122 are preliminarily determined.

[0054] S400: The initial value obtained in step S300 is iterated multiple times according to the iterative relationship of the diameter of the air outlet holes 120, the distance from the air outlet holes 120 to the air inlet 122, and the spacing between adjacent air outlet holes 120 to obtain the final values ​​of the number of air outlet holes 120, the diameter, the spacing between adjacent air outlet holes 120, and the size of the air inlet 122 on the porous blade 12.

[0055] S500: Based on the results of steps S200 and S400, a three-dimensional model of the agitator 1 is preliminarily constructed and put into finite element software for simulation verification, and the distribution structure of the air outlet holes 120 is determined according to the simulation results.

[0056] Specifically, when performing step S100, the overall structural size, rotation speed and required number of porous blades 12 of the agitator 1 can be determined according to the working conditions required for the agitator 1; and then the shaft diameter and thickness of the agitator shaft 11 can be preliminarily given according to the mechanical properties of the selected material.

[0057] It should be noted that the cross-sectional dimensions of the stirring shaft 11 are mainly determined based on the bending moment and torque that it needs to withstand during the stirring process, and the size of the central vent hole 110 may not meet the ventilation requirements. Therefore, in step S200, the size of the vent hole 110 can be designed based on the ventilation volume and gas velocity required for the stirring condition. After the size of the vent hole 110 is obtained, the thickness and outer cross-sectional diameter of the stirring shaft 11 can be reversed by combining the bending and torsional performance calculation formula, that is, the final structural dimensions of the stirring shaft 11 can be obtained.

[0058] At the same time, based on the number of porous blades 12 and the requirements of ventilation volume and ventilation speed, the average ventilation volume and ventilation speed required for each porous blade 12 can be obtained, and then the structural size of the air inlet 122 inside the porous blade 12 and the total area of ​​all the air outlet holes 120 on the porous blade 12 can be obtained in combination with conventional design means in the art. That is, after the design of steps S100 and S200, the design of the overall outline size of the agitator 1 can be completed; the design of the size and arrangement of the air outlet holes 120 has the greatest impact on the gas dispersion effect in this embodiment, which will be described in detail below.

[0059] Specifically, when performing step S300, in order to facilitate the subsequent iterative optimization calculation, it is necessary to preliminarily determine the number of air outlets 120, the diameter, the spacing between adjacent air outlets 120, and the initial values ​​of the size of the air inlet 122 based on the known total area of ​​the air outlets 120. These initial values ​​can be given based on the experience of those skilled in the art. For example, the position of the air inlet 122 and the distance between the air inlet 122 and the nearest air outlet 120 in each group can be determined, so that the position of the air inlet 122 and the first air outlet 120 in each group can be determined, and then the spacing between the first air outlet 120 and the second air outlet 120 in each group can be given, and then the spacing between each group of subsequent adjacent air outlets 120 can be determined by equal spacing or equal proportional increase. In this way, the number of all air outlets 120 and the local arrangement can be calculated in combination with the length and width of the porous blade 12. Finally, the diameter size of the first air outlet 120 in each group can be given, and each group of subsequent air outlets 120 can be calculated by fixed value increase or equal proportional increase. It should be noted that the plurality of air outlet holes 120 in each group are arranged from near to far from the stirring shaft 11 , that is, the first air outlet hole 120 is closest to the stirring shaft 11 .

[0060] After obtaining the initial values ​​of the structure and distribution size data of all the pores 120 on the porous blade 12, the given initial values ​​can be iteratively optimized. In order to ensure the accuracy of the iterative results, it is necessary to select a suitable iterative calculation formula. It should be known to those skilled in the art that the pressure loss of the fluid in the pipeline is often calculated using the Hezen-Williams formula, and the specific calculation formula is as follows:

[0061] h = [10.66 × L × Q 1.852 ] / [C 1.852 ×d 4.87 ].

[0062] Wherein, h represents the head loss, L represents the pipe length, that is, the distance from the air outlet 120 to the air inlet 122 in this embodiment; Q represents the average flow rate, and C represents a constant, which is related to the surface roughness of the pipe.

