EP3498365B1 - Stirrer device - Google Patents

Description

State of the art

The invention relates to a stirring element device, in particular a stirring element device that does not penetrate the wall, according to the preamble of claim 1.

There are already known stirrer devices with lattice and/or leaf-shaped stirrer blades that go along the wall and generate a radial flow at least locally. An open geometry in an upper region also brings about an axial flow, which is caused by a medium flowing back in the direction of the center of the stirring element. In addition, a large number of helical and armature-like stirring elements, which are predominantly suitable for high-viscosity media, are known.

Furthermore, from the pamphlet JP 5736127 B2 a wall-moving stirring element is known, which includes stirring blades with a helical geometry and stirring blades near the bottom. The pamphlet U.S. 2011/0261643 A1 discloses a non-wall impeller device according to the preamble of claim 1.

The object of the invention is in particular to provide a generic device with improved stirring properties. The object is achieved according to the invention by the features of claim 1, while advantageous refinements and developments of the invention can be found in the dependent claims.

Advantages of the Invention

The invention is based on a stirring element device, in particular a stirring element device that does not penetrate the wall, in particular for mixing low-viscosity materials to medium-viscosity media, preferably for polymerization processes, with at least one agitator shaft and with at least one external agitator blade held on the agitator shaft, which is arm-shaped in at least one section.

According to the invention, the agitator device has at least one internal agitator blade which, together with the external agitator blade, forms at least one blade-like conveying unit which is provided at least for conveying a medium in at least one direction parallel to the agitator shaft and in particular in at least one further direction perpendicular to the agitator shaft.

According to the invention, the external stirring blade has at least one further section adjoining the arm-shaped section, in which the external stirring blade is at least largely wider than in the arm-shaped section.

As a result, advantageously improved stirring properties can be achieved. Improved mixing of a medium can be achieved particularly advantageously in at least one operating state of the stirring element device. A reduced mixing time can advantageously be achieved. In addition, a dependency of the mixing time on a viscosity can advantageously be reduced. In particular, an advantageous suspension, in particular of solid fractions of the medium, and/or in particular an improved emulsion and/or dispersion of the medium can be made possible. In particular, properties of the suspension, the emulsion and/or the dispersion can be manipulated in a targeted manner. At least one flow of the medium in a direction parallel and perpendicular to the agitator shaft can be achieved particularly advantageously. In particular, a proportion of the flow in a vertical direction can be advantageously influenced. In particular, a flexible stirring element device can be provided which can be operated as an axial and/or radial stirring element device. In addition an improved heat exchange between the medium and heating and/or cooling elements can advantageously be achieved.

A “stirring element device” is to be understood in particular as a part, in particular a functional component, in particular a structural and/or functional component, of a stirring element, for example a mixer and/or a stirring system, in particular for low-viscosity to medium-viscosity media. In particular, the stirring element device can encompass the entire stirring device. The stirring element device is advantageously designed as a component part of a stirring element or as a stirring element. The stirring element device is particularly advantageously intended to be rotated about an axis of rotation, in particular during stirring and/or mixing. When viewed along a stirring shaft of the stirring element device, the stirring element device is preferably designed point-symmetrically, in particular with respect to a longitudinal extension of the stirring element device. In an assembled state, the agitator shaft advantageously runs parallel to a vertical direction, preferably in the direction of an acting gravity force, in particular in a normal operating state of the agitator, the vertical direction preferably running perpendicular to a substrate.

The fact that a component is “arm-shaped” is to be understood here in particular as meaning that the component is elongate, with the component having a length, in particular a curved and/or angled length, which is in particular at least a factor of 2 greater than a Longitudinal extension is at least substantially perpendicular transverse extension.

A “non-wall-penetrating stirring element device” is to be understood here in particular as a stirring element device in which a ratio between a maximum diameter of the stirring element device and an inner diameter of a container which is intended for use with the stirring element device is greater than 1.05.

A “low-viscosity to medium-viscosity medium” is to be understood here in particular as meaning a medium whose dynamic viscosity is below a reference value of 50 Pas at a reference temperature of 20°C.

A “conveyor unit” is to be understood in particular as a particularly mechanical unit which, in at least one operating state, conveys, moves and/or mixes a medium, particularly a fluid and/or a solid, in at least one direction. In particular, the delivery unit can generate a flow, in particular within a container, in at least one operating state. A "shovel-like conveying unit" is to be understood here in particular as a conveying unit which has a surface which consists of a plurality of, in particular separate, closed partial regions which are arranged at an angle to one another and which partially delimit a volume. The surface can in particular have at least one opening and/or a gap.

