JP4581533B2 - Non-contact stirrer - Google Patents

Description

  The present invention relates to a non-contact stirrer that stirs a liquid to be stirred in a non-contact manner.

  Conventionally, a non-contact stirrer by magnetic levitation using a superconducting bulk material has been devised for the purpose of stirring the liquid to be stirred without contact. FIG. 12 shows a conventional non-contact stirrer. According to this non-contact stirrer, as shown in FIG. 12, the superconducting bulk body 1 in the vacuum container 2 is cooled by the refrigerator 3 to be in a superconducting state, and the vacuum container closest to the superconducting bulk body 1 is used. An agitating blade 5 containing a levitating magnet 4 that floats in the vicinity of the surface of 2 is disposed. Then, the superconducting bulk body 1 captures the distribution of the magnetic field generated from the levitated magnet 4. On the other hand, as shown in FIG. 12, an arm-shaped support body 8 extends upward from the stirring blade 5, and a passive magnet 9 is attached to the tip of the support body 8. The long support 8 couples the levitating magnet 4 and the passive magnet 9. In contrast to the passive magnet 9, an active magnet 10 is installed outside the container 7 in order to rotate the passive magnet 9. The active magnet 10 is rotated by the rotation drive mechanism 11. The passive magnet 9 and the active magnet 10 constitute a magnetic rotation transmission mechanism called a magnetic coupling 12 in which permanent magnets are combined. Also, a superconducting bulk body 1 that is closely spaced by a levitated magnet 4 having a stirring blade 5, a vacuum vessel 2 that contains the superconducting bulk body 1, and a refrigerator 1 that cools the superconducting bulk body 1 are magnetically levitated. The means 16 is configured. Note that the vacuum container 2 shown in FIG. 12 is connected to a vacuum pump (not shown) by the vacuum port 14 and has a structure in which the pressure is reduced to provide vacuum insulation. The refrigerator 3 is connected to a helium compressor (not shown) through flexible helium pipes 15a and 15b.

  The operation of the prior art is as follows. As shown in FIG. 12, the levitated magnet 4 magnetically levitated by the superconducting bulk body 1 is magnetically supported in the container 7 without touching the inner wall surface of the container wall 7a of the container 7. Similarly, the passive magnet 9 and the active magnet 10 constituting the magnetic coupling 12 are also supported with a predetermined gap, and the rotational force of the rotation drive mechanism 11 is transmitted to the passive magnet 9 via the active magnet 10. For this reason, the stirring blade 5 is supported in a non-contact manner on the inner wall surface of the container wall 7a of the container 7. Therefore, when stirring the liquid 6 to be stirred, there is an advantage that impurities and the like due to frictional wear occurring at the contact portion between the stirring blade 5 and the container 7 are prevented from being mixed into the liquid 6 to be stirred.

  Here, according to the conventional non-contact stirrer as shown in FIG. 12, the magnetic coupling 12 is installed on the lid 7v of the container 7, and the magnetic levitation means 16 is installed on the bottom of the container 7.

Further, conventionally, as shown in FIG. 13, the levitation magnet 4 forming the magnetic levitation system 13 is arranged in the central region in the radial direction of the stirring blade 5, and the passive magnet 9 forming the magnetic coupling 12 is provided with the stirring blade 5 A non-contact stirrer having a structure arranged on the outer peripheral portion in the radial direction is disclosed (Patent Document 1).
Fig. 2 in Japanese Patent Laid-Open No. 2000-124030

  The non-contact stirrer according to the prior art shown in FIG. 12 has the following problems. As shown in FIG. 12, the magnetic coupling 12 and the magnetic levitation system 13 are disposed to face each other with the container 7 interposed therebetween. Therefore, it is necessary to dispose both the magnetic levitation system 13 and the magnetic coupling 12 by the superconducting bulk body 1 on the outer surfaces 7w and 7x of the container 7 facing each other. For this reason, in the container 7, the support 8 becomes long, the size and weight of the part related to the stirring blade 5 increase, and the support capacity of the superconducting bulk body 1 tends to be exceeded. As a result, the stirring blade 5 is likely to come into contact with the inner wall surface of the container wall 7a of the container 7, and the non-contact performance may not be sufficiently exhibited. Furthermore, it is necessary to manufacture the support 8 each time so as to match the size of the container 7. For this reason, it is difficult to standardize the manufacturing procedure, and the manufacturing cost increases.

  Further, according to the technique according to Patent Document 1 shown in FIG. 13, the levitation magnet 4 forming the magnetic levitation system is arranged in the central region in the radial direction of the stirring blade 5 and the magnetic coupling 12 for power transmission is formed. The passive magnet 9 is disposed on the outer peripheral portion of the stirring blade 5 in the radial direction. In this case, the attractive force of the magnetic coupling 12 is strong, and it is practically difficult for the stirring blade 5 to rotate in a balanced manner. According to the technique according to Patent Document 1, even if the agitating blade 5 is slightly out of balance during the rotation of the agitating blade 5, the agitating blade 5 is inclined to one side, and the peripheral portion of the agitating blade 5 is The frequency of contact with the inner wall surface of the container 7 increases. Thus, with the repulsive force due to magnetic levitation of the superconducting bulk body 1, it is not easy to prevent adsorption by the magnetic coupling 12 located on the outer peripheral portion of the stirring blade 5. Thus, in the technique according to Patent Document 1 in which the magnetic levitation system is arranged in the central region of the stirring blade 5, the contact between the central region of the stirring blade 5 and the inner wall surface of the container 7 does not occur. The frequency at which the outer peripheral portion of 5 or the tip of the stirring blade of the stirring blade 5 contacts the inner wall surface of the container 7 is high.

