EP0157061A1 - Refrigeration machine for cooling cylindrical articles or cylindrical packages containing liquids - Google Patents

Abstract

The machine comprises, in the direction of displacement of the refrigeration fluid, a compressor (2), a condenser (3), an expander (4) and an evaporator (1) and is characterised in that said evaporator (1) is constituted by an enclosure formed by a double wall (1a/1b) which is sealed around its circumference (1c/1d/1e/1f), which enclosure adopts the general form of a cylinder which is open at its ends (1c/1d) and over the height of the enclosure (1e/1f) and the internal diameter of which is essentially equal to that of said article or of said package, with which the enclosure is in contact during the refrigeration phase. <IMAGE>

Description

The present invention relates to a refrigeration device for unit cooling of cylindrical objects or cylindrical packages containing liquids.

The technical sector of the invention is that of equipment falling within the framework of the refrigeration industry.

It is already known to use helical evaporators in order to obtain the cooling of beer cans in particular, in the empty core of which the bottle to be cooled is introduced.

For a good transfer of frigories, we know that good contact is necessary between the bottle and the evaporator coil, which supposes a rigorous correspondence of the ribs of the parts in contact.

This requirement therefore excludes containers whose lateral surface has reliefs, for example engravings, for bottles or crimp beads for boxes or barrels.

The transmission of cold in known devices is also made in poor conditions since the exchange surfaces are necessarily reduced to the contact that may exist between the coil and the container, which for the most part results in a simple generator of the propeller.

The present invention aims to remedy this drawback.

The objective to be achieved is a refrigerating apparatus comprising an evaporator allowing the introduction of the container to be cooled not only by its ends but also laterally, which makes it possible for example to cool bottles comprising reliefs (mention of capacity, trade mark. ..) or crimped bottom boxes.

This objective is achieved by the refrigerating apparatus according to the invention for cooling cylindrical objects or cylindrical packages containing liquids and comprising in the direction of movement of the refrigerating fluid: a compressor, a condenser, a pressure reducer and an evaporator, characterized in that said evaporator is constituted by an enclosure formed by a tight double wall around its periphery, which enclosure adopts the general shape of a cylinder open at its ends and over the height of the enclosure and whose internal diameter is substantially equal to that of said object or said packaging on which the enclosure is in contact during the refrigeration phase.

In one embodiment, the enclosure is of a cross section at least semi-circular.

In another embodiment, the evaporator comprises a network of pipes in loops occupying almost the entire surface of the evaporator and in which network circulates the refrigerating fluid. Preferably said pipes are of a flattened cross section.

In such an evaporator, the internal face of the enclosure is smooth so as to be tightly pressed against the object or the cylindrical package to be cooled.

In one embodiment of the device, the suction duct and the tubing coming from the regulator open into the double wall of the enclosure or into pipes of said network and in the vicinity of one of the two edges which delimit its lateral opening, to allow free elastic deformation of the evaporator.

The result of the invention is a refrigeration device allowing the unitary cooling of cylindrical objects or cylindrical containers containing liquids such as for example drinks.

The evaporator which equips said device offers the particularity of being self-tightening, that is to say of applying its internal face against the wall of the container or of the object to be cooled.

This self-tightening is based on the principle of the elastic deformation of a metallic hollow body subjected to a pressure variation of a fluid. This principle is already applied in many devices such as the so-called "Bourdon tube" pressuremeters comprising a curved tube, the open inlet end of which is fixed and the opposite closed end acts mechanically on a movable member (needle, breaker, etc.). ) when the tube deforms under the effect of the fluid pressure.

According to the present invention, it is no longer a tube but a flat enclosure obtained by concentric winding of two plates of equal height; the outer plate will be longer by the difference: A L = A D x 3.14, compared to the inner plate, A D being the difference between the average diameters of the two assembled plates and Q the portion of total circumference occupied by the assembly.

If a pressure P is applied between the two assembled plates, the external force Pl = P x S outside being greater than the force P2 = P x S inside, the resulting force PR = P x Δ S will be exerted towards the outside and will tend to unroll the whole, drawing aside the extreme edges of the assembly. A decrease in pressure will tend to the reverse maneuver, that is to say decrease the volume delimited by the inner plate.

