Filling machine and method for filling a receptacle with granular food products

Abstract

The invention relates to a filling machine and to a method for conveying, and filling a receptacle with, granular food products, said filling machine comprising a conveying mechanism (23) which conveys the food product (12) to a product outlet (17), wherein a dynamic mixer is located upstream of the product outlet (17).

Description

[0001] Filling machine and method for filling granular food products

[0002] The invention relates to a filling machine for filling granular food products and a method for filling granular food products according to the preambles of claims 1 and 12.

[0003] Filling machines are well-established technologies. However, filling granular, i.e., lumpy, compressible food products presents a challenge. When granular food products (such as salads or ready-made meals) are conveyed and pumped into filling machines, particularly vacuum filling machines, the food product is compressed and takes on a corresponding shape. During the filling process, for example, via a metering valve into a package, some products develop a compact shape that essentially corresponds to the inner diameter of the metering valve or, if no metering valve is used, the inner diameter of the filling tube. This effect is often undesirable in practice when filling ready-to-eat meals.The compact food mass flows out as a continuous strand, which does not meet quality requirements for functional and aesthetic reasons.

[0004] Figure 5b shows a food mass 12, here for example pasta salad, in a package 11 in a loose form. Figure 5a shows the food mass 12 as it is ejected from a filling machine, for example, in a compressed form. In this form, the food is not very appealing. It can also happen that the desired fill quantity does not fit into the intended packaging, or protrudes, or extends into the sealing edge of the packaging, especially if the food mass is ejected as a compressed strand.

[0005] Therefore, manual rework by personnel is often necessary, involving the distribution and loosening of the food mass within the packaging, such as a tray, thermoformed mold, etc. Manual distribution makes the filling medium appear more aesthetically pleasing and ensures it fills all areas of the packaging. However, this is time-consuming and labor-intensive, making the manufacturing process disproportionately expensive and extending production time. Furthermore, manual rework is unacceptable from a hygiene perspective. Based on this, the present invention aims to provide a filling machine and a method that can easily fill granular food products with improved product appearance and greater process reliability.

[0006] According to the invention, this problem is solved by the features of claims 1 and 12.

[0007] The filling machine according to the invention, in particular a vacuum filling machine for filling granular food products, has a conveyor system that conveys the food product to a product outlet. From the product outlet, the food product can then be filled into packaging. Granular food products include, for example, lumpy, granular, compressible masses such as couscous salad, bulgur salad, pasta salad, rice salad, tuna, fresh meat, sliced ​​meat, diced ham, mashed potatoes, vegan mince, wrap and sandwich fillings, pulled pork, mac and cheese, crumbles for fine baked goods, and lumpy toppings.

[0008] According to the invention, a dynamic mixer is arranged upstream of the product outlet. This allows the food product, which has been compressed in the filling tube and / or metering valve of the filling machine, to be loosened by the dynamic mixer before being ejected from the product outlet. This results in an appealing appearance and allows it to be easily placed into packaging, such as a tray, without the need for manual distribution within the packaging. Granular, lumpy products can thus be produced cost-effectively and industrially in larger quantities without any negative impact on product appearance.

[0009] According to a preferred embodiment, the dynamic mixer is arranged either at the end of a filling tube or at the end of a metering valve, through which food product can be dispensed in portions. Here, a filling tube is understood to be a tubular outlet of the conveying system. Since the dynamic mixer is arranged at the end of either the metering valve or the filling tube, the food product can be dispensed in small quantities in the outlet direction R without being re-compressed.

[0010] Advantageously, the dynamic mixer is designed as an attachable unit for the metering valve or filling tube. This modular attachment allows for easy retrofitting and simple removal for cleaning, or at least partial replacement to meet changing requirements – for example, different mixing elements or housings. For this purpose, the dynamic mixer is preferably detachably connected to the metering valve or filling tube via a connecting device.

