EP2844481B1 - Mixing device, fluid system and mixing process - Google Patents

Description

The present invention relates to a mixing device for mixing a fluid in a container, in particular a fluid system, a fluid system, in particular for colors in a printing press, and a method for mixing a fluid in a container, in particular a fluid system.

Mixing devices for mixing a fluid in a container are known in principle. They are particularly in fluid systems, eg. B. for colors in a printing press used. It is, z. B. in a printing press, a rotatable stirrer provided, which ensures by means of a driven drive axle for a mixing of a fluid in the container. For this purpose, a separate drive for this stirring device is necessary. For example, when using inks in printing presses, agitation is imperative to introduce shear forces into the fluid. Especially in the case of colors which have thixotropic properties, it is only through the Incorporating the shear forces with the aid of known stirrers achieves a reduction in the viscosity. Only by reducing the viscosity can processing or pumping of the paint take place. Another reason for the need for mixing the fluid is the provision of fluid mixtures. Thus, for example, additives are provided in the fluid, in particular in the color, which should be distributed as homogeneously as possible. Such additives may be waxes for improved surface texture, color corrections in the form of pigment-containing makeup fluids or solvents. The more homogeneous the distribution in the fluid takes place in the container, the more homogeneous will be the print image in a printing machine over the course of a printing process.

It is disadvantageous in known mixing devices that a high design effort is necessary to ensure thorough mixing. So separate stirrers or agitators are required to achieve the mixing. This requires additional drives, z. B. in the form of an electric motor. Also, a rotary bearing must be provided for the corresponding drive shaft of a stirrer. Since in particular for containers for fluid systems of a printing machine an easy cleanability should be given, such rotating elements make a high cleaning effort. In addition, a drive for such a stirrer or the agitator itself requires additional space, which lost for other uses in a corresponding machine goes. Last but not least, the provision of an additional drive and an additional agitator also increases the cost of manufacturing such a fluid system or such a mixing device.

US Pat. No. 6,109,788 discloses a mixing device according to the preamble of claim 1. It is therefore an object of the present invention to at least partially overcome the disadvantages described above. In particular, it is an object of the present invention to provide a mixing device for mixing a fluid in a container, a fluid system and a method for mixing a fluid in a container, which in a cost effective and simple manner mixing of the fluid in the container allow as homogeneous as possible.

The above object is achieved by a mixing device having the features of claim 1, a fluid system having the features of claim 11 and a method having the features of claim 14. Further features and details of the invention result from the subclaims, the description and the drawings. In this case, features and details that are described in connection with the mixing device according to the invention apply, of course, also in connection with the inventive method and the fluid system according to the invention and in each case vice versa, so that with respect to the disclosure of the individual aspects of the invention is always reciprocally referred to or become can.

A mixing device according to the invention according to claim 1 is used for mixing a fluid in a container, in particular a fluid system. The mixing device has a fluid supply and at least one outlet arm with an outlet opening. In this case, the fluid supply is connected in a fluid-communicating manner with the at least one outlet arm. A mixing device according to the invention is characterized in that the outlet opening is aligned for an outlet of the fluid in an outlet direction in order to set the fluid in the container at least in sections in rotation. The rotation of the fluid in the container is designed as a rotational movement of individual fluid volumes in the container. In particular, it is a forced convection triggered by the discharged fluid. In this case, there is a mixing or swirling of the individual fluid volumes with each other, without rotating components are necessary. A mixing device according to the invention preferably makes use of the fact that, given appropriate use for a fluid system, recirculation or circulation for the fluid is frequently provided. If the mixing device z. B. used for the fluid system of a printing press, so there is a suction of the fluid from this designed as a storage container container to the printing press. At the same time, a return transport of excess fluid back into the container takes place. This creates a circulation during operation of the fluid system. This circuit is now additionally used to ensure the mixing of the fluid. It is dispensed with additional components such as agitators. According to the invention a fluid supply is provided which of z. B. a pumping device of a circuit for the fluid, the fluid composition gets supplied. The fluid supply is z. B. tubular or designed as a pipeline. In the free cross section in the interior of the fluid supply, the fluid can flow in the direction of the outlet arms or in the direction of the outlet openings.

