DE29917365U1 - Device for homogenizing and / or dispersing a flowable material - Google Patents

Description

Schröder & Boos Mixing and Plant Technology GmbH & Co. KG , Am Bredenmoor 4, 27578 Bremerhaven

Device for homogenizing and/or dispersing a flowable material

The invention relates to a device for homogenizing and/or dispersing a flowable material, in particular for emulsions or dispersions for the cosmetic or pharmaceutical industry, according to the preamble of claim 1.

Devices are known for homogenizing and/or dispersing, in particular cosmetic or pharmaceutical emulsions or dispersions, which have a container with an agitator for the flowable material. Usually, in the area of the lowest point of the container there is a so-called homogenizer with a stator and a rotor, with the help of which the flowable material is sucked in from the bottom area of the container and homogenized and/or dispersed as it flows through the stator/rotor arrangement.

The state of the art contains differently designed devices for returning the homogenized/dispersed material to the container.

The different designs strive to take into account several requirements and tasks that are generally placed on the homogenizing/dispersing device.

A particular requirement is the reliable homogenization/dispersion of so-called minimum (fill) quantities. Minimum fill quantities are fill quantities of the device that are significantly smaller than the nominal fill quantities for which the device is designed. Firstly, with reference to the function of the device when operating with the (large) nominal fill quantity, a return line is known in the prior art which returns from the pressure side of the stator/rotor arrangement into the container in an upper area, usually above the fill level of the nominal fill quantity. In this way, the freshly homogenized/dispersed material is conveyed upwards onto the material, while the homogenizer sucks the material from the bottom area of the container for homogenization/dispersion. When operating with minimum quantities, the problem arises that this quantity is so small that it does not even fill the return line and is therefore deposited in the return line after homogenization/dispersion instead of being conveyed back into the agitator container.

In view of this problem, in addition to the operating mode often referred to as flow homogenization with return of the material via an external line, the state of the art also includes an operating mode often referred to as circulation homogenization, in which - usually for processing small quantities - the processed material is returned directly in the area of the homogenizer to the agitator container.

The German utility model 8428385.8 describes a homogenizer that uses an adjustment device to raise and lower a stator/rotor unit so that the pressure side of the unit in the raised position returns the material directly to the bottom of the agitator tank (circulation homogenization), while in the lowered position it flows into the return line (flow homogenization). The disadvantage here is the high construction effort. For safe and reliable raising and lowering, which makes the device expensive and, due to the many seals and moving parts required, maintenance-intensive and prone to repairs.

According to EP 0204294 B1, the stator/rotor arrangement of the homogenizer is fixed in the area of the container bottom and is supported by a "plate".

The bell has an inlet opening in the middle of the top to the suction side of the stator/rotor arrangement. This bell can be raised from the bottom of the container so that an annular outlet gap is formed which directs the processed material from the stator/rotor arrangement directly back into the bottom area of the container (circulation homogenization). When the bell is lowered, this gap is sealed and a valve is opened instead, which is located in the bottom of the container in the area covered by the bell and leads to the external return line (flow homogenization). Another disadvantage of this design is the large number of moving parts and seals as well as "dead water" zones where product deposits can lead to contamination, whereby the dead water zones necessarily result from the complex arrangement of the elements.

In the device known from German utility model 29606962 U1, an essentially ring-shaped outlet gap (from the stator/rotor arrangement) leading into the interior of the container is covered by a disk provided with recesses that is rotatably mounted centrally on the stator. In one rotational position, the recesses are aligned with recesses on the stator and in this position (circulation homogenization) form outlet openings in the bottom area of the container, while in another rotational position (flow homogenization) the recesses are closed. In this case, the material flows through a line for returning the processed material to the upper area of the agitator container. This design also results in a disadvantageously high construction effort for the mechanism for rotating the disk, which leads to high manufacturing costs, maintenance effort and susceptibility to repairs.

As is clear from what has been said so far, the stator/rotor arrangement serves on the one hand for homogenizing/dispersing by generating high shear stress in the material flowing through it, and on the other hand for pumping or conveying the material. Furthermore, there is regularly the need to add additives to the material or to introduce cleaning fluids into the device during the pumping function of the stator/rotor arrangement. For this purpose, connection openings with suitable flange mechanisms are usually provided on the homogenizer, and for good efficiency as close as possible to the suction side of the stator/rotor arrangement. Appropriate supply lines can be connected there. However, because the suction side of the known homogenizers is usually on the top and is made inaccessible to such connection openings by the radially circumferentially arranged pressure-side outflow.