The expression "at least a large part" is to be understood in particular as at least 55%, advantageously at least 65%, preferably at least 75%, particularly preferably at least 85% and particularly advantageously at least 95%. In particular, the external stirring blade has an average width which is preferably greater than 25%, particularly preferably greater than 40% and less than 50% of a largest diameter of the stirring element device when viewed at least along the agitator shaft, with the average width being in particular a largest average extent of the External stirring blade is to be understood perpendicularly to the stirring axis in at least one operating position in which the stirring element device can perform at least one function in an operational and assembled state. In particular, the further section is arranged in a lower area of the stirring element device with respect to at least one operating position. The further section preferably has an average width which exceeds an average width of the section by at least a factor of 2.

According to the invention, the inner stirring blade forms a shovel-like conveying unit together with the further section of the outer stirring blade. The internal stirring blade and the further section are in particular arranged at an angle to one another and together form a contact surface of the conveyor unit for energy input into the medium. This allows an optimized energy input and an advantageous mixing of the medium. In addition, a structurally simple design of the shovel-like conveyor unit can be achieved as a result. In addition, it is proposed that the internal stirring blade lies at least to a large extent, in particular completely, in an internal stirring blade plane and is in particular designed like a plate. The plane of the inner agitator blade can in particular be aligned at least essentially parallel to an axis of rotation of the agitator shaft. The axis of rotation is advantageously in the plane of the internal stirring blade. In this context, “at least essentially” is to be understood in particular as meaning that a deviation from a specified value deviates in particular by less than 25%, preferably less than 10% and particularly preferably less than 5% of the specified value. Preferably, a percentage difference between an average width of the internal stirring blade and an average height of the internal stirring blade is less than 50%. Preferably, the inner stirring blade is formed separately from the outer stirring blade. In particular, the inner stirring blade and/or the outer stirring blade is cut out or punched out of the plate-like workpiece and, in particular, subsequently processed by grinding them, for example, and rounding off their edges. A cost reduction and/or a time reduction in a manufacturing process can be achieved as a result. The stirring element device preferably has an internal stirring blade hub which is preferably connected in one piece to the internal stirring blade. "In one piece" is to be understood in particular as being at least cohesively connected, for example by a welding process, an adhesive process, an injection molding process and/or another process that appears sensible to the person skilled in the art, and/or advantageously formed in one piece, such as by a Manufacture from a single source and/or by being manufactured in a one-component or multi-component injection molding process and advantageously from a single blank. The outer agitator blade hub can be fastened to the agitator shaft in particular by means of a material connection, preferably by means of a positive and/or non-positive connection. In particular, the outer agitator blade hub and/or the inner agitator blade hub is at least largely and in particular completely made of a metal, for example steel and/or stainless steel and/or any other metal such as aluminum and/or titanium and/or an alloy. However, it is also conceivable for the outer agitator blade hub and/or the inner agitator blade hub to be made at least partially from a plastic. As a result, a safe and/or in particular a robust construction can advantageously be achieved.

In particular, a normal of the plane of the internal stirring blade is aligned perpendicularly to the axis of rotation of the stirring element device in the assembled state, so that the internal stirring blade preferably brings about a radial flow component. The internal stirring blade preferably has a trapezoidal internal stirring blade outer contour, with a bottom side of the internal stirring blade being wider than a top side when viewed at least perpendicularly to the stirring shaft. The underside and the upper side are preferably aligned parallel to one another and perpendicular to the agitator shaft. The internal stirring blade outer contour has in particular at least one right angle and at least one acute internal stirring blade angle. The internal stirring blade is preferably designed in one piece. “In one piece” is to be understood in particular as being formed in one piece. This one piece is preferably produced from a single blank, a mass and/or a cast, particularly preferably in an injection molding process, in particular a single-component and/or multi-component injection molding process. Advantageously, one-piece should also be understood to mean one-piece. It is also conceivable for the internal stirring blade to have a split design, with the internal stirring blade being divided into a number of segments which can each be fastened to the stirring shaft by means of a segment hub, so that the segments are assembled in at least one assembled state form the internal stirring blade. In this way, in particular, inexpensive production and/or simple maintenance can be made possible. Furthermore, a simple and flexible installation can be realized as a result. In addition, in particular an advantageous radial flow component can be generated.

In an advantageous embodiment of the invention, it is proposed that the external stirring blade lies at least to a large extent, in particular completely, in an external stirring blade plane. The external stirring blade preferably has a one-piece design. In particular, the external stirring blade can also have a split design, which means that assembly can be achieved with reduced effort. In particular, the plane of the outer agitator blade is oriented at an angle to the agitator shaft, which preferably creates a minimal angle of attack between the plane of the outer agitator blade and a straight line extending perpendicularly from the agitator shaft, with the angle of attack particularly preferably being at least essentially the same as at least one acute angle of the inner agitator blade. In particular, the angle of attack is more than 0° and less than 90°. The angle of incidence is preferably 50° and 70°. The angle of attack is particularly preferably 60°. In particular, the plane of the outer stirring blade and the plane of the inner stirring blade enclose a right angle. In particular, the outer stirring blade and the inner stirring blade each describe a largest circle during a full revolution around the stirring axis in at least one operating state when viewed along the stirring shaft, the circles being concentric and in particular having radii of different sizes. The agitator element device preferably has at least one external agitator blade hub, it being possible for the external agitator blade hub to be fastened to the agitator shaft by means of a material connection, preferably by means of a positive and/or non-positive connection. In this way, a cost-effective and procedurally flexible production and/or simple maintenance of the external stirring blade can be made possible.

