CN111170250A

CN111170250A - Method for counter-pressure filling of containers and filling system for counter-pressure filling machine

Info

Publication number: CN111170250A
Application number: CN201911088662.8A
Authority: CN
Inventors: 霍尔格·穆勒; 于尔根·泽尔纳
Original assignee: Krones AG
Current assignee: Krones AG
Priority date: 2018-11-09
Filing date: 2019-11-08
Publication date: 2020-05-19
Anticipated expiration: 2039-11-08
Also published as: EP3650402B1; JP2020075766A; EP3650402A1; DE102018219119A1; CN111170250B; JP7435952B2; SI3650402T1

Abstract

The invention provides a method for filling a container (140) with a liquid under increased pressure, wherein, before a filling process is started, a substantially gas-tight contact is established between a container opening (145) of the container (140) to be filled and an outlet opening (230) of a filling element (200), wherein, after the filling process is completed, the substantially gas-tight contact is temporarily released at least once to achieve at least partial decompression of the filled container before the container opening (145) is finally separated from the outlet opening (230).

Description

Method for counter-pressure filling of containers and filling system for counter-pressure filling machine

Technical Field

The present invention relates to a method for filling containers with a liquid under increased pressure, and to a filling system of a counter-pressure filling machine for carrying out the method.

Background

When filling liquids into containers under pressure, for example when filling carbonated products and beverages into bottles or cans, the mouth of the container to be filled is pressed substantially gas-tightly against the outlet of the filling element used during the filling process, so that the filling product can be introduced into the container under increased pressure.

The container to be filled can be lifted by means of a suitable moving device and pressed against the filling device, i.e. against the outlet of the filling element used, as described, for example, in german unexamined and first published DE4134446a 1. Alternatively, the filling element can be lowered to the mouth of the container until an airtight contact is established, as described, for example, in german unexamined and first published DE4101891a 1. By means of appropriately designed sealing and centering means, it can be ensured that the outlet opening is positioned precisely on the mouth of the container to be filled and remains substantially airtight during the filling process.

Prior to filling, the container can be pre-purified with a purge gas, such as nitrogen or carbon dioxide, especially in the case of oxygen-sensitive products. By filling the liquid under increased pressure, the pressure in the container also continuously rises. Alternatively or in addition, the container can be preloaded to a preload pressure with a pressure gas (in particular carbon dioxide) via a pressure gas channel, whereafter the container is filled at a pressure equal to the product (in particular carbonated product).

After the container has been filled with the liquid or product, the pressurized headspace of the container is depressurized via a depressurization path with an associated depressurization valve. The pressure is substantially reduced to ambient pressure. After the filling element has been released, it is removed from the mouth of the container or the container is lowered, so that the filled container can be removed from the filling machine (e.g. from the filling machine rotating equipment).

For example, in fig. 1a filling system of a counter-pressure filling machine as known in the prior art is shown. The filling element 100 is arranged on the holding device 152 in a height-adjustable manner. In the position shown in the figures, the filling element 100 together with the outlet opening 130 of the pressure sleeve 128 has been lowered to the mouth 145 of the container 140 to be filled. The container 140 is positioned under the filling element 100 by means of a container holding device 150, for example by means of a gripper element in the form of a neck handling clip. Fig. 1 also shows a cleaning-in-place (CIP) device 180, by means of which the filling element 100 can be cleaned.

Via the pressure gas channel 160 and the associated pressure gas valve 170, the container 140 is preloaded to a preload pressure before the filling process begins. The filling valve 110 of the filling element 100 is then opened by moving the valve stem 115. Due to the upward movement of the valve stem 115, the closure member 125 of the filling valve 110 is retracted from its valve seat 120, so that the liquid to be filled can pass through the closure member 125 via the filling channel 105 into the pressure sleeve 128 and the container 140. Since the opening of the valve seat 120 has a smaller cross-section than the passage in the pressure sleeve 128, the liquid enters the container 140 via the mouth 145 as a jet.

During filling, the pre-loading gas escapes from the side of the filling valve 110 through the pressurized gas channel 160 and through the pressurized gas valve 170. For example, carbon dioxide used as the pressure gas can be recovered in this manner and returned to the storage vessel. It is also known to feed pressurized gas back into a gas chamber above the product to be filled, for example, back into an annular bowl. In this way, the container can be filled at equal pressure. However, the pre-loaded gas may also escape elsewhere or remain partially in the vessel.

