MIXING SYSTEM, MIXING DEVICE, CONTAINER AND METHOD FOR MIXING A FLUID AND / OR A SOLID

Description

[0001] The invention relates to a mixing system and a method for mixing a fluid and / or a solid.

[0002] Mixing systems such as bioreactors and pallet tanks are used for the collection, storage, and mixing of biological media such as fluids and / or solids. Biological media can be provided in containers such as bags, which can have a volume of several hundred liters. The biological media are introduced into the bioreactor within such a bag, where they can be stored, tempered, and / or mixed. In such a bioreactor, various tests can be conducted on the biological medium.

[0003] The bioreactor is typically handled in a sterile environment. Mixing of the biological medium can be achieved using a rotating stirring element located inside the bag and driven from outside the bag. The stirring element in contact with the medium is driven in rotation without the need to insert a rotating element, such as a stirrer shaft, into the sterile area inside the bag. The stirring element drive does not come into contact with the medium, is not contaminated, and does not need to be cleaned and / or sterilized for subsequent processing. Furthermore, a complex seal on a rotary union in the bag is eliminated.

[0004] For this purpose, a mixing device is known from the prior art in which a media-contacting stirring element is coupled to an external drive motor via a permanent magnet-based coupling. Two mutually assigned coupling halves are equipped with permanent magnets. Of the two opposing coupling halves, one is arranged inside the bag and is designed to be in contact with the media, while the other is arranged outside the bag and is designed to be non-media-contacting. The permanent magnets are aligned in such a way that they attract one another and transfer torque from an outer coupling half, driven by the drive motor, to an inner coupling half, which rotates with the stirring element.

[0005] Document EP 2 813 281 A1 relates to a bioreactor consisting of a bag for containing a fluid, wherein the bag has a rigid receptacle facing the interior of the bag. At least one transparent tube can be pushed through the rigid receptacle with a closed end so that it communicates with the interior of the bag.

[0006] Document EP 2 065 085 A1 relates to a mixing device comprising a container for mixing media, which container has at least one inlet or at least one outlet. A central recess extends longitudinally into the container and is separated from the interior of the container by a wall. A permanent-magnetic mixing element for mixing the media is arranged in the container adjacent to the recess. A drive unit arranged in the recess can set the mixing element in rotation via a magnetic coupling. The drive unit is movably arranged in the recess, so that the position of the mixing element in the container can be changed.

[0007] Document WO 2013 / 040161 A1 discloses a mixing system and method according to the preambles of claims 1 and 11. It discloses mixing systems for reaction vessels with flexible walls. The orientation of a magnetic coupling between impeller magnets and external drive magnets is modified so that the coupling is neither strictly axial nor strictly radial. "Receptacle-less" holding configurations are also disclosed, whereby a disposable container does not need a rigid base defining a cup or rod to engage a rotatable stirrer.

[0008] The existing mixing system with permanent magnets has several disadvantages. To transmit high torque, the existing mixing system requires powerful and thus relatively large and expensive permanent magnets. Therefore, the costs for the connecting structures, especially for the coupling, are relatively high and become particularly significant when bag systems are used, in which the coupling half in contact with the media, containing the expensive permanent magnets, is disposed of.

[0009] To prevent the coupling from slipping, the magnetic attraction force of the permanent magnets is designed for the maximum torque to be transmitted. All connected components in the power flow during power transmission, such as a housing, a ball bearing, a bag connection, etc., are subjected to the maximum attractive force of the permanent magnets, regardless of the actual torque transmitted. At lower torques, this can lead to unnecessary noise and / or heat development, or even to the creation of abrasion. Furthermore, the high permanent attractive force between the coupling halves makes assembling and disassembling the bag more difficult, as there is a risk of getting caught when the coupling half snaps shut. In addition, when disassembling the bag, a high attractive force must first be overcome in order to separate the coupling halves. There is also a risk thatExisting medical implants of the operating personnel could be affected by the strong permanent magnets. Finally, the design with a permanent magnetic coupling and separate drive motor results in a relatively high drive unit, which can be disadvantageous, especially in low ceilings where the mixing device is used.

[0010] The invention is based on the object of enabling an improved mixing system which reduces at least one of the disadvantages described above.

[0011] This object is achieved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims.

[0012] A first aspect relates to a mixing system according to the wording of claim 1, in particular a bioreactor and / or a pallet tank, for mixing a fluid and / or a solid with a container, wherein the fluid and / or the solid and a rotatable stirring element for mixing the fluid and / or the solid are arranged inside the container. The mixing system comprises a mixing device with a receptacle for receiving the container and a drive device for driving the stirring element. The drive device comprises a stator of a three-phase machine, and the stirring element comprises a rotor of the three-phase machine. Furthermore, the rotor comprises at least one permanent magnet and / or at least one squirrel-cage rotor.