The stirring element device, in particular the internal stirring blade and/or the external stirring blade, is preferably made at least to a large extent and in particular completely from a metal, for example from steel and/or stainless steel and/or any other metal such as aluminum and/or titanium and/or an alloy. However, it is also conceivable for the stirring element device to be made at least partially from a plastic. Furthermore, it is conceivable that individual components of the stirring element device consist of different materials.

The blade-like conveyor unit has at least one passage gap, which is arranged between the outer stirring blade and the inner stirring blade and is at least partially delimited by them, so that the passage gap has two opposing, parallel delimitations. The passage gap is provided in particular for excluding part of a medium to be mixed from being conveyed in a radial direction and in particular for generating a turbulent flow component. In this way, advantageous mixing properties can be achieved. In addition, a starting torque of the stirring element device can be reduced as a result.

In addition, it is proposed that at least one extension of the passage gap is adjustable, with "extension" being understood in particular as a smallest distance between the outer stirring blade and the inner stirring blade along the passage gap. The positioning of the inner agitator blade on the agitator shaft and of the outer agitator blade can be variably adjusted in particular with respect to one another, as a result of which the extent of the passage gap is variable. The extent of the passage gap can be adjusted in particular by displacing the inner stirring blade relative to the outer stirring blade along the stirring shaft and/or rotating the inner stirring blade relative to the outer stirring blade about the stirring axis. A minimum, in particular a vanishingly small, extension of the passage gap can be realized by shifting the inner stirring blade relative to the outer stirring blade along the stirring shaft when the outer stirring blade and the inner stirring blade are in a position in which the outer stirring blade plane and the inner stirring blade plane intersect at a right angle. By a shift of the inner agitator blade relative to the outer agitator blade along the agitator shaft, in particular a minimum extension of the passage gap between a minimum, in particular a vanishingly small extension and a maximum extension, which is caused by a respective design of the outer agitator blade and the inner agitator blade, can be adjusted. In this way, in particular, a geometry of the blade-like conveyor unit can be changed and adapted to different properties and properties of the medium, for example a density, a viscosity, an aggregate state of a disperse phase and/or a dispersion medium. In this way, advantageous stirring, mixing and/or dispersing properties can be achieved. In this way, it is particularly advantageous to be able to adjust a ratio of a flow parallel to the agitator shaft to a flow perpendicular to the agitator shaft.

It is also proposed that the inner stirring blade has at least one inner stirring blade normal and the outer stirring blade has at least one outer stirring blade normal, the inner stirring blade normal and the outer stirring blade normal enclosing a minimum normal angle greater than 0° and at most 90°. In particular, the inner stirring blade normal corresponds to at least one normal vector of the inner stirring blade plane and the outer stirring blade normal to at least one further normal vector of the outer stirring blade plane. In particular, the angle of attack enclosed by the plane of the external stirring blade with the straight line extending perpendicularly from the axis of stirring is linked to the normal angle by a relationship: normal angle=(90° angle of attack). In this way, in particular, a shape that is advantageous in terms of flow technology for the delivery unit can be implemented.

In order to advantageously be able to achieve a high level of variability when adapting a shape of the conveyor unit, it is proposed that the minimum normal angle be adjustable. Adjustment of the normal angle can be achieved by rotation of the inner agitator blade and/or the outer agitator blade around the agitator shaft which the inner stirring blade and the outer stirring blade are arranged by means of the inner stirring blade hub and/or the outer stirring blade hub.

In addition, it is proposed that the inner stirring blade can be fastened to the stirring shaft in different angular positions relative to the outer stirring blade. In particular, the internal stirring blade is attached to the internal stirring blade hub by means of a non-destructively detachable connection, for example by means of a screw, pin, bolt and/or by means of a shaft-hub connection or another positive and/or non-positive connection known to the person skilled in the art attached to the agitator shaft. As a result, the normal angle can advantageously be flexibly adjusted.

