Discharge device for a reaction vessel unit, centrifuge, and method for cleaning a reaction vessel unit
The drainage device addresses cross-contamination and wetting issues in centrifuge systems by using a drainage plate to channel liquid away from the rotor chamber, enhancing operational efficiency and reducing cleaning frequency.
Patent Information
- Application Number
- EP2023703204
- Authority / Receiving Office
- EP · EP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2022-02-04
- Filing Date
- 2023-02-02
- Publication Date
- 2025-10-22
- Estimated Expiration
- 2043-02-02
Abstract
Description
[0001] The present invention encompasses a drainage device for a reaction vessel unit, a centrifuge and a method for cleaning a reaction vessel unit.
[0002] It is known that reaction vessel units containing multiple reaction vessels, such as microtiter plates (MTPs) with their wells, are cleaned by centrifugation. The MTPs are placed on a rotor in a centrifuge's rotor chamber with the openings of the reaction vessels facing away from the rotor's rotational axis, and are centrifuged at a speed of up to several thousand rpm.
[0003] During centrifugation, the ejected contents of the reaction vessels are collected by a wall of the rotor chamber. Substances remaining on the walls and surfaces of the rotor chamber partially flow off and collect in the lower area, but can also drip from the top and enter an MTP located in the rotor chamber. If several MTPs are cleaned consecutively in the centrifuge, there is also a risk of cross-contamination, as centrifugate from one MTP drips into another MTP.
[0004] The rotation of the rotor creates air vortexes in every centrifuge. If liquid contents are ejected from the reaction vessels during rotation, these air vortexes cause the formation of aerosols. These also cause cross-contamination. In genomic applications (typically amplification-based, such as PCR), aerosols are therefore a driving force for contamination.
[0005] It has also been shown that centrifugally cleaned MTPs can still have wet surfaces even when the wells are completely emptied. This can complicate further use, for example, if the MTPs are subsequently sealed with a film. The film is typically applied to cover the openings of the wells. This can be used for sterile interim storage of the MTPs before further use or after filling with a test fluid to isolate the test regime. However, the wetted surface makes it difficult to seal the MTPs with a film.
[0006] DE 10 2017 113 583 A1 discloses a centrifuge in which the housing has a drainage channel below the rotor, and the inner surfaces of the housing adjacent to the channel form a funnel that opens into the channel. This allows the centrifugate accumulating in the rotor chamber to be collected and more effectively removed.
[0007] From DE 10 2021 124 023.9, which was still unpublished at the time of this application, it is known to supply a cleaning solution to the rotor chamber in such a way that the cleaning solution is distributed throughout the rotor chamber by rotating the rotor. Residues of the centrifugate can thus be removed from the walls and surfaces of the rotor chamber by regular, frequent rinsing with cleaning agents.
[0008] DE 20 2014 010 544 U1 discloses a centrifuge for cleaning a reaction vessel unit, in which a gap is provided between the inner surface and a rotor, so that a wind is generated by the rotation of the rotor, which drives the fluid ejected from the inner surface to a drain. The drain is connected to a suction pump for withdrawing the fluid.
[0009] For hygiene reasons, comparatively frequent cleaning cycles are required, resulting in downtime and high operating costs. This approach will be unavoidable, especially for diagnostic applications.
[0010] An object of the invention is to reduce or reliably prevent the risk of contamination of a reaction vessel unit in a centrifuge.
[0011] A further object of the invention is to minimize or reliably prevent the wetting of a reaction vessel unit in a centrifuge.
[0012] A further object of the invention is to minimize the residence time of aerosols in the centrifuge or to prevent the occurrence of aerosols.
[0013] A further object of the invention is to minimize the internal surfaces in the housing that can come into contact with the ejected liquid.
[0014] A further object of the invention is to minimize the volume of space into which liquid particles can penetrate.
[0015] A further object of the invention is to reduce or eliminate the effort required for cleaning the rotor chamber of a centrifuge for MTP.
[0016] A further object of the invention is to keep ejected fluid away from all elements of the device, such as the housing, the rotor and the rotor axis, so that these parts do not corrode or are exposed to other chemical interactions with the ejected fluid, in order to, among other things, minimize costs resulting from surface treatments of the elements of the device for chemical protection and to accelerate and simplify the manufacturing process.
[0017] One or more of the objects is achieved by the subject matter of the independent claims. Advantageous further developments are specified in the respective subclaims.
[0018] According to a first aspect of the invention, a drainage device for a reaction vessel unit comprising a plurality of reaction vessels, wherein the reaction vessels each have an opening lying in a common opening plane, is proposed. The drainage device comprises a drainage plate which is designed such that it can be arranged opposite the openings of the reaction vessels in a centrifuge and is designed such that it rotates with the reaction vessel unit during centrifugation and liquid emerging from the reaction vessels is collected and drained by the drainage plate due to the centrifugal acceleration. The drainage plate can be arranged obliquely with respect to the opening plane so that collected liquid is drained due to the centrifugal acceleration in the centrifuge along the obliquely arranged drainage plate in the axial direction of the rotation axis of the centrifuge rotor.The axial direction refers to the rotational axis of a centrifuge rotor. At least one discharge opening is formed on a front wall of the discharge device, toward which the discharge plate rises. The discharge opening has a spout that protrudes beyond the front wall.
