Centrifuge refrigeration via magnetocaloric system

Abstract

A centrifuge (10) having a safety vessel (30) with a vessel wall (32), a rotor (17), which is arranged in the safety vessel (30) and is connected via a drive shaft (20) to a drive device (22), wherein at least the drive shaft (20) extends through the safety vessel (30), a cooling system for cooling an interior space (31) of the safety vessel (30), which comprises a heat transfer medium (19) for taking up heat from the safety vessel (30), a refrigerating unit (12) and conducting pipelines (18) for the heat transfer medium (19). The invention is distinguished by the fact that the refrigerating unit (12) is based on the magnetocaloric effect, and the interior space (31) of the safety vessel (30) is cooled by a first cooling circuit (111), the magnetocaloric effect of the refrigerating unit (12) extracts heat from the heat transfer medium (19) of the first cooling circuit (111) and feeds the heat to a second cooling circuit (113).

Claims

1. A centrifuge (10), comprising: a cylindrical safety vessel (30) includes a cylindrical vessel wall (32); said cylindrical vessel wall (32) includes an interior wall (40) and an exterior wall (44), said interior wall (40) and said exterior wall (44) of said cylindrical safety vessel form an unimpeded cylindrical intermediate space (48); said cylindrical safety vessel (30) includes an interior space (31); a rotor (17) is arranged in said interior space (31) of said cylindrical safety vessel (30), said rotor is connected via a drive shaft (20) to a drive device (22); said drive shaft (20) extends through said cylindrical safety vessel (30) to rotate said rotor; said interior wall (40) of said cylindrical safety vessel faces said rotor (17); said interior wall (40) being in contact with said interior space (31), and heat is generated by said rotating rotor in said interior space (31); a magnetocaloric refrigeration unit (102); a first fluid passageway through said magnetocaloric refrigeration unit (102) and a second fluid passageway through said magnetocaloric refrigeration unit (102); a first cooling circuit (111); a first heat transfer medium (19) resides in said first cooling circuit (111); said first cooling circuit includes said unimpeded cylindrical intermediate space (48) of said cylindrical safety vessel and said first cooling circuit includes said first fluid passageway through said magnetocaloric refrigeration unit (102); said first cooling circuit includes a first set of low pressure lines (111) for an operating pressure of up to 3 bar; said first set of low pressure lines of said first cooling circuit (111) being interconnected with said unimpeded cylindrical intermediate space (48) of said cylindrical safety vessel and said low pressure lines of said first cooling circuit (111) being interconnected with said first fluid passageway of said magnetocaloric refrigeration unit; said first heat transfer medium in direct contact with said interior wall (40) and said exterior wall (44) of said cylindrical safety vessel, and heat is transferred from said interior space (31) through said interior wall of said cylindrical safety vessel and to said first heat transfer medium; a first pump (14a) for pumping said first heat transfer medium (19) through said first set of low pressure lines (111), said unimpeded cylindrical intermediate space (48) of said cylindrical safety vessel, and said first fluid passageway of said magnetocaloric refrigeration unit; a second cooling circuit (113); said second cooling circuit includes a second set of low pressure lines (113) for an operating pressure of up to 3 bar; a heat exchanger in said second cooling circuit (113); a second heat transfer medium resides in said second cooling circuit (113); said second set of low pressure lines (113) interconnected with said heat exchanger and with said second fluid passageway of said magnetocaloric refrigeration unit; a second pump (14b) for pumping said second heat transfer medium through said second set of low pressure lines (113), said heat exchanger (106) and said second fluid passageway of said magnetocaloric refrigeration unit (102); said magnetocaloric refrigeration unit extracts heat from said first heat transfer medium (19) of said first cooling circuit as it passes through said first fluid passageway of said magnetocaloric refrigeration unit (102) and feeds said heat to second heat transfer medium in said second fluid passageway of said magnetocaloric refrigeration unit; and, said second heat transfer medium passes through said heat exchanger (106) thereby releasing heat to the ambient surroundings.

2. The centrifuge as claimed in claim 1, characterized in that cooling water is used as one of said first or second heat transfer mediums (19), said cooling water contains additives selected from the group consisting of salt and alcohol which act to lower the freezing point.

3. The centrifuge as claimed in claim 1, characterized in that a control or regulating unit (16) is provided to control said magnetocaloric refrigerating unit (12) and thus to adjust the temperature of said interior space (31) of said cylindrical safety vessel (30).

4. The centrifuge as claimed in claim 1, characterized in that said first heat transfer medium (19) is concentrically guided about a central axis in (Y) of said cylindrical safety vessel (30).

