Filling valve for filling a liquid product into containers and filling machine

Abstract

A filling valve (1) for filling a liquid product (2) into containers (3) and a filling machine equipped with it are described. The filling valve comprises a valve seat (4) and an associated closure element (5) for opening / closing a product path (7) on the outlet side, the closure element being centrally located in the product path. The filling valve further comprises a pressurization gas path (8) extending upwards through the closure element and separately from the product path, and a relief gas path (9) opening into the product path downstream of the valve seat. The additional provision of a connecting path (10, 11) for pressure equalization between the pressurization gas path and the relief gas path prevents both product losses through the relief gas path and the introduction of unwanted moisture from the relief gas path into the pressurization gas path.

Description

[0001] The invention relates to a filling valve for filling a liquid product into containers according to the preamble of claim 1 and to a filling machine equipped therewith.

[0002] A generic filling valve is known, for example, from DE 10 2013 109 430 A1.

[0003] Such filling valves are suitable for filling liquid products. Filling processes are terminated after reaching a target product fill level measured by short-circuit probes or after reaching a product flow rate measured in the product inlet. In this type of filling, separate gas paths are typically used for a pre-pressurizing gas and the relief gas discharged from the headspace to prevent contact between the pre-pressurizing gas and the relief gas. This allows for "dry pre-pressurizing" of the containers.

[0004] For the relief gas, an opening with an adjoining relief gas channel is formed in the filling valve below its outlet-side product valve, through which the relief gas can escape from the head space of the respective container into a relief channel arranged centrally on the filling machine.

[0005] The disadvantage here is that the product not only flows past the relief opening as intended during the filling process, but also partially enters it and is lost through the relief gas channel during the relief process toward the end of the filling process. Furthermore, product residues remaining in the area of the relief hole after the filling process can be drawn into a vacuum channel branching off from the relief gas channel during subsequent suction for the subsequent filling process and discharged from a connected vacuum pump of the filling machine. This typically results in a total loss of one to two milliliters of product per filling process and filled bottle.

[0006] There is therefore a need for improved filling valves and filling machines equipped with them.

[0007] The stated object is achieved with a filling valve according to claim 1. Accordingly, it is designed for filling a liquid product into containers, in particular bottles, and comprises a valve seat and an associated closure part for opening / closing a product path carrying the product on the outlet side, wherein the closure part is arranged centrally in the product path. Furthermore, the filling valve comprises a pressurizing gas path extending upwardly through the closure part and separate from the product path, and a relief gas path opening into the product path downstream of the product and / or below the valve seat.

[0008] According to the invention, the filling valve further comprises a connecting path formed in addition to the product path for pressure equalization between the clamping gas path and the relief gas path.

[0009] It has surprisingly been found that the product flowing through the valve seat seals the area of the product path above it from the relief gas path and the liquid column of the product present in the product path causes such a high static differential pressure in the area of the mouth of the relief gas channel that the product is pushed into the mouth and a section of the relief gas channel.

[0010] According to the invention, this is counteracted by the additional connecting path, which enables pressure equalization between the clamping gas path and the relief gas path. This results in the product flowing essentially completely past the opening of the relief gas path. Consequently, no product is lost during relief and / or extraction.

[0011] The connection path for pressure equalization is therefore open at least when the product valve is open, i.e., while product is flowing through the product path. When the product valve is closed, i.e., the product flow is blocked, the connection path can be closed, since pressure equalization at the outlet of the relief gas path is then no longer required.

[0012] The valve seat and the closure part form the actual product valve. The closure part can be raised and lowered in a conventional manner using a valve rod and actuator, spring tension, or similar means.

[0013] The clamping gas path runs, for example, in the valve rod, a return gas pipe or the like and through an upper section of the filling valve.

[0014] Preferably, the filling valve further comprises a product inlet that opens into the product channel below the connecting path. This reliably prevents product from entering the pressurizing gas channel via the connecting path.

[0015] According to the invention, the connecting path runs through a valve block for connecting the clamping gas path to a preload valve and for connecting the relief gas path to a relief valve. The connecting path can be provided in a valve block in a relatively simple manner in the form of a connecting bore.

[0016] The connecting path can be formed by a permanently open connecting channel. Pressure equalization is then possible with very little equipment.