The arrangement of the opening in devices according to the state of the art represents a design problem.

The present invention is based on the object of creating a device for homogenizing and/or dispersing even small amounts (minor quantities) of a flowable material, which is structurally simple.

This object is achieved by a device having the features of claim 1. Advantageous embodiments are specified in the subclaims.

The device according to the invention has a container, preferably an agitator container with an agitator, for a flowable material, in particular for emulsions or dispersions such as ointments, doughs, gels or creams in the field of the pharmaceutical, chemical, cosmetic or food industry. In the area of the bottom of the container, the device according to the invention has a device for homogenizing/dispersing, preferably with a stator/rotor arrangement, the suction side of which opens into the bottom of the container, preferably at its lowest point. The pressure side of the stator/rotor arrangement leads into a first and an alternatively selectable second return line, which have a long path or a short path: The short path of the first return line and the long path of the second return line both open back into the container, albeit at different points. The return opening of the short path is in the lower area of the container, preferably in the area of the container bottom. The return outlet of the long path, on the other hand, is preferably located above the filling level of the nominal filling quantity of the device according to the invention.

In order to be able to choose between the short and the long path, the device according to the invention can have a controllable valve in each of the two return lines, which can then be opened and closed in opposite directions or together to select the path of the return.

In particular, the valve of the short path is preferably a lifting plate valve, which is preferably encased in one piece with an elastic material. The casing of the valve tappet is preferably designed as a bellows and made of PTFE. In this way, the elements of the valve, which is preferably pneumatically operated, are not exposed to the corrosive influence of the flowable material.

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and do not contaminate it. In addition, the casing of the valve plate also acts as the valve seal of the cover in the seat of the valve in the wall of the agitator tank. In this case, the top of the valve plate in its closed position is preferably arranged essentially flush with the inner wall of the tank in order to avoid "dead water" areas in the return line downstream of the valve, where the agitator of the agitator tank cannot be effective.

The valve plate, in particular of the lifting plate valve arranged in this way, preferably opens outside the interior of the container, i.e. against the direction of flow into the return line, so that stirring or scraping elements that can be moved in the container can move unhindered. The return opening of the return line is preferably covered with a diaphragm with radially directed deflection openings, whereby the diaphragm is as flush as possible with the container bottom or curves slightly into the container so that it does not interfere with the movement of stirring or scraping elements. In its closed position, the top of the valve plate is as close as possible to the bottom of the diaphragm. To open, the valve plate moves away from the diaphragm against the direction of flow into the return line. The diaphragm is preferably rotatable in order to be able to align the deflection openings, which divert the flow direction of the return flow from the axial direction of the return line into directions with a radial component, in definable directions. This makes it possible to set optimal flows, for example with regard to the direction of action of the agitator.

Connection openings leading to the outside, in particular for feeding in additives or attaching sensors, in particular temperature sensors, are arranged in the area of the mouth of the suction side of the stator/rotor arrangement. The stator/rotor arrangement acts on feed lines that are connected to the connection openings according to the invention with a particularly high pumping efficiency because the connection openings are preferably located in a housing wall of the device according to the invention immediately upstream of the suction side of the stator/rotor arrangement. This arrangement is made possible according to the invention in that even in the circulation homogenization operation defined at the beginning, the return of the processed material does not take place on the circumference of the stator/rotor arrangement (i.e., the arrangement does not flow around it, as is usual in the prior art), but in this operating mode too, the processed material is returned via an external return line, but now in the

In comparison with the flow homogenization mode, the liquid is returned to the agitator tank via a much shorter path.

In order to achieve a high pumping efficiency, the homogenization/dispersion device according to the invention is preferably essentially rotationally symmetrical with respect to the rotor axis and preferably has a cylindrical, and particularly preferably a circular cylindrical, housing. The upper end face of the cylindrical housing (that is the wall of the cylindrical housing which represents the cover side of the cylinder, i.e. the side surrounded by the jacket surface of the cylinder) is then flanged to the bottom of the container and forms the mouth of the suction side of the rotor/stator arrangement as an opening leading through into the agitator container. Projecting downwards from the agitator container, the peripheral wall of the cylindrical housing is available, preferably over its entire circumference, for the arrangement of connection openings according to the invention and then leads directly into the rotor/stator arrangement; In a preferred embodiment of the invention with a vertical rotor axis, a housing face is arranged concentrically with the housing on the inside of the flange side, through which a drive unit can preferably be flanged, which, as is known and customary, consists of a motor with a drive shaft and, if necessary, an intermediate gear. The preferred arrangement of the rotor according to the invention directly on the freely accessible face of the cylindrical housing (and concentric with this) enables the use of commercially available drive units with extremely low construction effort and is therefore particularly easy to manufacture and cost-effective.

