Dosing machine with rotary lobe pump

Abstract

Dosing machine (1) for processing a dough or a mass (3), wherein the dosing machine (1) has a rotary piston pump (2), by means of which the dough or the mass (3) can be conveyed from a feed area (4) of the dosing machine (1) to a dosing area (5) of the dosing machine (1), and wherein at least one dosing opening (6) is arranged in the dosing area (5), through which the dough or the mass (3) can be led out of the dosing machine (1), characterized in that a first pair of rotary pistons (8) and a second pair of rotary pistons (9) are arranged in a pump chamber (7) of the rotary piston pump (2), wherein each pair of rotary pistons (8, 9) has a first rotary piston (10a, 10b) and a second rotary piston (11a, 11b), wherein the first rotary pistons (10a, 10b) of the rotary piston pump (2) are arranged on a first piston shaft (12). and when the dosing machine (1) is used as intended, rotate around a first rotation axis (13), wherein the second rotary pistons (11a,11b) are arranged on a second piston shaft (14) and, when the dosing machine (1) is used as intended, rotate about a second axis of rotation (15), wherein the first rotary pistons (10a, 10b) of a pump chamber (7) are rotated relative to one another about the first axis of rotation (13) by an angle of rotation (16), and wherein the second rotary pistons (11a, 11b) of a pump chamber (7) are rotated relative to one another about the second axis of rotation (15) by the angle of rotation (16).

Description

[0001] The invention relates to a dosing machine for processing a dough or a mass, wherein the dosing machine has a rotary piston pump by means of which the dough and / or the mass can be conveyed from a feed area of ​​the dosing machine to a dosing area of ​​the dosing machine and wherein at least one dosing opening is arranged in the dosing area through which the dough or the mass can be led out of the dosing machine.

[0002] Such dosing machines are used in particular for dosing doughs and masses in production lines in the food industry and usually have a conveyor or steel belt onto which the dough or mass is placed by the dosing machine, whereby the dough or mass can be fed to further processing devices by means of the conveyor or steel belt.

[0003] A key step in the industrial production of dough or mass products using such a production line is the precise dosing of the dough or mass for each individual pre-product from which the products are to be manufactured using the production line. In addition to high precision in dosing the dough or mass, another requirement for the dosing machine is that it must be capable of dosing doughs and masses with a wide variety of consistencies and compositions.

[0004] With regard to the consistency of the dough or mass, lumpy inclusions in particular pose a particular challenge, as they are very easily destroyed during conveying of the dough or mass. Examples of lumpy inclusions include nuts, especially hazelnuts, almonds, walnuts, Brazil nuts, and the like; dried fruits, especially raisins, sultanas, prunes, or the like; chocolate pieces, especially white chocolate, dark chocolate, or milk chocolate; baking ingredients such as candied lemon or orange peel pieces; ingredients to change the mouthfeel, for example to increase crispness, such as puffed rice, chips, biscuit pieces, or the like. In addition, fruit, vegetable, and spice pieces or preparations, as well as rock candy, pistachios, and cocoa beans, can also be included as lumpy inclusions in the dough or mass.

[0005] Essentially two embodiments of dosing machines are known from the prior art which at least partially meet these requirements.

[0006] First, there are dosing machines that have at least one gear pump. In dosing machines with gear pumps, the dough or mass is conveyed via a number of gears from a feed area of ​​the dosing machine to a dosing area of ​​the dosing machine. A particular disadvantage of using gear pump systems for conveying dough and masses is that they cannot be conveyed without destroying the lumpy inclusions contained within them.

[0007] Furthermore, dosing machines for conveying dough and masses are also known, which have at least one sine pump. Sine pumps are characterized by having a disc-shaped rotor, which is designed as a wave-shaped displacement means and which conveys a medium to be conveyed in a sinusoidal, pulsating manner through a cylindrical chamber. A particular disadvantage of such sine pumps is that it is not possible to achieve an approximately constant volume flow with which to convey the dough or mass. As a result, the continuous, uniform pressing of strands of dough or mass, as is required, for example, in the production of bar-shaped products, in particular chocolate bars, is not possible with such a dosing machine.

