EP2630424B1 - Equipment for producing cooling packs consisting of a shell made of a porous material containing an amount of carbon-dioxide snow enclosed and retained inside the casing - Google Patents

Description

The present invention relates to the field of devices for packing dry ice in a plastic film.

It is known that products frozen, frozen or fresh, especially food, which must be kept at a controlled temperature of + 2 ° C to -20 ° C or less, without breaking their cold chain since cooling, freezing or freezing until their use, require warehouses, means of transport, and stores, equipped with refrigeration facilities, which are currently generally electric. However, in many cases it is impossible to transport the products without removing them from the refrigeration plant where they are stored, and the risk of a rise in temperature is important, especially if the weather conditions are unfavorable. In order to avoid such a rise in temperature during transport, it is usual to have such products in an environment maintained at controlled temperature in an isothermal enclosure. The temperature regulation is for example ensured by the slow sublimation of dry ice packaged in bags of perforated plastic film. Dry ice is a relatively inexpensive product with an interesting cooling capacity: 573 kJ / kg of snow. Its temperature of about -80 ° C ensures a relatively long shelf life of the products.

The document EP-717,246 discloses an installation according to the preamble of claim 1. As an illustration, reference may also be made to the document EP-1 186 842 which describes a device for automatic and continuous packing of dry ice in a plastic film.

We can also refer to the documents FR-2,604,243 , or EP-823,600 , or U.S. 5,271,233 which describe refrigeration blocks enclosing a mass of dry ice.

We can also refer to the document EP-1 090 259 which discloses a method and an apparatus for obtaining refrigeration blocks composed of an envelope made of a porous material (capable of withstanding low temperatures below the degree Celsius) containing a mass of carbon dioxide snow trapped and retained in the envelope, the envelope being made of a material presenting, indicates this document, an "air porosity of between 100 and 500 m ³ / m ² / min for an air pressure of about 196 Pa", for example polypropylene nonwoven.

A manual bagger is therefore an equipment allowing, from a source of liquid CO ₂ , to generate, by expansion, dry ice directly in bags made of porous material (generally woven polypropylene). The amount of snow can be adapted according to the injection time applied, and according to the supply pressure of liquid CO ₂ . The equipment available on the market generally attaches to being able to fill several bags simultaneously.

The injectors installed on the manual baggers available are, most often, made by pierced tubes.

By way of example, as schematically illustrated by figure 1 attached relative to the prior art, a feeding tube, connected in its upstream portion to a source of liquid CO ₂ feeds a set of injection clarinets, each facing a cell where must be positioned a bag to fill , and each connected in its upstream part to a solenoid valve (directly or via primary tubes on which they are welded).

Along the length of each clarinet is machined an injection port, and it is understood therefore that to change the injection rate, it was necessary to disassemble one or more clarinets and modify (re-machine ) the injection port, which represents a complicated implementation and not very flexible.

This prior configuration, however, provided a perfect rigidity, necessary for the comfortable placement of the bags and the removal of the bags.

One of the objectives of the present invention is then to propose a new installation making it possible to improve this question of flexibility, and in particular to achieve a greater ease of variation of the delivery ports according to the needs of variation of flow of the user site (site who fills bags).