At least one outlet arm is provided, which is connected in fluid communication with the fluid supply. This means that the fluid from the fluid supply through the Auslassarm can get to the outlet or pumped. In this case, the outlet arm preferably extends at least in sections radially or substantially radially away from the fluid supply. The fluid supply is in particular arranged vertically in the depth direction of the container, so that delivery of the fluid to the container bottom is carried out. The Auslassarm thus preferably serves to promote transverse to the depth direction of the container, so that it is conveyed to the container to. The outlet opening with an outlet direction in accordance with the invention serves to set the fluid in the container at least in sections in rotation.

In a mixing device according to the invention can be dispensed with additional agitators, since the fluid itself provides in the container for its own mixing. This is due to the fact that it is rotated in accordance with the invention. During the rotation of a fluid, the same mixes. In particular, the rotation is a forced convection of the fluid in the container, which is pushed or ejected by discharged fluid from the outlet openings of the outlet arms.

The rotation of the fluid in the container is substantially or exactly symmetrical, so that an at least partially continuous and uniform mixing of the fluid takes place in the container.

A mixing device according to the invention can be used both in continuous operation in a printing machine of a fluid system, as well as for the preconditioning before the use of the fluid system in the form of a printing press. It is crucial that a relative movement of individual volume elements of the fluid in the container through the outlet of the fluid with an outlet direction according to the invention from the outlet openings is generated.

The outlet direction is preferably directed at least in sections in the circumferential direction or substantially in the circumferential direction of the container. This is particularly related to substantially cylindrical container. Thus, in a cylindrical container, the circumferential direction is arranged along tangents to a circular line. Radially inwardly offset is a corresponding inner circular line, in whose direction at least partially the outlet direction of the fluid is directed to the outlet opening. Accordingly takes place Preferably, a tangential outlet along this inner circumferential line, so that a rotation of the fluid is formed in the container, which extends substantially along or parallel to the outer wall of the cylindrical container.

In a mixing device according to the invention, the at least one outlet arm or in particular the outlet opening of the at least one outlet arm is arranged below the fluid level within the container. If it is a storage container which is slowly emptied over the course of the operation of the fluid system, the outlet opening is preferably arranged in the depth direction particularly close to the bottom of the container in order to reduce the liquid level of the fluid in the container, an inventive mode of operation of the mixing device to keep as long as possible.

As will be explained later, according to the invention, different angles can be defined in order to precisely adjust the outlet direction. In this case, in particular, it is avoided that an angle to the adjacent container wall of the container is specified for the outlet device, which lies at 90 °. Rather, this angle is preferably chosen smaller than 90 °, in particular smaller than 85 °.

In the context of the present invention, a fluid is to be understood as meaning in particular a color or a color composition. Such a color composition may be mainly liquid ingredients, but also solid ingredients such. For example, pigments. Of course, in a mixing device according to the invention, the fluid may also be a flowable solid or a fluidizable powder.

The rotation, which is generated by means of a mixing device according to the invention in the fluid in the container, in addition to the mixing and settling of solids or deposits on the bottom of the container is prevented. If the fluid is a paint or a paint composition, the formation of a sediment or a paint sludge on the ground can be avoided in this way.

It should further be pointed out that the mixing device can fulfill a second function according to the invention, namely the necessary recycling of excess fluid from a fluid system. Thus, a mixing device according to the invention by this dual function to provide mixing as a function available, without additional installations, eg. B. in the form of agitators necessary.

To ensure sufficient flow rates, eg. B. in the range of about 18 l / min to be able to ensure by the fluid supply, preferably outlet cross-sections or free flow cross sections of the outlet arms / outlet openings in the range between about 2 mm and about 10 mm, preferably in the range of about 6 mm +/- 2 mm usable.

The fluid supply and / or the at least one outlet arm are preferably rigid components in relation to one another or in relation to the container. In particular, the mixing device is designed such that it can be arranged rotationally fixed on the container.

It may be advantageous if, in a mixing device according to the invention, the at least one outlet arm extends at least in sections perpendicular or substantially perpendicular to the fluid supply. If the container as a whole is essentially cylindrical, then the outlet arm is preferably directed radially or substantially radially away from the fluid supply. Accordingly, an approach to a circumferential direction, which is aligned parallel to the circumferential direction of the container, forms for the outlet direction.

