(19)
(11) EP 3 318 825 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
29.12.2021 Bulletin 2021/52

(21) Application number: 16020427.7

(22) Date of filing: 02.11.2016
(51) International Patent Classification (IPC): 
F25D 3/10(2006.01)
(52) Cooperative Patent Classification (CPC):
F25D 3/10

(54)

METHOD AND APPARATUS FOR COOLING OBJECTS WITH A CRYOGENIC LIQUID USING FLUIDIC OSCILLATING NOZZLES

VERFAHREN UND VORRICHTUNG ZUM KÜHLEN VON GEGENSTÄNDEN MITTELS EINER KRYOGENEN FLÜSSIGKEIT MITTELS OSZILLIERENDEN FLUIDSEPARATIONSDÜSEN

PROCÉDÉ ET APPAREIL DE REFROIDISSEMENT DES OBJETS PAR LIQUIDE CRYOGÉNIQUE VIA DES BUSES DE PULVÉRISATION OSCILLANTES


(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(43) Date of publication of application:
09.05.2018 Bulletin 2018/19

(73) Proprietor: Linde GmbH
82049 Pullach (DE)

(72) Inventors:
  • Miklos, Ernst
    85551 Kirchheim (DE)
  • Berghoff, Rudolf
    85716 Unterschleißheim (DE)
  • Alekseev, Alexander
    82515 Wolfratshausen (DE)
  • Rupieper, Andreas
    01328 Dresden (DE)

(74) Representative: Gellner, Bernd 
Linde GmbH Intellectual Property EMEA Dr.-Carl-von-Linde-Straße 6-14
82049 Pullach
82049 Pullach (DE)


(56) References cited: : 
EP-A1- 2 884 206
CN-A- 101 294 751
CN-Y- 201 229 083
DE-A1- 19 852 185
US-A1- 2013 118 202
CN-A- 101 294 750
CN-Y- 2 555 098
CN-Y- 201 229 084
US-A1- 2011 107 774
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The invention relates to a method and an apparatus for cooling objects with a cryogenic liquid.

    [0002] Today, nozzles are being used for quickly and gently cooling various objects such as food, metals, plastics, agricultural products etc. by means of cryogenic liquids such as liquid Nitrogen (LIN) oder liquid air (LAIR) or other cryogenic temperature fluids such as CO2, O2, CH4 etc. Such nozzles can be flat jet nozzles, single hole or multi hole nozzles, full cone nozzles, hollow cone nozzles, angled or wide angle nozzles etc.

    [0003] Also in chemistry or metallurgy and other areas cryogenic nozzles are used.

    [0004] Particularly, objects to be cooled are more or less homogeneously and evenly sprayed with the respective cryogenic liquid. For example, the document EP 2 884 206 A1 discloses cryogenic liquid cooling of objects.

    [0005] A specific characteristic of such a spraying process is the fact that the temperature difference between the cooling fluid (LIN, LAIR etc) and the object to be cooled is in the range of about 200°C which is extremely large (due to the fact that the boiling temperature of such cryogenic fluids is often lower than -180°C while the temperature of the objects to be cooled usually corresponds to the ambient (e.g. room) temperature).

    [0006] This extremely high temperature difference causes the so-called Leidenfrost effect, wherein a vapor layer is formed between the cryogenic liquid and the surface of the object or substance to be cooled (can be liquid or solid).

    [0007] This vapor layer has a heat-insulating effect and reduces a heat transfer between the cryogenic liquid and the object to be cooled. The Leidenfrost phenomenon for instance explains why a water drop moves on a hot plate instead of evaporating instantly.

    [0008] The reduced heat transfer caused by the Leidenfrost effect is bad for cooling and causes long cooling times and a less efficient use of cooling fluids.

    [0009] Based on the above, the problem to be solved by the present invention is to provide a method and an apparatus for cooling an object by means of a cryogenic liquid that allow an efficient and easy cooling of substances with a cryogenic fluid.