• un ensemble d'au moins deux alvéoles, aptes chacune à accueillir et maintenir un sac à remplir ;
• un tube nourrisse, relié en sa partie amont à une source de CO₂ liquide,
• un ensemble d'au moins deux clarinettes d'injection, chacune en regard d'une alvéole où doit venir se positionner un sac à remplir, et chacune étant reliée en sa partie amont au tube nourrisse (préférentiellement au travers d'une électrovanne, une électrovanne pour chaque clarinette, le raccord sur l'électrovanne pouvant s'effectuer directement ou bien par l'intermédiaire d'un tube intermédiaire (dit primaire) dont la clarinette est rendue mécaniquement solidaire, par exemple par soudure).
• chaque clarinette comporte en une localisation sur sa longueur au moins un orifice d'injection, l'installation se caractérisant en ce que :
• l'extrémité de chaque clarinette, opposée à la nourrisse, se présente comme une extrémité obturée, en forme d'embout sensiblement arrondi ;
• chaque orifice d'injection, présent sur chaque clarinette, se présente comme un orifice fileté de diamètre D, apte à accueillir une buse d'injection par vissage ;
• chaque buse d'injection se présente sous la forme d'une forme au moins partiellement cylindrique (sur au moins une portion de sa longueur), creuse, cylindre creux dont le diamètre extérieur (fileté) est égal audit diamètre D (et donc compatible avec l'orifice d'injection de la clarinette sur laquelle on vient fixer la buse en question), et dont le diamètre intérieur d est comme il se conçoit inférieur à D.

As will be seen in more detail in the following, the installation proposed by the present invention comprises:

• a set of at least two cells, each able to receive and maintain a bag to be filled;
• a feeding tube, connected in its upstream part to a source of liquid CO ₂ ,
• a set of at least two injection clarinets, each facing a cell where a bag to be filled is to be positioned, and each being connected in its upstream part to the feeding tube (preferably through a solenoid valve), solenoid valve for each clarinet, the connection to the solenoid valve can be performed directly or via an intermediate tube (called primary) whose clarinet is made mechanically secured, for example by welding).
• each clarinet has at least one injection orifice in a location along its length, the installation being characterized in that:
• the end of each clarinet, opposite the nurse, is presented as a closed end, in the form of a substantially rounded tip;
• each injection orifice, present on each clarinet, is presented as a threaded orifice of diameter D, suitable for receiving an injection nozzle by screwing;
• each injection nozzle is in the form of an at least partially cylindrical shape (over at least a portion of its length), hollow, hollow cylinder whose outer diameter (threaded) is equal to said diameter D (and therefore compatible with the orifice of injection of the clarinet on which one comes to fix the nozzle in question), and whose internal diameter d is as it is conceived inferior to D.

• l'embout arrondi facilite l'introduction de la clarinette dans un sachet à remplir ;
• les buses d'injection ont un diamètre D, compatible avec celui d'un orifice d'injection d'une des clarinette de l'installation, en revanche on peut disposer d'une batterie de buses d'injection à diamètre intérieur d très varié pour un D donné, ce qui permet de faire varier aisément le débit d'injection selon les besoins du site utilisateur, il suffit pour cela de dévisser une buse donnée, à diamètre intérieur d₁ donné, pour passer à une buse à diamètre d₂ différent, plus faible ou plus élevé, le changement étant immédiat, sans intervention lourde, et a fortiori sans ré-usinage.
• Selon une mise en oeuvre préférée de l'invention, chaque clarinette de l'installation ne comprend qu'un seul orifice d'injection fileté en un endroit de sa longueur, mais on peut bien sûr envisager, sans à aucun moment sortir du cadre de l'invention, de disposer sur l'une ou plusieurs des clarinettes de l'installation, de plusieurs orifices d'injection filetés sur la ou les clarinettes considérées.

It will be understood from reading the above:

• the rounded tip facilitates the introduction of the clarinet in a sachet to be filled;
• the injection nozzles have a diameter D, compatible with that of an injection orifice of one of the clarinets of the installation, on the other hand it is possible to have a battery of injection nozzles with a very wide internal diameter for a given D, this which makes it possible to easily vary the injection flow rate according to the needs of the user site, it suffices for this purpose to unscrew a given nozzle, with an inside diameter d ₁ , to switch to a nozzle with a different diameter d ₂ , smaller or more high, the change being immediate, without heavy intervention, and a fortiori without re-machining.
• According to a preferred embodiment of the invention, each clarinet of the installation comprises only one threaded injection orifice at a location of its length, but it is of course conceivable, without at any time going outside the scope of the invention. the invention, to have on one or more of the clarinets of the installation, several threaded injection orifices on the clarinet (s) considered.

