METHOD AND DEVICE FOR FILLING AN OPEN CONTAINER

Abstract

The invention relates to a method and to a device for filling a container (2) open at the top with a flowable product, in particular with coffee powder or with milk powder, using a filling head (3) placed onto the container (2) in gas-tight manner, wherein the filling head (3) has a filling channel (30) and a gas channel (32), wherein the container (2) is received in a gas-tight jacketing (6) which adjoins the filling head (3) and/or the container (2) in sealing manner at least in a filling position in order to provide a gas-tightly closed gap (62) between the jacketing (6) and an outer container wall; wherein the filling channel (30) has a free end (300) which projects into the container (2) with an immersion depth in the filling position; wherein negative pressure is generated inside the container (2) and in the gap (62) in the filling phase for a product discharge; wherein the negative pressure inside the container (2) effects a product discharge via the filling channel (30) up to a filling level at least substantially corresponding to the immersion depth; wherein after the filling phase a gas supply to the container (2) and to the gap (62) takes place in a gassing phase; wherein an inert gas is supplied at least to the container (2) the gassing phase; and wherein a fill weight of the container (2) is determined and compared with a target weight after the filling phase and before the gassing phase, with topping up taking place if the determined fill weight is below the target weight.

Claims

1. A method for filling a container open at the top with a flowable product, in particular with coffee powder or with milk powder, using a filling head that is gas-tightly placed onto the container, wherein the filling head has a filling channel and a gas channel, wherein the container is received in a gas-tight jacketing which adjoins the filling head and/or the container in sealing manner at least in the filling position in order to provide a gas-tightly closed gap between the jacketing and an outer container wall, wherein the filling channel has a free end which projects into the container with an immersion depth in the filling position, wherein negative pressure is generated inside the container and the gap in a filling phase, wherein the negative pressure inside the container effects a product discharge via the filling channel up to a filling level corresponding at least substantially to the immersion depth, and wherein after the filling phase gas is supplied to the container and to the gap in a gassing phase, wherein an inert gas is supplied at least to the container in the gassing phase, wherein after the filling phase and before the gassing phase a fill weight of the container is determined and compared with a target weight, wherein topping up takes place if the determined fill weight is below the target weight.

2. The method according to claim 1, wherein at least the filling channel of the filling head is moved relative to the container for topping up, so that the immersion depth of the free end into the container is reduced and a topping-up volume is created inside the container, wherein a gas-tight connection of the filling head to the container is maintained in particular during topping up.

3. The method according to claim 1, wherein a tare weight of the container is determined before the filling phase.

4. The method according to claim 1, wherein the container rests on a bottom element in the filling phase, wherein a load cell of the weighing device is provided at the bottom element.

5. The method according to claim 1, wherein negative pressure is generated up to a first pressure level in the filling phase, and before the gassing phase negative pressure up to a second pressure level below the first pressure level is generated for degassing the container in a degassing phase.

6. The method according to claim 1, wherein after the filling phase and before a gassing phase, a pressure level inside the container and the gap is kept at a constant pressure level in a rest phase for product settling, wherein topping up takes place before or after the rest phase or as an interruption of it.

7. A device for filling a container open at the top with a flowable product, in particular with coffee powder or with milk powder, comprising a filling head and a gas-tight jacketing receiving the container in the filling position; wherein the filling head comprises a filling channel having a free end and a gas channel having a container opening and a connection opening; wherein the free end of the filling channel projects into the container with an immersion depth in the filling position; wherein in the filling position gas is dischargeable out of the container and suppliable to the container via the gas channel; wherein the jacketing adjoins the filling head and/or the container in sealing manner at least in the filling position in order to provide a gas-tightly closed gap between the jacketing and the outer container wall; wherein a gap connection opening is provided; wherein gas is dischargeable out of the gap and gas is suppliable to the gap via the gap connection opening; wherein a control device is provided which is configured to connect fluidically the container and the gap to a negative pressure source in a filling phase such that negative pressure is generatable inside the container and the gap; wherein the negative pressure in the container effects a product discharge via the filling channel up to a filling level at least substantially corresponding to the immersion depth; wherein the control device is configured to connect fluidically the container and the gap to a gas source after the filling phase in a gassing phase such that a gas is suppliable to the container and the gap; wherein an inert gas is suppliable in the gassing phase at least to the container, wherein a weighing device is provided for determining a fill weight of the container, wherein the control device is further configured to determine a fill weight of the container after the filling phase and before the gassing phase and compare it with a target weight, and to effect topping up if the determined fill weight is below the target weight.