    [0010] This problem is solved by a method having the features of claim 1 and an apparatus having the features of claim 9. Preferred embodiments of the respective aspect of the present invention are stated in the corresponding sub claims and are described in detail below.

    [0011] According to claim 1, the method for cooling at least one object, comprises the steps of: providing at least one object to be cooled, and spatially distributing a cryogenic cooling liquid using at least one nozzle onto said at least one object so that the at least one object is cooled, particularly frozen, wherein said at least one nozzle is a fluidic oscillating nozzle, and wherein said at least one fluidic oscillating nozzle is configured to generate a spatially oscillating jet of said cryogenic cooling liquid while maintaining a constant flow rate of the cryogenic cooling liquid through the nozzle.

    [0012] Particularly, the spatial distribution of the cryogenic cooling liquid by means of the fluidic oscillating nozzle helps to reduce the negative impact of the Leidenfrost effect, since the insulating vapor barrier can be disrupted by the oscillating flow. Furthermore, using a fluidic oscillating nozzle is less difficult than generating a pulsating jet or flow of a cooling agent using a cryogenic nozzle which may alternatively be used in order to reduce the Leidenfrost effect. However, generating such pulsating jets is a relatively difficult task, since a corresponding device/mechanism is needed (e.g. a rotating nozzle rim or an ultrasound generator) which complicates the design and increases maintenance and costs.

    [0013] Preferably, the method according to the invention uses a plurality of such fluidic oscillating nozzles. Particularly, the nozzles can be equidistantly spaced with respect to one another.

    [0014] Particularly, the spatially oscillating jet of the cryogenic cooling liquid disturbs or even removes a vapor layer on the surface of the at least one object to be cooled so that the heat transfer away from the at least one object is increased.

    [0015] Of course, a plurality of objects can be cooled with the present method according to the invention, wherein objects may be cooled successively (e.g. in a tunnel freezer, see below) or all at the same time (e.g. in a cabinet freezer, see below).

    [0016] Particularly, the at least one fluidic oscillating nozzle comprises no moving parts and is configured to generate said oscillating jet by means of its geometric design, i.e., the geometric design of the involved flow paths of the nozzle. Particularly, such a fluidic nozzle is described in detail in US4955547 A (cf. e.g. Fig. 3).

    [0017] Particularly, the heat distribution in a space around the at least one object (this space can be an internal space of an enclosure such as a chamber of a cabinet freezer or a tunnel of a tunnel freezer) takes place due to evaporation of the cryogenic cooling liquid in the oscillating jet.

    [0018] Furthermore, according to an embodiment of the method according to the invention, said cryogenic cooling fluid is one of or comprises one of: liquid nitrogen (LIN), liquid air (LAIR), liquid carbon dioxide (LIC), or any other suitable cryogenic cooling liquid.

    [0019] Furthermore, according to an embodiment of the method according to the invention, said at least one object is one of: food, a plant (or a part therof), meat, seafood, fish, a beverage, an object formed out of a metal or comprising a metal, an object formed out of a synthetic material or comprising a synthetic material.

    [0020] Furthermore, according to an embodiment of the method according to the invention, the step of providing said at least one object corresponds to transporting the at least one object with a transport velocity on a conveyor through a tunnel of a tunnel freezer, which tunnel freezer comprises said at least one nozzle (or said plurality of nozzles).

    [0021] Particularly, said nozzle(s) is/are configured to discharge the cryogenic cooling liquid downwards onto the at least one object or the plurality of objects to be cooled.

    [0022] Further, according to an embodiment of the method according to the present invention, the cryogenic cooling liquid is provided upstream said at least one nozzle with an inlet pressure, wherein said inlet pressure is controlled depending on said transport velocity.

    [0023] Further, according to an embodiment of the method according to the present invention, the cryogenic cooling liquid is discharged through the at least one nozzle with a flow rate, wherein said flow rate is controlled depending on said transport velocity, particularly said flow rate is a volumetric flow rate having the SI-unit m3/s.

