Centrifuge with an airflow system

Abstract

Centrifuge (1) with a rotor chamber (2) containing a rotor (3) which is driven to rotate 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 axially arranged between the air inlet (21) and the air outlet (22), wherein a rotationally fixed air separator (10) is arranged within the rotor chamber (2) between the air outlet (22) and the rotor (3), and the air separator (10) defines an airflow channel (13) from a radially outer circumference (12) of the air separator (10) radially inwards towards a central section (15) of the air separator (10).

Description

[0001] The invention lies in the technical field of laboratory centrifuges and in particular in the field of cooling arrangements and air ducts for ventilated centrifuges.

[0002] One application for laboratory centrifuges is the separation of substances of higher and lower density using the principle of sedimentation. Laboratory centrifuges therefore include rotors that have holders for sample containers. The sample containers are usually arranged relative to a circumference of the rotor. The centrifuge rotor is driven to rotate around a central axis, exerting centrifugal acceleration on the sample containers and the samples within. In this way, it is possible to exert forces on the samples that are several orders of magnitude higher than those achievable under gravity. The radial acceleration during centrifuge operation causes denser particles to settle outwards in a radial direction, while less dense substances are pushed inwards. The rotor rotates at a high speed. Typical speeds are over 10,000 rpm.A cylindrical rotor with a diameter of 0.2 m at a speed of 17,000 rpm has a peripheral speed of about 180 m / s.

[0003] Vented centrifuges have an air-filled chamber with a rotating rotor. The chamber is typically covered with a lid. The air contained in the chamber is accelerated by the rotation of the rotor, and the friction between the rotor and the air causes heating of the rotor, the air, and the samples carried by the rotor.

[0004] Such elevated temperatures can lead to side reactions in the sample, which can negatively impact further diagnostic tests. Sample heating of less than 15 K above ambient temperature is typically desirable, so that at room temperature of 22 °C, the sample temperature does not exceed 37 °C.

[0005] To avoid such heating, vented centrifuges use ambient air to cool the rotor. The rotation of the rotor entrains air and accelerates it outward in a radial direction toward a mostly vertical wall of a rotor chamber. This creates a pressure gradient along the radial direction, i.e., from a high pressure at the rotor's rotational axis to a lower pressure at the rotor's periphery and beyond. Air is drawn in from outside through an air duct around the pivot point and exits the unit through an air outlet at a more outward point. The moving air is a source of acoustic noise that must be reduced.The volume of centrifuges in the radial direction is usually limited because users prefer compact instruments, so that a very limited space in the radial direction is available for noise reduction measures when the entrained and radially accelerated air leaves the rotor chamber through openings in the vertical wall.

[0006] WO 2020 / 212045 A1 shows an air inlet in the lower part of the centrifuge chamber and an outlet in the upper part. Air is drawn into the chamber via the rotor or via aeration means. After the air has been guided from the lower part to the upper part and has passed through the chamber, the air is then expelled and / or recirculated to the motor in the lower part of the centrifuge. The air is guided via a multi-part air guide assembly made of foam (PP or PU). The air inlet is located near a rotation axis, and air is guided through the air guide assembly in the direction of rotation of the rotor.

[0007] This arrangement requires a multi-part air duct assembly with a complex internal feedthrough structure. The chamber is separated from the housing and the insulation required to prevent the inlet airflow from being heated by the centrifuge motor. Separation of the air inlet and outlet is necessary. This results in increased space requirements, as the outlet airflow requires a channel 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 the centrifuge is cooled during operation by cooling air drawn upwards into the rotor chamber through air inlets in the underside of the housing and by the fan action generated by the rotation of the rotor. The air is led out of the rotor chamber through an air outlet opening in a flow direction tangential to the circumference of the rotor, thereby ensuring low turbulence. In particular, a slot-shaped air outlet opening is arranged between the casing cover and an upper edge of the rotor chamber. Air is introduced via a hole in the rotor chamber and expelled via the slot-shaped opening between the lower lid cover and the top of the housing. The introduced air is heated by the motor. Thus, a reduced cooling performance is to be expected.Although a turbulence-inducing cover is provided, an increase in noise level is expected due to the direct coupling of the air outlet to the rotor chamber.