After the filling process is completed, in conventional filling systems, a pressure relief valve 165 depressurizes the headspace of the filled container under increased pressure. For this purpose, the pressure relief valve is opened after the filling valve 110 is closed, so that the pre-charge gas in the headspace can be reduced via the pre-charge channel 160 and the pressure relief valve 165. In a particular further development, which is shown in fig. 1, the decompression channel for decompressing the head space of the container before lifting the filling element 100 is partly identical to the preloading channel. However, because the reduced pressure occurs at ambient pressure, conventional filling systems provide a separate reduced pressure path through which the pre-load gas can escape from the headspace.

The depressurization path requires space inside the filler rotating equipment and must also be integrated into the cleaning circuit. For this purpose, separate rails have to be provided in the media distributor of the filling systems of the prior art, which increases the installation costs as well as the maintenance costs. The connection is made from the media distributor via several distribution lines leading into the annular channel. The filling valves are connected separately from the annular channel. In order to be able to depressurize each filling element individually, each filling element must be equipped with its own depressurization valve.

During periods of time when regular cleaning is required, conventional filling systems do not ensure that sufficient cleaning and sterilising medium is carried in each relief passage. For example, a pressure relief valve that is unable to open or close due to increased temperature or that is blocked is often not easily detectable. For example, metering monitoring can only be ensured by temperature and flow rate monitoring of each filling element, but is very laborious and therefore cannot be carried out from an economic point of view. This also leads to increased space requirements.

In the case of further hygiene measures, the use of filling valves with pressure-reducing channels is only conceivable for filling systems for weakly acidic beverages. In addition to monitoring the temperature and flow rate of the individual pressure-relief ducts for producing still beverages, a thermal shut-off of the pressure-relief ducts from the environment must also be provided, for example in the form of a vapour barrier. In general, providing a separate pressure relief passage for the filling element increases the installation and cleaning costs and maintenance costs of the entire filling system.

The present invention is therefore based on the object of providing a method for filling containers with a liquid under increased pressure, and a filling system for a counter-pressure filling machine for carrying out the method, which avoids the above-mentioned disadvantages. In particular, the headspace of the filled container should be depressurized without high installation and maintenance costs. Furthermore, the cleaning of the filling system should be simplified. In summary, the invention is based on the object of providing a method and a filling system for filling carbonated beverages, which can be used, in particular, under high hygiene standards and which are not expensive to maintain.

Disclosure of Invention

The above mentioned object is solved by a method for filling a container with a liquid under increased pressure, comprising the steps of: establishing a substantially airtight contact between the container opening and the outlet opening, in particular by pressing the container opening of the container to be filled against the outlet opening of the filling element; preloading the container to be filled with a preloading gas by means of a gas connection of the filling element until a preloading pressure is reached; filling the container with the liquid by means of the filling valve of the filling element; and separating the container opening from the outlet opening after completion of the filling process, in particular withdrawing the container opening from the outlet opening; wherein the contact between the container opening and the outlet opening is temporarily released at least once to at least partially reduce the preload pressure before the container opening is separated or withdrawn.

For example, the container may be a bottle or a tank. Increased pressure means here and in the following a pressure above ambient pressure. The liquid may in particular be a liquid food product, such as a drink. The emulsion or suspension can also be filled under increased pressure. Finally, liquid products that are not food products (such as cosmetics, cleaning products or similar products) can also be filled into the container under pressure.

As already mentioned, the container opening (e.g. the mouthpiece) is first pressed against the outlet opening of the filling element, thus establishing a substantially airtight contact. As already described, this pressure can be applied by lifting the container and/or lowering the filling element. The filling element may be part of a large number of filling elements arranged along the circumference of a filling line designed as a rotary machine. The outlet opening of the filling element is correspondingly shaped and arranged to ensure a substantially airtight contact. Substantially gas-tight contact is to be understood here and hereinafter as a mechanical contact which impedes the escape of gas even at the prevailing filling pressure during the filling process. The outlet opening of the filling element can be provided on a separately provided pressure sleeve, for example as shown in fig. 1, whereby the pressure sleeve can be replaced as a format part when changing to another container type.

