Centrifuge with airflow system

Abstract

A centrifuge (1) having a rotor chamber (2) containing a rotor (3) rotationally driven by a shaft (4) defining an axis of rotation (R), and wherein the centrifuge (1) comprises an air inlet (21) and an air outlet (22) wherein the rotor (3) is arranged axially between the air inlet (21) and the air outlet (22), wherein a rotationally fixed gas cutting disc (10) is arranged within the rotor chamber (2) between the air outlet (22) and the rotor (3), and the gas cutting disc (10) defines an air flow channel (13) from a radially outer periphery (12) of the gas cutting disc (10) radially inward towards a central portion (15) of the gas cutting disc (10).

Description

Technical Field

[0001] The invention belongs to the technical field of laboratory centrifuges, in particular to the field of cooling arrangements and air guides for ventilated centrifuges. Background Art

[0002] The application of laboratory centrifuges is to separate higher density and lower density substances by the sedimentation principle. Therefore, laboratory centrifuges include a rotor with a receiver for a sample container. In most cases, the sample container is arranged relative to the circumference of the rotor. The rotor of the centrifuge is driven rotationally around the central axis, thereby applying centrifugal acceleration to the sample container and the sample therein. In this way, forces several orders of magnitude higher than the forces that can be achieved under gravitational acceleration can be applied to the sample. The radial acceleration during the operation of the centrifuge causes the denser particles to settle outward in the radial direction, while the low-density substances are forced inward. The rotor rotates at a high rotational speed. Typical speeds are above 10,000 rpm. A cylindrical rotor with a diameter of 0.2 m has a circumferential speed of about 180 m / s at a rotational speed of 17,000 rpm.

[0003] A ventilated centrifuge has an air-filled chamber in which the rotor rotates. The chamber is usually covered with a cover at the top. The air contained in the chamber is accelerated by the rotation of the rotor, and the friction between the rotor and the contained air causes heating of the rotor, the air, and the sample carried by the rotor.

[0004] Such elevated temperatures may lead to side reactions in the sample which may have a negative effect on further diagnostic examinations. It is generally desirable to heat the sample to less than 15K above ambient temperature so that at room temperature of 22°C the sample temperature does not exceed 37°C.

[0005] To avoid this heating, ventilated centrifuges use ambient air to cool the rotor. The air is entrained by the rotational motion of the rotor and accelerated outwards in the radial direction towards the substantially vertical walls of the rotor chamber. As a result, a pressure gradient is created in the radial direction, i.e. from the high pressure at the axis of rotation of the rotor towards lower pressures at the circumference of the rotor and higher pressures. The air is sucked in from the outside through air ducts around the center of rotation and leaves the unit through air outlets at a further point. The flowing air is a source of acoustic interference that needs to be reduced. The build volume of the centrifuge in the radial direction is mostly limited because preferably the user requires a compact instrument, so if the entrained and radially accelerated air leaves the rotor chamber through openings in the vertical walls, there is very limited available space in the radial direction for noise insulation measures.

[0006] WO 2020 212 045A1 shows an air inlet at the bottom of the centrifugal chamber and an outlet at the top. Air is sucked into the chamber via a rotor or via a ventilator. After being guided from the bottom to the top and passing through the chamber, the air is subsequently discharged and / or guided back to the motor in the bottom of the centrifuge. The air is guided via a multi-part air guide assembly formed by a foam material (PP or PU). The air inlet is arranged near the axis of rotation, and the air is guided by the air guide assembly in the direction of rotation of the rotor.

[0007] This arrangement requires a multi-part air guide assembly with complex internal ductwork. The chamber is separated from the housing and insulation is required to prevent the inlet airflow from heating up due to the centrifuge motor. Separation of the air inlet and outlet is required. This results in increased space requirements because the outlet airflow requires a passage between the outer contour of the chamber and the housing.

