EP1497181A1

EP1497181A1 - Method and device for inert gas rinsing of containers

Info

Publication number: EP1497181A1
Application number: EP03722489A
Authority: EP
Inventors: Werner Grabher
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-04-24
Filing date: 2003-04-16
Publication date: 2005-01-19
Anticipated expiration: 2023-04-16
Also published as: EP1357035A1; ES2270019T3; DE50304476D1; WO2003091106A1; AU2003229681A1; NZ535923A; US20050252527A1; US20100064639A1; EP1497181B1; ATE334883T1; CN100396564C; CN1646373A; US8137480B2

Abstract

Process for rinsing a container with protective gas comprises introducing and removing the protective gas parallel to the surface of the filling opening of the container. The filling opening is connected in a leak proof manner to a channel used for introducing/removing the protective gas. An Independent claim is also included for a device used for carrying out the above process. Preferred Features: The incoming protective gas has a higher pressure and/or the outgoing gas has a lower pressure than the environment of the device.

Description

METHOD AND DEVICE FOR PURGLEING PROTECTIVE GAS FROM

CONTAINERS

The invention relates to a method and a device for protective gas purging of containers, in particular for food, according to the preamble of claim 1 and claim 7.

It is known that certain products, especially food products, are adversely affected by oxygen and / or air humidity. So they are kept in an artificial atmosphere with reduced oxygen and / or water vapor content.

For foodstuffs that are stored in flexible containers, a common packaging method is to evacuate the packaging with the products and then seal them gas-tight. This method is for containers with thin, in particular semi-rigid, walls, such as. B. cans, cups or bowls, not possible, since such containers usually do not withstand the forces that occur during evacuation.

Containers can be evacuated in a known manner in a vacuum chamber and then gassed with a protective gas, for example nitrogen. This multi-stage process requires a lot of equipment, energy and time. Only very sensitive and high quality food products such as B. milk powder, justify the use of such methods. From US 2 519 353 a closing station for a filled tin can is known, in which a device for water vapor flushing of the head space of the can is integrated. The device has a flow channel for water vapor. It is formed by walls of the device and the can lid to be attached to the can. The can lid is inserted into a hole in a wall of the channel. The channel ensures a controlled flow across the head space of the can from one side to the opposite side of the can opening. Such a flow results in a controlled gas exchange in the head space - without uncontrolled turbulence. This enables uniform evacuation of the air from the head space. In addition to the closure element, an air exchange carried out in this way also requires the can to be closed at the same station.

From DE 3925952 Cl a vessel sealing machine is also known in which filled glass bottles - driven by a continuously rotating rotary star - rotate on a circular path. The headspace is flushed with inert gas and closed with a crown cap. The flow chambers through which the inert gas flows are formed by two parallel walls that are attached to the rotary star. The lower and the upper wall each have a recess for the bottle neck or crown cap inserted into the chamber. This vessel sealing machine is suitable for the gassing and immediate sealing of rapidly circulating, filled glass bottles. The invention is based on the object of providing a method and a device with the aid of which a protective gas flushing for different types of containers, for example cans, is made possible. In addition, this method should be able to be used more flexibly in the same processing station compared to protective gas purging and subsequent closing. Last but not least, a protective gas flushing of containers is to be proposed, which is assigned to several, in particular ring-shaped, stations of a processing station for containers.

This object is achieved by a method or a device in which the characterizing features of independent claims 1 and 7 are realized.

Further advantageous or alternative embodiments of the invention are described in the features of the dependent patent claims.

When a container is mentioned in connection with the invention, it should be understood to mean a container which has at least one rigid or semi-rigid wall. In particular, this is to be understood to mean cans which have an essentially tubular wall. This wall is sealed gas-tight at one end and should be closed gas-tight at the other end after filling by means of a closure element.

In the method according to the invention for purging a container with protective gas, protective gas flows on the one hand into a channel delimited by walls and on the other hand out of the latter. The container is over with its filling opening a recess in a first wall delimiting the channel leads to the flowing protective gas in such a way that in the edge region of the filling opening the protective gas flows in and out directed essentially parallel to the surface of the filling opening. According to the invention, the channel in the area opposite the recess has flow limiting means which can be moved parallel to the first wall. These means can be designed as a further wall, as a filling device or as a closure element.

Depending on the speed and the amount of protective gas flowing and on the duration of the protective gas purging, gas from the can is displaced by the protective gas. As a result, a predetermined residual oxygen or residual water vapor content in the container can be reached or fallen below. If a device for detecting the oxygen content, for example in the interior of the container, is also provided in the device for protective gas purging, then the predetermined value for the residual oxygen content can be set in a self-regulating manner via feedback with the control elements which control the protective gas flow.