[0009] DE 103 55 179 A1 discloses an air-cooled centrifuge with an inlet cross-section for supplying air to the centrifuge vessel, a channel region arranged outside the centrifuge vessel for expelling air from the centrifuge, and a passage region for removing air from the centrifuge vessel, wherein a diffuser is arranged at least upstream of the channel region. DE 103 55 179 A1 specifically discloses a diffuser element at the upper edge of the centrifuge vessel. The diffuser element spans approximately a quarter of the circumference and guides air toward an air outlet at the lower portion of the centrifuge chamber. Air is fed into the centrifuge via openings in the lower lid cover, and air is expelled from the centrifuge via a gap between the upper edge of the chamber and the desktop of the housing. An air-guiding device includes a diffuser at the beginning of the air outlet channel.This is an expensive design and requires radial space due to additional parts and because the exhaust airflow requires a channel between the outer contour of the chamber and the housing.

[0010] US 5,490,830 A shows a centrifuge cooled by a fan that draws air through a centrifuge housing with an internal configuration for providing airflow onto and around the exterior of a sealed rotor chamber. The fan draws air through an inlet into a lower portion of the housing, which is separated from an upper portion of the housing by a baffle that cooperates with the walls of the centrifuge housing, except for a gap at a front wall of the housing. A drive motor is positioned in the baffle so that cooling air is drawn through the motor into the upper portion and around it in the lower portion of the centrifuge housing. The airflow generated by fans is directed to and around the rotor chamber. The air inlet and outlet are located in the rear wall of the centrifuge. This arrangement is expensive due to additional fans required to generate the airflow.There is also a space requirement as the air needs space to flow around the rotor chamber.

[0011] The problem to be solved is to provide a compact, efficient and noiseless airflow arrangement for cooling samples and / or for downstream cooling of a centrifuge drive within a ventilated centrifuge at a reduced noise level.

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

[0013] The invention relates to a centrifuge, preferably a ventilated centrifuge having a rotor chamber containing a rotor which is rotationally driven by a shaft defining a rotation axis, 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, wherein the invention provides that a rotationally fixed air separation disc is arranged within the rotor chamber between the air outlet and the rotor and the air separation disc defines an air flow channel from a radially outer circumference of the air separation disc radially inward towards a central portion of the air separation disc.

[0014] The air flow channel guides air through the rotor chamber from the air inlet to the air outlet. The air flow channel is a defined path along which the air is guided. The air separation disc serves to separate the airflow within the air flow channel and the rotating rotor. The rotation of the rotor forces a radial airflow outward toward a radial wall of the rotor chamber. The air separation disc creates a flow separation from this radial outward acceleration, which is predominantly caused by friction of the entrained air with the rotor, and thus allows the air to flow radially inward toward a central section of the air separation disc and subsequently to the centrifuge's air outlet. In this way, the air throughput is increased and thus enables better cooling performance.An additional advantage is that the noise emission of the centrifuge is reduced with such an air separation disc.

[0015] According to a further aspect of the invention, the air separation disc can be arranged concentrically with the rotational axis. Such an arrangement contributes to the overall symmetry of the system and has proven advantageous for the flow in the air guide channel defined by the air guide disc. By using a concentric arrangement, stagnation of the air accelerated radially outward by the rotor is further reduced in the rotor chamber, which further contributes to the aforementioned advantages of increased cooling performance and noise reduction.

[0016] In a further aspect of the invention, it is provided that the air separation disc can have one or more air baffles for deflecting air. The air within the rotor chamber is not only picked up by its friction at the interface with the rotating rotor of the centrifuge and thus pushed radially outwards, the air picked up by the rotor also has a component of movement in the direction of rotation of the rotor. The air baffles can pick up the air with this component and contribute to deflecting it in a radially inward direction within the air flow channel. Preferably, the air separation disc can extend radially from the axis of rotation and the one or more air baffles can be axial projections with respect to the axis of rotation, and the air baffles can protrude from the air separation disc in the direction of the air outlet.Optionally, the one or more air baffles can be formed integrally with the air separation disc.

