EP4259319A1

EP4259319A1 - Device for dispersing media, in particular a substance in a liquid

Info

Publication number: EP4259319A1
Application number: EP21824511.6A
Authority: EP
Inventors: Beat Troxler; Wolfgang NIENS
Original assignee: KINEMATICA AG
Current assignee: KINEMATICA AG
Priority date: 2020-12-10
Filing date: 2021-11-30
Publication date: 2023-10-18
Also published as: WO2022122465A1; CH718147B1; CH718147A2

Abstract

A device for dispersing media, in particular a substance in a liquid, comprises a housing (15) having a dispersing chamber (16), inside which is an impeller (20) which can be rotated by means of a drive member (19) for the purpose of stirring the media, at least one inlet (13, 14) for each medium and at least one passage (17, 18) for the dispersed media. The external jacket of the dispersing chamber (16) consists of an internal wall (15', 15'') in the housing (15). The internal wall (15', 15'') is shaped, and the impeller (20) is arranged rotatably therein, in such a way that, in the operating state, the rotating impeller (20) forms at least two suction regions (13', 14') and at least two pressure regions (17', 18'), by means of which each of the suction regions (13', 14') is able to draw in one medium and, after stirring, these media can be expelled dispersed in the pressure regions (17', 18'). The cross section of the external jacket of the dispersing chamber (16) is oval or of a similar shape, and the impeller (20) is arranged therein in such a way that it can be rotated about a central axis (A). This allows the liquid and the powder to be sucked in separately from one another and, in addition to obtaining a homogeneous dispersion more rapidly, it is also possible to improve the performance of the device.

Description

Device for dispersing media, in particular a substance in a liquid

The invention relates to a device for dispersing media, in particular a substance in a liquid, which has a housing with a dispersing chamber, an impeller rotatable therein by a drive element for stirring the media, at least one inlet for each medium and at least one passage for comprises the dispersed media, the outer casing of the dispersing chamber being formed by an inner wall in the housing, according to the preamble of claim 1 . In a known device for dispersing a substance in a liquid according to publication EP 1 674 151, a dispersing chamber, a liquid inlet, a substance inlet and an outlet are formed in a housing and a rotatable impeller for stirring the liquid is arranged eccentrically therein . These inlets and the outlet are arranged laterally to the impeller.

In the operating state when the impeller is rotating, a liquid ring is formed in the dispersing chamber by the liquid sucked in by one side of the impeller, which is limited on the outside by the inner wall of the housing and on the inside, so that there are free spaces between the blades of the impeller, which are denoted cavities, form with different volumes and on the other side of the impeller they cause substance to be sucked in through the substance inlet or ejection of the substance mixed with liquid through the outlet. These inlets or the outlet are accordingly placed laterally in the area of the free spaces formed in the suction or pressure area. This negative or positive pressure in these free spaces formed within the liquid ring is generated by the eccentric arrangement of the impeller, depending on whether the outer sides of the impeller are in the spaced area or close to the housing wall. The material inlet and the liquid inlet are arranged on the suction side on opposite sides of the impeller and the outlet is arranged on the pressure side, with each of them having a sickle-shaped, round or other shape. The liquid and the substance can be sucked or pumped from the top into the dispersing chamber and then into a mixing chamber of a dispersing device. However, this arrangement has the disadvantage that the liquid is not sucked in and therefore has to be supplied with an additional pump and the adjustment of the pump pressure of the liquid can lead to excess pressure or cavitation depending on the operating conditions.

With this tried and tested device, the wetting of the powder is not fully guaranteed and, in addition, the supplied powder tends to cake when the media are sucked in and ejected, at least in the inlet area, which can lead to malfunctions. In addition, it is often necessary to recirculate through several passes in order to achieve a sufficiently homogeneous dispersion. In addition, the permissible maximum working pressure is limited due to the lack of symmetry of the forces on the impeller.

The invention is based on the object of improving a device of the type mentioned at the outset in such a way that faster and more efficient dispersion of the supplied media, in particular the substance in the liquid, is made possible without the device having to be constructed in a more complex manner and also preventing cavitation can become.