The present invention has been made in view of the above-described circumstances, and can eliminate the arm-shaped support according to the prior art, which is advantageous in reducing the size and weight. Further, the stirring blade contacts the inner wall surface of the container. It is an object of the present invention to provide a non-contact stirrer that is advantageous in reducing the frequency of occurrence.

The non-contact stirrer according to the present invention is
A non-magnetic container having a storage chamber for storing a liquid to be stirred;
A stirring blade that is disposed inside the storage chamber of the container and has a stirring unit that stirs the liquid to be stirred in the storage chamber, a floating magnet, and a passive magnet;
A superconducting bulk body that is disposed outside the container and forms a magnetic levitation system with a floating magnet of the stirring blade so as to form a gap between the stirring blade and the inner wall surface of the container; A magnetic levitation means having a cooling system to maintain;
An active magnet which is disposed outside the container storage chamber, faces the passive magnet of the stirring blade and forms a magnetic coupling for power transmission with the passive magnet, and a rotational drive system for rotating the active magnet In a non-contact stirrer having a rotation drive mechanism,
The stirring blade has a passive magnet in the central region in the radial direction of the stirring blade, and has a floating magnet outside the passive magnet in the radial direction of the stirring blade ,
The magnetic coupling is disposed on the central region side of the stirring blade in the radial direction of the stirring blade, and the magnetic levitation system is disposed on the outer peripheral region side of the stirring blade in the radial direction of the stirring blade. It is characterized by that.

According to the non-contact stirrer according to the present invention, the stirring blade has the passive magnet in the central region in the radial direction of the stirring blade and the floating magnet on the outer side in the radial direction of the stirring blade . The magnetic coupling for power transmission is arranged on the central region side in the radial direction of the stirring blade, and the magnetic levitation system is arranged on the outer peripheral region side of the magnetic coupling in the stirring blade.

  For this reason, unlike the non-contact stirrer according to the prior art as shown in FIG. 12, the system can be configured from one side of the container. Furthermore, since the support body 8 according to the prior art for coupling the levitating magnet and the passive magnet can be eliminated, the weight and size of the stirring blade are reduced, and the stability of the support performance of the stirring blade is increased. Accordingly, it is advantageous to increase the stirring rotation speed of the stirring blade. Furthermore, it is advantageous to increase the viscosity of the liquid to be stirred contained in the storage chamber of the container, and the degree of freedom in selecting the liquid to be stirred can be expanded.

By the way, contrary to the non-contact stirrer according to the present invention, the levitation magnet 4 forming the magnetic levitation system is arranged in the central region of the agitating blade 5 and the magnetic coupling is formed as in the prior art shown in FIG. It is also conceivable that the passive magnet 9 is configured in the outer peripheral region of the stirring blade 5 . In this case, the attractive force of the magnetic coupling is strong, and it is difficult to smoothly rotate the stirring blade while maintaining the balance. In this case, as described above, during the rotation of the stirring blades 5, alone balance of the stirring blades 5 are slightly broken, the stirring blade is inclined to either contact the periphery of the stirring blades 5 on the inner wall surface of the container The frequency of doing so increases. That is, it is not easy to prevent adsorption by the magnetic coupling located in the outer peripheral region of the stirring blade 5 by the repulsive force due to the magnetic levitation of the superconducting bulk body. As a result, according to the prior art according to Patent Document 1 disposed magnetic levitation system in the center area of the stirring blade 5, the contact with the inner wall surface of the central area and the container in the radial direction of the stirring blade 5 also has not occurred regardless, or contact the outer peripheral portion in the radial direction of the stirring blades 5 on the inner wall surface of the container, or the frequency of the tip of the stirring blade of the stirring blades 5 or in contact with the inner wall surface of the container is increased.

  In this regard, according to the non-contact stirrer according to the present invention, the magnetic coupling for power transmission is disposed on the radial central region side of the stirring blade, and the magnetic levitation system is the outer periphery in the radial direction of the stirring blade. A system arranged on the side of the area is adopted. For this reason, the mutual strong adsorption | suction of a magnetic coupling can be supported by the magnetic levitation system provided in the outer peripheral side of the magnetic coupling. For this reason, during the stirring of the stirring blade, the contact frequency between the radially outer peripheral portion of the stirring blade and the inner wall surface of the container can be reduced. Furthermore, the rotation of the stirring blade can be stabilized with respect to various rotational speeds used and various gaps in which the magnetic coupling functions. For this reason, the stirring blade is effectively prevented from coming into contact with the inner wall surface of the container, and the step-out of the stirring blade is suppressed.

  By the way, the magnetic coupling always exhibits an attractive force in the direction of the rotational axis of the rotational drive system. Therefore, a stress that tends to narrow the distance between the superconducting bulk body and the levitation magnet always acts on the magnetic levitation system. On the other hand, the gap between the superconducting bulk body and the levitating magnet constituting the magnetic levitation system tries to maintain a certain distance so that the magnetic field distribution of the levitating magnet captured by the superconducting bulk body does not change. . Here, it is known that the repulsive force against the stress in the approaching direction is stronger than the resistance force in the separating direction. The repulsive force increases as the gap between the superconducting bulk body and the levitating magnet becomes narrower. Therefore, the repulsive force of the superconducting bulk body works effectively against the movement in the attracting direction in the magnetic coupling, and the displacement of the stirring blade can be effectively suppressed.