    [0024] In other words, having e.g. an even spatial distribution of objects on the conveyor, said inlet pressure or flow rate can be controlled depending on the throughput of the objects to be cooled through the tunnel freezer.

    [0025] Further, according to an alternative embodiment of the method according to the present invention, the step of providing said at least one object corresponds to placing the at least on object (or a plurality of objects) in a chamber, particularly a chamber of a cabinet freezer, wherein said at least one nozzle is configured to discharge the cryogenic cooling liquid into said chamber.

    [0026] When cooling objects or their surfaces in enclosures or tunnels, also the convection in the internal space defined by said enclosure or tunnel matters regarding cooling efficiency. Particularly, the better the swirling in said space, or the flow through said space (particularly circulation), the easier heat can be transported from the object to be cooled to the cold gas phase.

    [0027] Therefore, according to an embodiment of the method according to the present invention, evaporated cryogenic cooling liquid is distributed in a space adjacent said at least one object (e.g. an internal space of a tunnel freezer or of a chamber of a cabinet freezer) by means of at least one fan or a plurality of fans.

    [0028] According to yet another aspect of the present invention, an apparatus for cooling, particularly freezing, an object by means of a cryogenic cooling liquid is disclosed, which apparatus is preferably used in the method according to the present invention, and which apparatus comprises: an internal space for receiving said at least one object to be cooled, at least one nozzle that is configured to discharge said cryogenic cooling liquid into the internal space and onto the object to be cooled when the latter is arranged in said internal space, wherein according to the invention, the at least one nozzle is a fluidic oscillating nozzle (e.g. as described above).

    [0029] Particularly, the apparatus may comprise a plurality of such nozzles arranged in said internal space. Particularly, the at least one nozzle or said plurality of nozzles are arranged such in said internal space that the cryogenic cooling liquid is discharged downwards onto the at least one object or the objects to be cooled.

    [0030] According to the invention, said at least one fluidic oscillating nozzle is configured to generate a spatially oscillating jet of said cryogenic cooling liquid while maintaining a constant flow rate of the cryogenic cooling liquid through the nozzle.

    [0031] Further, particularly, the at least one nozzle is configured to provide said spatially oscillating jet of said cryogenic cooling liquid such that the heat distribution in said internal space takes place due to evaporation of the cryogenic cooling liquid in the oscillating jet.

    [0032] Particularly, according to an embodiment of the apparatus according to the present invention, said internal space is formed by a tunnel, particularly having an inlet for arranging objects to be cooled into the internal space of the tunnel and an outlet for taking cooled objects out of the internal space of the tunnel, wherein the apparatus further comprises a conveyor for transporting objects to be cooled through said internal space formed by the tunnel with a defined transport velocity (i.e. the velocity of the conveyor).

    [0033] Further, according to an embodiment of the apparatus according to the present invention, the apparatus comprises a control unit that is configured to control an inlet pressure of the cryogenic cooling liquid upstream said at least one nozzle or a flow rate of the cryogenic cooling liquid through the at least one nozzle, wherein said inlet pressure or flow rate is preferably controlled depending on said transport velocity.

    [0034] According to yet another embodiment of the apparatus, said internal space is formed by a closable chamber, e.g., here said apparatus forms a cabinet freezer.

    [0035] According to a further embodiment of the apparatus (e.g. tunnel freezer or cabinet freezer), the apparatus comprises at least one fan (or a plurality of fans) for distributing evaporated cryogenic liquid inside the internal space of the apparatus (see also above).

