EP4151315A1 - Centrifuge and method for cleaning a centrifuge - Google Patents

Abstract

The invention relates to a centrifuge (1) for cleaning a reaction vessel unit (7) and a method for cleaning such a centrifuge. The centrifuge (1) has a rotor (2) and a rotor space (9) in which the rotor is arranged and rotatably mounted, the rotor (2) having a receiving area (6) for receiving the reaction vessel unit (7). The rotor space (9) is delimited by a housing (3), the housing having an outlet to drain liquid discharged from the reaction vessels and an inlet to fill the rotor space with a cleaning solution in such a way that when the rotor turns this is at least partially immersed in the cleaning solution and this is distributed in the rotor space and/or the inlet is designed in such a way that the cleaning solution is distributed in the rotor space when it is supplied by the rotating rotor.

Description

The present invention relates to a centrifuge for cleaning a reaction vessel unit with a rotor and a rotor space in which the rotor is arranged and rotatably mounted, the rotor having a receiving area for receiving the reaction vessel unit. Furthermore, the invention relates to a method for cleaning such a centrifuge.

The EP 937502 A2 describes a method for handling a microtiter plate, wherein the microtiter plate is cleaned by means of centrifugation. For this purpose, the microtiter plate is placed in the rotating housing via a conveyor belt so that the openings of the microtiter plate are directed away from the axis of rotation.

From the WO 2015/018878 A1 another centrifuge emerges, which has an elastic arm with which microtiter plates can be drawn into a rotor of the centrifuge or from which this rotor can be pushed. The rotor has only a very small distance to the surrounding housing and also to the drainage channel arranged in the lower area. This short section is intended in order to drive the liquid that has escaped from the reaction vessels into the drainage channel with the resulting circulation wind and then to pump it out by means of a pump. Due to the small distance, there is a risk that the liquid level will be above the drainage channel. This allows the rotor to dip into the liquid as it rotates. This is particularly critical when the liquid is a washing solution containing detergents, since the rotor then beats the liquid into foam. This foam can quickly fill most of the volume of the rotor and exit at the door. Also, the foaming material cannot be pumped out well by the pump described, but rather remains in the rotor space or in the drainage channel. The close distance of the rotor to the drainage channel results primarily from the cylindrical shape of the rotor space, which is selected in such a way as to generate the desired circulation wind.

It is known that in the case of cylindrical rotor chambers of centrifuges, circulation winds arise due to the rotating rotor. In this context, the US 2007/0037684 A1 , DE 103 55 179 A1 , DBP 1033446 , EP 2 705 903 A1 and DE 2404036 referred.

From the WO 2018/234420 A1 another centrifuge for cleaning reaction vessel units emerges. This centrifuge has a rotor and a rotor space in which the rotor is rotatably mounted. A reaction vessel assembly is inserted into the centrifuge with its openings facing outwards so that as the rotor rotates, the reagents therein are expelled from the respective reaction vessels. As a result, the reaction vessels can be cleaned essentially without residue. This centrifuge can. Have dispensing unit, wherein the dispensing unit has a plurality of dispensing nozzles. The dispensing nozzles are preferably arranged next to one another along a line, this line extending transversely to the direction of movement of the reaction vessel unit when loading or unloading the centrifuge. The nozzles of the dispensing unit are arranged adjacent to an opening for loading and unloading the centrifuge with the reaction vessel unit.

From the WO2017/125598 A1 discloses yet another centrifuge which in turn has a loading and unloading device in which reaction vessel units are positioned by means of a rigid displacement rod.

CN 102175855A reveals a fully automatic 360° plate washing machine. The axis of rotation of this machine runs parallel to the horizontal plane, allowing several plates to be washed simultaneously in one housing, increasing efficiency and greatly reducing costs.

U.S. 4,953,575 relates to a washing device for cuvettes. For this purpose, the cuvettes are placed in a holder in a rotor. The liquid is removed from the cuvettes by turning the rotor. The disclosed centrifuge housing has an opening at its lowest point through which the removed liquid can leave the housing.

JP 2009264927 A discloses an apparatus comprising a drum in which a microplate can be placed. The drum can be loaded with several microtiter plates, which then turn around a horizontal axis of rotation. The drum is loaded with the microtiter plate in such a way that its openings are directed towards the interior of the drum.

The JP 2007/178355 A discloses a system for cleaning printed circuit boards in which one or more microtiter plates are placed in a rotary unit whose axis of rotation is vertical. The device has a number of nozzles which can spray the microtiter plates with a cleaning liquid from the outside.

The invention is based on the object of creating a centrifuge for cleaning a reaction vessel unit, which has a rotor and a rotor space in which the rotor is rotatably mounted, with the centrifuge contamination being avoided and reliable operation being possible over the long term .

The object is solved by the subject matter according to the independent patent claims. Advantageous refinements of the invention are specified in the respective dependent claims.

