EP3650402B1 - Method for counterpressure filling of containers and filling system of a counterpressure filling device - Google Patents

Description

field of invention

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

State of the art

When filling liquids under pressure into containers, for example when filling carbonated products and beverages into bottles or cans, the mouths of the containers to be filled are pressed essentially gas-tight during the filling process against an outlet of the filling element used, so that the filling product enters the container under increased pressure Container can be introduced.

The container to be filled can be lifted by means of a suitable movement device and pressed against the filling element, ie the outlet of the filling element used, as is the case, for example, in the German Offenlegungsschrift DE 41 34 446 A1 is described. Alternatively, the filling element can be lowered onto the mouth of the container until a gas-tight contact is made, as for example in the German Offenlegungsschrift DE 41 01 891 A1 is described. By means of suitably designed sealing means and centering means, it can be ensured that the outlet opening is placed in the exact position on the mouth of the container to be filled and is kept essentially gas-tight during the filling process.

In the DE 27 22 274 B1 discloses a device for relieving the head pressure in the liquid-free container head during counter-pressure filling, in which a ring-shaped vent gap is produced by means of a lifting device, through which the gas in the head space to be vented escapes in a controllable manner.

Before filling, the container can be pre-flushed with a rinsing gas, for example nitrogen or carbon dioxide, particularly in the case of oxygen-sensitive products. By filling in the liquid under increased pressure, the pressure in the container also increases continuously. Alternatively or additionally, the containers can be prestressed to a prestressing pressure via a stressing gas channel with a stressing gas, in particular with carbon dioxide the container is then filled with the product, in particular a carbonated product, under constant pressure.

After the container is filled with the liquid or product, the pressurized headspace of the container is vented through a relief path and associated relief valve relieved. In this case, the relief generally takes place at the ambient pressure. After the relief, the filling element is pulled off the mouth of the container or the container is lowered so that the filled container can be removed from the filling machine, for example a filler carousel.

A filling system of a counter-pressure filler, as is known in the prior art, is for example in figure 1 shown. The filling element 100 is arranged in a height-adjustable manner on a holding device 152 . In the position shown in the figure, the filling element 100 has already been lowered with the outlet opening 130 of a pressure sleeve 128 onto the mouth 145 of the container 140 to be filled. The container 140 is positioned below the filling element 100 by means of a container holding device 150, for example by means of a gripping element in the form of a neck handling clamp. the figure 1 FIG. 12 also shows a Cleaning-In-Place (CIP) device 180, by means of which the filling element 100 can be cleaned.

The container 140 is prestressed to the prestressing pressure via a prestressing gas channel 160 and an associated prestressing gas valve 170 before the start of the filling process. Then the filling valve 110 of the filling element 100 is opened by moving the valve rod 115 . Due to the upward movement of the valve rod 115, the closure part 125 of the filling valve 110 is pulled back from its valve seat 120, so that the liquid to be filled in can enter the pressure sleeve 128 and the container 140 through the filling channel 105 past the closure part 125. Since the opening of the valve seat 120 has a smaller cross section than the channel present in the pressure sleeve 128, the liquid enters the container 140 through the opening 145 as a free jet.

During filling, the prestressing gas escapes laterally past the filling valve 110 through the prestressing gas channel 160 and via the prestressing gas valve 170. For example, carbon dioxide used as prestressing gas can be recovered in this way and returned to a storage container. It is also known to return the pressurized gas to a gas space above the product to be filled, for example to a ring bowl. In this way, the container can be filled under constant pressure. However, the biasing gas can also escape in other ways or partially remain in the container.

After completion of the filling process, in the usual filling systems, the headspace of the filled container, which is under increased pressure, is relieved by means of the relief valve 165 . For this purpose, the relief valve is opened after the filling valve 110 has been closed, so that the preload gas located in the head space can expand via the preload channel 160 and the relief valve 165 . In the in the figure 1 illustrated special training is the relief channel for relieving the headspace of the container before lifting the filling element 100 is partially identical to the preload channel. However, since the relief takes place at ambient pressure, separate relief paths are provided in the usual filling systems, via which the preload gas can escape from the headspace.