[0019] In the context of the invention, a deflection plate is a structure having a surface opposite the opening plane of the reaction vessels. Liquid ejected from the reaction vessels by centrifugal acceleration can be collected on the surface and flow along under the effect of the centrifugal acceleration. In the simplest case, the deflection plate can be flat or essentially flat, arranged parallel to the opening plane, and open at the edge, particularly the flanks. The collecting surface is preferably connected in a rotationally fixed manner to the unit comprising the rotor and the reaction vessel unit and thus rotates at the same rotational speed as the rotor. The collecting surface can also rotate at a different rotational speed than the rotor.Since the flank-side edges of the discharge plate are radially furthest away from the axis of rotation, the collected liquid is driven from the center to the flank-side edges of the discharge plate due to centrifugal acceleration and from there thrown into the rotor chamber.
[0020] Ends of the rotor and thus also of the reaction vessel unit arranged thereon as well as the discharge device, which are opposite one another in the axial direction of the rotation axis, are referred to in the application as end faces or end face walls, while those ends of the rotor and of the reaction vessel unit arranged thereon as well as the discharge device, which are opposite one another transversely to the rotation axis, are referred to in the application as flank faces.
[0021] In modifications, the diverter plate can also be curved, kinked, or inclined, as long as the collected liquid is directed away from an area opposite the opening plane of the reaction vessels. The liquid discharged from the diverter device can be collected on the walls of the rotor chamber. Since the diverter plate is arranged opposite the openings of the reaction vessels, the diverter plate can also catch liquid dripping from a wall, in particular the upper wall, of the rotor chamber and prevent the reaction vessel unit from being contaminated by the liquid. Even if several reaction vessel units are cleaned one after the other, cross-contamination can be effectively and easily prevented. The diverter device can be reused after cleaning. The diverter device can be made of plastic or metal, for example.For cleaning, chemicals that decompose or inactivate organic molecules can be used, provided the material of the discharge device is resistant to the chemical. An autoclave can also be used for cleaning, provided the material of the discharge device is resistant to the temperatures involved.
[0022] In the context of the invention, inclined means that the height or distance of the discharge plate varies from the opening plane of the reaction vessels. The incline can be continuous or discontinuous (bent), constant (straight) or variable over its length (curved). It can run from one end face or end wall of the discharge device or reaction vessel unit to the other end face (one-sided) or from the middle to both end faces (both sides). Since the opening plane of the reaction vessels generally runs parallel to the axis of rotation when the reaction vessel unit is accommodated in the centrifuge, the incline also runs at an incline to the axis of rotation. Since the discharge plate is designed to be inclined in the axial direction relative to the opening plane or the axis of rotation, the collected liquid is drawn along the incline to one end face of the rotor or the centrifuge by centrifugal acceleration.The liquid is then driven into the rotor chamber, where it can be collected or ejected. The wall of the rotor chamber surrounding the rotor is less wetted, thus further reducing the risk of cross-contamination.
[0023] If the space above the reaction vessel unit within the drainage device is completely closed or only closed except for the drainage opening, the rotor chamber will not come into contact with liquid and contamination is therefore excluded.
[0024] It should be noted that drainage in the axial direction does not exclude a superimposed movement of the liquid perpendicular to the axis of rotation. In other words, the entire drainage movement of the liquid at the drainage plate represents a combination of the axial drainage with the drainage perpendicular to the axis. It can therefore be advantageous if flanks of the drainage device that run laterally along the axis of rotation are drawn downwards from the drainage plate in order to form an obstacle to movement of the liquid perpendicular to the axis of rotation. In this way, collection of the collected liquid at an axial end can be promoted by the liquid drained perpendicular to the axis also being drained axially on the downwardly drawn flanks. This can further improve the concentration of the liquids on an end wall.
[0025] In particular, flanks and end walls of the diverter device can be designed to be flush with an edge of the reaction vessel unit. In other words, if the reaction vessel unit with the diverter device is placed on the rotor of the centrifuge, the diverter device designed in this way can create a closed collecting space that is isolated from the rotor chamber. The rotor chamber is not or hardly wetted, therefore the effort required to clean the rotor chamber of a centrifuge for a reaction vessel unit can be reduced or minimized. Because the diverter device rotates with the rotor, the air in the rotor chamber is not or hardly swirled, therefore wetting of the surfaces of the reaction vessel units during centrifugation can be avoided. If swirling is low or prevented, aerosol formation in the collecting space is reduced or completely avoided.
[0026] The discharge opening is preferably flush or essentially flush with the inside of the discharge plate. Collected and discharged liquid is forced outwards and can be collected or further discharged at the front wall. Since the outer (flank) ends are located radially further out than the center of the front wall during centrifugation, the liquid will preferentially collect there, so that it can be best discharged there. It is therefore advantageous to provide two discharge openings, each at the outer (flank) end of the front wall. The discharge opening can be formed on the front side, i.e. axially, or on the flank side, i.e. perpendicular to the axis. An opening facing upwards is also conceivable in principle, although means would then have to be provided to prevent back-drip from above and to avoid contamination.
[0027] Such a spout moves in a circular path during centrifugation. Collected and discharged substance is expelled outward and can be discharged via the spout into an annular collecting channel in which the spout runs. Contamination of the rotor chamber can be even more effectively prevented, and cleaning effort can be further reduced. As previously mentioned, it is advantageous to provide two discharge openings, each with such a spout.
[0028] In some embodiments, the diverting device can be loosely attached to the reaction vessel unit, preferably in a form-fitting manner. The diverting device can be provided separately from the centrifuge. The reaction vessel unit can be prepared for centrifugation with the diverting device outside the centrifuge.
[0029] In further embodiments, the diverting device can be detachably connected to the reaction vessel unit. Here, too, the diverting device can be provided separately from the centrifuge. The reaction vessel unit can be prepared for centrifugation with the diverting device in a captive manner. The connection can be, for example, a clip connection, a plug connection, a snap connection, or a sliding connection.