8. The device according to claim 7, wherein an actuator is provided which is configured to move at least the filling channel of the filling head relative to the container for topping up, in order to reduce the immersion depth of the free end into the container and to create a topping-up volume inside the container, wherein in particular the filling head is in sealing contact with the container during topping up.

9. The device according to claim 7, wherein the control device is configured to determine a tare weight of the container using the weighing device before the filling phase.

10. The device according to claim 7, wherein the weighing device comprises a load cell, wherein a bottom element is provided on which the container rests in the filling phase, and wherein the load cell is provided at the bottom element.

11. The device according to claim 7, wherein negative pressure is generatable up to a first pressure level in the filling phase, wherein after the filling phase and before the gassing phase the container and the gap are connectable fluidically to the negative pressure source using the control device in a degassing phase for degassing such that negative pressure is generatable up to a second pressure level below the first pressure level inside the container and the gap.

12. The device according to claim 7, wherein the control device is further configured to keep a pressure level in the container and the gap at a constant pressure level in a rest phase for settling of the product after the filling phase and before the gassing phase, wherein topping up can be effected before or after the rest phase or as an interruption of it.

13. A carousel comprising several positions distributed over the circumference and at each of which a device according to claim 7 is provided.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further advantages and aspects of the invention are revealed by the claims and by the following description of preferred exemplary embodiments, which are explained below with reference to the figures: The drawing shows in:

[0039] FIG. 1 an embodiment of a device for filling a container open at the top with a flowable product;

[0040] FIG. 2 a starting position of a method for filling a container open at the top with a flowable product;

[0041] FIG. 3 a first phase of the method for filling of the container open at the top, wherein the container is moved into a filling position;

[0042] FIG. 4 a second phase of the method, wherein the container is being filled;

[0043] FIG. 5 a third phase of the method, wherein a pressure level is kept constant to settle the product;

[0044] FIG. 6 a fourth phase of the method, wherein a pressure level is further lowered for degassing of the product;

[0045] FIG. 7 a fifth phase of the method, gassing of the container with an inert gas takes place;

[0046] FIG. 8 a sixth phase of the method, wherein bridging takes place at a filling channel by the application of a negative pressure;

[0047] FIG. 9 a seventh phase of the method, wherein the container is removed from the device; and

[0048] FIG. 10 a carousel with several devices for filling containers.

DETAILED DESCRIPTION OF THE EXAMPLES

[0049] FIG. 1 shows an embodiment of a device 1 for filling a container open at the top 2 with a flowable product, in particular with coffee powder or with milk powder.

[0050] The device 1 comprises a filling head 3 with a filling channel 30 having a free end 300 and with a gas channel 32. The gas channel 32 comprises a section surrounding the filling channel 30 in annular manner, at the free end of which section a container opening 320 is provided. A gas-permeable closure element 326 for product retention is provided at the container opening 320. The closure element 326 is for example a metal grille or a component made of a porous material.

[0051] In the embodiment shown, a section 301 of the filling channel 30, which adjoins the free end 300 with the outlet opening, is also designed gas-permeable, such that when a negative pressure is generated inside the gas channel 32 the flowable product can be drawn onto an inner wall of this section 301 of the filling channel 30 to form a bridge, as described further below.