[0008] US 6,068,586 A relates to the cooling of a laboratory centrifuge, wherein during operation, the centrifuge is cooled by cooling air, which is sucked in through an air inlet opening in the lower side of the housing and enters upward into the rotor chamber by the fan action generated by the rotation of the rotor. The air is guided out of the rotor chamber through an air outlet in a flow direction tangential to the rotor periphery in a manner that ensures low turbulence. In particular, a slit-shaped air outlet is provided between the housing cover and the top edge of the rotor chamber. The air is introduced via holes in the rotor chamber and the air is discharged via a slit-shaped opening between the lower cover cover and the top side of the housing. The introduced air is heated by the motor. Therefore, a reduced cooling performance is expected. Although a turbulence-inducing cover can be foreseen, an increase in noise level is estimated due to the direct coupling of the air outlet to the rotor chamber.

[0009] DE 103 55 179A1 shows a kind of air-cooled centrifuge, this centrifuge has for air supply to the inlet section in centrifugal container, be arranged in the channel area for air discharged from centrifugal container outside and for air discharged from centrifugal container pipeline area, wherein at least diffuser is arranged in the upstream of channel area.DE 103 55 179A1 shows diffuser element at the upper edge of centrifugal container in particular.Diffuser element spans about one-fourth of the circumference and guides air to the air outlet of the lower part of centrifugal chamber.Air is guided into centrifuge via the opening in the lower cover cover, and air is discharged from centrifuge via the gap between the top edge of chamber and the table plate of shell.Air guiding device is included in the diffuser at the beginning of air outlet channel.This is a kind of expensive structure, and because additional parts and because the passage between the outer contour of chamber and shell is needed for outlet airflow, radial space is needed.

[0010] US 5,490,830 A shows a centrifuge, which is cooled via a fan, which draws air through a centrifuge housing, and the centrifuge housing has an internal configuration for providing air flow on and around the outside of a sealed rotor chamber. The fan draws air into the lower part of the housing through an inlet, and the lower part is separated from the upper part of the housing via a guide plate, which cooperates with the wall of the centrifuge housing except for the gap at the front wall of the housing. The drive motor is located in the guide plate so that cooling air is sucked into the upper part of the centrifuge housing and around the motor in the lower part by the motor. The airflow generated by the fan is directed to the rotor chamber and around the rotor chamber. The air inlet and outlet are arranged in the rear sheet of the centrifuge. Due to the need for an additional fan to generate airflow, this arrangement is expensive. In addition, since air needs space to flow around the rotor chamber, there is a space requirement. Summary of the invention

[0011] The problem to be solved is to foresee a compact, efficient and quiet air guide arrangement for cooling samples in a ventilated centrifuge and / or for downstream cooling of a centrifuge drive with a reduced noise level.

[0012] The invention described here is associated with the definition of an air flow channel in a rotor chamber of a ventilated centrifuge according to claim 1 .

[0013] The present invention relates to a centrifuge, preferably a ventilated centrifuge having a rotor chamber containing a rotor driven in rotation by a shaft defining an axis of rotation, and wherein the centrifuge comprises an air inlet and an air outlet, wherein the rotor is axially arranged between the air inlet and the air outlet, whereby the present invention foresees a rotationally fixed gas cutting disk being arranged in the rotor chamber between the air outlet and the rotor, and the gas cutting disk defining an air flow channel radially inwards from a radially outer periphery of the gas cutting disk towards a central portion of the gas cutting disk.

[0014] By means of the air flow channel, air is guided through the rotor chamber from the air inlet to the air outlet. The air flow channel is a limited path in which air is guided. The gas cutting disc is used as a separation of the air flow in the air flow channel from the rotating rotor. The rotation of the rotor forces the air to flow radially outward to the radial wall of the rotor chamber. The gas cutting disc produces flow separation from the radially outward acceleration, which is mainly caused by the friction of the entrained air and the rotor, and therefore allows the air to flow radially inward toward the center of the gas cutting disc, and then flow to the air outlet of the centrifuge. In this way, the air throughput is increased, and therefore better cooling performance is allowed. Another advantage is that the noise emission of the centrifuge is reduced by utilizing this gas cutting disc.