Furthermore, it is proposed that the stirring element device comprises at least one bar, via which the external stirring blade is connected to the stirring shaft. The strut preferably connects the external agitator blade to the external agitator blade hub, it being possible for the external agitator blade hub and thus the external agitator blade to be fastened to the agitator shaft. Advantageously, the main extension direction of the bar runs along a straight line perpendicular to the agitator shaft. However, an angled course of the main extension direction of the spar is also conceivable. A "main extension direction" of an object is to be understood in particular as a direction which runs parallel to a longest edge of a smallest geometric cuboid which just about completely encloses the object. The spar preferably has a circular cross-section, although other cross-sectional shapes are also conceivable. The agitator device preferably has two bars which connect the external agitator blade at different points, in particular via the external agitator blade hub, preferably on an upper external agitator blade side facing the agitator shaft and on a lower external agitator blade side facing the agitator shaft on the agitator shaft. In particular, the outer stirring blade hub with the spar and the outer stirring blade with the spar are integrally connected to one another. It is also conceivable that one of two different numbers of bars connects the external stirring blade to the stirring shaft. In particular is the Holm formed at least to a large extent and in particular completely from a metal, for example steel and / or stainless steel and / or any other metal such as aluminum and / or titanium and / or an alloy. However, it is also conceivable that the spar is at least partially made of a plastic. This can advantageously bring about a stable connection of the external stirring blade to the stirring shaft.

A particularly complete and effective mixing can be achieved if the stirring element device has at least one bottom stirring blade, which is arranged below the outer stirring blade and/or the inner stirring blade when viewed along the stirring shaft. In particular, the stirring element device has a bottom stirring blade hub, which is preferably connected to the bottom stirring blade by means of an integral connection, preferably by means of a weld seam. In particular, the bottom agitator blade is plate-like and lies at least to a large extent within a bottom agitator blade plane. The axis of stirring preferably lies within the plane of the bottom stirring blade. In particular, a bottom stirring blade normal, which is parallel to a normal vector of the bottom stirring blade, and the inner stirring blade normal lie in two parallel planes. In particular, the bottom stirring blade has a convex contour at least in sections when viewed perpendicularly to the stirring axis. The bottom agitating blade and/or the bottom agitating blade hub is preferably made at least in large part and in particular entirely from a metal, for example steel and/or stainless steel and/or any other metal such as aluminum and/or titanium and/or an alloy. Preferably, the outer stirring blade, the inner stirring blade and the bottom stirring blade are formed separately from each other. However, it is also conceivable that the outer stirring blade, the inner stirring blade and/or the bottom stirring blade are designed in one piece.

In an advantageous embodiment of the invention, it is proposed that the bottom agitator blade can be fastened to the agitator shaft in different angular positions relative to the outer agitator blade and in particular relative to the inner agitator blade. In particular, the base agitator blade normal and the external agitator blade normal have a first minimum angular position which is more than 0° and at most 90°. In particular, the angle of attack is related to the first angular position by a relationship: first angular position=(90°-angle of attack). In particular, the bottom blade has a second minimum angular position that includes the bottom blade normal and the inner blade normal, the second minimum angular position being between 0° and 180°. In this way, particularly advantageous mixing of the medium in terms of flow technology can be achieved.

In a preferred embodiment of the invention, it is proposed that the stirring element device has at least one additional external stirring blade, which is designed analogously to the external stirring blade. The stirring element device preferably has two external stirring blades which are mirror-symmetrically opposite one another with respect to the stirring shaft and are connected to the outer stirring blade hub by means of a respective bar. In particular, each point of one external stirring blade in each stirring plane that is perpendicular to the stirring axis can be superimposed by a rotation of 180° about the stirring axis with a corresponding point of the other external stirring blade. In particular, when N is a number of external stirring blades, an angular distance between the individual external stirring blades in each stirring plane is 360°/N. The stirring element device preferably has at least one further internal stirring blade and/or one further bottom stirring blade. The stirring element device preferably has two inner stirring blades, which are connected to the inner stirring blade hub in particular by means of a material connection, and two bottom stirring blades, which are connected to the bottom stirring blade hub by means of a material connection. In particular, the number of external stirring blades, internal stirring blades and/or bottom stirring blades can vary and each be more than 2 pieces. As a result, an efficient and needs-based configuration of the stirring element device can be achieved.

In addition, it is proposed that the external stirring blade and the further external stirring blade together form a closed, curved outer contour, in particular an ellipse, when viewed at least perpendicularly to the agitator shaft, in particular along a direction parallel to the bar. In particular, the external stirring blade and the additional external stirring blade overlap at least partially in a lower and an upper area of the outer contour, in which a connection between the respective bar and the respective external stirring blade takes place. The outer contour is preferably mirror-symmetrical with respect to the agitator shaft. It is conceivable that the outer contour has a geometric shape that deviates from the ellipse, in particular that it is not closed. In this way, advantageous aerodynamic stirring properties can be achieved.

In addition, it is proposed that the external stirring blade and the further external stirring blade together form an ellipse with a non-elliptical recess when viewed at least perpendicularly to the stirring shaft. The recess preferably has at least partially an elliptical inner contour which is delimited by the arm-shaped sections of the outer stirring blade and the further outer stirring blade. In particular, a lower area of the surface enclosed by the outer contour is closed, in particular to about one third. In this way, in particular, optimized mixing properties can be achieved.