According to the non-contact stirrer according to the present invention, the power transmission magnetic coupling is disposed on the radial central region side of the stirring blade, and the magnetic levitation system is on the radial outer peripheral region side of the stirring blade. The method arranged in is adopted. For this reason, the mutual strong adsorption | suction of a magnetic coupling can be supported by the magnetic levitation system provided in the outer peripheral side of the magnetic coupling. Unlike the prior art shown in FIG. 12, a magnetic levitation system and a magnetic coupling are arranged on one side of the stirring vessel. For this reason, the dimension of the container which can be installed is not fundamentally chosen, but it can adapt to the various containers which have a dimension which can contain a stirring blade. Furthermore, unlike the prior art shown in FIG. 12, the support 8 that joins the passive magnet and the levitated magnet can be eliminated, so that the entanglement between the supports 8 can be prevented, and a plurality of stirring blades can be stored in one container. It can be installed indoors, and the stirring performance of the non-contact stirrer can be dramatically improved. In the prior art shown in FIG. 12, when a plurality of stirring blades are installed in the storage chamber of a single container, there is interference between the supports, so the risk of mixing impurities is proportional to the number of installations. In practice, a plurality of stirring blades cannot be installed in one container. In this regard, according to the non-contact stirrer according to the present invention, since the support 8 for coupling the passive magnet and the floating magnet can be eliminated as described above, even if a plurality of stirring blades are attached in one container, Contamination of impurities due to frictional wear is suppressed.

  Furthermore, according to the non-contact stirrer according to the present invention, since the rotation of the stirring blade is stable as described above, the stirring blade is stably supported without being in contact with the inner wall surface of the container. Becomes easy. Thus, since the rotation of the stirring blade in a non-contact state is stabilized, it can be used for the inner wall surface of the container having a gently curved surface, and there may be a step or a groove on the inner wall surface of the container. Thus, the freedom degree of installation of the stirring blade in connection with stirring improves.

  The levitation magnet is arranged in a ring around the passive magnet of the stirring blade, and the direction of the axis of rotation of the active magnet of the magnetic coupling and the magnetization direction of the ring-shaped levitation magnet are in line with each other. it can. Here, the levitation magnet is arranged in a ring shape around the passive magnet of the stirring blade, and the direction of the axis of rotation of the active magnet of the magnetic coupling and the magnetization direction of the ring-shaped levitation magnet are substantially the same. In general, a parallel configuration (corresponding to Example 1) can be employed.

  The levitation magnet is arranged in a ring around the passive magnet of the stirring blade, and the levitation of the ring facing the superconducting bulk body of the magnetic levitation system and the direction of the axis of rotation of the active magnet of the magnetic coupling It is possible to adopt a form in which the magnets are arranged so that their magnetization directions intersect each other. Here, the levitation magnet is arranged in a ring shape around the passive magnet of the stirring blade, and the direction of the axis of rotation of the active magnet of the magnetic coupling and the ring facing the superconducting bulk body of the magnetic levitation system A configuration (corresponding to Example 4) in which the magnetization directions of the magnet-like levitating magnets are arranged so as to be substantially orthogonal to each other can be adopted.

  A superconducting bulk body is generally manufactured by a melt solidification method, and its main component is RE-Ba-Cu-O (RE is Y, La, Nd, Sm, Eu, Gd, Er, Yb, Dy, One or more of Ho). The superconducting bulk body can be synthesized by a solidification method in which a constituent material of the superconducting body is once heated to a melting point or higher and then melted and solidified again to synthesize a RE-Ba-Cu-O-based superconducting bulk body. In this case, the superconducting bulk body can have a structure in which the crystal grains are coarse and the insulating phase is finely dispersed in the superconducting parent phase. Since the finely dispersed insulating phase functions as a pinning point of the magnetic field, a superconducting bulk body having a large trapping magnetic field can be obtained. The superconducting bulk body can contain at least one of Ag, Au, Pt, Rh, and Ce. Here, Ag, Au does not react with the superconducting phase, but precipitates in the superconducting parent phase, and the superconducting bulk of the RE-Ba-Cu-O system, which is a ceramic, does not impair superconducting properties such as the superconducting transition temperature. The mechanical strength of the body can be improved. In addition, in the RE-Ba-Cu-O-based superconducting bulk material containing Pt, Rh, and Ce, the insulating phase is finely dispersed in the superconducting phase that is the parent phase, and exhibits a stronger pinning force. Accordingly, the trapping magnetic field of the superconducting bulk body is increased.

  A first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 schematically shows the concept of the first embodiment. 2 and 3 schematically show the magnetic levitation system 13. 4 and 5 schematically show the stirring blade 5. As shown in FIG. 1, the container 7 has a storage chamber 7r for storing the liquid 6 to be stirred. The container 7 is made of a nonmagnetic material. A non-magnetic material means a material that does not exhibit ferromagnetism. For example, an austenitic stainless steel corresponds to an iron alloy. Stainless steel is slightly magnetized by its plastic working, and this is a non-magnetic category in this embodiment. Other non-magnetic material containers include glass, aluminum and aluminum alloys, copper alloys such as satiety, non-magnetic stainless steel containers enameled, resin containers, and fiber reinforced resin containers.

  The magnetic levitation means 16 includes a superconducting bulk body 1, a ring-shaped vacuum container 2 that accommodates the superconducting bulk body 1, and a refrigerator 3 as a cooling system that cools the superconducting bulk body 1 in the vacuum container 2. And disposed close to the lower wall 7u of the container 7.