• Selon une mise en oeuvre préférée de l'invention, toutes les clarinettes de l'installation sont munies d'un orifice (ou le cas échéant de plusieurs), le diamètre D étant identique pour tous les orifices des clarinettes.

Indeed, the one-port configuration is preferred for all clarinets to minimize the risk of clogging by snow formation, while maintaining a perfect "fluid continuity" between the source of CO ₂ and the single orifice of each clarinet, but other situations and operating conditions could justify the presence of one or more clarinets with multiple orifices while not causing any risk of clogging, for example to cope with large flow rates.

• According to a preferred embodiment of the invention, all the clarinets of the installation are provided with an orifice (or possibly more than one), the diameter D being identical for all the orifices of the clarinets.

But here again, it may be envisaged, without at any time going beyond the scope of the invention, that one or more of the clarinets of the installation have an orifice which is not of threaded diameter D, but which is of threaded diameter. D ', higher or lower than D, which would make it easier to adapt to the varying needs of the user site.

By way of illustration, according to one of the embodiments of the invention, all the threaded orifices of the installation have a diameter D = 8 mm, and the screwable nozzles are of internal diameter d = 4 mm or 3 mm for example .

But according to another embodiment of the invention, one or more of the clarinets of the installation are provided with a threaded injection orifice whose diameter is 8 mm, while one or more of the clarinets of the The installation is equipped with a threaded injection orifice whose diameter is not 8 mm but 10 mm, which makes it possible to fit (screw in) nozzles of internal diameter of 5 or 6 mm.

According to an advantageous embodiment of the invention, the screwable injection nozzles are in the form of a hollow cylindrical body for only a part of their length, whereas they have a flared shape of conical type on the remainder of the nozzle (part opposite the part of the nozzle entering the corresponding injection port), flared bottom part which can then be externally smooth or not, the advantage of this provision being to limit the risk of screwing up at the end the nozzle in the threaded injection port with difficulty in extracting the nozzle when it should be changed.

• un ensemble d'au moins deux alvéoles, aptes chacune à accueillir et maintenir une enveloppe à remplir ;
• un tube nourrisse, relié en sa partie amont à une source de CO₂ liquide,
• un ensemble d'au moins deux clarinettes d'injection, chaque clarinette étant situé en regard d'une alvéole où doit venir se positionner une enveloppe à remplir, et chaque clarinette étant reliée en sa partie amont au tube nourrisse, préférentiellement au travers d'une électrovanne, directement ou bien par l'intermédiaire d'un tube intermédiaire dont la clarinette est rendue mécaniquement solidaire,
• chaque clarinette comportant en au moins une localisation sur sa longueur un orifice d'injection,

l'installation se caractérisant en ce que :

• i) l'extrémité de chaque clarinette, opposée à l'électrovanne, se présente comme une extrémité obturée, en forme d'embout sensiblement arrondi ;
• j) chaque orifice d'injection, présent sur une clarinette, se présente comme un orifice fileté de diamètre D donné, apte à accueillir une buse d'injection par vissage ;
• k) chaque buse d'injection se présente sous la forme d'une pièce cylindrique sur au moins une partie de sa longueur, cylindre creux dont le diamètre extérieur fileté est égal au diamètre D d'au moins l'un des orifices filetés d'au moins l'une des clarinettes, et dont le diamètre intérieur d est inférieur à D.

The present invention thus relates to an installation for obtaining refrigeration blocks composed of an envelope made of a porous material containing a mass of dry ice enclosed and retained in the envelope, the installation comprising:

• a set of at least two cells, each adapted to receive and maintain an envelope to be filled;
• a feeding tube, connected in its upstream part to a source of liquid CO ₂ ,
• a set of at least two injection clarinets, each clarinet being located opposite a cell where a shell to be positioned is to be positioned, and each clarinet being connected in its upstream part to the feeding tube, preferably through a solenoid valve, directly or through an intermediate tube whose clarinet is rendered mechanically secured,
• each clarinet having at least one location along its length an injection port,

the installation being characterized in that:

• i) the end of each clarinet, opposite the solenoid valve, is a closed end, shaped substantially rounded tip;
• j) each injection orifice, present on a clarinet, is a threaded orifice of given diameter D, suitable for receiving a screw injection nozzle;
• k) each injection nozzle is in the form of a cylindrical part over at least a part of its length, hollow cylinder whose threaded outside diameter is equal to the diameter D of at least one of the threaded orifices of at least one of the clarinets, and whose inner diameter d is less than D.

