BLAST CHILLER EXPRESSLY FOR DOMESTIC USE

Abstract

Built-in domestic blast chiller expressly designed for domestic use. The hot components (compressor 6, condenser 7) of the blast chiller are positioned on the upper part of its rear wall (24) and in a seat (4) so as to facilitate their ventilation and in order to leave room for an inner space (33) for accomodating baking sheets, trays or grills of the same dimensions as those of traditional domestic built-in ovens.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a blast chiller expressly designed for domestic use. In fact, the blast chiller has been devised so as to work effectively in typical domestic structures where peculiar requirements are needed with respect to the industrial sector.

PRIOR ART TECHNIQUE

Blast chillers are fast cooling devices capable of rapidly reducing (about 90 minutes) the temperature of hot foods from the cooking temperature to 3° C. (blast chilling), and to the temperature of −18° C. to the core in the case of freezing thus preserving the food in the refrigerator or in the freezer. Such treatment maintains the food nutritional values while reducing bacteria proliferation. In fact, it is known that quick freezing causes the formation of micro-crystals of the water contained in foods, while slow freezing causes the formation of macro-crystals that, on the contrary, damage the molecular structure of vitamins and proteins of the same foods. Furthermore, it is obvious that the more quickly foods are frozen the more easily bacteria proliferation is prevented.

This technology is especially used in professional kitchens of restaurants and in other commercial activities such as ice-cream shops, confectionary shops, etc. Therefore blast chillers are mainly of an industrial or professional type.

The so called professional blast chillers are characterized by a rather bulky structure, similar to a cupboard provided with a lower portion for accommodating the “hot” functional components of a heat pump system topped by a compartment divided into a plurality of shelves whereon the foods to be treated are placed. It is known that such “hot” components comprise a compressor for a cooling fluid connected to a condenser. A fan is mounted in the proximity of the condenser so as to cool the same condenser. An evaporator is then mounted inside the food compartment.

It is also known that in such system the cooling fluid is compressed inside the compressor where it is overheated. Then the hot fluid goes into the condenser where it exchanges heat with the ambient air, also thanks to the fan that forces the ambient air to hit the condenser. By giving off heat the cooling fluid cools down. Subsequently, it goes through an expansion device, such as a capillary, exiting which it undergoes a quick volume expansion that causes its further cooling. The cold fluid reaches the evaporator where it exchanges heat with the air contained inside the above said food compartment. A further fan forces the air of the compartment to hit the evaporator so as the cooling down is quickened. Finally, the fluid which has absorbed the heat of the air in the compartment goes back to the compressor to start a new cycle.

In order to achieve the above said performances concerning the cooling temperature in an acceptable times, it is necessary to use compressors having great powers which might reach even 5-8 kW. As a consequence, the dimensions of the same as well as those of the corresponding components of the cooling circuit are rather bulky. However, as it regards professional use, the area where such machines are accommodated does not require particular solutions from the design point of view.

Given the above said importance from the organoleptic and health point of view of a rapid lowering of the temperature, also domestic blast chillers are becoming widely used.

Domestic blast chillers, differently from those for industrial use, have definitely more limiting requirements as far as space is concerned. In fact, kitchen furniture is standardized, especially for built-in household appliances more and more frequently used for design reasons as well.

At the same time, the performances, that is the cooling capacity in a satisfactory time, must be compared with the professional ones so as to justify a domestic use. Therefore, in the standard spaces of built-in household appliances, there must be both the above said functional compartment and the food compartment.

In order to meet these requirements, domestic built-in blast chillers of the prior art comprise a furniture unit having the same size as a conventional built-in oven. The furniture unit is divided into two compartments, a left one and a right one, wherein one of the two has usually a size greater than the other one. The smaller compartment is used to accommodate the “hot” compartment of the heat pump system, while the bigger compartment is used for the foods to be treated.

It is obvious that the above said construction forces to reduce the sizes of the grills, trays or baking sheets for the foods. In other words, it is not possible to use baking sheets of the size the same as those for ovens, but usually standard sized gastronorm baking sheets (standard EN 631) are used in blast chillers which are absolutely unsuitable for built-in ovens.

It results that producers, who are usually those who make traditional household appliances such as built-in ovens, have to invest specific resources to make trays, baking sheets or grills only for those household appliances, resulting in an evident increase of production costs.