[0011] The connection device can, for example, include a screw connection, a snap connection, a clamp connection, or a bayonet connection. The connection device should preferably be designed such that the mixer is connected to the metering valve or the filling tube in a liquid-tight manner. This prevents moisture from escaping or external contaminants from reaching the food. As already explained, the dynamic mixer can then be easily removed and disassembled for cleaning purposes.

[0012] According to a preferred embodiment, the dynamic mixer comprises a mixer housing in which one or more mixing elements are rotatably mounted about a rotational axis D. The rotatably mounted mixing elements can be driven and rotate, for example, like a paddle wheel.

[0013] It is advantageous if the dynamic mixer has a drive to power a shaft with at least one mixing element. This allows for effective aeration of the food product; in particular, the aeration and output can be adjusted by changing the rotational speed. The rotational speed can also be adapted to the specific product and the conveying capacity of the conveyor system.

[0014] Advantageously, the drive is a pneumatic motor. A pneumatic motor is cost-effective and also has limited torque, thus minimizing the risk of injury at the product outlet, for example, if an operator accidentally inserts a finger. Furthermore, the high rotational speed deflects a finger from the outlet. The pneumatic motor can be controlled, for example, via a valve or a control command from the filling machine's control system, activating it and driving the shaft with the mixing elements. This can be done in different directions of rotation. An electric drive can also be suitable for performing the rotation, particularly if the applied torque is reliably monitored and limited.

[0015] According to a preferred embodiment, the dynamic mixer is designed, in particular, as a paddle-shaped mixer or as a paddle mixer and / or has, for example, one or more mixer shafts on which at least one, preferably several, mixing elements are arranged. The dynamic mixer preferably has a shaft with at least one, preferably several, flexible mixing elements distributed around the circumference, which extend outwards from the axis of rotation, particularly in a planar fashion. The mixing elements can be continuous or discontinuous.

[0016] Advantageously, the mixing elements are flexible, meaning they deform under counter-pressure. This flexibility eliminates any risk of mechanical injury to the operator. If an operator were to insert a finger into the product outlet, the mixing elements would not shear the finger off, but rather bend. Particularly in combination with the pneumatic motor, which has limited torque and, for example, cannot apply more than 120 N at the largest outer diameter of the dynamic mixer at a pneumatic pressure of 6 bar, the risk of injury is reduced to a non-critical level. Nevertheless, the mixing elements are designed to handle product transport.The separation forces in the food product are less than the force required to stop the pneumatic motor or to deform the mixing elements to such an extent that they become ineffective. This results in an intrinsically safe loosening and distribution solution for the food product without the need for any additional safety devices.

[0017] The flexible mixing elements are preferably made of at least one of the following materials which exhibit high elasticity, flexibility and food conformity: thermoplastic elastomers, natural rubber, silicones, polyurethanes, other synthetic or natural elastomers (SBR, NBR, EPDM, FKM).

[0018] According to another preferred embodiment, the action area of ​​the dynamic mixer, i.e., the orbit of the mixing elements, borders the product outlet.

[0019] This means that the rotating mixing elements push the food product directly outwards and not against a wall of the mixer housing, which would inevitably lead to product adhesion.

[0020] In the inventive method, granular food products can be filled, in particular with a filling machine according to at least one of claims 1 to 11. The filling machine's conveyor conveys the food product into a dynamic mixer, which loosens the food product before it is ejected from a product outlet. Advantageously, the granular food product is ejected in portions, in particular via a metering valve or the intermittent drive of the conveyor. That is, a specific portion is ejected by opening and closing the metering valve. This can also be achieved additionally or alternatively by intermittently driving the conveyor, i.e., conveying the food product for a specific time and stopping after conveying a specific quantity or mass of product. Similarly, for example...Depending on its geometric design, closing the valve piston expels a portion of the food product.

[0021] The food product is compacted by the conveyor and loosened by the dynamic mixer. Preferably, the dynamic mixer is driven by a motor. It is particularly advantageous if the speed of the dynamic mixer is adjustable, allowing the degree of loosening and, in particular, the distribution to be adjusted via the discharge velocity, and especially enabling the speed to be adapted to the food product or the conveying capacity of the conveyor.