[0013] The mixing device can be designed, in particular, as a bioreactor and / or a pallet tank of the type described above. The mixing device has a receptacle into which the container can be introduced. The container contains the fluid and / or the solid that is mixed in the mixing device. The container can be designed as a flexible bag, i.e., having a flexible bag wall. Alternatively, the container can have substantially stiff and / or rigid container walls, which can be made, for example, of metal or a hard plastic. The container can be designed as a so-called "single-use bag," i.e., a disposable bag that can be disposed of after the mixing process. For this purpose, the container can be designed, in particular, from a plastic, such as a transparent plastic. In addition to the fluid and / or solid, the container also has the stirring element, with which a stirring movement is performed during mixing.For this purpose, the stirring element in particular has a stirring shaft and / or is designed as a stirring shaft.

[0014] The receptacle can be designed to receive and / or support a predetermined container. For example, if a flexible bag is provided as the container, the receptacle can be designed as a substantially rigid container, i.e., have substantially rigid container walls. If a substantially rigid container is provided, the receptacle can be designed as a support for the container with stationary coupling attachments for the agitator shaft.

[0015] The stirring element is driven by the drive device of the mixing device, i.e. it is set in a rotational movement during which the stirring element executes a rotational movement through the fluid and / or the solid inside the container. The fluid or the solid is mixed in the process. The drive device can in particular be arranged adjacent to the receptacle, e.g. directly above the receptacle or formed on and / or in the base of the receptacle. Before the mixing process begins, the stirring element arranged in the container is coupled to the drive device arranged outside the container. The coupling takes place through the container and is sufficiently strong to mount an end of the stirring element facing the drive device on the drive device.

[0016] The rotational movement of the stirring element is caused by the three-phase machine, which is operated as an electric motor and drives the stirring element. In particular, the three-phase machine can be operated as a three-phase motor, i.e. with three-phase alternating current. As is usual and previously known, the three-phase machine has both a stator and a rotor. The stator is a component of the drive device. In particular, the drive device can also be designed as the stator. The stator is essentially stationary and, in particular, does not perform any rotational movement in the earth's reference system. The rotor is designed as a component of the stirring element; in particular, the stirring element can be designed as the rotor. The rotor can, in particular, be designed at the end of the stirring element that faces the drive device in an operating position.A rotational movement of the rotor also directly causes a rotational movement of the stirring element and / or a stirring shaft of the stirring element, which is rigidly connected to the rotor.

[0017] In the mixing device, the rotor is coupled to the stator in such a way that when the three-phase machine is operating, the rotor rotates inside the container. The rotor is coupled to the stator through and / or over a wall of the container. The stator can have one or more electrical coils that are supplied with electrical current. The coils can be operated with a three-phase current, for example. The coils generate magnetic fields that interact with the rotor, which in turn has a magnetic field generated by its permanent magnet and / or its squirrel-cage rotor. The interaction of the magnetic fields involved generates the rotational movement of the stirring element.

[0018] The principle of a squirrel-cage rotor (also known as a cage rotor) is generally familiar to those skilled in the art. In a squirrel-cage rotor, current is induced by the stator in a permanently short-circuited cage with massive windings. As a result, the squirrel-cage rotor acts as a magnet, whose magnetic field interacts with the stator's magnetic field, thereby causing the rotor to rotate.

[0019] In the mixing system, the drive device is designed as a non-media-contacting (also referred to as "non-media-contacting") part. This means that the drive device is not in contact with the fluid and / or solid to be mixed, especially not during the mixing process. The stirring element arranged in the container of the mixing system is designed to be in contact with the media (also referred to as "media-contacting") and is thus in contact with the fluid and / or solid.

[0020] The stator may have a coil arrangement supplied with three-phase current via a frequency converter. A magnetic field induced by the three-phase current from the coils of the coil arrangement, the so-called stator magnetic field, attracts the permanent magnet and / or the squirrel-cage rotor of the rotor, thus causing it to rotate.

[0021] The rotor can in particular be designed without permanent magnets and only have the squirrel-cage rotor or cage rotor, wherein in this embodiment the rotor magnetic field is caused by the stator magnetic field generated in the coils of the stator and a relative movement of the cage rotor, according to the principle of the asynchronous motor.

[0022] The stator is designed as a non-wetting element of the three-phase machine, while the rotor is designed as a wetted element of the three-phase machine. A separate coupling is not necessary, as no torque needs to be transferred from outside the vessel to the interior; instead, the torque can be generated directly and exclusively by the three-phase machine within the vessel.

[0023] The mixing system according to the invention eliminates the need for an additional (e.g., external) rotary drive, the torque of which must be transmitted to the stirring element. Thus, all elements of the mixing device can be stationary and non-rotating, while only the stirring element performs a rotational movement during mixing. In particular, no rotational movement of any element of the mixing device arranged outside the container is necessary and / or intended.

