FR3028400A1 - INSTALLATION FOR REFRIGERATING PRODUCTS IN THE PRESENCE OF A LAYER OF ICE - Google Patents

Abstract

The installation (2) for cooling products comprises: - means (40) for passing a mist or a gas against a lower face of a wall having an upper surface of generally flat shape, the installation being arranged to evacuate water of the upper face, and - at least one fog diffuser (16) arranged to diffuse the mist which is passed against the lower face or a mist which comprises the gas which is passed against the lower face.

Description

The invention relates to installations for diffusing a mist of droplets of nebulized liquid onto products. The application WO 2009/053579 in the name of the Applicant discloses such an installation, serving for example for a showcase of food products 5 in a place of sale. An ultrasonic generator produces micro-droplets of water which are then transported in a stream of air to form the fog. Diffusers receive the fog and send it over the products, which preserves their freshness, improves their appearance and promotes their sale. In fact, these micro-droplets evaporate in contact with the products which they thus contribute to cooling. Because of their very small size, they do not form any wet deposits on the products. This installation forms, for example, a display of exposure to the tide radius of a store, for fish and shellfish. However, certain regulations require that this type of products be offered for sale by being kept at a particularly low temperature. Thus, in France, this temperature must be between 0 and 2 ° C for whole fish, molluscs, crustaceans cooked or raw or shells decocussed cooked or raw. This is why the aforementioned application discloses lowering the temperature of the fog and for this purpose to provide in the installation a heat exchanger that cools the fog using the freshness resulting from the ice on the display and on the screen. which are the products. The heat exchanger has a collector for collecting melt water from the ice. A duct through which the fog passes through this melt water to lower the temperature of the fog before its diffusion on the products. However this installation is likely to be improved. Indeed, it remains difficult to maintain the products at the desired temperature. In particular, the meltwater thus collected must be evacuated as often as possible or continuously, otherwise it will heat up in contact with the conduit and other elements of the installation. In return, care must be taken to keep enough water in the collector to cool the fog passing through the duct. In practice it is difficult to strike a happy medium between these antagonistic constraints. An object of the invention is to facilitate the maintenance of products at the desired temperature. For this purpose, there is provided according to the invention an installation for cooling products, comprising: means for passing a mist or a gas against a lower face of a wall having an upper face of general shape plane, the installation being arranged to evacuate water from the upper face, and - at least one fog diffuser arranged to diffuse the mist that is passed against the lower face or a mist which comprises the gas which is passed against the 5 lower face. Thus one can have on the upper face of the wall a layer of ice and on it the products to keep cool. In particular, given the generally flat shape of this face, the weight of the ice maintains a direct and close contact between the ice and the wall. Indeed, despite the fact that the ice is continually melting in contact with the wall which serves as a heat exchanger with the mist or the gas, the water is also continuously removed from this face so that the ice can remain in contact with the ice. contact with the wall. This face therefore remains constantly at the lowest possible temperature, which promotes the cooling of the mist or gas in contact with the opposite face of the wall. On the other hand, when ice is periodically added to the display as is customary, this accumulation promotes by gravity the preservation of the close contact between the ice and the wall. In addition, it is even more effective to "break" periodically accumulated ice by striking it from above, for example with a shovel, to compensate for its melting and maintain a significant contact between the ice and the wall. Thus, it maintains in contact with the wall an ice-water mixture which offers a very good contact with the wall and a pronounced cold. The invention thus makes it possible to effectively cool the fog or the gas and the products to the desired temperature without excessive energy expenditure since it is the freshness of the ice which is directly used to cool the fog or the gas. It also reduces the frequency of ice turnover on the display. Thus, this reduces the handling and the risk of musculoskeletal disorders for the personnel because of these painful and repetitive operations. On the contrary, such results are not obtained if the fog or the gas is passed through Circular ducts passing through a layer of ice. In fact, the melting occurs first in the area of the layer of ice in contact with the ducts. The melt water runs off at the bottom of the layer and gives way to a layer of air because the accumulated ice tends to form cavities and circular arches around the ducts. The ducts are no longer in contact with the ice over their entire perimeter, which affects the cooling of the fog or gas. To guard against this, an operator must very frequently intervene and break these ice cavities 35 by reconstituting a uniform layer of ice. The invention is well suited for the direct cooling of the fog, the fog being generated, then cooled against the wall and finally spread on the products. But it is also suitable for cooling a gas such as air before this gas is used to generate a fog to be subsequently diffused on products. In one embodiment, the upper face is inclined, preferably according to its longitudinal direction and / or its transverse direction.