[0008] When it comes to doughs and masses, the food industry usually distinguishes between doughs, masses, and other masses. Doughs are intermediate products in food production, consisting of at least one flour and at least one liquid. Masses are intermediate products in food production, consisting of at least one flour and at least one liquid, with a greater proportion of liquid than flour. Other masses are semi-finished products, particularly sugar, fat, or chocolate masses. Other masses are processed, for example, in the hygiene, meat, dairy, or animal feed industries.

[0009] A dosing device with reciprocating pistons that convey a confectionery mass from a container to a dosing area is known, for example, from DE 25 38 938 A1.

[0010] A similar dosing device with dough feed piston is described in DE 10 2015 217 120 A1.

[0011] The requirements for the dosing machine are essentially similar with regard to dosing doughs, masses, and other masses. Therefore, for the sake of clarity, the following description of the functioning of the dosing machine according to the invention will omit a distinction between doughs, masses, and other masses and the term "mass" will be used for all three terms. All statements are readily applicable to the use of the dosing machine according to the invention with doughs, masses, and other masses.

[0012] In summary, it can be stated that with the dosing machines known from the state of the art, it is not possible to convey a mass, regardless of its consistency, with an approximately constant volume flow. In particular, it is not possible to convey masses with lumpy inclusions without destroying and / or deforming these lumpy inclusions.

[0013] It is therefore considered an object of the present invention to provide a dosing machine which makes it possible to convey a large number of masses of very different compositions, wherein an approximately constant volume flow can be set.

[0014] This object is achieved according to the invention in that a first pair of rotary pistons and a second pair of rotary pistons are arranged in a pump chamber of the rotary piston pump, each pair of rotary pistons having a first rotary piston and a second rotary piston, the first rotary pistons of the rotary piston pump being arranged on a first piston shaft and rotating about a first axis of rotation when the dosing machine is used as intended, the second rotary pistons being arranged on a second piston shaft and rotating about a second axis of rotation when the dosing machine is used as intended, the first rotary pistons of a pump chamber being rotated relative to one another about the first axis of rotation by an angle of rotation, and the second rotary pistons of a pump chamber being rotated relative to one another about the second axis of rotation by the angle of rotation.Such a design ensures that the mass can be conveyed through the pump chamber to the dosing opening by means of the rotary piston.

[0015] Advantageously, each dosing opening can be supplied with the compound from a pump chamber associated with the dosing opening. This ensures that an approximately equal amount of compound can be deposited onto the conveyor belt of the production line via each dosing opening.

[0016] In a particularly preferred implementation of the inventive concept, it is further provided that the feed area can be operatively connected to additional conveying devices, in particular to generate a pre-pressure with which the mass enters the pump chamber. Such conveying devices can, for example, comprise feed rollers, screw conveyors, or the like.

[0017] The invention also provides for the assignment of pump chambers to metering openings to be selectable. "Selectable" in this case means both that the assignment can be determined by design and that the assignment can be variable, for example, by a slide, by dies, by guide plates, or the like.

[0018] To convey particularly large quantities of the compound, it is advantageously also provided that a dosing opening can be fed from a plurality of pump chambers. In contrast, it is also advantageously provided that the dosing machine according to the invention can be designed such that a plurality of dosing openings can be fed from a single pump chamber. This is particularly advantageous when small quantities of the compound are to be conveyed.

[0019] In the dosing machine according to the invention, it is further provided that the rotary pistons have a cross-section that approximately corresponds to the shape of an 8. The pistons are adapted to one another and aligned with one another in such a way that they cyclically engage with one another during operation of the rotary piston pump in such a way that a gap between the two pistons is minimized in a sealing area.

[0020] In working volumes swept by the rotary pistons of a pair of rotary pistons, namely a first working volume of the first rotary piston and a second working volume of the second rotary piston, an inlet volume, an outlet volume and at least one delivery volume of the first rotary piston and / or at least one delivery volume of the second rotary piston are cyclically formed. The inlet volume formed by the first and second rotary pistons and a chamber wall of the pump chamber is open to an inlet opening of the pump chamber. During rotation of the rotary pistons, the inlet volume increases up to a maximum size, increasing alternately in the direction of the first rotary piston and the second rotary piston. When the maximum size is reached, the inlet volume is closed off towards the inlet opening by the rotary piston in whose direction the inlet volume has increased.The closed inlet volume then forms the delivery volume, which is formed by the chamber wall and the respective rotary piston. The delivery volume rotates around the respective rotary piston in the direction of its rotation and is opened up to an outlet opening of the pump chamber when the rotary piston reaches a certain position. The opened delivery volume then forms the outlet volume. The inlet volume formed by the first and second rotary pistons and the chamber wall of the pump chamber decreases during the rotation of the rotary pistons, whereby the mass is transported out of the pump chamber. It is intended that the metering opening is connected to the outlet opening, or that the metering opening is formed by the outlet opening.