According to the invention, this object is achieved by the features of claim 1 . The inner wall of the housing for the formation of the outer jacket of the dispersing chamber is shaped in such a way and the impeller is rotatably arranged in it that in the operating state the rotating impeller forms at least two suction and two pressure areas, through which a medium can be sucked in and out in the suction areas ejectable in dispersed form upon agitation at these pressure ranges.

The inner wall in the housing is very advantageously designed with an oval or similar cross-sectional shape and the impeller is arranged therein so that it can rotate about a central axis. This design of the dispersing chamber and the central mounting of the impeller result in considerable advantages in various respects, because two suction and two pressure areas are created in the operating state. The liquid and in particular the powder can be drawn in separately from one another. In this way, in addition to the improved wetting and thus faster achievement of a homogeneous dispersion, the performance of the device can also be increased without the external dimensions of the device having to be increased.

There is also a further advantage, because the radial forces acting on this mixing tool are canceled out due to the oval and the associated almost symmetrical geometry of the inner wall of the housing and the central arrangement of the impeller, and the permissible working pressure can thus be significantly increased . This is due to the fact that the two suction and also the two pressure areas are exactly opposite. The invention provides for the dispersing chamber in the housing to be followed by a dispersing device with a rotor and a stator with meshing toothed rings, by means of which further refinement or deagglomeration of the dispersion can be effected. By means of the two passages created from the two pressure areas on the inside into an annular chamber in the dispersing device, a more uniform and faster distribution of the media therein can also be achieved. As a result, the homogenization can be achieved as a further advantage in many applications in one pass in the desired quality.

Furthermore, the media inlets located on one side of the impeller in each suction area can be connected as a bypass through at least one transverse through-opening. This means that mixed media can be passed through the device at least a second time during recirculation in such a way that they are fed into one inlet and part of this through the open through-opening as a bypass into the other inlet and from there into the dispersing chamber. The inlet for the supply of fabric is preferably closed. This allows the vacuum to be reduced and prevents cavitation in the dispersing chamber.

The invention and other advantages thereof are explained in more detail below using exemplary embodiments with reference to the drawing. It shows: 1 shows a longitudinal section through the device according to the invention with the connecting lines and the containers for the media;

2 shows a schematic plan view of the impeller in the housing and the suction and pressure areas occurring in the operating state within a liquid ring;

FIG. 3 shows a schematic longitudinal section through the device according to FIG. 1 during recirculation of the media with an open or closed inlet for the powder; and

4 shows a schematic longitudinal section through the device and the dispersing device with stator and rotor located therein.

1 shows a device 10 for dispersing media, by means of which mainly a liquid 11 is wetted with a powder 12 and mixed in such a way that no deposits or baked-on granular, sand-like and/or lump-like residues remain. This device 10 can be used in a wide variety of areas, for example in the food, chemical, pharmaceutical, cosmetic, metallurgical area or the like. Liquid or creamy mixtures such as milk, flour, chocolate products etc. can be produced as food, while liquid or viscous coloring or other chemical substance mixtures can be produced in chemistry. It is particularly suitable for dispersing color powder with a chemical liquid. The device 10 comprises a multi-part housing 15 with a dispersion chamber 16, an impeller 20 rotatable therein by a drive member 19 for stirring the media, at least one inlet 13, 14 for each medium and passages 17, 18 for the mixture formed . An inner wall in the housing 15 forms an outer casing of the dispersing chamber 16

In addition, a dispersing device 25 with a rotor 21 and a stator 22 is arranged in the housing 15 below the dispersing chamber 16, the rotor 21 being driven by the same drive element 19 as the impeller 20, for which purpose a drive shaft 24 protruding into the housing 15 is provided. The rotor 21 and the stator 22 are each designed in the form of a disk, which thus forms an annular chamber 26, and on the outside they each have two, as shown, or only one or more intermeshing sprockets 21', 22', which the media to the outside in a refined manner and conducted into an annular outlet chamber 27 to an outlet 23 and via a line 34 mixed into a container 35 . In the case of the latter, a line 36 for air separation leads away at the top and a supply line 39 into the inlet 13 is provided on the underside.

