Stirring paddle and cell culture bioreactor

Abstract

The invention discloses a stirring paddle and a cell culture bioreactor, and relates to the technical field of cell culture.The stirring paddle and the cell culture bioreactor comprise a stirring shaft, a plurality of first paddles, two annular discs and a plurality of second paddles, the first paddles are installed on the stirring shaft and arranged at intervals in the circumferential direction of the stirring shaft, and the annular discs are installed on the stirring shaft; the two circular ring discs are arranged at the two ends of the stirring shaft respectively and are arranged in parallel in the axial direction of the stirring shaft, and inner rings of the circular ring discs are connected with the side ends, deviating from the stirring shaft, of the first paddles so as to drive the circular ring discs to rotate around the axis of the stirring shaft when the first paddles rotate; and the plurality of second paddles are mounted between the two annular discs. The stirring efficiency and the flow field uniformity are improved, and the overall performance and the production efficiency of the bioreactor are further improved while the low shearing force is maintained.

Description

Technical Field

[0001] This invention relates to the field of cell culture technology, and in particular to a stirring impeller and a cell culture bioreactor. Background Technology

[0002] Cell culture bioreactors are core equipment that simulates the physiological environment in vivo (temperature, pH, dissolved oxygen, etc.) to achieve large-scale cell proliferation and production of bioactive substances (such as antibodies and vaccines) in vitro. Their core value lies in improving cell density and product yield through precise control of culture conditions, and they are widely used in biopharmaceutical, cell therapy, and scientific research fields.

[0003] Traditional stirring systems generally suffer from uneven flow field distribution, making it difficult to achieve efficient axial and radial fluid motion simultaneously. This limitation leads to the formation of mixing dead zones inside the culture medium, causing an imbalance in the distribution of nutrients and metabolites, which in turn affects the uniformity of cell growth. In addition, the high shear force generated by the conventional stirring paddle structure during rotation is concentrated in a region that can easily cause mechanical damage to sensitive cells, reduce cell survival rate, and interfere with product synthesis efficiency. Summary of the Invention

[0004] The main objective of this invention is to propose a stirring impeller and cell culture bioreactor that aims to improve flow field distribution, achieve efficient axial and radial fluid motion, reduce mixing dead zones, and reduce shear force damage to cells.

[0005] To achieve the above objectives, the present invention provides a stirring impeller and a cell culture bioreactor, comprising: Stirring shaft; Multiple first blades are mounted on the stirring shaft and spaced apart circumferentially along the stirring shaft. Two annular disks are respectively disposed at both ends of the stirring shaft and arranged parallel to the axial direction of the stirring shaft. The inner ring of each annular disk is connected to the side of the first impeller facing away from the stirring shaft, so that when the first impeller rotates, it drives the annular disk to rotate around the axis of the stirring shaft; and Multiple second blades are installed between two annular disks.

[0006] Preferably, the first impeller is inclined to the plane of rotation of the stirring shaft axis, so that axial flow and radial flow are generated simultaneously when the first impeller rotates.

[0007] Preferably, the end of the first blade away from the stirring shaft is arc-shaped.

[0008] Preferably, the first blade has at least four blades.

[0009] Preferably, the center of the stirring shaft in the radial direction is hollowed out.

[0010] Preferably, the second blade extends radially along the stirring shaft, and the second blade is arranged in an arc shape radially along the stirring shaft.

[0011] Preferably, a connecting block is provided between two adjacent second blades, the connecting block being located between the two annular disks and arranged at intervals along the circumference of the stirring shaft.

[0012] Preferably, a plurality of arc-shaped plates are provided between the inner rings of the two annular disks, and each arc-shaped plate is spaced apart circumferentially along the stirring shaft.

[0013] Preferably, a connecting block is provided between two adjacent second blades; The arc-shaped plate is provided with two connecting blocks and a second impeller on the side away from the stirring shaft.

[0014] Furthermore, to achieve the above objectives, the present invention also proposes a cell culture bioreactor, comprising: container; A drive unit is mounted on the container; The stirring paddle, driven and connected to the driving device, includes a stirring shaft, multiple first blades, two annular disks, and multiple second blades. The multiple first blades are mounted on the stirring shaft and spaced apart circumferentially along the stirring shaft. The two annular disks are respectively located at both ends of the stirring shaft and are arranged parallel to each other along the axial direction of the stirring shaft. The inner ring of each annular disk is connected to the side of the first blade facing away from the stirring shaft, so that when the first blade rotates, it drives the annular disk to rotate around the axis of the stirring shaft. The multiple second blades are mounted between the two annular disks.