The relief paths require space inside the filler carousel and must also be integrated into the cleaning circuit. For this purpose, in the filling systems of the prior art, a separate track must be provided in the media distributor, which increases the installation and maintenance costs. The connection is made from the media distributor via several distribution lines that end in a ring channel. The filling valves are connected individually from this ring channel. In order to be able to grant an individual relief for each filling element, each filling element must be equipped with its own relief valve.

During the cleaning that is required at regular intervals, it is not ensured with the usual filling systems that sufficient cleaning and sterilization medium is fed through every relief channel. Relief valves that do not switch or jam due to an increased temperature, for example, cannot generally be detected without further ado. Metrological monitoring can only be guaranteed with great effort, for example by monitoring the temperature and flow of each filling element, and is therefore not feasible from an economic point of view. Likewise, there would be an increased space requirement.

The use of a filling valve with a relief channel for a filling system for weakly acidic beverages is only conceivable with the use of further hygienic measures. In addition to monitoring the temperature and flow rate of the individual relief ducts for the production of still drinks, a thermal barrier between the relief duct and the environment, for example in the form of a vapor barrier, would have to be provided. Overall, the provision of separate relief channels for the filling elements increases both the installation and the cleaning and maintenance costs of the entire bottling plant.

It is therefore the object of the present invention to provide a method for filling containers with a liquid under increased pressure and a filling system of a counter-pressure filler for carrying out the method, which avoid the disadvantages described above. In particular, a relief of the headspace of the filled container should be made possible without high installation and maintenance costs. In addition, the cleaning of the filling system should be simplified. In general, the present invention is the The object is to provide a method and a filling system for bottling, in particular, carbonated beverages that can be used with high hygienic standards and without high maintenance costs.

Description of the invention

The above-mentioned objects are achieved by a method for filling containers with a liquid under increased pressure, with the steps: creating a substantially gas-tight contact between a container opening of a container to be filled and an outlet opening of a filling element, in particular by pressing the container opening the outlet port; Preloading the container to be filled with a preload gas until a preload pressure is reached by means of a gas connection of the filling element; filling the container with the liquid by means of a filling valve of the filling element; and separating, in particular pulling off, the container opening from the outlet opening after completion of the filling process; wherein the contact between the container opening and the outlet opening is temporarily broken at least once before the container opening is separated or pulled off, in order to bring about an at least partial relief of the preload pressure.

The containers can be bottles or cans, for example. Here and in the following, an increased pressure is to be understood as meaning a pressure which is above the ambient pressure. The liquid can in particular be a liquid foodstuff, for example a drink. Likewise, emulsions or suspensions can also be filled in under increased pressure. Finally, liquid products that are not foodstuffs, for example cosmetic products, cleaning products or the like, can also be filled into the containers under pressure.

As already mentioned, the container opening, for example the mouth of a bottle, is first pressed against an outlet opening of a filling element, as a result of which an essentially gas-tight contact is produced. As already described, this pressing can take place by raising the container and/or lowering the filling element. The filling element can belong to a multiplicity of filling systems designed as a rotary machine along a circumference. The outlet opening of the filling element is shaped and arranged accordingly in order to be able to ensure a substantially gas-tight contact. A substantially gas-tight contact is to be understood here and in the following as a mechanical contact which blocks gas from escaping even under the filling pressure prevailing during the filling process. The outlet opening of the filling element can be attached to a pressure sleeve provided separately for this purpose, such as for example in the figure 1 shown, be provided, the pressure sleeve can be exchanged as a format part when changing to a different type of container.

In order to prevent undesired foaming of carbonated beverages during bottling, the container to be filled is preloaded with a preloading gas to a preloading pressure above ambient pressure before the start of the filling process. The bias gas, for example, on the in the figure 1 shown tensioning gas channel, introduced under pressure into the container until the desired pretensioning pressure is reached. The introduction takes place via a gas connection of the filling element. As mentioned above, the biasing gas is or preferably comprises an inert gas such as carbon dioxide. The preload pressure can be selected according to the filling pressure. In particular, the counter-pressure filling can take place with a constant pressure that is given by the preload pressure. In this case, the prestressing gas is successively fed back out of the container via the prestressing gas channel during filling and is stored, for example, in a gas space above a supply of liquid. In a special development, the container and the pressurized gas channel and store, for example a ring store, form a communicating system in pressure equilibrium for the product to be filled.