[0015] According to another aspect of the invention, the air cutting discs may be arranged concentrically with the axis of rotation. This arrangement contributes to the overall symmetry of the system and has proven to be beneficial for the flow in the air guide channels defined by the air guide discs. By using a concentric arrangement, the obstruction of the air accelerated radially outwards by the rotor in the rotor chamber is further reduced, which further contributes to the above-mentioned benefits of improved cooling performance and reduced noise.

[0016] In another aspect of the present invention, it is foreseeable that the gas cutting disc can have one or more air deflectors for deflecting air. The air in the rotor chamber is not only picked up by the friction at the interface of the rotating rotor of the centrifuge, and is therefore pushed radially outward, but the air picked up by the rotor will also have a motion component in the direction of rotation of the rotor. The air deflector can pick up the air with this composition, and help deflect it to the radially inward direction in the air flow channel. Preferably, the gas cutting disc can extend radially from the axis of rotation, and the one or more air deflectors can be axial protrusions relative to the axis of rotation, and these air deflectors can protrude from the gas cutting disc towards the air outlet. Optionally, the one or more air deflectors can be formed integrally with the gas cutting disc.

[0017] According to another aspect of the invention, the one or more air deflectors may have a chamfer or radius between the gas cutting disc and their axial protrusion. Such a radius or chamfer serves as a smooth transition, especially if the gas cutting disc is a disc protruding mainly in the radial direction and the air deflector protrudes substantially vertically in the axial direction. Air turbulence is reduced, which helps to improve air flow and reduce associated noise.

[0018] In another aspect of the present invention, it is foreseeable that the one or more air deflectors may extend from the central portion of the gas cutting disk to the outer periphery of the gas cutting disk in an arcuate manner. Preferably, but not exclusively, the arc is specifically implemented to open against the direction of rotation of the rotor. In another aspect of the present invention, it is foreseeable that the one or more air deflectors may be concave against the direction of rotation of the rotor. This does advantageously support the entrainment of air accelerated by the rotor in the air flow channel. According to another aspect of the present invention and producing the same benefits, one or more air deflectors may be arranged in a spiral. Air entrainment may be further improved by another aspect of the present invention, according to which the air deflectors may be tangent to the outer periphery of the gas cutting disk, and wherein the air deflectors may further draw an arc toward the central portion of the gas cutting disk, preferably opening against the direction of rotation of the rotor.

[0019] In another aspect of the invention, it is foreseeable that the gas cutting disc may have a central portion that is offset from the outer portion in the axial direction. Such an axially offset or curved embodiment of the gas cutting disc may be used to increase the cross-section of the air flow passage defined by the gas cutting disc and thus facilitate a reduction in air throughput and noise emission, since the velocity of the air flowing through the air flow passage is reduced relative to the cross-sectional area of ​​the air flow passage.

[0020] According to another aspect of the invention, the one or more air deflectors may have a plurality of engagement features for torque-proof connection of the gas cutting disc to the rotor chamber. In this way, the gas cutting disc is held in a rotationally locked position relative to the rotor, wherein the above-mentioned benefits are not reduced to the gas cutting disc being partially entrained in the rotational movement of the centrifuge rotor.