As illustrated in FIG. 2, the inner wall 15′, 15″ of the housing 15, which forms the outer jacket of the dispersing chamber 16, is shaped according to the invention and the impeller 20 is rotatably arranged therein so that in the operating state in the dispersing chamber 16 form at least two suction areas 13', 14' and at least two pressure areas 17', 18' by the rotating impeller 20, through which at the suction areas 13', 14', a medium can be sucked in and, after stirring, can be discharged in these two pressure areas 17', 18' in a dispersed manner.

This outer jacket of the dispersing chamber 16 formed by the inner wall 15', 15" in the housing 15 is expediently designed with an oval cross-section and the impeller 20 is arranged therein so that it can rotate about a central axis A, so that the outer sides 29 of the blades 28 of the impeller 20 run along the inner wall close to the opposite approximately straight surfaces 15' and turn with a changing distance ai, a2 at the rounded surfaces 15'' of the inner wall.

In the operating state, a liquid ring 11' is formed in the dispersing chamber 16 by the rotating impeller 20 and is delimited by the outer jacket of the dispersing chamber. and thus the two suction 13', 14' and pressure areas 17', 18', this being dependent on the direction of rotation D of the impeller 20, which is indicated counterclockwise.

In the device 10, the impeller 20 is arranged to be rotatable about an axis A and the inlets 13, 14 for one medium each are positioned on the upper side at a respective suction area 13', 14' of the impeller 20, in which the Move along the outer sides 29 of the wings 28 close to one and the other approximately straight surface 15' of the oval outer shell and in the over- with the changing distances a walk. In contrast, the passages 17, 18 in the stator 22 of the mixed media are arranged on the underside of the impeller 20 following a respective pressure area 17', 18', in which the outer sides 29 of the vanes 28 at the transition from the changing distances ai , a2 transition from the rounded surfaces to the approximately straight surfaces 15' of the outer shell.

The suction areas 13', 14' that arise when the impeller 20 rotates are each shown in FIG. 2 with a round cross section, which corresponds to the tubular inlets 13, 14, and the pressure areas 17', 18' are shown in the shape of a crescent. The tubular inlets 13, 14 are each dimensioned with a different diameter, the smaller one being assigned to the powder feed, which is adapted to the volume ratio of the feed quantities. Effectively, however, both the suction and the pressure areas are formed by the free spaces present between the blades 28 of the impeller 20 with the volumes 28' of different sizes in the areas explained above. It goes without saying that the inlets and outlets can have simple cross-sectional shapes or ones that are adapted to the suction and pressure areas.

According to FIG. 3, in the device 10 within the scope of the invention, the inlets 13, 14 located on the upper side of the impeller 20 at a suction area 13', 14' are connected to one another by at least one transverse through-opening 30 as a bypass, wherein therein as well as in the inlet 14 for the powder 12 an actuatable closing element 31, 32 is assigned, which advantageously interact in such a way that one or the other is open or closed. In a recirculation, the mixture of the media already mixed in the device 10 and returned to the container 35 is preferably fed from the container 35 into one inlet 13 and part of it through the open passage opening 30 as a bypass into the other inlet 14 and from there passed into the dispersing chamber 16, the inlet 14 for the powder 12 being closed by the closing element 32. The mixture is then, as explained above, refined or deagglomerated in the dispersing chamber 16 and subsequently in the dispersing device 25 and is carried away back into the container 35 or as the end product. In principle, the closing element 32 for the powder 12 could also be at least partially open.

With this transverse through-opening 30 as a bypass, it is possible for the recirculation to process approximately twice the amount with approximately the same performance of the device 10 . In addition, a vacuum in the suction area at the inlet 14 can be reduced and thus cavitations in the dispersing chamber can be prevented.

