EA004133B1 - Device for continuous magnetic separation from liquids - Google Patents

Abstract

1. A device for continuous magnetic separation liquid mixtures, comprising a receiver of separating particles and separating chamber, made as horizontally located rotating drum, containing a continuous magnet assembly as figure of revolution segment, fixed immobile in lower part, and partially covered by pan, provided with inlet and outlet branches connected with tanks for separating liquids and for discharge liquid respectively, characterized in that it's further provided with a tank for flushing liquid, which is located by the way to supply said liquid onto upper generatrix of the drum, and a receiver of separating particles is made as a trough and located along the drum so, as said particles to be washed down into it by steam of flushing liquid in upper descending part of rotation arc of the drum. 2. Device according to claim 1, characterized in that the pan is semicylinderical and embraces the drum in a zone of placing of continuous magnet, which is semicylinderical. 3. Device according to claim 1, characterized in that the orientation of the magnetic field of continuous magnet is perpendicular to rotation axis of the drum. 4. Device according to claim 1, characterized in that maximal gradient of magnetic field id oriented to the lower part of the drum, plunged in separating liquid, and minimal gradient of magnetic field is oriented to upper part of the drum, flushing by flushing liquid. 5. Device according to claim 1, characterized in that the inlet and outlet branches of separating chamber are cornerwise located in upper part of the pan.

Description

The invention relates to the field of magnetic devices for the separation of components from liquid mixtures. The most promising application of this device is for large-scale isolation of biologically active components from complex mixtures, including cells, bacteria, viruses, their subparticles and certain types of molecules.

Devices are known that contain a container for the liquid to be cleaned, supply and discharge connections, a branch pipe for removing impurities, a magnetic system rotating on the rotor, and sludge collecting elements (1-6), where the magnetic system is made in the form of a segment enclosing the rotating pipeline (7).

However, all these devices are designed primarily for cleaning technical fluids and are unsuitable for the selection of sensitive to mechanical effects of biological objects. In addition, all of the above devices are difficult to manufacture.

A device for continuous magnetic separation, consisting of a non-magnetic cuvette with a magnetized wire, installed near the narrow side wall of the cuvette. A wire magnetized by an external magnetic field creates a magnetic field component transverse to the longitudinal axis of the wire. The magnetic gradient is distributed over the entire space of the cuvette and affects the particles passing through the cuvette with the flow of liquid. Depending on the orientation of the magnetic field in the cuvette, the diamagnetic and paramagnetic particles of the mixture are displaced to the opposite walls of the cuvette and collected in separate collections (8).

However, this device in real conditions is extremely inefficient due to the turbulences of the fluid flow in the cuvette.

The device for magnetic cell separation described in US Pat. No. 5,536,475 (9) consists of two tanks and a base on which a rocking chair is movably fixed. A container is installed on the rocking chair, which receives a mixture of cells and superparamagnetic particles from the first tank. At the same time, in the extreme positions of the rocking chair, the particles are either attracted by means of a permanent magnet to the wall of the container, or released into the washing liquid coming from the second tank.

However, this device is unsuitable for continuous magnetic separation of relatively large volumes of liquid mixtures.

A device for continuous magnetic separation of components from mixtures (10) contains at least one separation chamber with multiple channels and many permanent magnets. A periodic magnetic retention of superparamagnetic particles with affinely attached components occurs in it. Each retention cycle is completed by the spatial separation of the separation chamber from the permanent magnets. In this case, the retained components enter the chamber for the regeneration of particles and the release of the associated components of the mixture.

The disadvantage of this device is the cyclical nature of the processes of retention and release of components, which requires complex regulation of the flow of the initial mixture, washing solutions and shared components.

A device (11) is known, which is a flowing, slowly rotating horizontal chamber consisting of several combined magnetic parts. Each part consists of an alternating electric current coil covering the chamber and a pair of permanent magnets located further along the flow of the fluid and rotating with the chamber. The rotation of the chamber simulates a state of low gravity, dramatically slowing down the process of sedimentation of particles in a separated mixture. This achieves good contact of affine paramagnetic particles with non-magnetic components of the mixture that specifically react with them. The gradient of an alternating magnetic field created by the coils of alternating current provides translational and rotational oscillations of superparamagnetic particles, increasing the mixing, while the permanent magnets attract these particles to the walls of the chamber.

However, this device has significant drawbacks: 1) difficult to manufacture (contains sliding sections of the inlet and outlet of the rotating chamber), 2) high-energy-consuming (due to high electricity consumption in AC coils), 3) does not provide a truly continuous separation process, t. to. requires periodic repetition of magnetic retention cycles of magnetic particles with their subsequent release, by removing permanent magnets and washing the particles off the walls of the chamber with a washing liquid.

A device (12) for continuous magnetic separation of liquid mixtures is known, which includes a separable particles receiver and a separation chamber, which is made in the form of a horizontally arranged rotating drum containing a permanent magnet in the form of a circular segment fixed stationary in its lower part, and partially overlapping with a cuvette equipped with inlet and outlet nozzles connected to reservoirs for the divided liquid and for the spent liquid, respectively. In the device according to the specified source, the selection of detachable magnetic particles is organized as follows: the particles are mechanically cleaned from the surface of the drum in the initial part of the trajectory of their movement.

Such an impact on the detachable particles makes this device unsuitable for the selection of sensitive to mechanical effects of biological objects.

The present invention is the creation of a simple, effective gentle device for the separation of liquid mixtures, suitable for working with biological objects.