[0017] According to a further aspect of the invention, the one or more air baffles may have a bevel or radius between the air separation disc and its axial projection. Such a radius or bevel serves as a smooth transition, particularly when the air separation disc is a disc that protrudes predominantly in the radial direction and the air baffles protrude substantially perpendicularly in the axial direction. Air turbulence is reduced, which contributes to improved airflow and the reduction of associated noise.

[0018] In a further aspect of the invention, it is provided that the one or more air baffles can extend in an arc from a central section of the air separation disc to an outer periphery of the air separation disc. Preferably, but not exclusively, the arc is open against the direction of rotation of the rotor. In a further aspect of the invention, it is provided that the one or more air baffles can be concavely shaped against the direction of rotation of the rotor. This advantageously supports the entrainment of the air accelerated by the rotor within the air flow channel. According to another aspect of the invention, which leads to the same advantages, the one or more air baffles can be arranged in a spiral shape.The entrainment of the air can be further improved by another aspect of the invention, according to which the air baffles can be tangential to an outer circumference of the air separation disc and wherein the air baffles can further describe a circular arc in the direction of the central portion of the air separation disc, preferably open against the direction of rotation of the rotor.

[0019] In a further aspect of the invention, it is provided that the air separation disc may have a central portion that is offset in an axial direction from an outer portion. This axial offset or this offset embodiment of the air separation disc may serve to increase the cross-section of the air flow channel defined by the air separation disc and is thus beneficial for air throughput and noise reduction, as the velocity of the air flowing through the air flow channel is reduced relative to the cross-sectional area of ​​the air flow channel.

[0020] According to another aspect of the invention, the one or more air baffles may have engagement features for a rotationally fixed connection of the air separation disc to the rotor chamber. In this way, the air separation disc is held in a rotationally fixed position relative to the rotor, whereby the aforementioned advantages are not reduced to a partial entrainment of the air separation disc in the rotational movement of the centrifuge rotor.

[0021] In a further aspect of the invention, it is provided that the air separation disc can have a through-opening arranged at the central section of the air separation disc, and the through-opening can be configured to guide a shaft of the centrifuge through. This arrangement offers a significant improvement in the design of a centrifuge with an air separation disc that defines an air flow channel in a rotor chamber, in particular when, according to a further aspect of the invention, the rotor chamber can be open at the top, and a chamber top can be covered by a lid, and the air inlet can be arranged in the lid. In particular, when it is provided that the air outlet can be arranged in a lower section of the chamber.According to another aspect of the invention, the air separation disc can be arranged between the lower section of the rotor chamber and the rotor, wherein the air inlet can be arranged in the lid of the centrifuge and the air outlet is arranged in the lower section of the rotor chamber. Essentially, the air separation disc can thus be arranged between an air outlet arranged in a bottom of a bowl-shaped rotor chamber and the rotor of the centrifuge, wherein the rotor is driven by a shaft extending through the rotor chamber bottom and the air separation disc. The bowl-shaped rotor chamber is closed at its opening at the top by a lid, wherein the lid has an air inlet. The air is thus accelerated by the rotor towards the radial walls of the rotor chamber and further guided through the air flow channel defined by the air separation disc and the bottom of the rotor chamber.Through the air inlet and the pressure difference created by the radial acceleration of the air entrained in the rotor chamber, new air is forced into the rotor chamber. The air separation disc serves to separate the radially outward airflow forced by the rotor rotation and the friction between the rotor and the air from an airflow within the air flow channel, which is directed radially inward toward the air outlet in the bottom of the rotor chamber.

[0022] According to another aspect of the invention, the air inlet and / or the air outlet can be arranged concentrically with the rotation axis. This further contributes to efficient air exchange, as the pressure minimum is located approximately at the rotation point, so that the air is efficiently drawn in through the air inlet and the rotating air is guided radially inward toward its rotation point without significant losses in airflow or generating unnecessary turbulence.