In a mixing device according to the invention, the at least one outlet arm is curved at least in sections. Thus, the fluid can be guided radially outward from the fluid supply and directed there through the bend in the desired outlet direction. In particular, in the case of a fluid supply which is aligned parallel and / or coaxially with the container axis of the container, this embodiment is advantageous. The curve is along a curve. In the design with a plurality of outlet arms, all the outlet arms are curved in the same direction. Thus, a spiral formation of the outlet arms is provided, which allows a continuous pushing the rotation of the fluid in the container. At the same time, the outlet arms are preferably provided with an outer cross-section, which is as possible low impact on the surrounding flow. Preferably, the outer cross section of the individual outlet arms is round. Such a cross-section is also particularly easy to clean.

It is likewise advantageous if in a mixing device according to the invention the outlet opening is aligned for the outlet direction of the fluid with a vertical angle and / or a horizontal angle, the vertical angle and / or the horizontal angle being less than 90 °, in particular less than about 85 °. These angles are explicit angles which may allow adjustment of the outlet direction. Thus, an angle is designated by the horizontal angle, which extends substantially in a horizontal plane with respect to the container. The vertical angle is preferably an angle which extends in a plane which is formed parallel to the container axis. Thus, two angles can be provided, which have an expression of less than 90 °, so that an outlet direction exactly on the container bottom or exactly on the container wall is avoided. All other angular orientations of the outlet directions are possible according to the invention, so that a rotation of the fluid in the container is triggered. In the normal case, particularly small angles will often be used in order to be able to provide a particularly efficient generation of the rotation of the fluid in the container. Thus, vertical angle and / or horizontal angle are preferably formed in the range of less than about 60 °, preferably in a range of less than about 45 °, more preferably in a range of 0 ° to about 30 °. The vertical adjustment can cause dead spaces in the area of the bottom of the container to be better rinsed out. Depending on the orientation of the individual outlet direction, corresponding rotational changes of the fluid in the container can be carried out, so that an explicit adjustment of the fluid dynamics takes place within the container. Of course, the outlet directions of individual outlet arms can be designed differently with a plurality of outlet arms of a mixing device, so that even complex fluid flows can be generated in a defined manner.

Furthermore, it is advantageous if, in a mixing device according to the invention, at least two outlet arms each having an outlet opening are provided, wherein the outlet openings have different vertical angles, in particular with different signs to the horizontal plane. The horizontal plane is formed by a plane which extends substantially parallel to the bottom surface of the container. Thus, a vertical angle of more than 0 ° and less than 90 ° means an orientation of the respective outlet opening on the bottom surface to or from this. The introduction of fluid can cause blistering to cause foaming on the surface of the fluid in the container. In order to avoid this, an orientation of the outlet openings is provided in the downward and / or upward direction in this embodiment. Thus, an improved distribution of the fluid is achieved, whereby the foaming can be reduced or even completely avoided. The vertical angles are provided depending on the orientation of the outlet opening upwards or downwards with different signs to the horizontal plane. For the reduction of foaming, it may be advantageous if at least one outlet opening has an orientation away from the bottom surface of the container. In the case of an upward and downward orientation, the amounts of the vertical angles with different vertical angles are preferably the same or substantially the same.

It is also advantageous if, in the case of a mixing device according to the invention, all the outlet openings in the circumferential direction alternately have different signs of the vertical angle to the horizontal plane. This means that z. B. alternately always one or two outlet openings down and then in the circumferential direction one or two outlet openings are aligned upward. Thus, a particularly effective axial distribution of the introduced fluid can be achieved. Foaming on the surface of the fluid in the container is thus further reduced or even completely prevented.

It is also advantageous if in a mixing device according to the invention, the vertical angle below the horizontal plane in the range between about 2 ° and about 7 ° and / or the vertical angle above the horizontal plane in the range between about 10 ° and about 20 ° are formed , These are the amounts of the respective vertical angles. Depending on the viewing direction, the vertical angles have a positive (towards the container bottom) in one direction and a negative (away from the container bottom) in the other direction. These angular ranges represent advantageous embodiments, as on this way the reduction of foaming can be combined with the rotation of the fluid in the container.