The container is then filled with the liquid by opening the filling valve of the filling element, it being possible for devices to be provided which ensure filling with a desired filling quantity. A variety of such devices are known in the prior art and will therefore not be described in detail here. For example, a probe can be inserted into the container as a filling level sensor, which reports that a desired filling level has been reached. A return gas pipe, in particular with a connection to the pressurized gas channel, can also be provided, which is inserted into the container and defines the maximum filling level through its lower end. Alternatively, as already described above, filling can take place according to the free jet principle, i.e. in particular without a return gas pipe. The desired filling quantity can be guaranteed by means of flow sensors or filling quantity portioning. In addition, as part of the filling process, a correction of the filling quantity can be provided by controlled refilling.

After completion of the filling process, and in particular after relieving the headspace above the filled liquid in the container, the container opening is separated from the outlet opening, for example by pulling it off, so that the filled container can finally be removed for further processing. According to the procedure when pressing on, the removal takes place by lowering the container and/or raising the filling element or filling valve.

According to the present invention, the gas-tight contact between the container opening and the outlet opening is temporarily broken at least once before the container opening is finally separated, in order to bring about an at least partial relief of the preload pressure. In other words, the container and/or the filling element or parts of the filling element are moved at least once in such a way that the container opening and outlet opening are temporarily separated from one another by a gap or a gap to such an extent that a part of the gas present in the head space of the container, which is under increased pressure, in particular pre-pressurizing gas, can escape. This part of the gas in the headspace, i.e. in the volume of the container above the filling level inside the container, escapes directly into the environment.

At least the first time, the contact is only temporarily broken and then restored again, so that a liquid in the container that is foaming due to the spontaneous pressure drop can calm down again before the contact is broken again or finally. In particular, the contact can be temporarily canceled and restored several times before the container opening is finally separated from the outlet opening. This allows the headspace to be successively vented to near ambient pressure or all the way to ambient pressure, resulting in little foaming of the filled product upon final separation.

Since the gas in the head space escapes directly into the environment through the resulting gap, according to the present invention there is explicitly no further relief by a relief valve provided separately for this purpose. In particular, such a relief valve can be completely dispensed with, as a result of which the installation effort is considerably reduced and the cleaning that is required on a regular basis can be simplified.

According to a further development, the contact can be eliminated by moving the filling element and/or the container relative to each other. The relative movement takes place in particular along a 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 chambers provided for this purpose by means of a control and/or regulating unit of the filling machine in order to cause a displacement of the filling element. Alternatively, the filling element can be raised mechanically, for example by means of a servo motor or a cam.

According to a further development, the contact can be canceled by temporarily lifting the filling element from the container opening, with the movement of the filling element being limited by a mechanical lock during lifting. According to this training is thus the container is not lowered to break contact, but the filling element is raised. For example, the container can be held immovably along the longitudinal axis of the container by a corresponding receiving and/or holding device, while suitable devices are provided to enable displacement of the filling element along the longitudinal axis. For example, the filling element can be raised along the longitudinal axis by blowing compressed air into a chamber provided for this purpose, until a correspondingly designed element, for example a locking element, of the filling element is brought into mechanical engagement with the mechanical lock. The mechanical lock limits the relative movement of the filling element and thus the width of the annular gap that forms at the container opening when the contact is removed. In this way, the rate at which headspace pressure is relieved can be effectively limited.

In particular, the contact can be temporarily canceled repeatedly before the container opening is finally separated or lifted from the outlet opening. Each momentary cessation of contact causes a further release of pressure in the headspace of the container. By repeatedly breaking the contact, foaming over of a charged carbonated product can be prevented.