[0023] Consequently, while maintaining the aforementioned advantages, a further aspect of the invention provides that the air inlet, the air outlet, the rotor, the rotor chamber, and the air separation disc can form an air flow path from the air inlet through a gap between the rotor outer circumference and the axial walls of the rotor chamber above the air flow channel defined by the air separation disc to the air outlet. According to a further aspect of the invention, the air separation disc can separate the radially inwardly directed air between the air separation disc and the lower portion of the chamber from the rotor, and in particular from an end face of the rotor facing the lower portion of the chamber.The air separation disc thus serves to separate the air flow within the air flow channel and the rotating rotor and separates the air flow directed radially inwardly in the air flow channel towards the air outlet from any radially outwardly directed air flow caused by the air taken in by the rotor rotating during operation of the centrifuge.

[0024] In a further aspect of the invention, it is provided that an outer circumference of the air separation disc can correspond to a lower outer rotational circumference of the rotor, which improves the air inlet into the air flow channel defined by the air separation disc.

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

[0026] In a further aspect of the invention, it is provided that the air inlet can have a smaller diameter than the air outlet. Such dimensioning further improves the efficiency of air exchange, as it ensures that the air outlet does not represent a bottleneck. This prevents excess pressure buildup between the circumference of the rotor and the radial wall of the rotor chamber.

[0027] According to another aspect of the invention, the air outlet can be located on a circumference with respect to the rotor chamber, wherein this circumference can be smaller than the rotational circumference of the rotor. In a further aspect of the invention, it is provided that the air outlet can be an annular opening which can be delimited radially outwards by the rotor chamber and radially inwards by a shaft shroud of the centrifuge. According to a further aspect of the invention, the air separation disc can protrude radially between the lower section of the chamber and the rotor. In a further aspect of the invention, it is provided that the air separation disc can be in axial contact with the shaft shroud of the centrifuge.The use of such a design provides design advantages in terms of passing the rotor shaft and a bearing against the rotor housing, while maintaining a sufficiently large air outlet for efficient air removal from the rotor chamber.

[0028] In a further aspect of the invention, it is provided that the air can be guided through the air outlet of the rotor chamber and further guided around the motor and exit the centrifuge through an outlet opening. In this way, the air that is inadvertently drawn into the rotor chamber of the ventilated centrifuge can also serve to cool the motor. By guiding the air through the air duct and then to the air outlet to the motor, it is ensured that the motor does not preheat the air drawn into the air inlet.

[0029] According to a further aspect of the invention, the air separation disc can be arranged between the rotor and the lid, with the air inlet located in the lower section of the rotor chamber and the air outlet located in the lid of the centrifuge. Such a design may have advantages in certain applications where, for design or analytical reasons, it is not possible to introduce the ventilation air of a ventilated centrifuge from the lid side.

[0030] It will be apparent to one skilled in the art that the air separation disc, as described in the various embodiments above, may also constitute an independent device for improving the air flow within existing ventilated centrifuges.

[0031] The invention will now be described with reference to the following non-limiting figures. Further advantages of the disclosure will become apparent upon reference to the detailed description when considered in conjunction with the figures, in which: - Fig. 1 shows a schematic cross-section through a rotor chamber of a ventilated centrifuge, - Fig. 2 shows a perspective view of an air cutting disc, - Fig. 3 an air flow path in relation to the schematic cross section through a rotor chamber of a ventilated centrifuge according to Fig. 1 shows, and - Fig. 4 shows the air flow path through an air flow channel defined at least partially by the air separation disc in a bottom view of the air separation disc.

[0032] Fig. Figure 1 shows a sectional view of a centrifuge 1 with a rotor chamber 2, wherein the rotor chamber 2 contains a rotor 3 that is driven in rotation by a shaft 4 defining a rotation axis R. The centrifuge 1 comprises an air inlet 21 to the rotor chamber 2 and an air outlet 22 from the rotor chamber 2.

[0033] The rotor 3 is arranged axially between the air inlet 21 and the air outlet 22, and a rotationally fixed air separation disc 10 is arranged within the rotor chamber 2 between the air outlet 22 and the rotor 3. The air separation disc 10 is arranged concentrically with the rotation axis R, and an outer circumference 12 of the air separation disc 10 corresponds to a lower outer rotation circumference 32 of the rotor.