[0063] From the above content, it can be known that for each group of multiple outlet holes 120, in order to ensure uniform dispersion of bubbles, it is necessary to ensure that the multiple outlet holes 120 in each group have nearly the same flow rate. Then any two adjacent outlet holes 120 can be selected, and the corresponding diameters of the two are d i+1 and d i ; then the diameter d i+1 and d i The corresponding head loss h i+1 and h i They are:

[0064] h i =[10.66×L i ×Q 1.852 ] / [C 1.852 ×d i 4.87 ].

[0065] h i+1 =[10.66×(L i +S)×Q 1.852 ] / [C 1.852 ×d 4.87 ].

[0066] Where Li represents the diameter d i The distance from the corresponding air outlet 120 to the air inlet 122; S represents the diameter d i+1 and d i The distance between two corresponding air outlet holes 120 .

[0067] To obtain the same flow rate, the same head loss is required, that is, h i = h i+1 , the corresponding iterative relationship can be obtained by combining:

[0068] .

[0069] In a rough calculation, we can take ; That is, the diameter d of the air outlet 120 is proportional to (S / L)^(1 / 5).

[0070] Based on the above iterative relationship, the diameter size of the second air outlet 120 and the diameter size and spacing size parameters of all subsequent air outlets 120 can be calculated according to the given diameter and distribution parameters of each group of first air outlets 120. For ease of understanding, the following will be explained through specific examples.

[0071] Specifically, Figure 2As shown, assuming that the number of each group of air outlet holes 120 is initially determined to be five, the distance between the first air outlet hole 120 and the air inlet 122 is L0, the spacing between the first air outlet hole 120 and the second air outlet hole 120 is S1, the spacing between the second air outlet hole 120 and the third air outlet hole 120 is S2, the spacing between the third air outlet hole 120 and the fourth air outlet hole 120 is S3, and the spacing between the fourth air outlet hole 120 and the fifth air outlet hole 120 is S4. Then, from the given diameter d1 of the first air outlet hole 120, the diameter d2 of the second air outlet hole 120, the diameter d3 of the third air outlet hole 120, the diameter d4 of the fourth air outlet hole 120, and the diameter d5 of the fifth air outlet hole 120 can be calculated as follows:

[0072] .

[0073] .

[0074] .

[0075] .

[0076] After calculating the diameter size of each group of multiple air outlet holes 120, the actual flow rate corresponding to each air outlet hole 120 can be calculated according to calculation formulas such as the Bernoulli equation, and then the actual flow rates of the multiple air outlet holes 120 in each group can be compared to ensure that the actual flow rates of all the air outlet holes 120 in each group are consistent.

[0077] Generally speaking, for the flow rates corresponding to each group of multiple air outlets 120, the flow rate difference between the maximum and minimum values ​​is within 5% and is considered to be consistent; and the flow rate difference between the maximum and minimum values ​​of the flow data of each group of multiple air outlets 120 is within 5% as a limiting condition for iteration.

[0078] The specific iteration process in step S400 is as follows: Calculate whether the flow data of each group of multiple air outlets 120 meets the flow difference between the maximum value and the minimum value within 5%. If the calculated result does not meet the limiting condition that the flow difference is within 5%, it is necessary to reduce the diameter size of the air outlet 120 corresponding to the maximum flow rate, and the diameter size of the remaining air outlets 120 needs to be adaptively updated according to the above-mentioned iterative relationship. Alternatively, the distance from the air outlet 120 corresponding to the maximum flow rate to the air inlet 122 can also be changed, and the distance from the remaining air outlet 120 to the air inlet 122 needs to be adaptively updated according to the above-mentioned iterative relationship. It is also possible to change the diameter size of the air outlet 120 corresponding to the maximum flow rate and the distance size from the air inlet 122 at the same time, and adaptively update the relevant parameters of the remaining air outlets 120. Finally, after the corresponding number of iterations, the final values ​​of the number of air outlets 120 on the porous blade 12, the diameter, the spacing between adjacent air outlets 120, and the size of the air inlet 122 can be obtained.