[0052] The gas channel 32 shown has a first connection opening 321 for connection to a negative pressure source, not shown, and a second connection opening 322 for connection to a gas source, not shown. In a modified embodiment, only one connection opening is provided instead of the two connection openings 321, 322 and is connectable fluidically to the negative pressure source or to the gas source depending on the phase. A bypass opening 323, via which the gas channel 32 is connectable fluidically to the surroundings, is further provided on the gas channel 32.

[0053] In a filling position shown in FIG. 1, the container 2 adjoins the filling head 3 in gas-tight manner with a sealing element 4, such that gas is dischargeable out of the container 2 via the gas channel 32. For that purpose, the first connection opening 321 for example is connectable to a negative pressure source, not shown, such as a vacuum pump. Gas is also suppliable to the container 2 via the gas channel 32, wherein the second connection opening 322 is connectable to a gas source, not shown, in particular to an inert gas supply.

[0054] A bottom element 5, which supports the container 2 from underneath and which is movable relative to the filling head 3, as shown schematically by a double arrow, is provided in the example shown for movement of the container 2 relative to the filling head 3. In some embodiments, the device 1 is part of a carousel 8, shown in FIG. 10, with several positions 82, wherein the bottom element 5 is lifted relative to the filling head 3 when the carousel 8 is rotated, so that an upper open end of the container 2 contacts the filling head 3 in sealing manner. In another embodiment, the filling head 3 is lowered relative to the bottom element 5, such that an upper open end of the container 2 contacts the filling head 3 in sealing manner.

[0055] The device 1 comprises a weighing device 7, wherein a tare weight of the container 2 before filling and a fill weight of the container 2 after filling are determinable with the weighing device 7. The weighing device 7 comprises in the example, shown schematically, a load cell 70 provided at the bottom element 5.

[0056] The device 1 further comprises a gas-tight jacketing 6, which receives the container 2 in the filling position shown in FIG. 1. In the example shown, the jacketing 6 is designed in one piece with the filling head 3. The jacketing 6 is formed for example as a separate component and is connected undetachably in gas-tight manner to the filling head 3, for example by soldering, adhesion or welding, or connected detachably in gas-tight manner to the filling head 3 using sealing elements.

[0057] The jacketing 6 shown has an open lower end 60, which is sealable in gas-tight manner with the bottom element 5, for example via a seal 65. In this way a gap 62 sealed in gas-tight manner is provided between the jacketing 6 and an outer container wall. In other embodiments, the jacketing 6 is designed in one piece with the bottom element 5 and is connected detachably in gas-tight manner to the filling head 3 and/or to the container 2.

[0058] The gap 62 is connected to the gas channel 32 via a gap connection opening 64, so that gas is dischargeable from the gap 62 and gas is suppliable to the gap 62 via the gap connection opening 64. In other embodiments, the gap connection opening 64 is provided on the bottom element 5 and/or on a cover of the jacketing 6 that adjoins the filling head 3. The connection of the gap 62 to the gas channel 32 permits simultaneous degassing and gassing of an interior of the container 2 and of the gap 62 surrounding the container 2 using a common negative pressure source or a common gas source. In other embodiments, an additional negative pressure source and/or an additional gas source is provided for the gap 62.

[0059] A control device 9 is provided for a phase-dependent connection of the gas channel 32 to the negative pressure source or to the gas source. The control device 9 is coupled wired or wirelessly to the weighing device 7 for exchanging data, wherein the data determined by the weighing device 7 is evaluated by the control device 9 and if a fill weight determined falls short of a target weight.

[0060] In some embodiments the control device 9 comprises an electronic control unit. A connection of the gas channel 32 to the negative pressure source or to the gas source is effected by the electronic control unit, wherein valves provided at the connection openings 321, 322 can be opened or closed by the control unit.

