EP3345863B1 - Filling system and method for filling cans - Google Patents

Description

The invention relates to a filling device of the type defined in the preamble of claim 1 and a method for filling cans.

Filling devices and methods for filling containers are known in many different embodiments. In order to always fill the same filling quantity into the container, in the prior art for filling the container with a desired filling volume, the filling quantity is determined via the filling level, which is set by the position of the opening of a return air pipe or a return air bore of the filling device or by means of a sensor (level probe ) and actuator (valve) and suitable control logic - usually electronically or electro-pneumatically.

Known filling systems, which use a probe designed as a small tube with a return air duct, which is arranged to reach into the container, to control the fill level during filling, provide that during the filling process the out of the container on which the filling device is arranged in a sealed manner, through gas displaced by the inflowing fluid is discharged from the container via the return air duct. The filling process is automatically terminated when the end of the channel protruding into the container is immersed in the fluid level. To correct the fill level, the container is then subjected to a gas with a slight excess pressure, so that excess fluid is pushed back through the return air duct into the storage container and the fluid level has dropped to the level of the probe opening.

Before the actual filling process, air is usually removed from the container - to avoid undesirable gas binding, gas exchange or gas entry with atmospheric oxygen, which can result in a change in quality of the fluid due to oxidation reactions or increased germ contamination - both when filling the tank without pressure and when filling it under pressure containers arranged in a sealed position on the filling device are evacuated and/or flushed with a sterile gas or inert gas, which can be filled in via the return air duct. This channel can also be used to apply the counter pressure intended for filling to the container.

A disadvantage of such filling systems are the fluid residues from a previous filling process that remain in the connecting paths between the return air duct and the reservoir and are blown into the container as an aerosol together with the gas during pressure equalization or covering. When filling a carbonated fluid, this can lead to CO2 escaping from the fluid and thus to excessive foam development at the end of the filling process.

To avoid this, revealed DE 10 2008 030 948 A1 discloses such a filling system with a probe which determines the level, one end of the channel extending into the respective container during filling and having a return air channel which is open at the end of the channel. In order to enable dry pressure equalization or dry pre-stressing of the containers during pressure filling, the flow path for pressure equalization or pre-stressing is largely separated from the flow path for returning excess filling material when correcting the filling level using several valves in this filling system.

Also US 3,830,265A and JP H04 31293 A disclose filling devices for pressure-filling cylindrical containers: The filling devices each have a filling valve which is guided in a sealed manner in a sealing head which is designed to be placed on the container opening in a sealing manner. The inflation valve is fully inserted into the container to expel most of the gas contained in the container before or after the sealing head is placed in sealing relation to the container opening, the container being vented and pressurized with pressurized gas before the inflation valve is opened and the filling product is introduced into the Container is transferred. During filling, the compressed gas contained in the container is returned to a filling tank via return air pipes and valves in order to keep the pressure in the container constant during filling.

Another way of controlling the filling quantity in the containers is offered by the control logic using a flow meter (usually magnetically inductive or using the Coriolis force). With this control logic, the tank volume is unimportant as the amount of liquid is measured during the filling process. The disadvantage of this filling method is its price-performance ratio and the fact that expensive sensors, actuators and controls have to be used because the control electronics (PLC) have to be very fast and precise at the same time.

Proceeding from this state of the art, it is the object of this invention to provide a device that is simpler in terms of apparatus without a return air line, i. H. without a return air duct with its large number of valves, for filling (essentially) cylindrical containers such as cans, which enables pressure equalization or prestressing and filling without complex measuring and control technology and does not require a filling level correction.

This object is achieved by a filling arrangement with the features of claim 1.

The further object of being able to fill cylindrical containers without a return air line and without measuring equipment using a simply constructed apparatus without filling level correction is achieved by the method with the features of independent claim 5 .

Preferred embodiments are set out in the subclaims.

The filling arrangement according to the invention consists of a filling device and a predetermined cylindrical container, which is a can, the container opening of which has a diameter which is smaller than the inner diameter of the predetermined container by a predetermined amount. The filling device has a filling valve with a piston that is controllably guided in a filling tube. ("Predetermined dimension" means the known ratio resulting from the diameters, which are defined here by the predetermined dimensions of the respectively known and therefore predetermined (selected) container.) The opening direction of the filling valve is arbitrary. It is important that the filling valve has the largest possible outer diameter and is designed to match the diameter of the container opening, so that the filling valve can be inserted coaxially into the container through the container opening, preferably without friction. The portion of the fill valve intended for insertion into the container has a volume in the range of 33 to 99% of the container volume. The portion of the inflation valve predetermined for insertion refers to that portion of the inflation valve which is inserted into the container when the inflation valve has reached the bottom end position. The filling valve thus has an outside diameter that is slightly smaller than the diameter of the container opening, with the tolerances due to the precise manufacturability of the cylindrical container, in particular cans, can be small. However, the invention provides that when imported Filling valve an annular gap is left between the filling valve and the container opening to allow the escape of air or gas when inserting the filling valve into the container. This annular gap preferably has a width in the millimeter range and can be, for example, 1 to 5% for commercially available beverage cans. To insert the filling valve into the container, the filling valve can be moved relative to the container, ie the filling valve is either designed to be movable or the container is moved in relation to the filling valve by means of a movable container receptacle.

The filling device is particularly suitable for cylindrical containers such as cans, the container openings of which have a diameter which is 70 to 99.5% of the container inner diameter, so that the portion of the filling valve intended for insertion into the container, the outer diameter of which is adapted to the opening diameter, has a volume in the range of 49 to 99% of the container volume. In principle, however, a filling device according to the invention can also be provided for containers whose container opening diameter is less than 70% of the container inner diameter, as long as the geometric dimensions and thus the volume of the predetermined container are exactly known or can be determined, as in the case of cans.