The pressure side of the stator/rotor unit can therefore also be constructed particularly simply according to the invention, in that an outlet chamber opens into the return line in a ring shape between the unit and the concentric housing shell surface at at least one point on the circumference of the shell surface, which then preferably branches into the short flow path and the long flow path that can be selected alternatively by means of a corresponding valve circuit in order to choose between the operating modes of circulation homogenization and flow homogenization. According to the invention, however, two outlets can also lead out of the outlet chamber, for example, one of which leads directly into the short flow path and the other directly into the long flow path.

The described preferred design of the homogenization dispersion device with the cylindrical housing shape thus ensures an extremely

simple construction with - in summary - a flange opening on the top that leads into the bottom area of the agitator tank, an upper area of the cylinder surface for the connection openings that adjoins this on the underside, an area of the cylinder surface that continues from there on the underside for the at least one opening of the return line - in this area the cylinder surface concentrically surrounds the stator/rotor arrangement arranged in the housing. This is followed by the lower end face of the cylinder for flanging the drive unit of a conventional rotary drive unit for the rotor.

With a two-part housing structure, the invention also ensures easy accessibility of the housing, in particular for inspections. For this purpose, the lower end wall of the cylindrical housing is preferably designed as a cover, which can be quickly removed using quick-release fasteners, preferably used for fastening, in particular in the manner of screw clamps. At least the rotor, but preferably the entire stator/rotor unit, is also preferably attached to this cover on the inside, so that this stator/rotor unit and the drive unit coupled to the outside can also be removed together with the cover. To close it again, the cover on the housing can then be quickly and precisely repositioned using conventional centering screws or dowel pins and can also be securely fastened again very quickly using the quick-release fasteners.

A preferred embodiment is described below with reference to the accompanying drawings, in which:

Figure 1 is a partially sectioned side view of the floor area

an agitator tank of a device according to the invention including a homogenization/dispersion device including return lines;

Figure 2 is a partially sectioned side view of a valve of the

Return line as a section from Figure 1.

Figure 1 shows a device 2 for homogenizing/dispersing a flowable material 1 with an agitator container 4, of which only its bottom area is shown with a circular cylindrical housing 6 of a stator/rotor unit 7 flanged in the area of its lowest point. The rotor axis 8 is the same.

the cylinder axis of the housing 6, i.e. the stator/rotor unit is coaxial with its housing 6. The housing 6 is flanged with a first of its two cylinder end faces, which forms a suction-side inflow opening 10 for the flowable material from the container 4 into the housing 6 to the stator/rotor unit, to a flange collar 12 in the region of the lowest point of the wall 14 of the container 4 by means of screws 16 evenly distributed around the circumference and sealed in the usual way, e.g. by means of an O-ring seal.

The described inflow of the flowable material from the container 4 into the stator/rotor unit, after it has passed through the inflow opening 10 into the housing 6, leads through an area of the housing where connection openings 20 are arranged on the circumference of the wall 18 forming the cylinder jacket. One of the connection openings 20 can be seen and, e.g. designed as a threaded hole, is intended for attaching suitable coupling sleeves (not shown), with the help of which supply lines for additives and cleaning agents, but also flange seats for sensors, e.g. temperature sensors or pH probes, can be attached.

The area where the stator/rotor arrangement 7 is attached is connected to the underside of this area of the housing 6 with the connection openings 20 on the housing surface 18. It is separated by an inflow aperture 23 from the interior of the housing 6 above it, through which the flowable material flows into the stator/rotor arrangement. The inflow aperture 23 has a central inflow bore 24 that is concentric with the housing 6 and the stator/rotor arrangement 7. The flowable material flows into the stator/rotor arrangement 7 and is conveyed radially outwards by the latter into an annular outflow chamber that surrounds the stator/rotor arrangement 7 in a ring shape and is delimited on the outside by the housing surface 18.

In this area of the casing surface 18 there is an opening into a return line 28, which branches into a short path 30 and a long path 32. The path of the flowable material that is thrown out of the stator/rotor arrangement 7 can then be selected by either opening a valve 34, which is arranged in the short path 30 of the return line 28, and closing a valve (not shown) in the long path 32 - thus the short path 30 would be selected in particular for the operation of the device 2 according to the invention with small amounts of the flowable material - or with the opposite connection

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The long path 30 can be selected for the valves, particularly when operating with a nominal filling quantity. In this case, the flowable material flows back into the agitator container 4 through a return opening 36 slightly above the filling level 38 of the nominal filling quantity of the flowable material 1.