[0024] The drive device can have a coil arrangement as a non-media-contacting part that generates an electromagnetic rotating field. Compared to the previously known mixing device, the permanent magnets of the rotor can therefore be smaller and / or less powerful, for example, while maintaining the same torque to be transmitted, or they can be replaced by a simple and cost-effective metallic rotor, namely a squirrel-cage rotor. This is a cost advantage, especially when using disposable bags as containers, since only less expensive permanent magnets or none at all are disposed of. This enables a cost-effective design with space savings and material savings for the connecting components.

[0025] By controlling the stator, particularly the three-phase current through stator coils, the attractive force between the stator and rotor can be adjusted to the torque required at any given moment. Thus, the coupling's connecting parts are only subjected to a high attractive force when it is actually needed to transmit high torque. This can reduce noise, heat generation, and wear.

[0026] Since the attractive force between the stator and rotor can be controlled by the applied voltage or three-phase current, the attractive force can be reduced and / or switched off during assembly and / or disassembly. This allows for safe and easy assembly and disassembly of the bag during non-mixing times, even when high torques are generated during mixing. Furthermore, the reduced magnetic fields on the bearings, the three-phase motor, and the drive reduce or eliminate the risk of interference with medical implants worn by operating personnel.

[0027] By using the stator and rotor as an electromagnetic clutch, an additional rotary drive, whose torque would have to be transmitted to the stirring element, is eliminated. By eliminating such an additional external rotary drive, the overall height of the mixing device can be reduced.

[0028] When using a purely metallic rotor without permanent magnets (i.e. the variant in which the rotor is only a squirrel cage rotor and no

[0029] Permanent magnets), the disposal of the media-wetted elements, i.e. the rotor, is simplified compared to the disposal of a rotor with permanent magnets.

[0030] The drive device operates essentially wear-free in the non-media contact area, since all rotating elements, namely all elements of the stirring element including the rotor, are formed in the media contact area and can be disposed of together with the container after the mixing process.

[0031] According to one embodiment, during operation of the mixing device, a rotor magnetic field caused by the rotor interacts with a stator magnetic field generated by the stator. The interaction of the two magnetic fields causes the rotational movement of the stirring element. The rotor magnetic field caused by the rotor can be the magnetic field of the at least one permanent magnet of the rotor and / or the magnetic field generated by the at least one squirrel-cage rotor. The two magnetic fields interact with each other according to the principle of a three-phase motor and / or an asynchronous motor.

[0032] According to one embodiment, the stirring element is mounted on the drive device by means of electrically controllable magnetic force. The stator and the rotor form a coupling of the stirring element to the drive device. The stirring element is mounted, in particular, with the rotor, on the stator of the drive device. The stirring element can be mounted such that it is stationary and rotatable. The stirring element rotates about its axis of rotation when driven by the drive device. The mounting of the stirring element on the drive device is at least partially magnetic. In addition, the mounting can be mechanically assisted. Alternatively, the coupling can be purely magnetic. In this case, during assembly of the stirring element, the stator is supplied with current at least sufficiently strong to ensure that an attraction between the stator and rotor can be used to securely mount the stirring element.The magnetic force can be controlled electrically by controlling and / or adjusting the current flow through at least one electromagnetic coil of the stator.

[0033] According to one embodiment, the stirring element is in contact with the fluid and / or solid. The drive device is not in contact with the fluid and / or solid. Thus, the stirring element is designed as a media-contacting element, while the drive device is designed as a non-media-contacting element. In this case, no component of the drive device penetrates the container. Furthermore, a particularly efficient separation of the elements of the mixing device is provided. Since no component of the drive device penetrates the container, the drive device only needs to meet low sterility requirements and does not need to be cleaned and / or sterilized after each process.

[0034] According to one embodiment, the mixing device has a controller for controlling at least one electrical coil of the stator. The stator has at least one electrical coil, preferably several electrical coils. The stator can thus be designed as a coil arrangement with several electrical coils. A controller controls the electrical coil(s) of the stator. In doing so, the current and / or the voltage flowing through the electrical coil or applied to it is controlled and / or adjusted. The controller allows the attractive force between the stator and rotor to be adjusted, in particular during assembly and disassembly of the stirring element in the mixing device. Likewise, the attractive force during the mixing process is controlled and / or adjusted by the controller. The control can be carried out, for example, by means of at least one potentiometer and / or digitally using an IC and / or a processor such as a computer.The control improves control of mixing and / or assembly / disassembly.

[0035] According to a further development of this embodiment, the controller controls and / or adjusts an attractive force between the rotor and stator on the one hand and / or a rotational speed of the rotor on the other hand. Controlling the attractive force is particularly advantageous during assembly and disassembly of the stirring element on or in the drive device. Controlling and / or adjusting the rotational speed of the rotor corresponds to controlling and / or adjusting the rotational speed of the stirring element through the medium, i.e., the fluid and / or the solid. The mixing process is controlled by controlling the rotational speed. This provides essentially complete control of the mixing process, in particular the strength, intensity, and / or duration of the mixing process.

