FR2819235A1 - Food product package filler has coaxial tubes to deliver product and inert gas - Google Patents

Abstract

The filler (10) consists of a vertical guide tube (12) through which the product falls, topped by a mouthpiece or funnel (14) and surrounded at least partially by a coaxial outer tube (18) for delivering an inert gas through an inlet (20). The guide tube has perforations (46) at its lower end. The tubes and funnel are made from a material that does not interact with the gas, e.g. stainless steel.

Description

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 The present invention relates to a device for packaging products in packages, of the type comprising means for guiding the products to be packaged, defining a conduit for guiding the products into the packages, and a pipe for supplying packaging gas into the packages.

 Such devices frequently equip packaging machines for food products, the packaging of which is ensured, for example, with product inerting, by virtue of the substitution of ambient air inside the packaging by an inert gas by compared to packaged products. In the case of common foodstuffs, the inert gas often consists of nitrogen, carbon dioxide, argon or a mixture of these gases. Thus, devices of the aforementioned type are often part of vertical bagging machines which condition products such as salad, crisps or cookies in sachets. They can also equip horizontal packaging machines, in the case of products in trays for example.

 Such devices are generally in the form of a conduit for guiding the products to be packaged, inside of which at least one cannula ensures, by delivering a conditioning gas, the evacuation of the air present in the packaging. and accompanying the products. This cannula is in the form of a tube of small diameter compared to the dimensions of the guide duct and brings the gas into the packaging.

 However, the packaging of products by such devices leads to a certain number of difficulties.

 First, the presence of one or more cannulas hinders the progress of the products because they constitute a brake, or even a risk of blockage.

 In addition, in order to achieve low residual levels of undesirable gases inside the packaging, the devices mentioned require supplying large volumes of conditioning gas. It is admitted, for example,

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que l'inertage de produits conditionnés en sachets nécessite un volume de gaz inerte supérieur à trois, voire quatre fois le volume du sachet pour obtenir un taux d'oxygène résiduel inférieur à 2%.

that the inerting of products packaged in sachets requires a volume of inert gas greater than three or even four times the volume of the sachet to obtain a residual oxygen level of less than 2%.

Finally, these difficulties are particularly marked in the case of light or pulverulent products, such as food powders, or in that of products consisting of petals, such as crisps or puffed cereals. Indeed, these products are sensitive to the speed of the conditioning gas to which they are subjected: a high speed tends to lift them, which disturbs the formation of the packaging, in particular its closure by welding, and lengthens the conditioning times. .

The object of the invention is to prevent all of these drawbacks by proposing a packaging device of the aforementioned type, in which the supply of packaging gas practically no longer hinders the progress of the products, while notably reducing the volume of conditioning gas to be supplied.

According to the invention this object is achieved with a device of the aforementioned type, in which the gas supply pipe at least partially surrounds the product guide pipe.

According to other characteristics of the invention - the outside surface of the downstream part of the guide duct and the inside surface of the gas supply pipe define an inter-wall space; - The upstream end of the gas supply pipe is tightly fixed on the guide pipe; - The upstream end of the guide duct is provided with a product supply pavilion; - Perforations are made through the wall of the guide duct; - Perforations are made outwards through the gas supply pipe;

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- le conduit de guidage est constitué d'un tube de descente des produits, notamment sensiblement vertical, et la conduite d'amenée du gaz est constituée d'un tube, sensiblement coaxial à celui de descente ; - la conduite d'amenée du gaz est constituée d'un profilé creux à double paroi, à section en forme de U au moins partiel, les moyens de guidage étant formés par une paroi intérieure du profilé ; - le profilé creux forme une goulotte de guidage des produits ; - la goulotte est inclinée ; et - ledit gaz est un gaz d'inertage.

- The guide duct consists of a product downpipe, in particular substantially vertical, and the gas supply pipe consists of a tube, substantially coaxial with that of the downpipe; - The gas supply pipe consists of a hollow double-walled section, of at least partial U-shaped section, the guide means being formed by an inner wall of the section; - The hollow profile forms a product guide chute; - the chute is inclined; and - said gas is an inerting gas.

The invention also relates to a product packaging installation, of the type comprising means for forming and driving the packages formed around the products, and a device for packaging the products in the packages, characterized in that the device packaging is as defined above.

According to another characteristic of the installation, the packaging formation means comprise a pair of jaws for welding a packaging film, and the gas supply pipe constitutes the support for shaping the packaging film in progress. Welding.