[0079] It is understandable that the above-mentioned structural design process is a process of theoretical calculation. In order to verify the accuracy of the theoretical calculation results, three-dimensional modeling can be performed based on the structural dimensions of the agitator 1 obtained by theoretical calculation, and then the established three-dimensional model can be imported into finite element software, such as ANSYS software, for flow field simulation analysis. The accuracy of the theoretical calculation is verified based on the simulation results. At the same time, the simulation results can also be used to determine whether the spacing arrangement dimensions of multiple groups of air outlets 120 are reasonable. If the theoretical calculation results are basically consistent with the simulation results, the agitator 1 can be produced and processed based on the calculated structural parameters; if there is a deviation between the theoretical calculation results and the simulation results, the theoretical calculation results can be corrected based on the deviation until the theoretical calculation results and the simulation results are consistent. Among them, the spacing size between two adjacent groups of air outlets 120 is based on the simulation results with the best flow field distribution performance.

[0080] For ease of understanding, the above design process will be described in detail below through specific parameters. Since the design process of the contour structure dimensions of the stirring shaft 11 and the porous blades 12 is a conventional design in the art, it will not be described in detail here; the following is a specific description of the design process of the distribution structure dimensions of the air outlet holes 120. In order to further simplify the description process, the spacing between any two adjacent air outlet holes 120 in each group is equal as an example for explanation.

[0081] like Figure 5As shown, the number of air outlet holes 120 in a group is set to three, and the diameters of the air outlet holes 120 are d1, d2 and d3 in the order of arrangement, and the corresponding spacings are S1 and S2. Given the initial value of the diameter d1 is 18 mm, the distance L0 from the first air outlet hole 120 to the air inlet 122 is 170 mm, and S1=S2=55 mm.

[0082] According to the aforementioned iterative relationship, we round off and calculate to get d2=19mm, d3=20mm.

[0083] Assuming that the air velocity from the vent hole 110 to the air inlet 122 is 10 mm / s, the outlet flow rate corresponding to the first air outlet 120 can be calculated according to the Bernoulli equation to be 3334967 mm 3 / s, the outlet flow rate of the second outlet hole 120 is 3316122mm 3 / s, the outlet flow rate corresponding to the third outlet hole 120 is 3093196 mm 3 / s. Among them, the outlet flow rate corresponding to the third outlet hole 120 is the smallest, and the outlet flow rate corresponding to the first outlet hole 120 is the largest. The flow rate difference between the two is 7.82%, which is greater than the 5% given by the limiting condition. Therefore, the diameter parameters of d1=18mm, d2=19mm and d3=20mm do not meet the requirements. It is necessary to reduce the values ​​of d1 and d2 and increase the value of d3 according to the flow size distribution.

[0084] You can reset d1 to 14 mm and correct =17.1mm, =20.62mm. Substituting the recalculated diameter value into the Bernoulli equation, it can be calculated that the outlet flow rate corresponding to the first outlet hole 120 is 2560322mm 3 / s, the outlet flow rate corresponding to the second outlet hole 120 is 2672186mm 3 / s, the outlet flow rate corresponding to the third outlet hole 120 is 2607517 mm 3 / s. Among them, the outlet flow rate corresponding to the first air outlet 120 is the smallest, and the outlet flow rate corresponding to the second air outlet 120 is the largest. The flow rate difference between the two is 4.369%, which meets the 5% given by the limiting condition. Therefore, it can be obtained that the diameters of the three air outlets 120 are 14mm, 17.1mm and 20.62mm respectively. Based on the diameter of the air outlet 120, the diameter of the air inlet 130 at the center of the ventilation pipe 13 can be inferred.

[0085] Finally, a three-dimensional model is constructed based on the obtained structural dimension data of the air outlet 120 for simulation verification. Figure 5As shown; according to the simulation results, it can be seen that the outlet flow rates of the three air outlets 120 are consistent, that is, the simulation results are consistent with the results of theoretical calculations.

