EP1502061A1

EP1502061A1 - Non-stop water cooler

Info

Publication number: EP1502061A1
Application number: EP03752785A
Authority: EP
Inventors: Jean-Claude Fongauffier; Claude Leleu
Original assignee: Bongard SAS
Current assignee: Bongard SAS
Priority date: 2002-05-06
Filing date: 2003-05-05
Publication date: 2005-02-02
Also published as: AU2003260537A1; FR2839359A1; FR2839359B1; WO2003098138A1

Abstract

The invention concerns a water cooler operating by direct expansion on the water of the distribution system, comprising a cold producing unit (1) operating on refrigerant gas and an insulated-water cooling tank (4), the refrigerant gas circuit consisting of two parallel branches: one first branch (8) including a first coil (10) whereof the turns are arranged proximate the tank (4) wall and beneath the level of the water filling the tank, to form therein an ice bank (11); a second branch (7) including a second coil (9) offset axially outside the first (10) and whereof one of the ends is arranged at least at the proximal end of said first coil (10). The second coil (9) being lined with a coaxial coil transporting the distribution system water (13) to be cooled, the latter extending along the ice bank formed around the first coil (10).

Description

Continuous water chiller

The present invention relates to a water cooler making it possible to lower the temperature of the mains water for practically continuous operation between 0 and 3 ° C.

The cooler of the invention is used in particular in the bakery industry, an industry in which the water used for making the dough must be at the lowest possible temperature so that at the end of the kneading process, which increases obviously the temperature of the dough, it does not exceed 25 ° C.

The three elements involved in the preparation of the dough at the time of kneading are water, ambient air and flour. The latter is at the temperature of the oven, while that of the air depends in particular on climatic conditions, but is generally not lower than 18-20 ° C. In summer, this temperature can however be significantly higher, which considerably complicates the problem.

For the previous condition to be fulfilled (dough temperature less than or equal to 25 ° C), it is established that the sum of the temperatures of water, air and flour must be less than or equal to 54 ° vs. To achieve this, especially in summer when the ambient temperature is high, water, the only component on which it is possible to influence under acceptable technical conditions, must be at very low temperature.

The quantity of cold water required varies according to the size, even the type of bakery. A neighborhood bakery produces, for example, a quantity of bread and therefore dough requiring a quantity of cold water much less than the quantity required for the production of a large area. In many cases, the means for producing cold water consists of storage tanks for water cooled using a copper or stainless steel coil acting as the evaporator of the cold circuit, which is traversed by a refrigerant gas. The quantity of cold water stored depends on the importance of the production of bread, and the manufacturers of chillers therefore offer a range of tanks whose volumes are adapted to different uses.

There are also tanks that can store 1000 liters of water cooled to 0-3 ° C, for use in large areas. At the other end of the usage spectrum, suppliers also offer 90-liter vats, more particularly configured for small neighborhood bakeries.

Such a solution, in addition to being not perfect in terms of hygiene, is not very flexible, and in any case does not allow any adaptability to a unforeseen variation in production. Thus, the baker who punctually decides to increase his production will be obliged to fill a second time the tank he has, and he will therefore have to wait until the newly stored water is in turn cooled, which can take many hours. Conversely, a large area will consume the same cooling energy even if it decides to significantly reduce its production for a limited period.

To overcome this lack of flexibility, coolers have been proposed which operate to a certain extent continuously, using tanks with ice banks. These tanks are provided with a peripheral coil in which circulates a refrigerant gas which lowers the temperature of the water in its vicinity until creating a peripheral ice bank, which in turn gradually lowers the temperature of the water until 'in the center of the tank, crossed by another coil in which the water to be cooled circulates. The latter system is also not satisfactory, because after a certain number of draws of 60 liters of water (quantity normally used in bakeries to make the standard kneading dough mass according to the operating standards of industrial devices bakery), the ice has melted, and it then takes several hours to rebuild an ice bank. Typically, after six 60-liter draws, the ice is used up, and it takes about 8 hours to recreate a bench of appropriate size. However, a volume corresponding to 6 prints is notoriously insufficient, for example for large surfaces.

In this case, there is a clear break in the continuity of production of cold water, and therefore of kneading dough, a break which is also at the expense of the flexibility of use of this type of device for the production of cold water.

The invention proposes to remedy these shortcomings by proposing a cooler which offers, in the context of the operation of a bakery, both small and hypermarket, a possibility of drawing water which can be qualified. continuous.

