EP3071334A1

EP3071334A1 - Mist-diffusing head provided with a deflector

Info

Publication number: EP3071334A1
Application number: EP14821699.7A
Authority: EP
Inventors: Michel Gschwind; Julien Dubois; Abbas SABRAOUI
Original assignee: Areco Finances et Technologie ARFITEC SAS
Current assignee: Areco Finances et Technologie ARFITEC SAS
Priority date: 2013-11-19
Filing date: 2014-11-13
Publication date: 2016-09-28
Anticipated expiration: 2034-11-13
Also published as: US10980360B2; CA2931142A1; FR3013239A1; FR3013239B1; WO2015075352A1; EP3071334B1; US20160286984A1; CA2931142C

Abstract

The invention relates to a mist-diffusing head (22) for a spraying apparatus, which comprises: a mouth (15) for supplying mist to the head; an outer wall (21) having at least one mist outlet opening (24); at least one seal (26) capable of sealing the opening; and a deflector (150) connected to the wall separately from the seal and having a main surface (154) opposite the mouth with at least one portion arranged in a direction other than the direction of the mouth, a larger portion of the opening or of at least one of the openings extending opposite the deflector.

Description

Fog diffusion head with deflector

The invention relates to installations for diffusing a mist of nebulized liquid droplets onto products.

It is known from WO-2010/106276 in the name of the applicant such an installation, serving for example for a display of food products in a place of sale. The installation includes diffusers that project a mist of micro-droplets of water above the products, which preserves their freshness, improves their appearance and promotes their sale.

The installation includes a mast fed with fog and carrying a cap at the top. The plug has internal conduits coinciding with the holes of the mast to allow the diffusion of fog outside. If we turn the cap, we remove this coincidence so that the broadcast is interrupted. The cap also includes an internal baffle that changes the orientation of the fog so that it emerges from the mast with correct speed and direction.

Despite its many advantages, such a plug offers little flexibility to regulate the diffusion of fog on the products. In addition, it is relatively expensive to achieve because of its massive nature.

An object of the invention is to regulate the diffusion of the fog on the products in a more flexible way and to reduce the cost of the installation.

For this purpose, according to the invention there is provided a fog diffusion head for a nebulization installation, which comprises:

- a mouthpiece for feeding the foggy head,

an outer wall having at least one fog outlet orifice,

at least one shutter capable of closing the orifice, and

- A deflector connected to the wall independently of the shutter and having opposite the mouth a main face having at least a portion oriented in a direction other than the direction of the mouth, a larger part of the orifice or at least one of the orifices extending opposite the deflector.

Thus, thanks to the presence of the deflector, the fog jet leaves the head with an appropriate direction and speed. Indeed, the deflector reduces turbulence and recirculation inside the head and therefore the pressure losses and water losses. This largely preserves the speed of the mist passing through the head. In this way, the fog comes out with a relatively high speed, which allows the droplets to reach products. distant from the head.

In addition, the deflector being made separately from or shutters, it can easily adapt the baffle, or the orifices and the shutter or shutters, for example depending on the particularities of the installation. In particular, one can choose the shape of the baffle according to the speed and the direction of the fog jet desired. In addition, it is not necessary to equip the head of a massive piece as the plug of the aforementioned prior art. Manufacturing is simplified and its cost reduced.

Moreover, while the stopper of the aforementioned prior art requires giving the mast a particular geometry, the invention makes it possible to equip with a baffle diffusion heads of very different models. It is applicable in particular to existing heads.

Preferably, the orifice or at least one of the orifices extends integrally opposite the deflector.

This reduces the pressure losses when the fog jet out of the orifice and also reduces water losses by reducing the impact zone on the deflector.

Advantageously, the deflector has a symmetrical shape of revolution. It can be expected that it has facing the orifice or at least one of the orifices a curved profile face in a radial plane to a main axis of the deflector.

Advantageously, the profile has no inflection point.

Preferably, it has a parabolic form.