[0021] In rotary lobe pumps, which have only one pair of rotary lobes per pump chamber, where the rotary lobes arranged adjacent to each other on a shaft do not rotate relative to each other, the pumped medium is pumped in a pulsating manner due to the sharply defined delivery volumes.

[0022] By means of the rotation of the first rotary pistons and the second rotary pistons relative to one another by the angle of rotation provided in the dosing machine according to the invention, it is achieved that the mass can be conveyed with an approximately constant volume flow, since in each pump chamber at least one outlet volume is always brought into operative connection with the outlet opening.

[0023] In an embodiment of the dosing machine according to the invention, the rotary piston pump is provided with at least two pump chambers, wherein the pump chambers are arranged adjacent to one another. Advantageously, it is also provided that all first rotary pistons of all pump chambers are arranged on the first piston shaft, and all second rotary pistons of all pump chambers are arranged on the second piston shaft.

[0024] Advantageously, the number and design of the pump chambers of the dosing machine according to the invention can be adapted to the respective requirements. For example, it is possible for the dosing machine to have a plurality of pump chambers, so that even production lines with very wide conveyor belts can be fed using the dosing machine according to the invention.

[0025] Furthermore, it is also possible and intended for the dosing machine to have differently designed pump chambers, in particular to be able to deposit different masses onto the same conveyor belt. This makes it possible, for example, to produce different precursors in a single operation.

[0026] With the dosing machine according to the invention it is possible to convey masses that have a proportion of lumpy inclusions of up to 100%.

[0027] An advantageous embodiment of the inventive concept provides that the first axis of rotation is aligned parallel to the second axis of rotation, wherein the first piston shaft and the second piston shaft are coupled to one another with a transmission ratio of 1 to -1. In this case, it is advantageously provided in particular that the dosing machine has a plurality of identical pump chambers with identical rotary pistons. Such a design of the dosing machine makes it possible to realize them with a particularly large working width, wherein the volume flow at each dosing opening can be adjusted to be largely constant across the entire working width. This is particularly advantageous in large-scale industrial production processes in order to be able to achieve the highest possible process efficiency by means of the widest possible production lines.

[0028] To prevent damage to the rotary pistons when using similar rotary pistons, in particular similar first and second rotary pistons of the respective rotary piston pairs, the transmission ratio between the first piston shaft and the second piston shaft is 1 to -1. Different rotational speeds of similar rotary pistons would lead to damage to the dosing machine.

[0029] It is advantageously provided that the transmission ratio of 1 to -1 between the first piston shaft and the second piston shaft can be implemented using a wide variety of technical solutions. The transmission ratio can be implemented, for example, using a mechanical device, in particular a gearbox. Furthermore, the transmission ratio can also be implemented by electrically synchronizing electric motors, each of which is assigned to and drives one of the piston shafts. Electrical synchronization is particularly advantageous when the piston shafts are to be subjected to high torques.

[0030] An advantageous implementation of the inventive concept provides for the first and second piston shafts to be mechanically coupled to one another. Mechanical couplings of shafts are common and well-established in plant engineering. They are simple in design and can be implemented inexpensively. Other options for coupling the first and second piston shafts of the dosing machine according to the invention include, for example, magnetic, hydraulic, or pneumatic coupling systems or devices.