In order to prevent the carbonated beverage from generating unnecessary foaming during filling, the container to be filled is preloaded with a preloading gas to a preloading pressure above ambient pressure before the filling process starts. The pre-loading gas is supplied under pressure into the container, for example via a pre-loading gas channel as shown in fig. 1, until the desired pre-loading pressure is reached. The filling element is supplied via a gas connection. As mentioned above, the pre-load gas is preferably or comprises an inert gas, such as carbon dioxide. The preload pressure can be selected in dependence on the filling pressure. In particular, counter-pressure filling can be performed at a constant pressure given by the preload pressure. In this case, the preloading gas is continuously fed back from the container via the pressure gas channel during filling and stored in a gas chamber, for example, above the liquid source. In a particular further development, the container and the pressure gas channel and the reservoir (e.g. an annular reservoir) form a pressure-balanced communication system for the product to be filled.

By opening the filling valve of the filling element, the container is then filled with the liquid, whereby the device can be set up to ensure that the desired filling quantity is filled. A large number of such devices are known in the art and are therefore not described in detail here. For example, a probe may be inserted into the container as a filling level sensor that signals that a desired filling level has been reached. A gas return tube can also be provided, in particular connected to the pressure gas channel, which gas return tube is inserted into the container and determines the maximum filling level by its lower end. Alternatively, as mentioned above, the filling can be performed according to the jet principle, i.e. in particular without an air return tube. Depending on the flow sensor or the filling quantity metering, the desired filling quantity can be ensured. Correction of the filling quantity can also be provided by controlled refilling as part of the filling process.

After the filling process is completed, in particular after the head space above the filling liquid in the container is depressurized, the container opening is separated from the outlet opening, for example by suction, so that the filled container can finally be removed for further processing. Depending on the process used for pressing the filling element, the filling element is withdrawn by lowering the container and/or lifting the filling element or the filling valve.

According to the invention, the gastight contact between the container opening and the outlet opening is temporarily released at least once before the last separation of the container opening, in order to at least partly reduce the preload pressure. In other words, the container and/or the filling element or parts of the filling element are moved at least once, so that the container opening and the outlet opening are temporarily separated from one another by a gap or clearance to such an extent that: so that a part of the gas present in the headspace of the container under increased pressure, in particular the pre-loaded gas, can escape through the created gap or slit. This portion of gas in the headspace (i.e. in the volume of the container within the container above the filling level) escapes directly to the environment.

At least for the first time, the contact is only temporarily released and then reestablished, so that the foam generated by the liquid in the container as a result of the spontaneous decompression can settle again before the contact is released again or finally. In particular, the contact can be temporarily released and re-established several times before the container opening is finally separated from the outlet opening. This allows the headspace to be gradually or completely depressurized to a pressure close to ambient pressure, so that only slight foaming of the filled product occurs during the final separation.

Since the gas in the head space escapes directly into the environment through the resulting gap, further pressure reduction by means of a separately provided pressure reduction valve is definitely not necessary according to the invention. In particular, such a pressure relief valve can be dispensed with altogether, which greatly reduces the installation effort and simplifies the required routine cleaning.

According to a further development, the contact can be released by a relative movement of the filling element and/or the container. The relative movement occurs in particular along the longitudinal axis of the container or the filling element. For example, the filling element can be lifted pneumatically from the container opening. For this purpose, compressed air can be selectively introduced into the chambers provided for this purpose by means of closed-loop and/or open-loop units of the filling machine in order to cause a displacement of the filling element. Alternatively, the filling element can be lifted mechanically, for example by means of a servomotor or a control cam.

According to a further refinement, the contact can be released by temporarily lifting the filling element from the container opening, whereby the movement of the filling element during the lifting is limited by the mechanical block. According to this further development, the container is not lowered to release the contact, but the filling element is lifted. For example, by means of a suitable receiving and/or holding device, the container may be held immovable along the longitudinal axis of the container, while suitable means are provided to allow displacement of the filling element along the longitudinal axis. For example, by blowing compressed air into a chamber provided for this purpose, the filling element can be lifted along the longitudinal axis until a suitably designed element of the filling element (e.g. a locking element) mechanically engages with the mechanical block. The mechanical block limits the relative movement of the filling element and thus the width of the annular gap formed at the container opening when the contact is lifted. In this way, the rate at which the pressure in the headspace is reduced can be effectively limited.