[0022] According to a preferred embodiment, the food product is filled into a filling tube or a metering valve housing via the conveying system and then pushed into the action area of ​​the dynamic mixer, where it is captured by the mixing elements of the dynamic mixer rotating about a rotary axis D, loosened and conveyed to the product outlet.

[0023] In a preferred embodiment, when the desired portion size is reached, the valve closes, the valve piston closes, and the product located in the valve housing is also pushed towards the action area of ​​the dynamic mixer.

[0024] According to a preferred embodiment, a certain production quantity is ejected, after which the conveyor stops and / or the metering valve closes, after which the dynamic mixer is driven for a further certain time, in particular 0.1 to 2 seconds, and the entire food product is removed from the mixer housing.

[0025] Advantageously, the rotational speed can be maintained briefly even after the dosing process to ensure complete emptying of the housing. This guarantees that all the filling medium is removed from the mixer, ensuring consistent weight accuracy from portion to portion.

[0026] It is advantageous if the food is accelerated in the dynamic mixer. This improves the mixing. The invention is explained in more detail below with reference to the following figures.

[0027] Figure 1a shows a side view of a filling machine according to the present invention.

[0028] Figure 1b shows a front view of the filling machine shown in Figure 1a.

[0029] Figure 2 shows a figure of a further embodiment according to the present invention.

[0030] Figure 3 shows a perspective view of a metering valve with a dynamic mixer according to an embodiment of the present invention.

[0031] Figure 4 shows a schematic longitudinal section through a dynamic mixer according to an embodiment of the present invention.

[0032] Figure 5a shows a non-aerated food product according to the state of the art.

[0033] Figure 5b shows a loosened food product according to the present invention.

[0034] Figures 1a and 1b show a first embodiment of a filling machine 1 according to the present invention. As can be seen from the figures, a filling machine 1, for example a vacuum filling machine, has a hopper 14 arranged on the machine housing 15, through which the food product can be filled into the filling machine. The hopper 14 is connected to the conveying unit 23, for example a vane pump, by which the food product can be transported to a filling tube 2. In this embodiment, as can be seen from Figures 1a and 1b and also from the embodiment shown in Figure 3, a metering valve 3 is arranged on the filling tube 2, wherein the food product 12 is pushed through the filling tube opening 18 into the valve housing 4. Via a piston (not shown in Figure 3), the food product 12 can then be pushed towards a dynamic mixer 5, i.e., towards the product outlet 17.The metering valve 3 can be pneumatically controlled, for example via the machine control 22. A display 16 for operating the system is located on the front of the filling machine 1. As can be seen particularly in Figure 3, the dynamic mixer 5 is arranged upstream of the product outlet 17 at the end of the metering valve 3. The dynamic mixer 5 is designed as an attachable attachment; in particular, the attachment can be mounted to the metering valve 3 or directly to a filling tube 2.

[0035] The dynamic mixer 5 can be detachably connected to the metering valve 3 via a connecting device 19 or simply to the filling tube 2. The connecting device 19 can, for example, have a screw connection, a clamp connection, or a bayonet fitting. In any case, the connecting device 19 is designed to tightly connect the dynamic mixer 5, preventing any unwanted leakage of liquid components of the food products.

[0036] The dynamic mixer 5 has a mixer housing 6 in which mixing elements 7 are rotatably mounted about a pivot axis D. The dynamic mixer can also have a drive 8 to drive, i.e., rotate, a shaft 13 carrying the mixing elements 7. Advantageously, the drive 8 is designed as a pneumatic motor 8. However, other drives, such as a hydraulic or electric motor, can also be used. The use of a pneumatic motor is simple and cost-effective. As shown in Fig. 3, the pneumatic motor 2 has pneumatic connections 9a and 9b, which are connected via connections 10a and 10b to an external or internal pneumatic system for supplying the drive air. The drive 8 can be controlled via valves and control commands from the machine control 22. The direction of rotation can also be changed. The drive speed, start time, and end time or overrun time can also be adjusted.The overrun time is the time during which the dynamic mixer is still driven after the metering valve 3 closes and / or the conveying unit stops, because a predetermined portion quantity has been conveyed.