[0031] In a preferred embodiment of the dosing machine according to the invention, a wall element is arranged between each adjacent pair of rotary pistons in the pump chamber, wherein the delivery areas assigned to the adjacent pairs of rotary pistons are separated from one another by each wall element. The wall element provided according to the invention prevents a displacement of the mass from the delivery area of ​​the first pair of rotary pistons into the delivery area of ​​the second pair of rotary pistons in the pump chamber. The wall element is designed such that the masses delivered by the pairs of rotary pistons are brought together before exiting the pump chamber. This design of the rotary piston pump increases the pumping efficiency of the rotary piston pump. Particularly preferably, the pumped masses are collected in a collection chamber, toward which both outlet openings are open, with the collection volume being open toward the metering opening(s) assigned to the pump chamber. Due to the angle of rotation formed between the rotary pistons, when the metering machine is used as intended, mass is continuously introduced into the collection chamber, which then exits the metering machine through the metering opening at a constant volume flow. Residual pulsations are advantageously compensated by the damping properties of the mass.

[0032] An advantageous embodiment of the inventive concept provides for the angle of rotation to be between 35 degrees and 60 degrees, preferably 45 degrees. Setting the angle of rotation to a value within the specified range has proven particularly advantageous when processing mass. A 45-degree angle of rotation is particularly preferable. One factor that decisively influences the selection of the appropriate angle of rotation is the geometry of the rotary pistons.

[0033] It is provided that the angle of rotation is advantageously selected such that the outlet opening is always operatively connected to an outlet volume of one of the rotary pistons arranged in the pump chamber, while the inlet opening is always operatively connected to an inlet volume of one of the rotary pistons arranged in the pump chamber. Such a configuration of this particularly preferred embodiment of the dosing machine enables a permanent suction of mass from the feed area and a permanent ejection of mass into the dosing area.

[0034] An advantageous implementation of the inventive concept provides for at least one of the piston shafts to be driven by an external drive device. With a large number of production lines, it is common for individual machines on the production line to be driven by a central drive unit. Drive via a drive chain is merely an example. The use of a central drive device is well-managed and inexpensive to implement.

[0035] An advantageous embodiment of the inventive concept provides that the dosing machine has an integrated drive unit. In such an embodiment of the dosing machine according to the invention, the drive unit is provided as a component of the dosing machine. Preferably, the drive unit only needs to be coupled to a suitable energy source and a compatible control unit to operate the dosing machine.

[0036] One advantage of the integrated drive unit is that the mechanical processes of the dosing machine are decoupled from those of the production line, making it easier to adjust to different operating conditions. For example, it allows the running speed of the production line to be changed without having to affect the volume flow from the dosing machine. In a particularly advantageous implementation of the inventive concept, the integrated drive unit comprises an electric motor and / or a hydraulic motor and / or a pneumatic motor. In large-scale industrial plants, such as production lines, a wide variety of energy sources are commonly used to drive the individual components of the production line. Various embodiments of drive means are mentioned here purely as examples. These can be driven electrically, hydraulically, using a compressed fluid, or pneumatically, using a compressed gas.

[0037] In an advantageous embodiment of the dosing machine according to the invention, the rotary pistons are made of a plastic, at least in sections. The plastic used is particularly preferably a food-safe plastic. The use of plastic as the material for the rotary pistons of the dosing machine according to the invention is particularly advantageous if the rotary pistons are to be designed particularly cost-effectively.

[0038] An advantageous embodiment of the inventive concept provides that the rotary pistons are made of a metallic material, at least in sections. The use of metallic materials is particularly advantageous when high load capacity and long-term durability of the dosing machine according to the invention are required. This is particularly the case in large-scale industrial production lines.

[0039] With regard to the material from which the rotary pistons are made, the invention provides that this can be adapted to the respective intended use of the dosing machine.

[0040] In order to process temperature-sensitive masses and / or masses with temperature-sensitive inclusions, the invention also provides for the dosing machine to have a temperature control device. The temperature control device can be used to change the temperature of the dosing machine and / or a volume enclosed by the dosing machine, at least in sections. The temperature control device can, for example, comprise electrical heating and / or cooling elements, heating and / or coolant lines, compressors, Peltier elements, or the like.

[0041] Furthermore, it is also possible and provided that the dosing machine according to the invention can be designed in such a way that the mass can be pressed out and / or skin-passed. In this case, pressing out means that a strand is created from the mass. Skin-passing means that the mass is pressed out or metered in bursts. It is provided that the mass is conveyed continuously during pressing, with conveying of the mass being cyclically interrupted during skin-passing, for example by stopping the rotary pistons. Advantageously, it is also provided that the rotary pistons can be cyclically set into a backward movement opposite to a conveying movement during skin-passing.