The task is achieved by the fact that the separation chamber of the device is made in the form of a horizontally arranged rotating drum of non-magnetic material, inside which a semi-cylindrical permanent magnet is fixed on a fixed axis of rotation, and the drum is immersed in a cuvette through which the partial fluid flows. The orientation of the magnetic field of the permanent magnet is perpendicular to the axis of rotation of the drum, and the maximum gradient of the magnetic field is directed to the lower part of the drum, immersed in the fluid to be divided. At the same time, the minimum gradient is directed to the upper part of the drum, washed by the washing liquid.

The semi-cylindrical cuvette is installed in the area of the semi-cylindrical magnet, with the possibility of holding magnetic particles on the drum surface in the flow of the divided liquid in the lower part of the drum and releasing the washing liquid in the upper descending part of the drum rotational flow. The tray, installed in the uppermost descending part of the arc of rotation of the drum, is made so that the magnetic particles captured by the surface of the drum are washed into it by the washing liquid. The inlet and outlet nozzles of the separation chamber are located diagonally in the upper part of the cuvette.

As a result of the implemented structural changes, the device makes it possible with high efficiency to continuously separate magnetic particles from the stream of the treated liquid.

The proposed device is shown in FIG. 1. The drum 1 of a non-magnetic material rotates around a semi-cylindrical permanent magnet 2 mounted on a fixed axis 3 with the orientation of the magnetic field perpendicular to the axis of rotation 3 of the drum. The drum is rotated on bearings (not indicated in the drawing) by an electric motor 4 with a reducer by means of an actuator 5. The lower half of the drum, which is in the area of the permanent magnet 2, is immersed in a semi-cylindrical cuvette 6, into which the divided liquid 8 with magnetic particles 9 flows continuously from the tank 7 The inlet 10 and outlet 11 nozzles are located diagonally at the top of the cuvette. This ensures maximum filling of the cuvette separated by the liquid and reaches the longest path of particles 9 in the zone of action of the permanent magnet 2.

When fluid 8 flows through cuvette 6, particles 9 are attracted by the influence of a constant magnetic field gradient to the lower surface of rotating drum 1 and are removed from fluid flow 8. Fluid released from particles is collected in collector 12 through nozzle 11. As a result of rotation of drum 1, particles 9 reach a position outside the action of a constant magnetic field gradient and are held on the surface of the drum outside the flow of the divided liquid 8 only due to adhesion forces. On the descending part of the arc of rotation of the drum under the influence of the flow of wash liquid 13 coming from the tank 14, poorly held particles 9 are washed off on the tray 15 and collected in the receiver 16.

Example 1

Experiments were performed on a model mixture of magnetic particles in a salt solution. Iron-carbon powder Fersar coated with dibutyrylchitin with cortisol labeled with radioactive iodine was used as particles. Particle size ranged from 0.1 to 2 microns. 200 mg of particles were suspended in 500 ml of 1% solution No. 1С1 and placed in a reservoir for a partial liquid. The cuvette was filled with 150 ml of a 1% NaCl solution. Distilled water was poured into the wash tank. The diameter of the drum is 10 cm, its length is 16 cm, a semi-cylindrical permanent magnet with a magnetic field strength of 0.2 Tesla, the speed of rotation of the surface of the drum is 1 cm / s. The flow rate of the partial fluid through the cuvette is 1 ml / s, the flow rate of the flushing liquid to the drum is 0.2 ml / s. The concentration of particles was determined by the radioactivity of liquid samples measured on a Gammacount instrument. The salt concentration was determined on an I-130 ion meter with a sodium selective electrode, pre-calibrated on standard NaC1 solutions. Calculated the relative content of particles and salt in the collection 12 and the receiver 16 compared with their content in the original mixture.

Example 2

Experimental conditions as in example 1, except that the flow rate of the partial fluid through the cuvette is 5 ml / s.

The results of measuring the relative content of magnetic particles and salt in examples 1 and 2 are given in the table.

The relative content of particles and salt in the receiver and the collection at different speeds of flow of the separated liquid through the cuvette

Flow rate Particle content,% Salt content,% Receiver Compilation Receiver Compilation 1 ml / s 3 97 92 eight 5 ml / s sixteen 84 91 9

Literature

1. Avt.Sv. USSR № 1057074, MKI B 01Ό 35/06, publ. 11/30/83. Bul No. 44

2. Avt.Sv. USSR № 1487994, MKI V 03S 1/00, B 01Ό 35/06, publ. 06/23/89. Bul No. 23

3. Avt.Sv. USSR № 1519753, MKI B 01Ό 35/06, B 03B 5/34, publ. 11/07/89. Bul No. 41

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Claims (5)

1. A device for the continuous magnetic separation of liquid mixtures, including a receiver of separated particles and a separation chamber, which is made in the form of a horizontally located rotating drum containing a permanent magnet in the form of a segment of a body of revolution, fixed motionless in its lower part, and partially overlapping with the cell equipped with inlet and outlet pipes connected to reservoirs for shared liquid and for spent liquid, respectively, characterized in that it is supplemented It is equipped with a washing liquid reservoir, which is placed so as to supply the specified liquid to the upper forming part of the drum, and the receiver of detachable particles is made in the form of a tray and placed along the drum so that these particles are washed off by a flow of washing liquid in the upper descending part of the arc of rotation drum. 2. The device according to claim 1, characterized in that the cuvette is made semi-cylindrical and covers the drum in the area of the permanent magnet made semi-cylindrical. 3. The device according to claim 1, characterized in that the orientation of the magnetic field of the permanent magnet is perpendicular to the axis of rotation of the drum. 4. The device according to claim 1, characterized in that the maximum gradient of the magnetic field is directed to the lower part of the drum immersed in a shared liquid, and the minimum gradient of the magnetic field is directed to the upper part of the drum washed by the washing liquid. 5. The device according to claim 1, characterized in that the inlet and outlet pipes of the separation chamber are located diagonally in the upper part of the cell.