This way, for example, can be ensured the permanent evacuation of the water appearing on the upper face. In another mode, the upper face is horizontal. Advantageously, the upper face has water holding cavities, such as cavities.

Thus, the melt water is temporarily retained on the wall and increases its contact surface with the wall. Preferably, the wall delimits an enclosure of generally flat shape. Such a shape promotes thermal exchanges between the fog and the wall. Advantageously, the wall defines an enclosure that has at least one water discharge orifice 15, preferably the enclosure having an end side and two lateral sides each having a water discharge orifice. Such an orifice makes it possible to evacuate the water that may result from condensation of the fog inside the enclosure. Thus most of the enclosure remains available to receive fog and ensure its heat exchange with the wall. Advantageously, the orifice is located in one side of the enclosure having at least one shaped section for guiding the water towards the orifice. In one embodiment, provision may be made for the wall to delimit an enclosure which has at least two internal ducts defining predetermined paths for the passage of the fog in the enclosure, the internal ducts for example being arranged in a parallel connection and preference in mutual communication. Parallel mounting allows a relatively high fog flow rate to be cooled. The fog, however, remains better cooled at low speed. Preferably, the wall delimits an enclosure which has a generally rectangular shape in plan and at least two bevels engaging one side of the enclosure opposite one side in which fog inlet and outlet ducts open. In the absence of such bevels, it is found in the corners of the rectangle the appearance of a pressure drop during the passage of fog in the enclosure. These areas can even become "dead" areas in which the fog does not circulate or very little. The presence of the bevels reduces this pressure drop by improving the circulation of the fog and therefore the heat exchanges. In one embodiment, the installation comprises an outer plate and, on the latter, a compartment comprising the wall, preferably a lower face of the compartment being equipped with a non-slip layer. Thus the invention can be implemented simply, quickly and inexpensively on an existing installation. It suffices to place the compartment on an existing tray, providing for the communication of fluid with the compartment and to cover the whole of a layer of ice. The non-slip layer keeps the compartment on the tray in place despite tilting and moisture. In another embodiment, the installation comprises a single outer plate forming the wall. This time, it is therefore expected that the wall ensuring the heat exchange between the ice 10 and the fog forms the plateau itself. The compartment is for example located under the display. Advantageously, the installation comprises a layer of anti-exudate material forming an upper face of the installation. This layer promotes the evacuation of melt water.

According to the invention there is also provided a process for cooling products in which: a mist or a gas is passed against a lower face of a wall having an upper face of generally flat shape and covered with ice, and then diffused; fog or mist which includes gas on products to be refreshed. We will now describe an embodiment of the invention and an alternative with reference to the accompanying drawings in which: - Figure 1 is a perspective view of an installation according to one embodiment of the invention, - the figures 2, 3 and 4 are perspective, top and end views of the compartment of the installation of FIG. 1 without its cover, FIG. 5 is a perspective view of the compartment cover of FIG. FIG. 6 is a partial vertical sectional view of the installation during its use, FIG. 7 is a top view of the compartment of FIG. 2 showing the fog inputs and outputs, FIG. 8 is a similar view. in Figure 7 showing an alternative embodiment, and - Figure 9 is a perspective view of the compartment showing another alternative embodiment. FIGS. 1 to 7 show in an embodiment of the invention a food product presentation installation 2. It comprises here a piece of furniture 8 forming in this case a console, a table or a display. In this example, 3028400 5- this furniture is used in a place of sale of products. The products here are fresh food products that are usually found in the tide department of stores. This is for example fish or shellfish. The furniture 8 comprises a frame 14 and a display 10 resting on the frame and which here 5 has a generally rectangular shape in plan. The display 10 comprises a flat bottom wall 12 forming an outer plate. The display unit is open at the top so that the products can be viewed or taken by the public in the vicinity of the display. The display unit for example has a length of 2 meters. Being a display of fish and crustaceans 15, it is covered with a thick layer of ice 11, visible in Figure 6, on which these products are arranged. The display is slightly inclined to better show the products. This inclination also facilitates the flow of water resulting from the gradual melting of the ice to an unillustrated collection port located in the lower part of the wall 12 for its evacuation through an ad hoc conduit. The cabinet 8 comprises means for the diffusion of a fog 37 of nebulized water droplets, above the products and up to them in order to preserve the freshness thereof. For this purpose, the furniture comprises diffusers 16, in this case four in number. They extend here each at the top of the display, near its rear edge. They are oriented to spread the fog on the display.