[0021] In another aspect of the present invention, it is foreseeable that the gas cutting disc can have a through opening arranged at the center portion of the gas cutting disc, and the through opening can be configured to feed through the shaft of the centrifuge. This arrangement significantly improves the construction of the centrifuge with a gas cutting disc, which defines an air flow channel in the rotor chamber, in particular, if according to another aspect of the present invention, the rotor chamber can be opened upward, and the top of the chamber can be covered by a cover, and the air inlet can be arranged in the cover. In particular, if it is foreseeable that the air outlet can be arranged at the bottom part of the chamber. According to another aspect of the present invention, the gas cutting disc can be arranged between the bottom part of the rotor chamber and the rotor, wherein the air inlet can be arranged in the cover of the centrifuge, and the air outlet is arranged in the bottom part of the rotor chamber. Basically, the gas cutting disc can be arranged between the air outlet and the rotor of the centrifuge in this way, and the air outlet is arranged in the bottom of the bowl-shaped rotor chamber, wherein the rotor is driven by an axis extending through the bottom of the rotor chamber and the gas cutting disc. The bowl-shaped rotor chamber is closed by a cover at its upward opening, wherein the cover has an air inlet. Therefore, the air is accelerated by the rotor toward the radial wall of the rotor chamber and further guided through the air flow channel defined by the gas cutting disc and the bottom of the rotor chamber. New air is forced into the rotor chamber through the air inlet and the pressure difference generated by the radial acceleration of the air entrained in the rotor chamber. The gas cutting disc is used to separate the air flow forced radially outward from the air flow in the air flow channel, which is radially inward toward the air outlet at the bottom of the rotor chamber, by the rotation of the rotor and the friction between the rotor and the air.

[0022] According to another aspect of the invention, the air inlet and / or air outlet may be arranged concentrically with the axis of rotation. This further contributes to efficient air exchange, since the minimum pressure is approximately at the center of rotation, so that air is efficiently sucked in through the air inlet and the rotationally agitated air is also efficiently directed radially inwards to its center of rotation without any significant loss of air velocity or generation of unnecessary turbulence.

[0023] Therefore, while maintaining the above advantages, it can be foreseen that in another aspect of the present invention, the air inlet, the air outlet, the rotor, the rotor chamber and the gas cutting disc can form an air flow path from the air inlet through the gap between the outer periphery of the rotor and the axial wall of the rotor chamber, across the air flow channel defined by the gas cutting disc to the air outlet. According to another aspect of the present invention, the gas cutting disc can separate the air directed radially inward between the gas cutting disc and the bottom portion of the chamber from the rotor, and specifically from the face of the rotor facing the bottom portion of the chamber. Therefore, the gas cutting disc serves to separate the air flow in the air flow channel from the rotating rotor, and separates the radially inward air flow in the air flow channel flowing to the air outlet from any radially outward air flow caused by the air picked up by the rotating rotor during the operation of the centrifuge.

[0024] In another aspect of the invention, it is foreseen that the outer periphery of the gas cutting disk may correspond to the lower outer rotating periphery of the rotor, which improves air intake into the air flow passage defined by the gas cutting disk.

[0025] According to another aspect of the invention, the gas cutting disc can guide the air flow axially downward toward the air outlet, and in another aspect of the invention, it is foreseeable that the one or more air guide plates can extend radially outward beyond the radial outer periphery of the air outlet, and / or the one or more air guide plates can extend radially inward beyond the radial outer periphery of the air outlet. In this way, the air guidance toward the air outlet is further improved.

[0026] In another aspect of the invention, it is foreseeable that the air inlet may have a smaller diameter than the air outlet. Such dimensions further improve the efficiency of the air exchange, since the air outlet is kept from constituting a bottleneck. In this way, any excess pressure buildup between the periphery of the rotor and the radial wall of the rotor chamber is avoided.

[0027] According to another aspect of the invention, the air outlet can be located on the periphery relative to the rotor chamber, wherein the periphery can be less than the rotational periphery of the rotor. In another aspect of the invention, it is foreseeable that the air outlet can be an annular opening, which can be limited radially outward by the rotor chamber and radially inwardly by the shaft housing of the centrifuge. According to another aspect of the invention, the gas cutting disc can protrude radially between the bottom portion of the chamber and the rotor. In another aspect of the invention, it is foreseeable that the gas cutting disc can be in axial contact with the shaft housing of the centrifuge. By using this design, a structural advantage is created in terms of the through-channel of the rotor shaft and any bearing against the rotor housing, while maintaining a sufficiently large air outlet so as to effectively discharge air from the rotor chamber.