First, the mounting of the stator/rotor arrangement 7 in the housing 6 and its drive by a drive unit 40 are described below, followed by the structure and function of the valve 34 in the short path 30 of the return line 28, the return opening 42 of which is located in the lower region of the container 4 and closer to the opening 10 of the suction side of the stator/rotor arrangement 7 than the return opening 36 of the long path 32.

The stator/rotor arrangement 7 is rotatably mounted in a cover 44 or annular flange which forms the lower end face of the cylindrical housing 6 opposite the inflow opening 10. The cover 44 is flanged to the end face of the housing 6 by means of quick-release fasteners 46 in the manner of a screw clamp. The drive unit 40 is flanged to the cover 44 coaxially (with respect to the common axis 8) with the stator/rotor arrangement 7 and the housing 6 as well as the cover 44, specifically on the outside, i.e. from below to the cover 44 when the latter is fastened to the housing 6. For the sake of clarity, only a bearing housing 48 for a drive shaft and a lower fastening flange 50 on the bearing housing 48 are shown of the drive unit 40, where a motor (not shown) is flanged to the bearing housing 48. This design allows the cover 44, together with the rotor mounted therein (also beforehand), the stator/rotor unit 7 and the entire drive unit 40 flanged to the cover 44, to be removed and reattached very easily and quickly for the purposes of inspection, maintenance and/or repair.

The structure of the valve 34 in the short path 32 of the return line 28 is described below with additional reference to Figure 2, where the housing 56 of the valve 34 is shown broken open to reveal a closing body 52 and a bellows 54 as corrosion and contamination protection, which is encased by a valve tappet (not shown). The closing body 52, designed as a plate, is lifted by a pneumatic drive device 58 (Figure 1) via the valve tappet hidden in the bellows 54. The drive unit 58 thus moves the valve plate 52 between the open position of the valve 34 shown in Figure 2, in which the valve plate 52 is located outside the interior of the container 4, and a closed position (not shown).

Position where the valve disk 52 is positioned in an associated valve seat 60 substantially flush with the inside of the wall 14 of the container 4.

The return opening 42 of the short path 30 of the return line 28 into the container 4, which is surrounded by the valve seat 60, is covered by a diaphragm 62 with radially directed deflection openings 64. In addition to its sectional side view in Figure 2, above, the diaphragm 62 is also shown in a half plan view. The diaphragm 62 bulges slightly from the wall 14 of the container 4 into the interior of the container 4, where it adjoins the valve plate 52 very closely in its closed position. In this way, there is advantageously hardly any "dead water" area downstream of the valve plate 52 in its closed position, where otherwise the blades and scrapers of the agitator (not shown) that is active in the agitator container 4 could not reach.

The orifice 62, with its radially directed deflection openings 64, ensures that the return flow of the flowable material through the return opening 42 into the container 4 does not exit directly from the return opening 42 at right angles to the container wall, but gives the return flow a tangential component with respect to the container wall 14. In order to adjust the tangential component in its radial direction with respect to the return opening 42, the orifice 62 is rotatably mounted on the otherwise conventionally designed fastening flange of the valve 34 on a flange collar 66 which surrounds the return opening 42, by means of elongated holes 68 for fastening screws 70 for fastening the valve 34 to the collar 66.

Claims (27)