In particular, the contact can be temporarily released repeatedly before the container opening is finally separated from the outlet opening or lifted off. The pressure in the headspace of the container is further reduced whenever contact is temporarily released. Repeated lifting contacts can prevent the carbonated product being filled from foaming out.

The pre-loaded gas may particularly be or comprise carbon dioxide and the liquid may particularly be a carbonated beverage. For example, the carbonated beverage may be beer, sparkling wine, soft drinks, and the like. Carbon dioxide is used as a pre-load gas to displace oxygen and other contaminant gases in the container to be filled and to maintain the carbon dioxide content of the filled beverage during the filling process. The use of carbon dioxide or any other inert gas, such as nitrogen, as the pre-loading gas or part thereof also increases the shelf life of the filled product.

As already mentioned, the pre-loading gas can be partially recovered during the filling process via a gas connection. For this purpose, during the filling process, a suitable pressure gas valve can be opened so that a portion of the preloading gas can flow back from the container, for example back to the storage container, via the pressure gas valve. In this way, the need for pre-loading gas can be reduced.

The described method can also be used for filling containers with weakly acidic beverages. Weakly acidic beverages, such as milk or vegetable milk substitutes, generally require higher hygiene standards than carbonated beverages. The described method can also be used for filling such weakly acidic beverages, since the pressure relief channel of conventional filling machines, which are difficult to clean, is no longer required.

The above-mentioned object is also solved by a filling system of a counter-pressure filling machine for carrying out one of the above-mentioned methods, whereby the filling system comprises: at least one filling element having an outlet opening which can be pressed substantially gas-tight against a container opening of a container to be filled, the filling element having a gas connection for pre-loading gas and a filling valve for liquid; and at least one receiving and/or holding device for the containers to be filled; wherein the filling element and/or the receiving and/or holding device are configured to be movable relative to each other along an axis, in particular along a longitudinal axis of the container, such that the outlet opening of the filling element and the container opening are accessible for filling; wherein a lifting device is provided which is configured to temporarily release the contact between the outlet opening and the container opening by moving the filling element and/or the receiving and/or holding device along the axis.

The same variants and further improvements described above in connection with the method for filling containers according to the invention can also be applied here to the filling system. For example, the outlet opening can be formed in a suitably shaped pressure sleeve of the filling element. Alternatively, the outlet opening of the filling valve itself can be in airtight contact with the container opening. For this purpose, the outlet openings are suitably shaped and arranged to ensure the required airtightness of the contact with the respective container openings under the filling pressure.

The gas connection for the preloading gas can have a pressure gas valve which can be opened in a controlled manner to preload the container. The gas connection can be connected to a pressure gas channel, which can be connected, for example, to a storage container for pressure gas or to a gas chamber above the filling product in a storage container for the liquid to be filled. The receiving and/or holding device for the container to be filled can be designed such that the container can be lifted up to be pressed against the outlet opening. Alternatively, the receiving and/or holding device can be fixed in the axial direction, the filling element being lowered accordingly to establish contact between the outlet opening and the container opening. For example, the receiving and/or holding device may have a gripper element, in particular for the neck manipulation of plastic bottles.

In particular, the lifting device may be designed such that it can move the filling element and/or the receiving and/or holding device along the axis in a controlled manner. For example, the lifting device may act pneumatically on the filling element and/or the receiving and/or holding device, whereby suitable pressure chambers, supply lines, discharge lines, valves, pumps, etc. may be provided to achieve a relative displacement of the filling element and the receiving and/or holding device. Alternatively, mechanical means (such as control cams, operating levers and/or electric motors) may be provided which cause a relative displacement, for example as a function of the angular position of the filling element relative to a filling machine designed as a rotary unit.

According to a further refinement, the filling element is relatively movable along the axis, whereby the lifting device is designed to lift the filling element from the container opening to release the contact. According to this further development, the receiving and/or holding device for the containers to be filled can be formed immovable, in particular with respect to the axial movement.

As a result of the axial displacement of the entire filling element, a larger cross-sectional area is available for this further development, on which the gas pressure of the pneumatically operated lifting device can act, for example, in the pressure chamber. This means that the filling element can also be lifted from the container opening against a filling pressure which presses the filling valve against the container opening. According to a particular further development, the filling valve itself can be pressed against the container opening instead of the aforementioned pressure sleeve. With the filling element, the filling valve is also temporarily lifted from the container opening.