The biasing gas can be or include carbon dioxide, in particular, with the liquid being in particular a carbonated beverage. For example, the carbonated drink can be beer, sparkling wine, soft drinks or the like. The use of carbon dioxide as a prepressurizing gas on the one hand displaces oxygen and other foreign gases from the container to be filled, on the other hand maintains the carbonic acid content of the beverage filled in during the filling process. The use of carbon dioxide or another inert gas, such as nitrogen, as or as part of a biasing gas also increases the shelf life of the filled product.

As already mentioned, the biasing gas can be partially recovered via the gas connection during the filling process. For this purpose, a corresponding pressurized gas valve can be opened during the filling process, so that part of the pressurized gas can flow back out of the container via the pressurized gas valve, for example into a reservoir. In this way, the need for bias gas can be reduced.

The methods described can also be used to fill containers with a weakly acidic beverage. Low-acid beverages, such as milk or plant-based milk alternatives, generally require higher hygiene standards than, for example, carbonated beverages. The methods described can also be used for filling such weakly acidic beverages can be used, as the difficult-to-clean discharge channels of conventional bottlers are no longer required.

The above-mentioned objects are also achieved by a filling system of a counter-pressure filler for carrying out one of the methods described above, the filling system comprising: at least one filling element with an outlet opening which can be pressed in a substantially gas-tight manner against a container opening of a container to be filled, the filling element having a Gas connection for the bias gas and a filling valve for the liquid; and at least one receiving and/or holding device for the container to be filled; wherein the filling element and/or the receiving and/or holding device are designed to be movable relative to one another along an axis, in particular a longitudinal axis of the container, such that the outlet opening of the filling element and the container opening can be brought into contact for filling; a lifting device being provided which is designed to temporarily eliminate 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.

Here, the same variations and developments that were described above in connection with the method according to the invention for filling containers can also be applied to the filling system. For example, the outlet opening can be formed in a correspondingly shaped pressure sleeve of the filling element. Alternatively, an outlet opening of the filling valve itself can be brought into gas-tight contact with the container opening. For this purpose, the outlet opening is shaped and arranged accordingly in order to ensure the required gas tightness under the filling pressure in contact with the respective container opening.

The gas connection for the preload gas can have a preload gas valve that can be opened in a controlled manner to preload the container. A tensioning gas channel can be connected to the gas connection, which can be connected, for example, to a reservoir for the tensioning gas or to a gas space above the filling product in a reservoir for the liquid to be filled. The receiving and/or holding device for the container to be filled can be designed in such a way that the container can be lifted to press against the outlet opening. Alternatively, the receiving and/or holding device can be designed to be fixed in the axial direction, with the filling element being correspondingly lowered in order to establish contact between the outlet opening and the container opening. The receiving and/or holding device can, for example, have a gripping element, in particular for neck handling of plastic bottles.

The lifting device can in particular be designed in such a way 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 can act pneumatically on the filling element and/or the receiving and/or holding device, with suitable pressure chambers, supply lines, discharge lines, valves, pumps and the like being provided in order to compensate for the relative displacement of the filling element and the receiving and/or holding device to effect. Alternatively, mechanical means, for example control curves, levers and/or motors, can be provided which bring about the relative displacement, for example depending on an angular position of the filling element with respect to a filling machine designed as a rotary machine.

According to a further development, the filling element can be designed to be relatively movable along the axis, with the lifting device being designed to lift the filling element from the container opening in order to break the contact. According to this development, the receiving and/or holding device for the container to be filled can be designed to be stationary, in particular with respect to an axial movement.

Due to the fact that the complete filling element is moved in the axial direction, a larger cross-sectional area is available in this further development, on which a gas pressure of a pneumatically operated lifting device can act, for example in a pressure chamber. As a result, the filling element can also be lifted off the container opening against the filling pressure that presses the filling valve onto it. According to a special development, the filling valve itself can be pressed against the container opening instead of the previously mentioned pressure sleeve. The filling valve is thus also temporarily lifted from the container opening with the filling element.

As already mentioned, the filling valve can be designed as a so-called free jet valve, in which case, in particular, a valve seat of the filling valve can be arranged set back from the outlet opening. Thus, there is an axial distance 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 free jet when the filling valve is open. Here and in the following, filling according to the free-jet principle means that the cross-section of the filling jet is smaller than the cross-section of the container opening, so that the prestressing gas displaced by the filled product can escape past the filling jet and out of the container opening.