    [0036] Further features, advantages and embodiments of the present invention shall be described with reference to the Figure below, wherein
    Fig. 1
    shows an embodiment of an apparatus according to the present invention in the form of a tunnel freezer;
    Fig. 2
    shows a further embodiment of an apparatus according to the present invention in the form of a cabinet freezer;


    [0037] Figures 1 and 2 show embodiments of an apparatus 1 according to the present invention that is configured to cool, particularly freeze, objects O. Particularly, Fig. 1 shows an apparatus in form of a tunnel freezer 1, while Fig. 2 shows an embodiment where the apparatus 1 is formed as a cabinet freezer 1. However, the present invention is in principle applicable to all kinds of apparatus that use discharging of a cryogenic cooling liquid L for cooling or freezing objects O.

    [0038] According to Fig. 1 the apparatus 1 comprises an internal space I for receiving the objects O to be cooled, particularly to be frozen, as well as at least one nozzle 100 or a plurality of such nozzles 100, wherein the at least one nozzle 100 is a fluidic oscillating nozzle 100 that is configured to generate a spatially oscillating jet F of said cryogenic cooling liquid L while maintaining a constant flow rate of the cryogenic cooling liquid L through the nozzle 100.

    [0039] The spatially oscillating jet F of the cryogenic cooling liquid L is made to disturb or even remove a vapor layer V that normally forms on the surface of the at least one object O to be cooled so that the heat transfer away from the at least one object O is increased.

    [0040] As shown in the detail (dashed circle) of Fig. 1 and already mentioned above, the fluidic oscillating nozzle 100 preferably comprises no moving parts, but can be configured to generate said oscillating jet F by means of its geometric design. For instance, the fluidic oscillating nozzle 100 may let a central flow L of the cryogenic cooling liquid interact with two other flows L', L" so that said oscillating jet F is achieved. Alternative fluidic oscillating nozzle techniques may also be applied instead.

    [0041] Due to the oscillating jet F (or a plurality of such jets F), the heat distribution in the internal space I takes place due to evaporation of the cryogenic cooling liquid in the oscillating jet(s) F.

    [0042] As indicated in Fig. 1 the internal space I is formed by a tunnel 2 of the apparatus 1 which is designed as a tunnel freezer 1. The tunnel 2 comprises an inlet 2a for introducing objects to be cooled into the internal space I of the tunnel 2 and an outlet 2b for taking cooled objects O out of the internal space I of the tunnel 2.

    [0043] The apparatus 1 further comprises a conveyor 5 for transporting objects O to be cooled through said internal space I formed by the tunnel 2 with a transport velocity u.

    [0044] The direction D of the oscillations of the jet(s) F as indicated in the detail of Fig. 1 can be perpendicular to the direction of the velocity u, but may also be oriented parallel to said velocity u or may form some other angle with the velocity u.

    [0045] Particularly, the at least one nozzle 100 or said plurality of nozzles 100 are arranged such in said internal space I of the apparatus 1 that the cryogenic cooling liquid L is discharged downwards onto the at least one object O or the objects O to be cooled.

    [0046] Further, cryogenic cooling liquid L may be provided to the nozzle(s) 100 by a supply 8, e.g. a tank 8 that stores cryogenic cooling liquid L, which supply 8 may be connected to the nozzle(s) 100 via a valve 9.

    [0047] Further, the apparatus 1 can comprise a control unit 6 that is configured to control an inlet pressure of the cryogenic cooling liquid L upstream said nozzle(s) 100 or a flow rate of the cryogenic cooling liquid L through the nozzle(s) 100, wherein said inlet pressure or flow rate is preferably controlled depending on said transport velocity u. For this, the control unit 6 may receive said velocity u from a suitable sensor of the conveyor 5 and may cooperate with an actuator that actuates the valve 9. Alternatively, as shown in Fig. 2, the apparatus 1 may also be formed as a cabinet freezer that comprises a closable chamber 7 which forms the internal space I of the apparatus 1. Here, the objects O to be cooled are placed into the internal space I and the chamber is closed. Also here, at least one fluidic oscillating nozzle 100 or several such nozzles 100 which may be formed as shown in the detail of Fig. 1 are used to generate an oscillating jet F (or several such jets) of the cryogenic cooling liquid L that particularly disturbs or removes the vapor layer V forming around the objects O upon cooling as described before.