The diffusers 16 are identical to each other. In the present example, each diffuser is at the end of a respective rod having a shaped circular section, the diffuser having a single orifice at its free end. Naturally, other forms of diffusers are conceivable such as those presented in the documents WO 2013/034847, WO 2010/106276, FR-2,971,954, WO 2013/060970 and FR-2,995,542, all in the name of the applicant. . These diffusers each have an adjustable orientation in rotation about a horizontal axis to modify the inclination. They are also rotatably mounted relative to the frame about a vertical axis. Their position relative to the frame is adjustable in height in particular to take into account the thickness of the ice layer and therefore the position of the products in the vertical direction. It is advantageous for the orifices of the diffusers to be located at height, for example, approximately 0.3 meters from the top of the products to be moistened, ie approximately 0.5 meters from the bottom of the display, but this depends on the actual height of the products.

These settings make it possible to adjust the diffused fog flow according to the layout and the nature of the products presented. The installation may also comprise diffusers located on strips 30 which form the periphery of the display unit, surrounding on all sides the wall 12. The frame comprises equipment enabling the generation of the fog 37 of water droplets and its routing to each of the broadcasters. Thus it comprises a fog generator 34. The latter comprises one or more ultrasonic transmitters 36 equipped for example with an acoustic concentration nozzle for the production of micro-droplets of water which are then suspended in a stream of air to form the fog. Such a generator is known in itself, in particular from FR-2 788 706, and will not be described here further. The mist thus produced comprises micro-droplets whose dimensions are between 0.2 and 50 μm, preferably between 2 and 5 μm. Preferably, a majority of droplets or even 95% of them have a larger dimension of less than 5 μm. It is also possible to use droplet technology using a micro-perforated membrane. The installation comprises ducts 13 by means of which the fog produced by the generator is conveyed to the diffusers 16 from which it leaves the installation. The assembly is controlled by means of a boltier comprising automated means and for controlling and adjusting the operation of the furniture. The boltier makes it possible in particular to adjust the ventilation speed, that is to say the speed of the air forming part of the fog, the nebulizing power and other parameters of the machine (cycle, safety thresholds, etc.). We will now describe the means for cooling the fog from the generator 34 and for the diffusers 16. The installation comprises a compartment 40 delimited by two main walls 25 respectively upper 42 and lower 44. These walls are flat, parallel to each other and extend at a distance from each other to provide a space between them for the passage of fog. In particular, the upper wall 42 has an upper face 43 and a lower face 45 both flat and parallel to each other. It is the same for the lower wall 44. The compartment is also delimited by four walls which form the sides of the compartment and by two bevels. These are the upper rear 46, lower front 48 and side 50 and 52 bevels. These sides maintain the upper and lower walls at a distance from each other. The two main walls, the sides and the bevels define in the compartment a closed enclosure 54. The compartment and this enclosure each have a generally flat shape. In plan view, their general shape would be that of a rectangle if the bevels 52 that start two corners of the rectangle were absent. These bevels provide the junction between the lateral sides 50 and before 48. With the exception of the front side 48, all sides and bevels are straight here. The rear side 46 extends in a horizontal transverse direction perpendicular to the longitudinal direction corresponding to the plane of symmetry of the installation. The front side is formed by two rectilinear sections forming in this case an obtuse angle, for example of 176 °. At the junction of these two sections, a nipple 56 has an orifice communicating the outside and the inside of the compartment. The angle a is measured on the side of the enclosure and has its top at this orifice.

This arrangement, taking into account the inclination of the wall 12 and the compartment in the longitudinal direction of the wall, makes it possible to evacuate the fog condensates from the enclosure. Two similar teats 56 with respective orifices are provided at the junction of the lateral sides 50 and the respective bevels 56. Each lateral side 50 forms with the adjacent bevel 52 an obtuse angle b, for example 133 °. This arrangement makes it possible to use the same compartment in an installation which has an inclination not in its longitudinal direction but in its transverse direction. Indeed, the condensates generated inside the chamber can then be discharged on the side of the compartment by the nipple 56. Alternatively, the compartment 20 can be arranged horizontally and provide water drainage holes in the chamber. bottom wall 44. The compartment has in this case three inner walls 60, 62 extending from one to the other of the lower and upper walls. These three walls are rectilinear, extend parallel to the longitudinal direction of the display, at a distance from each other and all from the rear side 46 without reaching the bevels and the front side 48. All 25 vertical main faces. Among them there is a middle wall 60 extending along the plane of symmetry of the compartment and two side walls 62 extending midway from the medial wall 60 and one of the lateral sides 50. These walls delimit with the sides and bevels of the compartment four sections 30 64, 66 for the passage of fog. These sections have a generally sectional shape rectangular section, and are straight and parallel to each other over most of their length. The sections 64 are each delimited by a side 50 and a wall 62. The sections 66 are each delimited by a wall 62 and the medial wall 60. They each extend from the rear side 46. The wall 62 being interrupted before 35 d reaching the bevel 52, each section 64 is in communication in front of this wall with the adjacent section 66. Similarly, the sections 66 are in communication with each other at the front of the central wall 60. The compartment comprises in this case two fog inlet ducts 68 and two outlet ducts. Fog 70. These four ducts are identical to each other and each put in communication the upper rear end of a respective one of the sections with the outside of the compartment through the rear side 46. The inlet ducts 68 are here the nearest sides 50 and the outlet ducts 70 closest to the central wall 60. As illustrated in particular in Figure 1, the inlet ducts 68 are connected by ducts 13 to the fog generator 34 while the ducts The top wall 42 is formed in this case by a removable cover which allows access to the entire compartment for inspection and cleaning. The upper wall 42 also carries welded abutments 72, 74 which project from its lower face and allow this wall to fit over the rest of the compartment 40 by preventing it from slipping. They also delimit with the edge of the wall handles that facilitate its grip.