The gas connection of the filling element can have a tension gas valve, which is arranged at the height of the valve seat when viewed in the direction of the axis. An arrangement at the level of the valve seat is to be understood here as meaning that the tensioning gas valve is within an axial distance less than 2 cm from the valve seat. In addition, the radial distance, ie the distance perpendicular to the axis referred to above, of the compressed gas valve can be less than 2 cm. The described arrangement of the tensioning gas valve reduces dead spaces on the filling element to a minimum, as a result of which undesirable contamination can be avoided.

The filling element can have a mechanical lock, in particular a switchable one, for limiting the movement of the filling element during death. For example, a cam can be provided which limits the lifting of the filling element along the axis. Since only a small stroke is required to relieve the headspace by temporarily lifting the filling element from the container opening, the mechanical lock can be switched on after the filling element has been lowered onto the container opening and switched off after the filling process has been completed, so that the filling element can finally be lifted off the container opening can. The switching of the mechanical lock can take place, for example, via a cam control.

The filling system can also include at least one connection for compressed air, the filling element being designed in such a way that it can be lifted pneumatically from the container opening via the compressed air connection. The compressed air can be ambient air or a suitable gas such as nitrogen. The filling system can have one or more controllable valves, which can be opened and closed by means of a control and/or regulating unit of the filling system in order to supply or discharge the compressed air. Appropriate inlet and outlet lines for the compressed air can be provided, as is generally known. Due to the larger cross section of the filling element, even a low compressed air pressure is sufficient to lift the filling element pneumatically.

The present invention also provides a counter-pressure filler with a multiplicity of filling systems according to one of the developments described above, which further comprises a control and/or regulating unit which is designed to repeatedly cancel the contact between the outlet opening and the container opening before relief occurs ambient pressure takes place. In this case, the relief to ambient pressure can take place in particular by finally separating the outlet opening and the container opening. As described above, by repeatedly breaking the contact, a gradual relief of the head space can be effected without foaming over of the filled liquid. The control and/or regulation unit can be designed, for example, as a programmable logic controller that determines the number and frequency of the relative movements of the filling element and container as a function of the filling product, the filling pressure and/or the type of container.

The filling systems described can be designed explicitly without a separate relief channel or without a relief valve, so that on the one hand the installation effort is reduced and on the other hand complex cleaning systems can be dispensed with. The counter-pressure filler described is therefore also suitable for filling containers with weakly acidic beverages.

Figur 1

zeigt schematisch ein herkömmliches Füllelement mit separatem Entlastungsventil.

Figur 2

zeigt schematisch ein Füllelement gemäß der vorliegenden Erfindung.

Further features and exemplary embodiments as well as advantages of the present invention are explained in more detail below with reference to the drawings. It is understood that the embodiments do not exhaust the scope of the present invention. It is also understood that some or all of the features described below can also be combined with one another in other ways.

figure 1

shows schematically a conventional filling element with a separate relief valve.

figure 2

shows schematically a filling element according to the present invention.

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

In the figures described below, the same reference symbols designate the same elements. For the sake of clarity, the same elements are only described when they first appear. However, it goes without saying that the variants and embodiments of an element described with reference to one of the figures can also be applied to the corresponding elements in the other figures.

In the figure 2 a filling element 200 according to the present invention is shown schematically. Like the one in the figure 1 illustrated conventional filling element also has the filling element according to the invention a filling valve 210 with a closure part 225 which can be withdrawn from its valve seat 220 by means of a valve rod 215 as indicated by the double arrow. However, the present invention is not limited to the illustrated development of the filling valve and can use other known filling valves. Unlike the conventional filling element, the one in the figure 2 Filling element shown, however, no separate pressure sleeve is provided. Instead, the filling valve 210 is lowered with its outlet opening 230 directly onto the container opening 145 of the container 140 to be filled.