[0086] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A stirrer for dispersing gas, characterized in that: It comprises a stirring shaft and a porous blade mounted on the stirring shaft; the porous blade is provided with a plurality of air outlet holes, and the air inlet end of the air outlet hole is connected with the air vent hole provided at the center of the stirring shaft, so that air passes through the air vent hole into the porous blade and flows out along the air outlet hole, and then the air is distributed in the process that the porous blade rotates with the stirring shaft; The porous blade is provided with at least one group of the outlet holes along the axial direction of the stirring shaft, and the multiple outlet holes in each group are arranged along the radial direction of the stirring shaft, and the diameters of the multiple outlet holes in each group increase in sequence from near to far according to the distance from the stirring shaft; The distance between two adjacent air outlet holes in each group increases from near to far according to the distance to the stirring shaft; An axially extending air inlet is provided on one side of the porous blade close to the stirring shaft, and a plurality of groups of air outlet holes are connected with the air vents of the stirring shaft through the air inlet; Assume that the spacing between the air outlets is S, and the distance between the air outlets and the air inlet is L; except for the air outlet closest to the air inlet, the diameters of the remaining air outlets d∝(S / L)^(1 / 5).

2. The agitator for dispersing gas according to claim 1, characterized in that: The opening direction of the air outlet is opposite to the rotation direction of the porous blades.

3. The agitator for dispersing gas according to claim 1 or 2, characterized in that: A ventilation pipe is radially extended from the side of the stirring shaft, and the porous blades are connected to the stirring shaft through the ventilation pipe; the total area of ​​all the air outlet holes on the porous blades is less than or equal to the cross-sectional area of ​​the air inlet hole arranged at the center of the ventilation pipe.

4. The agitator for dispersing gas according to claim 1, characterized in that: The porous blades are manufactured using metal powder 3D printing technology.

5. A method for designing a stirrer for dispersing gas according to any one of claims 1 to 4, characterized in that: The design steps include: S100: Preliminary determination of the structural dimensions of the agitator and the number of porous blades based on the working conditions and mechanical properties; S200: Determine the final structural dimensions of the agitator and the total area of ​​the air outlet holes required on each porous blade according to the ventilation volume and gas velocity requirements; S3 00: Based on the total area of ​​the outlet holes required on the porous blade, the number of outlet holes, diameter, spacing between adjacent outlet holes and initial values ​​of the air inlet size on the porous blade are initially determined in combination with experience; S400: performing multiple iterations on the initial value obtained in step S300 according to the iterative relationship of the diameter of the air outlet, the distance from the air outlet to the air inlet, and the spacing between adjacent air outlets, to obtain the final values ​​of the number of air outlets, diameters, spacing between adjacent air outlets, and air inlet size on the porous blade; S500: Based on the results of steps S200 and S400, a three-dimensional model of the agitator is preliminarily constructed and substituted into finite element software for simulation verification, and the distribution structure of the air outlet holes is determined according to the simulation results.

6. The method for designing a stirrer for dispersing gas according to claim 5, characterized in that: In step S400, the iterative relationship between the diameter d of the air outlet, the distance L from the air outlet to the air inlet, and the spacing S between adjacent air outlets is: ； Among them, d i+1 and d i Respectively represent the diameters of two adjacent air outlets, d i+1 The distance between the corresponding air outlet and the stirring shaft is greater than d i Corresponding vent hole, L i Indicates d i The corresponding distance from the air outlet to the air inlet.

7. The method for designing a stirrer for dispersing gas according to claim 6, characterized in that: In step S400, the number of air outlet holes determined on the porous blade includes the number of groups of air outlet holes and the number of air outlet holes in each group; The specific iterative process of step S400 is: Set limiting conditions: In the flow data of each group of multiple outlets, the difference between the maximum and minimum flow rates is within 5%; Calculate the flow data of each group of multiple outlet holes. If the calculated result does not meet the limited conditions, reduce the diameter of the outlet hole corresponding to the maximum flow rate, and adaptively update the diameters of the remaining outlet holes according to the iterative relationship. And / or, the distance from the air outlet corresponding to the maximum flow rate to the air inlet is increased, and the distances from the remaining air outlets to the air inlet are adaptively updated according to the iterative relationship; a corresponding number of iterations are performed until the flow data of each group of multiple air outlets meets the specified conditions.

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