The filling device has an attachment tube which is arranged coaxially around the filling valve for sealing placement on the container opening. Furthermore, the attachment tube can be moved in a controlled manner relative to the filling valve, the filling valve being slidingly mounted in the attachment tube in a sealing manner. The attachment tube is designed for fluid communication or for gas exchange with the interior of the container, i.e. at the point at which the attachment tube touches the container opening, there is also an annular gap, now between the filling valve and the attachment tube, to allow the exchange of air or to permit gas with the interior of the container upon movement of the inflation valve in and out of the container when the top tube is placed in sealing relation on the container. For the sealed sliding bearing in the attachment tube, the invention provides that the filling valve has a collar whose diameter is adapted to the inner diameter of the attachment tube. A sliding seal is arranged peripherally on the collar to permit relative movement between the filling valve and the attachment tube and at the same time to seal the space in the attachment tube around the filling valve upwardly on the side remote from the container.

With this simply constructed filling device, the filling, in particular the pressure filling, of a cylindrical container such as a can without a return air line and without complex measurement and control technology is made possible by means of a method according to the invention, which is based on a sub-layer filling process in which the filling valve is only opened when it is fully inserted into the container and then opened and moved upwards in the container, with the fluid level in the container, which occurs when the pressure in the container is equalized between the filling pressure and the back pressure, is always above the filling valve opening. Inflation Valve Orifice means the opening end of the inflation valve or the opened sealing seat of the inflation valve. The method of the present invention is described in detail below.

However, the invention also includes embodiments of filling valves that open in the opposite direction, i. H. that the piston is moved downwards with respect to the filling tube.

For sealing placement on the container opening, the attachment tube can preferably have an annular shoulder, which is designed with a sealing seat adapted to the container opening. The sealing seat can be equipped with a conventional sealing element.

Both the sealing seat and the sliding seal of the attachment tube are designed to be gas-tight, so that gas trapped within the container and the attachment tube cannot escape.

Preferably, the collar is spaced a certain distance from the inflation valve opening. The (minimum) distance of the collar from the filling valve opening can depend on the height of the predetermined container that is to be filled with the filling device if the collar on the filling tube is to come into contact with the ring shoulder of the attachment tube when the section of the filling valve intended for insertion is fully received within the container, ie the fill valve opening is at the container bottom or a predetermined defined distance provided for full insertion above the container bottom. However, the distance between the collar and the filling valve opening can also be greater than the distance specified by the height of the container: the collar then comes to lie clearly above the annular shoulder when the section of the filling valve intended for insertion is completely accommodated in the container.

The upward movement of the filling valve during filling releases volume in the attachment tube which is occupied by the gas which is displaced from the container during filling with the fluid. As a result of this volume compensation, the gas volume enclosed within the container and the attachment tube, which is placed in a sealed position, and thus also the pressure, remain constant. The extension tube is dimensioned in such a way that the released volume always corresponds to the displaced volume. For this purpose, the attachment tube can have an inner diameter which essentially corresponds to the inner diameter of the predetermined container.

The filling valve will usually also have a circular cross-section corresponding to the usual circular cross-sectional shapes of containers such as cans. If the shape of the container to be filled and the container opening deviate from the circular shape, the outer contours of the filling valve and the attachment tube are adapted to it.

A further embodiment of the filling device according to the invention ensures a further improvement in the filling process in that the inclusion of gas bubbles, which would lead to undesired foaming at the end of the filling process, is minimized by a directed flow. For this purpose, the filling valve has a flow guide structure on an inside of the filling tube or on an outside of the piston or on both above the respective sealing surfaces, which is designed to set the fluid exiting the filling valve into a swirling or eddying movement. The rotating flow of the fluid prevents the fluid from hitting the lateral container wall radially and rebounding there, which would trap gas bubbles that could accumulate during the upward movement of the filling valve and lead to increased foaming. The rotating flow creates significantly fewer gas bubbles, which are also smaller and are close to the surface of the rising fluid level, so they collapse before filling is complete, preventing increased foaming.

The flow guide structure can be formed, for example, by one or more helical webs similar to a thread or by blading.

The blading can be formed by a ring of guide vanes which are curved at least in one plane, ie in the circumferential direction in relation to the radial plane. The However, guide vanes can also be curved in two planes, ie in the circumferential direction and in the longitudinal direction in relation to the radial plane.

Alternatively, if the piston of the filling valve is designed to be rotatable, the blading can be formed by a ring of rotating blades, which can be curved or uncurved, and are arranged on the rotatable piston. In the case of curved rotor blades, no drive is advantageously required, since the fluid flowing past causes the piston to rotate. With non-curved blades, the piston is driven to rotate.

