Mixing system, mixing device, container, and method for mixing a fluid and/or a solid

Abstract

The invention relates to a mixing system, in particular a bioreactor and/or a pallet tank, for mixing a fluid and/or solid, having 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). The mixing system furthermore has a mixing device (1) for receiving the container (4) and a drive device (2) for driving the stirring element (3). 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), and the rotor (30) has at least one permanent magnet (31; 31′) and/or at least one short circuit rotor.

Claims

1. A mixing system for mixing a fluid and/or a solid, comprising: a container (4) configured for containing the fluid and/or the solid; a rotatable stirring element (3) provided inside the container (4) and configured for mixing the fluid and/or the solid inside the container (4), the rotatable stirring element (3) comprising a stirring shaft (9) having opposite first and second ends and defining a rotational axis (R), the first and second ends of the stirring shaft (9) being connected respectively to a drive side mount (6) and a connector mount (7) at opposite positions in the container (4); and a driving device (2) for driving the stirring element (3), wherein the driving device (2) comprises: a three-phase machine (10; 11) having a stationary and non-rotatable stator housing (23) disposed at a position external of the container (4), and a stator (20) disposed in the stator housing (23); a rotor housing (33) mounted to the container (4), the rotor housing (33) having a stationary portion fixed relative to the stator housing (23) and a rotatable portion disposed in the container (4) and being rotatable about the rotational axis (R), the rotatable portion of the rotor housing including the drive side mount (6) to which the first end of the stirring shaft (9) is connected; and a rotor (30) of the three-phase machine (10; 11), the rotor (30) comprising permanent magnets (31; 31′) and/or at least one squirrel-cage rotor, the rotor (30) being mounted to the rotatable portion of rotor housing (33) for rotation with the rotatable portion of the rotor housing (33) and being disposed in the container (4) at a fixed axial position relative to the rotational axis (R) so that operation of the three-phase machine (10; 11) causes the rotor (30) to generate torque inside the container (4); wherein the three-phase machine (10; 11) generates a torque exclusively inside the container, and the torque rotates the rotor (30) relative to the stator (20) in response to operation of the driving device (2).

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

3. The mixing system of claim 1, wherein the stirring element (3) is mounted on the driving device (2) by way of an electrically activatable magnetic force.

4. The mixing system of claim 1, wherein the stirring element (3) is in contact with the fluid and/or solid, and the stator (20) of the driving device (2) is not in contact with the fluid and/or solid.

5. The mixing system of claim 1, comprising a control unit for activating at least one electrical coil (21; 21′) of the stator (20).

6. The mixing system of claim 5, wherein the control unit controls and/or sets a force of attraction between the rotor (30) and the stator (20) and a rotational speed of the rotor (30).

7. The mixing system of claim 1, wherein the container (4) is a flexible bag.

8. The mixing system according to of claim 1, comprising a magnetic force limiting function and/or a torque limiting function of the three-phase machine (10; 11).

9. The mixing system of claim 1, wherein the mixing device (1) is a bioreactor, and the fluid and/or the solid is a biological fluid and/or a biological solid.

10. The mixing system of claim 1, wherein the three-phase machine is an axial three-phase machine (10), and the rotor (30) has a rotational axis (R) oriented substantially parallel to coil axes of coils (21) of the stator (20), wherein the magnets (31, 31′) of the rotor (30) are disposed to align with the coil axes of the coils (21).

11. The mixing system of claim 1, further comprising stirring appendages (5) projecting from the rotatable stirring shaft (9) and configured for stirring contents of the container (4).

12. The mixing system of claim 1, wherein the stationary portion of the rotor housing (33) is fixed to the stator housing (23) by a clamping connection.

13. The mixing system of claim 1, wherein the stationary portion of the rotor housing (33) is fixed to the stator housing (23) by screw joints.

14. The mixing system of claim 1, wherein the stationary portion of the rotor housing (33) is fixed to the stator housing (23) by magnetic couplings.