    [0048] Also here, the inlet pressure or flow rate of the cryogenic cooling liquid may be controlled depending on one or several parameters such as the temperature inside the internal space I etc.

    [0049] In the embodiments of Figs. 1 and 2, the cryogenic cooling liquid L may be one of liquid nitrogen (LIN), liquid air (LAIR), or liquid carbon dioxide (LIC).

    [0050] As shown in Figs. 1 and 2, the gaseous phase G of the coolant that is generated upon evaporation of the used cryogenic cooling liquid L is preferably distributed in the internal spaces I by means of at least one or a plurality of fans 4 that may be arranged in the respective internal space I.
    Reference Numerals
    1 Apparatus (e.g. tunnel freezer or cabinet freezer)
    2 Tunnel
    2a Inlet
    2b Outlet
    4 Fan
    5 Conveyor
    6 Control unit
    7 Chamber
    8 Cryogenic cooling liquid supply (e.g. tank)
    9 Valve
    100 Fluidic oscillating nozzle
    D Direction
    F Jet
    G Gaseous phase
    L, L', L" Cryogenic cooling liquid
    O Object
    V Vapor layer
    U Transport velocity



    Claims

    1. A method for cooling an object (O), comprising the steps of:

    - providing at least one object (O) to be cooled,

    - spatially distributing a cryogenic cooling liquid (L) using at least one nozzle (100) onto said at least one object (O) so that the at least one object (O) is cooled,

    characterized in that

    said at least one nozzle (100) is a fluidic oscillating nozzle (100),

    which is configured to generate a spatially oscillating flow (F) of said cryogenic cooling liquid (L) while maintaining a constant flow rate of the cryogenic cooling liquid (L) through the nozzle (100).


     
    2. The method according to claim 1, wherein said cryogenic cooling liquid (L) is one of or comprises one of:

    - liquid nitrogen (LIN),

    - liquid air (LAIR),

    - liquid carbon dioxide (LIC).


     
    3. The method according to one of the preceding claims, wherein said at least one object (O) is one of or comprises one of:

    - food,

    - a plant,

    - meat,

    - a beverage,

    - an object formed out of a metal or comprising a metal,

    - an object formed out of a synthetic material or comprising a synthetic material.


     
    4. The method according to one of the preceding claims, wherein the step of providing said at least one object (O) corresponds to transporting the at least one object (O) with a transport velocity (u) on a conveyor (5) through a tunnel (2) of a tunnel freezer (1), which tunnel freezer (1) comprises said at least one nozzle (100).
     
    5. The method according to claim 4, wherein the cryogenic cooling liquid (L) is provided upstream said at least one nozzle (100) with an inlet pressure, wherein said inlet pressure is controlled depending on said transport velocity (u).
     
    6. The method according to claim 4, wherein the cryogenic cooling liquid (L) is discharged through the at least one nozzle (100) with a flow rate, wherein said flow rate is controlled depending on said transport velocity (u).
     
    7. The method according to one of the claims 1 to 3, wherein the step of providing said at least one object (O) corresponds to placing the at least on object (O) in an internal space (I) of a closable chamber (7), particularly a chamber (7) of a cabinet freezer (1), wherein said at least one nozzle (100) is configured to discharge the cryogenic cooling liquid (L) into said internal space (I).
     
    8. The method according to one of the preceding claims, wherein evaporated cryogenic cooling liquid (G) is distributed in a space adjacent said at least one object (O) by means of at least one fan (4).
     
    9. An apparatus for cooling an object (O) by means of a cryogenic cooling liquid (L), the apparatus comprising:

    - an internal space (I) for receiving said object (O) to be cooled,

    - at least one nozzle (100) that is configured to discharge said cryogenic cooling liquid (L) into said internal space (I) and onto the object (O) to be cooled when the latter is arranged in said internal space (I),

    characterized in that
    the at least one nozzle (100) is a fluidic oscillating nozzle (100), which is configured to generate a spatially oscillating flow (F) of said cryogenic cooling liquid (L) while maintaining a constant flow rate of the cryogenic cooling liquid (L) through the nozzle.
     
