EP2969893B1 - Method for purging containers - Google Patents

Description

The invention relates to a method according to the preamble of claim 1 for rinsing containers with a purge gas.
Methods for filling, even pressure filling of containers are known in different designs. It is also known in this case to evacuate the respective container or its interior before filling and then to rinse with a purge gas formed by an inert gas (eg CO2 gas or serine air) to existing ambient air or another gas and / or vapor Remove medium from the container interior.

A generic method has been exemplified by the DE 199 39 521 A1 The proposed method is to evacuate PET bottles in a very short time, whereby the resulting negative pressure in the bottle should be above a pressure at which the PET bottles would implode. A disadvantage of this method is that it comes due to the high pressure in the PET bottle to a high consumption of purge gas.
The object of the invention is to provide a method which allows a particularly effective rinsing of the respective container interior with low consumption of purge gas. To solve this problem, a method according to claim 1 is formed.
A special feature of the invention is that when purging in a first process step, the container interior is evacuated by connecting to a vacuum source and then takes place in a second process step, the actual rinsing of the container by blowing the purge gas, wherein the container interior is further connected to the vacuum source, so that the blowing of the purge gas takes place in a vacuum or high vacuum in the container interior. The evacuation of the container in the first step of rinsing is carried out so that in the container, a pressure of about 0.05 - 0.4 bar, preferably a pressure of about 0.05 to 0.25 bar sets, ie, a negative pressure of about 0th , 6 bar - 0.95 bar, preferably 0.75 to 0.95 bar relative to the ambient pressure. The introduction or injection the flushing gas is then carried out with such a pressure and / or with such a flow that at most a pressure increase in the container interior at most 0.1 bar to 0.2 bar results.
The advantage of the method according to the invention consists inter alia in an effective rinsing of the bottle interior and in a significant reduction in the consumption of purge gas. Thus, the above-described method is compared with rinsing processes that are carried out under atmospheric or ambient pressure or at a pressure above atmospheric or ambient pressure, with up to 10 times lower purge gas or Spülgasmenge.
The lower consumption of purge gas or inert gas further represents a significant cost savings. Furthermore, with the rinsing method according to the invention, an oxygen uptake during the subsequent filling can be considerably reduced.

For the purposes of the present invention, containers are those made of glass, including glass bottles or similarly stable containers made of metal or plastic, such as kegs, party kegs, reusable plastic bottles, etc. It is essential that the containers used in the method according to the invention have sufficient stability so that they are not deformed or even destroyed to an undesirable degree during evacuation.
In sealing position with the treatment head or filling element befindlicher container means in the context of the invention that the respective container in the manner known to those skilled with its container mouth tightly pressed against the treatment head or to the filling element or to a local seal.
The expression "essentially" or "approximately" in the sense of the invention means deviations from the exact value by +/- 10%, preferably by +/- 5% and / or deviations in the form of changes that are insignificant for the function.

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and from the figures.

Fig. 1

in vereinfachter Darstellung und teilweise im Schnitt ein Füllelement einer Füllmaschine umlaufender Bauart, zusammen mit einem am Füllelement in Dichtlage angeordneten Behälter in Form einer Flasche;

Fig. 2

in vergrößerter Teildarstellung und im Schnitt die Unterseite des Füllelementes der Fig. 1 zusammen mit einer dortigen Zentriertulpe;

Fig. 3

sehr schematisch einen Querschnitt durch das Füllelement im Bereich einer Abgabeöffnung und eines rohrförmigen Ventilstößels sowie Rückgasrohres;

Fig. 4

in vereinfachter Darstellung und teilweise im Schnitt ein Füllelement einer Füllmaschine umlaufender Bauart, zusammen mit einem am Füllelement in Dichtlage angeordneten Behälter in Form einer Flasche, bei einer weiteren Ausführungsform der Erfindung;

Fig. 5

ein steuerbares Gasventil zur Verwendung bei einem Füllelement der Fig. 1 und/oder 4.