The wall of the channel opposite the filling opening can be designed in such a way that at least part of the protective gas, advantageously advantageously in a single direction, flows over the filling opening in the channel.

The inflowing protective gas advantageously has one

Overpressure, the outflowing inert gas has a negative pressure in relation to the environment. In this way, the Speed of the flowing protective gas can be increased without any appreciable pressure increase in the container.

A device according to the invention has a plurality of walls which delimit a channel. Shielding gas flows into this channel at one end and out again at the other end. The channel has inlet and outlet openings for the protective gas in the edge region of the filling opening. The protective gas flows in and out parallel to the surface of the filling opening over its edge area. The protective gas flowing in and out through the channel comes into contact with gas in the interior of the container through the filling opening. As a result, gas from the interior of the container is replaced by protective gas. The channel and the interior of the container form a purging chamber in which the protective gas purging takes place.

An embodiment of the invention provides an essentially slot-shaped, horizontally arranged channel for the protective gas flowing in and out. The channel is bordered by an upper and a lower wall. A washable

Container can be brought up to the flowing shielding gas via a recess in the lower wall. For a protective gas purging, the container is guided perpendicular to the direction of flow of the protective gas through the recess in the wall to the protective gas flow. Such a device for protective gas purging can be made relatively flat and can therefore also be installed on existing processing stations for containers.

Advantageously, containers brought up to the protective gas flow are connected to the lower wall via the outside of their tubular wall. This leaves the inside of the tubular wall and the face accessible with the filling opening for any machining processes. The tightness of the connection can be ensured by a sealing lip which lies all around on the tubular outside.

A further development of the invention provides for several stations that process containers in the same cycle to be assigned a device for purging with protective gas, which extends over several stations. In this way, for example, a can can be rinsed out at a protective gas purging station and transported to a further station, for example a sealing station, in a protective gas atmosphere without ambient air being able to penetrate the can. With such a protective gas purging device distributed over several stations, the purging process can also be carried out over several

Stations and if necessary be distributed on the conveyor line between these stations. The advantages that can be achieved are obvious.

In particular, stations arranged in a ring can be provided with a device for purging with protective gas in a simple and reliable manner through a channel for the flowing protective gas, the lower wall of which, for example, is movable and the upper wall of which is stationary.

Another embodiment of the invention provides - for example in the form of two perforated disks - a movable lower wall and a movable upper wall. The two perforated disks are held at a distance from one another by wedge-shaped spacers directed towards the center and, together with the perforated disks, form walls delimiting the inert gas flow. The invention is described in more detail below purely by way of example with reference to the figures in the drawing. The same parts in different exemplary embodiments, which perform the same functions, are given the same designations and reference symbols below. Show it:

Figure 1 shows a processing station for cans with several stations, a rotary star and an embodiment of an inventive

Protection gas purging device in top view

Figure 2 is a sectional view (II-II) detailed view of the device of Figure 1 in side view

Figure 3 is shown in section (III-III)

Detailed view of a filling station with a device of the processing station of Figure 1 in side view and

FIG. 4 shows a detailed view in section (IV-IV) of a closing station with a device of the processing station from FIG. 1 in a side view.

FIG. 1 shows a processing station for containers designed as cans, on which cans are processed in the same cycle at several stations, not shown. In addition to a table top 1, the stations and a conveyor designed as a rotary star 4, the processing station has an exemplary embodiment of a device for protective gas purging 5 according to the invention, which flushes cans with protective gas at three stations. In a manner known per se, by rotating the rotary star 4 about the axis of rotation 3 in the direction of the rotary arrow shown in FIG. 1, cans are conveyed from one station to the next. The cans are guided by a guardrail 6, which is attached to the table top 1.

The device for purging with protective gas 5 here has an upper housing 7, a perforated disc 8 which can be rotated about the axis of rotation 3 and a lifting device which is not shown in FIG.

The lifting device, which is designed in the form of an arcuate lifting track 9, has a lifting ramp 13 at one end and a lowering ramp 14 at the other end for lifting a can to be closed or for lowering a can provided with a closure element 22. The two ramps 13 and 14 are arranged in relation to the direction of rotation of the rotary star 4 in the region in front of or after the upper part 7 and are connected via a curved rod which has a rectangular cross section.