[0030] In other embodiments, the discharge device can be detachably connected to a centrifuge rotor. This allows the rotor to be prepared to receive a reaction vessel unit. The discharge device can be removed for cleaning and is then ready for use again. The rotor can also be advantageously cleaned with the discharge device removed.
[0031] In further embodiments, the discharge device can be integrated with a centrifuge rotor. In this case, the rotor is ready to accommodate a reaction vessel unit without further preparation, simplifying laboratory work steps. The discharge device and / or the rotor chamber can be cleaned together or separately by rinsing the centrifuge or externally.
[0032] The discharge device can also be designed in several parts for easy removal and cleaning.
[0033] In yet further embodiments, the diverter device can be or can be connected to a rotor shaft of a centrifuge. The connection can be made, for example, by a cage or fork body or holding bracket that can be mounted or flanged into the centrifuge (on the rotor shaft) and which accommodates the diverter device, or the diverter device itself has a cantilever that can be mounted non-rotatably on the rotor shaft. Here, too, the rotor is ready to accommodate a reaction vessel unit without further preparation; handling the cover on the reaction vessel unit or on the rotor is not necessary. The rotor and diverter device can be cleaned separately. Work steps in the laboratory can be simplified. Cleaning can be done by rinsing in the centrifuge or (after disassembly from the rotor shaft) externally.
[0034] A further aspect of the invention relates to a centrifuge for cleaning a reaction vessel unit, comprising a drive and a rotor that can be coupled to the drive. The rotor is designed to accommodate a reaction vessel unit with a discharge device as described above. The centrifuge has the same advantages as the discharge device.
[0035] A collecting device may be provided, which is arranged in a rotor chamber of the centrifuge in which the rotor rotates and which is designed to collect liquid discharged by the discharge device. The collecting device can be designed depending on the type of liquid discharged by the discharge device. In particular, the collecting device can be designed to collect liquid that escapes from a discharge opening or spout of the discharge device during centrifugation.
[0036] For example, the collecting device can have an annular groove that is open to the rotor chamber and concentric with the rotation axis, which groove is located opposite a discharge opening of the discharge device. The groove can receive the collected and discharged substances from the discharge device without contaminating the rotor chamber. In particular, the groove can have an annular opening in which a spout of the discharge device, from which liquid emerges during centrifugation, can be accommodated. Even without a spout, the discharged substances can possibly reach the groove solely due to the velocity of the liquid and with suitable positioning.
[0037] The channel of the collecting device can be located axially opposite the discharge opening of the discharge device. This allows the channel to accommodate a spout that extends axially from the discharge device and rotates in a circular motion as the rotor rotates. The fluid can be collected even more cleanly and reliably. Because the channel accommodates the spout axially outside the end wall of the discharge device, fluid can flow from the channel onto the spout, but not onto any external surface of the discharge device.
[0038] The trough can have an annular opening formed axially toward the rotor chamber, with the annular opening having an undercut radially inward and / or radially outward. This allows liquids to be collected even more securely and flow freely and unhindered downwards in the trough, where they can be collected and, if necessary, drained or removed.
[0039] With an outlet device formed at a lower end of the collecting device, liquid can be drained directly from the collecting device to the outside.
[0040] A further aspect of the invention relates to a method for cleaning a reaction vessel unit having a plurality of reaction vessels, wherein the reaction vessels each have an opening lying in a common opening plane, wherein the reaction vessel unit is received on a rotor of the centrifuge with its openings pointing outwards from a rotation axis of the rotor, and the rotor with the reaction vessel unit arranged thereon is rotated in the centrifuge such that a liquid contained in the reaction vessels is spun out. Using a drainage device having a drainage plate, which is arranged radially outwards opposite the opening plane of the reaction vessels and rotates together with the reaction vessel unit, the spun out liquid is collected and drained along the drainage plate.The discharge device and / or the centrifuge is preferably designed according to the description of the above aspects of the invention. The method has essentially the same advantages and effects as the discharge device or centrifuge described above. The reaction vessel unit can be held on the rotor in a conventional manner using form-fitting elements, such as rail-like clamps, into which the reaction vessel unit is pushed. For this purpose, an end wall of the rotor chamber can have a loading window through which the reaction vessel unit can be pushed into and pulled out of the rotor chamber.The use of the diverter device and the execution of the method depend on the type of design and arrangement of the diverter device and can include a loose or fixed attachment of the diverter device to the reaction vessel unit before or after arranging the reaction vessel unit on the rotor, a detachable or non-detachable attachment of the diverter device to the rotor before or (only in the case of a detachable attachment) after arranging the reaction vessel unit on the rotor, and an attachment of the diverter device to a rotor shaft of the drive separately or together with the rotor. For example, a diverter device can be provided permanently on the rotor of the centrifuge. In this case, the reaction vessel unit is simply placed in the centrifuge on the rotor under the diverter plate of the diverter device.In other cases, the diverter device may form an assembly with the reaction vessel unit, which is assembled outside the centrifuge and is loaded into and unloaded from the centrifuge together.
[0041] The drainage device can be cleaned after one or more centrifugation processes. Cleaning can be carried out by autoclaving and / or chemical agents and / or irradiation. Cleaning the drainage device is simpler and more cost-effective than cleaning the entire centrifuge or the entire rotor chamber with rotor. Because the drainage device is provided, cleaning intervals for the centrifuge itself or the rotor chamber can be extended, particularly if the drainage device forms a closed collecting space from which little or no liquid enters the rotor chamber itself. A collecting device provided within the rotor chamber of the centrifuge for collecting liquid drained from the drainage device can be cleaned together with the drainage device or separately using the same or a different method.A particularly simple way to clean the drainage device is to centrifuge a reaction vessel unit filled with a cleaning solution. The collection device can also be cleaned using the cleaning solution emerging from the drainage device.