In one embodiment, the baffle has, facing the orifice or at least one of the orifices, a face with a convex profile in a plane radial to a main axis of the deflector.

In another embodiment, the profile of this face is concave.

Advantageously, the orifice or at least one of the orifices is oriented downwards. This orientation directs the fog directly to the products when they are located at a height lower than that of the head.

Advantageously, the head comprises a lid, the baffle being attached directly, and preferably rigidly, to the lid.

Preferably, the head is devoid of means for closing the mouth of supply of the head in fog.

In one embodiment, it comprises at least one fastening element extending right through the deflector along a main axis of the latter. In another embodiment, it comprises at least one fastening element extending in a blind housing of the baffle.

It can be provided that the deflector has a lower end extending above the mouth.

Thus, when liquid accumulates by condensation on the baffle, it flows through its lower end directly into the mouth, and not out of the head through the orifice or one of the orifices.

Preferably, the shutter or at least one of the shutters is movably mounted relative to the orifice being guided between the baffle and a cover of the head. Advantageously, the orifices are at least two in number and each able to put the mouth in communication with the outside of the head, the shutters being at least two in number and able to close the respective orifices, each shutter being suitable closing one of the orifices, the shutters being movably mounted relative to the wall independently of one another.

Thus, one can close or open each of the orifices independently of the other. The choice of the number of open orifices makes it possible to regulate the quantity of fog diffused on the products. And the possibility of opening one orifice rather than another makes it possible to direct the diffusion of the mist in the desired direction, for example towards certain products and not towards others. This setting can be easily changed at any time by closing some of the holes and opening others. The head therefore offers great flexibility for adjusting the intensity and orientation of the fog or jets.

Advantageously, the deflector comprises a plastic material, for example polytetrafluoroethylene.

According to the invention, a fog diffusion head is also provided for a nebulization installation, which comprises:

- a mouthpiece for feeding the foggy head,

an outer wall having at least one fog outlet orifice, the head being devoid of means for closing the orifice, and

- A deflector having opposite the mouth a main face having at least a portion oriented in a direction other than the direction of the mouth.

Advantageously, the head is devoid of means for closing the mouth of feeding the head in fog.

The invention also provides a device for diffusing a mist of droplets, which comprises at least one head according to the invention. Finally, according to the invention, there is provided a method for diffusing a mist of droplets onto products, in which at least one head according to the invention and / or at least one installation according to the invention is used.

We will now present several embodiments of the invention by way of nonlimiting examples and with reference to the appended drawings in which:

- Figures 1 to 3 are three perspective views of a display of product presentation equipped with a nebulization installation according to one embodiment of the invention;

- Figures 4 to 7 are perspective views in axial section of one of the diffusion heads of the installation of the preceding figures;

- Figures 8 to 11 are perspective views in axial section of the deflector of the head of Figures 4 to 7;

- Figures 12 to 16 are views similar to Figures 6 to 11 illustrating a second embodiment of the head;

- Figures 17 to 21 are views similar to Figures 6 to 11 illustrating a third embodiment of the head; and

- Figures 22 to 25 are elevational views of the head at the top of its mast showing the orientation of the fog or jets out of the head respectively in the absence of deflector and for the three embodiments mentioned above.

Presentation of the installation

FIGS. 1 to 11 show a food presentation installation 2. This is a piece of furniture forming in this case a table. In this example, this piece of furniture is used in a place of sale of products.

The products here are fresh products consisting of vegetables 4, 6. The invention is also used for other fresh food products such as fruit, meat or fish. It is also applicable to food products such as cheese and more generally to any product sensitive to drying, for example flowers.

The piece of furniture, which forms here a display, comprises a frame 8 and a display 10 resting on the frame and which here has a rectangular shape in plan. The display 10 comprises a bottom wall 12. The display is open at the top so that the products can be viewed or taken by the public passing around the display.