The invention will be explained in more detail below with reference to the figures of an embodiment. Show it:

Fig. 1

in a simplified representation and partly in section, a filling element of a filling machine of rotating design, together with a arranged on the filling element in sealing position container in the form of a bottle;

Fig. 2

in an enlarged partial view and in section the underside of the filling element of the Fig. 1 together with a centering tulip there;

Fig. 3

very schematically a cross section through the filling element in the region of a discharge opening and a tubular valve stem and return gas pipe;

Fig. 4

in a simplified representation and partly in section, a filling element of a filling machine of rotating design, together with a container arranged on the filling element in a sealing position in the form of a bottle, in a further embodiment of the invention;

Fig. 5

a controllable gas valve for use with a filling element of Fig. 1 and / or 4.

The generally designated 1 in the figures filling element is provided together with a plurality of similar filling elements on the circumference of a vertical machine axis MA rotatably driven rotor 2 and forms together with a container carrier 3 a filling for filling, for example pressure filling of containers 4 in the form of bottles 4. These are made of glass, metal or plastic with sufficient strength. On the rotor 2 a common Füllgutkessel 5 is provided in the form of a ring boiler for all filling elements 1 of the filling system or filling machine, which is partially filled during the filling operation with the liquid product, to form a lower liquid space 5.1 and an upper gas space 5.2, which is filled with an inert gas (eg CO2 gas or nitrogen) under filling pressure. The liquid space 5.1 is connected to a formed in the housing 6 of the filling element 1 liquid channel 7, which forms a vertical Füllelementachse FA concentrically enclosing annular discharge opening 8 on the underside of the filling element. In the liquid channel 7, a liquid valve 9 is further provided, which is formed on a valve stem 10 formed valve body 11 is axially movable by an actuator, for opening and closing of the liquid valve 9. The valve stem 10 is formed by a piece of pipe which is coaxially with the Füllelementachse FA disposed at its upper and at its lower, over the discharge opening 8 downwardly projecting end is open and forms a first gas channel 12 which opens at the upper end of the valve stem 10 in a housing 6 formed in the first gas chamber 13.

Axially with the Füllelementachse FA a return gas pipe 14 is further arranged, which serves as the filling level in the bottle 4 determining element and a second open at the bottom and at the upper end of the return gas pipe 14 when filling. The gas channel 15 opens at the upper end of the return gas pipe 14 in a second formed in the housing 6 gas space 16. The gas chambers 13 and 16 are part of different, the control valves 17.1 - 17.4 of the filling element 1 contained gas paths through which the gas channels 12 and 15 controlled by the Gas chamber 5.2 and can be connected to two annular channels 18 and 19, which are provided for all filling elements 1 of the filling machine or the filling system together.

The annular channel 18 serves, for example, to relieve the filled bottles 2 at the end of the respective filling process. The annular channel 19 is acted upon during the filling operation with a vacuum or negative pressure, for example at a pressure of 0.05 bar - 0.25 bar or deviating therefrom. The gas chamber 5.2 is charged during filling with the inert gas under pressure.

20 is a Zentriertulpe shown sealed by means of a seal against the underside of the housing 6 and abuts against the respective bottle 4 with the Pressed edge of its bottle opening in sealing position, so that the discharge opening 8 and the lower opening of the first gas channel 12 open into the upper region of the bottle interior. The return gas pipe 14 projects beyond the lower end of the valve tappet 10 into the interior of the bottle 4.

The peculiarity of the filling element or of the method carried out with this filling element consists in the special type and embodiment of purging the interior of the respective bottle 4 arranged in sealing position on the filling element 1 for displacing ambient air entrained in the bottle from the interior of the bottle. The subsequent process steps of the filling process, such as biasing the interior of the bottle with inert gas from the gas chamber 5.2 to the filling pressure, the pressure filling of the bottle 2 and the unloading of the filled bottle 2 to atmospheric pressure, for example in the annular channel 18 in accordance with e.g. usual, known methods.