As already mentioned, the filling valve can be designed as a so-called jet valve, whereby in particular the valve seat of the filling valve can be offset backwards from the outlet opening. An axial distance thus exists between the outlet opening and the valve seat of the filling valve, so that the product to be filled enters the container in the form of a jet when the filling valve is open. Here and in the following, filling using the jet principle means that the cross section of the filling jet is smaller than the cross section of the container opening, so that pre-loading gas displaced by the filled product can escape from the container opening beyond the filling jet.

The gas connection of the filling element may have a pressure gas valve which is arranged at the level of the valve seat when viewed in the axial direction. Arranged at the height of the valve seat means that the pressure gas valve is arranged within an axial distance of less than 2cm from the valve seat. Furthermore, the radial distance of the pressure gas valve, i.e. the distance perpendicular to the above-mentioned axis, may be less than 2 cm. The described arrangement of the pressure gas valve minimizes dead space (dead space) on the filling element, thus avoiding unwanted contamination.

The filling element may be equipped with mechanical blocks, in particular switchable blocks, to limit the movement of the filling element during lifting. For example, a cam may be provided to limit the lifting of the filling element along the axis. Since only a small stroke is required for depressurizing the head space by temporarily lifting the filling element from the container opening, the mechanical block can be opened after the filling element has been lowered into the container opening and closed after the filling process has been completed, so that the filling element can finally be lifted out of the container opening. For example, the mechanical block can be switched via cam control.

The filling system may also comprise at least one connection for compressed air, the filling element being designed such that it can be pneumatically lifted from the container opening via the compressed air connection. The compressed air may be ambient air or a suitable gas such as nitrogen. The filling system may have more than one adjustable valve that can be opened and closed by a closed-loop and/or open-loop unit of the filling line to supply or discharge compressed air. The respective supply and discharge lines for compressed air may be provided as generally known. Due to the large cross-section of the filling element, a small amount of compressed air pressure is sufficient to pneumatically lift the filling element.

In accordance with one of the above-mentioned further developments, the invention also provides a counter-pressure filling machine with a plurality of filling systems, which further comprises a closed-loop and/or open-loop unit, which is designed to repeatedly release the contact between the outlet opening and the container opening before the depressurization to ambient pressure takes place. The depressurization to ambient pressure can be achieved in particular by finally separating the outlet opening and the container opening. As described above, repeated release of contact may cause depressurization of the headspace without foaming of the liquid being filled. For example, the closed-loop and/or open-loop unit can be designed as a programmable logic controller which determines the number and frequency of the relative movements of the filling element and the container depending on the filling product, the filling pressure and/or the container type.

The described filling system can be designed specifically without a separate pressure relief channel or without a pressure relief valve, so that on the one hand the installation effort is reduced and on the other hand a complicated cleaning system can be dispensed with. This makes the described counter-pressure filling machine also suitable for filling containers with weakly acidic beverages.

Further features and exemplary embodiments and advantages of the invention are explained in more detail below using the figures. The examples are of course not exhaustive of the scope of the invention. It goes without saying that some or all of the features described below can be combined in other ways.

Drawings

Fig. 1 schematically shows a conventional filling element with a separate pressure relief valve.

Fig. 2 schematically shows a filling element according to the invention.

Fig. 3 to 7 show a sequence of the method for filling containers according to the invention.

Detailed Description

In the drawings described below, like reference numerals refer to like elements. For clarity, identical elements are described only when they first appear. However, it goes without saying that the variants and embodiments of the elements described with reference to one of the figures can also be applied to corresponding elements in other figures.

Fig. 2 schematically shows a filling element 200 according to the invention. Like the conventional filling element shown in fig. 1, the filling element according to the invention also has a filling valve 210, the filling valve 210 having a closure part 225, the closure part 225 being retractable from its valve seat 220 as indicated by the double arrow by means of a valve stem 215. However, the invention is not limited to further modifications of the filling valve described above, but can be used with other known filling valves. However, unlike conventional filling elements, the filling element shown in fig. 2 does not have a separate pressure sleeve. Instead, the filling valve 210 with its outlet opening 230 is lowered directly to the container opening 145 of the container 140 to be filled.

