EP0979207B1 - Method and device for filling barrels - Google Patents

Abstract

Disclosed is a method for filling barrels (4), specially kegs, with liquids, wherein at least one gas is dissolved. The barrel (4) is pre-stressed using a gas before the liquid is filled. Liquid is then fed into the barrel (4) by means of a filling valve (2) pertaining to a filling station (1) and connected to a feed line (3, 8). During filling, the pre-stress gas contained in the barrel (4) is evacuated. In order to guarantee economical and ecological product processing, the pre-stress gas in the barrel (4) is pre-stressed at only a partial pressure which corresponds approximately to the saturation pressure of the CO2 or N2 which is dissolved in the filled liquid. The flow rate speed is measured in the product feed line and is directly adjusted by adapting the volumetric flow rate of said product.

Description

The invention relates to a method for filling containers, especially kegs, with liquids in which at least one Gas is dissolved, the container before filling the Liquid is biased with a biasing gas, then the Container via a connected to a supply line Filling valve fed to a filling station and during liquid of the filling process, the biasing gas contained in the container is dissipated, and a device for performing this Procedure.

Carbonated beverages, such as beer, only keep their CO ₂ in solution if the partial pressure of the gas CO ₂ above the liquid is at least as high as the saturation pressure in the liquid. If the gas pressure above the liquid is below the saturation pressure, the liquid loses CO ₂ , but if the gas pressure is significantly higher, there is a risk that additional CO ₂ will dissolve. The gas absorption is dependent on the differential pressure between the saturation pressure in the liquid and the partial pressure above the liquid, the time available for gas exchange, which is usually equivalent to the filling time of the container, and the size of the gas exchange surface, i.e. the Liquid surface. Due to the turbulence in the liquid during the filling process, the risk of gas absorption during filling is considerably increased. The gas exchange between the liquid and the superimposed gas atmosphere affects not only the CO ₂ , but also other gases present in the gas atmosphere, in particular oxygen, which is absorbed by the liquid according to the same laws. However, oxygen is an important factor for the quality of the product in liquids that can be damaged by microorganisms or whose durability is endangered by the oxidation of liquid components.

To put the product through a valve into the container, be it one Getting a bottle or a barrel is a differential pressure between the supply line and the inside of the container. The size of the Differential pressure determines the inflow speed of the Product. Usually the product is used to avoid Surface enlargement caused by turbulence initially filled lower speed, which then slowly increased becomes. For this purpose, the container is prestressed with a gas pressure, which is significantly above the saturation pressure of the in the liquid dissolved gas. The liquid to be bottled itself by tanks or pumps also at this pressure level held and fed to the filling machine. After tempering of the container to the pressure of the liquid supplied a connection between the container and the feed of the filling material manufactured. By controlled draining of the in the container Existing bias gas is the inflow of the product in the container. Here, the building up determines Differential pressure is the flow rate of the liquid. It is also known that towards the end of filling the Gas outlet is throttled and thereby the differential pressure between the inside of the container and the supply line decreases. this causes Towards the end of the filling process, a reduction in the filling quantity per unit of time, which means an exact shutdown when reached a target quantity is made possible. This known method is referred to as "return gas control". The advantage of this Regulation is that the gas pressure is above the liquid is above the product's saturation pressure at all times.

The preload pressure to be set is determined by experience. At the beginning of the filling process, the product is said to lose CO ₂ due to turbulence that results in local negative pressures. This creates a deliberate artificial foam on the surface of the liquid, the bubbles of which only contain the released CO ₂ and thus protect the product from contact with the oxygen-containing gas atmosphere above. During the further filling process, the turbulence and with it the local negative pressure disappear. The product absorbs CO ₂ again during the remaining filling time. The trick is, depending on the CO ₂ content, temperature, container size and calculated filling time, to achieve a balance between CO ₂ loss and recovery.