1. a) Das geschlossene Füllventil wird in Bezug zu dem Behälter koaxial mit der Behälteröffnung auf einer vorbestimmten ersten Höhe positioniert, die durch den im Behälter einzustellenden Gegendruck in Abhängigkeit der gegebenen geometrischen Abmessungen des Behälters und des Füllventils sowie des herrschenden Ausgangsdrucks bestimmt wird. Dabei kann das geschlossene Füllventil durch die Behälteröffnung in den Behälter eingeführt werden, wenn die vorbestimmte erste Höhe zwischen der Behälteröffnung und dem Boden des Behälters liegt, wobei in dem Behälter zuvor vorhandenes Gas entsprechend dem Volumen des eingeführten Teilabschnitts des Füllventils aus dem Behälter in die Umgebung verdrängt wird.
2. b) Mit dem Füllventil auf der ersten vorbestimmten Höhe wird das Aufsatzrohr abdichtend auf die Behälteröffnung aufgesetzt, wobei eine vorbestimmbare Gasmenge innerhalb des Behälters und des Aufsatzrohrs verbleibt, die sich aus einem Teilvolumen im Behälter und einem Teilvolumen in dem um das Füllventil abgedichteten Aufsatzrohr zusammensetzt, das durch den Kragen mit der Gleitdichtung um das Füllventil abgedichtet ist.
3. c) Mit dem vollständigen Einführen des Füllventils bei abdichtend aufgesetztem Aufsatzrohr wird die vorbestimmbare Gasmenge in einem Ringspalt, der in dem Behälter und in dem Aufsatzrohr um das vollständig eingeführte Füllventil vorliegt, auf den vorbestimmten Gegendruck komprimiert. Der erreichbare Gegendruck hängt bei einer gegebenen Behälter-Aufsatzrohr-Füllvorrichtung-Kombination und gegebenem Ausgangsdruck folglich nur von der ersten vorbestimmten Höhe ab, in der das Füllventil beim Abdichten mit dem Aufsatzrohr positioniert wird. Mit den gegebenen Abmessungen von Füllventil, Behälter und Aufsatzrohr beträgt das Gasvolumen die Differenz zwischen dem Behältervolumen plus Aufsatzrohrvolumen unterhalb des Kragens und dem Volumen des Füllventils.
4. d) Ist das Füllventil vollständig eingeführt, wodurch der vorbestimmte Gegendruck im Behälter erzeugt ist, wird das Füllventil geöffnet, sodass das Fluid mit einem vorbestimmten Fülldruck in den Ringspalt einströmt. Der Gegendruck ist in Bezug zum vorgesehenen Fülldruck derart gewählt, dass sich bei Druckausgleich zwischen dem Gegendruck und dem Fülldruck ein Fluidspiegel innerhalb des Ringspalts einstellt, der oberhalb der Füllventilöffnung im Ringspalt liegt.
5. e) Das geöffnete Füllventil wird dabei innerhalb des Behälters und innerhalb des Aufsatzrohrs aufwärts bewegt, wobei die Geschwindigkeit der Aufwärtsbewegung derart angepasst ist, dass der Fluidspiegel innerhalb des Ringspalts immer oberhalb der Füllventilöffnung bleibt, sodass ein unterschichtiger Befüllvorgang von unten nach oben erzielt wird, der sehr schnell durchgeführt werden kann und sich durch geringe Verwirbelungen und Turbulenzen und damit verringertes Aufschäumen bei kohlesäurehaltigen Fluiden auszeichnet. Hierdurch und durch die minimierte Grenzfläche des Fluidspiegels im Ringspalt kann zudem vorteilhaft eine Verringerung der möglichen Sauerstoffaufnahme erreicht werden, wenn das vorhandene Gas Luft ist. Mit der Füllvorrichtung wird ferner mit der Aufwärtsbewegung des Füllventils ein Gasteilvolumen in dem um das Füllventil mit dem Kragen durch die Gleitdichtung abgedichteten Aufsatzrohr freigegeben, das einem in den Behälter einströmenden Fluidvolumen entspricht, sodass eine Summe des Gasteilvolumens im Aufsatzrohr und eines Gasteilvolumens oberhalb des Fluidspiegels im Behälter dem Gasvolumen in Schritt c) entspricht. Durch dieses Ausgleichsvolumen im Aufsatzrohr kann auf eine Rückluftleitung mit den damit verbundenen Ventilen und auf Messmittel zur Regelung des Füllvorgangs verzichtet werden, da mit dem konstant bleibenden Gasvolumen vorteilhaft auch der vorbestimmte Gegendruck konstant bleibt.
6. f) Die Aufwärtsbewegung des geöffneten Füllventils wird bei Erreichen einer zweiten vorbestimmten Höhe beendet, wobei das vorbestimmte Füllvolumen in dem Behälter erreicht ist. Sobald die Bewegung des Füllventils beendet ist, steigt der Fluidspiegel aufgrund des herrschenden Druckausgleichs zwischen Gegendruck und Fülldruck auch bei geöffnetem Füllventil nicht mehr an. Die zweite Höhe, bei der die Aufwärtsbewegung des Füllventils beendet wird, wird im Voraus bestimmt basierend auf den bekannten Parametern der exakten und bekannten geometrischen Abmessungen von Behälter und Füllvorrichtung sowie dem definierten Abstand des Fluidspiegels oberhalb der Füllventilöffnung, der von den vorbestimmten Druckbedingungen abhängig und damit ebenfalls im Voraus bestimmbar ist. Nach Erreichen der vorbestimmten zweiten Höhe wird das Füllventil geschlossen. Eine Korrektur der Füllmenge ist nicht erforderlich.
7. g) Zum Verhindern des übermäßigen Aufschäumens durch plötzliche Druckentlastung beim Entfernen der Füllvorrichtung wird zunächst das Aufsatzrohr in Dichtlage auf dem Behälter belassen und nur das geschlossene Füllventil aus dem Behälter entfernt. Durch die Aufwärtsbewegung des geschlossenen Füllventils innerhalb des aufgesetzten Aufsatzrohrs kann gesteuert Volumen im Behälter und im Aufsatzrohr freigegeben werden und so der Gegendruck in angepasster Geschwindigkeit auf einen vorbestimmten Entlastungsdruck gesenkt und damit das Aufschäumen minimiert werden. h) Im letzten Schritt wird das Aufsatzrohr von der Behälteröffnung entfernt, sodass dieser den vorgesehenen nachfolgenden Prozessschritten zugeführt werden kann. Mit der Füllvorrichtung kann dann ein nächster Behälter durch Durchführung der Schritte des erfindungsgemäßen Verfahrens befüllt werden.

A method according to the invention for filling a predetermined cylindrical container with a fluid can be carried out without a return air line and without measuring equipment using a filling arrangement according to the invention. The procedure includes the following steps:

1. a) The closed filling valve is positioned coaxially with the container opening at a predetermined first height in relation to the container, which is determined by the back pressure to be set in the container depending on the given geometric dimensions of the container and the filling valve and the prevailing outlet pressure. The closed filling valve can be inserted into the container through the container opening when the predetermined first height is between the container opening and the bottom of the container, with gas previously present in the container corresponding to the volume of the inserted section of the filling valve being released from the container into the environment is displaced.
2. b) With the filling valve at the first predetermined height, the attachment tube is placed sealingly on the container opening, with a predeterminable amount of gas remaining inside the container and the attachment tube, which is composed of a partial volume in the container and a partial volume in the attachment tube sealed around the filling valve, which is sealed by the collar with the sliding seal around the inflation valve.
3. c) With the complete insertion of the filling valve with the attachment tube in place in a sealing manner, the predetermined quantity of gas is compressed to the predetermined back pressure in an annular gap which is present in the container and in the attachment tube around the completely inserted filling valve. The back pressure that can be achieved with a given combination of container, attachment tube and filling device and a given outlet pressure consequently depends only on the first predetermined height at which the filling valve is positioned when sealing with the attachment tube. With the given dimensions of filling valve, container and top tube, the gas volume is the difference between the container volume plus the top tube volume below the collar and the volume of the filling valve.
4. d) If the filling valve is fully inserted, as a result of which the predetermined back pressure is generated in the container, the filling valve is opened so that the fluid flows into the annular gap at a predetermined filling pressure. The back pressure is selected in relation to the intended filling pressure in such a way that when the pressure equalizes between the back pressure and the filling pressure, a fluid level is set within the annular gap which is above the filling valve opening in the annular gap.
5. e) The opened filling valve is moved upwards inside the container and inside the attachment tube, with the speed of the upward movement being adjusted in such a way that the fluid level within the annular gap always remains above the filling valve opening, so that a bottom-up filling process is achieved, the can be carried out very quickly and is characterized by low eddies and turbulence and thus reduced foaming in the case of fluids containing carbonic acid. As a result of this and the minimized boundary surface of the fluid level in the annular gap, a reduction in the possible oxygen uptake can also advantageously be achieved when the gas present is air. With the filling device, the upward movement of the filling valve also releases a partial gas volume in the attachment pipe sealed around the filling valve with the collar by the sliding seal, which corresponds to a fluid volume flowing into the container, so that a sum of the partial gas volume in the attachment pipe and a partial gas volume above the fluid level in the Container corresponds to the gas volume in step c). This compensating volume in the attachment tube makes it possible to dispense with a return air line with the associated valves and measuring means for controlling the filling process, since the predetermined back pressure advantageously also remains constant with the gas volume remaining constant.
6. f) The upward movement of the opened filling valve is terminated when a second predetermined height is reached, the predetermined filling volume in the container being reached. As soon as the movement of the filling valve has ended, the fluid level no longer rises, even when the filling valve is open, due to the prevailing pressure equalization between back pressure and filling pressure. The second height at which the upward movement of the filling valve is terminated is determined in advance based on the known parameters of the exact and known geometric dimensions of the container and filling device and the defined distance of the fluid level above the filling valve opening, which depends on the predetermined pressure conditions and therefore can also be determined in advance. After reaching the predetermined second height, the filling valve is closed. A correction of the filling quantity is not necessary.
7. g) To prevent excessive foaming caused by sudden depressurization when removing the filling device, first leave the attachment tube in the sealing position on the container and only remove the closed filling valve from the container. The upward movement of the closed filling valve within the attached attachment tube allows the volume in the container and in the attachment tube to be released in a controlled manner and the back pressure is reduced to a predetermined relief pressure at an appropriate speed, thus minimizing foaming. h) In the last step, the attachment tube is removed from the container opening so that it can be fed to the intended subsequent process steps. A next container can then be filled with the filling device by carrying out the steps of the method according to the invention.

The movements of the filling valve and the attachment tube described here in relation to the container are to be understood as relative movements: the description mainly assumes a stationary container, while the filling valve and the attachment tube can be moved relative to it and to one another, since this is the preferred embodiment represents. However, it is also possible that z. B. the filling valve is fixed, and the container (by means of a corresponding container receptacle) and the attachment tube can be moved. The third possible combination, that the attachment tube is fixed and the filling valve and container are movable, is also theoretically conceivable, but not preferred.

Other embodiments, as well as some of the advantages associated with these and other embodiments, will become apparent and better understood from the following detailed description with reference to the accompanying figures. Items or parts thereof that are substantially the same or similar may be given the same reference numbers. The figures are only a schematic representation of an embodiment of the invention.

Fig. 1

eine schematische Längsschnittansicht einer erfindungsgemäßen Füllvorrichtung mit einem zu befüllenden Behälter,

Fig. 2

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts a), p = p₀,

Fig. 3

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts b), p = p₀,

Fig. 4

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts c), p = p_G,

Fig. 5

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts d), p = p_G= p_F

Fig. 6

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts e), p = p_G= p_F und ΔV₁+ ΔV₂ = ΔV und p_G. ΔV = const.

Fig. 7

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts f), p = p_G = p_F und ΔV₁+ ΔV₂ = ΔV und p_G. ΔV = const.

Fig. 8

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung noch während des Verfahrensschritts f), p = p_G,

Fig. 9

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts g), p = p_E,

Fig. 10

eine schematische Längsschnittansicht der erfindungsgemäßen Füllvorrichtung während des Verfahrensschritts h), p = p₀,

Fig. 11

eine schematische Längsschnittansicht einer erfindungsgemäßen Füllvorrichtung mit einer wendelstegartigen Strömungsleitstruktur im Füllrohr,

Fig. 12

eine schematische Längsschnittansicht einer erfindungsgemäßen Füllvorrichtung mit einer wendelstegartigen Strömungsleitstruktur am Kolben,

Fig. 13

eine schematische Querschnittansicht einer erfindungsgemäßen Füllvorrichtung mit einer Strömungsleitstruktur aus Leitschaufeln am Kolben,

Fig. 14

eine schematische Querschnittansicht einer erfindungsgemäßen Füllvorrichtung mit einer Strömungsleitstruktur aus Laufschaufeln am rotierenden Kolben.

show:

1

a schematic longitudinal sectional view of a filling device according to the invention with a container to be filled,

2

a schematic longitudinal sectional view of the filling device according to the invention during the method step a), p = p ₀ ,

3

a schematic longitudinal sectional view of the filling device according to the invention during process step b), p = p ₀ ,

4

a schematic longitudinal sectional view of the filling device according to the invention during process step c), p = p _G ,

figure 5

a schematic longitudinal sectional view of the filling device according to the invention during process step d), p = p _G = p _F

6

a schematic longitudinal sectional view of the filling device according to the invention during the method step e), p = p _G = p _F and ΔV ₁ + ΔV ₂ = ΔV and p _G. ΔV = const.