The containers 35, 37 of the media are expediently placed above the device 10 and a supply line 39, 38 leads from each of them into an inlet 13, 14 on the upper side of the housing 15 when the impeller 20 is arranged. Pumps can therefore be dispensed with and the supply of the media is made possible not only by gravity but also by the suction force in the dispersing chamber. The supply line 39 from the container 35 is advantageously equipped with a controllable valve, not shown in detail, so that the supply or the amount of liquid from the container holder 35 can be controlled/regulated. In addition, the supply line 38 from the container 37 is equipped with the closing element 32 as a likewise controllable valve, so that the substance supply can be regulated.

In Fig. 4, the rotor 21 and the stator 22 of the dispersing device 25 is illustrated in more detail, in which the outside of these two, as shown, or only one or more interlocking sprockets 21 ', 22' can be seen, from circular to axial Protruding teeth 21", 22" exist at regular intervals from one another, which are each rod-shaped and are arranged without contact with one another. When the rotor 21 rotates, the media flowing radially outwards are further efficiently deagglomerated by the teeth 21", 22" moving past one another, and an almost complete homogenization can thereby be achieved.

The closing element 31 in the passage opening 30 is preferably designed as a rotary slide, in which the opening 31' can be shaped in a flow-optimized manner so that no caking or cavitation damage occurs.

The invention is sufficiently demonstrated with the exemplary embodiment explained above. However, it could also be explained by further variants.

In principle, the housing wall forming the outer shell of the dispersing chamber could be designed differently instead of being oval in shape, so that, for example, even three suction areas and three pressure areas could be before would be created in which this housing wall could have a triangular shape with rounded corners. The impeller arranged centrally therein would be guided with its outer sides of the blades close to the side surfaces of the triangle, but at a corresponding distance in the rounded corners. Instead of a triangle, a polygon with rounded corners could also be provided with a plurality of suction or pressure areas, preferably with the same number of corners.

The blades 28 of the impeller 20 are preferably straight and radially outwardly shaped as illustrated. Of course, these could also be arched, shovel-shaped, or formed in some other way.

Likewise, the dispersing device can be omitted or both the rotor and the stator as well as the meshing ring gears can be designed differently than shown. The teeth could be provided with cross-sections other than rod-shaped, for example segment-shaped or knife-shaped. Instead of the teeth, transverse openings, for example bores, can be provided in the rims. The rotor could also be rotated by a separate drive at a different speed than that of the impeller. The axis of rotation (A) of the impeller and the rotor is aligned vertically, as this is advantageous. It could also be arranged horizontally.

In principle, the impeller could not be centric to the outer shell of the dispersing chamber, as illustrated with the axis of rotation A in Fig. 2. but at a distance from the center towards the narrow and/or the longer side of the oval dispersing chamber. The blades of the impeller would then have to be correspondingly shortened in length, if necessary, so that they run along the straight surfaces of the inner wall and do not touch them. In this way, the two suction areas with their passage cross section and thus the suction volume of the two media can be changed in relation to one another. The inflow quantity of the liquid is advantageously kept smaller compared to the other medium or gas, in order to reduce the engine output.

It is also possible that one pump each is used to support suction and/or evacuation at the inlets and outlets.

As mentioned, as a further advantage of the invention, the homogenization can be achieved in one pass with the required quality. A transverse passage opening is then not required as a bypass at the inlets, but the mixture can be routed directly as the end product or into a container, preferably with at least one line 36 for air and/or gas separation and away from it.

Claims

PATENT CLAIMS

1. A device for dispersing media, in particular a substance in a liquid, which has a housing (15) with a dispersing chamber (16), an impeller (20) rotatable therein by a drive member (19) for stirring the media, at least one inlet (13, 14) each for one medium and at least one passage (17, 18) for the dispersed media, the outer casing of the dispersing chamber (16) being enclosed by an inner wall (15', 15'') in the housing ( 15), characterized in that this inner wall (15', 15") is shaped in such a way and the impeller (20) is rotatably arranged in it that in the operating state the rotating impeller (20) causes at least two suction areas (13 ', 14') and form at least two pressure areas (17', 18'), through which a medium can be sucked in each of the suction areas (13', 14') and after stirring in these pressure areas (17', 18 ') are dispersed omissible.