In addition to the fact that the container must be biased far above the saturation pressure in the return gas control and the draining must be carried out in a controlled manner in order to achieve a controlled filling speed, the reduction of the filling speed in the last filling section is problematic. If the liquid inlet pressure remains constant, the flow rate can only be reduced if the differential pressure is reduced. In the known methods, the gas outlet is throttled (or, in extreme cases, prevented) and waited until the rising fill level has increased the back pressure to the desired value by compressing the remaining gas volume in the container. This period can be significant, especially for beer kegs. A 50 1 keg usually has an inlet cross-section DN21 and a maximum filling speed of 2.5 l / sec at a differential pressure of 0.8 bar. If the keg is filled with 35 l, 15 l gas space must be compressed by 0.7 bar to reduce the speed. For this, 15 x 0.7 = 10.5 l of liquid and, due to the slowing filling speed, about 8 seconds of filling time are required. Fast, precise regulation is therefore not possible, particularly in the case of possibly fluctuating inlet pressures. The situation is even more critical if not only one gas (for example CO ₂ ) but two gases (for example CO ₂ and N ₂ ) are deliberately dissolved in the product. Nowadays, N ₂ is added to beer because it has a foam-stabilizing effect. The best example of this is stout beer, whose creamy, long-lasting foam is caused by the dissolved N ₂ released when tapped. However, N ₂ and CO ₂ have completely different solubilities and saturation pressure curves. While CO ₂ easily dissolves and is difficult to get out of solution, it is extremely difficult to get N ₂ into solution at all and very easy to remove N ₂ even with the slightest turbulence. The balance between degassing at the start of filling and resumption of the lost gas during filling is almost impossible to find in 2-gas systems. The quality of the product to be filled is therefore fluctuating. Attempts are made to compensate for this by keeping the ratio of the gas atmosphere CO ₂ to N ₂ different from the proportion of the dissolved gases. However, this compromise is only valid for one temperature or one container size and only for one product supply pressure. It is impossible to master these many factors and their tolerances in terms of control technology.

Another disadvantage of the return gas control is that the container has to be prestressed with gas, usually CO ₂ , far beyond the saturation pressure in order to achieve a pressure drop that is still above the saturation pressure even during the maximum lowering of the internal pressure during the filling process of the gas. Since the gas is then released into the atmosphere, this also results in increased consumption of the greenhouse gas CO _{2 in} addition to energy consumption. Furthermore, the operating personnel are burdened by the high CO ₂ emissions.

GB-A-2 116 530 is a generic method known, with the filling of the kegs with down reversed connection fitting, the liquid through the carbonic acid valve of the connection fitting flows in and that displaced gas is discharged through the epee. Does that work Finally, beer over the top of the riser is that Full barrel. To a low swirl and low foam as well above all, consistently accurate filling of beer into the kegs It is intended to allow filling in 3 phases perform, with a first predetermined in a start-up phase Liquid volume measured and slowly into the Keg is introduced in the subsequent quick fill phase second predetermined volume of liquid measured and is quickly inserted into the keg and being in the final Filling phase a third predetermined volume of liquid measured and slowly inserted into the keg becomes. The volume of liquid filled into the keg via an inductive sensor on the liquid line recorded and to an evaluation and switching electronics forwarded, within which the measurement voltage is digitized and a measurement indicator calibrated in "liters" for the total volume of the keg is fed. The one for the individual The desired volume of the filling phases can be set using a setpoint be specified. To the different filling volumes To achieve in the individual filling phases is in the Fast filling phase switched on another filling line. The basis of the known method is therefore the provision of two parameterizable volume limit values when they are reached switched between a large and a smaller filling line can be. The flow rate in the Product supply line is not regulated.

The object of the invention is therefore to a gentle filling enable and reduce the consumption of bias gas.

This object is essentially achieved with the invention solved that the biasing gas in the container only to one about the saturation pressure of one of the bottled ones Partial pressure corresponding to liquid dissolved gases is biased and that the flow rate in the Product supply line measured and by adjusting the Product volume flow is regulated directly.

In contrast to the prior art, this is slow at first Inflow of the product and increase in flow speed no longer indirectly at the end of the filling Modulating the Keginnendruck regulated, but it takes place direct regulation of the product volume flow.