It is also advantageous if at least two outlet arms are provided in a mixing device according to the invention, which are aligned for outlet directions of the fluid along a common circumference. Thus, the outlet directions form a circular line along which the main rotation of the fluid in the container is formed. The number of outlet arms can be z. B. at 2, 3, 4, 5, 6 or more Auslassarmen lie. These individual outlet arms can be arranged distributed uniformly or non-uniformly in the circumferential direction. The number of arms is preferably adapted to the size of the associated container, so that in smaller containers a smaller number of outlet arms and in larger containers a larger number of outlet arms can be provided. The size is to be understood mainly to the inner diameter of the container, so that at large inner diameters, a regular pushing the rotation of the fluid in the container can be carried out by a corresponding plurality of Auslassarmen and outlet openings. If a plurality of outlet arms are provided, struts between the individual arms and / or fluid supply may be used to stabilize the outlet arms and the fluid supply.

The individual arms are preferably distributed symmetrically, so that facilitated production is possible. The individual outlet arms can be produced as a standard part and then combined to form the mixing device according to the invention. The outlet arms can z. B. made of metal, in particular made of steel, and attached to the fluid supply, in particular welded.

It may also be advantageous if in a mixing device according to the invention at least two outlet arms are provided, which are distributed regularly or substantially regularly around the fluid supply. Regular distribution of the scope leads to a further reduction in production costs. In addition, in this way a particularly regular influence on the forming rotational flow of the fluid in the container takes place. Thus, in particular, a regular pushing of the fluid takes place, so that a regular and continuous rotation of the fluid in the container can be formed.

It is furthermore advantageous if, in a mixing device according to the invention, at least two outlet arms are provided, which extend at least in sections in a common plane. This also reduces the effort in the production. In particular, it is a disc-like design of the outlet arms, so that a particularly small undesirable influence in the form of flow disturbance can be achieved by the outlet arms themselves with a mixing device according to the invention.

It may also be advantageous if, in a mixing device according to the invention, the fluid supply is designed to extend in the container along or parallel to the container axis, in particular into the lower half of the container. Preferably, the extension into the lower half of the container results in that, even with a continuous decrease of the fluid level within the container, a rotation according to the invention of the fluid in the container is made possible. In particular, the extension along or parallel to the container axis causes the same time the storage of the outlet arms at the desired height in the container via the fluid supply. In particular, the rotation of the lower half of the fluid in the container results in the desired mixing occurring in the region of the suction in a pump sump in the container with regard to a viscosity distribution or thorough mixing of individual constituents of the fluid.

A further advantage is achieved in that the fluid supply in the region of the connection to the at least one outlet arm has at least one additional opening in order to avoid dead spaces in this area. This at least one additional opening may be directed in any direction with respect to its outlet direction, that is to say in particular radially, tangentially or axially with respect to the orientation of the fluid supply and / or the container axis. In this way, any dead spaces possibly arising in the connection region between the at least one outlet arm and the fluid supply can be avoided or reduced with little or no movement of the fluid. For example, the fluid supply at its lower end a conclusion, preferably in the form of a lid, which is equipped with this at least one additional opening. An embodiment of the at least one additional opening above the connection to the at least one outlet arm is also conceivable in the context of the present invention, so that above the connection area, the danger of a developing dead space can be avoided. In other words, an additional turbulence of the fluid can take place in this way, as a result of which the quality of the mixing of the fluid in the manner according to the invention is even further improved.

Another object of the present invention is a fluid system according to claim 11, in particular for paints in a printing press, comprising at least one container for the storage of a fluid. Further, a flow pump and a return pump for the delivery of the fluid are provided. Also provided are a fluid receiver, in particular a pressure roller, and a fluid tub for providing and / or collecting the fluid for and / or from the fluid receiver. In this case, the feed pump is designed for conveying the fluid from the container to the fluid receiver and the return pump is designed for conveying the fluid from the fluid trough back into the container. A fluid system according to the invention is characterized in that a mixing device with the features according to the present invention is provided, wherein the fluid supply of the mixing device is fluidly communicating with the pressure side of the return pump. A fluid system according to the invention can, for. B. are used for a printing press, and serves to maintain a color cycle upright. So is stored in the container color, which via the flow pump z. B. is conveyed to a pressure roller of the printing press. The deposited by a squeegee, excess paint is collected in a fluid tray and promoted by the return pump back into the container. This basic functionality of the color cycle is now also used according to the invention for mixing the color within the fluid. Thus, the color is conveyed in the form of a fluid through the fluid supply of the mixing device according to the invention for the formation of the rotation of the fluid in the container. The inventive design of the mixing device brings a fluid system according to the invention with the same advantages, as they have been explained in detail with respect to a mixing device according to the invention. The suction via the feed pump is preferably carried out in a sump at the bottom or in the vicinity of the bottom of the container.