It is this effect that the invention proposes to use to obtain self-tightening of the container by the evaporator.

• - la figure 1 est une coupe transversale d'un évaporateur équipant un appareil selon l'invention;
• - la figure 2 est une vue en perspective schématique d'un appareil selon l'invention et dans un mode d'exécution;
• - les figures 3 et 4 sont des vues en coupe schématique illustrant le fonctionnement de l'évaporateur;
• - la figure 5 est une vue de dessus développée d'un évaporateur comportant un réseau de canalisations en boucles;
• - la figure 6 est une vue en perspective schématique d'un appareil selon l'invention équipé d'un évaporateur selon la figure 5;
• - la figure 7 est une vue en coupe de l'évaporateur suivant la ligne VII VII de la figure 5.

The characteristics and other advantages of the invention will become apparent on reading the following description of various embodiments of an apparatus and its evaporator with reference to the appended drawing in which:

• - Figure 1 is a cross section of an evaporator fitted to an apparatus according to the invention;
• - Figure 2 is a schematic perspective view of an apparatus according to the invention and in one embodiment;
• - Figures 3 and 4 are schematic sectional views illustrating the operation of the evaporator;
• - Figure 5 is a top view developed of an evaporator comprising a network of looped pipes;
• - Figure 6 is a schematic perspective view of an apparatus according to the invention equipped with an evaporator according to Figure 5;
• - Figure 7 is a sectional view of the evaporator along line VII VII of Figure 5.

Reference is first made to FIGS. 1 and 2 of the drawing which illustrate an apparatus and an evaporator according to the invention in one embodiment.

The refrigeration apparatus according to the invention comprises an evaporator of a generally cylindrical shape 1 for closely surrounding a cylindrical object, a compressor 2, a condenser 3 for example of the ventilated type and a pressure reducer 4, for example a capillary helical coil.

Said evaporator 1 consists of two curved plates la / lb, for example of aluminum alloy, which plates are curved along radii Rl / R2, are parallel to each other and are joined at their upper, lower and lateral ends 1c / 1d / 1e / 1f where they are joined by hot rolling or by welding.

Said evaporator thus forms a double wall which delimits an enclosure in which the refrigerant circulates.

As illustrated in the drawing, the evaporator adopts the general shape of a horseshoe and is open at its upper and lower ends and also on part of its lateral wall, the lateral opening being thus delimited by the edges the / If of the double wall. According to this design, the evaporator 1 can be provided with a more or less wide opening as shown in FIGS. 1, 3 and 4. So that the objects to be cooled can be introduced laterally (FIGS. 3 & 4), it can be formed of a double wall covering the surface of a half-cylinder.

In another embodiment, and to obtain cooling under better conditions, the double wall can cover almost all of a cylinder. The figure illustrates an evaporator which covers approximately three-quarters of a cylinder.

The peculiarity of such an exchanger is that the two edges le / If which delimit the lateral opening can move away or come closer under the effect of the cooling fluid which, as has been previously exposed, being at a pressure P , exerts on the internal walls of the enclosure, force pressures Pl / P2 such that their resultant PR tends to "open" the evaporator as illustrated in FIG. 3 and for the reasons which will be explained below.

According to the example of FIG. 2, the duct 5 is connected on the one hand to the pressure reducer 4, which is according to this example a capillary, and on the other hand to the upper part of the evaporator 1, for example at the top and on the edge side. The compressor 2 is connected by the conduit 6 to the upper part of the evaporator, this conduit terminating in the vicinity of the edge If. The duct 6 is connected to the suction of the compressor 2. The cooling fluid discharged by the compressor is sent through the pipe 7 into the condenser 3 and is circulated first in the regulator 4 and then in the evaporator 1 by being admitted into the latter by the tube 5. The fluid admitted into the double wall la / lb scans the enclosure as is represented by the arrows FI / F2.