The display 12 as well as the compartment 40 is preferably made of metal, for example stainless steel. It is observed in Figure 1 that the compartment occupies only part of the upper face of the wall 12 of the display. In particular, it is not in contact with any of the lateral and longitudinal edges of this wall. It is positioned mainly in the upper half of this wall in the present example. Most of this wall remains available for ice and food products. The installation works and is used as follows. On the part of the wall 12 left free and on the cover 42 is placed a thick layer of ice 11 directly in contact therewith. On this layer, the food products are placed to be refreshed. The generator 34 produces a mist of water microdroplets placed in suspension in a stream of air. This fog is transported by the conduits 13 and the ducts 68 into the chamber 54. It thus crosses the rear upper side 46 to reach the sections 64. It travels these simultaneously and goes up through the sections 66 to exit by the ducts 70. It is observed that the ducts 13 situated upstream of the compartment with reference to the fog flow form a parallel assembly as well as the sections 64 as well as the sections 66. These are therefore two streams of fog which cross simultaneously the pregnant and independently of each other. During this crossing and given the small thickness of the chamber 35 whose width and length each exceed ten times the thickness, the fog comes into contact with the lower face 45 of the upper wall 42 on which rests directly ice. The fog is cooled as it travels through the enclosure. 3028400 - 9 - Downstream of the outlet ducts 70, it is conveyed by other conduits 13 to the diffusers 16. It leaves the installation by them for dissemination on the products 15. The compartment therefore forms a heat exchanger thermal between ice and fog. In particular, the plate 42 is sandwiched between the ice layer above and the enclosure below. This exchange causes the progressive melting of the ice. Given the inclination of the upper face of the compartment, the melt water continuously flows out of this face on the wall 12 and out of the installation. Ice 11 therefore remains in direct contact with the compartment. If, in order to compensate for the melting of the ice, it is added to the existing layer after having removed the products 15, the weight of the ice preserves a close contact between the latter and the face 43. The quantity of ice on a stall is such that that the layer has a thickness of up to 40 cm and represents 400 kg per square meter. If the fog produces condensation inside the compartment, the resulting water is removed by the nipple 56 also on the wall 12.

In the absence of bevels, there would be the appearance of two dead zones in the lower corners of the installation, the fog undergoing a loss of load. Bevels avoid this. It can be provided that the installation operates in a cycle alternating nebulization phase and stop phase. For example, one can alternate periods of 20 seconds during which fog is generated and diffused on the products and periods of 10 seconds of stopping. This shutdown period offers a sort of "breathing" phase to the products during which cold air accumulates above them. When the diffusion of the fog is resumed, this layer of air at low temperature is evacuated by being pushed by the fog that spreads over the products.

The compartment is simply placed on the plate 12. To better immobilize it, we can provide the upper face thereof with a non-slip layer. It is also possible to equip at least part of the wall 12 with an anti-exudate material which facilitates the flow of water. In another embodiment, provision may be made for the compartment to extend inside the table and for the wall 12 to form the upper wall of the compartment itself. Another variant of embodiment is illustrated in FIG. 9. This time, the upper face 43 of the upper wall 42 of the compartment, while remaining generally flat, has cavities 76 such as cavities which make it possible to retain more water. on the wall to further promote the cooling of fog or gas. The cells 76 have for example a sphere portion shape. The installation of the invention has many features and several advantages. For example, it allows the temperature of the fog to be reduced from 23 ° to 7 ° C, ie a drop of 16 ° C, maintaining such a performance for the entire duration of use of the installation, for example a day. For example, it makes it possible to pass the temperature at the heart of the products from 9 ° C. to 2 ° C., ie a decrease of 7 °. It prevents the drying of products. In particular, it maintains a certain humidity around them by an insulation effect of the fog layer. In particular, it can be seen an increase in this humidity of 5 to 10%. It further reduces the convective exchanges between the products and the ambient air and limits the heat input by radiation. Indeed, the diffusion on the products of a mist thus cooled ensures their protection and that of the ice layer with regard to the warming by the ambient infrared radiation. Indeed, a cold nebulization blanket is made. In addition, the installation protects products from ventilation that may exist in the store.