[0042] In the following, some embodiments of the inventive concept are explained in more detail, which are shown in the drawing.

[0043] It shows: Fig. 1 is a schematic sectional view of a dosing machine according to the invention, Fig. 2 a partial schematic representation of a part of a production line designed as a baking line with a dosing machine according to the invention, Fig. 3 an isometric representation of a piston arrangement on piston shafts with wall elements of a dosing machine according to the invention and Fig. 4 and Fig. 5 isometric representations of a dosing machine according to the invention.

[0044] In Fig. Figure 1 shows a schematic sectional view of a dosing machine 1 according to the invention, which has a rotary piston pump 2, by means of which a mass 3 can be conveyed from a feed area 4 of the dosing machine 1 to a dosing area 5 of the dosing machine 1. A dosing opening 6 is arranged in the dosing area 5, through which the mass 3 can be discharged from the dosing machine 1.

[0045] The rotary piston pump 2 has a first rotary piston pair 8 and a second rotary piston pair 9 in a pump chamber 7. The first rotary piston pair 7 has a first rotary piston 10a and a second rotary piston 11a of the first rotary piston pair 7, wherein the second rotary piston pair 8 has a first rotary piston 10b and a second rotary piston 11b of the second rotary piston pair 8.

[0046] The first rotary pistons 10a, b of the rotary piston pump 2 are arranged on a first piston shaft 12 and rotate about a first rotation axis 13. The second rotary pistons 11a, b of the rotary piston pump 2 are arranged on a second piston shaft 14 and rotate about a second rotation axis 15. The rotary pistons 10a, b, 11a, b are attached to the shaft.

[0047] The first rotary pistons 10a, b of the pump chamber 7 are rotated relative to one another around the first rotation axis 13 by a rotation angle 16. The second rotary pistons 11a, b of the pump chamber 7 are rotated relative to one another around the second rotation axis 15 by a rotation angle 16. The rotation angle 16 is 45° in the dosing machine 1 shown. The rotation axes 13, 15 are aligned parallel to one another, and the piston shafts 12, 14 are mechanically coupled with a gear ratio of 1 to -1.

[0048] In the rotary lobe pump 2 of the illustrated embodiment of a dosing machine 1 according to the invention, a wall element 17 is arranged between the first rotary lobe pair 8 and the second rotary lobe pair 9. The wall element 17 separates a first delivery area 18 of the first rotary lobe pair 8 from a second delivery area 19 of the second rotary lobe pair 9. Adjacent to the delivery areas 18, 19 is a collection volume 20, into which both the mass 3 delivered by the first rotary lobe pair 8 and the second rotary lobe pair 9 are introduced. The mass 3 is conveyed from the collection volume 20 into the dosing area.

[0049] In Fig. Figure 2 shows a schematic, perspective view of a production line 21 configured as a baking line, in which a dosing machine 1 according to the invention is used for dosing a dough (not shown or labeled). The dosing machine 1 conveys the dough from the feed area 4 by means of a rotary piston pump 2 to the dosing area 5, where the dough is deposited from two dosing openings 6, each in the form of two dough pieces 22, onto a conveyor belt 23.

[0050] The dosing machine 1 shown has a rotary piston pump 2 with two pump chambers 7. The dosing machine 1 is driven by an integrated drive unit 24 designed as an electric motor.

[0051] In Fig. 3 shows an arrangement of rotary piston pairs 8, 9 arranged on the first and second piston shafts 12, 14. Each rotary piston pair 8, 9 has a first rotary piston 10a, 10b and a second rotary piston 11a, 11b. A wall element 17 is arranged between each of the rotary piston pairs 8, 9. Each set of rotary piston pairs 8, 9 and a wall element 17 are arranged within a pump chamber in a dosing machine (not shown).

[0052] In the Fig. 4 and Fig. Figure 5 shows perspective views of another embodiment of the dosing machine 1 according to the invention. The illustrated embodiment has a multi-part pump chamber housing 25. A cover plate 26 can be removed from the pump chamber housing 25.