Furthermore, a stirring element with at least one stirring element device is proposed. In particular, the stirring element device has a diameter of at least 0.2 meters, preferably at least 0.5 meters, particularly preferably at least 1 meter.

Furthermore, a stirring system with at least one container and with at least one stirring element arranged in the container is proposed. In particular is the stirring system is intended for industrial applications, in particular for polymerisation processes, preferably in a polymerisation reactor. In particular, the container has a volume of at least 10 liters, preferably at least 100 liters, particularly preferably at least 500 liters.

The stirring element device according to the invention should not be limited to the application and embodiment described above. In particular, the stirring element device according to the invention can have a number of individual elements, components and units that differs from a number specified here in order to fulfill a function described herein.

drawings

Further advantages result from the following description of the drawing. In the drawings an embodiment of the invention is shown. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into further meaningful combinations.

Fig. 1

einen Teil eines Rührorgans mit einer Rührorganvorrichtung in einer perspektivischen Seitenansicht,

Fig. 2

jeweils mittels Holmen der Rührorganvorrichtung mit Außenrührblattnaben der Rührorganvorrichtung verbundene Außenrührblatt der Rührorganvorrichtung und ein weiteres Außenrührblatt der Rührorganvorrichtung in einer perspektivischen Seitenansicht,

Fig. 3

das Außenrührblatt und das weitere Außenrührblatt in einer Seitenansicht quer zu einer Holm-Nabe-Verbindung der Rührorganvorrichtung,

Fig. 4

das Außenrührblatt und das weitere Außenrührblatt in einer Seitenansicht entlang der Holm-Nabe Verbindung,

Fig. 5

ein Innenrührblatt der Rührorganvorrichtung und ein weiteres Innenrührblatt der Rührorganvorrichtung an einer Innenrührblattnabe der Rührorganvorrichtung, befestigt in einer perspektivischen Seitenansicht,

Fig. 6

ein Bodenrührblatt der Rührorganvorrichtung und ein weiteres Bodenrührblatt der Rührorganvorrichtung an einer Bodenrührblattnabe der Rührorganvorrichtung, befestigt in einer perspektivischen Seitenansicht und

Fig. 7

ein Rührsystem mit dem in einem Behälter angeordneten Rührorgan.

Show it:

1

part of a stirring element with a stirring element device in a perspective side view,

2

external stirring blade of the stirring element device connected by means of bars of the stirring element device to external stirring blade hubs of the stirring element device and another external stirring blade of the stirring element device in a perspective side view,

3

the external stirring blade and the further external stirring blade in a side view transverse to a spar-hub connection of the stirring element device,

4

the external agitator blade and the other external agitator blade in a side view along the spar-hub connection,

figure 5

an inner stirring blade of the stirring organ device and another inner stirring blade of the stirring organ device attached to an inner stirring blade hub of the stirring organ device, in a perspective side view,

6

a bottom agitating blade of the impeller device and another bottom agitating blade of the impeller device attached to a bottom agitating blade hub of the impeller device in a perspective side view and

7

a stirring system with the stirring element arranged in a container.

Description of the embodiment

Various structural units and/or components are present in multiples in the exemplary embodiment described below. Components and/or structural units of similar design, which are provided with the same reference symbols in the drawings, are described only once in the following description of the drawings for the sake of simplicity.

1 shows part of a stirring element 46 with at least one stirring element device 10 in a perspective side view. The stirring element device 10 is designed as a stirring element device 10 that does not penetrate the wall. The stirring element device 10 is intended in particular for mixing low-viscosity to medium-viscosity media. The stirring element device 10 has a stirring shaft 12 . In at least one operating state, the agitator shaft 12 rotates about an agitator axis 60 of the agitator element device 10. The agitator shaft 12 transmits a torque and causes elements arranged on the agitator shaft 12 to rotate. An external stirring blade 14 and another external stirring blade 40 of the stirring element device 10 are arranged on the stirring shaft 12 . The other external stirring blade 40 is designed analogously to the external stirring blade 14 .

An internal stirring blade 16 and a further internal stirring blade 48 of the stirring element device 10 are arranged on the stirring shaft 12 . The additional internal stirring blade 48 is designed analogously to the internal stirring blade 16 .

A bottom stirring blade 38 and another bottom stirring blade 50 of the stirring organ device are arranged on the stirring shaft 12 . The other bottom stirring blade 50 is designed analogously to the bottom stirring blade 38 .

The outer stirring blade 14 , the inner stirring blade 16 and the bottom stirring blade 38 are each described below, with the description also applying to the additional outer stirring blade 40 , the additional inner stirring blade 48 and the additional bottom stirring blade 50 .

The external stirring blade 14 has an arm-shaped section 18 . The external stirring blade 14 has a further section 22 . The further section 22 borders on section 18 . The external stirring blade 14 is wider in the further section 22 than in the section 18 .