A centrifuge according to the invention for cleaning a reaction vessel unit has a rotor and a rotor space in which the rotor is arranged and mounted, the rotor having a receiving area for receiving the reaction vessel unit. The rotor space is delimited by a housing, the housing having an outlet to drain liquid discharged from the reaction vessels and is provided with an inlet to fill the rotor space with a cleaning solution in such a way that the cleaning solution can be removed by turning the rotor without reaction vessel units in the rotor space is distributed through contact with the rotor so that the rotor space is cleaned. The axis of rotation of the rotor runs parallel to a base.

A cleaning solution can thus be supplied to this centrifuge and distributed in the rotor space. The rotor is used to distribute the cleaning solution. This is discussed further below in explaining the procedure for cleaning the centrifuge.

When the rotor rotates, it can at least partially dip into the cleaning solution and distribute it in the rotor space and/or the inlet is designed such that the cleaning solution is distributed in the rotor space when it is fed in by the rotating rotor. The cleaning solution can come into contact with the rotor and be distributed by the centrifugal forces occurring on the rotor and/or be carried along by the air flow generated by the rotor and thereby distributed.

Due to the fact that the axis of rotation of the rotor runs parallel to a standing surface, the cleaning solution is distributed in the entire rotor space when the rotor space is partially filled by the partial immersion of the rotor in the cleaning solution. It is not necessary to completely fill the entire rotor chamber with the cleaning solution. Therefore, the rotor space does not have to be perfectly sealed. Furthermore, in contrast to an arrangement in which the axis of rotation of the rotor runs perpendicularly to a standing surface, the cleaning solution is not only distributed radially outwards by centrifugal force without being distributed throughout the rotor space.

Due to the parallel alignment of the axis of rotation and the immersion, the cleaning solution in the rotor chamber is carried upwards by the rotor and is evenly distributed in the rotor chamber by the resulting air flow.

When cleaning a reaction vessel unit in a centrifuge, in which the contents of the reaction vessels are thrown out of the reaction vessels of the reaction vessel unit, there is a risk that residues of the contents of the reaction vessels will remain in the rotor space and possibly be transferred to another reaction vessel unit. This is critical above all when chemical or biological samples are contained in the reaction vessel units. For biological samples, a single molecule, such as a segment of a DNA strand, transferred to another reaction vessel assembly can represent an intolerable contamination.

Such centrifuges for cleaning a reaction vessel unit are now being used with great success. However, they must be cleaned at regular intervals. The design of the centrifuge according to the invention allows the centrifuge to be cleaned independently or automatically. As a result, the centrifuge can be part of an automatic process and can be subjected to a cleaning process from time to time without an operator having to intervene manually. For example, the centrifuge can be cleaned several times in a work cycle lasting several hours without anyone having to intervene manually. This is a significant advantage over conventional centrifuges for cleaning reaction vessel assemblies.

The outlet of the housing can also form the inlet. For example, an opening in the housing, which forms the outlet or the inlet, can be connected to a fluid line which has a branch, so that the fluid line branches into an inlet line and an outlet line. The drain line is designed to drain a fluid and the inlet line is designed to supply a fluid. The drain line has a blocking element for blocking the drain line. If the outflow line is blocked by the blocking element, the fluid or a cleaning solution can be supplied via the inflow line without it flowing out via the outflow line and being fed exclusively to the rotor space.

The blocking element can be a valve or a hose clamp that can preferably be actuated automatically if at least part of the discharge line is designed as a hose. The hose clamp can be provided with an actuator to operate it automatically. The actuator can be designed as an eccentric or as an electric or pneumatic piston mechanism.

The feed line can also be fluidically coupled to a dispensing device integrated in the centrifuge, so that the feed line can be supplied with a cleaning solution by means of the dispensing device. In such an embodiment of the centrifuge, the dispensing device has both the function of dispensing solutions into reaction vessels of the reaction vessel units and of supplying the cleaning solution to the rotor space.

The outlet can be provided with a suction pump and a siphon, the siphon being designed in such a way that when the suction pump is not actuated, a liquid with a filling level below a predetermined filling level remains in the rotor chamber. As a result, by not actuating the suction pump, it can be ensured that a cleaning solution present in the rotor space remains in the rotor space, provided the level of the cleaning solution is not above the predetermined level. The level of this predetermined filling level is preferably selected in such a way that a rotor dips into the liquid as it rotates and at least partially takes it with it. The siphon thus forms the blocking element with which the discharge line is blocked up to a specific fill level if the suction pump is not actuated.

A filling level sensor for detecting the filling level can be provided in the rotor space. The level sensor can be an ultrasonic sensor with which the surface of the liquid is scanned. It is advisable to turn the rotor into a position so that it does not impede the measurement. The fill level can also be formed by one or more temperature sensors, which are attached to the inner surface of the housing and are used to measure a particular level of the liquid.