7

a schematic longitudinal sectional view of the filling device according to the invention during the method step f), p = p _G = p _F and ΔV ₁ + ΔV ₂ = ΔV and p _G. ΔV = const.

8

a schematic longitudinal sectional view of the filling device according to the invention during method step f), p = p _G ,

9

a schematic longitudinal sectional view of the filling device according to the invention during process step g), p = p _E ,

10

a schematic longitudinal sectional view of the filling device according to the invention during the method step h), p = p ₀ ,

11

a schematic longitudinal sectional view of a filling device according to the invention with a helical web-like flow guide structure in the filling tube,

12

a schematic longitudinal sectional view of a filling device according to the invention with a helical web-like flow guide structure on the piston,

13

a schematic cross-sectional view of a filling device according to the invention with a flow guide structure made of guide vanes on the piston,

14

a schematic cross-sectional view of a filling device according to the invention with a flow guide structure of rotor blades on the rotating piston.

The filling device according to the invention is a device with a simple structure in terms of apparatus, which has no return air line and also no large number of valves for filling (essentially) cylindrical containers such as cans—it gets by anyway. Furthermore, it does not require any filling level correction and still enables pressure equalization or pre-tensioning and filling without complex measurement and control technology.

The filling device according to the invention and the method use the fact that cylindrical containers such as cans, which, alongside bottles and cartons, represent the most important packaging for beverages, especially for carbonated beverages such as beer or soft drinks, have an extremely precisely manufactured cylindrical shape - and thus an exactly determinable volume - with a coaxial filling opening that is smaller than the container diameter. Unlike glass bottles and cartons, the volume of cans is always the same and is therefore known exactly in advance for cans of the same type, with the predetermined filling volume corresponding to the nominal volume, so that the container volume V _B can be regarded as predetermined.

Figures 1 to 10 show an exemplary embodiment of a filling device 10 according to the invention in different phases during a method according to the invention for filling a can body as a container 20. Since the figures show a sequence of the filling device in different method steps, not all reference numbers are allocated in each figure. However, due to the equivalence of the representations, the assignment to the undesignated components and objects is readily given.

1 shows a filling device 10 which, according to the invention, is designed without a return air line without a return air duct and without measuring equipment, and has a simple construction with a minimum number of valves. The container 20 to be filled can also be seen, which is a can body whose essentially cylindrical shape tapers somewhat at the upper end towards the coaxial filling opening 21 . The taper serves primarily to accommodate the lid, not shown here, which is placed after the filling process has taken place and is connected to the edge of the can by flanging. The method according to the invention uses this difference between the inside diameter of the container d _i and the diameter d _Do of the container opening 21, which can be between 70 and 99.5%, for example, but is usually between 80 and 90% of the inside diameter of the container d _i for cans. In principle, however, a filling device according to the invention can also be provided for containers whose container opening diameter is significantly smaller than the container inner diameter, as is the case with bottles, for example, provided that they are manufactured with an exactly determinable diameter and volume.

The filling device 10 shown has a movable filling valve 1 which consists of a filling tube 2 and a piston 3 which is guided in a controllable manner. In the example shown, the filling valve 1 opens in that the piston 3 is moved upwards in relation to the filling tube 2 .

The filling valve 1 has an outer diameter d _Fa which is adapted to the diameter d _Do of the container opening 21 such that the filling valve 1 can be inserted through the container opening 21 into the container 20 without contact or friction. The method provides that the container 20 (as in 1 to be seen) is arranged in relation to the filling valve 1 in such a way that a coaxial, central insertion of the filling valve 1 through the container opening 21 into the container 20 is possible - this can be done by axially moving the filling valve 1 or the container 20, for example via a correspondingly movable Container recording (not shown) take place. Before the introduction, the container 20 with the container volume V _B is filled with ambient air (but possibly also another gas, e.g. inert gas or carbon dioxide) at an initial pressure p ₀ (e.g. ambient pressure, or if necessary - if the filling takes place in a closed system takes place - preset outlet pressure).

Next is in 1 a predetermined section of the filling valve 1 for insertion into the container 20, which has the volume V _F , which according to the invention should be in the range of 49 to 99% of the container volume V _B and in the example shown makes up about 65% of the container volume V _B . The volume V _F of the portion of the filling valve 1 of a container-filling device combination intended for insertion into the container 20 is known and predetermined.

The filling device 10 shows an attachment pipe 4 which is arranged coaxially around the filling valve 1 and can be moved in a controlled manner relative thereto and independently of it. For this purpose, the filling valve 1 is slidingly mounted in the attachment tube 4 in a sealing manner by means of a sliding seal 6 . In the example shown, the sliding seal 6 is present circumferentially on a collar 5, which surrounds the filling tube 2 at a predetermined distance from the filling valve opening of the filling valve 1, at which the filling valve 1 opens. This predetermined distance from the collar 5 to the filling valve opening of the filling valve 1 depends on the length of the section of the filling valve 1 intended for insertion and thus on the height H of the container 20; because it is provided according to the invention that the collar 5 comes to rest on (or at a defined distance adjacent to) the annular shoulder 7 when the section of the filling valve 1 intended for insertion is completely accommodated in the container 20, i.e. in principle up to extends to the container bottom 22, as in FIG 4 you can see.

For sealing placement on the container opening 21 , the attachment tube 4 has an annular shoulder 7 on the front side, which is designed with a sealing seat 8 adapted to the container opening 21 . A corresponding sealing element is not shown in the exemplary representation.

The annular shoulder 7 of the attachment tube 4, the inner diameter of which is adapted here to the inner diameter d _i of the container 20, protrudes radially inward in order to be able to be placed on the container opening 21, the diameter d _Do of which is smaller than this inner diameter d _i . However, the annular shoulder 7 is dimensioned in such a way that an annular gap remains around the filling valve 1 in order to allow fluid communication, ie gas exchange, with the interior of the container.