The cabinet 2 comprises means for the diffusion of a fog of droplets of nebulized water, above the products and up to them in order to preserve the freshness. For this purpose, the furniture 2 includes in particular diffusers 16, in this case two in number. They each extend in the middle part of the display, at a distance from its periphery.

The diffusers 16 are identical to each other. They are each placed at the top of a rectilinear upright vertical mast 20 with a circular cross section. They comprise a head 22 extending at the upper end of the mast. The head is closed with the exception of orifices 24. These extend for example between 0 and 1 meter above the display. In the present example, the two diffusers are separated from each other by a distance of one meter. It is advantageous that the orifices are located at height, for example at about 0.3 m from the top of the products to be moistened, ie about 0.5 m from the bottom of the display, but this depends on the proper height of the products. It is advantageous in this respect that the diffusers are adjustable in height.

The installation may also include diffusers 18 located on strips

30 which form the periphery of the display unit surrounding the wall 12 on all sides.

FIGS. 2 and 3 illustrate a part of the equipment enabling the generation of mist of water droplets and its routing to each of the diffusers. Thus, the frame 8 carries a power supply box 34 which supplies power to a fog generator 36.

The latter comprises one or more ultrasonic transmitters equipped for example with an acoustic concentration nozzle for producing the mist formed by micro-droplets of water which are then placed in suspension in an air flow. The generator is supplied with water by a suitable means. Such a generator is known in itself in particular from FR-2 788 706 and will not be described here further. It is also possible to use for this purpose a technology employing a micro-perforated membrane.

The fog thus produced comprises micro-droplets whose dimensions are between 0.2 and 50 μηη, preferably between 2 and 5 μηη. Preferably, a majority of droplets or even 95% of them have a larger dimension less than 5 μηη.

The installation comprises a set of ducts 13 by means of which the fog produced by the generator is transmitted to the diffusers 16 and 18.

The assembly is controlled by means of a housing 40 for controlling and adjusting the operation of the furniture. The housing allows in particular to adjust the ventilation speed, that is to say the speed of the air forming part of the fog, the nebulization power and other parameters of the machine (cycle, safety thresholds, etc. .). Figure 3 shows the furniture in operation, the products have been removed to better visualize the diffusion of fog. All the diffusers simultaneously diffuse jets of fogs 37, 39 through their orifices, above the wall 12 and the products. The diffusers 16 diffuse their jets 37 through their orifices 24. The fog is produced all around the diffuser 16 downwards towards the wall 12 and the products 4, 6.

We will now describe the head 22 in more detail. In the various embodiments, certain homologous elements have numerical references increased by 100.

First embodiment

This first embodiment of the head 22 is illustrated in FIGS. 4 to 11.

The head has a general shape with symmetry of revolution around the axis 19 of the mast. It comprises a body 21 formed in this case by a bowl whose wall has a section in a radial plane to the axis 19 in an arcuate shape whose center of curvature is inside the bowl. The bowl has a flared and curved shape, its diameter widening from the base of the bowl to its upper edge. This shape makes it possible to orient the orifices 24 downwards.

The bowl 21 has at its lower end a rim 23 through which it is threaded onto the upper end of the mast with the head coaxial with the mast. This rim delimits a lower entry mouth into the fog head from the mast. By mouth means a mouth formed on a lower end of the bowl 21 through which fog from the mast 20 when the head 22 is threaded onto the mast 20. This mouth 15 is clearly distinguishable on the head 22 when it is not not yet slipped on mast 20.

The bowl 21 has a circular upper opening extending in a plane perpendicular to the axis 19 and sealingly closed by a cover or removable cap 25 having a rim fitted into the opening of the bowl.

The orifices 24 have in this case an elongate shape in the vertical direction to give them a slot shape. In this example, they are identical to each other and located at the same height, being regularly distributed around the vertical axis of symmetry of the diffuser. They cross the bowl wall from inside to outside. These orifices are here six in number but this number can be varied and be for example equal to two, three, four or five or even greater than six. The axis of each orifice is inclined relative to the vertical and horizontal directions. The bowl defines an internal cavity 17 of the head. Each orifice 24 communicates the inlet mouth 15 with the outside of the head via the cavity 17, independently of the other orifices 24.

