JPH07788A - Magnetic stirrer - Google Patents

Abstract

PURPOSE: To provide a stirring device which is safe for sterilizing by disposing a contactlessly operating coupling between a stirring operating shaft and a stirring means, and arranging the stirring operating shaft inside a pipe. CONSTITUTION: A driving shaft 2 is rotatably fixed inside a bearing and a protective pipe 1 by bearings 7, 8, is put inside a pipe 12 having a fine aperture, and a magnetic disk 5 as a coupling provided with a permanent magnet at the lower end is fixed. The outside of the pipe 12 having the fine aperture is partially wrapped by an impeller head 13, a polarized permanent magnet facing the magnetic disk 5 is disposed inside the impeller head 13 and an angular moment is contactlessly relayed from the driving shaft 2 to the impeller head 13 by the magnetic force between the magnetic disk 5 and the permanent magnet. Further, vanes 4 are fixed as a stirring means to the impeller head 13. Thus, sealing between the stirring operating shaft of rotation and the rotating fine aperture is ensured, which enables the cleaning and sterilizing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a stirring action shaft, a drive unit, a stirring unit, and a non-contact acting coupling for transmitting a driving moment from the drive unit to the stirring unit via the stirring action shaft. The present invention relates to a stirrer provided.

[0002]

2. Description of the Related Art A rotary stirrer using a permanent magnetic force is known as an example of this kind of stirrer. The transmission of the rotational moment between the drive motor and the stirring shaft follows the principle of magnetically radiative coupling. The outer coupling part is connected to an electric motor with a continuously controllable transmission and displaces a movement-synchronous rotary movement to the inner coupling part via a gap. In addition, a driving technique using water pressure, air pressure, or the like can be applied. In the space between the inner and outer coupling parts, a slit cylinder made of a paramagnetic material is arranged, which is connected to the internal space of the autoclave, for example via a cooling cylinder, and has an internal drive system. Is closed to the internal space of the autoclave to prevent pressure leaks. The cooling cylinder holds the high autoclave temperature away from the magnet system and bearings.

The slit cylinder with the closed cooling cylinder forms a common volume with the internal space of the autoclave. Inside the cooling cylinder, a slit cylinder of a stirring shaft is arranged and supported by a bearing according to each case, and packing is provided inside the slit cylinder and inside the closed cooling cylinder, and the autoclave space is provided. It is separated from the cooling cylinder by the volume of the slit cylinder, as the case may be, thereby protecting the bearing of the stirring shaft from the autoclave atmosphere. A stirring action shaft that freely rotates in the internal space of the autoclave projects beyond the packing. This free protruding bearing at the end of the shaft is a prepared problem and thus the shaft tends to easily deviate and vibrate under reaction forces.

[0004]

Particularly in microbiological processes, a seal must be ensured between the rotary stirring shaft and the rotating slit, for example the cooling cylinder. Otherwise the result would be a total charge loss.

This packing and bearing arrangement constitutes an unbroken point of weakness in the known magnetic stirrers and has a particular disadvantage, especially in areas of use which require preservative and sterilization. The upper part of the slit cylinder, for example the cooling cylinder, presents a static air cushion with no ventilation, which is not absolutely safe for sterilization of the autoclave, nor is it just safe. The bearing must not be lubricated past it. The stirring shaft cannot be assembled to any length without suitable bearings. Facilitated bearings and packings inside the slit cylinder create an uncontrollable area within which microorganisms can survive.
Also, disposable packings with blocking substances cannot satisfactorily solve this problem.

The object of the present invention is to overcome the disadvantages of known stirring devices.

[0007]

This problem is solved by providing a non-contacting coupling between the stirring action shaft and the stirring means, and disposing the stirring action shaft inside the cylinder.

[0008]

The cylinder acts as a guide cylinder for the stirring shaft. With it it is possible to carry out various lengths and the bearing support of the shaft can be brought up to the immediate side of the coupling. Normal industrial materials can be installed inside the guide tube without any problems. There is no useless band in this cylinder. It can be cleaned without problems and can be sterilized. In addition, it does not require supplementary slip ring packing, which is more permeable to bacteria. The products in the autoclave are hermetically sealed to the environment.

The formation according to the invention is arranged in such a way that the stirring means on the cylinder are held in rotational movement, in particular by means of plain bearings, and the bearings are in particular lubricated by the medium to be stirred. Vibrations are avoided by the bearings on the fixed cylinder. The average life of the bearing is increased. In special cases, radial bearings are sufficient, and in the secondary case, the axial support of the stirring means is magnetic.

In still another formation of the present invention, the stirring action shaft inside the cylinder is bearing-supported at at least two positions. The eccentricity of the stirring shaft known from the technical point of view is advantageously avoided by this measure. The critical condition is the critical rotational speed of the shaft. Also, under inconvenient structural boundary conditions, the agitation means can be structurally prepared at optimal locations for agitation and mixing.

The stirring means has an inner surface partially enclosing the cylinder,
Forming as an impeller with an outer surface and at least one guide hole connecting both surfaces serves to improve the self-cleaning properties of the stirring means. By driving the stirring means, the inner area around the bearing is cleaned by the constantly mixed product. When cleaning, the cleaning fluid also reaches locations in the bearing area that are difficult to access.

The tilting of the guide holes by the connection allows product or cleaning fluid to flow out of the stirring means when the tank is emptied. The airtight separation of the tank interior space is achieved by installing a packing or sealing surface at the drive end of the cylinder. The fixing of the tank of the stirring means is facilitated by the cylinder presenting an assembled flange at the drive end.