[0017] Preferably, the connecting channel connects sections of the clamping gas path and the relief gas path at an angle of no more than 45° to the vertical, and in particular vertically extending sections. This further reduces the likelihood of unwanted moisture entering the clamping gas path via the connecting channel.

[0018] The connection path can run via a separately controllable shut-off device, typically a PTFE bellows valve. This allows for timed control of pressure equalization and, if necessary, more flexible use of the filling valve for different filling processes.

[0019] Preferably, the clamping gas path runs longitudinally through a valve rod that adjoins the closure part at the top. The clamping gas path can also be used as a return gas path, as can the pre-tensioning valve as a return gas valve. A short-circuit probe and / or an associated signal line can be arranged in the valve rod, particularly within the clamping gas path.

[0020] Preferably, a vacuum gas path connected to a vacuum valve branches off from the relief gas path. The section of the relief gas path between the branch and the product path can then be used alternately for relieving the headspace at the end of the filling process and for evacuating containers at the beginning of the filling process. The initial evacuation is known to be performed for products sensitive to oxygen from the ambient air.

[0021] Preferably, the vacuum gas path branches off from the relief gas path below the connecting path. This simplifies pressure equalization and also prevents product residues from being drawn into the vacuum gas path during subsequent suction of containers to be filled.

[0022] The stated object is also achieved with a filling machine comprising a rotor and filling valves attached thereto according to at least one of the embodiments described above.

[0023] Preferably, the filling machine then further comprises an annular pre-pressurizing gas channel arranged on the rotor for providing pre-pressurizing gas for the containers through the filling valves.

[0024] Preferably, the filling machine then further comprises an annular relief channel arranged on the rotor for receiving relief gas passed from the containers through the filling valves.

[0025] Preferably, the filling machine then further comprises a vacuum channel arranged on the rotor and in particular annular in shape for providing a vacuum for suctioning the containers through the filling valves.

[0026] A preferred embodiment of the invention is illustrated in the drawings. Figure 1 shows a schematic representation of a filling valve with gas paths to central gas channels of a filling machine; and Figure 2 shows a detailed representation of the outlet area of the filling valve with a bottle attached.

[0027] As the Figure 1 As can be seen in a schematic representation, the filling valve 1 for filling a product 2 into containers 3, in particular bottles, comprises at its outlet area 1a a valve seat 4 and an associated closure part 5 as components of a product valve 6 for the outlet-side opening / closing of a product path 7 for the product 2 running through the filling valve 1.

[0028] The closure part 5 is arranged centrally in the product path 7 in a known manner, in particular coaxially with the valve seat 4, and can be pressed downward against it, for example by means of mechanical spring preload, in order to close the product path 7 downwards. In the opposite direction, the closure part 5 can be raised against the spring preload, for example by a conventional control cylinder, in order to open the product path 7 for the product 2 and allow it to flow into the container 3.

[0029] For filling carbonated products, a pressurized gas path 8 running through the closure part 5 from top to bottom is formed centrally in the filling valve 1, separate from the product path 7.

[0030] Downstream of the valve seat 4, at least one relief gas path 9 flows into the product path 7.

[0031] For pressure equalization between the clamping gas path 8 and the relief gas path 9, a connecting path 10 is also provided, which can be designed, for example, as a permanently open channel.

[0032] Alternatively, a temporarily closable connecting path 11 can be formed between the clamping gas path 8 and the relief gas path 9. This is shown in the Figure 1 indicated by dashed lines. The temporary closure of the connecting path 11 is achieved, for example, by means of a separately controllable shut-off device 12, which is in particular a PTFE bellows valve. The connecting path 11 is open at least when the product valve 6 is open and can also be closed when the product valve 6 is closed.

[0033] Furthermore, a known product inlet 13 for the product 2 is formed in the filling valve 1. Due to the height difference between the product inlet 13 and the opening 9a of the relief gas path 9 into the product path 7, a local static overpressure would actually result in the relief gas path 9, which is, however, balanced by the connecting path 10, 11 to the pressure gas path 8. This prevents the product 2 flowing along the opening 9a of the relief gas path 9 from being forced into the relief gas channel 9.

[0034] A vacuum gas path 14 branches off from the relief gas path 9, through which ambient air and the oxygen contained therein can be sucked out of the containers 3 at the beginning of the respective filling process.