15. A method for mixing a fluid and/or a solid, comprising: providing a container (4) with a container wall, a rotor housing (33), a rotor (30) and a rotatable stirring element (3), the rotor housing (33) having a non-rotatable portion fixed in a stationary and non-rotatable manner to the container wall of the container (4), the rotor housing (33) further having an internal portion inside the container (4) and rotatable with respect to the non-rotatable portion of the rotor housing (33), the rotor (30) being mounted to the internal portion of the rotor housing (33) for rotation with the rotatable portion of the rotor housing (33), the rotatable stirring element (3) comprising a stirring shaft (9) having opposite first and second ends, the first end of the stirring shaft (9) being connected in an axially fixed position to a drive side mount (6) on the rotatable portion of the rotor housing (33), the second end of the stirring shaft (9) being connected to a connector mount (7) on a side of the container (4) opposite the drive side mount (6), the rotor (30) being connected to and arranged at the first end of the stirring shaft (9) so that the rotor (30) and the stirring element (3) are rotatable in unison; providing a stator (20) of a three-phase machine (10; 11), the stator (20) comprising a stator housing (23); connecting the stator housing (23) to the external portion of the rotor housing (33) in an axially fixed non-rotatable position so that the stator (20) is opposed to the rotor (30) and so that the stator (20) and the rotor (30) form a driving device (2); placing the fluid and/or the solid into the container (4); and operating the three-phase machine (10; 11) so that the rotor (30) of the three-phase machine (10; 11) on the interior of the container (4) generates a torque exclusively inside the container (4), with the torque of the rotor (30) rotating the stirring element (3) in the interior of the container (4) while keeping the stirring element (3) in the axially fixed position and thereby mixing the fluid and/or the solid disposed inside the container (4).

16. The method of claim 15, wherein the three-phase machine (10; 11) is operated as an electric motor for driving the stirring element (3) and/or wherein the driving device (2) comprises coils (21; 21′), to which the respective periodically alternating voltages are applied, so that a first magnetic field is generated by a first of the coils (21; 21′), the progression of this field over time being chronologically offset compared to the progression of at least one second magnetic field of a second of the coils (21; 21′) over time.

17. A mixing system for mixing biological media, comprising: a container (4) configured for containing the biological media; a rotatable stirring element (3) provided inside the container (4) and configured for mixing the biological media inside the container (4), the rotatable stirring element (3) comprising a stirring shaft (9) having opposite first and second ends and defining a rotational axis (R), the first and second ends of the stirring shaft (9) being connected respectively to a drive side mount (6) and a connector mount (7) at opposite positions in the container (4); and a driving device (2) for driving the stirring element (3), wherein the driving device (2) comprises: a three-phase machine (10; 11) having a stationary and non-rotatable stator housing (23) disposed at a position external of the container (4), and a stator (20) disposed in the stator housing (23), the stator (20) having coils (21) with axes aligned substantially parallel to the stirring shaft (9); a rotor housing (33) mounted to the container (4), the rotor housing (33) having a stationary portion fixed relative to the stator housing (23) and a rotatable portion disposed in the container (4) and being rotatable about the rotational axis (R), the rotatable portion of the rotor housing including the drive side mount (6) to which the first end of the stirring shaft (9) is connected; and a rotor (30) of the three-phase machine (10; 11), the rotor (30) comprising permanent magnets (31; 31′) positioned to be aligned with the axes of the coils (21) of the stator (20), the rotor (30) being mounted to the rotatable portion of rotor housing (33) for rotation with the rotatable portion of the rotor housing (33) and being disposed in the container (4) at a fixed axial position relative to the rotational axis (R) so that operation of the three-phase machine (10; 11) causes the rotor (30) to generate torque inside the container (4); wherein the three-phase machine (10; 11) generates a torque exclusively inside the container, and the torque rotates the rotor (30) relative to the stator (20) in response to operation of the driving device (2).

Description

DETAILED DESCRIPTION

(1) FIG. 1 shows a side view of a mixing system comprising a three-phase motor.

(2) FIG. 2 shows a cross-sectional view through a driving device of a mixing device.

(3) FIG. 3A shows a cross-sectional view through a three-phase motor of a mixing system during operation under magnetic flux through opposing coils.

(4) FIG. 3B shows a cross-sectional view through a three-phase motor of a mixing system during operation under magnetic flux through adjoining coils.

(5) FIG. 4 shows a sectional illustration of an axial three-phase motor of a mixing system.

(6) FIG. 5 shows a sectional illustration of a radial three-phase motor of a mixing system.

DETAILED DESCRIPTION

(7) FIG. 1 shows a side view of a mixing system comprising a three-phase motor 10, serving as a three-phase machine. The mixing system comprises a mixing device 1, which is designed and provided to mix a medium 8 provided in a container 4 of the mixing device 1. The medium 8 is a fluid and/or a solid and can, in particular, be designed as a fluid mixture and/or a solid mixture or blend, or else as a mixture of at least one fluid and at least one solid.