The invention will be better understood on reading the description which follows, given solely by way of example, and made with reference to the appended drawings in which: - Figure 1 is a perspective view of a packaging device according to the invention; - Figure 2 is a perspective view of a second embodiment of a device according to the invention; - Figure 3 is a perspective view of a detail of a third embodiment of a device according to the invention; - Figures 4A and 4B are perspective views partially showing a packaging installation according to the invention comprising the

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dispositif de la figure 1 ; les figures 4A et 4B illustrent respectivement deux états de fonctionnement de l'installation ; - la figure 5 est une vue en perspective représentant partiellement une seconde installation d'emballage selon l'invention comportant le dispositif de la figure 2.

device of Figure 1; FIGS. 4A and 4B respectively illustrate two operating states of the installation; - Figure 5 is a perspective view partially showing a second packaging installation according to the invention comprising the device of Figure 2.

In Figure 1 is shown a first embodiment of a device 10 according to the invention. It is an inerting device.

This device 10 comprises a substantially vertical product descent tube 12. At its upper end, the downpipe 12 has a horn 14, or hopper, for supplying products converging downwards. The internal dimensions of the downpipe 12 and of the roof 14 are mainly dependent on the size and the nature of the products which they are intended to guide.

The device 10 further comprises a gas supply tube 18, substantially coaxial with the descent tube 12 and completely surrounding this tube. The gas supply tube 18 is provided on its outer surface with a gas supply orifice 20.

The lower end of the inlet tube 18 is substantially flush with the lower end of the downcomer 12, so that a wall space is formed between the inner surface of the inlet tube 18 and the outer surface of the tube downpipe 12. This inter-wall space 22 is open below, extends in height up above the gas supply orifice 20 and is closed in a sealed manner by the fixing of the gas supply tube 18 on pavilion 14.

The downspouts 12 and gas supply tubes 18, as well as the pavilion 14, are made of non-reactive material vis-à-vis the packaging gas. Various arrangements of these elements are possible; by way of example, these elements are made of stainless steel, the roof 14 being attached by welding to the downpipe 12 and the supply tube

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 18 also being added by welding at its upper end to the outlet of the roof 14.

 In FIG. 4A is partially shown an installation 30 for packaging in sachets, comprising the device 10 previously described.

 This installation 30 comprises an unwinder 32 of a roll 34 of packaging film 36. This film 36 is a plastic film fulfilling predetermined chemical stability criteria.

 The film 36 coming from the roller 34 is wound around the gas supply tube 18. The lateral edges 36A and 36B of the film extend on either side of the supply tube 18 to meet at a point 37, located below the level of the feed orifice 20. Below point 37, the film forms a tube 38 of film, shaped by the supply tube 18.

 The film tube 38 is closed on the one hand, by a horizontal welded junction 39, oriented transversely relative to the supply tube 18 and formed at regular intervals by the closing of a first pair of welding jaws 40, located at the below the device 10 and arranged transversely to the supply tube 18; and, on the other hand, by a vertical welded junction 41, oriented longitudinally and formed continuously by a second pair of welding jaws 42, arranged longitudinally in the supply tube 18, just below the junction point 37.

 In FIG. 4B, the same installation 30 as previously described is again shown, but during the supply of products 45 during an operating stage subsequent to that shown in FIG. 4A, as will be explained below. These products 45 are, for example, chips.

 The operation of the device 10 and of the installation 30 according to the invention are as follows.

 The film 36 is unwound from the roller 34 by means of the unwinder 32, so that this film 36 follows the external shape of the gas supply tube 18. The substantially middle zone of the film is applied along the tube 18, while that the edges 36A and 36B of the film each by one side bypass the

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 tube 18, as shown in Figure 4A. The edges 36A and 36B meet at point 37, just below which they are welded to each other by the pair of welding jaws 42, thus forming the longitudinal welded junction 41. The operation of the pair of jaws welding 42 will not be detailed since it falls within the prior art.

 Driving means, not shown, drive down the film tube 38 thus shaped around the supply tube 18.

 When the lower end of the film tube 38 is sufficiently distant, by a predefined distance, from the lower end of the device 10, the pair of welding jaws 40 closes transversely on the film tube 38 in order to achieve the junction welded 39. The operation of this pair of jaws 40 will not be detailed either since it falls within the prior art.