5. The centrifuge as claimed in claim 1, characterized in that said interior wall (40) is an interior vessel and said exterior wall (44) is an exterior vessel, and that said interior and exterior vessels are arranged concentrically to one another, with said interior and exterior vessels being matched to each other in proportion so as to obtain a uniform spacing between said interior wall (40) and said exterior wall (44).

6. The centrifuge as claimed in claim 1, characterized in that said first cooling circuit is incorporated into the material of said cylindrical vessel wall (32) of the cylindrical safety vessel (30).

7. The centrifuge as claimed in claim 1, characterized, in that: said cylindrical safety vessel (30) includes a bottom (38); a feed line (54) of said first heat transfer medium (19) is connected to said unimpeded intermediate space (48) of said cylindrical safety vessel (30) and a discharge line (56) of said first heat transfer medium (19) is connected to said unimpeded intermediate space (48).

8. A centrifuge (10), comprising; a cylindrical safety vessel (30) includes a cylindrical vessel wall (32); said cylindrical safety vessel (30) and said cylindrical vessel wall (32) include a vertical central axis (Y); said cylindrical vessel wall includes vertical cooling ducts therein parallel to said vertical central axis and being circumferentially arranged about said cylindrical safety vessel; said cylindrical safety vessel (30) includes an interior space (31); a rotor (17) is arranged in said interior space (31) of said cylindrical safety vessel (30), said rotor is connected via a drive shaft (20) to a drive device (22); said drive shaft (20) extends through said cylindrical safety vessel (30); a magnetocaloric refrigeration unit (102); a first fluid passageway through said magnetocaloric refrigeration unit (102) and a second fluid passageway through said magnetocaloric refrigeration unit (102); a first cooling circuit (111); a first heat transfer medium (19) resides in said first cooling circuit (111); said first cooling circuit includes said vertical cooling ducts (60) of said cylindrical safety vessel and said first cooling circuit includes said first fluid passageway through said magnetocaloric refrigeration unit (102); said first cooling circuit includes a first set of low pressure lines (111) for an operating pressure of up to 3 bar; said first set of low pressure lines of said first cooling circuit (111) interconnected with said vertical cooling ducts of said cylindrical safety vessel and said low pressure lines of said first cooling circuit (111) interconnected with said first fluid passageway of said magnetocaloric refrigeration unit; said first heat transfer medium in direct contact with said vertical cooling ducts, and heat is transferred from said interior space (31) through said interior wall of said cylindrical safety vessel and to said first heat transfer medium; a first pump (14a) for pumping said first heat transfer medium (19) through said first set of low pressure lines (111), said vertical cooling ducts (60) of said cylindrical safety vessel, and said first fluid passageway of said magnetocaloric refrigeration unit; a second cooling circuit (113); said second cooling circuit includes a second set of low pressure lines (113) for an operating pressure of up to 3 bar; said second cooling circuit includes a heat exchanger (106); a second heat transfer medium resides in said second cooling circuit (113); said second set of low pressure lines (113) interconnected with said heat exchanger and with said second fluid passageway of said magnetocaloric refrigeration unit; a second pump (14b) for pumping said second heat transfer medium through said second set of low pressure lines (113), said heat exchanger (106) and said second fluid passageway of said magnetocaloric refrigeration unit (102); said magnetocaloric refrigeration unit extracts heat from said first heat transfer medium (19) of said first cooling circuit as it passes through said first fluid passageway of said magnetocaloric refrigeration unit (102) and feeds said heat to second heat transfer medium in said second fluid passageway of said magnetocaloric refrigeration unit; and, said second heat transfer medium passes through said heat exchanger (106) thereby releasing heat to the ambient surroundings.

9. The centrifuge as claimed in claim 8, characterized in that an annular collector duct (64) for said vertical cooling ducts extends in one plane to a discharge line (56) of said first heat transfer medium.

10. The centrifuge as claimed in claim 8, characterized in that an annular manifold (62)) for said vertical cooling ducts extends in one plane from a feed line (54) of said first heat transfer medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings,

(2) FIG. 1 is a schematic perspective view of a centrifuge of the invention having a magnetocaloric refrigerating unit;

(3) FIG. 2 is a schematic graph of the magnetocaloric refrigeration principle;

(4) FIG. 3 is a lateral sectional view of the safety vessel of a centrifuge of the present invention;

(5) FIG. 4 is a lateral sectional view of the safety vessel of another centrifuge of the present invention;

(6) FIG. 5 is a partial view of the safety vessel of FIG. 4 in cross-section;

(7) FIG. 6 is a partial view of the safety vessel of FIG. 4 in top view, and

(8) FIG. 7 is a lateral sectional view of the safety vessel of a centrifuge of the present invention with a cooled lid and motor cooling.