[0036] According to one embodiment, the container is designed as a flexible bag. The mixing device comprises a receptacle for receiving the flexible bag. The receptacle is designed as a receptacle and is configured to securely support the flexible bag during stirring. For this purpose, the container can have rigid walls on which elements of the mixing device can be supported and / or stored.

[0037] According to one embodiment, the mixing device has a speed monitoring device for the stirring element. The speed monitoring device can be optical, acoustic, and / or inductive, etc. The speed monitoring device can be configured as part of the aforementioned control system. The speed monitoring device can, on the one hand, provide control of the currently achieved speed of the stirring element, and, on the other hand, also, for example, allow a maximum and / or minimum of a desired speed of the stirring element to be set. Thus, the speed monitoring device can be configured to prevent a maximum speed from being exceeded, for example to limit the generation of heat and / or abrasion and / or noise.

[0038] According to one embodiment, the mixing device has a magnetic force limiter and / or torque limiter of the three-phase motor. The magnetic force limiter and / or torque limiter can be implemented as part of the aforementioned control system. Similar to the speed monitoring device, the magnetic force limiter and / or torque limiter can limit and / or reduce the generation of heat, noise, and / or wear on the mixing device. The magnetic force limiter and / or torque limiter can be implemented by limiting the three-phase current applied to the stator.

[0039] According to one embodiment, the mixing device is designed as a bioreactor, and the fluid and / or the solid is designed as a biological fluid and / or a biological solid. The mixing device is particularly efficient and advantageous in a bioreactor, since all components in contact with the media must meet strict sterility requirements. The drive device and thus also the stator of the three-phase motor can be designed as non-media-contacting parts of the bioreactor, which is why lower sterility requirements need to be met for these parts. The bioreactor can have additional elements such as a temperature control device and / or supply lines for additional media for feeding into and out of the container.

[0040] According to one embodiment, the three-phase machine is designed as an axial three-phase machine, in which a rotational axis of the rotor is aligned substantially parallel to the coil axes of the stator coils. The stator coils are arranged substantially parallel to one another, in particular in a circle around the rotational axis of the rotor. The rotor can be arranged, for example, below or above the stator coils.

[0041] According to an alternative embodiment, the three-phase machine is designed as a radial three-phase machine, in which a rotational axis of the rotor is aligned substantially perpendicular to the coil axes of the radial coils of the stator. In this embodiment, the rotor can be arranged centrally between the circularly inwardly oriented coil axes of the stator, similar to a conventional electric motor.

[0042] A mixing device is disclosed, in particular a bioreactor and / or pallet tank, for mixing a fluid and / or a solid, comprising a receptacle for receiving a container, wherein the fluid and / or the solid and a rotatable stirring element for mixing the fluid and / or the solid are arranged inside the container, and a drive device for driving the stirring element. The drive device comprises a stator of a three-phase machine. The drive device is designed and provided to drive the stirring element, which has a rotor of the three-phase machine, wherein the rotor has at least one permanent magnet and / or at least one squirrel-cage rotor. The mixing device according to the second aspect can be designed as part of the mixing system according to the first aspect.Therefore, the embodiments and examples of the mixing device of the mixing system according to the first aspect also relate to the mixing device according to the second aspect.

[0043] A container for mixing a particularly biological fluid and / or a particularly biological solid in a mixing device is disclosed. The fluid and / or the solid, as well as a rotatable stirring element for mixing the fluid and / or the solid, are arranged inside the container. The stirring element has a rotor of a three-phase machine, wherein the rotor has at least one permanent magnet and / or at least one squirrel-cage rotor. The container can be configured as part of the mixing system according to the first aspect.

[0044] A second aspect relates to a method for mixing a particularly biological fluid and / or a particularly biological solid according to claim 11, wherein a container is provided, wherein the fluid and / or the solid is arranged in the interior of the container, the fluid and / or the solid is mixed by means of at least one rotatable stirring element arranged in the interior of the container, wherein the stirring element has a rotor of a three-phase machine, the stirring element is driven by a drive device, wherein the drive device has a stator of the three-phase machine and the rotor has at least one permanent magnet and / or at least one squirrel-cage rotor.

[0045] To carry out the method, a mixing system according to the first aspect can be used. Therefore, all embodiments and examples described in connection with the first aspect also apply to the method according to the second aspect, and vice versa.

[0046] According to one embodiment of the method, the three-phase machine is operated as an electric motor, in particular as a three-phase motor, to drive the stirring element.