In the non-limiting further development shown here, the opening of the filling valve 220 is itself surrounded by an annular opening through which the pre-loading gas can be introduced into the container 140 via the pressure gas channel 260. In contrast, the gas present in the container at the beginning of the filling process escapes via this opening and the pressure gas channel 260 during the filling of the container with the filling product. The filling product is filled like a jet into the container 140 through the valve seat 220 via the filling channel 205. However, it is to be understood that the invention is not limited to the above further modifications and in particular, a pressure sleeve may be provided between the filling valve 210 and the mouth of the container 140.

As is known, the pressure gas channel 260 is equipped with a valve 270, which valve 270 can be opened and closed in a controlled manner, so that the introduction of the pre-loaded gas into the container and the escape of the gas from the container can be controlled. In particular, the pressure prevailing in the container during the filling process can be regulated by means of the valve 270. The valve 270 can be controlled by a closed-loop and/or open-loop unit 285 of the filling system. For example, the closed-loop and/or open-loop unit 285 may be a programmable logic controller having a processor and at least one storage medium. However, in contrast to conventional filling elements, the filling element shown in fig. 2 does not have a pressure relief valve that can be used to depressurize the headspace of the filled container prior to removal of the container.

Instead, the illustrated filling element has a lifting device 290, by means of which the entire filling element 200 can be moved pneumatically along the longitudinal axis of the filling element or container. In the further development shown here, the lifting device 290 is arranged above the holding device 252 for the filling element 200, the holding device 252 being in particular vertically fixed, whereby the lifting device 290 is firmly connected to the holding device 252 while the filling element 200 can be moved vertically within the lifting device 290. For the pneumatic movement of the filling elements, the lifting device 290 comprises

supply lines

291 and 293 for compressed air, the

supply lines

291 and 293 being connected to respective

annular chambers

292 and 294. Not shown, but as is well known, suitable controllable valves, a source of compressed air and/or one or more pumps may be provided to apply compressed air to the

supply lines

291 and 293. The

supply lines

291 and 293 can simultaneously serve as discharge lines. The control of the valves or compressed air source via

supply lines

291 and 293 can also be taken over by the closed and/or open loop unit 285. The connection of the pressurized gas channel 260 to the filling element is designed such that a vertical movement of the filling element can be ensured. For this purpose, appropriately designed sealing elements can be used, and/or a part of the pressure gas channel can be designed flexibly.

According to a further embodiment described above, the surface of the substantially cylindrical shaped filling element 200 has an annular protrusion 295, the annular protrusion 295 being in the form of an annular shoulder, rail or the like, vertically movable in the cylindrical chamber of the lifting device 290. In the non-limiting further development shown here, two projections 295 are provided, a sealing ring 296 being arranged between the two projections 295, the sealing ring 296 separating the upper pressure chamber 292 from the lower pressure chamber 294 in a gastight manner.

By introducing compressed air into the annular pressure chamber 292 via the supply line 291, a downward force is generated on the protrusion 295 and thus on the filling element 200, which downward force moves the filling element downward as indicated by the double arrow and places it with the outlet opening 230 on the mouth 145 of the container 140 to be filled. Conversely, by introducing compressed air into the annular pressure chamber 294 via the supply line 293, an upward force can be generated on the lower projection 295, which causes the filling element 200 to be displaced upward along its longitudinal axis. In particular, by the controlled introduction of compressed air into pressure chamber 294 as described above, filling element 200 can be temporarily lifted from container opening 145, so that an annular gap is formed between container opening 145 and outlet opening 230 of the filling element.

Through this annular gap, a part of the gas in the headspace of the container can escape, thus partially reducing the gas pressure in the headspace. By releasing the compressed air in the lower pressure chamber 294 and simultaneously introducing the compressed air into the upper pressure chamber 292, the contact between the filling element and the container opening 145 can be reestablished, so that the liquid in the container can settle down again. This process can be repeated whereby the height of the lifting motion and the duration of contact release can be used to determine to what extent the gas pressure in the headspace is reduced.

According to the further illustrated embodiment, since the entire filling element 200, rather than only the filling valve 210, is moved along the longitudinal axis, a larger cross section Q as indicated by the dashed line in fig. 2 can be used for the pneumatic control of the lifting movement. In this way, even the low pressure in the pressure chamber 294 is sufficient to lift the filling element 200 vertically upwards against the filling pressure.