[0035] In the Figure 1For better understanding, a pre-pressurization gas 15 flowing through the pressurization gas path 8 into the containers 3, a return gas 16 returned through the pressurization gas path 8, a relief gas 17 discharged through the relief gas path 9 and an extraction gas 18, which is essentially ambient air and flows first through the relief gas path 9 and finally through the vacuum gas path 14 branching off from it, are shown schematically in the form of block arrows.

[0036] The filling valve 1 preferably comprises a valve block 19 with a preload valve 20 for opening / closing the pressurizing gas path 8, a relief valve 21 for opening / closing the relief gas path 9 and a vacuum valve 22 for opening / closing the vacuum gas path 14. The valves 20 to 22 are preferably PTFE bellows valves.

[0037] The preload valve 20 can also be referred to as a return gas valve or preload and return gas valve, since preload gas 15 can flow in and return gas 16 can flow out alternately through this and the subsequent preload gas path 8.

[0038] Via the valves 20 to 22, the clamping gas path 8 is connected to a clamping gas channel 23, the relief gas path 9 is connected to a relief channel 24 and the vacuum gas path 14 is connected to a vacuum channel 25.

[0039] The pressurizing gas channel 23, the relief channel 24, and the vacuum channel 25 are designed as annular channels and are arranged on a rotor 26 (indicated only schematically) of a filling machine 100 of rotating design. A plurality of filling valves 1 are then arranged circumferentially distributed on the rotor 26, which rotates continuously about a vertical axis 26a, in a known manner.

[0040] With the exception of the described pressure equalization in the filling valves 1, the filling machine 100 may have a known design, the features of which are therefore not described further.

[0041] The connecting path 10 is preferably designed as a cross connection between two sections 8a, 9b of the clamping gas path 8 and the relief gas path 9, each extending at an angle of no more than 45° to the vertical and, in particular, as schematically illustrated, essentially vertically. Such a cross connection is comparatively easy to establish by means of a bore in the valve block 19 and further minimizes the risk of moisture entering the clamping gas path 8 from the relief gas path 9.

[0042] The sections 8a, 9b of the clamping gas path 8 and the relief gas path 9 connected to the connecting path 10 are preferably located above the branching point of the vacuum gas path 14 from the relief gas path 9 and / or above the product inlet 13. Therefore, the introduction of moisture from the vacuum gas path 14 into the clamping gas path 8 by means of extracted ambient air can also be avoided.

[0043] The Figure 2 shows a concrete design of the outlet area 1a of the filling valve 1 with the valve seat 4 and the closure part 5 of the product valve 6. Accordingly, the closure part 5 preferably tapers downwards and comprises, for example, a sealing surface 5a which cooperates sealingly with the valve seat 4.

[0044] The opening 9a of the relief gas path 9 into the product path 7 is located in the outlet area 1a downstream of the valve seat 4, i.e., below the sealing surface 5a resting on the valve seat 4. Therefore, the opening 9a cannot be closed by the closure part 5. Nevertheless, the closure part 5 can, as shown, extend into the area of the opening 9a to optimize the flow behavior of the product 2.

[0045] In the Figure 2 The mouth area 3a of a container 3, which is in particular a bottle, can also be seen. The mouth area 3a rests against the filling valve 1 in a manner known in principle, with the aid of a centering and sealing aid 27.

[0046] In the example of Figure 2The filling process is controlled by a short-circuit probe 28, which is only partially indicated. The product valve 6 is then closed depending on a fill level measured by the short-circuit probe 28. The product valve 6 can be actuated in different ways, for example by a pneumatically driven control cylinder arranged above the product inlet 13 in the filling valve 1.

[0047] The clamping gas path 8 and the short-circuit probe 28 run inside a valve rod 29, which is connected to the closure part 5 at the top and can be actuated, for example, by a pneumatic control cylinder 30 in a known manner.

[0048] During filling operation, a container 3 which is sealingly attached to the filling valve 1 from below is, for example, first sucked out by opening the vacuum valve 22 to the vacuum channel 25 through the relief gas path 9 and the vacuum gas path 14.