DESCRIPTION OF THE INVENTION

(9) The view of FIG. 1 is a schematic perspective view of a centrifuge 10 of the present invention having a magnetocaloric refrigerating unit 12 and provides an overview of the basic structure.

(10) A safety vessel 30 of the centrifuge 10 is mounted on a base plate 26 together with the magnetocaloric refrigerating unit 12. The magnetocaloric refrigerating unit 12 essentially comprises a cooling aggregate 13 having a stator mounted therein which is not shown in the drawings, a heat exchanger 15, a pump device (not shown) and a regulating unit 16. Heat transfer medium 19 flows through a system of conducting means 18 in a first cooling circuit 111 between the magnetocaloric refrigerating unit 12 and the safety vessel 30. The first cooling circuit 111 of the heat transfer medium 19 will be explained in more detail with reference to the embodiments shown in the figures which follow.

(11) The safety vessel 30 has a vessel wall 32 with an interior space 31, an interior 34, an exterior 36 and a vessel bottom 38. Conducting means 18 for the heat transfer medium 19 are provided for cooling the interior space 31 of the safety vessel 30, which conducting means 18 are not shown in FIG. 1 and whose various embodiments according to the present invention will be explained with reference to the figures which follow. A drive shaft 20 extends through the vessel bottom 38 along a central axis Y of the safety vessel 30, via which a rotor 17, which is not shown in the drawings for reasons of clarity, is connected to a drive device 22 which is arranged below the safety vessel 30 and not visible from this perspective. The safety vessel 30 is mounted on the base plate 26 via four fastening struts 24, of which only two can be seen in this perspective view.

(12) FIG. 2 is a schematic view of the known principle of the magnetocaloric cooling of a centrifuge 100. On a cold side 110, heat transfer medium 19 circulates in said first cooling circuit 111the cold side 110from which heat is extracted when said magnetocaloric material is periodically exposed to a magnetic field in the cooling aggregate 13 and heats up. As the magnetocaloric material leaves the magnetic field, it will transfer the stored heat to the heat transfer medium 19 of a second cooling circuit 113the warm side 112. Included in the second cooling circuit 113 is a heat exchanger 106 which gives off the heat to the ambient air. The heat delivery is improved by the use of a ventilator 104. Provided in the first cooling circuit 111 is a pump 14a, and provided in the second cooling circuit 113 is a pump 14b which are each used to convey the heat transfer medium 19. Magnetocaloric cooling units are basically known, for which reason a more detailed explanation is not considered necessary here.

(13) FIG. 3 is a lateral sectional view of the safety vessel 30 of a centrifuge 10 of the present invention. The vessel wall 32 of the safety vessel 30 is of a double-wall design having an interior wall 40 which has an exterior 42 that faces away from the interior space 31 of the safety vessel 30 and an exterior wall 44 which has an exterior 46 that faces away from the interior space of the safety vessel 30. The double wall design of the vessel wall 32 serves as a conducting means 18 for the heat transfer medium 19 in the safety vessel 30. An unimpeded intermediate space 48 between the exterior 42 of the interior wall 40 and the interior 46 of the exterior wall 44 extends from a first end portion 50 at the upper end of the vessel wall 32 to a second end portion 52 below the vessel bottom 38 and is used for containing the heat transfer medium 19. The first end portion 50 of the intermediate space 48 is provided with a seal 51, and the second end portion 52 of the intermediate space 48 is provided with a seal 53 so as to prevent heat transfer medium 19 from escaping from the intermediate space 48 in an uncontrolled manner.

(14) Via conducting means 18, the heat transfer medium 19 previously cooled in the magnetocaloric refrigerating unit 12 in the manner described above flows to a feed line 54 provided in a first end portion below the seal 51 which feed line 54 feeds the medium 19 into the intermediate space 48. In the intermediate space 48, the heat transfer medium 19 circulates concentrically around the central axis Y of the safety vessel 30, thereby cooling especially the interior wall 40 through direct surface contact with the exterior 42 of the latter. Finally, the heat transfer medium 19 exits the intermediate space 48 via a discharge line 56 which then feeds it back to the magnetocaloric refrigerating unit 12. Insulation 58 is provided around the safety vessel and rests against the exterior of the exterior wall 44 and is only penetrated by the feed line 54, the discharge line 56 and the drive device 22 which latter extends into the safety vessel 30 through the vessel bottom 38.