[0028] In another aspect of the invention, it is foreseeable that air can be directed through the air outlet of the rotor chamber and can be further directed around the motor and can leave the centrifuge through the outlet hole. In this way, air inadvertently sucked into the rotor chamber of the ventilated centrifuge can also be used for cooling purposes of the motor. By directing the air through the air guide and then to the air outlet leading to the motor, the motor is kept from preheating the air sucked into the air inlet.

[0029] According to another aspect of the invention, the gas cutting disc can be arranged between the rotor and the cover, wherein the air inlet can be arranged in the bottom part of the rotor chamber, and the air outlet can be arranged in the cover of the centrifuge. This design has advantages in certain applications, wherein for configuration or analytical reasons, it is not possible to introduce the ventilation air of the ventilated centrifuge from the side of the cover.

[0030] It is obvious to those skilled in the art that the gas cutting disc described in the above various embodiments can also constitute an independent device for improving the airflow in an existing ventilated centrifuge. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will now be described in conjunction with the following non-limiting drawings. Further advantages of the present disclosure will be apparent by reference to the detailed description when considered in conjunction with the accompanying drawings, in which:

[0032] - Figure 1 shows a schematic cross-sectional view through the rotor chamber of a ventilated centrifuge;

[0033] - Figure 2 A perspective view of a gas cutting disc is shown;

[0034] - Figure 3 Shows relative to passing through the Figure 1 a schematic cross-sectional air flow path of a rotor chamber of a ventilated centrifuge; and

[0035] - Figure 4An air flow path through an air flow passage at least partially defined by the gas cutting disk is shown in a bottom view of the gas cutting disk. DETAILED DESCRIPTION

[0036] Figure 1 A cross section of a centrifuge 1 having a rotor chamber 2 is shown, wherein the rotor chamber 2 contains a rotor 3 which is rotationally driven by a shaft 4 defining an axis of rotation R. The centrifuge 1 comprises an air inlet 21 to the rotor chamber 2 and an air outlet 22 from the rotor chamber 2 .

[0037] The rotor 3 is arranged axially between the air inlet 21 and the air outlet 22, and a rotationally fixed gas cutting disk 10 is arranged in the rotor chamber 2 between the air outlet 22 and the rotor 3. The gas cutting disk 10 is arranged concentrically with the rotation axis R, and the outer periphery 12 of the gas cutting disk 10 corresponds to the lower outer rotational periphery 32 of the rotor.

[0038] The rotor chamber 2 is open upwards, the chamber top 23 is covered by a cover 25, and the air inlet 21 is arranged in the cover 25. The rotor chamber 2 is bowl-shaped, and the air outlet 22 is arranged in the bottom part 24 of the chamber 2. The air inlet 21 and the air outlet 22 are arranged concentrically with the rotation axis R and with the rotor 3 and the gas cutting disc 10.

[0039] The gas cutting disc 10 is in axial contact with the shaft housing 42 of the centrifuge and projects radially between the bottom part 24 of the chamber 2 and the rotor 3 .

[0040] Now refer to Figure 2 and Figure 4 The gas cutting disk 10 defines an air flow channel 13 from a radially outer periphery 12 of the gas cutting disk 10 radially inwardly toward a central portion 15 of the gas cutting disk 10. The air flow channel 13 is also formed by several air deflectors 11a-d, which are embodied as protrusions relative to the rotation axis R, axially protruding from the radially extending gas cutting disk 10. The air deflectors 11a-d are integrally formed with the gas cutting disk 10 and have a chamfer or radius 14 between the gas cutting disk 10 and their axial protrusions.

[0041] The air deflectors 11a-d extend in an arcuate manner from the center 15 of the gas cutting disk 10 to the outer periphery 12 of the gas cutting disk, more specifically and as shown from Figure 2 and Figure 4As can be seen in the figure, the air deflectors 11a-d are tangential to the outer periphery 12 of the gas cutting disk 10 and are arranged in a spiral and open against the direction of rotation D of the rotor 3. The air deflectors 11a-d have a plurality of engagement features 17, which are embodied here as sockets for bolts for a torque-proof connection of the gas cutting disk 10 to the rotor chamber 2. The center part 15 of the gas cutting disk 10 is offset from the outer part 16 of the gas cutting disk 10 in the axial direction. The center 15 of the gas cutting disk 10 has a through opening 18, such as Figure 1 and Figure 3 As shown, the through-opening is configured to feed through the shaft 4 of the centrifuge 11 .