The oil entrained by the fluid is collected at the lower part of the exchanger and is evacuated by a tube 8 which connects the lower part of the enclosure and the compressor 2. This tube 8 is of very small section to avoid the fluid entrainment refrigerant. For example, this tubing 8 is located on the side of the edge 1f of the evaporator, below the pipe 6 and is connected to the latter.

In another embodiment, the evaporator although of a design similar to that which has just been described comprises (FIGS. 5 and 7) a network of pipes in loops.

In this design (FIG. 7) the internal wall 1b is smooth to favor the exchange in contact with the object to be cooled while the external wall 1a is corrugated to form pipes 1g of a flattened cross section.

The circulation of the cooling fluid in an evaporator of this type is illustrated in FIG. 5 of the drawing. The pipes 1g extend in the direction of the length of the evaporator, which is shown flat. The pipes lg are thus parallel to one another and are connected to each other by forming loops. The fluid is admitted to the upper part of the evaporator and is sucked in at its lower part by circulating in the direction of the arrows. In this way, the fluid concerns the entire surface of the evaporator.

An apparatus comprising an evaporator of this type is illustrated in FIG. 6 of the drawing, the parts 2, 3, 4 and 7 of which are identical to those of FIG. 2 previously described.

The refrigerant is admitted through the pipe 5, which is connected to a pipe lj which opens into the upper part of the extreme high pipe lg. The outlet of the fluid is carried out by a conduit lh having the same section as the conduit Ij, which conduit lh opens out at the bottom of the extreme low line Ig.

In one embodiment and for technological considerations, the fluid suction pipe lh extends over part of the height of the enclosure and is brought below and in the vicinity of the delivery pipe. entry lj.

The duct 1h is connected to the compressor by means of a stopper 9.

It can be seen in FIG. 6 that, in the device which is illustrated, the evaporator can deform freely due to the fact that the two pipes 5 and 9 are situated on the same side and in the vicinity of the edge 1a of the evaporator, the other edge If thus being freed from all mechanical stress.

The evaporator according to Figures 5, 6 and 7 is for example produced by the hot rolling and inflation process of the refrigeration circuit, known as "Rollbond".

The pressure in the evaporator being that of the low pressure branch (outlet of the expansion valve-evaporator-suction of the compressor) and variable depending on the refrigerant used and the conditions of use, is less than or at most, equal to half the pressure prevailing in the high pressure branch (compressor discharge, condenser, regulator inlet), when the system is operating normally. When the compressor stops, this low pressure is equalized with the high pressure, at an average pressure HP - BP + BP.

2

• Exemples : A P pour Freon 12 1,5 bar
• A P pour Freon 22 3 bars

It therefore appears that between the pressures prevailing in the evaporator when stopped and in operation, there is a significant difference.

• Examples: AP for Freon 12 1.5 bar
• AP for Freon 22 3 bars

When stopped, the evaporator undergoing greater internal pressure will tend to unwind, making it possible to place the object to be cooled in its center 10. As soon as the refrigeration system starts, the pressure falling in the evaporator will close on the object, ensuring a satisfactory thermal connection, and a good performance of the device.

• K = 4,18 λ où K est le coefficient global de conductibilité e thermique exprimé en kilojoules par kilogramme kelvin par degré centigrade, où e est la distance séparant les surfaces d'échange, exprimée en mètres, et À le coefficient spécifique de conductibilité thermique du corps séparant les surfaces d'échange.

This is demonstrated by the formula:

• K = 4.18 λ where K is the overall coefficient of thermal conductivity e expressed in kilojoules per kilogram kelvin per degree centigrade, where e is the distance separating the exchange surfaces, expressed in meters, and À the specific coefficient of thermal conductivity of the body separating the exchange surfaces.

In the ratio of K, K is proportional to À, and inversely proportional to the distance e.

To increase K, it is therefore necessary to decrease "e" by a good tightening of the evaporator on the object.

The most interesting application is the cooling of cylindrical objects, part of an evaporator rolled to its exact size (small beer kegs, bottles, cylindrical cans, etc.) which must be quickly cooled over their entire outer surface. to avoid thermal stratification of the liquid (hot at the top, cold at the bottom), in a space-saving device; the replacement of the empty container 10 being carried out when the the device.