The inlet can be arranged above an axis of rotation of the rotor, so that when the cleaning solution is fed in, it can come into contact with the rotor. The rotor can of course be in a position where it does not come into contact with the cleaning solution fed by the inlet, for example when it is oriented vertically. As a result, a cleaning liquid supplied in this way is carried along by a rotating, in particular rapidly rotating, rotor and is distributed in the rotor chamber. Low speeds of a few rpm are already sufficient for this. As a rule, the rotor is rotated at speeds of at least 10 rpm or at least 50 rpm or more. The rotor should not be spun faster than 100 rpm when the cleaning solution has been introduced into the rotor chamber to a predetermined level so that the rotor can be immersed in the cleaning solution. If, on the other hand, the cleaning solution is introduced into the rotor space, for example by atomization, without the cleaning solution collecting at the bottom of the rotor space, then the rotor can also be operated at higher speeds of, for example, at least 100 rpm. In this case, speeds of at least 500 rpm or at least 1000 rpm can also be expedient.

The inlet can also have one or more nozzles in order to atomize the cleaning solution into the rotor space. A cleaning liquid which is atomized in the rotor space in this way can also be distributed uniformly in the rotor space by turning the rotor.

• Der Rotorraum wird mit einer Reinigungsflüssigkeit entweder mindestens bis zu einem vorbestimmten Niveau gefüllt, so dass beim Drehen des Rotors dieser zumindest teilweise in die Reinigungslösung eintaucht, und/oder die Reinigungslösung wird dem Rotorraum so zugeführt, dass sie entweder mit dem Rotor in Kontakt kommen kann und/oder in einen Bereich des Rotorraums eingebracht wird, in dem sie bei drehenden Rotor von einem Luftstrom mitgenommen wird,
• der Rotor wird gedreht / bewegt, wodurch die Reinigungslösung im Rotorraum verteilt wird, und
• die Reinigungslösung wird aus dem Rotorraum entfernt.

Another aspect of the invention relates to a method for cleaning a centrifuge for cleaning a reaction vessel unit, the centrifuge having a rotor and a rotor chamber in which the rotor is arranged and rotatably mounted, the rotor having a receiving area for receiving the reaction vessel unit and the Axis of rotation of the rotor runs parallel to a base. This procedure involves the following steps:

• The rotor chamber is either filled with a cleaning liquid at least to a predetermined level, so that when the rotor rotates, it is at least partially immersed in the cleaning solution, and/or the cleaning solution is fed to the rotor chamber in such a way that it can either come into contact with the rotor and/or is introduced into an area of the rotor space in which it is entrained by an air flow when the rotor is rotating,
• the rotor is turned / moved, which distributes the cleaning solution in the rotor chamber, and
• the cleaning solution is removed from the rotor space.

When the cleaning solution is removed, the impurities in the rotor space are taken with it. The cleaning solution can flow off via the drain and thus be removed from the rotor space. This can be controlled, for example, by opening a blocking element in a drain line.

The rotor has two functions in such a centrifuge. On the one hand, the rotor serves to empty the reaction vessel units, in that the contents are thrown out of the individual reaction vessels of the reaction vessel units by rotating the rotor. On the other hand, the rotor also serves to distribute the cleaning solution in the rotor space and thus to clean the rotor space evenly and reliably. On the one hand, the cleaning solution can be distributed by the rotor being at least partially immersed in the cleaning solution during rotation and taking it with it. However, the cleaning solution can also be supplied in such a way that it is entrained directly by the rotor or by the draft generated by the rotor and is distributed in the rotor space. This applies in particular when the cleaning solution is atomized into the rotor space, then a mist of the cleaning solution is evenly distributed in the rotor space by turning the rotor.

The cleaning solution can be a non-foaming cleaning solution containing, for example, formaldehyde or paraformaldehyde. Such a non-foaming cleaning solution can run off the rotor space independently, without further activities. Spinning of the rotor can serve to force the cleaning solution to drain and remove it from the rotor space. However, the cleaning solution can also drain off automatically when the rotor is at a standstill if the drain line is unlocked accordingly.

The cleaning solution can also be a foaming cleaning solution, in particular a cleaning solution containing surfactants. When the cleaning solution is distributed through the rotor, the cleaning solution foams in the rotor space. To remove the foamed cleaning solution, a foam-degrading solution, which contains alcohol, for example, can be supplied to the rotor space. This causes the foam to collapse and flow out through the drain. The draining or removal of the cleaning solution from the rotor chamber can also be supported here by turning the rotor, just as with the non-foaming cleaning solution.

The defoaming solution can also be distributed in the rotor space during or after the feeding by rotating the rotor to effectively distribute the defoaming solution in the rotor space.

A centrifuge as explained above can be used in this method.

• Figur 1 ein Teil eines Gehäuses einer Zentrifuge in perspektivischer Ansicht,
• Figur 2 das Teil des Gehäuses aus Figur 1 in einer Schnittansicht mit Blickrichtung von schräg vorne,
• Figur 3 das Teil des Gehäuses aus Figur 1 in einem Längsschnitt,
• Figur 4a die Zentrifuge nach einem ersten Ausführungsbeispiel mit dem Gehäuseteil aus Figur 1 in einem Längsschnitt, und
• Figur 4b die Zentrifuge nach einem zweiten Ausführungsbeispiel mit dem Gehäuseteil aus Figur 1 in einem Längsschnitt.