[0047] According to one embodiment, the drive device has coils to which periodically changing voltages are applied, such that a first of the coils generates a first magnetic field whose temporal profile is offset from the temporal profile of at least a second magnetic field of a second of the coils. The drive device can in particular have three coils or an integer multiple of three coils (e.g. six or nine coils), wherein the coils are each fed with a conductor voltage phase of a three-phase current system. The coils of the drive device can be arranged in a circle such that the individual coil magnetic fields of the coils result in an overall magnetic field which is essentially of constant size and / or strength and continuously changes its orientation in accordance with the frequency and / or period repetition of the three-phase current.If the coils are arranged in a circle, the overall magnetic field "rotates" in this circle at a controllable speed.

[0048] The invention is explained in more detail below with reference to exemplary embodiments shown in the figures. Individual features shown in the figures can be combined with other exemplary embodiments. The same reference numerals designate the same or similar components of the embodiments. They show: Figure 1 shows a side view of a mixing system with a three-phase motor; Figure 2 shows a cross-section through a drive device of a mixing device; Figure 3A shows a cross-section through a three-phase motor of a mixing system during operation under magnetic flux through opposing coils; Figure 3B shows a cross-section through a three-phase motor of a mixing system during operation under magnetic flux through adjacent coils; Figure 4 shows a sectional view of an axial three-phase motor of a mixing system; and Figure 5 shows a sectional view of a radial three-phase motor of a mixing system.

[0049] Figure 1shows a side view of a mixing system with a three-phase motor 10 as a three-phase machine. The mixing system has a mixing device 1, which is designed and provided to mix a medium 8, which is arranged in a container 4 of the mixing device 1. The medium 8 is designed as a fluid and / or solid and can in particular be designed as a fluid mixture and / or a solid mixture or mixture, or also as a mixture of at least one fluid and at least one solid.

[0050] In the embodiment shown, the container 4 is designed as a flexible bag and is penetrated by a stirring element 3 which is arranged inside the container 4 and can completely penetrate the container 4 from one end to the opposite end. The stirring element 3 and the medium 8 are arranged inside the container, which in turn is introduced and stored in a receptacle of the mixing device 1. The receptacle of the mixing device 1 can be designed as a substantially rigid container into which the container 4 is introduced. The container or bag 4 can be designed as a disposable bag and / or disposed of after the process together with the residues of the fluid and / or solid and together with the stirring element 3.

[0051] The mixing device 1 can be designed as an element of a mixing system comprising the mixing device 1 and the container 4. The mixing device 1 can be designed, in particular, as a bioreactor for receiving, storing, and mixing a biological fluid and / or solid. In other embodiments, the container 4 and the associated receptacle of the mixing device 1 can have other shapes, for example, be substantially cylindrical, bucket-shaped, spherical, ellipsoidal, cuboid-shaped, or similar.

[0052] The three-phase motor 10 of the mixing system can be operated with three-phase alternating current, also referred to as three-phase current. At least three coils (in alternative embodiments, a multiple of three coils) of the three-phase motor 10 are each supplied with a line voltage phase of a three-phase current system, so that a coil magnetic field is generated in and / or by each coil, the temporal profile of which is offset by one-third of a period from the voltage profile and coil magnetic field of at least two other coils. This creates a "rotating" overall magnetic field composed of the individual coil magnetic fields, which drives the stirring element.

[0053] The mixing device 1 further comprises a drive device 2, which is arranged outside the container 4. The drive device 2 is arranged directly adjacent to the container 4. The drive device 2 is arranged substantially in the middle of a container wall of the container 4, in the embodiment shown on the upper container wall of the container 4. The stirring element 3 is coupled to the drive device 2. The stirring element 3 has a stirring shaft 9, which is substantially rod-shaped. The stirring shaft 9 is arranged substantially completely inside the container 4 and penetrates the container 4 completely from a first end of the container 4 to a second end of the container 4. In the embodiment shown, the stirring shaft 9 is mounted at two opposite ends of the container 4. Thus, the stirring shaft 9 is mounted on a drive-side bearing 6 and on a counter-bearing 7. In the embodiment shown in Figure 1In the embodiment shown, the drive-side bearing 6 is arranged directly adjacent to the drive device 2, while the counter-bearing 7 is arranged on the side of the container 4 opposite the drive device 2. Thus, the drive-side bearing can be formed at an upper end of the container 4 and the counter-bearing 7 in or on the bottom surface of the container 4. In alternative embodiments, the drive-side bearing can also be formed in the bottom of the container 4 or in a side wall of the container 4, while the counter-bearing is arranged on the opposite side of the container.

[0054] Formed on the agitator shaft 9 are several agitator extensions 5, which move through the medium 8 as the agitator shaft 9 rotates around a rotational axis R of the agitator element 3, thereby thoroughly mixing the medium. In the illustrated embodiment, the agitator extensions 5 are screw-like, i.e., similar in shape to a ship's propeller. However, the agitator extensions 5 can also have a different shape and be designed to thoroughly mix the medium 8.

[0055] In the illustrated embodiment, the rotation axis R is arranged essentially vertically in the Earth's reference system. The rotation axis R is a rotational symmetry axis of the rod-shaped agitator shaft 9 and runs essentially perpendicularly from the drive device 2 (or the container wall on which the drive device is arranged) into the interior of the container 4.