[0034] The rotor chamber 2 is open at the top, and a chamber top 23 is covered by a lid 25, and the air inlet 21 is arranged in the lid 25. The rotor chamber 2 is bowl-shaped, and the air outlet 22 is arranged in a lower section 24 of the chamber 2. The air inlet 21 and the air outlet 22 are arranged concentrically with the rotation axis R as well as with the rotor 3 and the air separation disc 10.

[0035] The air separation disc 10 is in axial contact with a shaft cover 42 of the centrifuge and projects radially between the lower section 24 of the chamber 2 and the rotor 3.

[0036] Now with reference to the Fig. 2 and Fig. 4, the air separation disc 10 defines an air flow channel 13 from a radially outer periphery 12 of the air separation disc 10 radially inward toward a central portion 15 of the air separation disc 10. The air flow channel 13 also consists of a plurality of air deflectors 11a-d formed as projections relative to the rotational axis R, which projects axially from the radially extending air separation disc 10. The air deflectors 11a-d are formed integrally with the air separation disc 10 and have a bevel or radius 14 between the air separation disc 10 and its axial projection.

[0037] The air baffles 11a-d extend in an arc shape from a center 15 of the air separation disc 10 to an outer circumference 12 of the air separation disc, in particular and as can be seen from Fig. 2 and Fig. 4, the air baffles 11a-d are tangential to the outer circumference 12 of the air separation disc 10 and are arranged spirally and open against the direction of rotation D of the rotor 3. The air baffles 11a-d have engagement features 17, designed here as receptacles for bolts, for a rotationally fixed connection of the air separation disc 10 to the rotor chamber 2. The central section 15 of the air separation disc 10 is offset from an outer section 16 of the air separation disc 10 in an axial direction. The center 15 of the air separation disc 10 has a through opening 18, which, as in Fig. 1 and Fig. 3, is configured to feed the shaft 4 to the centrifuge 11.

[0038] How best to use the Fig. 3 and Fig. 4, the air inlet 21, the air outlet 22, the rotor 3, the rotor chamber 2 and the air separation disc 10 form an air flow path 6 from the air inlet 22 through a gap 35 between the outer circumference 32 of the rotor 3 and the axially extending wall 26 of the rotor chamber 2 and further via the air flow channel 13 to the air outlet 22.

[0039] The air separation disc 10 separates the radially inwardly guided air between the air separation disc 10 and the lower section 24 of the rotor chamber 2 from the rotor 3 and in particular from an end face 36 of the rotor 3 facing the lower section 24 of the chamber 2.

[0040] How to continue Fig. 3, the air separation disc 10 guides the air flow axially downwards towards the air outlet 22 and the air baffles 11a-d extend both radially outwards and radially inwards beyond the air outlet 22. As further shown in Fig. 3, 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 which is smaller than the cross-sectional area of ​​the air outlet 22, although the air outlet 22 is designed as an annular opening which is bounded radially outwards by the rotor chamber 2 and radially inwards by the shaft covering 42 of the centrifuge 1.

[0041] As from Fig. 3, the air is guided through the air outlet 22 of the rotor chamber 2 and can thus be further guided around a motor of the centrifuge and can leave the centrifuge 1 through an outlet opening, while both the motor and the outlet opening of the centrifuge 1 are not shown in the drawings.

[0042] It is to be understood that the present disclosure is not limited to the embodiments described above, and that modifications and variations of the embodiments described above will be readily apparent to those skilled in the art.

[0043] For example, it is possible to arrange the air separation disc between the rotor and the lid, with the air inlet located in the lower section of the rotor chamber and the air outlet located in the lid of the centrifuge. The air flow path would then run from the bottom of the rotor chamber through the gap between the axial wall of the rotor chamber and then through the air separation disc into the air guide channel between the air separation disc and the lid. Such an embodiment may have advantages in certain applications where, for design or analytical reasons, it is not possible to introduce the ventilation air of a ventilated centrifuge from the lid side.