Thanks to these advantages, the installation gives a better appearance to the products on the stall. Especially the fish are brighter and look cooler. The facility increases the shelf life of the products and reduces the loss of products. This loss occurs if the condition of the products deteriorates so that they become unsaleable.

It limits the melting of ice on the surface, which reduces the need for handling to renew the layer of ice. It optimizes airflow and condensate evacuation. The invention can easily be implemented on existing stands or displays. It is easily removable, especially for cleaning.

The invention does not require prior cooling of the air used to generate the fog and can be used for this purpose use ambient air for example at 15 or 20 ° C. This is a substantial advantage because such cooling is difficult and expensive to implement. In addition, it is inefficient to output fog at low temperature.

Of course, many modifications can be made to the invention without departing from the scope thereof. In particular, the number and arrangement of the inlet and outlet ducts of the compartment may be modified. FIG. 8 illustrates an alternative arrangement of these ducts. This time, the inlet ducts 68 are disposed in the left half of the compartment when viewed in plan, the outlet ducts 70 extending in the right half. It is possible to modify the shape of the compartment and the number of passages that it spares 3028400 for the fog. The installation does not necessarily form a piece of furniture. It can be used in a place of storage or production. It can constitute a manufacturing facility and / or packaging.

The installation can also be used for disinfecting or humidifying products or volumes, for example products circulating on a carpet, in particular on a production or packaging line. The ice can be used to cool the fog without receiving products itself, the fog being diffused on products located elsewhere.

The invention is also useful for other fresh food products such as fruits, vegetables or meat. It is particularly suitable for pre-cut fruits and vegetables. It is also applicable to food products such as cheese and more generally to any product sensitive to drying, for example flowers.

The mist of droplets may be formed from a biocide-containing liquid.

Claims (12)

REVENDICATIONS1. Installation (2) for cooling products (15), characterized in that it comprises: - means (40) for passing a mist or a gas against a lower face (45) of a wall (42) having an upper face (43) of generally planar shape, the installation being arranged to discharge water from the upper face, and - at least one mist diffuser (16) arranged to diffuse the mist which is passed against the lower face or a fog that includes the gas that is passed against the underside. 10 2. Installation according to the preceding claim wherein the upper face (43) is inclined, preferably in its longitudinal direction and / or its transverse direction. 3. Installation according to claim 1 wherein the upper face is horizontal. 15 4. Installation according to at least one of the preceding claims wherein the upper face (43) has cavities (76) of water retention, such as cells. 5. Installation according to at least one of the preceding claims wherein the wall defines a chamber (54) of generally flat shape. 20 6. Installation according to at least one of the preceding claims wherein the wall defines an enclosure (54) having at least one orifice (56) for discharging water, preferably the enclosure having an end side. (48) and two lateral sides (50) each having a hole (56) for discharging water. 7. Installation according to at least one of the preceding claims, in which the wall delimits an enclosure (54) which has at least two internal ducts (64, 66) defining predetermined paths for the passage of the fog in the enclosure, the internal ducts being for example arranged in a parallel connection and preferably in mutual communication. 8. Installation according to at least one of the preceding claims, in which the wall delimits an enclosure (44) which has a generally rectangular shape in plan and at least two bevels (52) engaging one side of the enclosure opposite to one side in which the inlet ducts (68) and outlet (70) of the fog. 9. Installation according to at least one of the preceding claims which comprises an outer plate (12) and, on the latter, a compartment (40) comprising the wall (42), preferably a lower face of the compartment being equipped with a non-skid layer. 10. Installation according to at least one of claims 1 to 8 which comprises a single outer plate forming the wall. An installation according to at least one of the preceding claims which comprises a layer of an anti-exudate material forming an upper face of the plant. 12. A method for cooling products (15) in which: - a mist or a gas is passed against a lower face (45) of a wall (42) having an upper face (43) of generally planar shape and covered with ice, 10 is then diffused the fog or mist that includes the gas on products (15) to refresh.