[0061] In other embodiments, the control device comprises a mechanical control unit with a setting disc, wherein the setting disc and the filling head are movable relative to one another. Depending on a positioning of the filling head 3 relative to the setting disc, the connection openings 321, 322 are connected to the negative pressure source or to the gas source or disconnected therefrom and in particular closed by the setting disc. The setting disc is further designed such that depending on a positioning of the filling head 3 relative to the setting disc, the bypass opening 323 is opened for a fluidic connection of the gas channel 32 to the surroundings, or closed for its disconnection. The use of a mechanical control device permits a valve-free design for degassing and/or gassing.

[0062] A method for filling the container 2 using the device 1 is described in the following with reference to FIGS. 2 to 10.

[0063] FIG. 2 shows a starting position of the method, wherein the filling head 3 is arranged above the container 2 at a distance therefrom. A connection to the negative pressure source via the first connection opening 321 and a connection to the gas source via the second connection opening 322 are interrupted, as shown schematically by crosses. The gas channel 32 may be connected to the surroundings via the bypass opening. The connection is also interrupted in other embodiments.

[0064] FIG. 3 shows schematically a first phase of the method, in Zone Il in FIG. 10, wherein the container 2 is lifted in the direction of the filling head 3 by the bottom element 5 and moved into the filling position. In the filling position, the open end of the container 2 is sealed in gas-tight manner by the filling head 3. The container 2 is inserted into the jacketing 6 and the open lower end of the jacketing 6 is sealed by the bottom element 5. The movement of the bottom element 5 in the direction of a filling head 3 arranged at a constant level is advantageous for simplicity in the design of the gas supply and gas discharge. Designs are however also conceivable in which the filling head 3 is lowered in the direction of the bottom element 5. After lowering of the filling head 3 onto the container 2, a tare weight of the container 2 is determinable by the weighing device 7. Determining the tare weight is performed in Zone III according to FIG. 10. In some embodiments, any weight forces applied to the weighing device 7 by the filling head 3 are also determined and are taken into account in the tare weight of the container 2.

[0065] FIG. 4 shows schematically a second phase of the method, the filling phase, in Zone IV in FIG. 10, wherein the container 2 is filled. For that purpose, the gas channel 32 is connected via the first connection opening 321 to a negative pressure source, not shown. Negative pressure is generated inside the container 2 or the gap 62 using the negative pressure source, via the container opening 320 of the gas channel 32 and via the gap connection opening 64 respectively. The connection of the gas channel 32 to the surroundings via the bypass opening 323 remains open here, so that negative pressure is set at a first pressure level. The negative pressure inside the container has the effect that the flowable product is drawn into the container 2 via the filling channel 30. The gas-permeable closure element 326 at the container opening 320 prevents the product getting into the gas channel 32.

[0066] Filling takes place up to a maximum filling level shown in FIG. 5, corresponding to an immersion depth of the free end 300 of the filling channel 30 into the container 2.

[0067] After completion of the filling phase, a fill weight of the container 2 is determinable by the weighing device 7, in Zone V in FIG. 10. In some embodiments, any weight forces applied to the weighing device 7 by the filling head 3 are also determined and are also taken into account in the fill weight of the container 2. In some embodiments, a difference in the pressure is determined when determining the fill weight in comparison to a pressure when determining the tare weight, and taken into account during determination.

[0068] The fill weight can be compared to a target weight using the control device 9 (see FIG. 1). In some embodiments, the target weight is a target net weight of the filled product, wherein the determined tare weight is subtracted from the determined fill weight or the determined tare weight is added to the target weight for the comparison.

[0069] FIG. 5 shows a third phase of the method after the end of product filling, also referred to as the rest phase, in Zone VI in FIG. 10, wherein a pressure level is kept constant for settling of the product inside the container 2. The connection opening 321 remains open in an embodiment.