The superconducting bulk body 1 is disposed inside the vacuum vessel 2, and vacuum insulation is achieved. The magnetic levitation system 13 includes a plurality of superconducting bulk bodies 1 in the vacuum vessel 2. In this embodiment , six superconducting bulk bodies 1 are arranged around the rotation axis P1 as shown in FIG. 2, but the number is not particularly limited, and may be about three to twelve. These superconducting bulk bodies 1 are fixed to a cold stage 18 formed of a ring-shaped copper plate attached to the freezing unit 17 of the refrigerator 3. The cold stage 18 is fixed in the vacuum vessel 2 so as not to come into contact with the inner wall surface of the vacuum vessel 2 by a heat insulating support material 19 in order to improve heat insulation. The heat insulating support material 19 is made of a material having a low thermal conductivity and a high heat insulating property, for example, a fiber reinforced resin material (FRP). The heat-insulating support material 19 is based on the reaction caused by the weight of the stirring blade 5 and the rotation of the stirring blade 5 while suppressing heat intrusion from the outside of the vacuum vessel 2 to the superconducting bulk body 1 and the cold stage 18 to the minimum. It is set to withstand stress. The refrigeration unit 17 is in contact with a part of the cold stage 18, and the heat of the cold stage 18 is discharged by the refrigerator 3. In the present embodiment, the refrigerator 3 is a GM refrigerator. The helium pipes 15a and 15b are connected to a compressor (not shown), and cool the superconducting bulk body 1 to a low temperature of 40K. In addition to the GM type, the refrigerator 3 can employ a pulse tube refrigerator, a solvay type, a schooling type, or a combination of these.

  In order to keep the inside of the vacuum vessel 2 in a vacuum insulation state, a vacuum pressure reducing port 20 is provided in a part of the vacuum vessel 2. The vacuum pressure reducing port 20 is connected to a vacuum pump system 28 by a flexible or fixed vacuum pipe 21. The vacuum pump system 28 includes a combination of a turbo molecular pump, a cryopump, an oil rotary pump, an oil diffusion pump, a dry pump, and the like. The role of the vacuum pump system 28 is to keep the pressure inside the vacuum vessel 2 in a reduced pressure state (0.1 Pa (Pascal) or less), and good heat insulation cannot be maintained at a pressure higher than this.

  When the temperature region in the vacuum vessel 2 to be cooled is about 30 K or less, the effect of adsorbing the residual gas in the vacuum vessel 2 appears by cooling the freezing unit 17. For this reason, when the vacuum vessel 2 is once depressurized to a high vacuum and then cooled, the inside of the vacuum vessel 2 can be sealed. Therefore, the driving of the vacuum pump system 28 can be stopped. If the driving of the vacuum pump system 28 is stopped, the power consumption required for the vacuum pump system 28 is reduced.

  As shown in FIG. 1, the stirring blade 5 has a ring-shaped levitation magnet 4 built in the stirring blade 5 so as to face the superconducting bulk body 1. The levitating magnet 4 is located above the superconducting bulk body 1. The magnetic pole of the levitation magnet 4 is magnetized to a single pole parallel to the central axis (rotation axis P1) of the levitation magnet 4. Therefore, the upper surface 4a of the levitating magnet 4 is magnetized to one of the S pole and the N pole. The lower surface 4c of the levitation magnet 4 is magnetized to the other of the S pole and the N pole. The levitation magnet 4 may be integrally formed in a continuous ring shape in the stirring blade 5, or may be combined in a ring shape by disposing fan-shaped or trapezoidal magnets intermittently in the circumferential direction. The superconducting bulk body 1 and the levitating magnet 4 constitute a magnetic levitating system 13 for levitating the stirring blade 5.

  On the outer peripheral portion of the stirring blade 5, a stirring blade 22a as a stirring portion having a stirring function is projected. The stirring blade 22a is provided on the outer peripheral portion 5p of the stirring blade 5. The magnetic field generated from the levitating magnet 4 is captured by the superconducting bulk body 1 in the superconducting state. As a result, the levitating magnet 4, and hence the stirring blade 5 incorporating the levitating magnet 4, stably levitates from the superconducting bulk body 1 of the magnetic levitation system 13 through a certain distance interval. As a result, the agitating blade 5 stably floats from the inner wall surface of the storage chamber 7r of the container 7 through a certain distance. Since the stirring blade 5 is stabilized in this way, an advantage that the step-out of the stirring blade 5 during stirring of the stirring blade 5 hardly occurs can be obtained. Here, even if an external force acts on the stirring blade 5 in the radial direction or the axial length direction, the superconducting bulk body 1 returns to its original position due to the magnetic field trap action by the superconducting bulk body 1.

  In order to rotate the stirring blade 5 which is a magnetically levitated system, the following magnetic coupling 12 is configured. Unlike the non-contact stirrer according to the prior art, as shown in FIG. 1, the magnetic coupling 12 is disposed on the same side as the side on which the magnetic levitation system 13 is disposed in the container 7, that is, The magnetic coupling 12 and the magnetic levitation system 13 are arranged on the bottom side of the container 7.

  As shown in FIG. 1, the stirring blade 5 has a passive magnet 9 in the central region in the radial direction of the stirring blade 5. A coupling surface 9c of the passive magnet 9 is disposed on the same side as the levitating magnet 4 constituting the magnetic levitation system 13. Then, the coupling surface 9c of the passive magnet 9 and the coupling surface 10c of the active magnet 10 are close to each other with a certain distance, so that the magnetic coupling 12 that is magnetically coupled is configured.

  As shown in FIG. 1, the rotational drive mechanism 11 includes an active magnet 10 disposed so as to face the passive magnet 9, and a rotational drive system 11 that rotationally drives the active magnet 10 around the rotational axis P1. . The rotation drive system 11 includes a rotating body 11f that holds the active magnet 10, a rotating shaft 11s that is connected to the rotating body 11f and rotates the rotating body 11f integrally, and a motor mechanism that rotates the rotating shaft 11s around the rotation axis P1. And a drive mechanism 11t formed in When the drive mechanism 11t of the rotation drive mechanism 11 is driven to rotate, the active magnet 10 rotates around the rotation axis P1. Here, outside the container 7, the passive magnet 9 and the active magnet 10 are magnetized in multiple poles so that the magnetic poles are alternately different in the circumferential direction in the coupling surfaces 9c and 10c where they are magnetically coupled. . As a result, when the rotation drive mechanism 11 rotates and the active magnet 10 of the rotating body 11f rotates around the rotation axis P1 of the rotation shaft 11s, the passive magnet 9 coupled to the active magnet 10 by magnetic coupling becomes the active magnet 10. Rotate around the rotation axis P1 in the same direction.

