WO1998007507A1

WO1998007507A1 - Process and device for the mixing or separation of substances of varying mass and/or density

Info

Publication number: WO1998007507A1
Application number: PCT/DE1997/001776
Authority: WO
Inventors: Norbert Krämer
Original assignee: Kraemer Norbert
Priority date: 1996-08-16
Filing date: 1997-08-18
Publication date: 1998-02-26
Also published as: EP0921852B1; DE59703920D1; AU4009197A; DE19632875A1; EP0921852A1; ATE202497T1; DE19780861D2

Abstract

The invention relates to a process and a device for the mixing/separation of substances of varying mass and/or density in at least one container (7, 7', 7'', 7''''), which is held in a holding device which is moved by a driving unit (12) and drives the container (7, 7', 7'', 7''''). The container (7, 7', 7'', 7'''') or the holding device is moved substantially backwards and forwards in a tangent along a cyclically passed-through, open or closed movement path with at least two areas of substantial modification of path curvature or at least two cuspidal points with high path acceleration by the driving unit (12), excluding rotation of the container (7, 7', 7'', 7'''').

Description

Method and device for mixing or separating substances of different mass and / or density

Technical field:

The invention relates to a method and a device for mixing / separating substances of different mass and / or density located in at least one container, which is held in a holder which is moved by a drive unit while taking the container with it, according to the preambles of claims 1 and 4th

State of the art:

For all kinds of tests in all kinds of laboratories, samples must be examined that consist of liquids that contain particles of different weights. Often, particles of different weights have to be intimately mixed with one another or mixed particles also separated, for which purpose these samples are filled into containers and stirred or whisked or shaken according to the known state of the art, or, if desired, the samples are centrifuged by rapid movement on a circular path be centrifuged. With separation, the heavier components move outwards and the lighter components remain closer to the center of the circular movement. However, it is known that a long period of constant force on the samples, as is the case with centrifugation, is disadvantageous for a number of substances.

DE-2354368-A1 discloses a device for the centrifugal separation of a liquid in fractions of different densities, which has a separation container which is attached to a centrifuge motor and is moved by it on an orbit about a first axis. A housing enclosing the separation container is arranged rotatably about a second axis, so that both rotary movements overlap with respect to the separation container. Each point of the separation container always remains the same distance from the first axis.

DE-1432853-A1 discloses a method and a device for separating substances by gyrofugation, in which a closed container rotates about two different axes. A centrifuge for separating and regrouping particles has become known from US Pat. No. 2,222,266-A. The centrifuge has several drivable axes around which the particles to be centrifuged can rotate simultaneously, so that the particles pass through a superimposed, composite path curve.

Technical task:

The present invention has for its object to provide a method and an apparatus for mixing or separation of substances to be mixed or separated according to the type mentioned, which allow improved mixing or separation of components that are otherwise difficult to are mixed or have only a slight difference in specific weight when separated, the method and the device being intended to permit improved sample treatment for many applications.

Disclosure of the invention and its advantages:

This object is achieved according to the invention in a method for mixing, separating substances of different mass and / or density in at least one container, which is held in a holder which is moved by a drive unit while driving the container, in that the container or the holder moves substantially tangentially back and forth along a cyclically traversed open or closed movement path with at least two areas of strong change in path curvature or at least two reversal points with large path acceleration taking place in these areas or reversal points, with the exception of rotation of the container becomes. A device for carrying out the method is characterized in that the container or the holder by means of the drive unit along a cyclically traversed open or closed movement path with at least two areas of strong change in path curvature or at least two reversal points with a large path taking place in these areas or reversal points - Acceleration, excluding rotation of the container, is guided substantially tangentially back and forth.

In an advantageous manner, the invention makes use of the effect that the acceleration forces acting on the particles become very large in reversal points or in parts of strongly changing path curvatures and even go towards infinity for a reversal of movement by 180 degrees, if only - - The time for the reversal of movement is made sufficiently short. Therefore, in the method according to the invention and when using the device even with very poorly mixing substances or with the separation of mixed substances even with small differences in mass and or density, an optimal mixing or separation is guaranteed.