The disposition of the stirring device is facilitated by the provision of a second coupling between the drive and the stirring shaft. In the temperature-critical process, it is advantageous if the tube is provided with an intermediate space so that it can be heated or cooled.

For the same purpose, it is advantageous to mention that the cylinder itself is particularly double-walled so that it can be cooled or heated. This feature of the stirring means is particularly advantageous when the stirring means is used in a tank for microbial processes.

Structurally, when the driving machine is arranged inside the cylinder, the stirring shaft can be omitted in particular, and the stirring device is further simplified.

[0016]

The present invention will now be described with reference to the drawings, in which more advantageous details of the drawings will be understood. Each figure is illustrated.

FIG. 1 is a sectional view in the axial direction of a magnetic stirrer using a magnet according to the present invention. 1 is a bearing and a protective cylinder,
The drive shaft 2 is rotatably fixed in the inside by bearings 7 and 8. The bearing 7 and the lower end of the protective cylinder 1 are made up in the shape of a pot to close the bearing 7 and form a guide cylinder. A drive shaft 2 is contained in the slit cylinder 12, and a magnet disk 5 provided with some permanent magnets is fixed to the lower end of the drive shaft 2. The outside of the slit cylinder 12 is partially wrapped by the impeller head 13. Inside the impeller head 13, opposed to the magnet disk 5, a pair of opposed polarization permanent magnets (not shown) are arranged, and are driven in a non-contact manner by the magnetic force between the magnet disk 5 and the permanent magnet. The rotation moment is relayed from the shaft 2 to the impeller head 13. A blade 4 is fixed to the impeller head 13 as a stirring means by a rod. The bearing support of the impeller head 13 is provided by a slide bearing 6, which is the slit cylinder 1
It is installed on a shaft 14 formed downward from 2.

The internal recess having the surface 15 of the impeller head 13 is connected to the outer surface 16 of the impeller head 13 by the guide hole 3. This guide hole 3 partly directed radially outward by the rotation of the impeller
Shows a certain pumping effect and causes the fluid in the pot-shaped hollow space of the impeller head 13 to flow to the outside. As a result, the inner surface of the impeller head 13 is constantly cleaned with the product fluid, and a self-cleaning effect is obtained.

The upper end of the bushing 1 leads to a guide surface 17 with a closed mounting flange 18. Guide surface 17
A packing groove with a packing 11 is formed therein, which closes the guide surface 17 and the mounting support 19 in the tank wall 20. In FIG. 1, the mounting support 19 and the tank wall 20 are shown in broken lines.

The drive shaft 2 is connected to a drive unit 10 via a coupling 9 and a transmission 21. The drive 10 and the transmission 21 are coaxial, and the transmission 21 is directly fixed to the flange 18.

[0021]

As a result, a very space-saving and robust stirrer construction is realized and the disadvantages of known stirrers are overcome.

If determined, a fixed winding may be arranged inside the guide tube 1 as a driving machine, and a rotating field is generated by the corresponding steering means, for example, known treatment control means, without contact. The required driving moment is supplied for the stirring means.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a magnetic stirrer of the present invention.

[Explanation of symbols]

 1 Guide cylinder 2 Stirring shaft 3 Guide hole 4 Stirring means 5 Coupling 6 Sliding bearing 7,8 Bearing 9 Coupling 10 Driving machine 11 Packing

Claims (12)

[Claims] 1. A non-contact coupling (5) is provided between the stirring action shaft (2) and the stirring means (4),
The stirring action shaft (2) is arranged inside the cylinder (1), and a driving moment is passed from the driving machine (10) to the stirring action shaft (2) via the coupling (5) which is magnetically coupled and acts in a non-contact manner. A magnetic stirrer that relays to the stirrer (4) via. 2. Stirring means (4) are rotatably held in the barrel (1), in particular by means of a plain bearing (6), and the plain bearing (6) is preferably lubricated by a medium which is agitated. The magnetic stirrer according to claim 1. 3. The magnetic stirrer according to claim 1, wherein the stirring action shaft (2) is supported by bearings in at least two places inside the cylinder (1). 4. The stirring means (4) comprises an inner (15) partly enclosing the tube (1) and an outer surface (16) and at least one guide hole (3) connecting both surfaces. Formed as an impeller,
The magnetic stirrer according to claim 2 or claim 3. 5. Magnetic stirrer according to claim 1, 2, 3 or 4, characterized in that the guide holes (3) are inclined. 6. Magnetic stirring according to claim 1, characterized in that the cylinder (1) presents a packing (11) or packing surface (17) at the drive-side end. apparatus. 7. The magnetic stirrer according to claim 1, wherein the cylinder (1) has a mounting flange (18) formed at the end on the drive side. 8. A drive (10) and a stirring action shaft (2)
A second coupling (9) is arranged between the first and second parts (1) to (7).
The magnetic stirrer according to the item. 9. The magnetic stirrer according to claim 1, wherein the cylinder (1) has an internal space and is formed so that it can be heated or cooled. . 10. Cylinder (1) is capable of cooling or heating itself and is particularly double-walled for this purpose. 2. A magnetic stirrer according to item 1. 11. The magnetic stirrer according to claim 1, wherein the stirrer is used in a tank for a microbiological process. 12. The driving machine (10) is arranged in the cylinder (1), and in particular, the stirring action shaft (2) is eliminated, and the driving machine (10) is arranged in any one of claims 1 to 11. The magnetic stirrer described.