The device of the invention is conventionally based, like its predecessors, on a refrigerating gas production group, as well as on a thermally insulated cooling tank filled with so-called cooling water. It is mainly characterized in that the refrigerant gas circuit consists of two parallel branches:

- A first branch comprising a first coil whose turns are arranged on the one hand near the wall of the tank and on the other leaves below the level of the water filling the tank, to form an ice bank; - a second branch comprising a second coil doubled by a coaxial coil conveying the network water to be cooled. Document US Pat. No. 4,754,609 describes, for example, a water cooler of a network comprising a refrigeration unit for producing refrigerant gas and a water cooling tank. The refrigerant gas circuit consists of two parallel branches, namely a first branch comprising a first coil whose turns are arranged on the one hand near the wall of the tank and on the other hand below the level of the water filling the tank to form an ice bank. A second branch has a second coil offset outside the first. In addition, the second coil is doubled by a coaxial coil conveying the network water to be cooled.

This cooler is intended to cool and dispense a drink with the addition of carbon dioxide, and is not suitable for use in food preparation units of the bakery type.

According to the invention, the second coil (9) is axially offset outside the first, with one of the ends arranged at least at the proximal end of the first coil (10), the second coil (9) extending along the ice bank (11) formed around the first coil (10).

The invention in fact proposes a first pre-cooling of the water, using the double coil, followed by a more conventional additional cooling by means of an ice bank. In the second part of the treatment using the ice bank, the water is no longer at network temperature (16-18 ° C), but it has already been cooled by the second coil and is at a temperature around 10 ° C.

As a result, the temperature exchanges in the second phase are such that the ice bank is much less stressed, and that it therefore runs out less quickly, even in the event of repeated pullings.

In reality, there are in the invention two distinct cooling means which are exerted substantially sequentially on the liquid to be cooled, and whose configuration and mutual arrangement allow performance to be optimized.

According to a possible configuration, the double coil is arranged at least partially above the level of the water filling the cooling tank.

The direct expansion carried out in the double coil is in fact not dependent on and in principle has no effect on the cooling water filling the tank. To improve the efficiency of heat exchanges, the pre-cooling is in fact carried out until the ice bank takes over the second phase of cooling. For this reason, said bench being immersed in water, the double portion of the coil has one end situated below the water level, near the end of the first coil.

Preferably, the coils are provided coaxial. The coil, which has become simple, is therefore placed equidistant from the ice bank. This configuration guarantees that the cooling of the water, at least in its second phase, takes place continuously and uniformly. The two branches of the refrigerant circuit are each controlled by a solenoid valve. Indeed, the gas circuits, for example of freon, constituting the two branches certainly operate in parallel, but must be able to be cut according to the production phase, the thickness of the ice bank, etc. according to an operating mode which will be explained in more detail below. Likewise, the network water circuit includes a flow controller which manages the flow of gas, which must for example be stopped if there is no draft, in order to prevent water from freezing in the spiral tubing.

The tank finally includes an ice bank thickness sensor, which provides information on a threshold thickness of the latter from which the circulation of the refrigerant gas must be cut in the coil that covers the ice bank. In the absence of this indication, the said bench could develop inconsiderately, or even cover the coil conveying the water to be cooled, at the risk of freezing the latter and damaging the tubing.

The tank is of course also provided with at least one means for stirring the cooling water, so as to distribute the frigories correctly, in order to achieve uniform cooling of the water. As with the geometrical configuration of the coaxial coils, this measure also aims to balance the cooling process in space, which is applied in a substantially identical manner regardless of the location of the system with symmetry of revolution of the system.

Preferably, the double coil consists of an internal coil conveying the refrigerant gas and an external coil conveying the water to be cooled. This solution is more advantageous in terms of yield. More preferably still, in the double coil, the directions of circulation of the water and the refrigerant gases are reversed.

The present invention will now be described in more detail, with reference to the appended figures, for which:

- Figure 1 is a perspective view of a cooler according to the invention;

- Figure 2 shows, in exploded perspective, the cooler of Figure 1; - Figure 3 is a block diagram of the cooler of the invention;

- Figure 4 shows, in an elevational view, the double coil performing in particular the pre-cooling of the water;

- Figure 5 shows, in elevational view, the peripheral coil forming the ice bank;

- Figure 6 shows, still in an elevational view, the fluid circuits shown respectively in Figure 4 and 5, in their nested configuration; and

- Figure 7 is a diagram showing the temperature of the water produced as a function of the number of flows requested, bearing in mind that these are limited to three per hour.

Referring to Figure 1, the cooler of the invention, of course located in a frame B, comprises a conventional cooling group (1) whose refrigerant is for example freon, which is sent in two parallel branches in particular formed separate coils (see figure

3), via control solenoid valves (2 and 3).

In the lower part, the device of the invention comprises a thermally insulated tank (4), intended to receive the cooling water in particular cooled by the ice bank (11). Figure 2 illustrates more precisely the configuration of the cooler of the invention. Most of the constituent elements of the structure of the cooler are however not directly linked to the invention, and are therefore not described in detail below. This is the case for the various components of the cooling group, which are conventional and well known in the technical field of the invention.