    10. The apparatus according to claim 9, characterized in that said internal space (I) is formed by a tunnel (2), wherein the apparatus (1) further comprises a conveyor (5) for transporting an object (O) to be cooled through said internal space (I) with a transport velocity (u).
     
    11. The apparatus according to claim 10, characterized in that the apparatus (1) comprises a control unit (6) that is configured to control an inlet pressure of the cryogenic cooling liquid (L) upstream said at least one nozzle (100) or a flow rate of the cryogenic cooling liquid (L) through the at least one nozzle (100), wherein said inlet pressure or flow rate is controlled depending on said transport velocity (u).
     
    12. The apparatus according to claim 9, characterized in that said internal space (I) is formed by a closable chamber (7).
     
    13. The apparatus according to one of the claims 9 to 12, characterized in that the apparatus (1) comprises at least one fan (4) for distributing evaporated cryogenic liquid (G) inside the internal space (I).
     


    Ansprüche

    1. Verfahren zum Kühlen eines Gegenstands (O), umfassend die folgenden Schritte:

    - Bereitstellen mindestens eines zu kühlenden Gegenstands (O),

    - räumliches Verteilen einer kryogenen Kühlflüssigkeit (L) unter Verwendung mindestens einer Düse (100) auf den mindestens einen Gegenstand (O), sodass der mindestens eine Gegenstand (O) gekühlt wird,

    dadurch gekennzeichnet, dass

    die mindestens eine Düse (100) eine oszillierende Fluiddüse (100) ist,

    die konfiguriert ist, um eine räumlich oszillierende Strömung (F) der kryogenen Kühlflüssigkeit (L) zu erzeugen, während eine konstante Strömungsrate der kryogenen Kühlflüssigkeit (L) durch die Düse (100) aufrechterhalten wird.


     
    2. Verfahren nach Anspruch 1, wobei die kryogene Kühlflüssigkeit (L) eines der folgenden ist oder eines davon umfasst:

    - Flüssigstickstoff (LIN),

    - flüssige Luft (LAIR),

    - flüssiges Kohlendioxid (LIC).


     
    3. Verfahren nach einem der vorstehenden Ansprüche, wobei der mindestens eine Gegenstand (O) eines der folgenden ist oder eines davon umfasst:

    - Lebensmittel,

    - eine Pflanze,

    - Fleisch,

    - ein Getränk,

    - ein Gegenstand, der aus einem Metall gebildet ist oder ein Metall umfasst,

    - ein Gegenstand, der aus einem synthetischen Material gebildet ist oder ein synthetisches Material umfasst.


     
    4. Verfahren nach einem der vorstehenden Ansprüche, wobei der Schritt des Bereitstellens des mindestens einen Gegenstands (O) dem Transportieren des mindestens einen Gegenstands (O) mit einer Transportgeschwindigkeit (u) auf einem Förderer (5) durch einen Tunnel (2) eines Gefriertunnels (1) entspricht, wobei der Gefriertunnel (1) die mindestens eine Düse (100) umfasst.
     
    5. Verfahren nach Anspruch 4, wobei die kryogene Kühlflüssigkeit (L) stromaufwärts der mindestens einen Düse (100) mit einem Einlassdruck bereitgestellt wird, wobei der Einlassdruck in Abhängigkeit von der Transportgeschwindigkeit (u) gesteuert wird.
     
    6. Verfahren nach Anspruch 4, wobei die kryogene Kühlflüssigkeit (L) durch die mindestens eine Düse (100) mit einer Durchflussrate abgegeben wird, wobei die Durchflussrate in Abhängigkeit von der Transportgeschwindigkeit (u) gesteuert wird.
     
