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US-20260124624-A1 - Centrifuge with flammable temperature control medium

US20260124624A1US 20260124624 A1US20260124624 A1US 20260124624A1US-20260124624-A1

Abstract

A centrifuge ( 10 ) includes a flammable temperature-control medium. The centrifuge has a very simple design and nevertheless offers sufficient protection against ignition of the flammable temperature-control medium in the event of a crash, but also at standstill and during the course of operation. To this end, a first section ( 42 ) of the temperature-control media line ( 40 ), which is arranged in the area of potential electrical or electronic ignition sources for the flammable temperature-control medium, has no connection points ( 114 ).

Inventors

  • Alexandra Brisch

Assignees

  • EPPENDORF SE

Dates

Publication Date
20260507
Application Date
20250912
Priority Date
20241107

Claims (16)

  1. 1 . A centrifuge ( 10 ; 150 ), comprising: a centrifuge container ( 36 ; 172 ) for receiving a centrifuge rotor; a centrifuge motor ( 38 ; 174 ) for driving the centrifuge rotor; a cooling system with an evaporator ( 94 ; 176 ) and a compressor ( 46 ; 184 ) for temperature-controlling the centrifuge rotor; and a housing ( 12 ; 152 ) in which the centrifuge container ( 36 ; 172 ), the centrifuge rotor, and the cooling system are housed, wherein the housing ( 12 ; 152 ) comprises a housing bottom ( 20 ; 160 ), a housing wall ( 14 , 18 , 18 a , 19 ; 154 , 158 ), and a cover ( 24 ), wherein the cooling system includes a flammable refrigerant which is routed in a refrigerant line ( 42 ; 178 ), wherein a first section ( 40 ; 176 ) of the refrigerant line ( 42 ; 178 ) is arranged in an area of potential electrical or electronic ignition sources, wherein a second section ( 52 ; 192 ) of the refrigerant line ( 42 ; 178 ) is not arranged in the area of potential electrical or electronic ignition sources, and wherein the first section ( 40 ; 176 ) does not include connection points.
  2. 2 . The centrifuge ( 10 ; 150 ) according to claim 1 , further comprising a partition wall ( 30 ; 166 ) in the housing ( 12 ; 152 ), wherein the first section ( 40 ; 176 ) of the refrigerant line ( 42 ; 178 ) is arranged on one side of the partition wall ( 30 ; 166 ) and the second section ( 52 ; 192 ) of the refrigerant line ( 42 ; 178 ) is arranged on an opposite side of the partition wall ( 30 ; 166 ), and wherein the second section ( 52 ; 192 ) of the refrigerant line ( 42 ; 178 ) includes at least one connection point ( 98 ).
  3. 3 . The centrifuge ( 10 ; 150 ) according to claim 2 , wherein the partition wall ( 30 ; 166 ) separates the housing ( 12 ; 152 ) into two chambers ( 32 , 34 ; 168 ; 170 ) including a first chamber ( 32 ; 168 ) and a second chamber ( 34 ; 170 ), wherein the first chamber ( 32 ; 168 ) surrounds the centrifuge container ( 36 ; 172 ) at least in some areas and the compressor ( 46 ; 184 ) is arranged in the second chamber ( 34 ; 170 ), and/or wherein the first section ( 40 ; 176 ) of the refrigerant line ( 42 ; 178 ) is arranged in the first chamber ( 32 ; 168 ) and the second section ( 52 ; 192 ) of the refrigerant line ( 42 ; 178 ) is arranged in the second chamber ( 34 ; 170 ).
  4. 4 . The centrifuge ( 10 ; 150 ) according to claim 3 , wherein the partition wall ( 30 ; 166 ) provides a fluid-tight separation between the two chambers ( 32 , 34 ; 168 , 170 ).
  5. 5 . The centrifuge ( 10 ; 150 ) according to claim 3 , wherein the second chamber ( 34 ; 170 ) does not contain any elements ( 46 , 50 ; 184 , 188 , 190 ) which can generate an ignition impulse for igniting the flammable refrigerant.
  6. 6 . The centrifuge ( 10 ; 150 ) according to claim 3 , wherein the first chamber ( 32 ; 168 ) is closed except for ventilation openings ( 60 ).
  7. 7 . The centrifuge ( 10 ; 150 ) according to claim 6 , wherein the first chamber ( 32 ; 168 ) is fluid-tight, and/or wherein the first chamber ( 32 ; 168 ) can be sealed shut in a fluid-tight manner by the cover ( 24 ).
