FI92475C - Stirrer for aseptic purposes - Google Patents

Abstract

An impeller for aseptic purposes which is rotatable by inductive drive means in a predetermined direction within a vessel for stirring and mixing sterile fluids. The impeller (10) comprises a plurality of radially extending stirring blades (15) on an outer surface of the impeller and bearing means on an inner surface of said impeller for rotatably mounting the impeller on the vessel wall. The impeller is further provided with through-flow passages which outwardly extend from the inside of the impeller in a direction away from an axis of rotation, through orifices (25, 26) which are situated on the outer sr-face of the impeller immediately adjacent each blade (15), seen in said direction of rotation, so that cleaning fluid can be sucked through the passages due to a low pressure region occurring behind each blade.

Description

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MIXER FOR ASEPTIC PURPOSES

The invention relates to a mixer for aseptic purposes, which is to be rotated in a predetermined direction of rotation by an inductive drive device, in a tank for mixing and agitating sterile liquids.

It is known to stir the liquid contained in a closed vessel by magnetic coupling between an external hydrating actuator and a completely separate internal stirrer (see e.g. US-42092-1559). At the same time, it is a known problem to clean and sterilize the inside of the mixer vessel. It has been proposed to provide the mixer with radial channels which allow the cleaning liquid / e.g. water or superheated steam to penetrate the inner surfaces of the mixer 20 and pass through its bearing members.

However, truly effective sterilization can usually only be performed with a relatively long sustained purification period.

It is an object of the invention to provide a mixer which has a significantly improved self-cleaning capacity so that sterilization with hydryl or other liquid can take place in a substantially shorter time.

Therefore, the agitator according to the invention is characterized by blade flow channels extending from the inside of the agitator 30 from the rotating shaft of the agitator to orifices located on the outside of the agitator in the direction of rotation .

According to a preferred embodiment of the invention, the bearing members comprise a shaft pin which is central. o 7 r.

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placed in the end wall delimiting an inward cylindrical recess in the silo wall from the area of the bottom of the silo.

Preferably, the surrounding portion surrounds the cylinder-5 ground recess at a certain small distance, which allows the passage of cleaning fluid between the cylindrical recess and the surrounding portion of the mixer.

The foregoing and other features of the invention will now be described in more detail with reference to the accompanying drawings, in which Figure 1 shows a plan view of a mixer according to the invention, Figure 2 is a partially sectioned side view of a mixer without a drive and Figure 3 is a sectional view of Figure 1 along.

The mixer 10 shown in the figure is placed in a mixing vessel, the bottom wall 11 of which is shown in Figure 2. This vessel is intended for use in large process equipment, e.g. in the manufacture of medicaments, 20 and is provided with a suitable amount of filling, discharge and storage. Various sterile liquids are placed in a container where they are mixed with a mixer 10, after which the finished mixture is discharged from the container.

The agitator bearing and drive devices 25 are shown in Figure 2 and include an inwardly cylindrical recess 12 in the tank wall 11 extending from the bottom of the tank, which recess is welded in so that there are no holes in this part of the tank wall. The agitator 10 is mounted on an intermediate pin 13 of the sleeve 10a, which is centrally located in the end wall 14, which delimits a cylindrical recess 12a.

The agitator 10, like the silo walls 11, is mainly made of stainless acid-resistant steel 35 with its turned hinges 15 and central lifting rings 16. The agitator comprises a circumferential portion 17 surrounding a cylindrical recess 12 and a k • • · m 4 sittåå lukumåårån permanent magnets 18 which are in-inductive linkage to the same number of permanent magnet 19 with which is disposed a rotor 20. This implies rotors-ri jårjestetty pyoritettåvåksi the direction of arrow 21 (figure 1) 5 in the direction perinteisellå non-, described såhkomoottorilla, wherein the recesses ympåroivå mixer 10 works.

Figure 3 visible when, and working the mixer is equipped with låpivirtauskanavilla 22, 23, which extend from the mixer 10 comprises a ulospåin the axis of rotation 24 suuauk-10 GE UNIQUE 25,26, which are arranged mixer-ulkosi close to the flank of the edellå levyå 15 viewed from the direction of arrow 21 direction of rotation. In this arrangement, the cleaning fluid is sucked through the channels by means of a vacuum acting on the back of the plate. In this way, the cleaning liquid 15 can be sucked past the recess 12 and the shaft pin 13 while the mixer is rotating, after which the liquid can pass out of the mixer mainly through the radial channels 22,23.

The invention is not limited to the embodiment presented above, but several modifications are possible within the scope of the following claims. For example, the number of channels and orifices may be greater or less. The pyrethylene member of the mixer may be formed in another way.

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Claims (3)

An aseptic stirrer which rotates in a predetermined direction of rotation through inductive drive means (20), inside a tank (11) for stirring and mixing sterile liquids and comprising a number located on an outside of the stirrer (10) , generally directed agitator blades (15), and on an inside of the same means (10a, 13) for storing the agitator at the tank wave (11), characterized by flow channels (22, 23) extending from the inside of the agitator (10), in an outward direction from a rotational shaft (24) to orifices (25, 26) located on the outside of the agitator closest to the present blade (15), seen in said rotational direction, so that cleaning fluid can be sucked out through the channels (22, 23), using the negative pressure acting on the blade back. 2. A stirrer according to claim 1, characterized in that the storage means comprise a shaft pin (13) which is centrally located on a spirit wall (14) which defines a cylindrical recess (12) directed in the tank wave from the bottom of the tank bottom (12). 11). 3. A stirrer according to claim 1 or 2, characterized by a peripheral portion (17) surrounding the cylindrical recess (12) having a certain small gap distance to allow the passage of cleaning fluid between the cylindrical recess (12) and the peripheral portion (17) of the stirrer (10).