[0042] As from Figure 3 and Figure 4 As best seen in the figure, the air inlet 21, the air outlet 22, the rotor 3, the rotor chamber 2 and the gas cutting disk 10 form an air flow path 6 from the air inlet 22 through the gap 35 between the outer periphery 32 of the rotor 3 and the axially extending wall 26 of the rotor chamber 2 and further across the air flow channel 13 to the air outlet 22.

[0043] The gas cutting disk 10 separates the air directed radially inwards between the gas cutting disk 10 and the bottom part 24 of the rotor chamber 2 from the rotor 3 , in particular from the face 36 of the rotor 3 facing the bottom part 24 of the chamber 2 .

[0044] from Figure 3 It can be further seen in the figure that the gas cutting disc 10 directs the air flow axially downwardly towards the air outlet 22, and the air guide plates 11a-d extend radially outwardly and radially inwardly beyond the air outlet 22. Figure 3 It can be further seen that the air inlet 21 has a smaller diameter than the air outlet 22, and the air inlet 21 also has a resulting cross-sectional area that is smaller than the cross-sectional area of ​​the air outlet 22, although the air outlet 22 is specifically implemented as an annular opening, which is radially limited outwardly by the rotor chamber 2 and radially limited inwardly by the shaft housing 42 of the centrifuge 1.

[0045] As from Figure 3 As is evident in the drawing, the air is guided through the air outlet 22 of the rotor chamber 2 and can thus be guided further around the motor of the centrifuge and can leave the centrifuge 1 through the outlet opening, which is not shown in the drawing.

[0046] It should be understood that the present disclosure is not limited to the above-described embodiments and that modifications and variations to the above-described embodiments will be apparent to those skilled in the art.

[0047] For example, it is foreseeable that the gas cutting disc is arranged between the rotor and the cover, wherein the air inlet is arranged at the bottom part of the rotor chamber, and the air outlet is arranged in the cover of the centrifuge. Then, the air flow path will pass through the gap between the axial walls of the rotor chamber from the bottom of the rotor chamber, and then be guided by the gas cutting disc in the air guide channel between the gas cutting disc and the cover. This embodiment may have advantages in certain applications, wherein for structural or analytical reasons, it is impossible to introduce the ventilation air of the ventilated centrifuge from the side of the cover.

[0048] It will be apparent to those skilled in the art that features of the above-described embodiments may be combined in any suitable combination with features of other embodiments described above, and that particular combinations of features described in the above-described embodiments are not to be construed as limiting.

[0049] Reference numerals list

[0050] 1 Centrifuge

[0051] 2 Rotor chamber

[0052] 3 Rotor

[0053] 4 Axis

[0054] 10 Gas cutting disc

[0055] 11a-d Air deflector

[0056] 12 (Outer perimeter of gas cutting disc)

[0057] 13 Air flow channel

[0058] 14 Chamfer, radius

[0059] 15 Center part (of gas cutting disc)

[0060] 16 External part (of gas cutting disc)

[0061] 17 Engagement feature

[0062] 18 Through opening

[0063] 21 Air Inlet

[0064] 22 Air outlet

[0065] Room 23 Top

[0066] 24 Bottom section

[0067] 25 Cover

[0068] 26 Axial wall

[0069] 32 (rotor) outer rotation circumference

[0070] 35 Gap

[0071] 36 (Rotor) surface

[0072] 42 Axis housing

[0073] R Rotation axis

[0074] D Rotation direction

Claims

1. A centrifuge (1) having a rotor chamber (2) containing a rotor (3) driven in rotation by a shaft (4) defining an axis of rotation (R), and wherein: The centrifuge (1) comprises an air inlet (21) and an air outlet (22), wherein: The rotor (3) is arranged axially between the air inlet (21) and the air outlet (22), and is characterized in that: A rotationally fixed gas cutting disc (10) is arranged in the rotor chamber (2) between the air outlet (22) and the rotor (3); and The gas cutting disk (10) defines an air flow passage (13) extending radially inward from a radially outer periphery (12) of the gas cutting disk (10) toward a central portion (15) of the gas cutting disk (10).