There is a major advantage of this new process in that the installation of Product pressure sensors can be dispensed with entirely because of this No longer press to generate flow rate are decisive. This makes the use of these highly accurate and sensitive sensors and their measuring technology Calibration adjustment is no longer required.

In a container filled with back pressure gas can only very to react sluggishly to product pressure fluctuations by the Pressure of the relatively large gas volume by blocking or Release of the gas outlet is increased or decreased. The Pressure change depends on the slowly increasing product level in the container. In the present invention, however, despite changing product or gas back pressures by changing the flow cross-section the flow rate of the product into the keg stable on the hold the desired value.

The first, cold product flowing into the hot keg brings Residual quantities of atmospheric sterile vapor in the container sudden condensation. The previously used pressure modulating Procedures could not do this pressure collapse settle fast enough. The new process solves this task without difficulty and a controlled slow Flow towards the product, prerequisite for a gentle Bottling is guaranteed.

In a development of the invention can in a data processing unit different filling curves are stored the specific container sizes, fitting types, different Product temperatures and / or certain propellant gas proportions Take into account. The design of these curves happens through algorithms that are calculated or empirical can be obtained and the mentioned container components or Flow rates corresponding to product conditions assign automatically. New product-container constellations can thus optimize self-learning in this system Design and process filling profiles. The filling curves are used as setpoints for regulating the product volume flow.

In a preferred embodiment of this inventive idea can fill curves, for example with graphically interactive Systems, changed graphically during production and be adjusted.

The gas inside the container can then be easily removed Overflow valve pushed out by the inflowing product become. The previously expensive control engineering Apparatus are no longer necessary for this. With liquids with several dissolved gases the optimal gas composition can be can be set within the container, because during the Filling process over the entire time an equal pressure in the The inside of the container prevails. With conventional return gas control had the changing pressures inside the container during the Filling process in the different filling phases different Gas exchange behavior and thus an influence the product quality. This is through the invention completely fixed.

According to a preferred development of the invention, the Preload pressure within the container according to the Saturation pressure set after filling. background this inventive idea is the fact that beer kegs before the filling for sterilization can be steamed and the cold Product is filled into the still hot container. Here become 50 l in approx. 12 kg of metal at a temperature of 100 ° C Beer filled at a temperature of approx. 3 ° C. It turns out a mixing and equalizing temperature, which is the temperature of the product in the container by approx. 4 ° C compared to the supply temperature elevated. Of course, this changes the Saturation pressures of the dissolved gases, so that according to the invention value to be set to that of the product in the filled Containers must correspond. This question has been asked in the past never posed because the back pressure is always significantly above the saturation pressure.

An apparatus for performing the above Procedure with a filling station, which is via a feed line product liquid to be filled into the container and from the escaping from the container via a return gas line According to the invention, bias gas is removed Filling station a flow meter to determine the flow rate in the feed line of the filling station and an adjustable orifice to adjust the product volume flow on. This allows the volume flow at each filling station Completely independent of the filling quantity or filling level independent of the supply pressure of the product to be filled of the others that may be provided on the filling machine Filling stations can be set individually. In many cases there is also a simplification of the filling machines usually upstream pressure tanks and their control, since these also affect the optimal without influencing the product Gas mixture according to the conditions at saturation pressure can be adjusted.

The product volume flow is based on a regulator the flow rate determined by the flow meter as actual value and one preferably to the container size, Fitting type, product temperature and / or proportion of propellant gas Product coordinated, in a data processing unit stored filling curve regulated as setpoint. For this is the Aperture cross-section can be changed continuously according to the invention.

According to a preferred embodiment of the invention Return gas line provided an overflow valve through which the Return gas is discharged.

Further training, advantages and possible applications of Invention also result from the following description an embodiment and the drawing. In doing so all described and / or illustrated features for itself or in any combination the subject of Invention, regardless of its summary in the Claims or their relationship.