(15) For enhanced control of the flow of the heat transfer medium 19, it is also possible to provide flow directing elements in the intermediate space 48 between the interior wall 40 and the exterior wall 44. Furthermore, it is also conceivable to position the interior wall 40 and the exterior wall 44 without any space between them, and to form the conducting means 18 in the safety vessel 30 by mutually associated recesses in the interior wall 40 and the exterior wall 44.

(16) FIG. 4 is a lateral sectional view of the safety vessel 30 of another centrifuge 10 of the present invention. In this embodiment, the vessel wall 32 has vertical circumferential cooling ducts 60 through which the heat transfer medium 19 flows, thereby extracting heat from the vessel wall 32. For distributing the heat transfer medium 19, which is conveyed from the refrigerating unit 12 to the vessel wall 32 via pipelines 18 and the feed line 54, to the individual cooling ducts 60, the vessel wall 32 has an annular manifold 62 which, from a vertical perspective, is mounted on the level of the feed line 54. Likewise, from a vertical perspective, a collector duct 64 is provided on the level of the discharge line 56, which collects the heat transfer medium 19 after it has passed through the cooling ducts 60 and conveys it to the discharge line 56. From the discharge line 56, the heat transfer medium 19 then flows back to the refrigerating unit 12.

(17) For further clarification, the arrangement of the cooling ducts 60, the manifold 62 and the collector duct 64 is shown in more detail in the views of FIGS. 5 and 6. Also, it is possible to reverse the arrangement of the feed line 54 and the discharge line 56 and thus also the functions of the manifold 62 and of the collector duct 64, so that the heat transfer medium 19 will then flow along the safety vessel 30 from bottom to top, instead of from top to bottom.

(18) FIG. 5 is a lateral sectional view of the safety vessel 30 of FIG. 4. FIG. 6 is a top view of the safety vessel 30, illustrating the arrangement of the cooling ducts 60 in the vessel wall 32 as well as the manifold.

(19) FIG. 7 is a view of a safety vessel 30 of another embodiment of a centrifuge 10 of the invention, which has a cooling device. Provided on a drive device 22, which is mounted concentrically relative to a central axis Y of the safety vessel 30 and which in parts extends through a vessel bottom 38, is a cover hood 72 which is likewise mounted concentrically relative to the central axis Y of the safety vessel 30 and on which flexible cooling pipes 74 are mounted. The diameter of the cover hood 72 tapers from the side adjacent to the vessel bottom 38 towards the top, to the side remote from the vessel bottom 38. The cooling pipes 74 are connected to the magnetocaloric refrigerating unit via flexible feed and discharge lines not shown in this Figure.

(20) Instead of the cover hood 72, it is also conceivable to provide conducting means for the heat transfer medium 19 which are incorporated in the drive device 22 and connected to the refrigerating unit.

(21) Above the cover hood 76, a rotor 17 is connected to the drive device 22 via a drive shaft 20.

(22) For closing the safety vessel 30, a centrifuge lid 72 is provided on the side opposite the vessel bottom 38. Mounted on the exterior 74 of this lid 72 which faces away from the interior of the safety vessel 30 are cooling ducts 80 which are connected to the magnetocaloric refrigerating unit via feed and discharge lines not shown in this Figure. In this way, the safety vessel 30 is cooled both by the cover hood 72 in the area of the vessel bottom 38, and by the centrifuge lid 76 located above the rotor 17.

LIST OF REFERENCE SIGNS

(23) 10 centrifuge 12 magnetocaloric refrigerating unit 13 cooling aggregate 14 pump device 14a pumpfirst cooling circuit 14b pumpsecond cooling circuit 15 heat exchanger 16 regulating unit 17 rotor 18 conducting means 19 heat transfer medium 20 drive shaft 22 drive device 24 fastening struts 26 base plate 30 safety vessel 31 safety vessel interior space 32 vessel wall 34 interior 36 exterior 38 vessel bottom 40 interior wall 42 exterior 44 exterior wall 48 intermediate space 50 first end portion 51 seal 52 second end portion 53 seal 54 feed line 56 discharge line 58 insulation 60 cooling ducts 62 manifold 64 collector duct 66 heat exchanger 66a,b heat exchanger plates 68 cooling ducts 72 cover hood 74 cooling pipes 76 centrifuge lid 78 exterior 80 cooling ducts 100 centrifuge 102 cooling aggregate 104 ventilator 106 heat exchanger 110 cold side 111 first cooling circuit 112 warm side 113 second cooling circuit 114 ambient air Y central axis Q.sub.1 cold side heat flow Q.sub.2 warm side heat flow