Under a pressure roller in the context of the present invention is in particular a roller to understand, which is designed as a ink transfer roller. It serves to transfer the fluid in the form of a color as the last roller to the medium to be printed.

A fluid system according to the invention can be further developed such that the pressure side of the feed pump is connected in a fluid-communicating manner via a bypass to the suction side of the return pump. This bypass makes it possible, even independently of a large circuit via the fluid receiver, in particular in the form of a pressure roller, to allow thorough mixing in accordance with the invention. Thus, a preconditioning can be carried out without the entire fluid system with the fluid receiver, so the entire printing press, must be turned on. If a container is refilled, so before starting the printing process via the bypass via the flow pump and the return pump, a small circuit can be ensured, which allows a pre-mixing by forming a rotation of the fluid in the container with a mixing device according to the invention. In this case, preferably at least three valves are provided, which are arranged as a flow valve after connection to the bypass and after the flow pump, as a return valve after connection to the return pump and the bypass and as a bypass valve in the bypass.

It is also advantageous if, in a fluid system according to the invention, the outlet opening of the at least one outlet arm is arranged between approximately 20% and approximately 80% of the radial distance between the fluid supply and the surrounding wall of the container. The further outward the outlet opening of the outlet arm is arranged, the higher is the influence on the rotation of the fluid in the container, since the lever becomes larger to the axis of rotation in the container. The greater is preferably the volume flow to overcome the corresponding lever arm and the associated force for the rotation of the fluid in the container.

It may also be advantageous if in a fluid system according to the invention, the mixing device is arranged rotationally fixed to the container. This z. B. flange connections are used, as they are already known in known containers for the return of excess fluid. A mixing device according to the invention can thus also be retrofitted in an already known fluid system.

• Einbringen von Fluid aus einer Auslassöffnung wenigstens eines Auslassarmes in den Behälter mit einer Auslassrichtung, die ausgerichtet ist, um das Fluid im Behälter zumindest abschnittsweise in Rotation zu versetzen.

Another object of the present invention is a method according to claim 14 for the mixing of a fluid in a container, in particular a fluid system, with a mixing device. Such a method according to the invention has at least the following step:

• Introducing fluid from an outlet port of at least one outlet arm into the container with an outlet direction aligned to at least partially rotate the fluid in the container.

The inventive method performs the mixing of a fluid with a fluid system according to the invention. Thus, a method according to the invention brings about the same advantages as have been explained in detail with reference to a fluid system according to the invention or with reference to a mixing device according to the invention.

It is also advantageous if in a method according to the invention for pre-convection of the fluid in the container air, in particular st + oßweise, is introduced from the outlet opening of the at least one Auslassarmes in the container. If, for example, a fluid trough is provided in the fluid system, then air can be drawn in from this empty-suctioned fluid trough, wherein this air suction can be opened and closed via corresponding valves. Thus, intermittently, the air may be ejected intermittently with fluid through the outlet port of the outlet arm. As the fluid from the outlet ports abuts the rotation of the fluid in the container, the air will rise within the fluid during rotation of the fluid in the container. Ascending causes additional forced convection of volume elements within the fluid in the container in the vertical upward direction, so that an additional mixing direction is achieved. The pulsed intermittent introduction of air may preferably be between about 2 seconds and about 10 seconds.