[0037] According to a preferred embodiment, the dynamic mixer is designed as a paddle wheel mixer. The dynamic mixer 5, for example, has a shaft 13 with several flexible mixing elements 7 distributed around its circumference. In this embodiment, there are three mixing elements 7 extending radially outwards. The mixing elements 7 are arranged around the shaft 13 at 120° intervals relative to each other. The mixing elements 7 have, for example, a substantially rectangular cross-sectional shape. This design is merely an example. The geometry can be adapted to different configurations for different applications and food products. The mixing elements can be continuous, as shown here, or interrupted, or offset from each other. Only one mixing element can be arranged on the shaft, or several shafts, each with at least one mixing element, can be provided.

[0038] The outer edges 24 of the mixing elements, which extend, for example, essentially parallel to the axis of rotation D, can either brush against the inner wall of the housing 6 during their rotational movement or be spaced away from the inner wall. A spacer can be advantageous so that the drive force is not dissipated by friction. Alternatively, the mixing elements can also be designed to be more flexible and brush against or pass by the inner wall, as, for example, in a car windshield wiper.

[0039] The mixing elements 7 are designed to be flexible, meaning they bend or deform under counter-pressure. This flexibility eliminates any risk of mechanical injury to the operator at the machine. If an operator were to insert a finger into the product outlet, the mixing elements would not shear the finger off, but rather bend. Particularly in combination with the pneumatic motor, which has limited torque and, for example, cannot apply more than 120 N at the largest outer diameter of the dynamic mixer at a pneumatic pressure of 6 bar, the risk of injury is reduced to a non-critical level. Nevertheless, the mixing elements 7 are designed to handle product transport.The separation forces in the food product are less than the force required to stop the pneumatic motor or to deform the mixing elements to such an extent that they become ineffective. This results in an intrinsically safe loosening and distribution solution for the food product without the need for any additional safety devices.

[0040] The flexible mixing elements are preferably made of at least one of the following materials which exhibit high elasticity, flexibility and food conformity: thermoplastic elastomers, natural rubber, silicones, polyurethanes, other synthetic or natural elastomers (SBR, NBR, EPDM, FKM).

[0041] As can be seen in Fig. 4, the operating area A of the dynamic mixer, in particular the orbit of the mixing element(s), borders the product outlet 17. This means that the rotating mixing elements 7 preferably push the food product outwards and not against a wall of the mixer housing. Figure 2 shows a further embodiment that corresponds to the embodiment shown in Figures 1 to 4, with the exception that the dynamic mixer 5 is attached to the filling tube without an intermediate metering valve 3, as described above.

[0042] In the previously described embodiments, the dynamic mixer is designed as an attachment. The dynamic mixer can also be integrated into the filling tube or the metering valve.

[0043] In the embodiments shown above, the dynamic mixer is arranged horizontally, meaning it rotates about a horizontal axis of rotation D. The dynamic mixer 5 could also be arranged vertically, in which case the product outlet 17 would be located laterally. An inclined arrangement is also possible. However, it is advantageous to utilize gravity to direct the product distribution as precisely as possible in one direction. The outlet direction can be influenced by tilting the valve or positioning the outlet opening 17 clockwise or counterclockwise. In Figures 3 and 4, the outlet opening 17 is directed downwards. As can be seen in Figure 4, part of the left wall of the mixer housing is missing and extends diagonally outwards, which facilitates the discharge of the product.

[0044] The process according to the invention proceeds as follows:

[0045] The following describes an embodiment in which a specific portion of food is dispensed in portions. However, the present invention, i.e., the use of the dynamic mixer, is also suitable for the continuous dispensing of a granular food product.