In step a) of the method according to the invention for filling a cylindrical container 20 with a fluid, as in 2 indicated by the block arrow, the filling valve 1 is inserted into the container 20 up to a predetermined height h ₁ without the attachment tube 2 being moved. The gas present there (at a known outlet pressure p ₀ , eg ambient pressure) is displaced in the corresponding volume from the container 20 into the environment by the partial section of the filling valve 1 introduced into the container 20 . The height h ₁ is predetermined for each container-filling valve combination for which the volumes V _B and V _F are known, depending on the back pressure provided for the respective filling process, which is selected in relation to an intended filling pressure, as described below is explained.

In the next step b), the in 3 1, while the inflation valve 1 is maintained at the first predetermined height _h1 , the attachment tube 4 is moved relative to the inflation valve 1, indicated by the block arrow, and seated onto the container opening 21, with the sealing seat 8 sealingly gastight to the the container edge delimiting the container opening 21 rests. There is now, divided into the partial volume V _A1 in the attachment tube 4 around the filling valve 1 and the partial volume V _B1 in the container 20 around the filling valve 1, a defined quantity of gas within the container 20 and the attachment tube 4 at the known initial pressure p ₀ . As already mentioned, the filling device 10 with the sealing seat 8 on the attachment tube 4 is designed in such a way that fluid communication or gas exchange with the interior of the container is permitted, ie the partial volumes V _A1 and V _B1 in the attachment tube 4 and in the container 20 around the filling valve 1 are connected to one another via the annular gap which is present in the region of the container opening 21 or the annular shoulder 7 carrying the sealing seat 8 around the filling valve 1.

4 shows step c), in which the filling valve 1, as indicated by the block arrow, is inserted completely into the container 20 with the predetermined section, while the attachment tube 4 remains in the sealing position at the container opening 21. Complete insertion can mean, as in the example shown, that the filling valve opening of the filling valve 1 comes to rest on the bottom 22 of the container 20 . For this purpose, the filling valve opening of the filling valve 1 can be shaped in accordance with the shaped bottom 22 of the container 20 . However, it can also be provided, for example in order to reliably avoid damage to the base 22, that a certain, defined distance from the base 22 remains even when the filling valve 1 is fully inserted. With the movement of the filling valve 1, the amount of gas that was previously in the partial volume V _A1 in the attachment tube 4 around the filling valve 1 (see 3 ) was present, pressed through the collar 5 sealed with the sliding seal 6 out of the attachment tube 4 into the container 20, and compressed there together with the quantity of gas from the partial volume V _B1 into the annular gap 23 with the differential volume ΔV, which is in the container 20 by the fully inserted filling valve 1 and the difference between the container volume V _B and the volume V _F (see 1 ) of the filling valve section to be inserted. This results in an increase in pressure to the predetermined counter-pressure p _G , which is provided for the respective filling process as a function of a predetermined filling pressure p _F .

The counter-pressure p _G is thus not adjusted by supplying a tensioning gas, but is (based on the initially present outlet pressure po) determined by the height h ₁ to which the filling valve 1 is inserted into the container 20 in step a) before in step b) the container 20 is sealed with the attachment tube 4. The remaining parameters influencing the adjustable back pressure are the known and fixed dimensions or volumes of the container and the filling device. The predetermined height h ₁ to which the filling valve 1 is inserted is not limited to that in 2 and 3 shown insertion depth is limited, but is determined by the counter pressure p _G to be achieved.

The height h ₁ is preferably between the container opening 21 and the container bottom 22, but heights h ₁ ≧H are also included, ie the filling valve 1 in step a) also can be positioned at the level H of the container opening 21 or above if the sealing is carried out in step b) by placing the attachment tube 4 in place. The back pressure p _G , which is then achieved in step c) by the fully inserted filling valve 1, is greater the greater the predetermined height h ₁ is. Conversely, if the filling process does not require pressure filling, the filling valve 1 can already be fully inserted in step a) (the predetermined height h ₁ is thus the height of the container bottom 22), so that after sealing with the attachment tube 4 in step b) there is no pressure increase by further inserting the filling valve and the actual filling process in steps d) and e) thus takes place at the initial pressure p ₀ . In certain cases, however, it can also be advantageous for h ₁ to be chosen “too low” in order to deliberately set the back pressure p _G below the saturation pressure of the liquid. As a result, an intended initial foaming of the liquid can be generated. This foam on the annular surface of the fluid in the annular gap 23 creates a separation of the fluid and the air that is desirable in this case, which leads to reduced oxygen uptake.

Figures 5 and 6 show the filling process with steps d) and e): The filling valve 1 opens (block arrow in figure 5 ), so that the fluid flows into the annular gap 23 with a predetermined filling pressure p _F , while at the same time the opened filling valve 1 is moved upwards (block arrow in 6 ). Filling pressure p _F and back pressure p _G are chosen so that when the pressure equalizes between the filling pressure p _F and the back pressure p _G , the fluid level S is within the annular gap 23 at a defined distance above the filling valve opening of the filling valve 1 . In addition, the speed of the upward movement of the filling valve 1 is coordinated with the inflow speed of the fluid, so that the fluid level S is always above the filling valve opening of the valve 1 with the valve opening in the annular gap 23 and the lower-level filling process is achieved, which can be carried out very quickly. With the upward movement of the filling valve 1, a partial gas volume ΔV ₁ is released around the filling valve 1 within the attachment tube 4, which corresponds to the fluid volume flowing into the container 20, so that the sum of the partial gas volume ΔV ₁ in the attachment tube 4 and a partial gas volume ΔV ₂ in the container above the Fluid level S corresponds to the differential volume ΔV. Since this gas volume ΔV remains constant, the predetermined back pressure p _G also remains constant, as a result of which the filling device 10 according to the invention manages without any measuring means for controlling the filling process.