[0042] A centrifuge rotor chamber can be cleaned after a predetermined number of centrifugation cycles. Cleaning can be performed by rinsing with a rinsing solution or by separately cleaning disassembled parts of the centrifuge that border the rotor chamber. Examples of suitable cleaning methods include autoclaving, chemical agents (biocides), or irradiation. Because the drainage device is provided, the predetermined number of centrifugation cycles after which cleaning can be carried out can be greater, thus extending the cleaning intervals of the centrifuge or rotor chamber. A collecting device provided within the rotor chamber for collecting liquid drained from the drainage device can be cleaned in the same operation or separately using a different method. Here, too, it is possible to clean the rotor chamber by centrifuging a reaction vessel unit filled with a cleaning solution.This process is particularly easy to carry out if the drain device is open at the sides, as this allows the cleaning solution to easily enter the rotor chamber. If the drain device is closed, the drain device can be removed from the rotor before the cleaning cycle with cleaning solution, allowing the cleaning solution to reach the inner walls of the rotor chamber. If the rotor has two locations for reaction vessel units, but only one of the locations is equipped with a drain device that forms a closed collecting space, the reaction vessel units can be placed on the location with the drain device to clean the reaction vessel units, while the reaction vessel unit with the cleaning solution can be placed on the location without the drain device to clean the rotor chamber.For cleaning the collecting device in the rotor chamber, a cleaning solution can be dispensed with if the rotor or the discharge device is aerodynamically designed in such a way that the collecting device (for example a channel as described above) is cleaned (blown out) by an air flow generated during rotation.
[0043] Selected embodiments of the present invention are described in detail below with reference to the accompanying drawings. They show: Figure 1A shows a centrifuge in a side view from the outside; Figure 1B shows the centrifuge from Figure 1A in a frontal view in the direction of an arrow "B" in Figure 1A ; Figure 2 an interior of a rotor box of the centrifuge of Figures 1A, 1B with a reaction vessel unit without discharge device in a frontal view with the end wall removed; Figure 3 the interior of the rotor box of Figure 2with a reaction vessel unit and with a discharge device according to the invention in a frontal sectional view corresponding to a Figure 1A by a line "III" indicated cutting plane; Figure 4A the centrifuge in a side view according to Figure 1A with the hood removed; Figure 4B the centrifuge of Figure 4A in a frontal view in the direction of an arrow "B" in Figure 4A ; Figure 4C the centrifuge of Figure 4A with the hood removed, with a rotor box and elements therein arranged along a plane "C" in Figure 4B are cut; Figure 4Dthe rotor box of the centrifuge from Figure 4A in an enlarged view corresponding to a section "D" in Figure 4C ; Figure 4Eden rotor box of the Figure 4A in a side view cut along a plane "E" in Figure 4B ; Figures 4F,4G,4H the centrifuge of Figure 4A in a frontal view in the direction of an arrow "F", "G" and "H" in Figure 4A; Figure 5Athe rotor box of the centrifuge from Figure 4A in a perspective view; Figure 5B the rotor box from Figure 5A in a perspective view cut along the plane "E" in Figure 4B ; Figure 6A an assembly with rotor shaft, rotor, discharge device and collecting device in the centrifuge with reaction vessel unit accommodated therein in a perspective view; Figure 6B the assembly of Figure 6A in another perspective view; Figure 6C the assembly of Figure 6A cut along the plane "C" in Figure 4B ; Figure 7A an assembly with rotor shaft, rotor and discharge device in the centrifuge with reaction vessel unit accommodated therein in a perspective view; Figure 7B the assembly of Figure 7A cut along the plane "C" in Figure 4B; Figure 8 Variants (a) to (g) of a contour of the discharge plate with reaction vessel unit on a rotor in cross-section transversely or perpendicularly to the rotation axis; Figure 9 Variants (a) to (h) of a contour of the discharge plate with reaction vessel unit on a rotor in an axial section along the rotation axis.
[0044] All drawings are schematic. Proportions may be distorted for clarity. Directional and positional designations refer, unless otherwise stated, to the usual use of the subject matter of the invention.
[0045] A centrifuge 1 has a drive box 2 and a rotor box 3, which rest on feet 4 ( Figures 1A, 1B). The drive box 2 houses a drive unit, such as an electric motor (not shown in detail). The drive box 2 has a cover 5, which is fastened to a supporting structure of the rotor box 3 by means of screws 6. The supporting structure can be supported by an end wall 7 as well as by a base 27 and a rear wall 28 of the rotor box 3 (see, for example, Figure 5A with screw holes 53 for mounting the hood 5). The hood 5 can have two side walls 13 and an upper wall 14, which are formed as individual elements or as a continuous angled sheet metal structure (cf. Figure 2 ). The side walls 13 and the upper wall 14 of the hood 5 as well as the end wall 7, a base 27 and a rear wall 28 of the rotor box 3 define or encompass an interior of the rotor box 3, which is also referred to as a rotor chamber 29. The end wall 7 has a loading window 8 (cf. Figure 1B), through which an interior of the rotor box 3 is accessible in order to connect the centrifuge with a reaction vessel unit 21 ( Figure 2 ) as is known per se. The end wall 7 can also have an axle opening 9 ( Figure 1B ), which accommodates a rotor shaft 10 of the centrifuge 1 for rotation about a rotation axis 11. The axis opening 9 can also be designed as a bearing seat for a bearing 12 for supporting the rotor shaft, but the rotor shaft can also run freely in the axis opening 9.