The impeller device 10 has a first external impeller hub 56 . The impeller device 10 has another external impeller blade hub 58 . The stirring element device 10 has a first bar 52 . The stirring element device 10 has a second bar 54 . The external stirring blade 14 is connected to the first external stirring blade hub 56 in section 18 by means of the first spar 52 of the stirring element device 10 ( 2 ). The outer stirring blade 14 is connected to the further outer stirring blade hub 58 in the further section 22 by means of the second bar 54 . The first outer agitator blade hub 56 and the further outer agitator blade hub 58 are each fastened to the agitator shaft 12 by means of a screw connection. Other connections of the first outer stirring blade hub 56 and the second outer stirring blade hub 58, for example a clamp connection, are also conceivable. The first bar 52 and the second bar 54 point in opposite directions when viewed along the agitator shaft 12 starting from the agitator shaft 12 , so that the first bar 52 and the second bar 54 enclose an angle of 180°. The first bar 52 and the second bar 54 are each aligned perpendicular to the agitator shaft 12 .

The stirring element device 10 has an outer stirring blade plane 26 . The external stirring blade 14 lies completely in the external stirring blade plane 26 ( 2 ). The arm-shaped section 18 has a constant, smallest section thickness 104 lying in the plane 26 of the outer stirring blade. The section thickness 104 is preferably between 5% of a diameter 102 of the stirring element device 10 and less than 50% of the diameter 102, particularly preferably 15% of the diameter 102. When viewed perpendicularly to the agitator shaft 12 and to a main direction of extension of the bar 52, the external agitator blade 14 and the other external stirring blade 40 has an X-shaped contour. A "main extension direction" of an object is to be understood in particular as a direction which runs parallel to a longest edge of a smallest geometric cuboid which just about completely encloses the object
The internal stirring blade 16 has at least one internal stirring blade normal 32 ( 1 ). The external stirring blade 14 has at least one external stirring blade normal 34 . The inner stirring blade normal 32 and the outer stirring blade normal 34 enclose a minimum normal angle 36 of 90°. The normal angle 36 can be greater than 0° and at most 90°.

The normal angle 36 is adjustable. The normal angle 36 can be adjusted, for example, by rotating the internal stirring blade 16 about the stirring axis 60 . The normal angle 36 depends on an inclination of the external stirring blade 14 with respect to a plane perpendicular to the stirring axis 60 .

The external stirring blade 14 has an external stirring blade length 108 ( 3 ). The external agitator blade 14 has an angle of attack 62 with respect to a plane aligned perpendicular to the agitator shaft 12 . The angle of attack 62 is preferably 60°. The normal angle 36 can be determined from the relationship normal angle 36=(90°- angle of incidence 62). The impeller device 10 has a diameter 102 ( 3 ). The diameter is 102 with the angle of attack 62 linked by a relationship cos(angle of attack 62)=diameter 102 / length of external stirring blade 108.

figure 5 shows the internal stirring blade 16 . The stirring element device 10 has an internal stirring blade plane 24 . The internal stirring blade 16 lies completely in the internal stirring blade plane 24. The internal stirring blade 16 is plate-like. The impeller assembly 10 includes an internal impeller blade hub 66 . The internal stirring blade 16 and the further internal stirring blade 48 are arranged on the internal stirring blade hub 66 . The inner stirring blade 16 and the further inner stirring blade 48 are each arranged on the inner stirring blade hub 66 by means of a welded connection. The internal agitator blade hub 66 is attached to the agitator shaft 12 by a bolted connection. Other connections of the internal stirring blade hub 56, for example a clamp connection, are also conceivable. An angular distance between the internal stirring blade 16 and the further internal stirring blade 48 is 180°. If there are several internal stirring blades, the individual internal stirring blades are arranged at an equidistant angular distance. The angular distance can be determined according to the relationship 360°/number of internal stirring blades.

Viewed along the internal stirring blade normal 32, the internal stirring blade 16 has a trapezoidal contour 68. The trapezoidal contour 68 has sides 96 , 98 arranged perpendicular to one another, with one of the sides 96 running parallel to the agitator shaft 12 and the other side 98 running perpendicular to the agitator shaft 12 . The trapezoidal contour 68 has a further side 70 which runs parallel to the plane 26 of the outer stirring blade.

The inner stirring blade 16 together with the further section 22 of the outer stirring blade 14 forms a shovel-like conveying unit 20 of the stirring element device 10 . The conveying unit 20 is provided for conveying a medium in a direction parallel to the agitator shaft 12 and in a further direction perpendicular to the agitator shaft 12 . This allows a radial flow of the medium, wherein the radial flow is directed in particular perpendicular to the agitator shaft 12, and a axial flow of the medium, the axial flow being directed in particular parallel to the agitator shaft 12, arise.

