Centrifuge with cooling system in centrifuge housing

Abstract

A centrifuge (10) having a centrifuge housing, a safety vessel (14) arranged in the centrifuge housing, an interior space (16) at least partially bounded by the safety vessel (14), a rotor arranged in the interior space (16), and a cooling system, arranged in the centrifuge housing, for cooling the interior space (16), having a compressor (22), a condenser (24) and an evaporator (26), which are connected together via lines. The invention is distinguished by the fact that the cooling system has a primary circuit (52) with primary line (29) and a secondary circuit (62) with secondary line (34), wherein the primary circuit (52) comprises the compressor (22), the condenser (24) and the evaporator (26), which is part of a heat exchanger (30), and wherein the secondary circuit (62) flows through the heat exchanger (30), cools the safety vessel (14) and is provided with a pump (32).

Claims

1. A centrifuge (10), comprising: a centrifuge housing (13): a safety vessel (14) arranged in a protective cylinder (18) in said centrifuge housing (13): an interior space (16) partially bounded by said safety vessel (14); a rotor arranged in said interior space (16); a cooling system arranged in said centrifuge housing (13) for cooling said interior space (16); said cooling system has a compressor (22), a condenser (24) and an evaporator (26) which are connected together via lines; said cooling system has a sealed primary circuit (52) with primary lines (29) and a sealed secondary circuit (62) with secondary lines (34); a flammable refrigerant (54) in said sealed primary circuit (52); a non-flammable refrigerant (64) in said sealed secondary circuit (62); said sealed primary circuit (52) comprises said compressor (22), said condenser (24) and said evaporator (26), said evaporator is part of a closed heat exchanger (30); and, said sealed secondary circuit (62) passes through said closed heat exchanger (30), cools said safety vessel (14) and is provided with a pump (32).

2. The centrifuge as claimed in claim 1, further comprising: said primary circuit (52) is arranged underneath said secondary circuit (62) and said safety vessel (14).

3. The centrifuge as claimed in claim 1, further comprising: said primary circuit (52) is mounted in said centrifuge housing (13) so as to be laterally offset relative to said secondary circuit (62).

4. The centrifuge as claimed in claim 3, further comprising: a safety wall (36) is mounted between said primary circuit (52) and said safety vessel (14) to spatially separate these components.

5. The centrifuge as claimed in claim 1, further comprising: at least one additional mass element (44) is provided in said centrifuge housing (13) for stabilizing said centrifuge housing (13).

6. The centrifuge as claimed in claim 1, further comprising: said primary lines (29) are made of a material which is mechanically stronger than the material of said secondary lines (34).

7. The centrifuge as claimed in claim 6, further comprising: predetermined breaking points are provided in said secondary lines (34).

8. The centrifuge as claimed in claim 1, further comprising: said safety vessel (14) is surrounded by said protective cylinder (18) which is separate from said safety vessel (14).

9. The centrifuge as claimed in claim 1, further comprising: dampening and/or insulation material (40) is provided in said primary circuit (52) between said compressor (22), said condenser (24) and said evaporator (26).

10. A centrifuge (10), comprising: a centrifuge housing (13); a safety vessel (14) arranged in a separate protective cylinder (18) in said centrifuge housing (13); an interior space (16) partially bounded by said safety vessel (14); a rotor arranged in said Interior space (16); a cooling system arranged in said centrifuge housing (13) for cooling said interior space (16); said cooling system has a compressor (22), a condenser (24) and an evaporator (26) which are connected together via lines; said cooling system has a sealed primary circuit (52) with primary lines (29) and a sealed secondary circuit (62) with secondary lines (34); a flammable refrigerant (54) in said sealed primary circuit (52); a non-flammable refrigerant (64) in said sealed secondary circuit (62); said safety vessel is surrounded by said separate protective cylinder (18) which runs concentrically around said safety vessel (14); clamping connections (38) horizontality secure said separate protective cylinder (18) to said centrifuge housing; said clamping connections (38) which in the event of a rotor crash will enable said safety vessel (14) to move relative to said centrifuge housing (13); said sealed primary circuit (52) comprises said compressor (22), said condenser (24) and said evaporator (26), said evaporator is part of a closed heat exchanger (30); and, said sealed secondary circuit (62) passes through said closed heat exchanger (30), cools said safety vessel (14) and is provided with a pump (32).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Throughout the description, the claims and the drawings, those terms and associated reference signs are used as are indicated in the list of reference signs which follows below. In the drawings,

(2) FIG. 1 is a schematic perspective view of a centrifuge according to the invention;

(3) FIG. 2 is a schematic graph of the two cooling circuits;

(4) FIG. 3 is a lateral sectional view of the primary circuit of a centrifuge according to the present invention with dampening and insulation elements; and

(5) FIG. 4 is a schematic perspective view of a centrifuge according to the present invention which has a primary circuit arranged underneath the secondary circuit;