[0053] Eight pump chambers 7 are formed within the pump chamber housing 25, one of which is provided with a reference numeral for illustrative purposes. A first pair of rotary pistons 8 and a second pair of rotary pistons 9 are arranged within each pump chamber 7, with a wall element 17 being arranged between each pair of rotary pistons 8, 9.

[0054] In Fig. 5 is the Fig. 4 shows the metering device 1 without the cover plate (not shown or labeled). Removing the cover plate increases accessibility to the rotary piston pairs 8, 9, the pump chambers 7, and the wall elements 17, making them easier to clean and / or maintain. LIST OF REFERENCE SYMBOLS 1 dosing machine 2 rotary lobe pumps 3 Mass 4 Feeding area 5 Dosing range 6 Dosing opening 7 Pump chamber 8 first pair of rotary pistons 9 second pair of rotary pistons 10 a, b first rotary piston 11 a, b second rotary piston 12 first piston shaft 13 first axis of rotation 14 second piston shaft 15 second rotation axis 16 twist angles 17 Wall element 18 first funding area 19 second funding area 20 collection volumes 21 Production line 22 dough pieces 23 Conveyor belt 24 drive unit 25 Pump chamber housing 26 Cover plate

Claims

[1] Dosing machine (1) for processing a dough or a mass (3), wherein the dosing machine (1) has a rotary piston pump (2) by means of which the dough or the mass (3) can be conveyed from a feed area (4) of the dosing machine (1) to a dosing area (5) of the dosing machine (1), and wherein at least one dosing opening (6) is arranged in the dosing area (5), through which the dough or the mass (3) can be led out of the dosing machine (1), characterized bythat a first pair of rotary pistons (8) and a second pair of rotary pistons (9) are arranged in a pump chamber (7) of the rotary piston pump (2), each pair of rotary pistons (8, 9) having a first rotary piston (10a, 10b) and a second rotary piston (11a, 11b), the first rotary pistons (10a, 10b) of the rotary piston pump (2) being arranged on a first piston shaft (12) and rotating about a first axis of rotation (13) when the dosing machine (1) is used as intended, the second rotary pistons (11a, 11b) being arranged on a second piston shaft (14) and rotating about a second axis of rotation (15) when the dosing machine (1) is used as intended, the first rotary pistons (10a, 10b) of a pump chamber (7) being arranged around the first axis of rotation (13) by an angle of rotation (16) relative to one another are rotated and wherein the second rotary pistons (11a, 11b) of a pump chamber (7) are rotated relative to one another around the second axis of rotation (15) by the angle of rotation (16). [2] Dosing machine (1) according to claim 1, characterized by that the first axis of rotation (13) is aligned parallel to the second axis of rotation (15), wherein the first piston shaft (12) and the second piston shaft (14) are coupled to one another with a transmission ratio of 1 to -1. [3] Dosing machine (1) according to claim 2, characterized by that the first piston shaft (12) and the second piston shaft (14) are mechanically coupled to one another. [4] Dosing machine (1) according to one of claims 1 or 2, characterized by that a wall element (17) is arranged between adjacent pairs of rotary pistons (8, 9) of the pump chamber (7), wherein the delivery regions (18, 19) assigned to the adjacent pairs of rotary pistons (8, 9) are separated from one another by the respective wall element (17). [5] Dosing machine (1) according to one of claims 1 to 3, characterized by that the angle of rotation (16) is between 35° and 60°, preferably 45°. [6] Dosing machine (1) according to one of claims 1 to 5, characterized by that at least one of the piston shafts (12, 14) is driven by an external drive device. [7] Dosing machine (1) according to one of claims 1 to 6, characterized by that the dosing machine (1) has an integrated drive unit (24). [8] Dosing machine (1) according to claim 7, characterized by that the integrated drive unit (24) has an electric motor and / or a hydraulic motor and / or a pneumatic motor. [9] Dosing machine (1) according to one of claims 1 to 8, characterized by that at least one of the rotary pistons (10a, 10b, 11a, 11b) is made at least in sections from a plastic. [10] Dosing machine (1) according to one of claims 1 to 9, characterized by that at least one of the rotary pistons (10a, 10b, 11a, 11b) is made at least in sections from a metallic material.

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