  8. 8 . The centrifuge ( 10 ; 150 ) according to claim 3 , wherein in the area of the first section ( 40 ; 176 ) of the refrigerant line ( 42 ; 178 ) and/or in the area of the first chamber ( 32 ; 168 ), the housing ( 12 ; 152 ) does not have any perforations for air exchange in the housing bottom ( 20 ; 160 ).
  9. 9 . The centrifuge ( 10 ; 150 ) according to claim 2 , further comprising a fluid-tight seal between the partition wall ( 30 ; 166 ) and the housing ( 12 ; 152 ), wherein the fluid-tight seal surrounds the partition wall ( 30 ; 166 ) completely, and wherein the fluid-tight seal is a lip seal ( 202 , 204 ) or a sealing strip ( 206 ).
  10. 10 . The centrifuge ( 10 ; 150 ) according to claim 2 , further comprising a feed-through ( 80 , 82 ) through the partition wall ( 30 ; 166 ) with a fluid-tight seal, wherein the fluid-tight seal is a rubber grommet ( 88 ), and/or a sealing contour ( 84 ), and wherein the feed-through ( 80 , 82 ) is a feed-through for cables and/or the refrigerant line ( 42 ; 178 ).
  11. 11 . The centrifuge ( 10 ; 150 ) according to claim 2 , further comprising a safety vessel ( 92 ) that surrounds the centrifuge container ( 36 ) at least partially, wherein at least a first area ( 94 ) of the refrigerant line ( 42 ) extends inside the safety vessel ( 92 ), wherein a second area ( 96 ) of the refrigerant line ( 42 ) extends between safety vessel ( 92 ) and the partition wall ( 30 ), wherein the first area ( 94 ) of the refrigerant line ( 42 ) and/or the second area ( 96 ) of the refrigerant line ( 42 ) is designed without connection points.
  12. 12 . The centrifuge ( 10 ; 150 ) according to claim 11 , wherein a feed-through through the safety vessel includes a fluid-tight seal, wherein the fluid-tight seal is a rubber grommet and/or a sealing contour, and wherein the feed-through is configured for cables and/or the refrigerant line ( 42 ; 178 ).
  13. 13 . The centrifuge ( 10 ; 150 ) according to claim 2 , wherein the partition wall ( 30 ; 166 ) comprises plastic and/or metal, and/or wherein the partition wall ( 166 ) comprises a thermal insulation foam integrally connected to a thermal insulation material of the centrifuge container ( 172 ), and/or wherein the partition wall ( 30 ; 166 ) comprises a fluid-tight foil, plastic plate, or metal plate.
  14. 14 . The centrifuge ( 150 ) according to claim 2 , wherein the partition wall ( 166 ) has a drainage duct which leads away from a connection point of the refrigerant line ( 178 ) arranged in the partition wall ( 166 ) to the second section ( 192 ) of the refrigerant line ( 178 ), wherein the drainage duct is a line, and wherein the connection point arranged in the partition wall ( 166 ) is surrounded by a fluid-tight jacket to which the drainage duct is connected.
  15. 15 . The centrifuge ( 10 ; 150 ) according to claim 1 , further comprising perforations ( 60 ) for air exchange in the housing wall ( 18 , 18 a ) in the area of the first section ( 40 ; 176 ) of the refrigerant line ( 42 ; 178 ), wherein the perforations ( 60 ) have a distance from a base area ( 28 ; 164 ) of the centrifuge ( 10 ; 150 ) of at least 2 cm, and/or further comprising at least one perforation ( 60 ; 78 ) for air exchange in the housing wall ( 18 , 18 a , 19 ) both in the area of the first section ( 40 ; 176 ) of the refrigerant line ( 42 ; 178 ) and in the area of the second section ( 52 ; 192 ) of the refrigerant line ( 42 ; 178 ), wherein the at least one perforation ( 78 ) in the area of the second section ( 52 ; 192 ) are arranged closer to the base area ( 28 ; 164 ) of the centrifuge ( 10 ; 150 ), wherein the at least one perforation ( 60 ) in the area of the second section ( 52 ; 192 ) are preferably arranged at least 1 cm closer to the base area ( 28 ; 164 ) of the centrifuge ( 10 ; 150 ).
  16. 16 . The centrifuge ( 10 ; 150 ) according to claim 1 , wherein the housing ( 12 ; 152 ) includes feet ( 26 ; 162 ) for spacing the housing bottom ( 20 ; 160 ) apart from a base area ( 28 ; 164 ) of the centrifuge ( 10 ; 150 ), wherein the feet ( 26 ; 162 ) have a height of at least 1 cm, and wherein the centrifuge is a laboratory centrifuge ( 10 ; 150 ).