(8) In the shown embodiment, the container 4 is designed as a flexible bag and is penetrated by a stirring element 3, which is disposed inside the container 4 and can completely penetrate the container 4 from one end to an opposite end. The stirring element 3 and the medium 8 are provided inside the container, which in turn is introduced and mounted in a holder of the mixing device 1. The holder of the mixing device 1 can be designed as a substantially rigid receptacle in which the container 4 is introduced. The container or bag 4 can be designed as a disposable bag and/or can be disposed of, after the process, together with the residue of the fluid and/or solid and together with the stirring element 3.

(9) 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, in particular, be designed 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 may have other shapes and can, for example, be substantially cylindrical, bucket-shaped, spherical, ellipsoidal, cuboid or the like.

(10) The three-phase motor 10 of the mixing system can be operated with three-phase AC current, which is 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 fed a line voltage phase of a three-phase system, so that a coil magnetic field is generated in and/or by each coil, the progression of which over time is offset by a third of a period from the voltage curve and coil magnetic field of at least two other coils. A “rotating” overall magnetic field is thus created, which is composed of the individual coil magnetic fields and drives the stirring element.

(11) The mixing device 1 furthermore comprises a driving device 2 disposed outside the container 4. The driving device 2 is disposed directly adjoining the container 4. The driving device 2 is disposed essentially in the center of a container wall of the container 4, and in the shown embodiment on the upper container wall of the container 4. The stirring element 3 is coupled to the driving device 2. The stirring element 3 comprises a stirring shaft 9, which is substantially rod-shaped. The stirring shaft 9 is disposed substantially completely inside the container 4 and can either protrude from one end of the container 4 into the container 4 or completely penetrate the container 4 from a first end of the container 4 to a second end of the container 4. In the shown embodiment, the stirring shaft 9 is mounted on two opposing ends of the container 4. The stirring shaft 9 is thus mounted on a drive-side mount 6 and on a counter mount 7. In the embodiment shown in FIG. 1, the drive-side mount 6 is disposed directly adjoining the driving device 2, while the counter mount 7 is disposed on the side of the container 4 located opposite the driving device 2. The drive-side mount can thus be formed at an upper container end of the container 4, and the counter mount 7 can be formed in or on the bottom surface of the container 4. In alternative embodiments, the drive-side mount can also be formed in the bottom of the container 4 or in a side wall of the container 4, while the counter mount is disposed on the respective opposite side of the container.

(12) Multiple stirring appendages 5 are formed on the stirring shaft 9, which during the rotation of the stirring shaft 9 about a rotational axis R of the stirring element 3 move through the medium 8, mixing the medium. The stirring appendages 5 have a propeller-like design in the shown embodiment, which is to say based on the shape of a ship's screw propeller. The stirring appendages 5, however, can also have another shape and be designed to mix the medium 8.

(13) In the shown exemplary embodiment, the rotational axis R is substantially vertical to the terrestrial reference system. The rotational axis R is a rotational axis of symmetry of the rod-shaped stirring shaft 9 and extends substantially perpendicularly away from the driving device 2 (or the container wall on which the driving device is disposed) to the inside of the container 4.

(14) The three-phase motor 10 comprises the driving device 2 and parts of the stirring element 3, in particular parts of the stirring element 3 mounted on the drive-side mount 6. The three-phase motor 10 in particular comprises a stator and a rotor, embodiments of which are described in more detail in the following figures.

(15) FIG. 2 shows a cross-sectional view through the driving device 2 of the mixing device 1 shown in FIG. 1. The shown cross-section shows a sectional view through a plane Z-Z, which is identified in FIG. 1 and disposed substantially horizontally in the terrestrial reference system through the driving device 2. Moreover, the cutting plane Z-Z extends substantially parallel to the container wall 4′ of the container 4 (see FIG. 1) on or in which the driving 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 dispose the driving device 2 there.

(16) The driving device 2 comprises a stator 20 of the three-phase motor 10, which comprises multiple coils 21. In the shown exemplary embodiment, the stator 20 comprises six substantially equally large and identical coils 21, which are disposed symmetrically about the rotational axis R in a circle. The axes of the coils 21 are disposed parallel to the rotational axis R.

(17) FIG. 3A shows a cross-sectional view through the three-phase motor 10, and more particularly through the stator 20 and through a rotor 30 of the three-phase motor 10. The rotational axis R is located in the cutting plane of the shown cross-section. The cross-section extends through a plane A-A, which is marked in FIG. 2 and runs perpendicularly through the center of the stator 20. In the embodiment shown in FIG. 1, the axis of intersection is thus a vertical axis of intersection in the terrestrial reference system.