[0056] The rotary motor 10 comprises the drive device 2 and parts of the stirring element 3, in particular parts of the stirring element 3 mounted on the drive-side bearing 6. The three-phase motor 10 has in particular a stator and a rotor, embodiments of which are described in more detail in the next figures.

[0057] Figure 2 shows a cross section through the drive device 2 of the Figure 1 shown mixing device 1. The cross section shown shows a section through a plane ZZ, which in Figure 1 and is arranged substantially horizontally in the Earth's reference system through the drive device 2. The section plane ZZ also runs substantially parallel to that container wall 4' of the container 4 (cf. Figure 1), on or in which the drive device 2 is formed. The container wall 4' is the upper container wall of the container 4. Alternatively, another container wall of the container 4 could also be used to arrange the drive device 2 there.

[0058] The drive device 2 comprises a stator 20 of the three-phase motor 10, which has a plurality of coils 21. In the illustrated embodiment, the stator 20 comprises six substantially equal and similar coils 21, which are arranged symmetrically in a circle around the rotation axis R. The coil axes of the coils 21 are arranged parallel to the rotation axis.

[0059] Figure 3Ashows a cross-section through the three-phase motor 10, namely through the stator 20 as well as through a rotor 30 of the three-phase motor 10. The rotation axis R lies in the section plane of the cross-section shown. The cross-section runs through a plane AA, which in Figure 2 and runs vertically through the center of the stator 20. In the Figure 1 In the embodiment shown, the cutting axis is thus a vertical cutting axis in the Earth's reference system.

[0060] In addition to a coil core 22 and the coils 21, the stator 20 further comprises a stator housing 23 and a clamping projection 24. The stator housing 23 serves to securely and stationary fix and / or arrange the coils 21 of the stator 20. The stator housing 23, like the entire stator 20, is stationary and non-rotatable.

[0061] The clamping projection 24 is formed on the side of the stator housing 23 facing the rotor 30 and serves to support a rotor housing 33 of the rotor 30. For this purpose, the rotor housing 33 has a clamping insert 34, which can be connected to the clamping projection 24 of the stator, e.g., by a clamp. In the operating state, the clamping projection 24 and the clamping insert 34 are in a clamp fit, in which the rotor housing 33 is rigidly clamped to the stator housing 23.

[0062] In the embodiment shown, the clamping projection 24 and the clamping insert 34 are configured to completely surround the three-phase motor 10. In other embodiments, the clamping projection and clamping insert may only partially surround the three-phase motor, be configured only at individual locations on the housing, and / or another fastening mechanism may be provided for mounting the rotor housing 33 to the stator housing 23.

[0063] The rotor housing 33 penetrates the container wall 4' at an opening and is mounted and / or fastened to the stator housing 23 in this opening in the container wall 4'. The rotor housing 33 has a stationary pin 32 whose central axis coincides with the rotation axis R and which (like the rotor housing 33) is stationary and non-rotatable. A ball bearing 36 is arranged around the stationary pin 32 and is rotatable about the stationary pin 32 and about the rotation axis R. Mounted on the ball bearing 36 are several permanent magnets 31 of the rotor 30, which can move around the stationary pin 32 and thereby perform a rotational movement about the rotation axis R. The permanent magnets 31 form a rotatable part of the rotor 30, to which the agitator shaft 9 is rigidly coupled. When the rotor 30, or more precisely the permanent magnet 31, rotates around the rotation axis R, the stirring shaft 9 also rotates around the rotation axis R.

[0064] In an alternative design, the rotor is mounted in the rotor housing with a different bearing, e.g. without a pin and with an external bearing.

[0065] In Figure 3A Also shown is a magnetic flux MG through opposite coils 21 of the stator 20 and through opposite permanent magnets 31 of the rotor 30. In the Figure 3A In the control of the three-phase motor 10 shown, the magnetic flux MG thus runs through opposing coils and opposing permanent magnets.

[0066] Alternatively, the same three-phase motor 10 can also be controlled in such a way that a magnetic flux MN passes through adjacent coils 21 of the stator 20 and through adjacent permanent magnets 31 of the rotor 30. This control is shown in Figure 3B shown cross section through the three-phase motor 10. The Figure 3B The cross section shown is parallel to the one shown in Figure 3Ashown cross-section and shows a section through a cutting plane BB, which is also in Figure 2 is shown.

[0067] By means of a control not shown in the figures, the coils 21 of the three-phase motor 10 can be selectively operated as shown in Figure 3A shown or as in Figure 3Bshown. In addition, the controller can adjust the current intensity and thus the force of attraction between the coils 21 and the permanent magnets 31. With the three-phase motor 10 shown, the agitator shaft 9, which is mounted in the media-contacting area, can be driven without a rotating element of the drive having to be inserted through the bag 4 into, for example, the sterile area. In this way, the drive does not come into contact with the medium, is not contaminated, and does not need to be cleaned and / or sterilized for a subsequent process. Furthermore, there is no need for complex sealing of a rotary feedthrough into the media-contacting area.