For example, in EP1098149 there is disclosed a domestic built-in blast chiller comprising a furniture unit of basically the same size as that of a traditional built-in oven. The air circulation includes a front intake provided in the furniture unit lower edge and a front discharge provided in the upper edge of the same furniture unit, hence guiding the air to a path having two successive deviations, each one at 90° degrees.

The hot component is accommodated in a compartment which takes the whole height of the left rear corner, thus reducing the room available for the foods to be treated for the whole height of the functional compartment, as a consequence it is necessary to use custom-made grills, trays and baking sheets and that have a pentagonal perimeter, with a clear increase of production costs.

In this blast chiller the air flux sucked horizontally reaches the rear wall where it deviates by 90 degrees upwards, entering the above said compartment at the left rear corner. Then it moves up vertically, passing through the fan and then around the compressor and the condenser. When the air reaches the top part of the left compartment, it must deviate by another 90 degrees so as to reach horizontally the upper edge and exit from the front wall.

Alternatively to the above said lateral positioning of the “hot” component, the prior art envisages the condenser in the upper part or in the lower part and at the rear with respect to the food treatment compartment or box and the compressor always in the lower part and at the rear, while the “cold” component (evaporator) is usually positioned in the upper part and at a level higher than the condenser. In this configuration, the condenser, as it is lower than the evaporator, reduces, in the upper part, the depth of the refrigerating box, while the compressor reduces it in the lower part, resulting in the fact that the entire depth of the compartment is diminished. Therefore, the compartment can accommodate trays and the like having standard gastronorm sizes or smaller sizes.

It is also to note that anyway the construction is relatively complex with clear high production costs.

SUMMARY OF THE INVENTION

Object of the present invention is therefore that of providing a blast chiller expressly for domestic use capable of accommodating therein completely traditional trays, baking sheets or grills, or in other words, supports for foods of the same size as those used for built-in ovens, but, at the same time, it must ensure high performances and be simple and cost effective to make.

In order to reach such object, it is obviously impossible to keep the lateral positioning of the compressor, condenser and related fan. It is neither possible to place them in the upper or in the lower part and at the rear of the compartment for the just described reasons.

Therefore, it has been devised a different arrangement of the “hot” component, that is of the compressor and of the condenser, which would solve all the above said drawbacks and would ensure a structural simplicity and cost effectiveness.

A first object of the present invention is then a built-in domestic blast chiller comprising a blast chilling system with a refrigeration cycle, wherein the “hot” component, that is compressor, condenser and related fan, is accommodated in a specific seat outside the refrigerating box.

A second object of the invention is a blast chiller simple and cost effective to make.

A third object is a blast chiller which makes it possible to accommodate therein baking sheets, trays or grills of the same size as those for a traditional built-in oven for domestic use.

A fourth object is a blast chiller provided with the best performance of its refrigeration system.

A further object is a method for cooling the “hot” component of the refrigeration cycle of a built-in domestic blast chiller in a simple and advantageous way.

BRIEF DESCRIPTION OF FIGURES

Further characteristics and advantages of the domestic blast chiller will become more apparent from the following description of an embodiment for exemplification only but not limited to with reference to the following figures, wherein:

FIG. 1 is a schematic side sectional view of a kitchen furniture unit with a blast chiller accommodated therein, this too in a sectional view, according to the present invention;

FIG. 2 shows a rear axonometric view of the blast chiller of the invention;

FIG. 3 shows a front schematic axonometric view of the blast chiller of FIG. 2 having the food treatment compartment door open.

DETAILED DESCRIPTION OF THE INVENTION

The idea upon which the present invention is based is that of positioning in the upper part both the “hot” components, that is compressor and condenser of the refrigeration system. But it has experimentally been observed that the above said positioning causes a great number of problems mainly connected with the cooling air-flux.

In particular, after studying fluxes accurately, it has been understood how the generated air-flux interacts on the “hot” ventilated parts, condenser and compressor, when the cooling ducts are positioned at the rear in a built-in furniture unit. The study has begun by observing the motion of the incoming cooling air-fluxes in the front portion of a blast chiller of the prior art and its behaviour both upstream and downstream of the condenser.

It must also be taken into consideration that at the front, at the upper part and at the lower part, depending on the condenser position, the blast chiller has an aperture, usually finned, so as to allow the incoming of the air sucked from the outside by the fans mounted in the proximity of the condenser in order to cool the condenser itself. This air, after having cooled the condenser is blown into the rear part of the seat of the blast chiller in the furniture unit where it is built-in. In this area, there is a space in the furniture unit that allows the exit of the hot air which obviously must not be stagnant in the furniture unit itself.