The method and the device according to the invention are particularly suitable for mixing substances of different masses and or densities that are difficult to mix.

In addition, the invention is also suitable for separating substances by mass and / or density, in which case a brief force to separate particles, interrupted by phases without significant force, as made possible by the device according to the invention, none or practically none negative influences, but in many cases can have an advantageous effect on the samples with regard to further analysis or post-treatment.

In a further embodiment of the method, the container is elongated in the form of a sample glass and extends in its longitudinal extent in the direction of the movement path on the holder, the sample glass essentially tangentially on an open movement path along part of a circular arc with a predetermined radius (r) and is moved back and forth with two reversal points or along a straight line with two reversal points in the ends of the movement path. A particularly simple coupling to the drive unit is possible, which, in the case of a conventional design, preferably causes a rotary movement, for example as an electric motor.

The container can also along an ellipse or along an "oo" with two areas of strong change in path curvature on a closed trajectory or along a semi-ellipse with a region of strong curvature change and two reversal points on an open trajectory and each with a predetermined radius (r) on one Ball socket can be moved essentially tangentially back and forth. The long axis to short axis ratio is preferably a large number. Likewise, the holder can be guided along a semi-ellipse with a region of strong change in path curvature and two reversal points. In a further embodiment, the container is elongated in the form of a sample glass and extends in the longitudinal direction in the direction of the movement path on the holder; by means of the drive unit, the container is on an open trajectory along part of a circular arc with a given radius (r) and with two reversal points or along a straight line with two reversal points or along a spatial semi-ellipse with a region of strong change in curvature and two reversal points or on a closed trajectory guided tangentially back and forth along a spatial ellipse with two areas of strong change in path curvature and a given radius (r).

In order to achieve the cyclically traversed open or closed movement path with at least two areas of strong change in path curvature or at least two reversal points with high path acceleration taking place in these areas or reversal points, the drive unit consists of at least two eccentrically rotatably mounted eccentric wheels or eccentric rollers which are driven synchronously and which form a constant gap, within which a carrier is guided, which is pivotally supported at its lower end below the gap and which carries the holder for the container at its upper end above the gap, the gap rotating when the eccentric wheels rotate walks back and forth with the carrier.

Furthermore, in order to achieve an open movement path along part of a circular arc with a predetermined radius (r) and with two reversal points, the drive unit can consist of two gear wheels, the axes of rotation of which are rotatably supported in walls at a distance from one another and are driven synchronously by means of a toothed belt, on each Gear with the same eccentricity an eccentric is arranged, which define the constant gap between them, within which the carrier is guided, which defines the length of the radius (r) from its lower pivot point to the holder of the container, the container being tangential is arranged to the carrier.

In order to achieve the cyclically traversed closed spatial movement path with at least two regions of strong change in path curvature with large path acceleration taking place in these regions, a second drive unit of this type with eccentric rollers can be arranged offset by 90 degrees, in each case between the lower and upper eccentric rollers of the carrier is guided, which is designed as a round rod and is gimbally fastened at its lower end, whereby when the eccentric rollers rotate, the respectively formed lower and upper gap, mutually offset by 90 degrees, partly overlap and take the Hike back and forth; the roller pairs rotate on the gap.

A simple control of the drive unit and a simple construction of the device is possible if, according to a further feature, the drive unit comprises a DC motor, preferably with speed control.

The DC motor is advantageously designed for speeds between 30 and 500 revolutions per minute, preferably between 60 and 300 revolutions per minute. Taking the translation of the rotary movement into a double stroke movement of the carrier with the sample containers, these rotational speed values result in an optimal number of movements per unit of time, which is preferably between 100 and 200 double strokes per minute. Double stroke means the movement from a reversal point on the open movement path of the carrier to the other reversal point and back again to the first reversal point. A motor revolution preferably results in a double stroke of the carrier.

In order to enable simple input of process parameters, a memory device contains a program which queries the operating elements and controls the drive unit in accordance with their position.