[0070] If the comparison of the fill weight with the target weight in Zone V according to FIG. 10 indicates that the fill weight is below the target weight, topping up is possible before, during or after the rest phase, wherein for that purpose the filling channel 30 is moved relative to the container 2 using an actuator 90 shown schematically in the example shown, so that an immersion depth of the first end into the container 2 is reduced and a topping-up volume is created inside the container 2 in this way. In the example shown, the entire filling head 3 is moved upwards for topping up, as shown schematically by an arrow in FIG. 5. This movement during topping up is within a tolerance range, so that during a movement of the filling head 3 relative to the container 2 the gas-tight contact of the filling head 3 with the container 2 and also a gas-tight connection of the bottom element 5 to the jacketing 62 are maintained. In other embodiments, only the filling channel 30 is moved relative to the container 2 using an actuator. In yet other embodiments, the container 2 is alternatively or additionally moved relative to the filling channel 30 or to the entire filling head 3 using an actuator.

[0071] FIG. 6 shows a fourth phase of the method, also referred to as degassing phase, in Zone VII in FIG. 10, wherein a pressure level is further lowered for degassing of the product filled into the container 2. For that purpose, the bypass opening 323 is closed in the example shown, so that in the case of a connection of the gas channel 32 to the negative pressure source via the first connection opening 321 a second pressure level, which is below the first pressure level during the product discharge (cf. FIG. 4), is generated inside the container 2 and the gap 62 surrounding the container. A simultaneous pressure reduction inside the container 2 and the gap 62 around the container 2 prevents the container 2 from collapsing due to an applied negative pressure.

[0072] FIG. 7 shows a fifth phase of the method, also referred to as gassing phase, in Zone VIII in FIG. 10, wherein the container 2 is gassed with an inert gas. For that purpose, the first connection opening 321 is disconnected from the negative pressure source and the second connection opening 322 is connected fluidically to the gas source. Since the gap 62 is connected fluidically to the gas channel 32 via the gap connection opening 64, the gap 62 too is gassed with the inert gas. In other embodiments, a different gas than that in the container 2 is supplied to the gap 62 via a separate gas source.

[0073] FIG. 8 shows a sixth phase of the method, in Zone IX in FIG. 10, wherein negative pressure is again applied for forming a bridge at an outlet opening 300 of the filling channel 30.

[0074] Formation of a stable arch-like structure in the region of an outlet opening 300 of the filling channel due to adhesive forces between individual particles of the product is referred to as bridging in connection with the application.

[0075] Application of the negative pressure for bridging is achieved via the gas channel 32 used for degassing and gassing in the example shown. The first connection opening 321 is again connected fluidically to the negative pressure source. Due to the applied negative pressure, particles of the product present in the filling channel 30 are drawn onto the gas-permeable section 301 of the filling channel 30. As a result, a so-called bridge forms at the outlet opening of the filling channel 30, preventing a further product discharge when the container 2 is separated from the filling head 3. This allows filler valves, flaps or the like to be dispensed with at the filling head 3. The negative pressure is applied for a sufficiently short period for bridging such that drawing of the product out of the container 2 is at least reduced to a tolerable extent.

[0076] In an alternative embodiment, not shown, a chamber surrounding the gas-permeable section 301 is provided, via which negative pressure for bridging is applicable to the gas-permeable section 301. In an embodiment, the chamber has a connection opening, not opening into the gas channel 32, for a negative pressure source. The chamber is degassed or evacuated via the separate connection opening, without the product being drawn out of the container 2 via a container opening of the gas channel.

[0077] FIG. 9 shows a seventh phase of the method, in Zone X in FIG. 10, wherein the container 2 is removed from the device 1. To do so, the bottom element 5 with the container 2 set thereon is lowered relative to the filling head 3. The container 2 can then be supplied to a closing device, not shown.

[0078] The device 1 is, in advantageous embodiments, at a position of a carousel with several positions, each having one device 1 according to FIGS. 1 to 9.

[0079] FIG. 10 shows a carousel 8, schematically in a plan view. The carousel 8 has a turntable 80 rotating about a rotary axis A and several positions 82, 24 in number in the example shown, distributed evenly over the circumference, wherein one device 1, each with a filling head 3 (cf. FIGS. 1 to 9), is provided at each position 82 according to FIGS. 1 to 9. The turntable 80 can be rotated about the rotary axis A for a movement of the positions 82 in a timed or continuous manner. For loading and unloading, inlet and outlet wheels 84, 86 are provided in the example shown, which rotate synchronously with the carousel 8 in order to transfer one container 2 (cf. FIGS. 1 to 9) to a position 82 or to remove a container 2 from a position 82 respectively. Other devices for loading and unloading are however also conceivable. Loading and unloading takes place in a Zone I in FIG. 10.