The invention is explained in more detail below by way of example with reference to the drawings. The drawings show in:

• figure 1 a part of a housing of a centrifuge in a perspective view,
• figure 2 the part of the housing figure 1 in a sectional view looking diagonally from the front,
• figure 3 the part of the housing figure 1 in a longitudinal section,
• Figure 4a the centrifuge according to a first embodiment with the housing part figure 1 in a longitudinal section, and
• Figure 4b the centrifuge according to a second embodiment with the housing part figure 1 in a longitudinal section.

A centrifuge 1 according to the invention ( Figure 4a ) has a rotor 2, a housing 3, a drive device 4 for rotating the rotor 2 about an axis of rotation 5.

The rotor has at least one receiving area 6 for receiving a reaction vessel unit 7. The reaction vessel unit 7 is usually a microtiter plate. Such microtiter plates can be designed with a different number of reaction vessels. Microtiter plates with six to 4096 wells are common, with microtiter plates with 96, 384 or 1536 wells being the most common versions. In the case of microtiter plates with 384 or 1536 reaction wells, the individual reaction wells are so thin that a liquid normally adheres therein due to capillary forces alone, so that even if such a microtiter plate is arranged with its openings down, the liquid does not flow out. For microtiter plates with fewer reaction vessels, each larger, this does not apply. Such a reaction vessel unit 7 can be inserted alone into a receiving area 6 or on a carrier unit. A carrier unit is preferably used which has a coupling element which can be coupled to a loading and unloading device 8 . Such a loading and unloading device is for example in DE 10 2016 101163 described. It is explained in more detail below.

The housing 3 delimits a rotor chamber 9. In the present exemplary embodiment, the region of the housing 3 delimiting the rotor chamber 9 is formed from a lower shell 10, an upper shell 11, a front end wall 12 and a rear end wall 13. Further parts of the housing, which are not shown in the accompanying figures, are connected to the rear end wall.

In the front end wall 12 and rear end wall 13 are each a ball bearing 14, in which a continuous shaft 15 of the rotor 2 is rotatably mounted. The center line of the shaft 15 forms the axis of rotation 5. The axis of rotation 5 runs parallel to a standing surface 16 which is formed by the underside of the lower shell 10.

The rear end of the shaft 15 is coupled to the driving device 4 . The other part of the housing, which adjoins the rear of the housing, contains the drive device 17, the loading and unloading device 8 and a central control device (not shown) with which all the components of the centrifuge 1 are controlled.

A balcony 18 is attached to the outside of the front end wall 12 and serves to accommodate a reaction vessel unit 7 . At the level of the balcony 18, a loading and unloading opening 19 is formed in the front end wall 12, through which a reaction vessel unit 7 can be inserted into the rotor chamber 9 and pushed out again. The loading and unloading opening 19 is provided with a hinged door 20 so that the rotor space can be closed.

A dispensing unit 39 with a plurality of dispensing nozzles 40 and/or an optical detection unit, in particular in the form of a line camera, can be provided adjacent to this door 20 .

The loading and unloading device 8 has a displacement rod (not shown), which can be moved horizontally through the rotor space 9 with its free end through a through-opening 21 in the rear end wall 13 . For this purpose, the loading and unloading device 8 has a linear drive, so that the displacement rod can be moved linearly along its longitudinal direction. The sliding rod has at its free end a coupling element which can be coupled to a corresponding coupling element on the carrier unit or on a reaction vessel unit 7, so that the carrier unit can be coupled to a reaction vessel unit or the reaction vessel unit directly by moving the sliding rod from the balcony 18 through the loading and unloading opening 19 into the rotor space 9 can be moved, the rotor 2 being arranged here with a receiving area 6 adjacent to the loading and unloading opening 19, so that the carrier unit or the reaction vessel unit is displaced into the receiving area 6 of the rotor 2. The coupling between the displacement rod and the carrier unit or the reaction vessel unit 7 can be released so that the carrier unit or the reaction vessel unit is freely movable in the rotor 2 and the rotor can be rotated accordingly with this unit.

The carrier unit or reaction vessel unit 7 can be pushed out of the receiving area 6 of the rotor 2 through the loading and unloading opening 19 back onto the balcony 18 by means of the sliding rod of the loading and unloading device 8 . The reaction vessel unit 7 can be removed from the balcony 18 by means of a robot, for example.