DESCRIPTION OF THE INVENTION

(6) FIG. 1 is a schematic perspective view of a centrifuge 10 according to the present invention. For the sake of clarity, the housing is not shown in this drawing; the arrangement of the housing cover 13a and the side walls 13b may be gathered from FIG. 3. A safety vessel 14 of the centrifuge 10 is mounted on a base plate 12 together with a compression refrigeration unit 20. The compression refrigeration unit 20 essentially comprises a compressor 22, a condenser 24, a ventilator 25, a filter dryer 28 and an evaporator 26 that is part of a heat exchanger 30, which components are connected together via primary pipes 29 to thus form a sealed primary circuit 52 (see FIG. 2). A flammable refrigerant 54 flows in the primary pipes 29.

(7) The safety vessel 14 is surrounded by secondary pipes 34 which are only shown to some extent in this drawing and which essentially form a sealed secondary circuit 62 (see FIG. 2). A non-flammable heat transfer medium 64 flows in the secondary pipes 34.

(8) The structure of the primary circuit 52 and the secondary circuit 62 is also illustrated more clearly in the schematic view of FIG. 2.

(9) A protective cylinder 18 runs concentrically around the safety vessel 14 and is more specifically horizontally secured by four clamping elements 38 which are mounted at regular intervals from each other on the base plate 12, along the outer circumference of the protective cylinder 18. However, this perspective view only shows one clamping element 38. In the event of a rotor crash, the protective cylinder 18 will prevent flying rotor parts from being scattered further, which may rupture and penetrate the centrifuge wall and thus inflict major damage there. For additional protection of the primary circuit 52 from penetrating rotor parts in the event of a crash, which may even rupture the protective cylinder 18, a safety wall 36 is mounted on the base plate 12 between the safety vessel 14 and the compression refrigeration unit 20.

(10) The secondary circuit 62 runs through the heat exchanger 30. For this purpose, two openings 34a and 34b are provided in the safety wall 36, with pipes 34 of the secondary circuit 62 extending through each of said openings 34a, 34b. The pipe 34 runs from the safety vessel 14 through the opening 34b to the heat exchanger 30 in which heat is withdrawn from the secondary circuit 62. Mounted between the heat exchanger 30 and the opening 34a, through which the pipe 34 runs back to the safety vessel 14, is a pump 32 for circulating the non-flammable heat transfer medium 64.

(11) FIG. 2 is a schematic view of the principle of the two-circuit cooling of a centrifuge 10 according to the invention. On a cold side 60, there is the secondary circuit 62 in which a non-flammable heat transfer medium 64 circulates. The heat transfer medium 64 is circulated in secondary pipes 34 around a safety vessel 14, thus withdrawing heat from said safety vessel 14. Furthermore, a pump 32 is provided which circulates the heat transfer medium 64.

(12) On the warm side 50, there is the primary circuit 52 in which a flammable refrigerant 54 flows, with the compression refrigeration unit 20 that comprises the compressor 22, the condenser 24, the ventilator 25, the throttle 28 and the evaporator 26, which components are connected together by primary pipes 29.

(13) The evaporator 26 is part of a heat exchanger 30 which also has pipes 34 of the secondary circuit 62 running through it. Consequently, the primary circuit 52 and the secondary circuit 62 are thermally coupled via the heat exchanger 30. In the heat exchanger 30, the non-flammable heat transfer medium 64 from the secondary circuit 62 transfers the heat withdrawn from the safety vessel 14 to the flammable refrigerant 54 in the primary circuit 52. Via the condenser 24, the flammable refrigerant 54 transfers the heat thus transferred to the ambient air 56. The heat delivery is improved by the use of the ventilator 25. Compression refrigeration units are essentially well known so that no further explanations are necessary here.

(14) FIG. 3 is a lateral, partially sectional view of the primary circuit 52 of the centrifuge 10 from the perspective of the secondary circuit 62. As already described with reference to FIG. 1, the compressor 22, the condenser 24 with associated ventilator 25, the filter dryer 28 and the evaporator 26 (not shown here) are connected to each other via primary pipes 29. The primary circuit 52, similar to the secondary circuit 62 not shown in FIG. 3, is surrounded by a rectangular housing 13 which has a base plate 12 at its bottom, a housing cover 13 at its top, and sidewalls 13b, 13c between the base plate 12 and the housing cover 13a. Ventilation slots 24a are provided in the area of sidewall 13c adjacent to the condenser 24.