The perforated disc 8 here has the shape of an annular disc in which eight regularly arranged recesses 10 are provided. A can can be inserted into each of the recesses 10. The perforated disc 8 is arranged above the rotary star 4 coaxially with the star plate at a distance predetermined by the height of the cans. In Figure 1, the perforated disc 8 hides the outer contour of the rotary star 4, which is shown in dashed lines. The

Rotary star 4 and the perforated disc 8 perform the same rotary movements about the axis of rotation 3. Cans that the lifting ramp 12 or the when moving from one station to the next Pass down ramp 13, are pushed into or out of the recesses 10. This movement of the can relative to the perforated disc 8 is here perpendicular to the conveying direction. The cans are guided through the rotary star 4 and the guardrail 6.

The top housing 7, which is fixedly connected to the table top 1, has a ring segment-shaped basic shape and encompasses part of the top side 21, the inside and outside edge of the perforated disk 8 11 or gas discharge lines 12 are provided. At the position of the closing station, not shown, which is arranged at the end of the device with respect to the direction of rotation, the upper side of the upper housing 7 has an insertion opening 15, into which a closure element 22 is inserted, and a feed, which is only shown schematically further closure elements with which further cans can be sealed gas-tight. The space delimited by the upper housing 7 and the perforated disk 8 is delimited in the radial direction by three radial sealing lips 16 shown in dashed lines in FIG. The sealing lips 16 are fastened to the upper housing 7 and here delimit two channels 27 and 27 'in the radial direction. The channels 27 and 27 'direct the protective gas flowing in and out.

FIG. 2 shows a detailed view of a station for protective gas purging of the processing station shown in FIG. 1 in section along the plane II-II and a can 25 to be closed, which is inserted into a recess 10 via the lifting track 9, in a partial section in side view. On the table top 1 of the processing station is the upper housing 7 and the lifting track 9 attached. The perforated disk 8 is fastened to the rotary star 4 via a spacer ring 17. The perforated disk 8 has two holding disks connected to one another and a disk seal 18 arranged between them and projecting beyond the inner and outer edge of the perforated disk 8. In the area of the recesses 10, the washer seal 18 has punched-outs, the edges of which protrude into the recesses 10. The disk seal 18 rests on the one hand on the mutually facing inner sides of the upper housing 7 and on the other hand laterally on the tubular outer side 20 of the can 25 inserted here from below transversely to the conveying direction.

The area of the filling opening 26 of the can 25 extends approximately to the top 21 of the perforated disk 8. The

Filling opening 26 could also protrude somewhat above it. The upper side 21 and the inner surface 19 of the upper housing 7 opposite the filling opening 26 delimit a first channel 27 which directs the flowing protective gas. The can 25 with its filling opening 26 is brought to the first channel 27. In this case, protective gas flows into the first channel 27 via the protective gas supply line 11 and out of the latter via the gas discharge line 12. In the edge region of the filling opening 26, this channel 27 is essentially in a plane parallel to the surface of the filling opening 26

Shielding gas supplied on the one hand and discharged on the other hand. In this case, at least part of the flowing protective gas comes into contact with the gas located in the interior of the can 25 via the filling opening 26 and flushes it out of the can 25.

A channel 27, together with the interior connected to it via the filling opening 26, forms an inserted one Can 25 an essentially closed flushing space for the protective gas flushing. It goes without saying that the effectiveness of the protective gas purging is determined not least by the sealing of the purging space from the surroundings of the device.

FIG. 3 shows a detailed view of a filling station with a protective gas flushing of the processing station shown in FIG. 1 in section along the plane III-III and a can 25 that is filled with salted peanuts, for example, in partial section in side view.

The upper housing 7 has an opening in which a filling device 23 is attached. In addition to a funnel-shaped filling channel, the filling device 23 has a closing flap 24 shown here in the open state. The can 25 is filled here through the flowing protective gas. A protective gas atmosphere also advantageously prevails in the funnel-shaped filling channel.

FIG. 4 shows a detailed view of a closing station with a protective gas flushing of the processing station shown in FIG. 1 in section along the plane IV-IV and a filled can 25, which is to be closed with a closure element 22, in partial section in a side view.

The box 25 is filled here with the salted peanuts as an example. If the can 25 has been filled outside of the device for purging with protective gas in the ambient atmosphere, the purging with protective gas also includes the gas in the space between the individual peanuts. If the empty can 25 is already flushed out with protective gas and / or takes place Filling process in a protective gas atmosphere, the scope of the protective gas purging can be kept smaller before the can 25 is closed.

The closure element 22 is inserted into the insertion opening 15 in such a way that its lower edge approximates the inside 19 of the upper housing 7. Here, the closure element 22 forms part of the wall which lies opposite the filling opening 26 and delimits the flow. Laterally, it lies all around the insertion opening 15 and essentially seals it from the surroundings. The inside 19, the closure element 22 and the top 21 of the perforated disc 8 here delimit a further channel 27 'which directs the flowing protective gas in the device for protective gas purging in the closing station. The further channel 27 'also forms, together with the interior of the filled can 25, a substantially closed washing space for a protective gas flushing ge ass of the invention.