(18) In addition to a coil core 22 and the coils 21, the stator 20 furthermore comprises a stator housing 23 and a clamping protrusion 24. The stator housing 23 is used to securely fix and/or dispose the coils 21 of the stator 20 in a stationary manner. Like the entire stator 20, the stator housing 23 is designed to be stationary and non-rotatable.

(19) The clamping protrusion 24 is formed on the side of the stator housing 23 facing the rotor 30 and is used to mount a rotor housing 33 of the rotor 30. For this purpose, the rotor housing 33 comprises a clamping insert 34, which can be connected to the clamping protrusion 24 of the stator, for example by way of a collar. In the operating state, the clamping protrusion 24 and the clamping insert 34 form a clamping seat in which the rotor housing 33 is rigid clamped to the stator housing 23.

(20) In the shown embodiment, the clamping protrusion 24 and the clamping insert 34 are designed so as to completely extend around the three-phase motor 10. In other embodiments, the clamping protrusion and the clamping insert may extend around the three-phase motor only partially, be formed only in individual locations of the housings and/or another attachment for mounting the rotor housing 33 to the stator housing 23 may be provided.

(21) The rotor housing 33 penetrates the container wall 4′ at an opening and is mounted and/or attached to the stator housing 23 in this opening of the container wall 4′. The rotor housing 33 comprises a stationary pin 32, the center line of which coincides with the rotational axis R and which (like the rotor housing 33) is designed to be stationary and non-rotatable. A ball bearing 36, which can rotate around the stationary pin 32 and around the rotational axis R, is disposed around the stationary pin 32. Multiple permanent magnets 31 of the rotor 30, which are able to move around the stationary pin 32 and, in this process, carry out a rotational movement about the rotational axis R, are mounted on the ball bearing 36. The permanent magnets 31 form a rotating part of the rotor 30 to which the stirring shaft 9 is rigidly coupled. Upon rotation of the rotor 30, or more precisely of the permanent magnets 31, about the rotational axis R, the stirring shaft 9 thus also rotates about the rotational axis R.

(22) In an alternative embodiment, the rotor is mounted by way of a different mounting, for example without a pin and with outside bearings, in the rotor housing.

(23) FIG. 3A furthermore shows a magnetic flux MG through opposing coils 21 of the stator 20 and through opposing permanent magnets 31 of the rotor 30. In the activation of the three-phase motor 10 shown in FIG. 3A, the magnetic flux MG thus flows through opposing coils and opposing permanent magnets.

(24) Alternatively, the same three-phase motor 10 can also be activated in such a way that a magnetic flux MN takes place through adjoining coils 21 of the stator 20 and through adjoining permanent magnets 31 of the rotor 30. This activation is shown in the cross-sectional view through the three-phase motor 10 shown in FIG. 3B. The cross-section shown in FIG. 3B is parallel offset from the cross-section shown in FIG. 3A and shows a sectional view through a cutting plane B-B, which is likewise shown in FIG. 2.

(25) By way of a control unit, which is not shown in the figures, the coils 21 of the three-phase motor 10 can be selectively activated as shown in FIG. 3A or as shown in FIG. 3B. Moreover, the control unit can be used to set the current intensity, and thus the force of attraction between the coils 21 and the permanent magnets 31. The shown three-phase motor 10 can be used to drive the stirring shaft 9 mounted in the area making contact with the medium, without a rotating element of the drive mechanism having to be introduced through the bag 4 into the sterile area, for example. The drive mechanism thus does not come in contact with the medium, does not become contaminated, and does not have to be cleaned and/or sterilized for a subsequent process. Furthermore, complex sealing of a rotary union into the area making contact with the medium is eliminated.

(26) As shown in FIGS. 3A and 3B, the magnetic fields M.sub.G and/or M.sub.N can have different designs, and more particularly as a function of the geometric arrangement and electrical activation of the coils 21 and the design of the rotor 30. The arrangement and interconnection may be optimized so as to effectuate a magnetic flux through two adjoining coil magnet pairs or through two opposing coil magnet pairs. Each of the coils 21 is activated in such a way that the rotor 30 is displaced in a desired direction of rotation about the rotational axis R by the generated magnetic field, which is to say the magnetic field thus forms between the next coil pair in the direction of rotation and the next permanent magnets. The rotor 30 synchronously follows the rotating field of the coils 21.

(27) In an alternative embodiment of the rotor, the rotor does not comprise any permanent magnets, but one or more squirrel-cage rotors. A flow of current, which induces a magnetic field in the rotor, is created in the rotor, which is composed of laminated cores comprising short-circuited windings and/or composed of a cast core, by way of a rapidly rotating magnetic field of the coils 21. Due to the force of attraction between the rotating field of the coils of the stator and the induced magnetic field in the rotor, the rotor follows the rotating field. The rotor follows the rotating field asynchronously, which is to say at a lower rotational speed than the rotational speed of the rotating field.