Fig. 1

eine schematische Darstellung einer Füllstation gemäß der Erfindung,

Fig. 2

schematisch die Einflußgrößen für die Festlegung der Füllkurven und

Fig. 3a,b

eine Gegenüberstellung der herkömmlichen Rückgasregelung und der erfindungsgemäßen Regelung.

Show it:

Fig. 1

1 shows a schematic illustration of a filling station according to the invention,

Fig. 2

schematically the influencing variables for the definition of the filling curves and

3a, b

a comparison of the conventional return gas control and the control according to the invention.

The filling station 30 shown in Fig. 1 builds on that in the Master application DE 197 18 130.9, the content of which also for Subject of the present application is made described Principle of low gas back pressure in the too ventilating container. The filling station 30 consists in essentially from a filling valve 2, via a supply line 3 a liquid, such as beer, dissolved in the gases are fed. There is a container on the filling valve 2, in particular a keg 4 placed with the product liquid should be filled.

One of the individual filling stations 1 is located in the feed line 3 assigned flow meter 31 for determining the flow rate of the product through the line section 8 and an infinitely variable orifice 32, for example a membrane control valve, intended. The one in front or behind the aperture 32 Arranged flow meter 31 provides the data obtained of the product flow to an actual value processing 33 which the current flow rate (speed) as actual value a control device (34) passes on.

In the keg 4, a riser pipe 9 is provided, which with a Return gas line 10 of the filling valve 2 is connected. The Return gas line 10 leads to an overflow valve 11, via the access to a return gas outlet 12 is controlled. To the Return gas line 10 is also a bias gas line 13 connected, which can be shut off via a valve 14.

To fill the container 4, this is first biased via the biasing gas line 13 and the return gas line 10 with a biasing gas, in particular CO ₂ . In the case of certain liquids, for example stout beer, the biasing gas can also be a composition of several gases, such as CO ₂ and N ₂ . The preload pressure in the keg 4 is only at a partial pressure corresponding to the saturation pressure of the CO ₂ (or N ₂ ) in the beer or slightly above (e.g. 1.4 bar), which is below the product pressure in front of the filling valve 2 (e.g. 2nd , 5 bar) lies in the line section 8 of the supply line 3. The back pressure of the biasing gas in the keg 4 corresponds to the saturation pressure of the dissolved gas after the keg 4 has been filled, ie in the filled container. It is taken into account here that the beer filled at a temperature of approximately 3 ° C. warms by approximately 4 ° C. in the keg 4 which is usually steamed before filling and is therefore hot at approximately 100 ° C. The change in saturation pressure caused by this is already taken into account when setting the original preload pressure.

When filling, the control device 33 compares that of the Flow meter 31 delivered actual value with a constant one on the container size, fitting type, product temperature, Propellant gas proportion or the like. Parameters coordinated in one Data processing unit stored filling curve set Setpoint and changes the flow rate if necessary. To this end the infinitely variable aperture 32 is used, whose Cross-section through a linear drive (manipulated variable: stroke) can be varied so that a given one at any time Flow rate (controlled variable) can be generated. As a result, normal pressure fluctuations in the Product lines or the gas space balanced and through the compensated for very short controlled system without time delay become. In connection with a constant at the saturation pressure held back pressure can without further influencing the Product internal pressure in the supply line with large Precision given filling curves can be followed.

The influencing variables for the definition of the filling curves are in Fig. 2 shown. In addition to the calculated or empirically determined algorithms and in the Data processing unit stored fill curves, can new product / container constellations optimized for self-learning Filling profiles can be designed and processed. It can also be provided, the filling curves on graphically interactive To change systems during the production process.

3a, b show a comparison of the conventional "Return gas control" and the control according to the invention. While the indirect pressure control always runs counter to the flow rate takes place, being at the crossing points considerable regulatory problems arise with the direct control flow cross-section according to the invention (Volume flow) and flow velocity in parallel. On Pressure changes can be reacted to very quickly.