The only controlled upward movement of the filling valve 1 is for a given container-filling device combination depending on the filling pressure provided in each case set so that, as in 7 can be seen, in step f) the relative upward movement of the opened filling valve 1 is terminated when a second predetermined height h ₂ is reached, which is present in the region of the container opening 21 . The height h ₂ is selected in such a way that the volume of fluid then present in the container 20 corresponds to the predetermined filling volume. Since the counter-pressure p _G always remains constant due to the filling valve 1 slidingly mounted sealingly in the attachment tube 4, so that with a given filling pressure p _F as a result of the pressure equalization, the level of the fluid level S in relation to the filling valve 1 also remains constant, when the predetermined height h ₂ is reached reaches the predetermined filling volume in the container 20 without having to make any corrections, since due to the existing pressure equalization when the filling valve 1 stops, there is no further inflow of fluid, even if the valve 1 is still open before it, as in 8 shown, is closed.

In order to reduce or even avoid foaming when removing the sealed filling device when pressure filling carbonated fluids, as in 9 shown by the block arrow, in step g) the closed filling valve 1 is removed from the container 20, on the opening 21 of which the attachment tube 4 is still sealingly arranged. The upward movement of the filling valve 1 within the attachment tube 4 increases the partial volumes V _B2 and V _A2 available for the gas quantity in the system, so that the back pressure p _G is reduced to a predetermined relief pressure p _E , which can correspond to the outlet pressure p ₀ , before in step h) ( 10 ) the attachment tube 4 is also removed from the container opening 21, and thus the initial pressure p ₀ prevails, and the filling process for the respective container 20 is thus terminated. A next container 20 can then be supplied to be filled in the same way.

In order to further improve the filling process and to achieve quasi-laminar flow conditions, so that the fluid level in the gap volume rises smoothly and trapped gas bubbles are avoided, a further embodiment of the invention provides that the filling valve 1 has a flow guide structure 9 that directs the outflowing fluid into a defined eddy or whirlpool movement offset. This avoids the fluid escaping at filling pressure colliding radially with the container wall and sloshing back, which means that more gas bubbles are trapped, which would accumulate until the end of the filling process and then lead to severe foaming.

The flow guide structure can, like 11 shows on an inside of the filling tube 2 or, as in the examples of Figures 12 to 14 on an outside of the piston 3 above the respective sealing surfaces 2', 3'. Contrary to what is shown, cooperating flow guide structures can also be present on both the filling tube and the piston, just as the filling valve can be a filling valve that opens to the outside.

The examples in 11 and 12 show a flow guide structure 9 in the filling tube 2 and on the piston 3, which is formed by a helical web similar to a thread. It is also possible to provide several helical webs running in parallel.

13 and 14 show blading as flow guide structures on the outside of the piston 3. Contrary to what is shown, blading can also be present on the inside of the filling tube.

The flow-guiding blading 9 on the piston 3 in 13 is formed by a ring of guide vanes, which are curved at least in two planes in order to put the fluid flowing past into a vortex or eddy movement.

14 shows an example in which the flow-guiding blading 9 is formed by a ring of rotor blades, which are not curved here. In order to set the fluid flowing past into a vortex or eddy movement, the piston 3 is designed to be driven in rotation, as indicated by the block arrow. If the rotor blades are curved, it is sufficient if the piston 3 is rotatably mounted, since the fluid flowing past the rotor blades causes the piston 3 to rotate, whereby the formation of vortices or eddies is supported even without a drive.

Apart from the simple construction without a return air line and the necessary valves and without complex measuring and control technology for preloading and pressure equalization, the filling device according to the invention offers the advantage that the contact of the fluid with atmospheric oxygen is reduced even without previous evacuation or gas flushing. This is due to the fact that the contact surface of the fluid in the annular gap around the filling valve in the container is merely an annulus with an annular width which is the difference between half the inside diameter of the container d _i and half the outside diameter of the filling valve d _Fa . Due to the lower-level filling process, in which the fluid level in the annular gap is always above the end face or the filling valve opening of the filling valve, the fluid only comes into contact with the gas present in the container at the annular contact surface. The circular ring represents an extremely small contact surface, which means that the absorption of gas (especially atmospheric oxygen) in the fluid is very low.

Any modification included within the scope of the invention, which is defined in the following claims, is intended to include:
According to the invention, the filling quantity is determined by the known geometries (volume) of the container (can) and the filling valve, which at the same time represents a displacement element, and the attachment tube. Various designs are conceivable for the filling valve. With the filling device according to the invention, expensive measuring devices such as MID sensors, as used in the prior art, can be dispensed with. There is also no need to control the filling based on the filling level, which is set by the position of the opening of a return air pipe or a return air hole or by means of sensors, actuators and suitable control logic. A level correction is not necessary.

With the geometric conditions of the filling device - the size of the ring-shaped surface between the container wall and the filling valve depends on the container diameter and container opening diameter and can therefore be very small - the contact surface is reduced, which results in reduced gas absorption in the filled fluid. While in the prior art the ambient air in the container is flushed out by carbon dioxide, which causes a very high consumption of carbon dioxide, the amount of oxygen is already significantly reduced here by the mechanical displacement of the air from the container as a result of the geometric conditions. Due to the layered filling process around the filling valve, in particular in the embodiment with the flow guide structure, there is little or no turbulence of the filled fluid and residual gas in the container, as a result of which the oxygen uptake is further minimized.

Furthermore, the back pressure required for pressure filling, which is generated in the prior art by compressed gas, usually carbon dioxide or nitrogen, is provided mechanically by sealing the filling opening during insertion of the filling valve, so that tensioning gas and corresponding devices for feeding can be omitted. The desired pressure can be set simply by determining the required insertion depth given the given geometric conditions.

According to the invention, a pressure filling without a return air tube is made possible, which means that the separate control, cleaning and maintenance of the return air tubes or return air lines is no longer necessary, which is still required in the prior art: a one-chamber principle is usually used there used for filling. The container to be filled and a storage container on the filling device (ring bowl) form a chamber during the actual filling process. The liquid flowing into the container to be filled displaces the gas present there into the reservoir. The known multi-chamber solutions have not yet become established, since the individual chambers can only be correctly separated if a loss of filling material is accepted. A real separation of the chambers is only possible in terms of equipment.