  In this case, in the coupling surface 9c of the passive magnet 9 constituting the magnetic coupling 12 and in the coupling surface 10c of the active magnet 10, the different polars are attracted and repelled. Accordingly, the torque of the rotating shaft 11s of the rotation drive mechanism 11 is transmitted to the passive magnet 9 of the stirring blade 5 through the active magnet 10. As a result, the stirring blade 5 containing the passive magnet 9 rotates in the storage chamber 7r of the container 7. As a result, the liquid to be stirred 6 accommodated in the storage chamber 7r of the container 7 can be stirred.

  Further explanation will be added. As shown in FIG. 1, an active magnet 10 is disposed on the outside of the lower wall 7u of the container 7 in the magnetic coupling 12 according to the present embodiment. Since the active magnet 10 rotates around the rotation axis P1, the active magnet 10 and the outer wall surface of the lower wall 7u of the container 7 are arranged so that the active magnet 10 does not contact the outer wall surface of the lower wall 7u of the container 7. The active magnet 10 is arranged so as to form a slight gap.

  At the time of use, the stirring blade 5 is disposed in the container 7 so as to match the position of the active magnet 10 and the position of the magnetic levitation means 16 disposed outside the container 7. In this case, the lid 7v is opened and the stirring blade 5 is inserted into the container 7. If the stirring blade 5 is fixed on the inner surface of the container 7, the horizontal fixing of the stirring blade 5 is not required. However, the stirring blade 5 can be appropriately fixed. At this time, before cooling the superconducting bulk body 1, a spacer (not shown) is interposed between the inner wall surface of the container 7 and the stirring blade 5. The spacer depends on the stirring conditions and the plate thickness of the container 7, but in order to obtain strong support, the gap between the inner wall surface of the container wall 7a of the container 7 and the stirring blade 5 is preferably several millimeters or less. . The distance for inserting the spacer is preferably based on the effective distance of the magnetic coupling 12.

  Next, the vacuum pump system 28 is activated to depressurize the vacuum vessel 2 to make the inside of the vacuum vessel 2 in an adiabatic state. Thereafter, the refrigerator 3 is operated to cool the superconducting bulk body 1 to a superconducting state. Thereby, the distribution of the magnetic field generated from the levitated magnet 4 is captured by the trap function of the superconducting bulk body 1. In such a captured state, even if the levitation magnet 4 moves so as to deviate from the superconducting bulk body 1, the levitation magnet 4 returns to the original position by the trap function of the superconducting bulk body 1.

  When the cooling of the superconducting bulk body 1 to a predetermined temperature is completed, the spacer in the container 7 is removed, and the stirring blade 5 is stably floated. Then, the liquid to be stirred 6 is charged into the storage chamber 7r of the container 7.

  In this state, the active magnet 10, which is the main element of the magnetic coupling 12, is rotated around the rotation axis P1 by driving the rotation drive mechanism 11. As a result, torque is transmitted to the passive magnet 9 of the stirring blade 5, and the stirred liquid 6 in the storage chamber 7 r in the container 7 is stirred by the stirring blade 5. Examples of the liquid to be stirred 6 include liquids that preferably avoid contamination with impurities.

  Next, explanations will be added for FIGS. As shown in FIG. 2, a plurality (six) of superconducting bulk bodies 1 are concentrically spaced apart in the circumferential direction on the upper surface of a ring-shaped copper (metal having good thermal conductivity) cold stage 18. It is installed side by side. Further, the cold stage 18 is fixed to the vacuum vessel 2 by four heat insulating support materials 19 rich in heat insulating properties. The refrigerator 3 is attached under the superconducting bulk body 1 at the right end. When the refrigerator 3 is driven, the superconducting bulk body 1 is cooled to an extremely low temperature via the refrigeration unit 17.

  As shown in FIG. 3, a magnetic shield 23 is provided inside the vacuum vessel 2 and partitions the active magnet 10 and the superconducting bulk body 1. The magnetic shield 23 is made of a soft magnetic iron material having a high magnetic permeability, and extends in a concentric ring shape so as to surround the rotating shaft core P1. The magnetic shield 23 can suppress the magnetic field fluctuation caused by the rotation of the active magnet 10 or the passive magnet 9 from affecting the superconducting bulk body 1.

4 and 5 show the stirring blade 5. As shown in FIGS. 4 and 5, the base 5m of the stirring blade 5 is provided with a stirring blade 22a extending in the radially outward direction around the base 5m. The liquid 6 to be stirred can be stirred by the stirring blade 22a of the stirring blade 5. A magnetic levitation system 13 for the stirring blade 5 is secured by the levitation magnet 4. The amount of rotation and the rotational torque based on the magnetic coupling 12 are ensured by the attraction action of the active magnet 10 and the passive magnet 9. Around the passive magnets 9, the magnetic field variation is a magnetic shield 23 so as not to affect the bulk superconductors 1 is mounted et al this rotation. The magnetic shield 23 extends in a concentric ring shape around the rotation axis P1. The levitation magnet 4 is magnetized in a single pole perpendicular to the surface of the levitation magnet 4, that is, in the axial direction of the ring-shaped levitation magnet 4. Accordingly, the upper surface of the levitating magnet 4 is magnetized to one of the S pole and the N pole, and the lower surface of the levitating magnet 4 is magnetized to the other of the S pole and the N pole.