It is to be understood, however, that the invention is not limited to the above-described further development with pneumatic lifting devices, but may also be implemented with mechanical lifting devices, for example with mechanical levers, control cams and/or one or more servomotors.

By pneumatically lifting the filling element 200 from the container opening 145, the pre-loading gas can escape directly into the environment via the resulting annular gap. In particular, the pressure relief path and the pressure relief valve provided by conventional filling elements can be dispensed with. This also eliminates the need for additional dispensing tracks in the media dispenser, and the need for the necessary valves for opening and closing the various reduced pressure paths during cleaning and sterilization of the filling system.

The further development shown in fig. 2 also comprises a bellows 255 which is arranged at the lower end of the filling element 200 and can be lowered together with the filling element through the container opening 145. Bellows 255 prevents contaminants from entering the area between filling valve 210 and container opening 145.

In the further development shown, a pressure gas valve 270 is arranged on one side of the pressure gas channel 260. However, as mentioned above, the gas valve may be specifically located at the height of the valve seat 220, e.g., immediately adjacent to the valve seat. In this way, dead space in the pressure gas channel 260 can be reduced to a minimum.

Fig. 3 to 7 show a sequence of processes for filling containers according to the invention. For a better understanding, the drawings are limited to the elements necessary for an understanding.

Fig. 3 shows the filling element according to the invention in the basic position before the filling process begins. In the non-limiting further development shown here, the filling element has a pressure sleeve 228 with which an airtight contact between the outlet opening and the container opening of the container 140 is established. In the basic position, the filling element is separated from the container opening. In the further development shown, the container 140 is positioned below the filling element by a receiving and/or holding device designed as a gripper device 250. The gripper device 250 is attached to the valve carrier plate 252, the valve carrier plate 252 carrying, in addition to the shown filling elements, many other filling elements, for example as part of a filling machine designed as a rotary unit.

Fig. 3 furthermore schematically shows a pressurized gas channel 260, the previously described bellows 255 and the filling valve 210 with its schematically illustrated valve seat 220. In the basic position, the black illustration of the filling valve shows the closing element closing off the valve seat 220. In this basic position, too, the pressure gas channel 26 is closed by a pressure gas valve, not shown.

At the beginning of the filling process, as shown in fig. 4, the filling element is first lowered in the direction of the arrow to the container opening, so that an airtight contact is formed between the pressure sleeve 228 and the container opening. Filling valve 210 first remains closed after contact has been established. However, the pressure gas channel 260 is correspondingly opened by actuating the pressure gas valve, so that the preloading gas is introduced under pressure into the container 140 and preloads the container 140 to the preloading pressure.

When the preload pressure is reached, as indicated by the arrow in fig. 5, filling valve 210 is opened by moving the closure member vertically so that product enters container 140 through the opening in valve seat 220 and pressure sleeve 228. At the same time, the pre-loading gas in the container can escape via the pressure gas channel 260 and be circulated. During the entire filling process, the outlet opening of the filling element remains in gas-tight mechanical contact with the container opening, as indicated by the arrow. The filling process continues until the desired filling level is reached in the container as indicated in fig. 5. The volume above the fill level is commonly referred to as headspace 142. When the desired filling level is reached, filling valve 210 is closed as indicated by the arrow in fig. 6 by moving the closure member against valve seat 220. The pressure gas channel 260 is also closed by means of a pressure gas valve.

During counter-pressure filling, the gas present in the headspace 142 after the actual filling process is completed (in particular the pre-loading gas) is under increased pressure. Unlike the conventional method, the method according to the invention shown in fig. 6 reduces this increased pressure, but by temporarily lifting the filling element from the container opening. This can be done, for example, as described above, by pneumatically lifting the filling element for a limited lift, as indicated by the arrow in the drawing. This lifting thus opens an annular gap between the pressure sleeve 228 and the container opening through which gas can partially escape from the headspace 142. In this way, the gas pressure in the headspace is partially reduced.

As described above, the filling element is lowered again to the container opening after it has been lifted for a short time, so that an airtight contact between the pressure sleeve 228 and the container opening is established again. This allows the frothed carbonated beverage to settle again during the depressurization process before repeating the process or the contact is finally released. The depressurization may be performed once or repeatedly as described above before the final release of contact.