 During the formation of the welded junction 39, and, continuously or discontinuously, after the release of the pair of jaws 40, inert gas is injected into the gas supply tube 18 through the supply orifice 20. This gas is supplied by conventional injection means, not shown, so that it spreads inside the inter-wall space 22. The injection means deliver a gas under a slightly pressure higher than atmospheric pressure.

 The injected gas expels the air initially contained in the inter-wall space 22. Since the gas supply tube is tightly fixed at its upper end to the roof 14, the gas spreads downwards within space 22.

 The gas then escapes from the open lower end of the space 22 inside the film tube 38 closed by the welded junctions 39 and 41. In this way, the air initially contained in this film tube 38 is expelled by the flow of inert gas F1 generated at the outlet of the gas supply tube 18. The air thus expelled rises along the downpipe 12, inside of it.

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 The products 45 are then introduced into the downcomer 12, from its upper end, by means of the supply horn 14.

Under the effect of gravity, these products 45 are drawn down to the welded bottom 39 of the film tube 38.

 During the loading of products 45, the gas supply is maintained and the drive means of the film tube 38 again drive down the tube 38 during filling. This operation is shown in FIG. 4B, where the welded bottom 39 of the film tube 38 has been lowered by a height h relative to its initial formation position, located at the constant level of the pair of jaws 40.

 Once the loading of products 45 is complete, and while maintaining the supply of inert gas, the film tube 38 is driven downwards by a preset height so that the upper level of the products 45 loaded in the tube 38 either below the level of closure of the pair of jaws 40. This pair of jaws 40 then closes on the film tube 38 to form a new transverse welded junction 39, which will constitute both, for its upper part, a new bottom welded for a new packaging cycle as described so far, and, for its lower part, the upper closure of the bag thus produced.

 The flow of gas F1 at the outlet of the inter-wall space 22 is present throughout the conditioning cycle. As this flow spreads inside the film tube 38 along a large outlet surface, the flow F1 has a low speed, and therefore little turbulence, in this case much less than in the aforementioned cannula devices of the prior art.

 This slightly turbulent flow F1 proves to be particularly effective for evacuating the air initially contained in the film tube 38, and also the air which the products 45 tend to entrain when they descend into the film tube 38. Furthermore , the uniform peripheral arrangement of the outlet of the

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flux F1 garantit une meilleure homogénéité de la répartition du gaz inerte au sein des produits au cours de leur chargement dans le tube de film 38.

flux F1 guarantees a better homogeneity of the distribution of the inert gas within the products during their loading into the film tube 38.

The packaging in sachet described above leads to an excellent inerting capacity, with, for example, a residual oxygen content inside the closed sachet of less than 2%. This result is obtained with only a quantity of inert gas injected which is substantially equal to, or even less than, twice the volume of the sachet produced.

In addition, no element making it possible to bring the gas hinders the descent of the products 45 inside the descent tube 12, since the gas supply tube 18 is external to it.

This device is particularly advantageous for packaging in sachets of light products, in particular pulverulent products, or made up of petals mentioned above, since the low intensity of gas turbulence within the sachet being formed makes it possible to maintain a short cycle time, therefore a high production rate, without compromising the stability of product loading.

As a variant to this embodiment, and as shown in FIG. 1, the downpipe 12 is further pierced in its lower part by several orifices 46, thus allowing the passage of gas from the interwall space 22 to the inside the downpipe 12.

The operation of such a device is similar to the previous one.

The air initially contained in the film tube 38 is evacuated jointly by the flow F1 and by the flows F2, generated by the escape of the inert gas from the interwall space 22 in the inside the downpipe 12 through the orifices 46.

These flows F2, of less intensity than the flow F1, contribute to maintaining a slightly turbulent gaseous atmosphere inside the film tube 38 below the lower end of the product descent tube 12.

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 A variant not shown of the device 10 consists of providing perforations in the lower part of the gas supply tube 18. The gas escaping from these perforations is then trapped between the outside of the gas supply tube 18 and the film surrounding this tube 18. This gas contributes to the inerting of the interior surface of the film tube 38, while facilitating its downward entrainment.

 In Figure 2 is shown a second embodiment of a device 100 according to the invention.

 The device 100 comprises two hollow sections 101, 102, with double wall, of substantially rectangular cross section. These two sections 101, 102 are arranged symmetrically one opposite the other, by fixing means which are not shown, so that their respective walls facing one another, 111, 112 form a guide duct 113 for direction longitudinal parallel to that of the sections 101,102.