[0015] In the technical solution provided by this invention, a plurality of first impellers are mounted on the stirring shaft and spaced apart circumferentially along the stirring shaft. Two annular disks are respectively disposed at both ends of the stirring shaft and arranged parallel to each other along the axial direction of the stirring shaft. The inner ring of the annular disk is connected to the side of the first impeller facing away from the stirring shaft, so that when the first impeller rotates, it drives the annular disk to rotate around the axis of the stirring shaft. A plurality of second impellers are mounted between the two annular disks, which improves the stirring efficiency and flow field uniformity. Moreover, while maintaining low shear force, it improves the overall performance and production efficiency of the bioreactor. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 A three-dimensional schematic diagram of an embodiment of the stirring impeller and cell culture bioreactor provided by the present invention; Figure 2 for Figure 1 A schematic diagram of the structure of the second blade in the middle; Figure 3 for Figure 1 Velocity contour plot of the stirring impeller; Figure 4 for Figure 1 Vector diagram of the speed of the stirring paddle; Figure 5 for Figure 1 Shear rate contour plot of the agitator.

[0018] Explanation of icon numbers: 100. Stirring paddle and cell culture bioreactor; 1. First impeller blade; 2. Circular disc; 3. Second impeller blade; 31. Arc plate; 32. Connecting block.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] This invention provides a stirring impeller and a cell culture bioreactor 100. Figures 1 to 5 This is an embodiment of the stirring impeller and cell culture bioreactor 100 provided by the present invention.

[0024] In traditional cell culture bioreactors, the hydrodynamic characteristics of the stirring system have a decisive impact on the cell growth environment. Existing impeller designs struggle to simultaneously achieve adequate mixing and a low-shear stress environment, leading to uneven distribution of nutrients and metabolites in the culture medium. Furthermore, the turbulent shear forces generated during rotation cause cell membrane damage and apoptosis. This problem directly limits the increase in cell culture density and the stable synthesis efficiency of target products.

[0025] Please refer to the following: Figures 1 to 2 The stirring impeller and cell culture bioreactor 100 includes a stirring shaft, a plurality of first impeller blades 1, two annular disks 2, and a plurality of second impeller blades 3. The plurality of first impeller blades 1 are mounted on the stirring shaft and spaced apart circumferentially along the stirring shaft. The two annular disks 2 are respectively disposed at both ends of the stirring shaft and arranged parallel to each other along the axial direction of the stirring shaft. The inner ring of the annular disk 2 is connected to the side of the first impeller 1 facing away from the stirring shaft, so that when the first impeller 1 rotates, it drives the annular disk 2 to rotate around the axis of the stirring shaft. The plurality of second impeller blades 3 are mounted between the two annular disks 2.

[0026] The first impeller 1 can be fixed to the stirring shaft by welding, bolting, or snap-fit ​​connection. In one implementation, the first impeller 1 can be pre-formed and then integrally connected to the stirring shaft by machining.

[0027] The inner ring of the annular disk 2 can be directly welded to the outer edge of the first impeller 1 or connected by bolts. In another implementation, a connector can be provided at the outer end of the first impeller 1, which is then fixed to the inner ring of the annular disk 2. When the first impeller 1 rotates, the annular disk 2 is driven to rotate synchronously around the stirring shaft axis through this rigid connection. The thickness and diameter of the annular disk 2 can be designed according to the overall size and strength requirements of the stirring impeller to ensure that it maintains structural stability during high-speed rotation.

[0028] The second blade 3 can be directly welded between the two annular disks 2 to form an integral structure. In another implementation, the second blade 3 can be designed as a detachable modular unit, connected to the annular disk 2 by bolts or other fasteners, allowing users to easily adjust the configuration of the second blade 3 according to different stirring requirements. The shape and size of the second blade 3 can be the same as or different from the first blade 1 to achieve specific flow field effects. For example, the second blade 3 can be designed as a flat plate, arc, or spiral to generate different shear forces or fluid circulation patterns.

[0029] The agitator generates the main macroscopic flow field through the first blade 1, ensuring overall fluid circulation, while the second blade 3 provides additional microscopic mixing and shearing between the annular disks 2, effectively eliminating local concentration gradients. This stratified and synergistic agitation mechanism allows for a more uniform distribution of nutrients, oxygen, and cells in the culture medium, thus providing a superior environment for healthy cell growth and high-density culture.