In the non-limiting development shown here, the opening of the filling valve 220 itself is surrounded by an annular opening through which preload gas can be introduced into the container 140 via the preload gas channel 260 . Conversely, the gas present in the container at the beginning of the filling process escapes via this opening and the compressed gas channel 260 during filling of the container with the filling product. The filling product is filled into the container 140 as a free jet via a filling channel 205 past the valve seat 220 . However, it goes without saying that the present invention is not limited to the illustrated development, and in particular a pressure sleeve can be provided between the filling valve 210 and the mouth of the container 140 .

As is known per se, the biasing gas channel 260 is equipped with a valve 270 which can be opened and closed in a controlled manner so that the introduction of biasing gas into the container and the escape of gas from the container can be controlled. In particular, the pressure prevailing in the container during the filling process can be adjusted by means of the valve 270 . The control of the valve 270 can be taken over by a control and/or regulation unit 285 of the filling system. The control and/or regulation unit 285 can be, for example, a programmable logic controller with a processor and at least one storage medium. Unlike the conventional filling elements, the one in the figure 2 However, no relief valve is provided for the filling element shown, via which the headspace of the filled container could be relieved before the container is removed.

Instead, the filling element shown has a lifting device 290, by means of which the entire filling element 200 can be moved pneumatically along a longitudinal axis of the filling element or of the container. In the development shown here, lifting device 290 is provided above a holding device 252, which is in particular vertically fixed, for filling element 200, lifting device 290 being fixedly connected to holding device 252, while filling element 200 can move vertically within lifting device 290. In order to move the filling element pneumatically, the lifting device 290 comprises supply lines 291 and 293 for compressed air, which are connected to corresponding annular chambers 292 and 294. Not shown, but as known per se, corresponding controllable valves, a compressed air supply and/or one or more pumps can be provided in order to pressurize the supply lines 291 and 293 with compressed air in a targeted manner. The supply lines 291 and 293 can serve as discharge lines at the same time. The control of the valves or the compressed air supply via the supply lines 291 and 293 can also be taken over by the control and/or regulating unit 285 . The connection of the tensioning gas channel 260 to the filling element is designed in such a way that the vertical mobility of the filling element is ensured. Appropriately designed sealing elements can be used for this purpose and/or part of the pressurized gas channel can be designed to be flexible.

According to the illustrated development, the surface of the generally cylindrical filling element 200 has ring-shaped projections 295 in the form of a ring-shaped shoulder, bar or the like, which can move vertically in a cylindrical cavity of the lifting device 290 . In the non-limiting development shown here, two extensions 295 are provided, between which a sealing ring 296 is arranged, which separates the upper pressure chamber 292 from the lower pressure chamber 294 in a gas-tight manner.

By introducing compressed air via the supply line 291 into the annular pressure chamber 292, a downward force is generated on the extension 295 and thus the filling element 200, which pushes the filling element downwards, as indicated by the double arrow, and with the outlet opening 230 onto the orifice 145 of the container to be filled 140 touches down. Conversely, by introducing compressed air via the supply line 293 into the annular pressure chamber 294, an upward-acting force can be generated on the lower extension 295, which causes the filling element 200 to be displaced upwards along its longitudinal axis. In particular, the filling element 200 can be temporarily lifted from the container opening 145 as described above by the controlled introduction of compressed air into the pressure chamber 294, as a result of which an annular gap forms between the container opening 145 and the outlet opening 230 of the filling element.

Part of the gas in the head space of the container can escape through this annular gap, which causes a partial relief of the gas pressure in the head space. By expanding the compressed air in the lower pressure chamber 294 and simultaneously introducing compressed air into the upper pressure chamber 292, the contact between the filling element and the container opening 145 can be restored, so that the liquid in the container can calm down again. This process can be carried out repeatedly, it being possible to determine how far the gas pressure in the headspace is relieved via the height of the lifting movement and the duration of the elimination of the contact.

Since, according to the illustrated development, the entire filling element 200, and not just the filling valve 210, is moved along the longitudinal axis, a larger cross section Q is available for the pneumatic control of the lifting movement, as is shown in FIG figure 2 is indicated by the dashed line. In this way, even a low pressure in the pressure chamber 294 is sufficient to lift the filling element 200 vertically upwards against the filling pressure.