Brief description of the drawing, in which: FIG. 1 shows a schematic side view of a device; FIG. 2 shows a front view of the device of FIG. 1, in which operating elements are shown

Figure 3 is a view of the drive unit Figure 4 is a view of the drive unit in three different

Movement positions Figure 5 is a partial view of the top view of the drive unit Figure 6 is a top view of the housing with the omission of the

Carrier and the bracket and showing part of the

Drive unit Figure 7 shows another drive unit to enable an Egyptian

Movement Figure 8 different possible movements of the container.

Preferred embodiment of the invention:

The device shown by way of example in FIG. 1 consists of a housing 1 with an inclined front wall 1 a and with side walls 1 b and 1 c, a support 2 standing vertically upwards and a mounting frame 3, preferably detachably mounted on the support 2, as a holder for sample containers 7, 7 '. , 7 ", 7" ', 7 "", preferably centrifuge glasses, which are firmly but releasably held within the receiving frame, which is arranged horizontally. The receiving frame 3 can in principle be designed for any number of containers. The housing 1, which is preferably made of a light but stable material, such as aluminum, contains a drive unit 12 for the movement of the carrier 2 and also an associated control, preferably on an electronic basis. The area in which the carrier 2 protrudes from the housing 1 is designed to allow the movement of the carrier 2 as an elongated hole to enable the movement of the carrier 2 and to prevent the ingress of dirt or moisture with an elastic bellows 4, preferably made of rubber , covered. The carrier 2 is preferably driven by the drive unit 12, which comprises a DC motor with speed control.

Preferably, the carrier 2 is mounted in the housing 1 in such a way that the receiving frame 3 always moves back and forth on a section of an arc between two opposite reversal points. Depending on the speed of the reversal of movement, very high forces act on the particles in the liquids in the reversal points, which may be in the sample containers, which ensures good mixing of different substances or liquids.

The carrier 2 is pivotally mounted at its lower end about a pivot point 8 and can be driven by means of a drive unit 12, which essentially consists of two synchronously driven drive wheels 10, 11. As a result, the container 7 is pivoted back and forth on a circular arc with the radius r, the container 7 being directed tangentially and horizontally with respect to its movement path in the rest position. The operating elements can advantageously be provided on the inclined front wall 1 a. As shown in FIG. 2, these are designed for easy input of any desired number of engine revolutions or of double strokes of the carrier per unit of time as a number keyboard 5 with keys from 0 to 9. The correct entry can then be confirmed via a separate entry key 5a. Furthermore, an on / off switch 5 b is integrated in the keyboard in the example shown.

In order to be able to switch between different operating modes - operation via the keyboard 5, 5a or control via an interface, for example via a computer - a switch key 5c is provided. Pressing a mode key 5d causes the device to be switched to a mode in which the desired number of revolutions per minute or the number of double strokes per minute can be entered via the numeric keypad 5.

Additional operating status keys 5e, 5f allow the switchover to operating states for test runs over a number of revolutions that can be selected again via the keyboard 5 or over a specific period of time, as well as a switchover to the input and editing mode for the number of revolutions or time for the actual one Operation with the respective samples, the values entered via the keyboard 5 to 5f, the respective current operating state of the device, possibly error messages, etc. can be read on an optical display unit 6.

Figures 3 to 6 show a technical embodiment of the drive unit 12, as used in the device within the housing 1. Ball bearings 25 are held within two walls 26, 26 ', through which axes 22, 23 are guided at a distance from one another, on which gear wheels 15, 16 are arranged adjacent to the wall 26, via which a toothed belt 18 runs for the synchronous drive of the gear wheels 15 , 16, one of which can be driven by means of a motor (not shown). One eccentric wheel 19, 20 is rotatably arranged on each of the gear wheels 15, 16, the eccentricity being indicated by the distance of the pivot points 19 ', 20' of the eccentric wheels 19, 20 from the axes of rotation 15 ', 16' of the gear wheels 15, 16. The eccentricity of the two eccentric wheels 19, 20 is the same, as a result of which a gap 21 which is constant in the inside width is formed between the eccentric wheels 19, 20. An elongated cuboid 14 is arranged in the center between the gear wheels 15, 16 and within the gap 21, which extends below the gear wheels 15, 16 and which extends parallel to the axes of rotation 22, 23 of the gear wheels 15, 16. At the lower end of the cuboid 14 there is an axis of rotation 24 which is suitably mounted within the walls 26, 26, 'by means of ball bearings 25 and which runs parallel to the axes of rotation 22, 23. Support rods 13, which correspond to the carrier 2 in FIG.