[0030] Therefore, in the technical solution provided by the present invention, a plurality of first impellers 1 are installed on the stirring shaft and spaced apart circumferentially along the stirring shaft. Two annular disks 2 are respectively disposed at both ends of the stirring shaft and arranged parallel to each other along the axial direction of the stirring shaft. The inner ring of the annular disk 2 is connected to the side of the first impeller 1 away from the stirring shaft, so that when the first impeller 1 rotates, it drives the annular disk 2 to rotate around the axis of the stirring shaft. A plurality of second impellers 3 are installed between the two annular disks 2, which improves the stirring efficiency and flow field uniformity. Moreover, while maintaining low shear force, it improves the overall performance and production efficiency of the bioreactor.

[0031] In an embodiment of the present invention, the first impeller 1 is inclined to the plane of rotation of the stirring shaft axis, and when the first impeller 1 rotates, both axial flow and radial flow are generated simultaneously.

[0032] The first blade 1 is inclined to the plane of rotation of the stirring shaft axis. This means that the blade surface of the first blade 1 or the whole blade forms a non-zero angle with respect to the axial direction of the stirring shaft or the plane of its rotation trajectory. The inclined setting allows the blade to generate a component force pointing axially and radially in addition to the tangential thrust when rotating. The inclined setting can be implemented in various ways. For example, the blade of the first blade 1 can be designed to have a certain helical angle, or the entire blade can have a fixed inclined angle with respect to the radial direction of the stirring shaft.

[0033] Furthermore, the end of the first blade 1 furthest from the stirring shaft is arc-shaped.

[0034] An arc shape refers to a smooth curve transition at the end, rather than a sharp corner or a straight edge. An arc shape can be achieved in a variety of ways. For example, during the manufacturing process, CNC machining technology can be used to mill or grind the blade edge to form a preset arc radius; or, during mold design, the end can be designed as an arc shape and obtained in one step through molding processes such as injection molding or casting.

[0035] Furthermore, the first blade 1 has at least four blades.

[0036] The number of first impeller blades 1 installed on the stirring shaft is no less than four, ensuring that the stirring blades can provide sufficient shear and thrust when rotating to overcome the viscous resistance of the fluid and establish an effective flow field within the stirring area. When there are four blades, one can be placed every 90 degrees; when there are six blades, one can be placed every 60 degrees. In addition, the first impeller blades 1 can also be non-uniformly distributed along the circumferential direction of the stirring shaft according to specific stirring requirements, so as to produce a stronger stirring effect in a specific area.

[0037] In an embodiment of the present invention, the center of the stirring shaft is hollowed out radially.

[0038] A hollowed-out design refers to the formation of one or more internal spaces in the radially central region of the stirring shaft, allowing material to be removed from that area, thus creating a hollow or partially hollow structure. The hollowed-out design can manifest as a central hole extending through the entire axial length of the stirring shaft, such as a cylindrical or polygonal cavity. Alternatively, the hollowed-out design can be non-through, for example, forming multiple independent blind holes or chambers within the stirring shaft, which can be distributed axially or radially. In some embodiments, the radially central portion of the stirring shaft can also be hollowed out using a mesh-like, honeycomb-like, or other porous structure to reduce weight while maintaining sufficient structural strength and rigidity.

[0039] For example, after the impeller is fitted with a stirring shaft, there is a 5-15mm gap between the impeller and the stirring shaft. During the rotation of the impeller, the impeller pushes the fluid to rotate, and the gap creates a turbulent flow field inside the impeller, reducing the dead zone in the flow field inside the impeller; in addition, it also helps to enhance axial flow and increase the strength of upward lifting of fluid.

[0040] When precise control of fluid movement is required or high-viscosity media are being processed, problems such as uneven mixing or fluid stagnation in local areas may occur. In an embodiment of the present invention, the second blade 3 extends radially along the stirring shaft, and the second blade 3 is arranged in an arc shape radially along the stirring shaft.