(15) In the space between the housing 13 and the components of the primary circuit 52 with the largest spatial expansion, i.e. in particular compressor 22, condenser 24, ventilator 25 and evaporator 26 (not shown here), a molding 40 made from rigid foam is provided for insulation and for the purpose of dampening vibrations. The shape of the hard-foam molding 40 is adapted to the housing 13 and—in some parts—to the profile of the above-mentioned components of the primary circuit 52. The hard-foam molding 40 extends horizontally between the sidewalls 13b and 13c along the housing cover 13a, and vertically—in some parts—along the sidewalls 13b and 13c, as well as—in some parts—along the profile of

(16) the above mentioned components of the primary circuit 52. The vertical expansion of the hard-foam molding 40 is adapted to the structural conditions of the primary circuit and chosen such that it can be fitted in easily, surrounds about the upper third of the compressor 22, and at the same time abuts on the top of the aforementioned components of the primary circuit 52. The compressor 22 for example surrounds the hard-foam molding 40 approximately in the upper third of its vertical expansion. Furthermore, ducts 42 are provided in the hard-foam molding 40 in which primary pipes 29 run.

(17) The centrifuge 10 is supported on four feet 46 mounted on the bottom side of the base plate 12 on a surface, with two of said feet 46 being below the primary circuit. For increased stability, a rectangular mass element 44 is also mounted on the bottom side of the base plate 12, roughly at its center.

(18) FIG. 4 is a view of an alternative embodiment of a centrifuge 10 according to the invention, in which a secondary circuit 62 is arranged above a primary circuit 52. For the sake of clarity, no housing is shown in this drawing.

(19) The primary circuit 52 is mounted on a rectangular base plate 70 having two front sides 72 and two longitudinal sides 74. Its structure and function are identical to that of the primary circuit 52 shown in FIG. 1 to 3, so no further explanations are necessary here. Attached to the edges of the base plate 70 by means of screws 88 is a frame 76 which on the one hand serves to mount sidewalls of the housing (not shown here) and on the other hand to stably secure an intermediate base 90 having two front sides 92 and two longitudinal sides 94, on which the secondary circuit 62 is mounted. The frame 76 comprises two rectangular frame parts 78 each having two front sides 80 and two longitudinal sides 82a and 82b which are arranged between the two front sides 72 of the base plate 70 and the two front sides 92 of the intermediate base 90. The longitudinal sides 82a are firmly connected to the base plate 70 by means of screws 88, and the longitudinal sides 82b are firmly connected to the intermediate base 90 by means of screws 88. The frame 76 furthermore comprises two horizontally extending frame elements 84 which are each firmly connected to the base plate 70 at their two longitudinal sides 74 by means of screws 88, as well as four vertical frame elements 86. The vertically extending frame elements 86 extend from the four corners of the base plate 70 to the four corners of the intermediate base 90. For improved stability, the frame elements 86 have two legs 87a and 87b which are perpendicular to each other and which are formed integrally with each other and made of the same material. The legs 87a are each arranged between the front side 72 of the base plate 70 and the front side 92 of the intermediate base 90, and the legs 87b are each arranged between the longitudinal side 74 of the base plate 70 and the longitudinal side 94 of the intermediate base 90. Attached to both front sides 92 of the intermediate base 90—amongst other things for attaching sidewalls of the housing not shown here—are horizontal frame elements 96 and attached to both longitudinal sides 94 are horizontal frame elements 98, by means of screws 88.

(20) As far as structure and function are concerned, the secondary circuit 62 which is arranged on the intermediate base 90 essentially corresponds to the one described with reference to FIG. 1 to 3, for which reason no further explanations are necessary here. Merely the arrangement of the secondary pipes 34 relative to each other has been suitably modified, owing to the vertical arrangement of the primary circuit 52 above the secondary circuit 62. The safety vessel 14 and the protective cylinder 18 surrounding it are supported on a holding device 100 which is firmly connected to the intermediate base 90 and the horizontal frame elements 98 as well as the horizontal frame elements 96. For additional stabilization, supporting struts 102 are provided underneath the intermediate base 90 which extend in parallel to the front sides 92 and are firmly secured to the intermediate base 90 and the horizontal frame elements 98 by means of screws 88.

LIST OF REFERENCE SIGNS

(21) 10 centrifuge 12 baseplate 13 housing 13a housing cover 13b, 13c sidewalls 14 safety vessel 16 interior space 18 protective cylinder 20 compression refrigeration unit 22 compressor 24 condenser 25 ventilator 26 evaporator 28 filter dryer 29 primary pipes 30 heat exchanger 32 pump 34 secondary pipes 34a opening 34b opening 36 safety wall 38 clamping elements 40 hard-foam molding 42 ducts 44 mass element 50 warm side 52 primary circuit 54 flammable refrigerant 56 ambient air 60 cold side 62 secondary circuit 64 non-flammable heat transfer medium 70 base plate 72 front sides 74 longitudinal sides 76 frame 78 frame parts 80 front sides 82a, 82b longitudinal sides 84 horizontally extending frame element 86 vertically extending frame element 88 screws 90 intermediate base 92 front sides 94 longitudinal sides 96 horizontal frame elements 98 horizontal frame elements 100 holding device 102 support struts Q.sub.1 cold side heat flow Q.sub.2 warm side heat flow