All in all, when filling containers such as cans, the invention makes it possible to dispense with both measuring devices for monitoring the filling quantity and flushing or tensioning gas, with the filling device used having a very simple design and hardly being error-prone. But even if the invention preferably manages without flushing and tensioning gas, the implementation of such steps in the method according to the invention is not ruled out.

Known quantities that do not change before, during and after the filling process are used in this invention. It is crucial that these variables cannot be changed or regulated. The can volume and the displacement volume of the filling valve remain the same and cannot be controlled. These geometric variables are determined (measured or calculated) at any time and used at another point in time to determine the pressure and (filling) volume during the filling process. The other basic parameter required for controlling the filling device is the outlet pressure, which is either set in a predetermined manner in a closed system or, if it is the ambient pressure, is currently determined, the penetration depth of the filling valve at the time of the sealing with the extension tube, which determines the back pressure.

Claims (5)

1. A filling arrangement, consisting of a filling device (10) and a predefined cylindrical container (20), which is a can (20) and the container opening (21) of which has a diameter (d_D0), which is smaller than the inner diameter (d_i) of the predefined container (20) by a predefined measure, wherein the filling device (10) has a filling valve (1), which has a piston (3) controllably guided in a filling tube (2) and an outer diameter (d_Fa), which is formed to be adapted to the diameter (d_Do) of the container opening (21) for coaxially inserting the filling valve (1) into the container (20) through the container opening (21), so that a portion of the filling valve (1) predefined for inserting into the container (20) has a volume (V_F) in the range of 33 to 99% of the container volume (V_B), wherein the filling valve (1) can be moved relative to a container receptacle, which is formed for receiving the container (20),

   wherein the filling device (10) has an attachment tube (4), which is formed for the sealing attachment to the container opening (21) and which is arranged coaxially around the filling valve (1) and can be moved relative thereto, wherein the filling valve (1) is mounted in the attachment tube (4) in a sealing manner by means of a slide bearing,

   characterised in that

   for being mounted in the attachment tube (4) in a sealed manner by means of a slide bearing, the filling valve (1) has a collar (5) with a diameter adapted to an inner diameter of the attachment tube (4), and a sliding seal (6), which is arranged on the collar (5) on the outer circumference, in order to allow for the relative movement between the filling valve (1) and the attachment tube (4) and to simultaneously seal a space in the attachment tube (4) around the filling valve (1) to the top, towards a side facing away from the container (20),

   so that an amount of gas can be predefined, which consists of a partial volume (V_B1) in the container (20) and a partial volume (V_A1) around the filling valve (1) in the attachment tube (4), which is attached in a sealing manner to the container opening (21) by means of the collar (5) comprising the sliding seal (6) when the closed filling valve (1) is positioned at a predefined first height (h₁) with respect to the container (20) coaxially with the container opening (21),

   wherein the predefinable amount of gas can be compressed in an annular gap (23), which is present in the container (20) around the filling valve (1), to a predefined counter pressure when the filling valve (1) is inserted completely, and

   wherein a partial gas volume (ΔV₁), which corresponds to a fluid volume of the fluid flowing into the container (20), in the attachment tube (4) around the filling valve (1) by means of the collar (5) comprising the sliding seal (6) can be released during a relative upwards movement of the opened filling valve (1) within the container (20) and within the attachment tube (4) for allowing the fluid to flow into the annular gap (23), so that the predefined counter pressure (p_G) remains constant.
2. The filling arrangement according to claim 1,
   characterised in that
   the attachment tube (4) for the sealing attachment to the container opening (21) has an annular ledge (7) comprising a sealing seat (8) adapted to the container opening (21).
3. The filling arrangement according to claim 1 or 2,
   characterised in that
   the collar (5) is spaced apart from a filling valve opening of the filling valve (1) in such a way that the collar (5) comes to rest on the annular ledge (7) when the portion of the filling valve (1) provided for insertion is received completely in the container (20).
4. The filling arrangement according to at least any one of claims 1 to 3,
   characterised in that
   the attachment tube (4) has an inner diameter, which corresponds to the inner diameter (d_i) of the predefined container (20).
5. A method for filling a cylindrical container (20) with a fluid by using a filling arrangement according to at least any one of claims 1 to 4, comprising the steps of

   a) positioning the closed filling valve (1) with respect to the container (20) coaxially with the container opening (21) at a predefined first height (h₁),

   b) attaching the attachment tube (4) in a sealing manner to the container opening (21), wherein a predefinable amount of gas remains, which consists of a partial volume (V_B1) in the container (20) and a partial volume (V_A1) in the attachment tube (4), which is sealed around the filling valve (1), and which is sealed by means of the collar (5) comprising the sliding seal (6) around the filling valve (1),

   c) completely inserting the filling valve (1), so that the predefined amount of gas in an annular gap (23), which is present in the container (20) around the filling valve (1), is compressed to a predefined counter pressure,

   d) opening the filling valve (1) and allowing the fluid to flow into the annular gap (23) with a predefined filling pressure, so that a fluid level (S) within the annular gap (23) lies above the filling valve opening of the filling valve (1), and thereby

   e) performing a relative upwards movement of the open filling valve (1) within the container (20) and within the attachment tube (4), wherein the fluid level (S) within the annular gap (23) remains above the filling valve opening of the filling valve (1), and wherein a partial gas volume (ΔV₁), which corresponds to a fluid volume of the fluid flowing into the container (20), is released in the attachment tube (4), which is sealed around the filling valve (1) by means of the collar (5) comprising the sliding seal (6) by means of the upwards movement of the filling valve (1), so that the predefined counter pressure remains constant,

   f) ending the relative upwards movement of the open filling valve (1) when reaching a second predefined height (h₂), wherein the predefined filling volume in the container (20) is reached, and closing the filling valve (1),

   g) removing the closed filling valve (1) from the container (20) comprising attached attachment tube (4) and thereby lowering the counter pressure (p_G) to a predefined relief pressure,

   h) removing the attachment tube (4) from the container opening (21).

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