    7. Verfahren nach einem der Ansprüche 1 bis 3, wobei der Schritt des Bereitstellens des mindestens einen Gegenstands (O) dem Platzieren des mindestens einen Gegenstands (O) in einem Innenraum (I) einer verschließbaren Kammer (7), insbesondere einer Kammer (7) eines Gefrierschranks (1), entspricht, wobei die mindestens eine Düse (100) konfiguriert ist, um die kryogene Kühlflüssigkeit (L) in den Innenraum (I) abzugeben.
     
    8. Verfahren nach einem der vorstehenden Ansprüche, wobei verdampfte kryogene Kühlflüssigkeit (G) in einem Raum neben dem mindestens einen Gegenstand (O) mittels mindestens eines Ventilators (4) verteilt wird.
     
    9. Vorrichtung zum Kühlen eines Gegenstands (O) mittels einer kryogenen Kühlflüssigkeit (L), wobei die Vorrichtung umfasst:

    - einen Innenraum (I) zum Aufnehmen des zu kühlenden Gegenstands (O),

    - mindestens eine Düse (100), die konfiguriert ist, um die kryogene Kühlflüssigkeit (L) in den Innenraum (I) und auf den zu kühlenden Gegenstand (O) abzugeben, wenn letzteres in dem Innenraum (I) angeordnet ist,

    dadurch gekennzeichnet, dass
    die mindestens eine Düse (100) eine oszillierende Fluiddüse (100) ist, die konfiguriert ist, um eine räumlich oszillierende Strömung (F) der kryogenen Kühlflüssigkeit (L) zu erzeugen, während eine konstante Strömungsrate der kryogenen Kühlflüssigkeit (L) durch die Düse aufrechterhalten wird.
     
    10. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, dass der Innenraum (I) durch einen Tunnel (2) gebildet wird, wobei die Vorrichtung (1) ferner einen Förderer (5) zum Transportieren eines zu kühlenden Gegenstands (O) durch den Innenraum (I) mit einer Transportgeschwindigkeit (u) umfasst.
     
    11. Vorrichtung nach Anspruch 10, dadurch gekennzeichnet, dass die Vorrichtung (1) eine Steuereinheit (6) umfasst, die konfiguriert ist, um einen Einlassdruck der kryogenen Kühlflüssigkeit (L) stromaufwärts der mindestens einen Düse (100) oder eine Durchflussrate der kryogenen Kühlflüssigkeit (L) durch die mindestens eine Düse (100) zu steuern, wobei der Einlassdruck oder die Durchflussrate in Abhängigkeit von der Transportgeschwindigkeit (u) gesteuert wird.
     
    12. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, dass der Innenraum (I) durch eine verschließbare Kammer (7) gebildet wird.
     
    13. Vorrichtung nach einem der Ansprüche 9 bis 12, dadurch gekennzeichnet, dass die Vorrichtung (1) mindestens einen Ventilator (4) zum Verteilen verdampfter kryogener Flüssigkeit (G) innerhalb des Innenraums (I) umfasst.
     


    Revendications

    1. Procédé de refroidissement d'un objet (O), comprenant les étapes consistant à :

    - fournir au moins un objet (O) à refroidir,

    - distribuer dans l'espace un liquide de refroidissement cryogénique (L) à l'aide d'au moins une buse (100) sur ledit au moins un objet (O) de sorte que l'au moins un objet (O) soit refroidi,

    caractérisé en ce que

    ladite au moins une buse (100) est une buse oscillante fluidique (100),

    qui est configurée pour générer un flux oscillant spatialement (F) dudit liquide de refroidissement cryogénique (L) tout en maintenant un débit constant du liquide de refroidissement cryogénique (L) à travers la buse (100).


     
    2. Procédé selon la revendication 1, dans lequel ledit liquide de refroidissement cryogénique (L) est l'un ou comporte l'un parmi :

    - de l'azote liquide (LIN),

    - de l'air liquide (LAIR),

    - du dioxyde de carbone liquide (LIC).