However, it goes without saying that the present invention is not limited to the illustrated development with a pneumatic lifting device, but can also be implemented using mechanical lifting devices, for example using a mechanical lever, a cam and/or one or more servomotors.

By pneumatically lifting the filling element 200 from the container opening 145, the prestressing gas can escape directly into the environment via the annular gap that is produced. In particular, the relief paths and relief valves provided with conventional filling elements can be dispensed with. This also eliminates the need for an additional distributor track in the media distributor and the necessary valves for switching the respective relief path on and off when cleaning and sterilizing the filling system.

The one in the figure 2 The development shown also has a bellows 255 which is provided at the lower end of the filling element 200 and can be lowered over the container opening 145 with the filling element. The bellows 255 prevent dirt from entering the area between the filling valve 210 and the container opening 145.

In the development shown, the tensioning gas valve 270 is provided on the side of the tensioning gas channel 260 . However, as described above, the compressed gas valve can be arranged in particular at the height of the valve seat 220, for example in the immediate vicinity of the valve seat. In this way, dead spaces in the clamping gas channel 260 can be reduced to a minimum.

the Figures 3 to 7 show the sequence of a method for filling containers according to the present invention. In this case, the figures are limited to the elements that are essential for understanding, in order to make them easier to understand.

In the figure 3 the filling element according to the present invention is shown in the basic position before the start of the filling process. In the non-limiting development shown here, the filling element has a pressing sleeve 228 with which the gas-tight 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 development shown, the container 140 is positioned under the filling element by a receiving and/or holding device designed as a gripping device 250 . The gripping device 250 is fastened to a valve carrier plate 252 which, in addition to the filling element shown, carries a large number of other filling elements, for example as part of a filling machine designed as a rotary machine.

Furthermore, the figure 3 schematically shows the tensioning gas channel 260, the bellows 255 described above and the filling valve 210 with its valve seat 220, shown schematically. In the basic position, the closure part of the filling valve shown in black closes the valve seat 220. In this basic position, the tensioning gas channel 260 is also closed by a tensioning gas valve, not shown.

At the beginning of the filling process, as in figure 4 shown, the filling element is first lowered onto the container opening in the direction of the arrow, so that a gas-tight contact is formed between the pressure sleeve 228 and the container opening. The filling valve 210 initially remains closed after making contact. On the other hand, the inflating gas channel 260 is opened by appropriate activation of the inflating gas valve, so that the preloading gas is introduced under pressure into the container 140 and preloads it to the preloading pressure.

Once the preload pressure has been reached, the filling valve 210 is opened by moving the closure part vertically, as indicated by the arrow in FIG figure 5 opened indicated, so that the product enters the container 140 through the opening in the valve seat 220 and the pressure sleeve 228 . At the same time, the biasing gas in the container can escape via the biasing gas channel 260 and be recycled. 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 as shown in the figure 5 indicated a desired level is reached in the container. The volume above this fill level is commonly referred to as headspace 142 . If the desired level is reached, the filling valve 210 as indicated by the arrow in FIG figure 6 indicated closed by the closure part is driven against the valve seat 220. Likewise, the pressurized gas channel 260 is also closed by means of the pressurized gas valve.

During counter-pressure filling, the gas, in particular the preload gas, which is present in the head space 142 after the actual filling process has been completed, is under increased pressure. In contrast to the conventional methods, this increased pressure is relieved according to the method according to the invention as in FIG figure 6 shown, however, by temporarily lifting the filling element from the container opening. This can be done, for example, as described above, by lifting the filling element pneumatically, as indicated by the arrow in the figure, by a limited stroke. The lifting thus opens an annular gap between the pressure sleeve 228 and the container opening, through which the gas can partially escape from the head space 142 . In this way, a partial relief of the gas pressure in the head space thus takes place.

As described above, the filling element is lowered again onto the container opening after it has been lifted for a short time, so that a gas-tight contact between the pressure sleeve 228 and the container opening is created again. This allows a carbonated beverage foaming during the discharge to settle before repeating the process or finally breaking contact. The depressurization can be carried out once or repeatedly, as described above, before the contact is finally broken.