[0046] The rotor shaft 10 carries a rotor 20 which is connected to the rotor shaft 10 in a rotationally fixed manner in order to rotate in an interior of the rotor box 3 ( Figure 2). For this purpose, the rotor shaft 10 is connected to an output shaft of the drive unit of the centrifuge 1. Alternatively, it is also conceivable for the rotor shaft 10 to be an integral part of the output shaft of the drive unit. The rotor 20 is designed to accommodate at least one reaction vessel unit 21; in the present exemplary embodiment, the rotor 20 can accommodate two reaction vessel units 21, of which only one is shown in the figure. The rotor 20 has a frame 22 which is approximately cuboid-shaped and is or can be connected in a rotationally fixed manner to the rotor shaft 10. On two axially opposite sides of the frame 22, a receiving space 23 for a reaction vessel unit 21 is formed. In variant designs, only a single receiving space 23 or more than two receiving spaces 23 can be provided. The receiving space 23 is delimited by two rail-like clamps 24 which protrude from the frame 22.A support surface 25 for the reaction vessel unit 21 is formed on the frame 22 itself, while respective counter surfaces 26 are formed on the clamps 24, which are formed parallel to the support surface 25 and are spaced from it to fit according to a height of the reaction vessel unit 21. The reaction vessel unit 21 can be placed on the rotor 20 in a conventional manner via the loading window 8 in the end wall 7 or removed from it when the rotor 20 is in a position in which the receiving space 23 is exactly opposite the loading window 8. The loading process can be carried out automatically by means of a loading device, as known from WO 2017 / 125598 A1. For this purpose, the loading device has an automatically actuable displacement rod (not shown) for positioning a reaction vessel unit.
[0047] The reaction vessel unit 21 is a body with a plurality of individual reaction vessels 37, which are arranged next to one another in the reaction vessel unit 21 and each have an opening 38 on one side ( Figure 3). The openings 38 lie in a common opening plane 39 and point radially outwards for cleaning purposes. The clamps 24 of the receiving locations 23 are designed such that they only grip the reaction vessel unit 21 at the edge, so that the openings 38 of the individual reaction vessels 37 of the reaction vessel unit 21 are exposed. When the rotor 20 rotates at a suitable rotational speed about the rotation axis 11, liquids contained in the reaction vessels 37 of the reaction vessel unit 21 can be centrifuged radially outwards. The liquid centrifuged out of the reaction vessel unit 21 can be caught by the walls of the rotor chamber 29, in particular the inner sides of the side walls 13 and the upper wall 14 of the hood 5 as well as an upper width of the base 27, from there drain downwards and, if necessary, be caught and discharged, as is known per se. The rotational speed for this purpose is several hundred to several thousand rpm.
[0048] According to an embodiment of the present invention, a discharge device 30 is provided which is arranged radially outside the reaction vessel unit 21 ( Figure 3). The diverting device 30 has a diverting plate 31 which is arranged opposite the openings 38 of the reaction vessels 37. The diverting plate 31 extends both in the width direction w and in the axial direction (direction of the rotation axis 11) beyond the dimensions of the rotor 20. In modifications, it may be sufficient if the diverting plate 31 covers at least the reaction vessel unit 21 or at least all of the openings 38 of the reaction vessels 37 of the reaction vessel unit 21. When the rotor 20 rotates at a rotational speed suitable for centrifugation, liquid from the reaction vessels 37 is thrown through the openings 38 by the effect of centrifugal force and intercepted by the diverting plate 31.In the region of a center plane 36, which runs perpendicularly through the opening plane 39 of the reaction vessel unit 21 and along the rotation axis 11, a radial distance r 0 of the discharge plate 31 from the rotation axis 11 is smallest, while the radial distance r in the width direction r increases toward the edge 32 of the discharge device. Accordingly, a centrifugal acceleration toward the edge 32 of the discharge device 30 also increases, so that the collected liquid is driven along a surface of the discharge plate 31 in the width direction w toward the edge 32. A flank 33 of the discharge device 30 adjacent to the edge 32 of the discharge plate 31 can be open, so that the outwardly driven liquid is driven further beyond the edge 32 by the centrifugal acceleration and ejected into the rotor chamber 29.When the rotor 20 remains in the position in which the reaction vessel unit 21 can be removed via the loading window 8 of the front wall 7, the diverter device 32 prevents liquid dripping from the upper wall 14 from flowing back into the reaction vessels 37, so that the reaction vessel unit 21 can be removed cleanly. This effectively prevents cross-contamination when centrifuging multiple reaction vessel units 21 with different contents.
[0049] If the edge 32 of the discharge plate 31 is arranged offset laterally from the reaction vessel unit 21 on the one hand and is drawn downwards, ie towards the rotor, on the other hand, a drip edge can also be formed from which liquid can drip down next to the rotor 20 when the rotor 20 is at a standstill.
[0050] The edge 32 of the deflection plate 31 can also be pulled down so far that it retains the liquid ejected from the reaction vessel unit 21 during rotation, and this liquid only drips down the side of the rotor 20 when the rotor is stationary. This can also significantly reduce wetting of the inner walls of the rotor chamber 29.
[0051] The diverter device 30 can be formed integrally with the rotor 20 or can be attached or attachable to it. The diverter device 30 can, in particular, be removable from the rotor 20 so that it can be cleaned separately. The diverter device 30 can also be attached to the rotor shaft 10 independently of the rotor 20 (not shown in detail).
