DK1934537T3 - Tokammer-tørisbeholder til isoterme beholdere - Google Patents

Description

The invention relates to the field of the transportation of perishable food products in isothermal containers, where the cold chain is controlled by carbon dioxide in the solid phase ("carbon dioxide snow").

Such isothermal containers often include a cryogenic compartment positioned in the upper portion of the container, above the compartment in which are stored the products being preserved at a controlled temperature. The cryogenic compartment is materialised (using rails, an inner wall, etc.) or not, depending on the case at hand.

Conventionally, this upper compartment receives a reservoir intended to contain a coolant such as carbon dioxide in the solid phase, the sublimation of which releases cold gases, compensating for the heat entering through the seals between the container and its door or through the container's insulator.

The regulations in effect regarding compliance with the cold chain for the transport of perishable food products is known to be becoming increasingly strict, which in particular leads the major retail stakeholders to evolve in terms of the preparation and traceability of the products being transported.

However, the controlled temperature of work spaces and the holding platforms for loading conditioned containers (with food products and refrigerant), is also known to result in high energy expenditure accompanied by a low air renewal rate in all product transit spaces.

Isothermal container structures are already known, wherein the cryogenic compartment, in which the cryogenic mass is stored, is equipped with means (typically in the form of grids) designed to retain the loaded carbon dioxide snow, while allowing the gas to pass, and is designed to organise, when loading the reservoir with fluid, the action of collecting the gas from the atmosphere within the premises using an extractor. Document EP-631 096 illustrates this prior art.

More recently, document EP-823 600 proposes a container structure wherein the storage reservoir for the cryogenic mass is assembled such that it slides in horizontal slide rails of the cryogenic compartment of the container, and wherein the interior of this reservoir is divided into two areas by such carbon dioxide snow holding means, said areas comprising one carbon dioxide snow storage area, linked to liquid CO2 supply means, and one gas expansion area communicating with carbon dioxide gas suction means. The author of the document also strongly insists on the fact that the reservoir described is carbon dioxide gas-proof in order to better insulate the product preservation compartment from the cold gas products originating either from the carbon dioxide gas sublimated by the snow or from the air cooled by the radiative action of this snow.

The works successfully conducted by the Applicant have demonstrated that the containers proposed by the aforementioned document have the following disadvantages: - firstly, the fact that the reservoir is gas-proof makes the container ineffective with regard to its purpose of preserving perishable food products, as it is understood that in this configuration, the cryogenic compartment only exchanges frigories (cold) with the products through the cold horizontal wall that separates the two compartments, which is highly insufficient; - on the other hand, it is understood that the operation of this system requires specific (dedicated) containers with a suitable internal geometry (sealing surfaces, transverse grooves, etc.) additionally because the container, itself in the upper portion (ceiling), plays a role by taking part in constituting the expansion area and thus allowing for the gases to be collected. A reservoir according to the preamble of claim 1 is, for example, known in document DE-A1-19808267.

One of the purposes of this invention is therefore to propose a new carbon dioxide snow receptacle or reservoir, obviously allowing for the collection of the gases produced by the injection of liquid CO2 and their transport outside of the premises without modifying the environment, however its purpose is also to propose a reservoir that is autonomous, i.e. that can adapt to the standard version of any type whatsoever of isothermal container commercially available, the autonomy of which even enables the reservoir to be filled outside of the container and the subsequent loading of the reservoir into the container.

The works successfully conducted by the Applicant have enabled her to demonstrate that this goal could be achieved using a cryogenic reservoir, adapted to hold a cryogenic mass and to be mounted in the cryogenic compartment of an isothermal container for preserving and/or transporting perishable food products, the reservoir being equipped with connecting means for connection to a source of carbon dioxide in the liquid phase and separating means retaining the carbon dioxide snow, but letting the gas pass through, comprising: - a substantially parallelepiped carbon dioxide snow receptacle, on the one hand equipped with injecting means adapted to engage with an injector connected to a source of liquid CO2 and for injecting carbon dioxide snow into the receptacle, and on the other hand, the upper surface of which has a perforated zone for evacuating the gas generated inside the receptacle, characterised by: - a lid secured to the upper surface of the receptacle to allow a space for accumulating the generated gas between the upper surface of the receptacle and the lid; and - the presence, on one of the side surfaces of the receptacle, of said injecting means and means that on the one hand communicate with said space allowing for the accumulation of the generated gas and that on the other hand are adapted to engage with external means for evacuating the generated gases.

The reservoir according to the invention can also have one or several of the following technical characteristics: - the lid further provides a space allowing for the generated gases to pass from the receptacle to the product storage compartment, outside of the external evacuation phases for the generated gases. - the reservoir comprises a heat shield made from a heat-insulating material, preferably removable, and capable of being installed below the receptacle to protect the foods stored in the container against radiation. - the injecting means are adapted to engage with an injector equipped with a cylindrical output nozzle with a horizontal axis, extending inwards towards the receptacle, adapted to orient the injection of carbon dioxide snow substantially tangentially to a side wall of the receptacle so as to create a whirl in the receptacle.

The invention also relates to an isothermal container for preserving and/or transporting perishable food products, of the type comprising a cryogenic compartment and a product storage compartment, as well as a cryogenic reservoir, capable of being mounted in the cryogenic compartment, adapted to cool the product storage compartment, characterised in that the cryogenic reservoir is consistent with the reservoir according to this invention.