Referring to Figure 3, the cooling unit (1) comprises an outlet pipe (6), which is divided into two branches (7 and 8), at the inlet of which are located said solenoid valves (2 and 3). The branch (7) feeds the internal coil (9) of the double coil, while the branch (8) feeds the coil (10) constituting the ice bank (11). These two branches (7 and 8) meet in common tubing at the inlet (12) of the cooling unit (1).

The external coil (13) of the double coil is supplied by a pipe (14) connected to the water network. At the inlet of the duct (14), a flow controller (15) makes it possible to regulate or stop the circulation of gas in the coil (9), which therefore becomes a function of the circulation of water in the coil (13 ).

In fact, the controller (15) and the solenoid valves (2 and 3) make it possible to adapt the operation to the context of use of the cooler. So the situation is not not the same depending on whether you draw water or not, depending on whether there have been recent or old draws, depending on whether the ice bank is fully formed or not, etc. . In certain cases, the two branches (7, 8) of the refrigerant gas circuit operate in masked time, when it is not necessary that they are active at the same time. This is the case, for example, when the ice bank (11) is completely formed (the ice thickness probe (not shown) indicates that this bank (11) has its maximum volume): in this case, there is no there is no need to circulate the freon in the coil (10). Figure 4 shows in more detail the double coil and more particularly the refrigerant gas circuit attached to it. A filter drier (16) is arranged upstream of the solenoid valve (2) (and also of the solenoid valve (3) since it is located upstream of the separation of the branches (7 and 8)). It should be noted that the refrigerant gas circulates in the opposite direction to the direction of flow of the water.

This figure clearly shows that the double coil is in fact only half of the entire length of the geometric coil shown, which is perfectly consistent with the function of the branch (7): to pre-cool the water . In its lower part, which has become simple, the coil only carries water, which is now cooled by the water stored in the tank (4). This lower part is moreover arranged opposite the coil (10) shown in FIG. 5 fitted to the second branch (8) of the freon circuit, coil (10) which gives rise to the ice bank (11). The relative positioning of the different coils (9, 10, 13) appears in FIG. 6, which also shows their support structures (peripheral "combs"). It is the complex circuit of Figure 6 which is arranged in and above the tank (4).

Finally, Figure 7 gives an idea of the water temperature as a function of the number of draws of volumes equivalent to 60 liters of water each, considering that a maximum of 3 draws are made per hour. In this hypothesis, the water temperature does not exceed 3 ° C until around the 25 ^θ draw, that is to say after 8 hours of "continuous" consumption in the context of working a bakery .

On a theoretical level, the fact that the temperature is not kept below 3 ° C regardless of the number of draws (always assuming 3 draws of 60 liters per hour) prohibits in principle to qualify this operation as continuous . In practice, taking into account the real operating context of a bakery, being able to have for 8 hours straight the possibility of drawing three times 60 liters of water per hour leads to filling the needs of a traditional bakery: we can therefore speak of practical continuity.

The example of the cooler given above should not be considered as exhaustive of the invention, which on the contrary encompasses all the variants of shape and configuration which are within the reach of those skilled in the art.

Claims

1. Water chiller operating by direct expansion on the mains water, comprising a refrigeration unit (1) with refrigerant gas, a cooling tank (4) with thermally insulated water and a refrigerant gas circuit consisting of two branches parallels:

a first branch (8) comprising a first coil (10) whose coils are arranged on the one hand near the wall of the tank (4) and on the other hand below the level of the water filling the tank, to form an ice bank (11) there;

- a second branch (7) comprising a second coil (9) doubled by a coaxial coil conveying the network water to be cooled, characterized in that the second coil (9) is offset axially outside the first, with l 'one of the ends disposed at least at the level of the proximal end of the first coil (10), the second coil (9) extending along the ice bank (11) formed around the first coil (10).

2. Water cooler according to claim 1 or 2, characterized in that the double coil is arranged at least partially above the level of the water filling the cooling tank (4).

3. Water cooler according to any one of the preceding claims, characterized in that the coils (9, 10, 13) are coaxial.

4. Water cooler according to any one of the preceding claims, characterized in that the two branches (7, 8) of the refrigerant circuit are each controlled by a solenoid valve (2, 3).

5. Water chiller according to any one of the preceding claims, characterized in that the network water circuit comprises a flow controller (15).

6. Water cooler according to any one of the preceding claims, characterized in that the tank (4) comprises a thickness sensor of the ice bank (11).

7. Water cooler according to any one of the preceding claims, characterized in that the tank (4) is provided with at least one means for stirring the cooling water.

8. Water cooler according to any one of the preceding claims, characterized in that the double coil (9, 13) consists of a coil internal (9) conveying the refrigerant gas and an external coil (13) conveying the water to be cooled.

9. Water cooler according to the preceding claim, characterized in that, in the double coil (9, 13), the directions of circulation of the water and the refrigerant gases are reversed.