The aim is an effective flushing of the bottle interior with low consumption of purge gas or inert gas. For this purge includes at least two steps. In a first method step is evacuated with closed liquid valve 9 and closed control valves 17.1, 17.2 and 17.4 via the open control valve 17.3, the gas space 13 and the gas channel 12, the interior of the bottle 2, for example, to a 95% vacuum or on a pressure in the range of 0.05 - 0.25 bar. In a second method step, the control valve 17.1 is then opened while the control valve 17.3 is still open, so that inert gas from the gas chamber 5.2 via the open control valve 17.1 and via a throttle 21 (fine throttle) in the gas chamber 16 and from this via the gas channel 15 centrally, ie in the direction of the filler element axis FA down as flushing gas into the interior of the bottle 4 and in the local high vacuum is blown. Since the return gas pipe 14 extends far into the interior of the bottle 4 down, the purge gas exiting the return gas pipe 14 also reaches the bottom of the bottle 4, for example and the displaced by this from the interior of the bottle 4 air discharged into the annular channel 19. With the help of the throttle 21, the purge gas flow or the flow rate of the purge gas are throttled so far that the negative pressure, the set at the end of the first process step when flushing in the bottle 4, only slightly increases, by about 0.1 bar - 0.2 bar. So that in the second process step, an internal pressure or scavenging pressure results in the bottle, which is still significantly below the ambient pressure, and for example about 0.15 bar - 0.45 bar.
To intensify the flushing, the supply of purge gas in the second step can be timed and without interruptions. Alternatively, the supply of purge gas but also at intervals, so take place in several sub-steps.
In both variants of the purge gas supply, it is of particular advantage that the connection of the interior of the bottle 4 with the vacuum leading annular channel 19 is always open, as the flushing of the interior of the bottle is particularly intense. However, this is not mandatory.
It is also possible to repeat the rinsing several times in total, in which case the method step 2 is repeated on a repetition of the method step 1, the options described above being available with regard to method step 2.
The Fig. 4 shows as a further embodiment, a filling element 1a, which differs from the filling element 1 only in that the control valve 17.1 on the input side is not connected to the gas chamber 5.2, but with a source 22, which provides the purge gas at least with a certain overpressure. Due to the separate source 22, the pressure of the purge gas can be selected independently of the filling pressure, in such a way that the desired low purge pressure is easily achieved.
Regardless of whether as inert gas CO2 gas or nitrogen is used, it is expedient to regulate the purge pressure in the interior of the bottle 4 via a pressure control to the desired pressure level and this with a arranged in the respective filling element, for example in the gas chamber 16 pressure sensor to monitor and / or control how he is in the Fig. 1 and 4 indicated by 23.

The regulation or control of the scavenging pressure then takes place, for example, by a control valve which is arranged in the corresponding gas path for the purge gas and which has at least two operating states, namely an operating state of low throttling and an operating state of higher throttling, but preferably also a third blocking state , Such a control valve 24 is in the Fig. 5 shown very schematically. The control valve 24 has a valve body 25 with a throttle-like narrowing flow channel 26 and an axially movable valve element 27, which releases the flow channel 26 depending on its position or additionally narrows or completely closes.
The invention has been described above by means of exemplary embodiments. It is understood that numerous changes and modifications are possible without thereby departing from the scope of the subordinate claims.
It has been assumed above that the rinsing of the bottles 2 or other containers takes place in a rinsing phase of a filling process with the filling elements 1 or 1a. In principle, the rinsing of the containers can also be effected via other treatment heads which are not filling elements, for example in a machine or component of a system preceding a filling machine.
Furthermore, it was observed that the rinsing process in a 0.5 l bottle, depending on the supplied gas volume flow, should preferably be carried out for about 150 to 300 ms, correspondingly longer for larger container volumes. In addition, only insignificant gas exchange processes were observed, or longer rinsing appear economically not useful.
It was found to be advantageous, however, if the optimum purging duration, at which flushing gas is injected, is interrupted one or more times by pause phases (no flushing of flushing gas) and the total duration of such pause times totals approximately 0.5 to 1.2 times the ( active) rinsing time is.