2. The centrifuge (1) according to claim 1, characterized in that The gas cutting disc (10) is arranged concentrically with the rotation axis (R), and the gas cutting disc (1) has one or more air guide plates (11a-d) for deflecting air.

3. The centrifuge (1) according to claim 2, characterized in that The one or more air guide plates (11a-d) are arranged in a spiral shape, and the one or more air guide plates (11a-d) are tangent to the outer periphery of the gas cutting disc (10).

4. The centrifuge (1) according to any one of claims 2 or 3, characterized in that The one or more air deflectors (11a-d) have an engagement feature (17) for a torque-proof connection of the gas cutting disc (10) to the rotor chamber (2).

5. A centrifuge (1) according to any one of the preceding claims, characterised in that The gas cutting disc (10) has a through opening (18) arranged at the central portion (15) of the gas cutting disc (10), and the through opening (18) is configured to feed through the shaft (4) of the centrifuge (1).

6. A centrifuge (1) according to any one of the preceding claims, characterized in that The air inlet (21) and / or the air outlet (22) are arranged concentrically with the rotation axis (R).

7. A centrifuge (1) according to any one of the preceding claims, characterised in that The air inlet (21), the air outlet (22), the rotor (3), the rotor chamber (2) and the gas cutting disk (10) form an air flow path, which flows from the air inlet (21) arranged in the cover (25) of the centrifuge (1) through the gap (35) between the outer periphery of the rotor (32) and the axial wall (26) of the rotor chamber (2) across the air flow channel (13) defined by the gas cutting disk (10) to the air outlet (22) arranged in the bottom part (24) of the rotor chamber (2).

8. A centrifuge (1) according to any one of the preceding claims, characterised in that The gas cutting disc (10) separates the air directed radially inwards between the gas cutting disc (10) and the bottom portion (24) of the chamber (2) from the rotor (3).

9. A centrifuge (1) according to any one of the preceding claims, characterised in that The outer periphery (12) of the gas cutting disc (10) corresponds to the lower outer rotating periphery (32) of the rotor (3).

10. The centrifuge (1) according to any one of the preceding claims, characterized in that The air outlet (22) is located on a periphery relative to the rotor chamber (2), wherein the periphery is smaller than the rotational periphery (32) of the rotor (3).

11. The centrifuge (1) according to any one of the preceding claims, characterized in that The air outlet (22) is an annular opening which is delimited radially outwardly by the rotor chamber (2) and radially inwardly by a shaft housing (42) of the centrifuge (1).

12. Centrifuge (1) according to any one of the preceding claims, characterized in that The gas cutting disc (10) protrudes radially between the bottom part (24) of the rotor chamber (2) and the rotor (3).

13. The centrifuge (1) according to any one of the preceding claims, characterized in that The gas cutting disc (10) is in axial contact with the shaft housing (42) of the centrifuge (1).

14. Centrifuge (1) according to any one of the preceding claims, characterized in that The air is directed through the air outlet (22) of the rotor chamber (2), the air is also directed around the motor of the centrifuge (1), and leaves the centrifuge (1) through an outlet opening.

15. The centrifuge (1) according to any one of claims 1 to 7 and 9 to 13, characterized in that The gas cutting disc (10) is arranged between the rotor (3) and the cover (25), wherein the air inlet (21) is arranged in the bottom part (24) of the rotor chamber (2) and the air outlet (22) is arranged in the cover (25) of the centrifuge (1).

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