• la figure 1 est une représentation schématique d'une ensacheuse multi-sacs conforme à l'art antérieur, munie de clarinettes d'injection dans chaque sac (ensacheuse déjà décrite ci-dessus).
• la figure 2 est une représentation schématique d'une clarinette d'injection conforme à l'invention, adaptable sur l'installation de la figure 1.
• la figure 3 illustre un jeu de buses d'injection conformes à l'invention, à diamètre extérieur D fileté, et à diamètre intérieur d varié (et inférieur à D).
• la figure 4 illustre de façon schématique et partielle en section un exemple de buse d'injection qui présente un corps cylindrique creux sur seulement une partie de sa longueur, tandis qu'elle présente une forme évasée de type conique sur le reste de la buse (la partie de la buse opposée à la partie de la buse destinée à entrer dans l'orifice d'injection qui lui correspond).

Other advantages of the present invention will emerge more clearly in the following description, given by way of illustration but in no way limitative, with reference to the appended drawings for which:

• the figure 1 is a schematic representation of a multi-bag bagging machine according to the prior art, provided with injection clarinets in each bag (bagging machine already described above).
• the figure 2 is a schematic representation of an injection clarinet according to the invention, adaptable to the installation of the figure 1 .
• the figure 3 illustrates a set of injection nozzles according to the invention, outer diameter D threaded, and inner diameter d varied (and less than D).
• the figure 4 illustrates schematically and partially in section an example of injection nozzle which has a hollow cylindrical body on only a part of its length, while it has a flared shape of conical type on the rest of the nozzle (the part of the nozzle opposite the part of the nozzle intended to enter the corresponding injection port).

• son embout 13 obturé est de forme sensiblement arrondie;
• la présence, en une localisation de la clarinette (ici à 85 mm de l'embout arrondi) d'un orifice 12, fileté, unique, de diamètre D donné (par exemple 8 mm), apte à accueillir une buse d'injection par vissage.
• cet orifice 12 est en communication de fluide (canalisation interne 11) avec l'électrovanne qui correspond à cette clarinette et dont elle est rendue solidaire (électrovanne non représentée ici pour des raisons de clarté), par exemple par soudage sur une portion de canalisation intermédiaire entre la clarinette 10 et l'électrovanne.

We recognize on the figure 2 a schematic representation in section of an embodiment of an injection clarinet 10 according to the invention, adaptable to the installation of the figure 1 :

• its closed tip 13 is of substantially rounded shape;
• the presence, in a location of the clarinet (here at 85 mm from the rounded tip) of a single threaded orifice 12, of given diameter D (for example 8 mm), suitable for receiving an injection nozzle by screwing.
• this orifice 12 is in fluid communication (internal pipe 11) with the solenoid valve which corresponds to this clarinet and of which it is made integral (solenoid valve not shown here for the sake of clarity), for example by welding on a portion of intermediate pipe between the clarinet 10 and the solenoid valve.

According to one embodiment of the invention, all the clarinets of the bagger conform to the clarinet of the figure 2 (ie one clarinet hole, all clarinet holes have the same threaded diameter D).

And precisely, we visualize better thanks to the figure 3 a set of injection nozzles according to the invention, screwable on the injection orifices of the clarinets of the bagger, nozzles with outside diameter D threaded (here 8 mm), and with internal diameter d varied (for example 4 mm , 3 mm, 2 mm, or for example in a pitch of 0.1 mm ...), able to be screwed on the orifice 12 of each injection clarinet, easily and immediately.