(28) FIG. 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 three-phase motor 10 shown in FIGS. 2, 3A and 3B. The shown cutting plane extends through to the rotational axis R. In the axial three-phase motor 10, the axes of the coils 21 are disposed substantially parallel to the rotational axis R, and the permanent magnets 31 of the rotor 30 are disposed substantially parallel to the rotational axis R. The “orientation of the permanent magnets” shall be understood to mean the orientation of magnetic north to magnetic south. In the embodiment shown in FIG. 4, the magnetic souths are provided exactly above the magnetic norths, and more particularly parallel to the rotational axis R. The three-phase motor 10 is thus designed as what is known as an axial three-phase motor 10.

(29) FIG. 5 shows a radial three-phase motor 11. The radial three-phase motor 11 resembles the axial three-phase motor 10 and comprises several identical or similar components. The cutting plane of the cross-section shown in FIG. 5 includes the rotational axis R. The stator 20 comprises radial coils 21′, the coil axes of which are disposed substantially perpendicular to the rotational axis R. More precisely, the radial coils 21′ are disposed in a circle around the rotational axis R in such a way that the coil axes thereof point substantially perpendicular to the rotational axis R. When current flows through the radial coils 21′, a magnetic field is generated, which is to say a stator magnetic field, which interacts with radial permanent magnets 31′ of the rotor 30. The radial permanent magnets 31′ are also disposed in a substantially circular manner and perpendicularly to the rotational axis R. Either magnetic north or magnetic south points outwardly in the direction of a radial coil 21′.

(30) In the radial three-phase motor 11, the rotor 30 engages completely in a recess of the stator 20, wherein the rotor 30 is mounted at least partially inside of the stator 20. As in the above-described embodiment, a rotational movement of the rotor 30 about the rotational axis R effectuates turning (a rotation) of the stirring shaft 9, to which the rotor 30 is coupled. The rotor 30 is mounted on a rotor mount 35, which has an opening through which the stirring shaft 9 is coupled to the head of the rotor comprising the radial permanent magnets 31′. The rotor mount 35, forming a part of a rotor housing, is connected to the container wall 4′, has a stationary and non-rotatable design, and can form a clamping seat with the stator housing 23.

(31) The clutch between the rotor and the stator can thus be either axial, for example as is the case with the axial three-phase motor 10, which is shown in FIG. 4, or it can be radial, for example as is the case with the radial three-phase motor 10, which is shown in FIG. 5. In both embodiments, the rotor 30, the stirring shafts 9, and in particular the permanent magnets 31 or 31′, which is to say the entire stirring element 3, are disposed inside the container 4 and thus designed to make contact with the medium. The stator housing 23 can have an optimized design for the interconnection of the coils 21 or 21′, and the position of the permanent magnets or squirrel-cage rotors.

(32) Both in the case of the axial three-phase motor and in the case of the radial three-phase motor, the stator housing (not making contact with the medium) may form a clamping connection with the rotor housing (making contact with the medium). The rotor housing 33 is designed to be stationary and non-rotatable and serves as a stationary and non-rotatable mount for the stirring shafts 9 and the permanent magnets 31, 31′ or the squirrel-cage rotor or rotors.

(33) Instead of a clamping connection between the stator housing and the rotor housing, screw joints, magnetic couplings and/or other attachments may be provided. The stirring shaft 9 can be mounted on the driving device 2 on the one hand, and also on a counter mount 7, on the other hand, as shown in FIG. 1. Alternatively, the stirring element 3 can only be mounted on one side, this being the drive-side mount 6. In such an embodiment, the stirring element does not penetrate the container 4 completely, but only protrudes from a container wall of the container 4 into the inside of the container 4. The double mounting, which is to say the mounting on opposing walls of the container 4, however, increases the stability of the stirring shaft during the rotational movement thereof.

LIST OF REFERENCE SIGNS

(34) 1 mixing device 2 driving device 3 stirring element 4 container or bag 4′ container wall 5 stirring appendage 6 drive-side mount 7 counter mount 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 protrusion 30 rotor 31 permanent magnet 31′ radial permanent magnet 32 stationary pin 33 rotor housing 34 clamping insert 35 rotor mount 36 ball bearing R rotational axis M.sub.G magnetic flux through opposing coils M.sub.N magnetic flux through adjoining coils