[0068] As in the Figures 3A and 3BAs shown, the magnetic fields MG and / or MN can be configured differently, depending on the geometric arrangement and electrical control of the coils 21 and the design of the rotor 30. The arrangement and wiring can be optimized to create a magnetic flux through two adjacent coil-magnet pairs or through two opposing coil-magnet pairs. The coils 21 are each controlled in such a way that the generated magnetic field displaces the rotor 30 in a desired direction of rotation around the rotation axis R, thus creating the magnetic field between the next coil pair in the direction of rotation and the next permanent magnet. The rotor 30 synchronously follows the rotating field of the coils 21.

[0069] In an alternative embodiment of the rotor, the rotor does not have permanent magnets, but rather one or more squirrel-cage rotors. In this case, a rapidly rotating magnetic field of the coils 21 in the rotor, which is constructed from laminated cores with short-circuited windings and / or a cast core, generates a current flow that induces a magnetic field in the rotor. Due to the attractive force between the rotating field of the stator coils and the induced magnetic field in the rotor, the rotor follows the rotating field. The rotor follows the rotating field asynchronously, i.e., at a lower speed than the rotating field.

[0070] Figure 4 shows a sectional view through an axial three-phase motor 10 of a mixing device. The axial three-phase motor 10 corresponds to the Figure 2 , 3A and 3Bshown three-phase motor 10. The section plane shown runs through the rotation axis R. In the axial three-phase motor 10, both the coil axes of the coils 21 are arranged essentially parallel to the rotation axis R, and the permanent magnets 31 of the rotor 30 are aligned essentially parallel to the rotation axis R. "Alignment of the permanent magnets" means the alignment of the magnetic north pole to the magnetic south pole. In the Figure 4 In the embodiment shown, the magnetic south poles are arranged exactly above the magnetic north poles, parallel to the rotation axis R. The three-phase motor 10 is thus designed as a so-called axial three-phase motor 10.

[0071] Figure 5 shows a radial three-phase motor 11. The radial three-phase motor 11 is similar to the axial three-phase motor 10 and has some identical or similar components. The section plane of the Figure 5shown cross-section includes the rotation axis R. The stator 20 has radial coils 21', the coil axes of which are arranged substantially perpendicular to the rotation axis R. More precisely, the radial coils 21' are arranged in a circle around the rotation axis R such that their coil axes point substantially perpendicular to the rotation axis R. When current flows through the radial coils 21', a magnetic field is generated, i.e. a stator magnetic field, which interacts with radial permanent magnets 31' of the rotor 30. The radial permanent magnets 31' are also arranged substantially circularly and perpendicular to the rotation axis R. Either the magnetic north pole or the magnetic south pole points outwards in the direction of a radial coil 21'.

[0072] In the radial three-phase motor 11, the rotor 30 fully engages a recess in the stator 20, with the rotor 30 being at least partially mounted inside the stator 20. As in the previously described embodiment, a rotational movement of the rotor 30 about the rotation axis R causes a rotation (i.e., rotation) of the agitator shaft 9, which is coupled to the rotor 30. The rotor 30 is mounted on a rotor bearing 35, which has an opening through which the agitator shaft 9 is coupled to the head of the rotor with the radial permanent magnets 31'. The rotor bearing 35, as part of a rotor housing, is connected to the container wall 4', is stationary and non-rotatable, and can form a clamp fit with the stator housing 23.

[0073] The coupling between the rotor and stator can therefore be constructed either axially, for example as in the axial three-phase motor 10, which is Figure 4shown, or be constructed radially, for example as in the radial three-phase motor 11, which is shown in Figure 5 In both embodiments, the rotor 30, agitator shafts 9, in particular the permanent magnets 31 and 31', i.e., the entire agitator element 3, are arranged inside the container 4 and thus designed to be in contact with the media. The stator housing 23 can be optimized for the wiring of the coils 21 and 21', and the position of the permanent magnets or squirrel cage rotors.

[0074] In both axial rotary motors and radial rotary motors, the (non-media-contacting) stator housing can be clamped to the (media-contacting) rotor housing. The rotor housing 33 is stationary and non-rotatable, serving as a stationary and non-rotatable bearing for the agitator shafts 9, the permanent magnets 31, 31', and the squirrel-cage rotor(s).