[0080] A carousel 8 permits a continuous process, wherein the various process steps of the method according to FIGS. 2 to 9 are performable distributed over the circumference of the carousel 8. In the example shown, ten Zones I to X are provided on the carousel 8 for that purpose.

[0081] In a first Zone I of the carousel 8, loading of the carousel 8 with containers 2 or unloading takes place. The containers 2 supplied to the carousel 8 are transported after loading, by rotation of the carousel 8, and pass through further Zones Il to X in the example shown.

[0082] In a second Zone Il following the first Zone I in a rotation direction indicated by an arrow, the bottom elements 5 with the containers 2 are lifted in the direction of the filling head 3 as shown in FIG. 2. The positions 82 are, during lifting of the container 2 in the direction of the filling head 3, in each case closed off from the surroundings using the jacketing 6 connectable to the bottom element 5 in sealing manner (cf. FIGS. 2 and 3).

[0083] Then a tare weight of the container 2 with the filling head 3 set thereon is determined in Zone III. The Zone III is limited to exactly one angle setting of the position 82 in the case of a timed movement of the carousel, or to a comparatively small angle range in the case of a continuous movement. In some embodiments, the tare weight is determined using the weighing device 7 provided at the position 82. In other embodiments, a weighing device is provided stationarily at the carousel 8.

[0084] After determining the tare weight, the container 2 is filled in Zone IV, as shown in FIG. 4. After filling, a fill weight of the container 2 with the filling head 3 set thereon is determined in Zone V. Zone V is also limited to exactly one angle setting of the position 82 in the case of a timed movement of the carousel, or to a comparatively small angle range in the case of a continuous movement. In some embodiments, the fill weight is determined using the weighing device 7 provided at the position 82. In other embodiments, a weighing device is provided stationarily at the carousel 8.

[0085] This is followed by settling of the filled product in Zone VI as shown schematically in FIG. 5. If comparison of the determined fill weight with a target weight shows that topping up is required, this topping up also takes place in Zone VI.

[0086] In the following Zone VII, degassing as shown in FIG. 6 takes place. In a following Zone VIII, gassing with an inert gas as shown in FIG. 7 takes place.

[0087] In Zone IX, negative pressure is again applied for bridging at an outlet opening of the filling channel 30 (cf. FIG. 8), as shown schematically in FIG. 8.

[0088] In a final Zone X, the bottom elements 5 with the containers 2 are, as shown in FIG. 9, lowered relative to the filling head 3, so that the containers 2 are then removable from the carousel 8.

[0089] Finally, the containers are ejected in the first Zone I and supplied for example to a closing device, not shown, for sealing the containers.

[0090] The carousel 8 is also used here as a mechanical control device, wherein a fixed setting disc, not visible in FIG. 10, is provided on the carousel 8. With the rotation of the turntable 80 of the carousel 8, the devices 1 provided at the positions 82 are moved relative to the setting disc, wherein the connection openings 321, 322 are connected to the negative pressure source or to the gas source or are disconnected therefrom, depending on a positioning of the filling head 3 of the respective device 1 relative to the setting disc. The setting disc is further designed here such that the bypass opening 323 is opened for a fluidic connection of the gas channel 32 to the surroundings or closed for its disconnection, depending on a position of the filling head 3 relative to the setting disc. The setting disc has the effect in this way that negative pressure with a first pressure level is generated inside the container 2 and the gap 62 for filling the containers in Zone IV, and negative pressure up to a second pressure level below the first pressure level is generated inside the container 2 and the gap 62 for degassing in Zone VII.