[0041] The main body of the second blade 3 or its main working surface extends radially outward from the center of the stirring shaft, ensuring that the second blade 3 can cover and effectively act on the fluid within the radial range between the two annular disks 2, thereby expanding the effective area of ​​the stirring action. For example, the second blade 3 can extend radially from the inner edge to the outer edge of the annular disk 2, and its radial length can cover most of the radial distance between the annular disks 2. Alternatively, the second blade 3 can be composed of multiple independent blades, each blade being approximately perpendicular to the stirring shaft in its long axis direction and extending radially outward. The arc design allows the second blade 3 to interact more effectively with the fluid when rotating, producing specific hydrodynamic effects. For example, the arc can be designed to bend in the direction of rotation of the stirring shaft to better "scoop up" or "push" the fluid, generating a stronger tangential flow. Alternatively, the arc can be designed to be an arc opposite to the direction of rotation of the stirring shaft to generate a certain resistance or guide the fluid to flow axially. The arc can be a uniform arc or a gradually changing non-uniform curve to adapt to different fluid characteristics and mixing requirements.

[0042] When stirring or processing high-viscosity fluids at high intensity, relying solely on the connection between the two ends of the second blade 3 and the annular disk 2 may cause the second blade 3 to undergo large deformation or vibration when subjected to force. In order to ensure stirring efficiency and equipment stability, in an embodiment of the present invention, a connecting block 32 is provided between two adjacent second blades 3. The connecting block 32 is located between the two annular disks 2 and is arranged at intervals along the circumference of the stirring shaft.

[0043] The connecting block 32 can be implemented in various forms. For example, it can be a solid rod-shaped, plate-shaped, or irregularly shaped structure, or a lightweight structure with reinforcing ribs. Its material can be the same as the blade, such as stainless steel or titanium alloy, or it can be a composite material with higher strength or corrosion resistance. It can effectively provide support within the axial span of the second blade 3. For example, one connecting block 32 can be set between every two adjacent second blades 3, or multiple connecting blocks 32 can be set between adjacent second blades 3 according to the length and stress of the second blade 3 to provide denser support.

[0044] Multiple arc-shaped plates 31 are provided between the inner rings of the two annular disks 2, and each arc-shaped plate 31 is spaced apart along the circumference of the stirring shaft.

[0045] The arc-shaped plate 31 is a plate-like structure with a certain curvature, designed to interact with the fluid to change its flow direction, velocity, or generate eddies. The arc-shaped plate 31 can be made of various materials, such as stainless steel, polypropylene, and polytetrafluoroethylene, with the specific choice determined by the properties of the fluid being stirred and the working environment. Its shape can be a simple arc segment or a complex curved surface optimized by fluid dynamics to achieve specific flow field control effects. The spacing ensures that the fluid can flow freely between the arc-shaped plates 31 while being effectively guided and disturbed by them. The number and spacing angle of the arc-shaped plates 31 can be adjusted according to the size of the impeller, the characteristics of the stirring medium, and the required stirring intensity. For example, they can be uniformly distributed or non-uniformly distributed based on flow field analysis results to optimize the stirring effect.

[0046] A connecting block 32 is provided between two adjacent second blades 3; two connecting blocks 32 and one second blade 3 are provided on the side of the arc plate 31 away from the stirring shaft.

[0047] The connecting block 32 can be implemented in various forms. For example, it can be a solid columnar or plate-like structure, fixed to adjacent components by welding, bolting, or integral molding; or it can be a reinforcing rib with a specific cross-sectional shape (such as an airfoil or streamlined shape), designed to provide structural support while optimizing fluid resistance or guiding flow. Two connecting blocks 32 and a second impeller 3 are arranged on the side of the arc-shaped plate 31 away from the stirring shaft. This arrangement describes a specific spatial relationship between the connecting blocks 32, the arc-shaped plate 31, and the second impeller 3. The side of the arc-shaped plate 31 away from the stirring shaft is its outer edge region, which typically bears a large fluid force. The arrangement of two connecting blocks 32 and a second impeller 3 in this region means that these components are spatially closely related, forming a local structural unit. This arrangement ensures that the second impeller 3 is effectively supported and fixed on the outside of the arc-shaped plate 31, while the connecting blocks 32 further enhance the structural strength and stability of this region and may influence the flow path of the fluid between the arc-shaped plate 31 and the second impeller 3.