The lower shell 10 has a channel 22 which runs approximately parallel to the axis of rotation 5 . The channel 22 extends from the rear end wall 13 to the area of the front end wall 12, whereby it is designed to be inclined or sloping towards the front ( Figure 4a ). An outlet opening 23 is formed on the front side of the lower shell 10, at which the channel 22 opens. A connecting pin 24 is arranged at the outlet opening 23, to which a hose 25 can be connected. The hose 25 usually ends in a receptacle (not shown) in which the liquids that are spun out of the reaction vessels of the reaction vessel unit 7 in the centrifuge 1 are received. The container preferably has a ventilation opening, or the tube passes through the container with some play, so that liquid running out of the centrifuge through the tube 25 does not generate any back pressure in the container.

The lower shell 10 has inner surfaces adjoining the channel 22, which each extend obliquely upwards from an upper edge of the channel 22 ( 2 ). These inner surfaces thus form a funnel 26 and are referred to as funnel surfaces 27 below. The funnel surfaces 27 are inclined at an angle of approximately 30° to 60° to the horizontal. Substantially planar means that the funnel surfaces have a radius of curvature of more than 0.5 m and preferably more than 1 m. The funnel surfaces 27 in the present embodiment extend laterally in a direction beyond the area of the rotor 2, even when it is in its horizontal position.

The inner surfaces of the lower shell 10 extend approximately vertically upwards from the outer edge of the funnel 26 or the funnel surfaces 27 . They thus form vertical surfaces 28.

Attached to the upper edge of the lower shell 10 is the upper shell 11, which has a groove-like shape with a semi-circular shape in cross section. The inner surface of the upper shell 11 merges flush with the vertical surface 28 . The cross section of the housing 3 is therefore not cylindrical, but has a cylindrical curvature only in the upper area of the shell 11 , whereas the lower shell 10 has a funnel-shaped cross section and ends in the channel 22 . The trough 22 is slightly offset downwards from the funnel-shaped lower shell 10 and has two approximately vertically arranged side walls 37a, 37b. The channel itself is designed with an incline so that any liquid contained therein runs off.

In the present exemplary embodiment, the lower shell 10 and the upper shell 11 are made of metal. The inner surfaces of the lower shell 10 and the upper shell 11 are coated with a smooth layer of plastic, so that liquids thrown out of the reaction vessels of the reaction vessel units 7 run off quickly along the inner surfaces, from the funnel 26 to the channel 22 and from there out of the Rotor space 9 emerge. The plastic layer is made of PTFE.

The upper edge of the channel 22 is spaced from the axis of rotation 5 by at least 1.32 times the maximum radius of the rotor 2 . As a result, a free space is formed in the funnel 26, which is not touched by the rotor 2 during one revolution. Liquid can collect in this free space. In figure 2 a maximum level 29 of the liquid that can accumulate in the funnel 26 without coming into contact with the rotor is indicated. This makes it possible, in the case of large-volume reaction vessels of a reaction vessel unit 7 , to empty the main part of the liquid contained therein all at once, to collect it in the funnel 26 so that it can gradually flow out through the outlet opening 23 .

Furthermore, due to the large distance between the trough 22 and the rotor and the resulting large cross-section, the air flow generated by the rotor when rotating is lowest in this area, so that liquid can settle on the bottom of the funnel, i.e. in the trough 22, and flow out of the Channel 22 flows out through the outlet opening 23. Because of the low flow rate, there is also little risk of liquids located in the funnel-shaped area adjacent to the channel 22 being driven upwards by the air flow.

Since the trough is delimited by approximately vertical side walls 37a, 37b, even if an air flow is generated in the direction of rotation 38, the liquid can no longer flow out of the trough to drive. A liquid once in the channel 22 is thus trapped therein and can only escape through the outlet opening 23 . At the in figure 2 In the exemplary embodiment shown, an air flow can strike the side wall 37a, which is arranged below in the channel 22 in the direction of rotation 38 of the rotor. But since the side wall 37a is approximately perpendicular to the direction of flow, the liquid in the channel can no longer be driven back into the rotor space. In principle, a trough with an approximately vertical side wall on the side of the trough 22 that follows in the direction of rotation 38 is sufficient. In terms of manufacturing technology, however, it is expedient to produce a trough with two approximately vertical side walls 37a, 37b.

This design of the funnel 26 and the channel 22 makes it unnecessary to use a suction pump.

The dispensing unit 30, which can also be referred to as a dispensing head, has a plurality of dispensing nozzles 31, which are arranged along a straight line and point with their openings downwards. The dispensing unit 30 is connected to a reagent line 32 via which the dispensing unit 30 is supplied with reagents which are then distributed downwards via the individual dispensing nozzles 31 . The dispensing unit basically has the WO 2018/234420 A1 known function that reaction vessels of a reaction vessel unit 7 can be filled with reagents when the reaction vessel unit 7 is moved past the dispensing unit 30 by means of the loading and unloading device 8 .