If it is necessary, for the needs of the user site, to change the injection flow rate, it is then sufficient to change the nozzle, within the set of nozzles represented here, and therefore of the injection diameter in the bag, this of immediate way, without heavy handling, without welding etc ..., this for one or more of the clarinets of the bagger.

It can be pointed out that the fact of having a set of nozzles in steps of 0.1 or 0.2 mm is very advantageous, because this configuration facilitates the production of the same quantity of snow for each clarinet (deviation related to pressure loss between the ^first powered clarinet and the following), this by adjusting if necessary very finely the internal diameter of the nozzles connected to each other clarinets (this will be illustrated later in the present application).

If the screwable injection nozzles of the figure 3 are as a simple hollow cylindrical body over their entire length, as indicated above it is preferred to have nozzles having a portion of their length this hollow cylinder shape, but flaring down into the rest of the nozzle, part flared bass which can then be smooth or not, the purpose of this arrangement being to limit the risk of screwing the nozzle to the end in the threaded hole with difficulty in extracting the nozzle when it should be changed ( figure 4 below).

The invention is illustrated below by practical examples of implementation of the invention, obtained under the operating conditions detailed below.

• diamètre D = 8 mm
• ½ sphère du bout arrondi de diamètre 20 mm
• diamètre de la canalisation 11 = 5 mm

An installation of the type of figure 1 , to five clarinets, each clarinet being in accordance with the figure 2 :

• diameter D = 8 mm
• ½ sphere of rounded tip diameter 20 mm
• diameter of the pipe 11 = 5 mm

• Séquence :
  • Mise en pression de l'installation et purge en gaz (nettoyage des tuyauteries)
  • Mise en froid
  • Test à vide (sans sac)
  • Réglage des buses d (diamètre)
  • Réglage du temps d'injection
  • Injection
  • Pesage
  • Réitération des essais
• Paramètres testés
  • Fonctionnement : absence de bouchage
  • Reproductibilité des essais
  • Influence du temps d'injection

The protocol followed was as follows:

• Sequence
  • Pressurization of the installation and bleeding in gas (cleaning of the pipes)
  • Cold setting
  • Vacuum test (without bag)
  • Nozzle adjustment d (diameter)
  • Setting the injection time
  • Injection
  • weighing
  • Reiteration of the tests
• Parameters tested
  • Operation: no clogging
  • Reproducibility of the tests
  • Influence of the injection time

Based on a given injection time (50 s), the nozzle setting is performed to determine the optimum configuration to obtain the closest possible amount of snow between the bags.

• on observe une excellente reproductibilité des résultats obtenus dans le réglage suivant au fil de la répétition des essais :
  • -- > pression amont : 17 à 20 bars.
  • -- > diamètre interne d des cinq buses vissées sur l'orifice D de chacune des 5 clarinettes : respectivement 3,6 mm, 3,6 mm, 3,5 mm, 3,7 mm et 3,7 mm ;
  • -- > masse de neige chargée dans chaque sac pour les 50 secondes d'injection : respectivement 3780 g, 3800 g, 3890g, 3830g, et 3720g, d'où un écart de +/- 2% par rapport à la moyenne ce qui est remarquable (débit de neige : voisin de 4,6 kg/mn) ;
• on a également pu établir des abaques (pour un réglage de buses d donné et retenu comme étant optimal en termes d'homogénéité entre sacs, comme décrit ci-dessus) de quantité de neige chargée en fonction du temps d'injection (par exemple par pas de 5 à 10 secondes entre un temps de 20 secondes jusqu'à un temps d'injection de 50 secondes) donnant lieu à une droite, les caractéristiques de cette droite étant parfaitement reproductibles au fil de la répétition des essais, ce qui représente un outil extrêmement simple et pratique pour faciliter le travail ultérieur d'un opérateur ;
• on aura compris, sans qu'il soit nécessaire de beaucoup insister ici, que l'ensemble de ces essais avec changement à volonté des buses vissables étaient aussi aisés à réaliser seulement grâce à la structure de la machine conforme à l'invention (clarinettes, orifices « D », buses vissables « d » etc...), et qu'il en sera de même dans le travail quotidien d'un opérateur sur une telle machine conforme à l'invention.