1. Device for homogenizing and/or dispersing a flowable material 1 , in particular for emulsions or dispersions,
with a container ( 4 ) and a homogenization/dispersion device, the suction side ( 24 ) of which is connected in a lower region ( 10 ) of the container ( 4 ) to its interior and the pressure side ( 26 ) of which is connected to a first return line ( 28 , 32 ) which leads into an upper region ( 36 ) of the container ( 4 ) and through which the flowable material ( 1 ) can be introduced back into the container ( 4 ),
characterized in that the pressure side of the homogenization/dispersion device is connected to a second return line ( 28 , 30 ) which leads into a lower region ( 42 ) of the container ( 4 ) into its interior, so that the flowable material ( 1 ) can be introduced selectively into the lower region ( 42 ) and/or upper region ( 36 ) of the container ( 34 ). 2. Device according to claim 1, characterized in that the second return line ( 30 ) opens into a bottom region ( 42 ) of the container ( 4 ). 3. Device according to claim 1 or 2, characterized in that at least one of the return lines ( 28 , 30 , 32 ) has a controllable valve 34 with a closing body for opening and closing the return lines ( 28 , 30 , 32 ). 4. Device according to the preamble of claim 1 or claim 3, characterized by a lifting plate valve ( 34 ) with a valve plate ( 52 ) and a valve tappet for opening and closing at least one of the return lines ( 28 , 30 ). 5. Device according to claim 4, characterized in that the valve tappet and the valve plate ( 52 ) of the lifting plate valve ( 34 ) have a one-piece casing ( 54 ) made of an elastic material. 6. Device according to claim 5, characterized in that the casing has a bellows ( 54 ). 7. Device according to one of claims 3 to 6, characterized in that the closing body ( 52 ), in particular the valve plate ( 52 ), is arranged in its open position outside the interior of the container ( 4 ). 8. Device according to one of claims 3 to 7, characterized in that the closing body ( 52 ), in particular the valve plate ( 52 ), in its closed position is substantially flush with the inside of a wall ( 14 ) of the container ( 4 ). 9. Device according to one of claims 3 to 8, characterized in that the valve ( 34 ) is pneumatically or manually operated. 10. Device according to one of the preceding claims, characterized in that at least one of the return lines ( 28 , 30 ) is covered in the region of its mouths ( 36 , 42 ) into the container ( 4 ) with a diaphragm ( 62 ) with radially directed deflection openings ( 64 ). 11. Device according to claim 10, characterized in that the cover is substantially flush with the inside of a wall ( 14 ) of the container ( 4 ) or curves into the interior of the container ( 4 ). 12. Device according to claim 3 and claim 10 or 11, characterized in that the closing body ( 52 ), in particular the valve divider ( 52 ), in its closed position tightly adjoins the aperture ( 62 ). 13. Device according to one of claims 11 or 12, characterized in that the diaphragm ( 62 ) is rotatable and can be fixed in different rotational positions and the deflection openings ( 64 ) therefore have a determinable direction. 14. Device according to one of the preceding claims, characterized in that the first return line ( 28 , 32 ) opens into the container ( 4 ) above the filling level ( 38 ) of a nominal filling quantity of the flowable material ( 1 ). 15. Device according to the preamble of claim 1 or according to one of the preceding claims, characterized in that the homogenization/dispersion device ( 5 ) has a divisible housing ( 6 ). 16. Device according to claim 15, characterized in that the housing ( 6 ) is cylindrical. 17. Device according to claim 15 or 16, characterized in that the housing ( 6 ) is arranged coaxially to a rotor of a stator/rotor arrangement ( 7 ) of the homogenization/dispersion device ( 5 ). 18. Device according to one of claims 15 to 17, characterized in that an inflow opening ( 10 ) on the suction side, arranged between the interior of the container ( 4 ) and the housing ( 6 ), is delimited by an annular flange ( 12 ). 19. Device according to claim 18, characterized in that the flange ( 12 ) is integrated into a wall ( 14 ) of the container ( 4 ). 20. Device according to claim 18 or 19, characterized in that an annular flange ( 22 ) is formed on a lower front end of the housing ( 6 ). 21. Device according to claim 20, characterized in that a drive unit ( 40 ) for driving a rotor of a stator/rotor arrangement of the homogenization/dispersion device ( 5 ) has a connecting flange ( 44 ) and is detachably mounted to the housing ( 6 ) together with this connecting flange ( 44 ). 22. Device according to claim 15 to 21, characterized in that the housing parts of a divisible housing or the connecting flange ( 44 ) and the annular flange ( 22 ) are detachably fastened to one another by means of quick-release fastener elements ( 46 ), which are designed in particular in the manner of screw clamps. 23. Device according to claim 22, characterized in that the housing parts or the connecting flange ( 44 ) can be clamped together in any rotational position by means of the quick-release fastener elements. 24. Device according to one of the preceding claims, characterized in that the return line ( 28 ) is led out of the homogenization/dispersion device ( 5 ) essentially tangentially to a stator/rotor arrangement ( 7 ) of the homogenization/dispersion device. 25. Device according to one of the preceding claims, characterized in that the suction side ( 24 ) of the homogenization/dispersion device ( 5 ) is arranged at the lowest point ( 10 ) of the container ( 4 ). 26. Device according to one of the preceding claims, characterized in that the homogenization/dispersion device ( 5 ) has outward-leading connection openings ( 20 ) in the region of the suction side ( 24 ) of the homogenization/dispersion device ( 5 ). 27. Device according to claim 16 and 26, characterized in that the connection openings ( 20 ) are arranged in the peripheral wall ( 18 ) of the cylindrical housing ( 6 ).