[0075] Instead of a clamp connection between the stator housing and the rotor housing, screw connections, magnetic couplings and / or other fastenings can be provided. The agitator shaft 9 can be mounted on the drive device 2 on the one hand and on the other hand, as shown in Figure 1 shown, also on a counter bearing 7. Alternatively, the stirring element 3 can be mounted on only one side, namely on the drive-side bearing 6. In such an embodiment, the stirring element does not completely penetrate the container 4, but merely projects from one wall of the container 4 into the interior of the container 4. The double bearing, i.e. the bearing on opposite walls of the container 4, however, increases the stability of the stirring shaft during its rotational movement. Reference symbol list

[0076] 1 Mixing device 2 Drive device 3 Stirring element 4 Container or bag 4 Container wall 5 Stirring extension 6 Drive-side bearing 7 Counter bearing 8 Medium 9 Stirring shaft 10 Axial three-phase machine 11 Radial three-phase machine 20 Stator 21 Coil 21 Radial coil 22 Coil core 23 Stator housing 24 Clamping projection 30 Rotor 31 Permanent magnet 31 Radial permanent magnet 32 ​​Stationary pin 33 Rotor housing 34 Clamping insert 35 Rotor bearing 36 Ball bearing R Rotation axis MG Magnetic flux through opposite coils MN Magnetic flux through adjacent coils

Claims

1. Mixing system, in particular a bioreactor and / or a pallet tank, for mixing a fluid and / or a solid, comprising: - a container (4), wherein the fluid and / or the solid and a rotatable stirring element (3) for mixing the fluid and / or the solid are arranged in the interior of the container (4), and - a mixing device (1) comprising a holder for receiving the container (4) and a drive device (2) for driving the stirring element (3), wherein - the stirring element (3) comprises a stirring shaft (9) and / or is designed as a stirring shaft (9), wherein the stirring shaft (9) runs all the way through the container (4) from a first end of the container (4) to a second end of the container (4), characterized in that - the drive device comprises a stator of a three-phase machine, - the stirring element comprises a rotor of the three-phase machine, - the rotor comprises at least one permanent magnet and / or at least one squirrel-cage rotor.

2. Mixing system according to claim 1, wherein, during operation of the mixing device (1), a rotor magnetic field caused by the rotor (30) interacts with a stator magnetic field generated by the stator (20).

3. Mixing system according to any one of the preceding claims, wherein the stirring element (3) is mounted on the drive device (2) by way of an electrically activatable magnetic force.

4. Mixing system according to any one of the preceding claims, wherein the stirring element (3) is in physical contact with the fluid and / or solid, and the drive device (2) is not in physical contact with the fluid and / or solid.

5. Mixing system according to any one of the preceding claims, comprising a control unit for activating at least one electrical coil (21; 21') of the stator (20), wherein the control unit controls and / or sets a force of attraction between the rotor (30) and the stator (20) on the one hand and / or a rotational speed of the rotor (30) on the other hand.

6. Mixing system according to any one of the preceding claims, wherein the container (4) is designed as a flexible bag, and the mixing device (1) comprises a receptacle for receiving the flexible bag.

7. Mixing system according to any one of the preceding claims, comprising a rotational speed monitoring device of the stirring element (3).

8. Mixing system according to any one of the preceding claims, comprising a magnetic force limiting function and / or a torque limiting function of the three-phase machine (10; 11).

9. Mixing system according to any one of the preceding claims, wherein the mixing device (1) is designed as a bioreactor, and the fluid and / or the solid is in the form of a biological fluid and / or a biological solid.

10. Mixing system according to any one of the preceding claims, wherein the three-phase machine is designed as an axial three-phase machine (10), in which an axis of rotation (R) of the rotor (30) is oriented substantially parallel to coil axes of coils (21) of the stator (20); or wherein the three-phase machine is designed as a radial three-phase machine (11), in which an axis of rotation (R) of the rotor (30) is oriented substantially perpendicular to coil axes of radial coils (21') of the stator (20).

11. Method for mixing an in particular biological fluid and / or an in particular biological solid, wherein a container (4) is provided, wherein the fluid and / or the solid is arranged in the interior of the container (4), the fluid and / or the solid is mixed by means of at least one rotatable stirring element (3), which is arranged in the interior of the container (4), the stirring element (3) is driven by a drive device (2), the stirring element (3) comprises a stirring shaft (9) and / or is designed as a stirring shaft (9), wherein the stirring shaft (9) runs all the way through the container (4) from a first end of the container (4) to a second end of the container (4), characterized in that the drive device (2) comprises a stator (20) of a three-phase machine (10; 11), the stirring element (3) comprises a rotor (30) of the three-phase machine (10; 11), the rotor comprises at least one permanent magnet (31, 31') and / or at least one squirrel-cage rotor.

12. Method according to claim 11, wherein the three-phase machine (10; 11) is operated as an electric motor for driving the stirring element (3) and / or wherein the drive device (2) comprises coils (21; 21'), to which periodically alternating voltages are respectively applied, so that a first magnetic field is generated by a first of the coils (21; 21'), the curve of this field over time being temporally offset in relation to the curve of at least a second magnetic field of a second of the coils (21; 21') over time.