[0046] A granular food product 12, for example couscous salad, bulgur salad, pasta salad, rice salad, tuna, fresh meat, sliced ​​meat, diced ham, mashed potatoes, vegan mince, wrap and sandwich fillings, pulled pork, mac and cheese, crumble for fine baked goods, chunky toppings or other chunky, granular, compressible, moist food products is introduced into the hopper 14.

[0047] A filling cycle then begins for each portion. First, the metering valve 3 opens, releasing the valve inlet / filling tube outlet 18 and the product outlet 17 of the metering valve 3. The food product 12 is fed via the conveyor 23 into the filling tube 2 and into the valve housing 4, thus filling the valve housing 4. During this process, the food product 12 is compressed and compacted to generate the propulsion.

[0048] The drive, here the pneumatic motor 8, is controlled via a valve (not shown), for example via a control command from the machine control 22 of the filling machine, and sets the associated dynamic mixer 5 in motion. This can occur in different directions of rotation. The rotational speed is adjusted to the desired loosening, the specific product, and the conveying capacity of the conveyor system.

[0049] The optimal speed can be determined empirically, for example. Alternatively, the speed can be fixed using a throttle.

[0050] The food product then enters the action area of ​​the dynamic mixer 5 and is captured by one of the flexible mixing elements 7. The other mixing elements 7 also gradually engage with the food product 12 and loosen the food product.

[0051] The food product 12 is transported between the mixing elements 7, and in particular accelerated. For effective aeration, the rotational speed of the mixing elements can be greater than the flow velocity of the product at the valve outlet. The food product can exit the mixer housing 6 through the product outlet 17 in the lower region of the mixer housing 6 and be pushed outwards by the mixing elements. The outlet area of ​​the mixer housing 6 is designed such that its geometry prevents the formation of deposits; that is, the mixing elements push the food product outwards through the product outlet 17 without it being compressed against the mixer housing wall.

[0052] Small quantities of the food product are dispensed, corresponding to the maximum volume between the mixing elements 7. Ideally, the volume between the mixing elements is greater than the volume dispensed from the valve per unit of time. The small quantities fall into the packaging below. Once the desired portion size is reached, the filling process stops; that is, the piston of the metering valve 3 closes and pushes the product in the valve housing 4 towards the dynamic mixer 5. It may be necessary for the dynamic mixer 5 to continue operating briefly after the metering process to ensure complete emptying of the mixer housing 6. Therefore, after the metering process is complete, it is advantageous for the drive, in particular the pneumatic motor 8, to keep the dynamic mixer 5 running for a specific overrun time, specifically 0.1 to 2 seconds.After the valve piston closes, it continues to move to ensure that all food product is removed from the interior of the mixer housing 6. This ensures weight accuracy from portion to portion.

[0053] Depending on the food product, the opening and closing process of the valve piston is optional. This means that a device can also be used that does not have a metering valve 3, but instead dispenses the food product 12 via a filling tube 2. The portion size is then set via the intermittent operation of the conveyor 23. After the conveyor pushes the food product into the dynamic mixer 5, as described above, small quantities of the food product are discharged into a package located below, also as described above. As soon as the desired portion size is reached, the conveyor 23 stops. As also described above, the dynamic mixer 5 can then continue to run for a certain overrun time, for example, 0.1 to 2 seconds, until all the food product has been removed from the interior of the mixer housing 6.

[0054] The degree of loosening is adjusted via the speed of the pneumatic motor or power transmission element. Increasing the speed of the drive motor increases the degree of loosening, as it reduces the amount of product conveyed per mixing element. Similarly, the volume between the mixing elements can be varied, or the filling speed adjusted, to achieve the desired effect.