In the first embodiment of the present invention ( Figure 4a ) the balcony 18 is formed in the area below the dispensing unit 30 with a channel 33 which is open at the top and in which the reagents dispensed by the dispensing nozzles 31 are collected if no reaction vessel unit 7 is arranged below the dispensing nozzles 31, as is the case in Figure 4a is shown. The channel 33 communicates with a collecting tube 34 so that the reagents collected in the channel 33 flow off via the collecting tube 34 . The collecting hose 34 opens into the hose 25 at a branch 35. With regard to the rotor chamber 9, starting from the branch 35, the collecting hose forms an inlet line and the hose 25 forms an outlet line for discharging liquids from the rotor chamber 9. The hose 25 is downstream of the branch 35 a blocking element 36 is arranged, with which the passage of the hose 25 can be blocked. The blocking element 36 can be a preferably electrically operable valve in order to open or close the passage of the tube. The blocking element can also be a hose clamp, which can be opened or closed, for example, with an actuator or by means of an eccentric.

If the blocking element 36 blocks the passage of the hose 25 and a cleaning solution is supplied with the dispensing unit 30 via the collecting hose 34, then the cleaning solution flows via the hose 25 and the outlet opening 23 into the rotor chamber 9. The outlet opening 23 then serves as an inlet for the cleaning solution. In principle, it would be possible to supply cleaning solution to the rotor space 9 up to the level of the upper side of the balcony 18 . However, it is advisable not to flood the ball bearings 14 of the shaft 15 with cleaning solution. The rotor space 9 is above the level 29 ( figure 2 ) filled with cleaning solution, so that when the rotor 2 rotates, it is immersed in the cleaning solution and takes part of the cleaning solution with it and distributes it in the rotor space 9 . In practice it has been shown that the rotor space 9 is at least filled up to a level 43, as is the case figure 2 is shown. The level 43 is about 5% of the radius of the rotor 2 and preferably at least 10% of the radius of the rotor 2 above the level 29, which is just not touched when the rotor 2 rotates.

The cleaning solution is distributed in the rotor chamber 9 by turning the rotor 2, so that all points of the rotor chamber 9 come into contact with the cleaning solution.

While the cleaning solution is being distributed by rotating the rotor 2, cleaning solution can continue to be supplied via the dispensing unit 30 in order to slow down or avoid the lowering of the level of the cleaning solution.

If the cleaning solution is sufficiently distributed in the rotor chamber 9, then a predetermined period of time can be waited for so that the cleaning solution can absorb the impurities. Here, the rotation of the rotor can be stopped or the rotor can be rotated further in order to cause a continuous turbulence of the cleaning solution in the rotor space by the draft of air.

Once this cleaning step has ended, the blocking element 36 is opened so that the cleaning solution runs off through the outlet opening 23 . This can be assisted by turning the rotor further so that the cleaning solution is driven into the channel 22.

This cleaning process of the rotor space 9 can be carried out fully automatically and is controlled by the central control device.

A non-foaming cleaning solution, such as formaldehyde or paraformaldehyde, is preferably used as the cleaning solution, with which the entire rotor chamber 9 can be reliably disinfected.

In the case of biological samples, in particular samples containing bacteria, however, it is advantageous if the cleaning solution contains surfactants which cause the cleaning solution to foam when the rotor is rotated. A foaming of the cleaning solution causes a very fast and uniform distribution of the cleaning solution in the rotor space 9, which is why the rotational speed and/or duration at which the rotor is rotated in the rotor space 9 can or should be significantly reduced compared to the distribution of non-foaming cleaning solution. In order to completely remove the foamed cleaning solution from the rotor chamber 9 again, a foam-degrading solution is fed to the rotor chamber 9 via the dispensing unit 30 and the collecting hose 34 and distributed by rotating the rotor 2 . As a result, the foam in the rotor space 9 collapses and the cleaning solution flows out of the rotor space 9 together with the solution that breaks down the foam. Such a defoaming solution may contain, for example, alcohol. A solution containing alcohol also has the advantage that it evaporates very quickly and the rotor space 9 dries accordingly quickly as a result.

A second embodiment of the centrifuge 1 ( Figure 4b ) is designed essentially the same as the first exemplary embodiment, unless otherwise explained below, which is why identical parts are provided with the same reference symbols and are not explained again. The second exemplary embodiment does not have to have a dispensing unit. A feed opening 39 is formed on the rear end wall 13 in the area above the shaft 15 , which is connected to the reagent line 32 and opens into the rotor space 9 . In the present exemplary embodiment, an atomizing nozzle 40 is arranged in the supply opening 39 and is used to atomize reagents supplied via the reagent line 32 into the rotor space 9 . By supplying a cleaning solution via the supply opening 39, this is introduced into the rotor space 9 and atomized by the atomizing nozzle 40 to form a mist, which is evenly distributed in the rotor space 9 by rotating the rotor 2. Part of the cleaning solution settles in the channel 22 and runs out of the rotor chamber 9 via the outlet opening 23 and the hose 25 . As a result, cleaning solution can be continuously circulated and discharged in the rotor space 9 in order to remove contamination from the rotor space 9 . A blocking element 36 can optionally be provided in the hose 25 in order to block the passage of the hose 25 and retain cleaning solution in the rotor space 9 .