The following conclusions can be drawn:

• excellent reproducibility of the results obtained in the following adjustment is observed over the repetition of the tests:
  • -> upstream pressure: 17 to 20 bar.
  • -> internal diameter d of the five nozzles screwed on the orifice D of each of the 5 clarinets: respectively 3.6 mm, 3.6 mm, 3.5 mm, 3.7 mm and 3.7 mm;
  • -> mass of snow loaded in each bag for the 50 seconds of injection: respectively 3780 g, 3800 g, 3890g, 3830g, and 3720g, resulting in a difference of +/- 2% compared to the average. is remarkable (snow flow: close to 4.6 kg / min);
• it has also been possible to establish charts (for a given nozzle setting d and selected as optimal in terms of homogeneity between bags, as described above) of the quantity of snow loaded as a function of the injection time (for example by no 5 to 10 seconds between a time of 20 seconds to an injection time of 50 seconds) giving rise to a line, the characteristics of this line being perfectly reproducible over the course of the repetition of the tests, which represents a extremely simple and practical tool to facilitate the subsequent work of an operator;
• it will be understood, without it being necessary to insist much here, that all these tests with change at will of the screwable nozzles were also easy to achieve only thanks to the structure of the machine according to the invention (clarinets, orifices "D", screw-on nozzles "d" etc ...), and that will be the same in the daily work of an operator on such a machine according to the invention.

Claims (7)

1. Installation for producing cooling blocks consisting of a casing made of a porous material containing a mass of carbon dioxide snow enclosed and retained within the casing, which comprises:

   - a set of at least two cells, each capable of accommodating and holding a casing that is to be filled;

   - a feed tube adapted to be connected at its upstream end to a source of liquid CO₂,

   - a set of at least two injection pipes (10), each pipe being located opposite a cell in which a casing that is to be filled will be positioned, each injection pipe being connected at its upstream end to the feed tube, preferably via an electrically operated valve, directly or via an intermediate tube to which the injection pipe is mechanically attached,

   - each pipe comprising an injection orifice at at least one location along its length (12),

   the installation being characterised in that:

   i) the end of each injection pipe, the opposite end to the feed tube, is a blanked-off end, in the form of a substantially rounded tip (13);

   j) each injection orifice (12) provided on an injection pipe takes the form of a threaded orifice of given diameter D, adapted to have an injection nozzle screwed into it;

   k) it comprises at least two injection nozzles, each injection nozzle taking the form of a component that is cylindrical over at least part of its length, a hollow cylinder the threaded external diameter of which is equal to the diameter D of at least one of the threaded orifices of at least one of the injection pipes, and the internal diameter d of which is less than D.
2. Installation according to claim 1, characterised in that all the pipes of the installation are each equipped with only one threaded injection orifice.
3. Installation according to claim 1, characterised in that one or more of the pipes of the installation are equipped with more than one threaded injection orifice.
4. Installation according to one of the preceding claims, characterised in that the diameter D is the same for all the threaded injection orifices of the injection pipes of the installation.
5. Installation according to one of claims 1 to 3, characterised in that the diameter D of the threaded orifices of the injection pipes of the installation is not always the same.
6. Installation according to one of the preceding claims, characterised in that the screw-in injection nozzles take the form of a hollow cylindrical body over their entire length.
7. Installation according to one of claims 1 to 5, characterised in that the screw-in injection nozzles take the form of a hollow cylindrical body over just part of their length, whereas over the rest of the nozzle, i.e. the part of the nozzle opposite the part of the nozzle able to fit into the injection orifice corresponding to it, they have a conically flared shape.

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