A change of a few millimeters in the circumference formed by the evaporator is sufficient to tighten or release the object 10. This system applies validly for the refrigeration of any object of cylindrical or approaching section, comprising a continuous curve over at least half of its perimeter, allowing lateral or extremity introduction into the evaporator.

Alternatively, the evaporator I may include one or more toggle closure devices or the like, for manually obtaining the application of the internal wall 1b of the enclosure against the cylindrical objects or containers to be cooled, which locking device is fixed at the double wall, in the vicinity of each of the lateral edges le / lf of the evaporator.

Claims (13)

1. Refrigerating apparatus for cooling cylindrical objects or cylindrical packages containing liquids (10) and comprising, in the direction of movement of the refrigerating fluid: a compressor (2), a condenser (3), a pressure reducer (4) and an evaporator (1), characterized in that said evaporator (1) consists of an enclosure formed by a double wall (1a / 1b) sealed around its periphery (Ic, Id, le, If), which enclosure adopts the general shape a cylinder open at its ends (1c / 1d) and over the height of the enclosure (le / If) and whose internal diameter is substantially equal to that of said object or of said packaging (10) on which the enclosure is on contact during the refrigeration phase. 2. Apparatus according to claim 1, characterized in that the evaporator (1) is of a cross section at least semi-circular. 3. Apparatus according to any one of claims 1 or 2, characterized in that the evaporator (1) comprises a network of pipes in loops (1g) occupying almost the entire surface of the evaporator (1) and in which network circulates the refrigerant. 4. Apparatus according to claim 3, characterized in that said pipes (Ig) are of a flattened cross section. 5. Apparatus according to any one of claims 3 or 4, characterized in that the internal face (Ib) of the evaporator (1) is smooth to be tightly pressed against the object or the cylindrical packaging (10) to cool. 6. Apparatus according to any one of claims 1 to 5, characterized in that the suction duct (6) and the pipe (5) coming from the holder (4) open into the double wall of the enclosure or into pipes (lg) of said network and in the vicinity of one of the two edges (le / If) which delimit its lateral opening to allow free elastic deformation of the evaporator (1). 7. Apparatus according to any one of claims 1 or 2, characterized in that the suction duct (6), which connects the evaporator (1) to the compressor (2) terminates in the upper part and in the vicinity of the 'one of the two edges (If) which delimit its lateral opening and the conduit (5) which connects the evaporator (1) to the pressure reducer (4) opens at the top and in the vicinity of the other edge (le) which delimits said lateral opening. 8. Apparatus according to any one of claims 1, 2 or 7, characterized in that it further comprises a pipe (8) returning to the compressor (2) the oil entrained by the refrigerant, which pipe (8) opens into the double wall of the enclosure in part below and below the suction pipe (6) which connects the evaporator (1) to the compressor. 9. Apparatus according to any one of claims 1 to 5, characterized in that the duct (5) which connects the evaporator to the regulator (4) opens into the extreme upper pipe (lg) of the network of the enclosure and that the suction duct (6) which connects the evaporator (1) to the compressor (2) opens into the lower extreme pipe (1g) of said network. 10. Evaporator for a refrigeration installation, which is connected on the one hand to a compressor (2) and on the other hand to a condenser (3), characterized in that it is constituted by an enclosure formed by a double wall ( la / lb) tight around its periphery (1c / 1d / 1e / 1f) in which circulates a refrigerating fluid, which enclosure adopts the general shape of a cylinder open at its ends (1c / 1d) and over the height of the pregnant (le / If). He. Evaporator according to claim 10, characterized in that the enclosure comprises a network of pipes (1g) in loops which occupies almost the entire surface of the enclosure and in which network circulates a refrigerating fluid. 12. Evaporator according to claim 11, characterized in that said pipes (lg) are of a flattened cross section. 13. Evaporator according to any one of claims 11 and 12, characterized in that the internal face (1b) of the enclosure is smooth and in that said pipes (Ig) form reliefs on the external face of the enclosure .

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