In this exemplary embodiment, the closure element 22 is a container base, which is pressed against the tube-shaped can wall and temporarily closed, for example by means of a stamp (not shown in FIG. 3). However, the can 25 could just as well be pressed by the appropriately designed lifting path with the filling opening 26 against the closure element 22 and pushed over the upper edge of the upper housing 7. The closure element 22, which is now freely accessible laterally from all directions, could easily be attached to the tubular wall using a conventional closure device and the can 25 could thus be finally closed. The gas-tight sealed can can leave the device without affecting the atmosphere in the interior of the can. When being transported to the next station, the can passes the descent ramp 14 and is guided out of the perforated disc 8 onto the table top 1.

Until the next closure element 15 is introduced into the insertion opening 15, air from the ambient atmosphere can penetrate into the further channel 27 ', which is formed here by the inside 19, the perforated disk 8 and the lip seals 16 - shown only in FIG. 1. If the next closure element 22 is inserted into the insertion opening 15, the air which has penetrated is flushed out again from the further channel 27 'by the protective gas flow. A next can to be sealed can be conveyed to the sealing station.

Claims

1. Process for protective gas purging at least one container (25), wherein

Inert gas flows into a channel (27) on the one hand and on the other hand flows out again, in such a way that the container (25) with its filling opening (26) is brought to the flow via at least one recess (10) in a wall (21) 'of the channel (27) the area of the filling opening (26) is oriented parallel to the flow direction in the channel (27), and the flow in the area opposite the recess (10) is limited by limiting means (19, 22, 24) of the channel (27), characterized in that, during a movement of the limiting means (19, 22, 24) parallel to the first wall (21), a protective gas purging of the container (25) is carried out at least temporarily.

2. The method according to claim 1, characterized in that at least part of the protective gas in the channel (27) - preferably essentially in a single direction - flows over the filling opening (26).

3. The method according to claim 1 or 2, characterized in that the protective gas in relation to the environment under excess pressure and / or flows out.

4. The method according to any one of the preceding claims, characterized in that the filling opening (26) when approaching the flow via the outside (20) of the container (25), with the channel via a seal (18).

5. The method according to any one of the preceding claims, characterized in that the filling opening (26) is connected to the channel (27) via a movement of the container directed transversely to the direction of flow of the protective gas flowing in and out.

6. The method according to any one of the preceding claims, characterized in that the container (25), even while it is conveyed between a plurality of stations (23) via a conveying means (4), is at least temporarily flushed with protective gas, preferably the container to Stations (23) are each processed differently.

7. Device for protective gas purging at least one

Container (25), which has a channel (27) into which the protective gas flows in and out again, which channel (27) has a first wall (21) which limits the flow and has at least one recess (10) through which the container (25) for flushing with its filling opening (26) can be brought up to the flow in such a way that the surface of the filling opening (26) for

Flow direction in the channel (27) is aligned parallel, and

Has limiting means (19, 22, 24) for the flow in the area opposite the recess (10), characterized in that the limiting means (19, ^■ 22, 24) are parallel to the first wall (21) is movable.

8. The device according to claim 7, characterized in that the limiting means (19, 22, 24) as a further wall (19), as a closing flap (24) of a filling device (23), or as a closure element (22) of the container (25) are trained.

9. The device according to claim 7, characterized in that the closing flap (24) or the

Closure element (22) are movably arranged in a recess (15) of a wall opposite the first wall.

10. Device according to one of claims 7 to 9, characterized in that a seal (between mutually movable regions (19, 21) of the channel (27) and / or between the outside (20) of the container and the first wall (21) 18) is provided.

11. The device according to one of claims 7 to 10, characterized in that the device has a device for detecting the oxygen content and an actuating element, the device for

Detection and the control element the supply and discharge of the protective gas can be regulated.

12. The device according to one of claims 7 to 11, characterized in that the device over several

Stages (23) at which the container (25) preferably each in different ways is processed.

13. The apparatus according to claim 12, characterized in that the device has a rotary star (4) as a conveyor between the stations (23), which forms the first wall (21).

14. The apparatus according to claim 13, characterized in that the stations (23) are connected to one another via the further wall (19).

15. The apparatus according to claim 14, characterized in that a plurality of channels are provided for the flow, between which a radial sealing lip (16) is arranged.

16. The device according to one of claims 13 to 15, characterized in that the device for supplying the protective gas on the center of rotation (3) of the rotary star (4) facing the device and

Means for discharging the protective gas are attached to the opposite side.