[0055] According to a further embodiment, several dynamic mixers can also be arranged in the outlet direction R, coupled in particular via a gearbox or a power transmission element. The dynamic mixers 5 can also be coupled to one another via mutual engagement. Alternatively, several drives can be provided. Dynamic speed control is also advantageous. A combination with a weighing flap / drop flap is possible. Since the dynamic mixer is designed as an attachment to a metering valve or a filling pipe, i.e., a pipe outlet of the filling machine, it can be easily replaced or retrofitted, which is particularly advantageous for cleaning purposes. Intrinsic safety is also ensured. Advantageously, this results in an actively driven dynamic mixing function.

Claims

Claims 1. Filling machine (1) for filling granular food products (12) with a conveying unit (23) which conveys the food product (12) to a product outlet (17), characterized in that a dynamic mixer (5) is arranged in front of the product outlet (17).

2. Filling machine (1) according to claim 1 , characterized in that the dynamic mixer (5) is arranged either at the end of a filling tube (2) or at the end of a metering valve (3).

3. Filling machine (1) according to claim 1 or 2, characterized in that the dynamic mixer (5) is designed as an attachable attachment, in particular on the metering valve (3) or filling tube (2).

4. Filling machine (1), characterized in that the dynamic mixer (5) is detachably connected to the metering valve (3) or the filling tube (2) via a connecting device (19).

5. Filling machine (1) according to at least one of claims 1-4, characterized in that the dynamic mixer (5) has a mixer housing (6) in which one or preferably several mixing elements (7) are rotatably mounted about an axis of rotation (D).

6. Filling machine (1) according to claim 5, characterized in that the dynamic mixer further comprises a drive (8) to drive a shaft (13) with the mixing element(s) (7).

7. Filling machine (1) according to at least one of claims 1-6, characterized in that the drive (8) is a compressed air motor (8).

8. Filling machine (1) according to at least one of claims 1-7, characterized in that the dynamic mixer (5) is designed as a paddle wheel mixer or as a paddle mixer and preferably has one or more mixer shafts on which one or more mixing elements (7) are arranged.

9. Filling machine (1) according to at least one of claims 1-8, characterized in that the dynamic mixer (5) has a shaft (13) with at least one, preferably several, flexible mixing elements (7) distributed around the circumference.

10. Filling machine (1) according to claim 9, characterized in that the flexible mixing elements (7) are made of at least one of the following materials: thermoplastic elastomers, natural rubber, silicones, polyurethanes, synthetic or natural elastomers (SBR, NBR, EPDM, FKM).

11. Filling machine (1) according to at least claim 5, characterized in that the action area (A) of the dynamic mixer, in particular the orbit of the mixing element(s), is adjacent to the product outlet.

12. Method for filling granular food products (12), in particular with a filling machine according to at least one of claims 1-11, characterized in that the conveying unit of the filling machine (1) conveys the food product into a dynamic mixer (5) which loosens the food product before it is ejected from a product outlet (17).

13. Method according to claim 12, characterized in that the granular food product is ejected in portions, in particular via a metering valve (3) or the intermittent drive of a conveyor system.

14. Method according to one of claims 12 or 13, characterized in that the food product is compacted by the conveying system and loosened by the dynamic mixer, wherein the dynamic mixer is in particular driven by a drive and preferably the degree of loosening is adjusted by the rotational speed of the dynamic mixer.

15. Method according to at least one of claims 12-14, characterized in that the food product is filled via the conveying system into a filling tube (2) or a metering valve housing (4) and pushed into the action area of ​​the dynamic mixer, where it is captured by the mixing elements (7) of the dynamic mixer rotating about a rotary axis D, loosened and conveyed to the product outlet (17).

16. Method according to at least one of claims 12-15, characterized in that a certain production quantity is ejected, after which the conveying unit stops and / or the metering valve closes, after which the dynamic mixer is driven for a certain overrun time, in particular 0.1 - 2 seconds and removes the entire filling medium from the mixer housing (6).

17. Method according to at least one of claims 12 - 16, characterized in that the food product is accelerated in the dynamic mixer.

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