Fig. 1

eine Ausführungsform eines erfindungsgemäßen Fluidsystems,

Fig. 2

eine weitere Ausführungsform eines erfindungsgemäßen Fluidsystems,

Fig. 3

eine Ausführungsform einer Mischvorrichtung,

Fig. 4

eine weitere Ausführungsform einer Mischvorrichtung,

Fig. 5

eine weitere Ausführungsform einer Mischvorrichtung,

Fig. 6

eine weitere Ausführungsform einer Mischvorrichtung,

Fig. 7

eine weitere Ausführungsform einer Mischvorrichtung und

Fig. 8

eine weitere Ausführungsform einer Mischvorrichtung.

The present invention will be explained in more detail with reference to the accompanying drawing figures. The terms "left", "right", "top" and "bottom" used herein refer to an alignment of the drawing figures with normally readable reference numerals. They show schematically:

Fig. 1

an embodiment of a fluid system according to the invention,

Fig. 2

a further embodiment of a fluid system according to the invention,

Fig. 3

an embodiment of a mixing device,

Fig. 4

a further embodiment of a mixing device,

Fig. 5

a further embodiment of a mixing device,

Fig. 6

a further embodiment of a mixing device,

Fig. 7

a further embodiment of a mixing device and

Fig. 8

a further embodiment of a mixing device.

In FIG. 1 A first embodiment of a fluid system 100 according to the invention is shown. This is preferably a part of a printing press. Thus, a fluid receiver 140 is provided which z. B. as a pressure roller or anilox roller of a printing machine, in particular a flexographic printing machine or a rotary printing machine, is formed. Via a feed pump 120, fluid is conveyed from a container 110, in particular a color composition, to the fluid receiver 140. Excess fluid is withdrawn from the fluid receiver 140, and collected in a fluid trough 150 via a withdrawal device in the form of a squeegee, not shown. About the return pump 130, the collected fluid from the fluid well 150 is returned to the container 110. This is the normal fluid circuit or the working cycle of the fluid.

In the fluid system 100 according to FIG. 1 is the overall training, as well as the formation of a mixing device 10 is carried out according to the invention. Thus, the mixing device 10 is provided with a fluid supply 20, which in a fluid-communicating manner with a Plurality of outlet arms 30 is connected. Each of these outlet arms 30 is provided with an outlet opening 32 having an outlet direction A (in FIG FIG. 1 not shown) to set the fluid in the container 110 in rotation. Thus, the cycle described below is possible in a fluid system 100 according to the invention.

At the beginning of a printing process, the fluid receiver 140 is supplied with ink. This is made possible by the fact that the feed pump 120 is put into operation, and generates a negative pressure at the pump sump 170 on the suction side 122. The fluid is thus sucked at the pump sump 170 through the feed pump 120, and conveyed in the direction of the pressure side 124 to the fluid receiver 140. There the printing process takes place. Excess fluid or excess paint is collected in the fluid trough 150 and sucked off by the return pump 130 via the suction side 132. Via the pressure side 134, which is in fluid communication with the fluid supply 20, the paint or the fluid is introduced into the mixing device 10 and distributed there via the outlet arms 30 radially outward. The outlet is via the outlet openings 32, so that the fluid within the container 110 is rotated. The entire mixing device, in particular the outlet arms 30, are arranged rotationally fixed relative to the container 110. By the rotation of the fluid in the container 110, a mixing of the fluid takes place, so that in a color composition with thixotropic properties, the viscosity is reduced by the introduction of these shear forces. Additional fittings such. B. agitators are not required.

In addition to carrying out the printing process itself and a corresponding mixing according to the invention, preconditioning can also be carried out independently of an application of fluid to the fluid receiver 140. For this purpose, three valves 120a, 130a and 160a are provided. For the preconditioning, z. B. after filling the container 110 with fluid and before starting a printing operation, the valves 120a (flow valve) and 130a (return valve) are closed and a bypass valve 160a opened. The two pumps 120 and 130 thus allow a smaller circuit, which allows a circulation of the fluid independently of the fluid receiver 140. Thus, a mixing according to the invention can take place as preconditioning. Is in this preconditioning in addition, z. B. intermittently, the return valve 130 a is opened, so air is sucked from the empty fluid tank 150. This intermittent suction can, for. B. with a clock of 2 seconds to about 10 seconds, so that intermittently in addition to fluid and air packets from the outlet openings 32 of the outlet arms 30 are delivered. These air packages rise vertically upwards and thus provide additional vertical mixing.