[0052] In a further embodiment, the discharge plate 31 of the discharge device 30 is designed to rise from a front end wall 41 to an opposite rear end wall 42 of the discharge device 30 ( Figures 4A to 7B ). This embodiment is a preferred modification of the embodiment of Figure 3and makes use of its features unless otherwise described below. The front end wall 41 is located on the side of the end wall 7 of the rotor box 3, viewed in the axial direction, and the rear end wall 42 of the deflection device 30 is located on the side of the rear wall 28 of the rotor box 3, viewed in the axial direction. In other words, the deflection plate 31 has a slope which, with respect to the rotational axis 11 of the rotor 20, is designed to rise towards the rear end wall 42 of the deflection device 30 and thus towards the rear wall 28 of the rotor box 3. An inner side of the deflection plate 31 forms a deflection angle α with the rotational axis 11 of the rotor 20 or with the opening plane 39 of a reaction vessel unit 21 accommodated on the rotor 20 ( Figures 4A , 4C). During the centrifugation process at a rotational speed, liquid trapped on the discharge plate 31 is consequently drawn along the slope (arrow direction a in Figure 4C ) to the rear end wall 42 of the discharge device 30. Two drain openings 43 are formed in the rear end wall 42, each of which is connected to a spout 44 projecting from the rear end wall 42 in the axial direction.
[0053] On the rear wall 28 of the rotor box 3, which adjoins the drive box 2, a deflection device 40 is provided. The deflection device 40 can be formed integrally with the rear wall 28 or manufactured separately and connected to the rear wall 28. (It should be noted that the collecting device is also shown schematically in Figures 2 and 3is shown, but is not functionally required there.) In the present embodiment, the collecting device 40 is a ring- or disc-shaped structure that is arranged on an inner side of the rear wall 28. However, the invention is not limited to this shape, and the collecting device 40 can, in principle, have any desired shape that is suitable for collecting and draining the liquid.
[0054] On the side facing the rotor 20, i.e., the inside, an annular groove 45 is formed in the collecting device 40. The groove 45 has an annular opening 46 pointing in the axial direction toward the rotor chamber 29. Behind the annular opening 46, the groove 45 widens radially inward and radially outward to form an inner undercut 47 and an outer undercut 48 with the annular opening 46. At the lowest point, the collecting device 40 has a drainage device 49, which is connected to the groove 45. The two nozzles 44 of the discharge device 30 protrude through the annular opening 46 into the groove 45. The liquid collected by the discharge device 30 on the discharge plate 31 collects under the effect of centrifugal acceleration at the outer (flank-side) ends of the rear end wall 42 of the discharge device 31 in the width direction.From there, it flows through the drain openings 43 into the spouts 44 and is discharged from there into the channel 45. In the channel 45, the liquid can flow downwards and be removed from the rotor chamber 29 through the drain pipe 49.
[0055] Since all of the liquid ejected from the reaction vessel unit 21 is collected in the channel 45, the interior of the rotor box 3 (the rotor chamber 29) remains largely unwetted by the liquid. Only mist resulting from turbulence can pass from the channel 45 into the rotor chamber 29 and wet its walls.
[0056] In a preferred embodiment, the discharge device 31 is designed such that it is flush with the lateral edges of the reaction vessel unit 21 and / or the rotor with flanks 33 or lateral walls, thus forming a substantially enclosed space. As a result, the atmosphere within the discharge device 31 is entrained as the rotor rotates and is not, or only slightly, disturbed. This prevents the formation of aerosols that spread throughout the rotor chamber 29.
[0057] Only if the formation of such a contaminated mist cannot be prevented is periodic cleaning of the interior of the rotor box 3 necessary. The cleaning intervals can generally be extended considerably compared to a centrifugation process without the diverter device 30 and collecting device 40. The diverter plate 31 reliably protects the reaction vessel unit 21 from any contamination caused by liquid that may drip from the upper wall 14 of the hood 5.Since the diverting device 30 is also closed at the flanks 33, the diverting device 30 forms a sealed space with the reaction vessel unit 21, so that any liquid mist that may be present in the rotor chamber 29 cannot settle on a surface of the reaction vessel unit 21, and turbulence due to rotation in the space between the reaction vessel unit 21 and the diverting plate 31 can be effectively prevented. The reaction vessel unit 21 can therefore be reliably and completely cleaned by centrifugation with the diverting device 30 of this exemplary embodiment and protected from any wetting by the centrifugation process or contamination by falling drops.
[0058] The invention has been described above using preferred embodiments. It is understood that numerous modifications are possible within the scope of the invention. The shape of the deflection plate 31 depends on the desired effects. Figure 8 schematically shows several variants 8(a) to 8(g) of a contour of the discharge plate 31 with reaction vessel unit 21 in a cross section (radial section) perpendicular or radial to the rotation axis 11. Figure 9 shows schematically several variants 9(a) to 9(h) of a contour of the discharge plate 31 with reaction vessel unit 21 in an axial section along the rotation axis 11. It is understood that further variants are conceivable. The cross-sectional shapes of the Figures 8 and 9 can be combined in any way. They can be designed with open or closed flanks.
[0059] The deflection plate 31 can be perpendicular to the rotation axis ( Figure 8 ) even ( Figure 8(a)), with a central bend 80 along the rotation axis ( Figures 8(b), (e) ), with two lateral kinks along the rotation axis ( Figures 8 (d, g) or curved (c, f), concave when viewed from the outside ( Figures 8(b), (c), (d) ) or convex ( Figures 8(e), (f), (g) ) have been trained. As in connection with Figure 2 As described, the centrifugal acceleration in the cross-sectional plane transverse to the rotation axis 11 always acts in the direction of the larger radius r, therefore liquid collected on the inside of the discharge plate 31 is also drawn into the discharge plate 31 when the discharge plate is flat ( Figure 8(a) ) to the flank-side edges 32. This effect can be enhanced by a concave design in which the edges 32 are pulled away (upwards) from the rotation axis ( Figures 8(b), (c), (d) ), by a convex design in which the edges 32 are drawn towards the axis of rotation (downwards), but are weakened ( Figures 8(b), (c), (d) ). For a convex shape with a central bend 80 ( Figure 8(e)), the discharge plate initially drops more steeply than a circumference 82 around the rotation axis. Therefore, fluid can accumulate in the area around the central bend 80 up to a reversal point 83, from which the discharge plate 31 drops more gently than the circumference 82. To avoid this, the shape with two lateral bends 81, which are arranged beyond the reversal point 83, is preferable, since then the fluid is reliably drained outwards from the central area ( Figure 8(g) ). For the same reason, it is advantageous if the curvature of a deflection plate 31 with a convex cross-section ( Figure 8(f) ) the radius of curvature of the deflection plate 31 is greater than the radial distance of the deflection plate 31 at the point closest to the axis, i.e. in the area of the center plane 36.