[0049] After closing the vacuum valve 22, the container 3 can be pre-pressurized to a filling overpressure by opening the pre-pressurization valve 20 with the pre-pressurization gas 15 in a manner known per se through the pre-pressurization gas channel 8.

[0050] After opening the product valve 6, the product 2 standing above it as a liquid column can flow into the container 3, whereby a pressure equalization between the clamping gas path 8 and the relief gas path 9 through the open connecting path 10, 11 prevents the product 2 flowing along the mouth 9a of the relief gas path 9 from penetrating into the relief gas path 9.

[0051] Return gas 16 displaced from the container 3 when the product 2 flows in can flow out through the clamping gas path 8.

[0052] After closing the pre-tensioning valve 20 for the tensioning gas path 8, the product 2 flows at a reduced speed, whereby the head space 3a of the container 3 is relieved by opening the relief valve 21 through the relief gas path 9 into the relief channel 24.

[0053] At least while the product 2 flows into the container 3, the pressure equalization between the relief gas path 9 and the clamping gas path 8 is made possible by the connecting path 10, 11 in such a way that entry of the product 2 from the area of the product path 7 into the relief gas path 9 is reliably avoided.

[0054] After completion of the filling process and attachment of another container 3 for subsequent filling and during the initial suction of ambient air, no residues of the product 2 can be withdrawn from the relief gas path 9 through the vacuum gas path 14.

[0055] Thus, product losses can be significantly reduced and even largely avoided, even under the condition of a "dry preload" of the containers 3, compared to known filling valves.

Claims

1. A filling valve (1) for filling a liquid product (2) into containers (3), comprising: - a product valve (6) with a valve seat (4) and an associated closure part (5) for opening / closing a product path (7) for the product (2) on the outlet side, wherein the closure part (5) is arranged centrally in the product path (7); - a purge gas passage (8) extending upward through the closure part (5) and separated from the product path (7); - a relief gas path (9) opening into the product path (7) downstream of the valve seat (4); and - a connecting passage (10, 11) formed in addition to the product path (7) for pressure equalization between the purge gas passage (8) and the relief gas passage (9), characterized in that the connecting passage (10, 11) extends through a valve block (19), which valve block (19) is designed to connect the purge gas path (8) via a pre-pressurization valve (20) to a purge gas channel (23) designed as a ring channel and to connect the relief gas passage (9) via a relief valve (21) to a relief channel (24) designed as a ring channel, and in that the connecting passage (10, 11) is designed as a permanently open channel or as a channel that can be temporarily closed between the purge gas passage (8) and the relief gas passage (9) in order to open the connecting passage (11) at least when the product valve (6) is open.

2. The filling valve according to claim 1, further comprising a product inlet (13) which opens into the product path (7) below the connecting path (10, 11).

3. The filling valve according to one of claims 1 to 2, wherein the connecting channel (10, 11) connects two sections (8a, 9b) of the purge gas passage (8) and the relief gas passage (9) which are at an angle of at most 45° to the vertical and in particular are perpendicular.

4. The filling valve according to one of claims 1 to 2, wherein the connecting path (11) runs via a separately controllable shut-off device (12), which is in particular a PTFE bellows valve.

5. The filling valve according to at least one of the previous claims, wherein the purge gas passage (8) also runs longitudinally through a valve rod (29) connected to the closure part (5) at the top.

6. The filling valve according to at least one of the previous claims, wherein a vacuum gas passage (14) connected to a vacuum valve (22) branches off from the relief gas passage (9).

7. The filling valve according to claim 6, wherein the vacuum gas passage (14) branches off from the relief gas passage (9) below the connecting passage (10).

8. A filling machine (100) with a rotor (26) and filling valves (1) attached thereto according to at least one of the preceding claims.

9. The filling machine according to claim 8, further comprising a ring-shaped pre-pressurizing gas channel (23) arranged on the rotor (26) for supplying pre-pressurizing gas (15) to the containers (3) through the filling valves (1).

10. The filling machine according to claim 8 or 9, further comprising a ring-shaped relief channel (24) arranged on the rotor (26) for receiving relief gas (17) conducted from the containers (3) through the filling valves (1).

11. The filling machine according to one of claims 8 to 10, further comprising a vacuum channel (25) arranged on the rotor (26) and in particular ring-shaped, for providing a vacuum for sucking the containers (3) through the filling valves (1).

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