When the gears 15, 16 rotate, the eccentric wheels 19, 20 are taken along, so that the gap 21 moves back and forth in a vertical projection. The cuboid 14 is carried along by this gap 21 and thus pivoted back and forth about the axis of rotation 24. In order to minimize the friction, a ball-bearing outer slewing ring 27 is arranged on each of the eccentric wheels 19, 20 and rolls on the opposite surfaces of the cuboid 14 when the eccentric wheels 19, 20 rotate. In this way, the cuboid 14 or the support rods 13 describes a movement path which is part of an arc of a circle, each with a reversal point located at one end; this movement is shown in FIG. 4 for three different deflections of the cuboid 14 around its pivot point (17).

FIG. 7 shows an embodiment of the drive unit, which is used to achieve a cyclically traversed closed movement path with at least two areas of strong change in path curvature and with large path acceleration taking place in these areas with a given radius on a spherical shell. The drive unit consists of two gear wheels 28, 29, which in turn are held and driven synchronously, as in the previous example. An eccentric roller 30, 31 with the same eccentricity is arranged on each of the gear wheels 28, 29, which, when the gear wheels 28, 29 rotate, in turn form a constant driving gap, as described for the previous example. Above the eccentric rollers 30, 31 there are likewise eccentric rollers 30 ', 31' held on gear wheels 28 ', 29', which are identical to the lower pair of eccentric rollers 30, 31. In this way, the eccentric rollers 30 ', 31' also define a driving gap of constant width between them. Through the overlapping gaps between the lower eccentric rollers 30, 31 and the upper eccentric rollers 30 ', 31' rotated here by 90 °, a carrier 32 is guided, which is designed as a round rod to prevent the movements of the pairs of eccentric rollers 30, 31 and 30 '. , 31 'to be able to follow. The lower end of the carrier 32 is gimbaled, so List of reference numerals:

1 housing la sloping side wall lb, c vertical side walls

2, 32 carriers

3 bracket, like mounting frame

4 rubber bellows

5a Enter key

5b on-off switch

5c shift key

5d fashion button

5e, f operating status keys

6 display unit

7, 7 ', 7 ", 7"', 7 "" sample tubes or centrifuge tubes

8 pivot point

9 axis

10, 11 drive wheels

12 drive unit

13, 13 ', 13 "support rods in various deflections

14 oblong cuboid

15, 16, 28, 29 gears

15 ', 16' axes of rotation of the gears

17 center of rotation of the cuboid

18 timing belts

19, 20 eccentric wheels

19 ', 20 "pivot points of the eccentric wheels

21 movable gap

22, 23 axes of rotation of the gears

24 axis of rotation of the cuboid

25 ball bearings

26, 26 'walls

27 Outside slewing ring

30, 31 eccentric rollers

Claims

Claims:

1. A method for mixing / separating substances of different mass and / or density located in at least one container (7,7 ', 7 ", 7'", 7 ""), which is held in a holder (2,3), which is moved by a drive unit (12) taking the container (7,7 ', 7 ", 7'", 7 "") with it, characterized in that the container (7,7 ', 7 ", 7'", 7 "") or the holder (2, 3) along a cyclically traversed open or closed trajectory with at least two areas of strong curvature change or at least two reversal points with large trajectory acceleration taking place in these areas or reversal points by the drive unit (12), to the exclusion a rotation of the container (7,7 ', 7 ", 7'", 7 "") is moved substantially tangentially back and forth.

2. The method according to claim 1, characterized in that the container is elongated in the form of a sample glass (7, 7 ', 7 ", 7'", 7 "") and in its longitudinal extent in the direction of the movement path on the holder ( 2, 3) extends, the sample glass (7,7 ', 7 ", 7'", 7 "") tangentially on an open movement path along part of an arc of a circle with a predetermined radius (r) and with two reversal points or along a straight line is essentially tangentially moved back and forth with two reversal points in the ends of the trajectory.