[0044] Features of the above-described embodiments may be combined in any suitable combination with features of other above-described embodiments as would be readily apparent to one skilled in the art, and the specific combinations of features described in the above embodiments should not be construed as limiting. List of reference symbols 1 centrifuge 2 rotor chamber 3 Rotor 4th wave 10 air cutting disc 11a-d Air baffles 12 Outer circumference (of the air cutting disc) 13 Air flow channel 14 Bevel, radius 15 Middle section (of the air cutting disc) 16 Outer section (of the air separation disc) 17 intervention characteristics 18 passage opening 21 Air intake 22 Air outlet 23 Chamber top 24 Lower Section 25 lids 26 Axial wall 32 Outer circumference of rotation (of the rotor) 35 gap 36 Front side (of the rotor) 42 Shaft cover R axis of rotation D Direction of rotation

Claims

[1] Centrifuge (1) having a rotor chamber (2) containing a rotor (3) driven in rotation by a shaft (4) defining a rotation axis (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), characterized by in that a rotationally fixed air separation disc (10) is arranged within the rotor chamber (2) between the air outlet (22) and the rotor (3), and the air separation disc (10) defines an air flow channel (13) from a radially outer circumference (12) of the air separation disc (10) radially inward to a central portion (15) of the air separation disc (10). [2] Centrifuge (1) according to claim 1, wherein the air separation disc (10) is arranged concentrically with the axis of rotation (R) and the air separation disc (1) has one or more air baffles (11a-d) for deflecting air. [3] Centrifuge (1) according to claim 2, wherein the one or more air baffles (11a-d) are arranged spirally and the one or more air baffles (11a-d) are tangential to an outer circumference of the air separation disc (10). [4] Centrifuge (1) according to one of claims 2 or 3, wherein the one or more air baffles (11a-d) have engagement features (17) for a rotationally fixed connection of the air separation disc (10) to the rotor chamber (2). [5] Centrifuge (1) according to one of the preceding claims, wherein the air separation disc (10) has a through-opening (18) arranged at the central portion (15) of the air separation disc (10), and the through-opening (18) is adapted to guide the shaft (4) of the centrifuge (1) therethrough. [6] Centrifuge (1) according to one of the preceding claims, wherein the air inlet (21) and / or the air outlet (22) are arranged concentrically with the axis of rotation (R). [7] Centrifuge (1) according to one of the preceding claims, wherein the air inlet (21), the air outlet (22), the rotor (3), the rotor chamber (2) and the air separation disc (10) form an air flow path from the air inlet (21) arranged in a lid (25) of the centrifuge (1), through a gap (35) between the outer circumference (32) of the rotor and an axial wall (26) of the rotor chamber (2) via the air flow channel (13) defined by the air separation disc (10) to the air outlet (22) arranged in a lower portion (24) of the rotor chamber (2). [8] Centrifuge (1) according to one of the preceding claims, wherein the air separation disc (10) separates the radially inwardly guided air between the air separation disc (10) and the lower portion (24) of the chamber (2) from the rotor (3). [9] Centrifuge (1) according to one of the preceding claims, wherein an outer circumference (12) of the air separation disc (10) corresponds to a lower outer rotational circumference (32) of the rotor (3). [10] Centrifuge (1) according to one of the preceding claims, wherein the air outlet (22) is located on a circumference with respect to the rotor chamber (2), said circumference being smaller than the rotational circumference (32) of the rotor (3). [11] Centrifuge (1) according to one of the preceding claims, wherein the air outlet (22) is an annular opening which is bounded radially outwards by the rotor chamber (2) and radially inwards by a shaft cover (42) of the centrifuge (1). [12] Centrifuge (1) according to one of the preceding claims, wherein the air separation disc (10) projects radially between the lower portion (24) of the rotor chamber (2) and the rotor (3). [13] Centrifuge (1) according to one of the preceding claims, wherein the air separation disc (10) is in axial contact with the shaft cover (42) of the centrifuge (1). [14] Centrifuge (1) according to one of the preceding claims, wherein the air guided through the air outlet (22) of the rotor chamber (2) is further guided around a motor of the centrifuge (1) and leaves the centrifuge (1) through an outlet opening. [15] Centrifuge (1) according to one of claims 1 to 7 or 9 to 13, wherein the air separation disc (10) is arranged between the rotor (3) and the lid (25), wherein the air inlet (21) is arranged in the lower section (24) of the rotor chamber (2) and the air outlet (22) is arranged in the lid (25) of the centrifuge (1).

Images