It can also be expedient to turn the rotor alternately in different directions of rotation during the cleaning process in order to achieve the most uniform possible distribution of the cleaning solution in the rotor chamber.

In principle, it is also possible not to arrange an atomizing nozzle 40 in the feed opening 39 . This depends on the dimensions of the rotor space, the rotor and the air flow generated thereby during the turning of the rotor. Adequate distribution of the cleaning solution can thus be achieved simply by turning the rotor and the air flow generated thereby, without the need for atomizing nozzles. On the other hand, it can also be useful several feed openings 39, in particular also to be provided on the upper shell 11, in order to achieve an even distribution over the entire width of the rotor chamber 9 in the direction of the axis of rotation 5.

A pressure nozzle can also be inserted into the feed opening(s) 39 . A pressure nozzle is a nozzle that opens when the cleaning solution is supplied to the nozzle at a predetermined pressure. In this way, the point in time at which the cleaning solution is fed into the rotor space can be precisely controlled. The pressure nozzle can also be an atomizing nozzle.

Furthermore, in the second exemplary embodiment, when the blocking element 36 is provided in the hose 25, cleaning solution can be introduced into the rotor chamber 9 via the feed opening 39 until a filling level corresponding to the level 43 is reached figure 2 is reached. The cleaning solution can then be evenly distributed in the rotor chamber 9 by rotating the rotor, as explained above with reference to the first exemplary embodiment.

Furthermore, the second embodiment can be modified in that the hose 25 is formed into a siphon 41 ( Figure 4b ), i.e. the hose 25 is guided a little way up from the outlet opening 23 and then deflected downwards, so that liquid flowing into the hose 25 only overcomes the siphon if the liquid level in the rotor space 9 is the height of the reached siphons. With such an arrangement of the hose 25, either a suction pump 42 must be provided in the hose 25 in order to completely suck off the liquid from the rotor space 9 via the siphon 41 if necessary, or a lifting mechanism can be provided which lowers the hose 25 in such a way that the siphon 41 is lifted and the liquid contained in the tube 25 flows out solely by gravity.

Also in the second embodiment, non-foaming cleaning solutions or foaming cleaning solutions can be supplied. If foaming cleaning solutions are used, it is expedient, just as in the first exemplary embodiment, to supply a foam-reducing solution to the rotor space 9 in order to remove the foaming cleaning solution from the rotor space 9 .

The above exemplary embodiments and modifications show that the cleaning solution or the cleaning solutions can be supplied to or removed from the rotor space 9 in different ways in order to clean the rotor space 9 . What all exemplary embodiments and variants have in common is that the rotor 2 , which is inherently present in the centrifuge 1 , is used to distribute the cleaning solution evenly in the rotor chamber 9 . The rotational speed and the duration at which the rotor 2 is rotated is related to the geometry of the rotor interior 9 and adapt accordingly to the behavior of the cleaning solution. It can be particularly useful (regardless of the structural design of the centrifuge) to rotate the rotor 2 at least once clockwise and at least once counterclockwise in order to obtain a distribution of the cleaning solution in the rotor space 9 that is as uniform as possible. If one or more atomizing nozzles 40 are used, then it is expedient to supply the cleaning solution under pressure so that the atomizing nozzles 40 bring about efficient atomization of the cleaning solution.

The supply and even distribution as well as the removal of the cleaning solution from the rotor space 9 can be carried out fully automatically. As a result, the centrifuge 1 can be provided in an automatic production process in which many reaction vessel units 7 are repeatedly cleaned, it being ensured over the long term that no contamination from one reaction vessel unit 7 to another reaction vessel unit 7 occurs. The intervals between the cleaning processes of the rotor space 9 are to be adapted accordingly to the quantity and the reactivity of the reagents contained in the reaction vessel units 7 . Such a cleaning process can be carried out, for example, at an interval of no more than 10 minutes or no more than 60 minutes. In the case of less reactive reagents and small quantities, however, it can also be expedient to carry out such a cleaning process only once a day.

With the cleaning process, the interior can be completely disinfected and contamination, for example by viruses, bacteria or other infectious agents, can be reliably prevented.

Furthermore, in the case of samples containing DNA, agents can be used as solvents which destroy nucleic acids and thus rule out contamination. These agents are, for example, perchlorate, strong oxidizing agents and/or enzymes such as DNAses.

If an unforeseen contamination of the rotor space 9 takes place, for example if a reaction vessel unit 7 bursts during centrifuging, the system can be completely cleaned without the interior space or the device having to be opened.