  As described above, the levitating magnet 4 may be configured by arranging fan-shaped or trapezoidal permanent magnets in a ring shape. A nonmagnetic material is preferable as the material of the base portion 5m constituting the stirring blade 5 incorporating the levitation magnet 4 and the passive magnet 9. Examples of the nonmagnetic material include nonmagnetic austenitic stainless steel, brass, glass, fiber composite resin (FRP), and the like. Nonmagnetic materials include paramagnetic materials. Depending on the type of the liquid to be stirred 6, the magnet material may be corroded, so that the levitated magnet 4 is preferably coated.

  According to the present embodiment, a stable position fixing action between the superconducting bulk body 1 and the levitation magnet 4 can be obtained by the trap action in which the superconducting bulk body 1 traps the distribution of the magnetic field generated from the levitation magnet 4. In this case, a stable support force can be exhibited not only in the vertical direction but also in the horizontal direction with respect to the floating magnet 4 of the stirring blade 5. Therefore, in the non-contact stirrer shown in FIG. 1, the superconducting bulk body 1 is installed not only on the bottom surface of the container 7 but also on the vertical surface and side surface inside the container 7, or the inclined surface or top surface. Thus, the levitating magnet 4 can be levitated.

  As can be understood from the above description, according to this embodiment, unlike the prior art shown in FIG. 12, the magnetic levitation system 13 and the magnetic coupling 12 are arranged on one side of the container 7 in the height direction. For this reason, the dimensions of the container 7 that can be installed are basically not selected, and can be applied to various containers 7 having dimensions capable of containing the stirring blade 5. Furthermore, unlike the prior art shown in FIG. 12, the support 8 that couples the passive magnet 9 and the levitating magnet 4 can be eliminated, so that the entanglement between the supports 8 is prevented, and as a result, a plurality of stirring blades 5 are combined into one. It becomes possible to install in the storage chamber 7r of the container 7, and the stirring performance of the non-contact stirrer can be dramatically improved. In the prior art shown in FIG. 12, when a plurality of stirring blades 5 are installed in the storage chamber of one container 7, there is interference between the supports 8, and therefore the risk of contamination is proportional to the number of installations. In fact, it is impossible to install a plurality of stirring blades 5 in the storage chamber of one container 7. In this regard, according to the present embodiment, since the support 8 can be eliminated as described above, even if a plurality of stirring blades 5 are installed in the storage chamber 7r of one container 7, impurities due to frictional wear are not mixed. It is suppressed.

  Furthermore, according to the present embodiment, since the rotation of the stirring blade 5 is stable as described above, it is easy to stably support the stirring blade 5 without contacting the inner wall surface of the container 7 with an appropriate gap. It becomes. In this way, since the rotation of the stirring blade 5 in a non-contact state is stabilized, it can be used for the inner wall surface of the container 7 having a gently curved surface, and the inner wall surface of the container 7 may have a step or a groove. Thus, the degree of freedom of installation of the stirring blade 5 related to stirring is improved.

  6 and 7 schematically show the concept of the second embodiment. The second embodiment has basically the same configuration and function as the first embodiment. Therefore, it is possible to provide a non-contact stirrer that can eliminate the support, is advantageous in reducing the size and weight, and that reduces the frequency with which the stirring blade 5 contacts the inner wall surface of the container 7. Parts having common functions are denoted by common reference numerals. Hereinafter, a description will be given centering on the differences from the first embodiment. 6 and 7 show the stirring blade 5 of the second embodiment. In the stirring blade 5, instead of the stirring blade 22a, a stirring blade 22b is formed above the stirring blade 5.

  8 and 9 schematically show the concept of the third embodiment. The third embodiment has basically the same configuration and function as the first embodiment. Therefore, it is possible to provide a non-contact stirrer that can eliminate the support, is advantageous in reducing the size and weight, and that reduces the frequency with which the stirring blade 5 contacts the inner wall surface of the container 7. Parts having common functions are denoted by common reference numerals. Hereinafter, a description will be given centering on the differences from the first embodiment. In the first embodiment described above, the stirring blade 22a is provided on the outer peripheral portion of the stirring blade 5, whereas in this embodiment, the stirring blade is not provided on the outer peripheral portion of the stirring blade 5.

  That is, as shown in FIGS. 8 and 9, the passive magnet 9 is disposed in the radial central region of the stirring blade 5, and the ring-shaped floating magnet 4 is disposed in the outer peripheral region of the stirring blade 5 in the radial direction. Are arranged concentrically. A ring-shaped space 5k is formed between the passive magnet 9 and the levitating magnet 4. In the ring-shaped space 5k, a plurality of stirring blades 22c having a stirring function are arranged radially and in a bridged state. According to this embodiment, the diameter DA of the stirring blade 5 is smaller than that in the case of the first embodiment. For this reason, since the foreign matter put into the container 7 and the stirring blade 22c are difficult to contact, the stirring action of the stirring blade 5 is excellent in stability.

  Also in the present embodiment, the stirring blade 5 has the passive magnet 9 in the central region in the radial direction of the stirring blade 5 and the ring-shaped floating magnet 4 on the outer side in the radial direction from the passive magnet 9. ing. Therefore, similarly to Example 1, the magnetic coupling 12 is disposed in the central region in the radial direction of the stirring blade 5, and the magnetic levitation system 13 is disposed in the outer peripheral region in the radial direction of the stirring blade 5. . For this reason, as in Example 1, the stability of the stirring action of the stirring blade 5 is increased. Therefore, there is an advantage that the step-out of the stirring blade 5 is less likely to occur when the stirring blade 5 is stirred. Further, a concentric ring-shaped magnetic shield 23 is provided between the passive magnet 9 and the levitating magnet 4. The magnetic shield 23 can reduce the influence of magnetic field fluctuations on the superconducting bulk body 1. If unnecessary, the magnetic shield 23 may be abolished.