2. Device according to claim 1, characterized in that the outer casing of the dispersing chamber (16) formed by the inner wall (15', 15'') in the housing (15) has an oval or similar cross-sectional shape and the impeller (20) is arranged therein, preferably rotatable about a central axis (A), so that the outer sides (29) of the blades (28) of the impeller (20) are close to the opposite, approximately straight surfaces (15') and at a varying distance (a ₁ , a ₂ ) run along the adjacent rounded surfaces (15") of the inner wall.

3. Device according to claim 1 or 2, characterized in that the impeller (20) is arranged to be rotatable about a vertical axis (A) and the inlets (13, 14) of the media are on the upper side in a respective suction area (13', 14') of the impeller (20), in which the outer sides (29) of the blades (28) are close to one or the other approximately straight surface (15') of the oval outer casing and consequently to the rounded surfaces ( 15”) along.

4. Device according to claim 3, characterized in that the passages (17, 18) of the media lead away on the underside in each case a pressure area (17', 18') of the impeller (20), in which the outer sides (29) the vane (28) in transition from the changing one

Distance (a) at the rounded surfaces (15") transition to the almost straight surface (15') of the outer casing.

5. Device according to one of Claims 1 to 4, characterized in that in the operating state the rotating impeller (20) causes a liquid ring (11') delimited by the outer casing of the dispersing chamber (16) and inside it between the vanes (28) of the impeller (20) in each case free spaces with different volumes (28') and thus these each form at least two suction (13', 14') and pressure areas (17', 18').

6. Device according to one of claims 1 to 5, characterized in that at least one dispersing device (25) with a rotor (21) and a stator (22) is arranged in the housing (15), preferably with interlocking sprockets (21 22') and when the rotor (21) rotates, the dispersed medium can be conveyed outwards from the passages (17, 18) through these sprockets (21 22') and a refinement, a deagglomeration and/or a Dissolution of the dispersion causes.

7. The device according to claim 6, characterized in that the dispersing device (25) forms an annular chamber (26) into which the passages (17, 18) of the dispersing chamber (16) open on the inside and on the outside preferably an annular outlet chamber ( 27) is provided, so that the medium can be conveyed from the inside to the outside between the rotor (21) and the stator (22).

8. The device according to claim 6 or 7, characterized in that the rotor (21) and the stator (22) of the dispersing device (25) are disc-shaped and on the outside each have one or more rows of gears (21 22') that mesh with one another. have, wherein the ring gears (2T, 22') consist of protruding teeth (21", 22") at regular intervals from one another, which are each designed in the form of rods.

9. Device according to claim 6 or 7, characterized in that the rotor (21) and the stator (22) of the dispersing device (25) have one or more rows of interlocking rings on the outside, which are provided with transverse openings, for example bores , are trained.

10. Device according to one of claims 1 to 9, characterized in that on one side of the impeller (20) in each case a suction area (13 ', 14') located inlets (13, 14) of the media through at least a transverse through-opening (30) can be connected as a bypass, this through-opening (30) and the inlet (14) for one medium, in particular for the substance, each having an actuatable closing element (31, 32).

11. The device according to claim 10, characterized in that the mixed media can be passed through the device (10) at least a second time during recirculation, in which in the operating state the mixed media in the one inlet (13) and part of it through the opened passage opening (30) as a bypass into the other inlet (14) and from this into the dispersing chamber (16), wherein the inlet (14) for the supply of material is preferably closed.

12. The device according to claim 10 or 11, characterized in that for the recirculation, an outlet line (34) leading away from the outlet (23) of the housing (15) leads into a container (35) and from there via a supply line (39) to Inlet (13) and part of it through the through-opening (30).

13. Device according to claim 12, characterized in that the containers (35, 37) for the media are located above the housing (15) and on the underside there is a supply line (39, 38) each to an inlet (13 , 14) on the upper side of the housing (15) in an arrangement of the impeller (20) with a preferably vertical axis alignment (A).