Finally, the fill element as indicated by the arrow in the figure 7 indicated completely raised and thus separated from the filled container. This can then be removed by suitable devices and, for example, transferred from the gripping device 250 to an outlet starwheel or a downstream container treatment machine, for example a capper. The filling element is then back in the basic position.

The filling elements and filling methods described do not require separately provided relief paths, which means that the installation and cleaning effort can be significantly reduced. Since there are no discharge paths, there is also no considerable process uncertainty, which arises from the lack of monitoring of the cleaning and sterilization of the discharge paths that have been customary up to now. Thus, the filling elements according to the invention can also be used for filling weakly acidic products that place increased microbiological demands on hygiene. The methods described can be used for both carbonated and non-carbonated beverages, as well as for non-food products.

Claims (15)

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

   establish 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);

   pre-tensioning, by means of a gas connection (260) of the filling element, the container (140) to be filled with a preload gas until a preload pressure is reached;

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

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

   characterized in that

   the contact between the container opening (145) and the outlet opening (230) is temporarily cancelled at least once prior to separation of the container opening and subsequently restored to effect at least partial relief of the preload pressure.
2. The method according to claim 1, wherein the contact is cancelled by relatively moving the filling element (200) and/or the container (140).
3. The method according to claim 2, wherein the filling element (200) is pneumatically lifted from the container opening (145).
4. The method according to any one of the preceding claims, wherein the contact is cancelled by temporarily lifting the filling element (200) from the container opening (145), and wherein the movement of the filling element (200) during the lifting is limited by a mechanical lock.
5. The method according to any one of the preceding claims, wherein the contact is repeatedly temporarily cancelled and subsequently restored before the container opening (145) is separated from the outlet opening (230).
6. The method according to any one of the preceding claims, wherein the preload gas is or comprises carbon dioxide, and wherein the liquid is in particular a carbonated beverage.
7. The method according to any one of the preceding claims, wherein the preload gas is partially recovered via the gas port (260) during the filling process.
8. The method according to any one of the preceding claims, wherein the liquid is a weakly acidic beverage.
9. A filling system of a counter-pressure filling device for carrying out the method according to any one of the preceding claims, comprising:

   at least one filling element (200) having an outlet opening (230) pressable against a container opening (145) of a container (140) to be filled in a substantially gas-tight manner,

   wherein the filling element (200) comprises a gas connection (260) for the preload gas and a filling valve (210) for the liquid; and

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

   wherein the filling element (200) and/or the receiving and/or holding device (250) are configured to be movable relative to one another along an axis, in particular a longitudinal axis of the container, in such a way that the outlet opening (230) of the filling element and the container opening (145) can be brought into contact for filling;

   characterized by

   a lifting device (290) which is configured to temporarily cancel 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 (250) along the axis and then restoring it.
10. The filling system according to claim 9, wherein the filling element (200) is configured to be relatively movable along the axis and the lifting device (290) is configured to lift the filling element from the container opening (145) to cancel the contact.
11. The filling system according to claim 10, wherein the filling valve (210) is designed as a free-flow valve, and in particular a valve seat (220) of the filling valve is set back from the outlet opening (230).
12. The filling system according to claim 11, wherein the gas connection (260) comprises a clamping gas valve (270) arranged at the level of the valve seat (220) with respect to the axis.
13. The filling system according to any one of claims 10 to 12, wherein the filling element (200) comprises a, in particular switchable, mechanical lock for limiting the movement of the filling element during lifting.
14. The filling system according to any one of claims 10 to 13, further comprising at least one connection (291, 293) for compressed air, wherein the filling element (200) is configured such that it can be pneumatically lifted from the container opening (145) via the compressed air connection.
15. A counter-pressure filling device having a plurality of filling systems according to any one of claims 9 to 14, further comprising a control and/or regulating unit (285) adapted to repeatedly cancel the contact between the outlet opening (230) and the container opening (145) and then restore contact before relief to ambient pressure.

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