The shovel-like conveyor unit 20 has a passage gap 28 ( 1 ). The passage gap 28 is delimited by the further side 70 of the trapezoidal contour 68 of the inner stirring blade 16 and by the plane 26 of the outer stirring blade.

An extension 30 of the passage gap 28 is adjustable. For example, the internal stirring blade 16 can be displaced along the stirring shaft 12 . In addition, the internal stirring blade 16 can be rotatable about the stirring shaft 12 . The inner stirring blade 16 can be fastened to the stirring shaft 12 in different angular positions relative to the outer stirring blade 14 .

The passage gap 28 can either be completely closed or opened to the maximum extent. The passage gap 28 is maximally large when the internal stirring blade 16 is adjusted perpendicularly to the main direction of extension of the bar 52 .

The bottom agitator blade 38 is arranged below the outer agitator blade 14 and/or the inner agitator blade 16 when viewed along the agitator shaft 12 ( 1 ).

The agitator device 10 has a bottom agitator blade plane 64 . The bottom agitator blade 38 lies completely in the bottom agitator blade plane 64 ( 6 ). The bottom stirring blade 38 is plate-like. In a viewing direction parallel to a floor agitator blade normal 74 of the floor agitator blade 38, the floor agitator blade 38 has a maximum extension 106 parallel to the agitator shaft 12 between 5% of the diameter 102 and less than 50% of the diameter 102, particularly preferably 15% of the diameter 102. The impeller assembly 10 includes a bottom agitator blade hub 72 . The bottom stirring blade 38 and the further bottom stirring blade 50 are arranged on the bottom stirring blade hub 72 . The bottom stirring blade 38 and the further bottom stirring blade 50 are each arranged on the bottom stirring blade hub 72 by means of a welded connection. The bottom blade hub 72 is attached to the agitator shaft 12 by a bolted connection. There are also other connections of the bottom stirring blade hub 72, for example a clamp connection, imaginable. An angular distance between the bottom stirring blade 38 and the further bottom stirring blade 50 is 180°. If there are several soil stirring blades, the individual soil stirring blades are arranged at an equidistant angular distance. The angular distance can be determined according to the relationship 360°/number of soil stirring blades.

Viewed along the bottom blade normal 74 , the bottom blade 38 has a contour 76 that includes a convex side 78 . The stirring element 46 can be arranged in a container 80 . The convex side 78 conforms to a bottom 82 of the container 80 .

The bottom stirring blade 38 can be fastened to the stirring shaft 12 in different angular positions relative to the outer stirring blade 14 . The bottom stirring blade 38 can be fastened in different angular positions in relation to the inner stirring blade 16 . The angular settings can be adjusted by rotating the bottom agitator blade hub 72 about the agitator shaft 12 .

The conveying unit 20 and all further conveying units, which are formed by further sections and further internal stirring blades, always point in the same direction of rotation during a rotary movement of the stirring element device 10 about the stirring axis 60 in at least one operating state.

figure 4 shows the external stirring blade 14 and the additional external stirring blade 40 viewed perpendicularly to the agitator shaft 12. The external stirring blade 14 and the additional external stirring blade 40 together form a closed curved outer contour 42. The curved outer contour 42 is designed as an ellipse 84. In an upper and a lower vertex area 86, 88 of the ellipse 84, the outer stirring blade 14 and the further outer stirring blade 40 overlap when viewed perpendicularly to the agitator shaft 12. In areas in which, when viewed perpendicularly to the agitator shaft 12, the outer stirring blade 14 and the further outer stirring blade 40 overlap, there are connecting points of the bars 52, 54 with the external stirring blade 14 and the further external stirring blade 40. A lower third of the area 90 enclosed by an ellipse 84 is closed.

The outer stirring blade 14 and the further outer stirring blade 14 together form the ellipse 84 with a non-elliptical recess 44 when viewed perpendicularly to the stirring shaft 12. The recess 44 is defined in upper and lateral areas by respective arm-shaped sections 18, 92 of the outer stirring blade 14 and the further External stirring blade 40 limited. The recess 44 is delimited in a lower region of the recess 44 by respective further sections 22 , 94 of the external stirring blade 14 and of the further external stirring blade 40 .

figure 7 12 shows a stirring system 100 with the stirring element 46 arranged in the container 80. The container 80 is provided for receiving a medium to be processed by the stirring element 46. The container 80 has a container diameter 110 . The container diameter 110 is, in particular, at least a factor of 1.05 larger than the diameter 102 of the stirring element device 10. The stirring element 46 has at least one motor 112. The motor 112 is connected in particular to the agitator shaft 12 . The motor 112 is intended to transmit a torque to the stirring element 46 in at least one operating state. In at least one operating state, the stirring element 46 generates a first flow, which is directed perpendicularly to the stirring shaft 12 and a second flow, which is directed at least essentially parallel to the stirring shaft 12 . The first flow is essentially due to the internal stirring blade 16 . The second flow is essentially due to the external stirring blade 14 . The proportion of the first flow in an overall flow is determined by the extent 30 of the passage gap 28 .