Further, the mixing device 10 is the FIG. 1 formed such that the lower end of the fluid supply 20 is provided with an additional opening 22. This is aligned in particular with an outlet direction along the container axis 114, so that any dead spaces formed below this connection region between the fluid supply 20 and the connection arms 30 are avoided or reduced.

In FIG. 2 a further embodiment of a fluid system 100 according to the invention is shown. The ports are for fluidly communicating with the suction side 122 of the feed pump 120 and the pressure side 134 of the return pump 130. In this embodiment, the container 110 is formed with a container bottom and a container wall 112 which generally entail a substantially cylindrical configuration of the container 110 , The individual outlet arms 30 are provided with outlet directions A for the outlet openings 32, which are arranged by the curvature of the outlet arms 30 substantially tangentially along a common circumference U. In addition, the container bottom of the container 110 is chamfered on at least one side, so that a supply of the fluid in the direction of the pump sump 170 takes place.

The FIGS. 3 and 4 show an embodiment of mixing devices 10. So is in FIG. 3 an embodiment with four outlet arms 30 shown, wherein the individual outlet openings 32 each have an outlet direction A, which are arranged tangentially or substantially tangentially to a common circumferential direction U. For this purpose, all Aüslassarme 30 extend radially from the fluid supply 20 by substantially the same amount away, so that the common circumference U results.

FIG. 4 shows an embodiment of the mixing device 10, in which two outlet arms 30 are provided. These also have a substantially equal radial extent, so that a common circumference U is formed. However, this is Embodiment provided a horizontal angular position over a horizontal angle H of the outlet directions A of the two outlet openings 32. This horizontal angle H lies in the plane which is spanned by the outlet arms 30, between the tangent T to the common circumferential direction U and the respective outlet direction A.

In FIG. 5 an embodiment is shown which has a vertical adjustment with a vertical angle V. Regarding FIG. 5 Here, a vertical angle V can be defined in a manner similar to the horizontal angle H. Thus, for example, a tangential T is provided at the common circumference U, wherein a tilting of the outlet direction A downwards, ie in the vertical direction. Here it is also easy to see that a design of the Auslassarmes 30 is provided with a substantially round outer cross section and free round inner cross section.

The FIGS. 6, 7 and 8 show three different embodiments of a mixing device 10 according to the invention for better clarity, these three figures show the mixing device 10 in the development along the circumferential direction. FIG. 6 shows a variant with alternately arranged outlet openings 32. The outlet directions A show here in different directions with respect to the horizontal plane (shown here as a dashed line). The amounts of the vertical angle V are in particular identical. In each case an outlet opening 32 is thus directed to the bottom surface of the container 110, while each second outlet opening 32 is directed away from the bottom surface of the container 110. Thus, foaming on the surface of the fluid stored in the container 110 can be effectively avoided. A variant of this embodiment is in FIG. 7 shown. So there is a double alternation. Always two outlet openings 32 each show alternately in the same direction. FIG. 8 shows an embodiment in which each second outlet opening 32 is directed upward. Thus, a minimal embodiment is shown to achieve the reduction of foaming.

The above explanation of the embodiment is made only in the context of examples. Of course, individual features of the embodiments, if technically feasible, can be freely combined. LIST OF REFERENCE NUMBERS 10 mixing device 20 fluid supply 22 additional opening 30 outlet arm 32 outlet 100 fluid system 110 container 112 Wall of the container 114 container axis 120 flow pump 120a Supply valve 122 Suction side of the flow pump 124 Pressure side of the flow pump 130 Return pump 130a Return valve 132 Suction side of the return pump 134 Pressure side of the return pump 140 fluid receiver 150 fluid bath 160 bypass 160a bypass valve 170 sump A Outlet V vertical angle H Horizontal angle U Common scope T tangent

Claims (15)