In fact, the surface of the thermal exchange of the condenser is parallel to the direction of the incoming air which is sucked orthogonally with respect to the front wall of the blast chiller. This occurs because the suction fan is positioned below the condenser, therefore it, too, horizontally, that is having the rotating axis orthogonal to the surface whereon it blows the cooling air.

In this position, the sucked air must necessarily undergo a deviation by 90° in correspondence of the fan. Through experimentation measurements, it has surprisingly been observed that such deviation implies a rather relevant loss of flux, that is of pressure, probably due to the formation of turbulent flows caused by the same deviation.

The above mentioned measurements of the flux of the cooling air have brought to think that the pressure loss might affect the system efficiency. In fact, it can be hypothesized that a flux which is not optimal does not ensure an efficient cooling of the condenser, resulting in a non-optimal performance of the whole system (COP).

Now, it has been devised to try to create a flux of the cooling air which would be the most ordered possible, that is the most rectilinear possible for the whole path of the cooling air both downstream and upstream of the condenser and, of course, also in correspondence of the condenser itself.

With reference to FIG. 1, there is shown a lateral section of a piece of furniture F provided with a compartment S1 for accommodating a built-in household appliance such a traditional oven or a blast chiller for cooked foods of standard dimensions. As it can be seen, the piece of furniture can comprise, as usual, more compartments S2, S3, so as to form a column-like furniture unit F to accommodate more household appliances, kitchenware or foodstuffs depending on the necessities or preferences of usage of the furniture unit itself. Anyway, the furniture unit F is provided with a front opening O1 positioned in the lower part in the proximity of the floor (not shown), usually with a completely traditional grille (not shown), especially when the furniture unit is used for built-in fridges. At the rear of the opening, the furniture unit F defines a horizontal passage P for the ventilation air in-flux. In the proximity of the rear wall W of the furniture unit F, said passage P has an upper window O2 which allows the air to be lifted upwards, as shown by the arrows, passing into the above compartment S2. In turn, the compartment S2 has its own window O3 on the upper wall, aligned with the window O2 of the above said passage P, which directly communicates with the compartment S1. Similarly, another window O4 is provided between the compartment S1 and the above compartment S3, aligned as well with the respective windows O2 and O3. Finally, the ventilation air exits the compartment S3, and hence the furniture unit F, too, through an exit window O5 positioned in the upper wall of the furniture unit F.

In the compartment S1 there is accommodated a blast chiller 1 for fresh or cooked foods. As better shown in FIGS. 2 and 3, this blast chiller 1 is a generally box-like parallelepiped having a container 2 to reversibly close a food treatment box 3 (FIG. 3).

It is to note that in the description of the invention hereinafter terms referring to the position of any element or component of the blast chiller or of the built-in furniture unit such as upper, lower, above, below, right, left, vertical, horizontal and the like are to be understood as referring to the objects in their normal condition of use and of assembly. Therefore, also when the blast chiller is not mounted, the skilled in the art is anyhow capable of recognizing the above said references.

The container 2 comprises a front door 20 horizontally hinged so as to flap open or, according to a second configuration (not shown), the door can also be hinged vertically so as to open laterally. Above the door 20 it is provided with a series of commands C with related display to set the functions of the blast chiller 1. Furthermore, the container 2 is completed by two side walls 21, an upper wall 22, a lower wall 23, and a rear wall 24. The side 21, the upper 22 and the lower 23 walls are basically flat.

Advantageously, the rear wall 24 is shaped so as to form a seat 4 to accommodate the “hot” component of the heat pump refrigeration system of the blast chiller 1. Preferably, with reference to FIG. 1, the rear wall 24 is a portion of a casing containing the box 3 separated from the container 2. In particular, this rear wall 24 comprises a first portion 241 generally inclined downward and rearward, that is away from the door 20, and a second portion 242 substantially vertical, that is orthogonal to the lower wall 23. The casing of the box 3 is then completed by two side walls (not shown), a lower wall 31 and an upper wall 32 which joins up with said rear wall 24, as shown in FIG. 1. Practically, the rear wall 24 would constitute the rear wall of both the container 2 and the box 3. Alternatively, the side 21, upper 22, lower 23 and rear 24 walls can belong to a single casing, that is the container 2, whose inside constitutes the refrigeration box.

The seat 4, thus defined, comprises a support 5 preferably shelf-like, to support a compressor 6, a condenser 7 and cooling means 8 for the compressor and the condenser.