  10 and 11 show the fourth embodiment. The fourth embodiment has basically the same configuration and function as the first embodiment. Therefore, it is possible to provide a non-contact stirrer that can eliminate the support, is advantageous in reducing the size and weight, and that reduces the frequency with which the stirring blade 5 contacts the inner wall surface of the container 7. The present embodiment shows a case where the adsorption / repulsion direction of the magnetic coupling 12 and the levitation direction by the magnetic levitation system 13 intersect each other, that is, a case where they are substantially orthogonal. As shown in FIG. 10, a cup-shaped container 24 is integrally and concentrically attached to the lower part of the container 7 having the storage chamber 7r. The container chamber 24r of the cup-shaped container 24 communicates with the storage chamber 7r of the container 7. Most of the stirring blade 5 enters the container chamber 24r of the cup-shaped container 24.

  A stirring blade 22d as a stirring portion provided in the stirring blade 5 protrudes upward along the rotation axis P1 from the upper surface portion of the stirring blade 5. That is, the stirring blade 22d of the stirring blade 5 protrudes upward from the container chamber 24r of the cup-shaped container 24 toward the storage chamber 7r of the container 7 via the extending portion 5w, and is accommodated inside the storage chamber 7r. .

  According to the present embodiment, the levitating magnet 4 has the inner peripheral surface 4i and the outer peripheral surface 4p facing each other. The inner peripheral surface 4i of the levitation magnet 4 is magnetized to one of the S pole and the N pole. The outer peripheral surface 4p of the levitation magnet 4 is magnetized to the other of the S pole and the N pole.

  Therefore, as shown in FIG. 10, the direction of the rotation axis of the active magnet 10 constituting the magnetic coupling 12 (the direction in which the rotation axis P1 extends) and the superconducting bulk body 1 constituting the magnetic levitation system 13 are opposed. The magnets are arranged so that the magnetization directions of the ring-shaped levitating magnets 4 intersect, that is, substantially perpendicular to each other.

  As shown in FIG. 10, a plurality of superconducting bulk bodies 1 are arranged at intervals on the inner peripheral surface 18i of a cold stage 18 made of a ring made of copper (good heat transfer material) along the circumferential direction thereof. ing. The refrigeration unit 17 that exhibits a cooling function is attached in contact with the outer peripheral surface 18p of the ring-shaped cold stage 18. When the refrigerator 3 is operated, heat is discharged from the freezing unit 17 toward the refrigerator 3, the cold stage 18 is cooled, and the superconducting bulk body 1 is thereby cooled. Note that the heat insulating support material 19 rich in heat insulating properties is applied to the lower surface of the cold stage 18 so as to support the cold stage 18 in the vacuum vessel 2.

  As shown in FIG. 11, the levitating magnet 4 is built in the stirring blade 5. The levitation magnet 4 has a cylindrical shape that coaxially makes one round of the shaft core of the extending portion 5w that forms a shaft core shape, and is attached to the outer peripheral side of the passive magnet 9 so as to surround it. As shown in FIGS. 10 and 11, a magnetic shield 23 is provided in a ring shape substantially coaxially on the inner peripheral side of the levitating magnet 4. It is suppressed by the magnetic shield 23 that the magnetic field fluctuation caused by the rotation of the magnetic coupling 12 is transmitted to the superconducting bulk body 1.

  In the configuration shown in FIGS. 10 and 11, when the superconducting bulk body 1 is cooled, the distribution of the magnetic field generated by the levitated magnet 4 is captured by the magnetic field trap function of the superconducting bulk body 1. For this reason, the levitated magnet 4 is stably adsorbed to the superconducting bulk body 1 leaving almost the original gap, and the position of the levitating magnet 4 is basically fixed by the superconducting bulk body 1. The passive magnet 9 and the active magnet 10 constitute a magnetic coupling 12. The magnetic coupling 12 transmits rotational torque from the active magnet 10 to the passive magnet 9. Even if the active magnet 10 and the active magnet 9 try to attract each other, the magnetic levitation system 13 composed of the superconducting bulk body 1 and the levitation magnet 4 acts so as not to change the relative position by the magnetic field trap function based on the superconducting bulk body 1. . For this reason, the stirring blade 5 during the rotating stirring is only slightly lowered and shifted, and the stirring blade 5 can continue the stirring operation without touching the inner wall surface of the cup-shaped container 24. In this manner, the liquid 6 to be stirred can be stirred by the stirring blade 5 magnetically levitated with respect to the container 7. It is possible to provide a new non-contact stirrer in which mixing of impurities that has occurred in the conventional stirring operation by the contact method is suppressed.

  Here, the magnetic pole distribution in the magnetic coupling 12 basically has a multipolar structure, and a plurality of pairs of N poles or S poles are alternately magnetized in the circumferential direction. On the other hand, the levitation magnet 4 disposed facing the superconducting bulk body 1 is magnetized in a single pole in the plane facing the superconducting bulk body 1. That is, the inner peripheral surface 4i of the levitation magnet 4 is magnetized to one of the N pole and the S pole, and the outer peripheral surface 4p of the levitation magnet 4 is magnetized to the other of the N pole and the S pole. Yes.

  According to the present embodiment, the magnetic coupling 12 and the magnetic levitation system 13 can be disposed substantially closer to each other than the conventional example. For this reason, it is preferable to avoid magnetic interference between the passive magnet 9 and the levitating magnet 4. Therefore, in order to avoid magnetic interference between the passive magnet 9 and the levitating magnet 4, it is preferable to use the magnetic shield 23 shown in FIG. The magnetic shield 23 improves the uniformity of the magnetic field radiated from the surface of the levitation magnet 4, and substantially suppresses the fluctuation of the magnetic field applied to the superconducting bulk body 1. This leads to effective suppression of the temperature rise of the superconducting bulk body 1 during operation, and can contribute to size reduction, energy saving, and cost reduction by reducing the output of the refrigerator.