After closing the bias gas valve 14, the filling valve 2 opened, so initially only a small amount of product occurs on. Injecting the product is despite the pressure difference thereby avoided that the supply amount is targeted is reduced. Then the filling speed becomes slow increased so as not to cause excessive turbulence. The from the supply line 8 through the annular gap 15 in Filling valve 2 in the keg 4 beer presses that in Keg 4 contained bias gas through the riser 9 from the keg 4 out. The bias gas escapes through the overflow valve 11 in the return gas outlet 12. The through the overflow valve 11th The specified return gas pressure is, for example, a constant 1.5 bar.

An essential aspect of the invention is that the pretension in the keg 4 only has to be set to a partial pressure corresponding approximately to the saturation pressure of the CO ₂ (or N ₂ ) in the beer and is thus far below the conventionally set pretension pressure. Via the control unit 31-39 assigned to each individual filling station 30, it is possible to control the filling speed in the keg 4 without delay, so that filling with previously unattainable product protection is made possible. Damage due to unwanted loss or absorption of CO ₂ or the absorption of oxygen from the bias gas is avoided and the product quality is significantly improved with a 40% reduction in bias gas consumption.

Reference symbol list:

2nd

Filling valve

3rd

Supply line

4th

Keg

8th

Line section

9

Riser pipe

10th

Return gas line

11

Overflow valve

12th

Back gas outlet

13

Leader line

14

Valve

15

Annular gap

30th

Filling station

31

Flow meter

32

cover

33

Actual value processing

34

Regulator

Claims (10)

1. Method for filling barrels (4), especially kegs, with liquid, in which at least one as is dissolved, wherein the barrel (4) is pre-stressed with a pre-stress gas before being filled with liquid, wherein then liquid is fed to the barrel (4) by means of a filling valve (2) of a filling station (30), connected to a feed line (3, 8), and herein the pre-stress gas contained in the barrel (4) is removed during the filling process, characterized in that the pre-stress gas in the barrel (4) is only pre-stressed to a partial pressure, roughly corresponding to the saturation pressure of one of the gases dissolved in the liquid being filled, especially CO₂ or N₂, and that the flow speed is measured in the product feed line and con rolled directly by adjusting the product volume stream.
2. Method according to claim 1, characterized in that the flow speed in the feed line (8) is regulated on the basis of a previously determined filling curve that is stored in a data-processing unit.
3. Method according to claim 2, characterized in that filing curves corresponding to different barrel sizes, types of fitting, product temperatures and or proportions of propellant gas in the product are determined and entered into a data-processing unit.
4. Method according to claim 2 or 3, characterized in that the filling curves can be adjusted durinig the ongoing production, for example, with the help of graphic interactive systems.
5. Method according to any of claims 1 to 4, characterized in that the pre-stress gas provided in the barrel (4) is forced out from the barrel (4) by the inflowing product.
6. Method according to any of claims 1 to 5, characterized in that the pre-stress pressure in the barrel (4) is adjusted such that it corresponds roughly to the aturation pressure of the dissolved gas in the filled barrel (4).
7. Device for carrying out a method according to any of claims 1 to 6 with a filling station (30) with a feed line (3, 8), by which product liquid is supplied for filling a barrel (4) provided at the filling station (30), and with a return gas line (10), by which pre-stress gas escaping from the barrel (4) is discharged, wherein a flow meter (31) for determining the flow speed in the feed line (8) of filling station (20) and an adjustable diaphragm (32) for adjusting the product volume flow are provided at the filling station (30), characterized by a controller (34) which regulates the opening and closing of the diaphragm (32) on the basis of the flow speed determined by the flow meter (31) as the actual value and a filling curve stored in a data-processing unit as a set value.
8. Device according to claim 7, characterized in that a multiple number of filling curves is stored in the data-processing unit for various barrel sizes, types of fittings, product temperatures and/or propellant gas proportions in the product.
9. Device according to any of claims 7 or 8, characterized in that the diaphragm (32) is a membrane control valve.
10. Device according to any of claims 7 to 9, characterized in that an overflow valve (11) is provided in the return gas line (10), by which the return gas is discharged.

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