In particular, the support 5 is provided with apertures to allow the passage of the cooling air without any obstacles which might block its flux. On this support 5 there are fixed said cooling means 8 comprising at least a fan adapted for suction of the air from the furniture unit bottom and for forcedly pushing it directly on the condenser 7. In fact, the condenser 7 is mounted just above the fan 8 in order to be totally hit by the air just blown by the fan itself. Laterally to the fan 8/condenser 7 assembly there is the compressor 6 so that, at least in part, it, too, can be brushed by the cooling air.

It is to keep in mind that the second portion 242 of the rear wall 24 thus defines a suction guide having a smaller section which is before an expansion section in correspondence of the first portion 241. The section of the passage of the air, in correspondence of the first portion 241, is therefore larger than the section of the passage of the air obtained in correspondence of the second portion 242.

In other words, the section of the passage of the air is thus smaller upstream of the fan 8 and expanded in correspondence and downstream of the fan 8 itself. The passage of the air is therefore basically directed vertically and hits only the rear wall 24, thus obtaining the further advantage of making the thermal exchange more efficient. In fact, in the blast chiller according to the invention the upper wall 22 is not hit by the flux of the hot air as, on the contrary, it happens in the blast chillers of the prior art such as EP1098149.

Furthermore, advantageously the just described rear wall 24, and as better identified in the section of FIG. 1, cooperates with the rear wall W of the furniture unit in order to form a channel for guiding the cooling air of the “hot” component. Therefore, such geometry not only forms the seat 4 for accommodating the “hot” component but it also forms the ventilation channel of the cooling air of this same component.

In particular, as shown by the direction of the arrows of FIG. 1, the air sucked by means of the above said fan 8 from the outside through the opening O1 on the bottom of the furniture unit F, reaches the window O2, after crossing it, the air flux follows a rectilinear path just in the vicinity of the rear wall W of the furniture unit inside the compartment S2, below the accommodating compartment S1 of the blast chiller 1. Such ordered flux reaches the window O3 for entering the compartment S1 basically below the “hot” component, substantially axially aligned with the cooling fan 8 positioned just below the condenser 7. Here, the air is forced against the condenser 7 so as to hit it completely with a steady flux and without relevant pressure losses. After having passed through the condenser 7 the heated air moves up towards the communicating opening O4 between the compartment S1 and the compartment S3 above and then moves on with a rectilinear motion toward the opening O5 for exiting the furniture unit F.

From the foregoing, it is clear that the flux of the cooling air enters the lower part of the accommodating compartment S1 of the blast chiller 1 in the vicinity of the wall W of the furniture unit F, following a rectilinear and ordered motion. It is also to note that the flux when it enters the compartment S1 goes through a first channel having a smaller section defined, as previously described, by the rear wall W of the furniture unit F and by the second portion 242 of the rear wall 24 of the container 2. Subsequently, the flux expands since it meets an expansion defined by the seat 4 immediately at the base, that is upstream of the cooling fan 8 with respect to the direction of the flux of the air.

The expansion advantageously allows to increase the volume of the air that is forced against the condenser 7 by the fan 8. The result is that the more air hit the condenser and the greater the cooling capacity will be. Moreover, as the direction of the air flux is basically axial with respect to the rotation axis of the fan, the same flux is very ordered, that is without turbulences which slow down the flux speed and stagnation. Therefore there are not load losses or, in other words, loss of efficiency. In fact, the less the air remains and is stagnant in contact or in the proximity of the condenser and the more the heat is removed rapidly.

It has advantageously been devised that the flux regulation, as just described, allows the use of a refrigeration system with better performances (COP) with respect to the systems used for the built-in domestic blast chillers of the prior art. In fact, it is possible to use as refrigerant fluid R600a gas. This gas in the blast chiller of the invention works at lower pressures compared with the traditional gases used in the previously described blast chillers since it has shown a better efficiency regarding heat exchange. Consequently, it is possible to use compressors which work at lower pressures, and that is, compressors that absorb less power while operating. Furthermore, having to resist lower pressures, they are provided with more cost effective components as production costs are concerned.

Furthermore, downstream of the condenser 7, that is after the air has passed through it and thus been heated, the flux meets again a narrowing defined by the communicating opening O4 between the compartment S1 and the compartment S3 above. This causes an acceleration of the flux exiting the opening O4 upwards resulting in an easier removal of the hot air.

In EP1098149, on the contrary, the air downstream of the condenser undergoes a slowing down due to the 90 degree deviation.