 This conduit 113 is used to guide products in the direction indicated by the arrow S. The upstream end, relative to the direction of product guidance, of each of the sections 101, 102 is hermetically closed, while the downstream end of each of them is open, so that each section 101,102 respectively defines between its walls an inter-wall space 121, 122 open downstream.

 Each inter-wall space 121, 122 communicates with a respective orifice 119, 120 for supplying gas, with a function similar to the supply orifice 20 of the preceding device 10.

 The internal walls 111,112 of the sections 101,102 extend longitudinally, in the opposite direction to that indicated by the arrow S, beyond the closed upstream end of each of the sections 101,102.

 Two similar plates 114, 115, substantially rectangular, are attached to the upstream end of the walls 111, 112. These plates 114, 115 are not longitudinally aligned with the interior walls 111, 112, but on the contrary, diverge upstream of the device, so that they

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 define a feed area or pavilion with a larger section than that of the guide duct 113.

 Advantageously, the internal walls 112, 113 are each, in their downstream part, perforated with holes 146, of function similar to that of the perforations 46 of the preceding device 10.

 FIG. 5 shows an installation 300 for packaging in sachets comprising the device 100. It is a substantially horizontal installation, suitable for the packaging of products 345 driven by a supply conveyor 301 and a conveyor Expedition 302.

These conveyors are only schematically represented. 345 products are, for example, buns ready to be inerted and packaged.

 This installation 300 also includes the same additional elements as the installation 30 previously described; these common elements are referenced by the same numbers.

 The operation of the device 30 is similar to that of the device 10, just as the operation of the installation 300 is analogous to that of the installation 30.

 However, it is also necessary to carry the products along arrow S during their packaging by means of conveyors 301 and 302, according to arrangements known in the art.

 In Figure 3 is shown a third embodiment of a device 200 according to the invention.

 This embodiment differs from the previous one only at the level of the profile used, since a profile 203 with double wall and cross section in the shape of an inverted U is now used. This amounts to connecting by an upper plate 204 with double wall the two sections 101 and 102 of the second embodiment. The device 200 then has a single inter-wall space 222 with an inverted U-section, as well as a product guide duct 213 formed by the walls 111, 112 and the interior wall 212 of the plate 204.

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 The operation of the device according to this third embodiment is analogous to that of the device according to the second embodiment.

 A variant which is not shown consists in using the device 200 within an installation substantially similar to the installation 300, but by turning the device 200 over so that its section has a straight U-shaped profile.

 Thus, by installing such a device so that its upstream end is located higher than its downstream end, the products can be entrained inside the device 200 by simple gravity.

 Finally, it should be noted that a device according to the invention is applicable for packaging in packages other than sachets. Thus, the invention is for example applicable, without departing from its scope, to devices for packaging products by filming, or to packaging products in trays.

Claims (7)

CLAIMS 1. Device for packaging products in packages, of the type comprising means (111, 112; 111, 212, 112) for guiding the products (45; 345) to be packaged, defining a conduit (12; 113; 213) for guiding the products to the packaging, and a pipe (18; 101, 102; 203) for supplying conditioning gas to the packaging, characterized in that the gas supply pipe (18; 101, 102 ; 203) at least partially surrounds the product guide duct (12; 113; 213). 2. Device according to claim 1, characterized in that the outer surface of the downstream part of the guide duct and the inner surface of the gas supply pipe define an inter-wall space (22; 121, 122, 222) . 3. Device according to one of the preceding claims, characterized in that the upstream end of the gas supply pipe (18; 101, 102; 203) is tightly fixed on the guide pipe (12; 113 ; 213). 4. Device according to one of the preceding claims, characterized in that the upstream end of the guide duct is provided with a pavilion (14; 114, 115) for supplying products (45; 345). 5. Device according to one of the preceding claims, characterized in that perforations (46; 146) are formed through the wall of the guide duct (12; 113; 213). 6. Device according to one of the preceding claims, characterized in that perforations are formed towards the outside through the gas supply pipe (18; 101, 102; 203). 7. Device according to one of the preceding claims, characterized in that the guide duct consists of a downpipe (12) of the products (45), in particular substantially vertical, and characterized in that the supply pipe gas consists of a tube (18), substantially coaxial with that of descent (12).