Finally, as indicated by the arrow in fig. 7, the filling element is completely lifted and thus separated from the filled container. The filled containers can then be removed by suitable equipment, for example, from the gripper apparatus 250 to an exit starwheel or downstream container handler, such as a capper. The filling element then returns to its initial position.

The described filling element and filling method do not require a separately provided decompression path, which greatly reduces installation and cleaning efforts. Because the reduced pressure path is eliminated, there is also no significant process uncertainty resulting from the lack of monitoring the cleaning and sterilization of the previously conventional reduced pressure path. The filling element according to the invention can thus also be used for filling weakly acidic products, which increases the microbiological requirements for hygiene. The described method can be used for carbonated and non-carbonated beverages as well as for non-food products.

Claims

1. A method of filling a container (140) with a liquid under increased pressure, comprising:

establishing a substantially gas-tight contact between a container opening (145) of a container (140) to be filled and an outlet opening (230) of a filling element (200);

preloading the container (140) to be filled with a preloading gas by means of a gas connection (260) of the filling element until a preloading pressure is reached;

-filling said container (140) with a liquid by means of a filling valve (210) of said filling element; and

separating the container opening (145) from the outlet opening (230) after completion of the filling process;

it is characterized in that the preparation method is characterized in that,

prior to separating the container opening, contact between the container opening (145) and the outlet opening (230) is temporarily released at least once to at least partially reduce the preload pressure.

2. Method according to claim 1, wherein the contact is released by a relative movement of the filling element (200) and/or the container (140).

3. Method according to claim 2, wherein the filling element (200) is pneumatically lifted from the container opening (145).

4. Method according to one of the preceding claims, wherein the contact is released by temporarily lifting the filling element (200) from the container opening (145), and wherein the movement of the filling element (200) during lifting is limited by a mechanical block.

5. Method according to one of the preceding claims, wherein the contact is temporarily released repeatedly before separating the container opening (145) from the outlet opening (230).

6. Method according to one of the preceding claims, wherein the pre-loading gas is or comprises carbon dioxide and wherein the liquid is in particular a carbonated beverage.

7. Method according to one of the preceding claims, wherein the pre-loading gas is partly recovered via the gas connection (260) during the filling process.

8. A method according to any preceding claim, wherein the liquid is a weakly acidic beverage.

9. Filling system of a counter-pressure filling machine for implementing a method according to one of the preceding claims, comprising:

at least one filling element (200) having an outlet opening (230), the outlet opening (230) being able to be pressed substantially gas-tightly against a container opening (145) of a container (140) to be filled, the filling element (200) having a gas connection (260) for pre-loaded gas and a filling valve (210) for liquid; and

at least one receiving and/or holding device (250) for the containers to be filled;

wherein the filling element (200) and/or the receiving and/or holding device (250) are configured to be movable relative to each other along an axis, in particular a longitudinal axis of the container, such that the outlet opening (230) of the filling element and the container opening (145) are contactable for filling;

it is characterized in that the preparation method is characterized in that,

a lifting device (290) configured to temporarily release the contact between the outlet opening (230) and the container opening (145) by moving the filling element (200) and/or the receiving and/or holding device along the axis.

10. The filling system according to claim 9, wherein the filling element (200) is relatively movable along the axis, the lifting device (290) being adapted to lift the filling element from the container opening (145) to release the contact.

11. The filling system according to claim 10, wherein the filling valve (210) is designed as a jet valve, in particular with its valve seat (220) offset from the outlet opening (230).

12. The filling system of claim 11, wherein the gas connection (260) comprises a pressure gas valve (270) arranged at the level of the valve seat (220) with respect to the axis.

13. The filling system according to one of claims 10 to 12, wherein the filling element (200) has a mechanical block, in particular an openable mechanical block, for limiting the movement of the filling element during lifting.

14. The filling system according to one of claims 10 to 13, further comprising at least one connection (291, 293) for compressed air, wherein the filling element (200) is designed such that it can be pneumatically lifted from the container opening (145) via a compressed air connection.

15. Counter-pressure filling machine comprising a plurality of filling systems according to one of claims 9 to 14, further comprising a closed-loop and/or open-loop control unit (285) adapted to repeatedly release contact between the outlet opening (230) and the container opening (145) before a depressurization to ambient pressure occurs.