Consequently, a further object of the present invention is a process for cooling the “hot” component (condenser and compressor) of a built-in domestic blast chiller, comprising the steps of:

• • providing a built-in domestic blast chiller 1 comprising a front wall 20, two side walls 21, an upper wall 22, 32, a lower wall 23, 31 and a rear wall 24, the latter provided with a first portion 241 extending from the upper wall 22, 32 towards the lower wall 23, 31 inclined away from the front wall 20 and a second portion 242 extending orthogonally to said lower wall 23, 31, said first portion 241 defines a seat 4 to receive a condenser 7, a compressor 6 and a cooling fan 8, and said second portion 242 forms, on the contrary, a suction zone of the cooling air, which zone is positioned substantially axially to said fan 8;
  • switching on the fan 8 to create an in-flux of cooling air directed rectilinearly and orthogonally to the surface of major thermal exchange of the condenser 7, travelling first a zone upstream of the fan with a flux being substantially axially aligned with said fan, and then an expansion zone in correspondence of the condenser 7.

The process preferably comprises the availability of a blast chiller as the one previously described.

Furthermore, the process can also comprise a further step of narrowing the air flux after having crossed said condenser in order to accelerate the removal of the hot air. Preferably, the rear wall of the built-in furniture unit cooperates with the wall 24 to form a suction channel having a reduced section followed by an expansion zone, as previously described.

Further, it is to note that the inner space defined by the rear wall 24 and by the other walls of the container 2, or by similar walls of the box 3, comprises a lower zone 33 (identified by the dashed line in FIG. 1) having a depth such that it allows to receive baking sheets, trays or grills having the typical dimensions of baking sheets of traditional built-in domestic ovens, that is 460 mm±20 mm width and 360 mm±20 mm depth.

In a portion above said lower zone 33, there is, instead, accommodated the “cold” component of the heat pump system, that is the evaporator 9 together with the corresponding fan 10 (FIG. 1), in a completely traditional way.

From the foregoing, it is apparent that the drawbacks related to the built-in domestic blast chillers of the prior art have been removed and, at the same time, important advantages have been reached.

In document EP1098149 the vertical portion and the inclined portion are placed side by side horizontally and not vertically aligned, that is not vertically one on top of the other as in the present invention. In other words, by that it is meant that they are vertically one on top of the other, thus forming a vertical flux along the sole rear wall 24.

Furthermore, the vertical portion of the rear wall, extending itself almost completely above the fan, does not contribute, in a significant manner, to create the flux of the cooling air. The air which is in that zone tends, on the contrary, to stagnate or to create more unwanted turbulences.

In EP 1098149 the air flux sucked horizontally reaches the rear wall where it deviates by 90 degrees upwards below the fan.

It is then apparent that the air fluxes in the expansion zone and in the eventually narrowing zone in EP 1098149 are orthogonal, while in the present invention they are rectilinear.

Document EP 1098149 hence implies a load loss as it has been described and criticised in the present description.

In fact, the maximum experimental effort has been devoted in order to optimize the positioning of the condensing system providing a suction channel of the air upstream of the condenser, followed by an expansion zone immediately below the condenser itself. It has experimentally been seen that this configuration makes it possible an optimal air flux since the air reaches the condenser in a very ordered manner, axially aligned with the cooling fan and therefore without any turbulences which cause load/efficiency losses differently from the prior art that has 90 degrees deviations of the air path. Moreover, the combination of the suction channel and of the expansion zone integrated in the built-in furniture unit allows the air exit at the necessary speed in order to reduce the temperature as much as possible. In practice the geometry of the ventilation channel and its section, that have been set after a great number of numerical analyses and laboratory tests, has made it possible to find the optimal positioning of the “hot” component in a seat of the blast chiller such that it is possible to accommodate baking sheets, without compromising the performance of the refrigeration system.

In fact, it has been discovered that such geometry allowed to reduce the dimensions of the operating components of the refrigeration system without diminishing its performances. In fact, the fluid R600a used as refrigerant has a better performance with respect to the thermal exchange and does not need great operating pressures. Consequently, the performance as regards COP is improved and the power absorbed by the compressor is reduced. All this advantageously results in lowering production costs. It is also to take into consideration that by positioning the compressor in the vicinity of the condenser, relatively long connections are not necessary therefore resulting in further reduction of components and of structural complexities.

A further advantage derives from the fact that the air suction front grilles or louvers are not any more necessary as in the case of EP1098149, besides not much appreciated by the market, resulting in the simplification and economy of the entire blast chiller structure.