     
    3. Procédé selon l'une des revendications précédentes, dans lequel ledit au moins un objet (O) est l'un parmi ou comprend l'un parmi :

    - des aliments,

    - une plante,

    - de la viande,

    - une boisson,

    - un objet formé d'un métal ou comprenant un métal,

    - un objet formé d'un matériau synthétique ou comprenant un matériau synthétique.


     
    4. Procédé selon l'une des revendications précédentes, dans lequel l'étape de fourniture dudit au moins un objet (O) correspond au transport dudit au moins un objet (O) avec une vitesse de transport (u) sur un convoyeur (5) par l'intermédiaire d'un tunnel (2) d'un congélateur à tunnel (1), lequel congélateur à tunnel (1) comprend ladite au moins une buse (100).
     
    5. Procédé selon la revendication 4, dans lequel le liquide de refroidissement cryogénique (L) est prévu en amont de ladite au moins une buse (100) avec une pression d'entrée, dans lequel ladite pression d'entrée est commandée en fonction de ladite vitesse de transport (u).
     
    6. Procédé selon la revendication 4, dans lequel le liquide de refroidissement cryogénique (L) est déchargé à travers l'au moins une buse (100) avec un débit, dans lequel ledit débit est commandé en fonction de ladite vitesse de transport (u).
     
    7. Procédé selon l'une des revendications 1 à 3, dans lequel l'étape de fourniture dudit au moins un objet (O) correspond à la mise en place dudit au moins un objet (O) dans un espace interne (I) d'une chambre pouvant être fermée (7), notamment une chambre (7) d'un congélateur armoire (1), dans lequel ladite au moins une buse (100) est configurée pour évacuer le liquide de refroidissement cryogénique (L) dans ledit espace interne (I).
     
    8. Procédé selon l'une des revendications précédentes, dans lequel du liquide de refroidissement cryogénique (G) évaporé est réparti dans un espace adjacent audit au moins un objet (O) au moyen d'au moins un ventilateur (4).
     
    9. Appareil pour refroidir un objet (O) au moyen d'un liquide de refroidissement cryogénique (L), l'appareil comprenant :

    - un espace interne (I) pour recevoir ledit objet (O) à refroidir,

    - au moins une buse (100) configurée pour évacuer ledit liquide de refroidissement cryogénique (L) dans ledit espace interne (I) et sur l'objet (O) à refroidir lorsque ce dernier est agencé dans ledit espace interne (I),

    caractérisé en ce que
    l'au moins une buse (100) est une buse oscillante fluidique (100), qui est configurée pour générer un écoulement oscillant spatialement (F) dudit liquide de refroidissement cryogénique (L) tout en maintenant un débit constant du liquide de refroidissement cryogénique (L) à travers la buse.
     
    10. Appareil selon la revendication 9, caractérisé en ce que ledit espace interne (I) est formé par un tunnel (2), dans lequel l'appareil (1) comprend en outre un convoyeur (5) pour transporter un objet (O) à refroidir à travers ledit espace interne (I) à une vitesse de transport (u).
     
    11. Appareil selon la revendication 10, caractérisé en ce que l'appareil (1) comporte une unité de commande (6) configurée pour commander une pression d'entrée du liquide de refroidissement cryogénique (L) en amont de ladite au moins une buse (100) ou un débit du liquide de refroidissement cryogénique (L) à travers ladite au moins une buse (100), dans lequel ladite pression ou ledit débit d'entrée est commandé en fonction de ladite vitesse de transport (u).
     
    12. Appareil selon la revendication 9, caractérisé en ce que ledit espace interne (I) est formé par une chambre pouvant être fermée (7).
     
    13. Appareil selon l'une des revendications 9 à 12, caractérisé en ce que l'appareil (1) comporte au moins un ventilateur (4) pour distribuer du liquide cryogénique évaporé (G) à l'intérieur de l'espace interne (I).
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description