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of German Patent Application DE 10 2024 132 552.6, filed on Nov. 7, 2024, the content of which is incorporated in its entirety. TECHNICAL FIELD The present disclosure relates to a centrifuge comprising a flammable temperature-control medium. BACKGROUND Centrifuges, in particular laboratory centrifuges, are used to separate the component parts of samples centrifuged therein by using mass inertia. In the process, increasingly high rotation speeds are used to achieve high demixing rates. Laboratory centrifuges are centrifuges with centrifuge rotors that operate at preferentially at least 3000, preferably at least 10,000, in particular at least 15,000 revolutions per minute, and are usually placed on tables. In order to be able to place them on a work table, they have in particular a form factor of less than 1 m×1 m×1 m, meaning that their installation space is restricted. In this case, the device depth is preferably restricted to 70 cm maximum. Such centrifuges are employed in the fields of medicine, pharmacy, biology, chemistry and the like. The samples to be centrifuged are stored in sample containers and these sample containers are driven in rotation by means of a centrifuge rotor. Various types of centrifuge rotors, for example swing-out rotors and fixed-angle rotors, are used depending on their intended use. A common feature of most of these centrifuge rotors is that they have a rotor housing with a lower rotor part, in which there may be arranged one or multiple receptacles for sample containers or sample carriers, in which in turn sample containers can be arranged. In addition, the lower rotor part usually has a hub that can be coupled to a drive shaft driven by a centrifuge motor. In this case, the sample containers can contain the samples directly or the sample containers have their own sample containers inserted therein that contain the sample, meaning that a plurality of samples can be centrifuged in one sample container at the same time. It is usually provided that the samples are centrifuged at certain temperatures. For example, samples containing proteins and similar organic substances are not allowed to be overheated, meaning that the upper limit for the temperature-control of such samples is in the region of 40° C. as standard. On the other hand, certain samples are cooled as standard in the region of +4° C. (the anomaly of the water begins at 3.98° C.). In addition to such predetermined maximum temperatures of, for example, approx. +40° C. and standard testing temperatures of, for example, 4° C., further standard testing temperatures are also provided, such as, for example, at 11° C., in order to check at this temperature whether the refrigeration system of the centrifuge is running in a controlled manner below room temperature. On the other hand, it is necessary for occupational safety reasons to prevent elements having a temperature of greater than or equal to 60° C. from touching. Reference values are specified in DIN EN 61010-1:2011-07, Table 19. In principle, active and passive systems can be used for temperature control. Passive systems are based on exhaust air-assisted cooling or ventilation. This air is led directly past the centrifuge rotor and thus also past the sample containers housed therein, thereby effecting temperature control. The air is sucked through openings into the centrifuge vessel and the heated air is discharged again at another point of the centrifuge vessel through further openings, wherein the suction and discharge is effected independently due to the rotation of the centrifuge rotor. Active cooling systems have a refrigerant circuit that controls the temperature of the centrifuge container (centrifuge vessel), thereby indirectly cooling the centrifuge rotor and the sample containers housed therein. For this, the refrigerant circuit has a line section which is adjacent to the centrifuge container and is wound around the latter in one or multiple turns. Many different media find use as refrigerant or temperature-control media. Since in principle not only cooling, i.e. heat reduction, but also a heat increase can be desired in a targeted manner during centrifugation, the present application refers to temperature control and temperature-control media. In addition to the temperature control media usually used for centrifuges, such as chlorodifluoromethane, tetrafluoroethane, pentafluoroethane or difluoromethane and carbon dioxide and many others, there are also flammable refrigerants, such as butane (R600a) or propane (R290), or also a wide variety of synthetic mixtures. Although these flammable temperature-control media have very good heat transfer properties, they have to date not usually used for safety reasons, since the temperature-control media can escape and ignite in the event of a crash of the centrifuge rotor. In such a crash, fragments of the centrifuge rotor can act at high velocity a