A further advantage is given by the use of an ecological refrigerant fluid such as R600a type.

A great number of constructive modifications to the blast chiller of the present invention may be made by the skilled in the art without, anyway, departing from the scope of the invention as defined in the appended claims.

For example, the forms of the blast chiller walls may be modified depending on particular requirements or preferences. Anyhow, the essential characteristic of the invention is that of favouring a rectilinear and ordered air flux upstream of the fan 8. Therefore, it is a sufficient and necessary condition that from the lower wall 23 of the blast chiller a guide (or open or closed channel) extends that guides the air axially aligned with the fan 8, followed by the seat 4 to accommodate the entire “hot” component. This in order to achieve an optimal air flux and at the same time to form an inner space for baking sheets having dimensions the same as those of the traditional built-in domestic ovens.

The materials used to make the container 2 and the box 3 are usually of metal and in particular of stainless steel.

Furthermore, the box 3 may comprise an electric resistor (not shown) for cooking at low temperatures or for defrosting.

Advantageously, the blast chilling system may comprise a tray 11 to collect the mist being positioned in contact to the second portion 242 of the rear wall 24 and close to the compressor 6. It is to note that in this position the tray 11 contributes to partially guide the air flux below the fan 8 of the cooling air, thus concentrating here the greater part of the air resulting in less dissipation. Anyway, a part of the flux contacts the tray 11 and the compressor 6 so that to help the evaporation of the mist in the tray from one hand and at the same time to brush the compressor on the other hand.

A coil (not shown) may also be coupled to the tray 11 to increase the capacity of evaporation of the mist.

Claims

1. Built-in domestic blast chiller comprising a container to reversibly close a food treatment box, the container in turn comprising a front door, two side walls, an upper wall, a lower wall and a rear wall, wherein said rear wall comprises a first portion extending form the upper wall towards the lower wall inclined away from the door, and a second portion extending form said first portion orthogonally to said lower wall in a way that said first portion is on top of said second portion, said first portion forming a seat to receive a cooling fan a condenser being positioned just upon the fan, and a compressor, the first portion also forming an expansion zone for the cooling air, whereas said second portion forming a guide for suction of the cooling air, which guide is positioned substantially axially to said fan said guide for suction having a section that is smaller than the section of said seat.

2. Blast chiller according to claim 1, wherein said seat comprises a support, provided with apertures, to support the compressor, the condenser and the fan for cooling the compressor and the condenser.

3. Blast chiller according to claim 2, wherein the condenser is mounted just upon the fan in order to fully receive the air blown by the fan itself and the compressor is mounted laterally to the fan and the condenser in order to be brushed at least in part by the cooling air.

4. Blast chiller according to claim 1, wherein the rotating axis of the fan is orthogonal to the surface of major thermal exchange of the condenser and the fan is at the same time substantially axially aligned with the suction guide positioned lower to the seat in order to create an air flux substantially rectilinear.

5. Blast chiller according to claim 1, wherein the internal space defined by the rear wall comprises a lower zone having a depth adapted to receive backing sheets, trays or grills having typical dimension of the corresponding baking sheets of a built-in domestic woven.

6. Blast chiller according to claim 1, wherein the refrigerant fluid is R600a gas.

7. Blast chiller according to claim 1, comprising a tray to collect the mist, the tray being positioned in contact to the second portion of the wall rear and close to the compressor so that to contribute to partially guide the air flux below the fan, however a part of the flux contacting also the tray and the compressor so that to help the evaporation of the mist form one hand and at the same time to brush the compressor.

8. Process for cooling a condenser and a compressor of a built-in domestic blast chiller, comprising the steps of:

providing a built-in domestic blast chiller comprising a front door, two side walls, an upper wall, a lower wall and a rear wall, said rear wall being provided with a first portion extending form the upper wall towards the lower wall inclined away from the door, and a second portion extending form said first portion orthogonally to said lower wall, said first portion forming a seat to receive a condenser, a compressor and a cooling fan, and a second portion forming a suction zone of the cooling air, which zone is positioned substantially axially to said fan

switching on the fan to create an in-flux of cooling air directed rectilinearly and orthogonally to the surface of major thermal exchange of the condenser, travelling first a zone upstream of the fan with a flux being substantially axially aligned with said fan, and then arriving at an expansion zone, which zone accommodates the condenser.

9. Process according to claim 8, further comprising a step of narrowing of the air flux after having crossed said condenser in order to accelerate the removal of the hot air.