[0060] In an axial section along the rotation axis ( Figure 9 ) the deflection plate 31 can be flat, i.e. at the same distance from the rotation axis 11 ( Figure 9(a)), sloping on one side, thus rising from a first end wall 41 to a second end wall 42 ( Figures 9(b)-(d) ), sloping on both sides, thus rising towards both end walls 41, 42 ( Figures 9(e)-(g) ) or descending ( Figure 9(h) ), whereby the slope is straight ( Figures 9(b), (e), (h) ) or arched ( Figures 9(c), (d), (f), (g) ), concave when viewed from the outside ( Figures 9(d), (e), (f) ) or convex ( Figures 9(c), (g)), and wherein the shapes which are inclined on both sides can have a kink 91 between the end walls 41, 42. Due to the axial inclination, which increases towards one or both end walls 41, 42, liquid is diverted due to centrifugal acceleration along the inside or underside of the diverter plate 31 to the respective end wall 41, 42 towards which the inclination increases. The flow velocity can be slowed down towards the respective end wall by a convex shape or accelerated by a concave shape. In the case of axially inclined shapes, it is useful if the flanks are closed or at least drawn down far enough to create an obstacle to the flow transverse to the axis of rotation, so that the liquid is only diverted to the end wall(s) towards which the inclination increases, where the liquid can be collected without wetting the rotor chamber.With a one-sided slope, the construction effort for collecting the liquid is lower, since a collecting device for the drained liquid only needs to be provided on one side. This is preferably provided on a rear wall of the rotor chamber, as the liquid can then be reliably drained away from the front wall from which the reaction vessel unit is loaded. If very large quantities of liquid are to be drained, a two-sided slope can be advantageous, as the liquid can then be collected more quickly. A two-sided contour of the drain plate 31, rising from the front walls 41, 42 to a cross-section 90, can concentrate the liquid in a kink 91 on the two flank edges. There, the liquid can be ejected laterally through the respective drainage openings.If necessary, a channel-like annular collecting device can be provided in the rotor chamber in the region of the cross section 90, which collects the liquid ejected there and drains it downwards.
[0061] Further variants are conceivable. For example, the drainage device 30 can have a trough shape without further drainage openings. In this variant, it is advantageous if the drainage device 30 is mounted outside the centrifuge 1 on the reaction vessel unit 21 and the reaction vessel unit 21 is loaded into the centrifuge in this way. In this case, the method is to be modified such that the rotor remains in the lower position at the end of the centrifugation process, so that the drainage device 30 comes to lie below the reaction vessel unit 21, and the reaction vessel unit 21 with the drainage device 30 and the liquid collected therein is unloaded through a unloading window (not shown in detail) in the end wall 7 and separated from the drainage device 30. The drainage device 30 is then freed of the liquid, cleaned, and prepared for another centrifugation process.With this variant, the rotor chamber remains free of the ejected liquid even without a collecting device installed. No drainage device is required on the rotor, and cleaning the rotor chamber and the drainage device can be made even easier.
[0062] It should be noted that the Figure 2 shown embodiment corresponds to a combination of the cross-sectional shape 8(a) with the axial section shape 9(a) with open flanks and the embodiment shown in Figures 3A to 7B corresponds to a combination of the cross-sectional shape 8(a) with the axial section shape 9(b) with closed flanks.
[0063] With the drainage device of the present invention, the centrifuge according to the invention, and the associated method, cross-contamination between reaction vessel units can be prevented, depending on the design of the drainage device, wetting of the reaction vessel units by aerosols in the rotor chamber can be reduced or completely avoided, and contamination of the rotor chamber by ejected liquid can be significantly reduced or completely avoided. The latter can considerably simplify cleaning of the rotor chamber. If the liquids are completely collected in the channel 45 of the collecting device 40 and leakage into the rotor chamber is prevented, a closed rotor chamber may be dispensed with. In other words, the end wall 7 and the hood 5, and possibly also the base 27 (unless the latter is required for stability reasons) of the rotor box 3, can be omitted.This can significantly simplify the loading and unloading process of the rotor 20. List of reference symbols 1 centrifuge 38 opening 2 Drive box 39 Opening level 3 rotor box 40 Catching device 4 Foot 41 front (first) end wall 5 hood 42 rear (second) end wall 6 screw 43 Discharge opening 7 front wall 44 spout 8 Loading window 45 gutter 9 Axle opening 46 Ring opening 10 rotor shaft 47 inner undercut 11 axis of rotation 48 external undercut 12 warehouse 49 drainpipe 13 side wall 50 plate 14 upper wall 51 Frame 20 rotor 60 module 21 Reaction vessel unit 70 module 22 Frame 80 central kink 23 Recording location 81 lateral bend 24 bracket 82 radius 25 Support surface 83 turning point 26 Counter surface 84 Surface normal 27 base 90 Central cross-section 28 back wall 91 kink 29 rotor chamber 30 discharge device a Discharge direction 31 discharge plate r radius 32 edge r 0 smallest radius 33 flank w Latitude direction 35 edge 36 Middle level α deflection angle 37 reaction vessel
[0064] This list is an integral part of the description.