The invention can be briefly summarized as follows:
The invention relates to a centrifuge 1 for cleaning a reaction vessel unit 7 and a method for cleaning such a centrifuge 1. The centrifuge 1 has a rotor 2 and a rotor space 9 in which the rotor 2 is arranged and rotatably mounted, the rotor 2 having a Receiving area 6 for receiving the reaction vessel unit 7 has. The rotor space 9 is delimited by a housing 3, the housing 3 having an outlet for draining liquid discharged from the reaction vessels and being provided with an inlet for filling the rotor space 9 with a cleaning solution in such a way that when the rotor 2 rotates, this is at least partially the cleaning solution is immersed and this is distributed in the rotor chamber 9 and/or the inlet is designed in such a way that the cleaning solution is distributed in the rotor chamber 9 when it is fed in by the rotating rotor 2 .

reference list

1

centrifuge

2

rotor

3

Housing

4

drive device

5

axis of rotation

6

recording area

7

reaction vessel unit

8th

Loading and unloading device

9

rotor space

10

lower shell

10a

lower shell

11

upper shell

11a

upper shell

12

front end wall

12a

front end wall

13

rear end wall

13a

rear end wall

14

ball-bearing

15

Wave

16

floor space

17

rotor chamber

18

balcony

19

ventilation opening

20

door

21

passage opening

22

gutter

23

exhaust port

24

connection spigot

25

Hose

26

funnel

27

funnel surface

28

vertical surface

29

level

30

dispensing unit

31

dispensing nozzle

32

reagent line

33

gutter

34

collection hose

35

branch

36

blocking element

37a

Side wall

37b

Side wall

38

direction of rotation

39

feed opening

40

atomizing nozzle

41

siphon

42

suction pump

43

level

Claims (13)

Centrifuge (1) for cleaning a reaction vessel unit (7) with a rotor (2) and a rotor chamber (9) in which the rotor (2) is arranged and rotatably mounted, the rotor (2) having a receiving area (6) for receiving the reaction vessel unit (7), and the rotor space (9) is delimited by a housing (3), the housing (3) having an outlet to drain liquid discharged from the reaction vessels and being provided with an inlet to supply the rotor space (9) with a cleaning solution in such a way that that the cleaning solution is distributed by turning the rotor (2) without reaction vessel units (7) in the rotor space (9) through contact with the rotor (2), so that the rotor space (9) is cleaned, wherein the axis of rotation (5) of the rotor (2) runs parallel to a base (16). Centrifuge (1) according to claim 1,
characterized,
that the outlet of the housing (3) also forms the inlet. Centrifuge (1) according to claim 2,
characterized,
that an opening in the housing (3), which forms the outlet and the inlet, is connected to a fluid line which has a branch and branches into an inlet line and an outlet line, the outlet line for discharging a fluid and the inlet line for supplying a fluid is formed, and the drain line has a blocking element (36) for blocking the drain line. Centrifuge (1) according to claim 3,
characterized,
that the feed line is fluidically coupled to a dispensing device integrated in the centrifuge (1), so that a cleaning solution can be fed to the feed line by means of the dispensing device. Centrifuge (1) according to one of Claims 1 to 4,
characterized,
that the flow has a suction pump and a siphon (41), wherein the siphon (41) so is designed so that when the suction pump is not actuated, a liquid with a fill level below a predetermined fill level remains in the rotor space (9). Centrifuge (1) according to one of Claims 1 to 5,
characterized,
that a level sensor for detecting the level in the rotor space (9) is provided. Centrifuge (1) according to one of Claims 1 to 6,
characterized,
that the inlet is arranged above an axis of rotation of the rotor (2), so that when the cleaning solution is fed in, it can come into contact with the rotor (2). Centrifuge (1) according to one of Claims 1 to 7,
characterized,
that the inlet has one or more nozzles in order to atomize the cleaning solution into the rotor space (9). Method for cleaning a centrifuge (1) for cleaning a reaction vessel unit (7), the centrifuge (1) having a rotor (2) and a rotor space (9) in which the rotor (2) is arranged and rotatably mounted, the The rotor (2) has a receiving area (6) for receiving the reaction vessel unit (7), the axis of rotation (5) of the rotor (2) running parallel to a standing surface (16), and the following steps being carried out: - the rotor space (9) is filled with a cleaning solution either at least up to a predetermined level (43), so that when the rotor (2) rotates, it is at least partially immersed in the cleaning solution, and/or the cleaning solution is added to the rotor space (9) supplied in such a way that it can either come into contact with the rotor (2) and/or is atomized into the rotor space (9), - the rotor (2) is rotated, whereby the cleaning solution is distributed in the rotor space (9), and - the cleaning solution is removed from the rotor chamber (9). Method according to claim 9,
characterized,
that the cleaning solution is a non-foaming cleaning solution containing, for example, formaldehyde or paraformaldehyde. Method according to claim 10,
characterized,
that the cleaning solution contains a foaming cleaning solution, in particular surfactants Is cleaning solution, and to remove the cleaning solution, a foam-degrading solution is supplied to the rotor space (9), which contains, for example, alcohol. Method according to claim 11,
characterized,
that during or after the supply of the defoaming solution, the rotor (2) is rotated to distribute the defoaming solution in the rotor space (9). Method according to one of claims 9 to 12,
characterized,
that a centrifuge (1) according to claims 1 to 8 is used.

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