  By the way, magnetic levitation using a superconducting bulk body is used for power applications such as a magnetic shield flywheel power storage device. In this case, it is a flywheel rotation that requires an extremely high speed of several tens of thousands of rotations per minute. On the other hand, the rotation speed of the stirring blade 5 of this embodiment is much lower than this, and is several tens to several thousand rotations per minute. In flywheel rotation that requires extremely high speed rotation of several tens of thousands of rotations per minute, slight magnetic field fluctuations lead to temperature rise and loss of the superconducting bulk body 1. In this embodiment, because of this much lower rotation, the restriction on the uniformity of the magnetic field distribution of the levitating magnet 4 may be slow. Therefore, a magnetic shield that is simply installed can exhibit a sufficient effect.

  The non-contact stirrer according to the present invention is a field where there is a strict requirement for preventing contamination of foreign substances and impurities in the stirring process, for example, pharmaceuticals, resists for semiconductors that do not allow impurities to be mixed, chemical plants that handle hazardous materials, sealed systems such as high pressure or vacuum It is used in chemical plants and nuclear reaction plants used in Japan.

1 is a cross-sectional view schematically showing a unipolar non-contact stirrer according to Example 1. FIG. FIG. 3 is a plan view schematically showing a superconducting bulk body of a magnetic levitation system of a unipolar non-contact stirrer and an active magnet of a magnetic coupling according to the first embodiment. 1 is a cross-sectional view schematically showing a superconducting bulk body of a magnetic levitation system and an active magnet of a magnetic coupling in a unipolar non-contact stirrer according to Example 1. FIG. 1 is a cross-sectional view schematically showing a stirring blade of a unipolar non-contact stirrer according to Example 1. FIG. 1 is a plan view schematically showing a stirring blade of a unipolar non-contact stirrer according to Example 1. FIG. FIG. 4 is a cross-sectional view schematically showing a stirring blade of a unipolar non-contact stirrer according to the second embodiment. FIG. 6 is a plan view schematically showing a stirring blade of a unipolar non-contact stirrer according to the second embodiment. 6 is a cross-sectional view schematically showing a stirring blade of a unipolar non-contact stirrer according to Example 3. FIG. 6 is a plan view schematically showing a stirring blade of a unipolar non-contact stirrer according to Example 3. FIG. 6 is a cross-sectional view schematically showing a stirring blade of a unipolar non-contact stirrer according to Example 4. FIG. FIG. 6 is a cross-sectional view schematically showing a state where the stirring blade is disposed in the container according to the fourth embodiment. It is sectional drawing which shows the state which concerns on a prior art and is using the unipolar non-contact stirrer. It is sectional drawing which shows typically the state which concerns on another prior art and is using the unipolar non-contact stirrer.

  1 is a superconducting bulk body, 2 is a vacuum container, 3 is a refrigerator (cooling system), 4 is a floating magnet, 5 is a stirring blade, 6 is a liquid to be stirred, 7 is a container, 7a is a container wall, 9 is a passive magnet, 10 is an active magnet, 11 is a rotary drive mechanism, 12 is a magnetic coupling, 13 is a magnetic levitation system, 14 is a vacuum port, 15a is a helium pipe, 15b is a helium pipe, 16 is a magnetic levitation means, 17 is a freezing unit, 18 Is a cold stage, 19 is a heat insulating support material, 20 is a vacuum pressure reducing port, 21 is a vacuum pipe, 22a is a stirring blade (stirring section), 23 is a magnetic shield, and 24 is a cup-shaped container.

Claims (4)

A non-magnetic container having a storage chamber for storing the liquid to be stirred;
A stirring blade that is disposed inside the storage chamber of the container and has a stirring unit that stirs the liquid to be stirred in the storage chamber, a floating magnet, and a passive magnet;
A superconducting bulk body that is disposed outside the container and forms a magnetic levitation system with the levitation magnet of the stirring blade so as to form a gap between the stirring blade and the inner wall surface of the container; A magnetic levitation means having a cooling system for maintaining the bulk body at a low temperature;
It is disposed outside of the storage chamber of the container, an active magnet constituting a magnetic coupling for power transmission between with the passive magnet facing said passive magnet of the stirring blade, rotating the active magnet In a non-contact stirrer comprising a rotation drive mechanism having a rotation drive system,
The stirring blade has a passive magnet in the central region in the radial direction of the stirring blade, and has a floating magnet on the outer side in the radial direction of the stirring blade than the passive magnet,
The magnetic coupling is disposed on the central region side of the stirring blade in the radial direction of the stirring blade, and the magnetic levitation system is more than the magnetic coupling in the radial direction of the stirring blade in the stirring blade. A non-contact stirrer that is disposed on the outer peripheral region side. According to claim 1, wherein the floating magnets are arranged in a ring around said passive magnet of the stirring blade, and the direction of the rotational axis of said active magnet of the magnetic Kappungu, ring of said floating A non-contact stirrer characterized in that the magnetizing directions of the magnets are substantially parallel to each other. According to claim 1, wherein the floating magnets are disposed about a ring-shaped said passive magnet of the stirring blade, and the direction of the rotational axis of said active magnet of the magnetic coupling, the magnetic levitation system contactless agitator that characterized that the magnetization direction of the ring-shaped the floating magnet facing the superconductive bulk body are arranged substantially orthogonal to each other. 4. The magnetic shield according to claim 1, wherein a magnetic shield is provided around the passive magnet in the stirring blade to suppress the magnetic field fluctuation caused by the rotation of the stirring blade from affecting the superconducting bulk body. Concentric circles are provided,
  The non-contact stirrer characterized by the magnetic shield which partitions off the said active magnet and the said superconducting bulk body in the said rotational drive mechanism concentrically with respect to the said active magnet.

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