Claims
1. A discharge device (30) for a reaction vessel unit (21) comprising a plurality of reaction vessels (37), the reaction vessels (37) each having an opening (38) lying in a common opening plane (39), the discharge device (30) comprising a discharge plate (31) which is designed such that it can be arranged in a centrifuge (1) so as to be opposite the openings (38) of the reaction vessels (37) and is designed such that it rotates together with the reaction vessel unit (21) during centrifugation and any liquid escaping from the reaction vessels (37) due to centrifugal acceleration is collected by and discharged from the discharge plate (31), the discharge plate (31) being able to be arranged obliquely with respect to the opening plane (39) in axial direction of a rotational axis (11) of a rotor (20) of the centrifuge (1) so that collected liquid is discharged along the obliquely arranged discharge plate (31) in the axial direction of the rotational axis (11) of the rotor (20) of the centrifuge (1) due to centrifugal acceleration in the centrifuge (1), at least one outlet opening (43) being formed on an end face wall (42) of the discharge device (30), toward which the discharge plate (31) rises, the outlet opening (43) comprising a spout (44) that protrudes beyond the end face wall (42).
2. The discharge device (30) according to claim 1, wherein flanks (33) of the discharge device (30) which run laterally along the rotational axis (11) are extended downwards starting from the discharge plate (31) to form an obstacle to movement of the liquid transverse to the rotational axis (11).
3. The discharge device (30) according to claim 2, wherein the flanks (33) and the end face walls (41, 42) of the discharge device (30) are formed so as to close off with an edge (35) of the reaction vessel unit (21).
4. The discharge device (30) according to any one of claims 1 to 3, wherein the at least one outlet opening (43) is flush or substantially flush with the inner side of the discharge plate (31).
5. The discharge device (30) according to any one of the preceding claims, wherein the discharge device (30) can be loosely placed on the reaction vessel unit (21), preferably in a form-fitting manner.
6. The discharge device (30) according to any one of claims 1 to 5, wherein the discharge device (30) can be connected to the reaction vessel unit (21) in a detachable manner.
7. The discharge device (30) according to any one of claims 1 to 5, wherein the discharge device (30) can be connected to a rotor (20) of a centrifuge (1) in a detachable manner.
8. The discharge device (30) according to any one of claims 1 to 5, wherein the discharge device (30) is integrally formed with a rotor (20) of the centrifuge (1).
9. The discharge device (30) according to any one of claims 1 to 5, wherein the discharge device (30) is connected or connectable to a rotor shaft (10) of a centrifuge (1).
10. A centrifuge (1) for cleaning a reaction vessel unit (21), comprising a drive, a rotor (20) that can be coupled or is coupled to the drive, wherein the rotor (20) is designed to accommodate a reaction vessel unit (21) having a discharge device (30) according to any one of the preceding claims.
11. The centrifuge (1) according to claim 10, wherein a collection device is provided which is arranged in a rotor chamber of the centrifuge (1) in which the rotor (20) rotates and which is designed to collect any liquid discharged by the discharge device (30).
12. The centrifuge (1) according to claim 11, wherein the collection device comprises an annular channel (45) which is open toward the rotor chamber and concentric with the rotational axis (11) and which is opposite a outlet opening (43) of the discharge device (30).
13. The centrifuge (1) according to claim 12, wherein the channel (45) is opposite the outlet opening (43) of the discharge device (30) in the axial direction.
14. The centrifuge (1) according to claim 12 or 13, wherein the channel (45) comprises an annular opening (46) formed axially toward the rotor chamber, the annular opening (46) comprising an undercut (47, 48) radially inward and / or radially outward.
15. The centrifuge (1) according to any one of claims 11 to 14, wherein a draining device (49) is formed at a lower end of the collection device (40).
16. A method of cleaning a reaction vessel unit (21) comprising a plurality of reaction vessels (37), the reaction vessels (37) each comprising an opening (38) lying in a common opening plane (39), wherein the reaction vessel unit (21) is accommodated on a rotor (20) of the centrifuge (1) with its openings (38) pointing outward from a rotational axis (11) of the rotor (20); and the rotor (20) together with the reaction vessel unit (21) arranged thereon is rotated in the centrifuge (1) so that a liquid contained in the reaction vessels (37) is ejected, characterized in that a discharge device (30) having a discharge plate (31), which is arranged radially outside opposite the opening plane (39) of the reaction vessels (37) and rotates together with the reaction vessel unit (21), collects the ejected liquid and discharges it along the discharge plate (31), wherein the discharge device (30) is designed according to any one of claims 1 to 9, and / or wherein the centrifuge (1) is designed according to any one of claims 10 to 15.
17. The method according to claim 16, wherein the discharge device (30) is cleaned after one or more centrifugation processes, wherein the cleaning is preferably carried out by rinsing with a rinsing solution contained in a reaction vessel unit (21) or by autoclaving and / or by chemical means and / or by irradiation.
18. The method according to claim 16 or 17, wherein a rotor chamber (29) of the centrifuge (1) is cleaned after a predetermined number of centrifugation processes, wherein the cleaning is preferably carried out by rinsing with a rinsing solution contained in a reaction vessel unit (21) or by separate cleaning of dismantled parts of the centrifuge (1) which delimit the rotor chamber (29), preferably by autoclaving and / or by chemical means and / or by irradiation.
Citation Information
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