Reference sign

10

impeller device

12

agitator shaft

14

external stirring blade

16

internal stirring blade

18

Section

20

conveyor unit

22

Section

24

inner blade level

26

outside agitator blade level

28

passage gap

30

extent

32

Internal stirring blade standards

34

External blade standards

36

normal angle

38

soil stirring blade

40

external stirring blade

42

outer contour

44

recess

46

agitator

48

internal stirring blade

50

soil stirring blade

52

spar

54

spar

56

external blade hub

58

external blade hub

60

stirring axis

62

angle of attack

64

bottom agitator blade level

66

internal blade hub

68

contour

70

Page

72

bottom blade hub

74

soil agitator blade normal

76

contour

78

convex side

80

container

82

Floor

84

ellipse

86

vertex area

88

vertex area

90

Surface

92

Section

94

Section

96

Page

98

Page

100

stirring system

102

diameter

104

section thickness

106

expansion

108

outer blade length

110

container diameter

112

engine

Claims (15)

1. Non-close-clearance agitator device (10) for mixing low-viscosity to medium-viscosity media,

   with at least one agitation shaft (12)

   and with at least one outer agitation blade (14) held on the agitation shaft (12)

   and realized in at least one section (18) in an arm shape,

   and with at least one inner agitation blade (16), which forms together with the outer agitation blade (14) at least one vane-like conveying unit (20) that is configured at least for conveying a medium in at least one direction parallel to the agitation shaft (12),

   the outer stirring blade (14) having at least one further section (22) adjoining the section (18) formed in an arm shape, in which the outer agitation blade (14) is wider than in the section (18) formed in an arm shape,

   wherein the inner agitation blade (16) forms the vane-like conveying unit (20) together with the further section (22) of the outer agitation blade (14),

   characterised in that the vane-like conveying unit (20) has at least one pass-through gap (28) which is arranged between the outer agitation blade (14) and the inner agitation blade (16) and is at least partially delimited by the outer agitation blade (14) and the inner agitation blade (16), such that the pass-through gap (28) has two opposite-situated parallel delimitations.
2. Non-close-clearance agitator device (10) according to one of the preceding claims,
   characterised in that the inner agitation blade (16) is situated at least to a large extent in an inner agitation blade plane (24).
3. Non-close-clearance agitator device (10) according to one of the preceding claims,
   characterised in that the outer agitation blade (14) is situated at least to a large extent in an outer agitation blade plane (26).
4. Non-close-clearance agitator device (10) according to one of the preceding claims,
   characterised in that at least one extension (30) of the pass-through gap (28) is adjustable.
5. Non-close-clearance agitator device (10) according to one of the preceding claims,

   characterised in that the inner agitation blade (16) comprises at least one inner agitation blade normal (32) and the outer agitation blade (14) comprises at least one outer agitation blade normal (34),

   the inner agitation blade normal (32) and the outer agitation blade normal (34) including a minimum normal angle (36) that is larger than 0° and maximally 90°.
6. Non-close-clearance agitator device (10) according to claim 5,
   characterised in that the minimum normal angle (36) is adjustable.
7. Non-close-clearance agitator device (10) according to one of the preceding claims,
   characterised in that the inner agitation blade (16) is fixable to the agitation shaft (12) in different angular positions with respect to the outer agitation blade (14).
8. Non-close-clearance agitator device (10) according to one of the preceding claims,
   characterised by at least one bar (52, 54) via which the outer agitation blade (14) is connected to the agitation shaft (12).
9. Non-close-clearance agitator device (10) according to one of the preceding claims,
   characterised by at least one bottom agitation blade (38) which, viewed along the agitation shaft (12), is arranged below the outer agitation blade (14) and/or the inner agitation blade (16).
10. Non-close-clearance agitator device (10) according to claim 9,
    characterised in that the bottom agitation blade (38) is fixable to the agitation shaft (12) in different angular positions with respect to the outer agitation blade (14).
11. Non-close-clearance agitator device (10) according to one of the preceding claims,
    characterised by at least one further outer agitation blade (40), which is realized analogously to the outer agitation blade (14).
12. Non-close-clearance agitator device (10) according to claim 11,
    characterised in that at least in a view perpendicularly to the agitation shaft (12), the outer agitation blade (14) and the further outer agitation blade (40) together form a closed curved outer contour (42).
13. Non-close-clearance agitator device (10) according to claim 11 or 12, characterised in that at least in a view perpendicularly to the agitation shaft (12), the outer agitation blade (14) and the further outer agitation blade (40) together form an ellipse (84) with a non-elliptic recess (44).
14. Agitator (46) with at least one non-close-clearance agitator device (10) according to one of the preceding claims.
15. Agitation system (100) with at least one container (80) and with at least one agitator (46) according to claim 14, which is arranged in the container (80).

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