[0048] Furthermore, this invention also proposes a cell culture bioreactor, including a container, a drive device, and a stirring paddle. The drive device is mounted on the container, and the stirring paddle is drivenly connected to the drive device. The stirring paddle includes a plurality of first blades 1 mounted on a stirring shaft and spaced apart circumferentially along the stirring shaft. Two annular disks 2 are respectively disposed at both ends of the stirring shaft and arranged parallel to each other along the axial direction of the stirring shaft. The inner ring of the annular disk 2 is connected to the side of the first blade 1 facing away from the stirring shaft, so that when the first blade 1 rotates, it drives the annular disk 2 to rotate around the stirring shaft axis. A plurality of second blades 3 are mounted between the two annular disks 2.

[0049] To assess the physical properties of low-shear-tolerant cells in three working volumes of 500ml, CFD simulations of the stirring process were performed. Table 1 shows a comparison of shear rates, as follows:

[0050] Table 2 contains the power dissipation table, as follows:

[0051] As shown in the two tables above, at the same absolute speed, there is an asymmetric difference in shear rates between the forward and reverse directions. At low speeds (16 / 24 rpm), the maximum shear rate in the reverse direction is slightly higher than that in the forward direction. At high speeds (55 rpm), the average shear rate in the impeller region in the reverse direction is higher than that in the forward direction, while the average shear rate in the tank is the opposite. TED is strongly positively correlated with the absolute speed, and its growth rate increases significantly with increasing speed. At the same speed, the average TED in the impeller region is significantly higher than that in the tank, with a ratio ranging from 2.0 to 3.1. This indicates that the impeller region is the core area for turbulent energy input, while the energy dissipation in the tank region is relatively gentle. At the same absolute speed, the average TED in the impeller region in the forward direction is generally higher than that in the reverse direction, which complements the directional effect of the shear rate.

[0052] Please see Figures 3 to 5 Whether stirred counterclockwise or clockwise, the entire fluid moves in a top-to-bottom upward tumbling pattern, counteracting the effect of gravity that causes cells to sink to the bottom. This is closer to the microcirculation of the human body and provides a more biomimetic microenvironment for cell culture.

[0053] The fluid flows out from the outer diameter of the impeller along the tangential direction of the impeller's rotation. During the stirring process, due to the obstruction of the rectangular structure, the fluid cannot flow from the outer diameter to the inner region of the impeller. It can only flow into the inner region of the impeller from the gap between the impeller and the rectangular structure below the red circle. However, due to its upward flow, kinetic energy is converted into potential energy, thus reducing the flow velocity and minimizing the dead zone of the stirring. At speeds of ±32 rpm, it can provide a good vertical flow field and good fluid turbulence, which is beneficial for liquid / gas mass transfer and reduces bottom settling.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A stirring paddle, characterized in that, include: Stirring shaft; Multiple first blades are mounted on the stirring shaft and spaced apart circumferentially along the stirring shaft. Two annular disks are respectively disposed at both ends of the stirring shaft and arranged parallel to the axial direction of the stirring shaft. The inner ring of each annular disk is connected to the side of the first impeller facing away from the stirring shaft, so that when the first impeller rotates, it drives the annular disk to rotate around the axis of the stirring shaft; and Multiple second blades are installed between two annular disks.

2. The stirring paddle as described in claim 1, characterized in that, The first impeller is inclined to the plane of rotation of the stirring shaft axis, and when the first impeller rotates, it generates both axial flow and radial flow.

3. The stirring paddle as described in claim 1, characterized in that, The end of the first blade away from the stirring shaft is arc-shaped.

4. The stirring paddle as described in claim 1, characterized in that, The first blade has at least four blades.

5. The stirring paddle as described in claim 1, characterized in that, The center of the stirring shaft in the radial direction is hollowed out.

6. The stirring paddle as described in claim 1, characterized in that, The second blade extends radially along the stirring shaft, and the second blade is arranged in an arc shape along the stirring shaft.

7. The stirring paddle as described in claim 1, characterized in that, A connecting block is provided between two adjacent second blades. The connecting block is located between the two annular disks and is arranged at intervals along the circumference of the stirring shaft.

8. The stirring paddle as described in claim 1, characterized in that, Multiple arc-shaped plates are provided between the inner rings of the two annular disks, and each arc-shaped plate is spaced apart circumferentially along the stirring shaft.

9. The stirring paddle as described in claim 8, characterized in that, A connecting block is provided between two adjacent second blades; The arc-shaped plate is provided with two connecting blocks and a second impeller on the side away from the stirring shaft.

10. A cell culture bioreactor, characterized in that, include: container; A drive unit is mounted on the container; A stirring paddle, driven and connected to the driving device, includes the stirring paddle as described in claims 1-9.

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