LIST OF REFERENCE NUMBERS

1, 1a

filler

2

rotor

3

container carrier

4

Container or bottle

5

Füllgutkessel

5.1

liquid space

5.2

headspace

6

casing

7

liquid channel

8th

discharge opening

9

liquid valve

10

tappet

11

valve body

12

gas channel

13

headspace

14

Return gas pipe

15

gas channel

16

headspace

17.1 - 17.4

control valve

18, 19

annular channel

20

centering bell

21

throttle

22

Source of purge gas

23

pressure sensor

24

Valve

25

valve body

26

flow channel

27

valve element

FA

filling element

MA

machine axis

Claims (13)

1. Method for purging containers (2) made of glass, metal, or plastic such as, for example, glass bottles, kegs, party barrels, reusable plastic bottles, with a purge gas prior to their filling, making use of a treatment head (1, 1a) on which the respective container (2) is arranged in a sealed position during purging and via which the purge gas is introduced into the container and the purge gas, as well as any gaseous and/or vaporous medium, for example air, displaced by the purge gas is discharged from the container, and wherein the container is evacuated before the purge gas is introduced or is subjected to a vacuum from a vacuum source (19),
   wherein, during the introduction of the purge gas into the container (2), the latter continues to be connected to the vacuum source (19), and the pressure and/or the volume flow of the purge gas introduced into the container (4) and the under-pressure of the vacuum source (19) are adjusted in such a way that

   - in a first method step, the container is set to a pressure in the range between 0.05 bar to 0.4 bar, preferably a pressure of some 0.05 to 0.25 bar, characterised in that

   in a second method step, following in temporal sequence, the purge gas is introduced or blown into the container, and specifically in such a way that the pressure in the container does not rise due to the introduction or blowing in of the purge gas, or only by 0.1 bar to 0.2 bar.
2. Method according to claim 1, characterised in that the pressure and/or the volume flow of the purge gas and the pressure of the vacuum source (19) are adjusted in such a way that, in the second method step, an internal pressure or purge pressure of between 0.15 bar and 0.45 bar is incurred in the container.
3. Method according to any one of the preceding claims, characterised in that the connecting of the container (2) to the vacuum source (19) takes place by way of a first gas channel (14) formed in the treatment head (1, 1a), and the introduction of the purge gas takes place by way of a second gas channel (15) formed in the treatment head (1, 1a).
4. Method according to any one of the preceding claims, characterised in that the introduction of the purge gas into the container (4) takes place centrically.
5. Method according to any one of the preceding claims, characterised in that the introduction of the purge gas into the container (4) takes place by way of a gas pipe or return gas pipe (14) extending into interior of the container.
6. Method according to any one of the preceding claims, characterised in that, as the purge gas, CO₂ gas or nitrogen is used, preferably from a gas chamber containing the purge gas under pressure and choked by a choke (21).
7. Method according to any one of the preceding claims, characterised in that the purge pressure in the container is monitored and/or controlled with the aid of a pressure sensor (23).
8. Method according to claim 7, characterised in that, with a treatment system with a plurality of treatment heads (1, 1a), the purge pressure for each treatment head (1, 1a) is monitored and/or controlled by an independent pressure sensor (23).
9. Method according to claim 8, characterised in that, with a treatment system with a plurality of treatment heads (1, 1a), the purge pressure for all the treatment heads (1, 1a) is monitored and/or controlled by one single pressure sensor (23) provided at one treatment head (1, 1a).
10. Method according to any one of the preceding claims, characterised in that the treatment head is a filling element (1, 1a) of a filling system for filling the containers (2) with a liquid filling product.
11. Method according to claim 10, characterised in that, with a filling system for the pressure-filling of the containers (2) from a filling product tank (5), which is under a filling pressure, the purge gas is provided from a source (22) which is independent of the filling product tank (5).
12. Method according to any one of claims 1 to 11, characterised in that, in the phase or method step in which purge gas is blown in, additional pause phases are provided by one or multiple interruptions of the purge gas.
13. Method according to claim 12, characterised in that the total duration of such pause periods amounts altogether to 0.5 to 1.2 times the purge duration during which purge gas is blown in.

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