3. The method according to claim 1 or 2, characterized in that the container (7,7 ', 7 ", 7'", 7 "") along an ellipse or along an "oo" each with two areas of strong curvature change on a closed Movement path or along a semi-ellipse with a region of strong change in path curvature and two reversal points on an open path of movement and in each case a predetermined radius (r) on a spherical shell is moved essentially tangentially back and forth.

4. Device for mixing / separating substances of different mass and / or density located in at least one container (7, 7 ', 7 ", 7'", 7 ""), which is held in a holder (2, 3), which is movable by a drive unit (12) together with the motor, taking the container (7, 7 ', 7 ", 7'", 7 "") with it, characterized in that that the container (7, 7 ', 7 ", 7'", 7 "") or the holder (2, 3) by means of the drive unit (12) along a cyclically traversed open or closed trajectory with at least two areas of strong curvature change or at least two reversal points with great path acceleration taking place in these areas or reversal points, excluding rotation of the container (7, 7 ', 7 ", 7'", 7 ""), is guided essentially tangentially back and forth.

5. The device according to claim 4, characterized in that the container is elongated in the form of a sample glass (7,7 ', 7 ", 7'", 7 "") and in its longitudinal extent in the direction of the movement path on the holder ( 2,3) extends and by means of the drive unit on an open trajectory along part of a circular arc with a predetermined radius (r) and with two reversal points or along a straight line with two reversal points or along a semi-ellipse with a region of strong change in curvature and two reversal points or on one closed trajectory along an ellipse with two areas of strong curvature change and a given radius (r) on a spherical shell is guided substantially tangentially back and forth.

6. The device according to claim 4, characterized in that to achieve the cyclically traversed open or closed trajectory with at least two areas of strong curvature change or at least two reversal points with large trajectory acceleration occurring in these areas or reversal points, the drive unit (12) from at least two Eccentrically rotatably mounted eccentric wheels (15,16) or eccentric rollers (30,31), which are driven synchronously and which form a constant gap (21), within which a carrier (2,32) is guided, which is at its lower, below of the gap (21) is pivotally supported and the upper (above the gap (21) end located the holder (3) for the container (7,7 ', 7 ", 7"', 7 "") carries , wherein when the eccentric wheels (15, 16) rotate, the gap (21) moves back and forth with the carrier (2, 32).

7. The device according to claim 6, characterized in that to achieve an open trajectory along part of an arc with a predetermined radius (r) and with two reversal points, the drive unit (12) consists of two gears (15, 16) whose axes of rotation (22, 23) are rotatably supported at a distance from one another in walls (26, 26 ') and are driven synchronously by means of a toothed belt (18), an eccentric wheel (19, 20) being arranged on each gear (15, 16) with the same eccentricity which define the constant gap (21) between them, within which the carrier (2, 32) is guided, which extends from its lower pivot point (17) to the holder (3) of the container (7, 7 ', 7 ", 7 "', 7"") defines the length of the radius (r), the container (7, 7', 7", 7 "', 7"") being arranged tangentially to the carrier (2,32).

8. The device according to claim 6, characterized in that to achieve the cyclically traversed closed trajectory on a spherical shell with at least two areas of strong curvature change with large web acceleration taking place in these areas above the drive unit, the eccentric rollers (30,31), one second such drive unit with eccentric rollers (30, 31) is arranged offset by 90 degrees and in each case between the lower and upper eccentric rollers the carrier (32) is guided, which is designed as a round rod and is gimbally fastened at its lower end, with rotation of the eccentric rollers (30,31) the respectively formed lower and upper gap, mutually offset by 90 degrees, partly overlap and move back and forth with the carrier (32) and rotate on the gap.

9. Device according to one of the preceding claims, characterized in that the motor of the drive unit (12) is a DC motor, preferably with speed control, which is designed for speeds between 30 and 500 revolutions per minute, preferably between 60 and 300 revolutions per minute the carrier (2, 32) or the holder (3) is capable of performing between 100 and 200 double strokes per minute.