As already described hereinabove, the reservoir according to the invention can be adapted to suit all types of container and the term "cryogenic compartment" must be understood as a space conventionally located in the upper portion of the container, regardless of whether this space is materialised or not (by rails, an inner wall, etc.).

Other characteristics and advantages can be observed in the following description, which is given as a rough guide only, with reference to the appended figures, from which: - figure 1 is a partial schematic representation of a reservoir according to the invention; - figure 2 is a partial schematic representation of a reservoir according to the invention, showing a view of one of the injection modes implementing a cylindrical output nozzle with a horizontal axis, extending inwards towards the receptacle, designed to create a vortex structure; - figure 3 is a partial schematic cross-section of a container equipped with a reservoir according to the invention.

Figure 1 shows a partial schematic representation of a reservoir 1 according to the invention, comprising a substantially parallelepiped carbon dioxide snow receptacle equipped with a lid 2 and on the other hand the upper surface of which has a perforation area 3 capable of allowing for the evacuation of the gas generated inside the receptacle. Figure 1 shows a view of the perforation area in the form of a partial exploded view beneath the lid.

It also shows on the front side of the receptacle, the presence of a connecting device comprising injecting means 4 for injecting the cryogenic liquid into the receptacle, capable of engaging with external cryogenic liquid supply means (injection pistol type), and an opening 5, which is on the one hand in communication with the space located between the receptacle and the lid, said space allowing for the gases to accumulate, and which is designed to engage with the external evacuation means for the gases generated (suction means being secured to the opening 5).

The perforation area is defined so as to: - create a slight residual overpressure within the receptacle, which results in a compaction of the carbon dioxide snow produced and thus improves the density of the snow produced; - evacuate the gas, which produces a high transformation efficiency.

Figure 2 is a partial schematic representation of a reservoir according to the invention, showing a view of one of the injection modes implementing a cylindrical output nozzle 6 with a horizontal axis, extending inwards towards the receptacle, and which is designed to create a vortex structure 7. In practice, such a nozzle shape has been found to produce a snow that is stored following a geometric Vortex movement allowing for the occupation of nearly 90% of the receptacle's volume.

Figure 3 is a partial schematic cross-section of a container equipped with a reservoir according to the invention, represented with the door open so as to view the assembly of the reservoir in the upper portion of the container. A thermal barrier 8 (in this case a polyurethane foam in a plastic shell) is installed beneath the receptacle 1 to protect the chilled products that will be stored in the receptacle of the container against radiation (this can be fixed or removable in the case of the sole transport of frozen products).

The receptacle is autonomous and can be adapted to suit all types of isothermal containers. It can slide in horizontal slide rails made in the walls of the cryogenic compartment of the container, or fixed by any other means according to the needs of the end user.

As understood upon reading the description hereinabove, contrary to the prior art, the reservoir in this case is not "sealed", it allows the gases to escape: when filling via the suction system, which connects to the front surface, and under stable operation (preservation of foods) by the fact that the lid leaves a space not only above the upper surface of the receptacle (which is equipped with the grid surface), but also at the front, to allow the gas, during operation, with the door closed, to regain the product storage compartment and perform its product preservation/cooling role.

The advantages of the device according to the invention can therefore be summarised as follows: - the reservoir is autonomous and can be adapted to suit all types of isothermal containers. - it has a remarkably high carbon dioxide snow loading capacity and carbon dioxide snow loading speed, reaching up to 15 kg of snow per minute. - the "vortex"-type injecting structure and the dimensioning of the perforation area of the specific Snow / Gas separator provide excellent performance levels with regard to the transformation ratio and density of snow formed in the receptacle. - no atmospheric modification is observed in the premises implementing the container according to the invention.

Claims (5)

A cryogenic container, adapted to hold a cryogenic mass and to be mounted in the cryogenic space of an isothermal container for preserving and / or transporting perishable food products, which container is equipped with connecting means for connecting to a source of carbon dioxide in liquid phase and separating means retaining the dry ice but allowing the gas to pass, comprising: - a substantially parallelepiped-shaped receiving vessel for dry ice, which on the one hand is equipped with injection means adapted to cooperate with an injection nozzle connected to a source of liquid CO2 and allow injection of dry ice into the receiving container, and on the other hand whose upper surface which has a perforated zone for discharging the gas generated inside the container; characterized by: - a lid attached to the surface of the receiving container to form a space between the surface of the container and the lid for accumulating the generated gas; and - presence on one side of the receiving container surfaces of the injection means and means communicating on the one hand with the space for accumulation of the generated gas, and on the other hand being adapted to co-operate with external means for evacuating the generated gases. Cryogenic container according to claim 1, characterized in that the lid further forms a space which allows the generated gases to pass from the receiving container to the product storage space, outside the external evacuation phases of the generated gases. Cryogenic container according to claim 1 or 2, characterized in that it comprises a heat shield of a heat-insulating material, which can be installed under the receiving container to protect food stored in the container from radiation. Cryogenic container according to claim 1 or 2, characterized in that the injection means is adapted to cooperate with an injector equipped with a cylindrical outlet nozzle with a horizontal axis extending towards the interior of the receiving container and adapted to orient the injection of dry ice substantially tangentially. to a side wall of the receiving container to form a vortex in the container. Isothermal container for preserving and / or transporting perishable food products, of the type comprising a cryogenic compartment and a product storage compartment, as well as a cryogenic container which can be mounted in the cryogenic compartment and is adapted to cool the product storage compartment, characterized in that the cryogenic container is according to any of the preceding claims.