1. Mixing device (10) for mixing a fluid in a container (110) of a fluid system (100) of a printing machine, having a fluid feed (20) and at least one outlet arm (30) with an outlet opening (32), wherein the fluid feed (20) is fluidically connected to the at least one outlet arm (30), wherein the outlet opening (32) is oriented to discharge the fluid with an outlet direction (A) in order to set at least part of the fluid in the container (110) in rotation, wherein at least part of the at least one outlet arm (30) is curved along a curve, wherein a multiplicity of outlet arms (30) are formed and all the outlet arms (30) are curved in the same direction,
   characterized in that
   a spiral design for the outlet arms (30) is provided so as to continuously push the rotation of the fluid in the container (110).
2. Mixing device (10) according to Claim 1,
   characterized in that
   at least part of the at least one outlet arm (30) extends perpendicular or essentially perpendicular to the fluid feed (20).
3. Mixing device (10) according to either of the preceding claims,
   characterized in that
   the outlet opening (32) is oriented for the outlet direction (A) of the fluid with a vertical angle (V) and/or a horizontal angle (H), wherein the vertical angle (V) and/or the horizontal angle (H) is less than 90°, in particular less than approximately 85°.
4. Mixing device (10) according to Claim 3,
   characterized in that
   there are provided at least two outlet arms (30), each with one outlet opening (32), wherein the outlet openings (32) have different vertical angles (V), in particular with different signs with respect to the horizontal plane.
5. Mixing device (10) according to Claim 4,
   characterized in that
   all of the outlet openings (32), alternating in the circumferential direction, have different signs for the vertical angles (V) with respect to the horizontal plane.
6. Mixing device (10) according to either of Claims 4 and 5,
   characterized in that
   the vertical angles (V) below the horizontal plane are in the range between 2° and approximately 7°, and/or the vertical angles (V) above the horizontal plane are in the range between approximately 10° and approximately 20°.
7. Mixing device (10) according to one of the preceding claims,
   characterized in that
   there are provided at least two outlet arms (30) which are oriented for outlet directions (A) of the fluid along a common circumference (U), and/or in that there are provided at least two outlet arms (30) which are distributed regularly or essentially regularly around the fluid feed (20).
8. Mixing device (10) according to one of the preceding claims,
   characterized in that
   there are provided at least two outlet arms (30) which extend at least partially in a common plane.
9. Mixing device (10) according to one of the preceding claims,
   characterized in that
   the fluid feed (20) is designed to extend in the container (110) along or parallel to the container axis (114), in particular into the lower half of the container (110).
10. Mixing device (10) according to one of the preceding claims,
    characterized in that
    the fluid feed (20) has, in the region of the connection with the at least one outlet arm (30), at least one additional opening (22) in order to avoid dead zones in this region.
11. Fluid system (100), in particular for inks in a printing machine, having at least one container (110) for storing a fluid, and outflow pump (120) and a return-flow pump (130) for delivering the fluid, a fluid receiver (140), in particular a printing roller, and a fluid trough (150) for providing and/or catching the fluid for and/or from the fluid receiver (140), wherein the outflow pump (120) is designed to deliver the fluid from the container (110) to the fluid receiver (140) and the return-flow pump (130) is designed to deliver the fluid from the fluid trough (150) back into the container (110),
    wherein
    there is provided a mixing device (10) having the features of one of Claims 1 to 10, wherein the fluid feed (20) of the mixing device (10) is fluidically connected to the pressure side (134) of the return-flow pump (130).
12. Fluid system (100) according to Claim 11,
    characterized in that
    the pressure side (124) of the outflow pump (120) is fluidically connected to the suction side (132) of the return-flow pump (130) via a bypass (160).
13. Fluid system (10) according to either of Claims 11 and 12,
    characterized in that
    the outlet opening (32) of the at least one outlet arm (30) is arranged between approximately 20% and approximately 80% of the radial distance between the fluid feed (20) and the surrounding wall (112) of the container (110), and/or in that the mixing device (10) is arranged so as not to rotate with respect to the container (110).
14. Method for mixing a fluid in a container (110), in particular of a fluid system (100), using a mixing device (10), having the following step:

    - introducing fluid from an outlet opening (32) of at least one outlet arm (30) into the container (110) with an outlet direction (A) which is oriented in order to set at least part of the fluid in the container (110) in rotation,

    wherein
    the method for mixing a fluid is carried out using a fluid system (100) having the features of one of Claims 11 to 13.
15. Method according to Claim 14,
    characterized in that,
    for the purpose of pre-conditioning the fluid in the container (110), air is introduced, in particular pulsed, from the outlet opening (32) of the at least one outlet arm (30) into the container (110).

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