The head 22 comprises shutters 26 associated with the respective orifices 24 and the same number as these. The shutters are able to close the respective orifices, each shutter being able to close off only one of them. The shutters are identical to each other. They are mounted mobile relative to the bowl independently of each other. In this case, they are rotatably mounted relative to the bowl about the same vertical axis formed by the axis 19. The shutters 26 are not adapted to close the lower mouth 15. The head 22 is devoid of means to seal the lower mouth 15.

Each shutter 26 comprises a plug 28 extending inside the head and an operating knob 41 extending outside the head.

The lid has a lower rim having cylindrical outer and inner faces of circular section in a plane perpendicular to the axis 19. In this flange are formed circumferential through openings 32 of the same number as the shutters and receiving the latter respectively. The openings 32 are open downwards at the lower edge of the lid coming into contact with the upper edge of the bowl and each have a generally rectangular shape.

Each shutter 26 extends through one of the openings, the junction area between the plug and the button extending into the opening. The junction zone also comprises an inner guide portion 33 having a cylindrical outer face with a circular section in a plane perpendicular to the axis 19 and having the same radius as the internal face of the rim of the lid so as to make a surface contact with this last. The button 41 is also supported by its inner face against the deflector as will be seen later.

Each cap 28 has an outer face in surface contact with the inner face of the bowl and able to close the entire orifice 24 associated. This is the shutter position occupied by the shutter when it abuts against one of the circumferential ends of the aperture 32. Conversely, when it abuts against the other end of the aperture opening, the cap leaves the hole completely free. The shutter is then in the open position.

The installation works as follows. The mist generator produces a mist of nebulized water droplets suspended in a stream of air, which is conveyed upwardly in the mast 20 to the mouth 15 and then enters the cavity 17 of the head. The fog then leaves the head through the only orifices 24 whose shutters are in the open position, if there are any. The fog does not come out through the orifices whose shutters are in position shutter, if any. Knowing that the orifices are distributed around the head, it is possible to select the direction or directions in which the fog is diffused and thus the area or areas of the display that receive it. At any time, one of the buttons 41 can be operated to place the shutter in the open or closed position, independently of the other shutters. It is also possible to place all the shutters in the open position so that the fog is diffused at the same time through all the orifices 24. On the other hand, all the orifices can be closed to prevent any diffusion of the fog by the head, and for example, book this broadcast to another head of the installation.

As illustrated in FIG. 7, at least one of the shutters can also be placed in an intermediate open position of the associated orifice. In this case, this position can be any position between the total open position and the total closed position. The shutter is held there by friction. In such an intermediate opening position, the fog flow through the orifice is generally proportional to the section of the orifice which is thus left free by the shutter.

Due to the shape given to the bowl and the shutters, if condensation occurs inside the head, especially on the shutters, no flow takes place out of the head. The flow takes place entirely in the head and inside the mast.

The head 22 also comprises a deflector 150 with symmetry of revolution and disposed in the head coaxially to the bowl. The deflector has a flat disk-shaped top surface 52 and a non-planar bottom face 154 having here a concave curve profile in a plane radial to the axis 19, as shown in FIGS. 7 and 11. In the present case, this profile has a parabolic shape. The center of curvature is on the side of this face opposite the deflector itself, that is to say outside the deflector in this case. This profile has no inflection point.

The main face 154 therefore has at all points of its surface a normal oriented in a direction other than the direction of the mouth. This normal direction is generally oriented towards the wall of the bowl or to the orifices 24. Thus the entire portion of this face located opposite the mouth 15 is not oriented towards the latter. The deflector is disposed in the cavity 17 so that its upper face 52 is in surface contact with a lower face of the cover 25. It is dimensioned so that its lower face 154 then extends opposite all the orifices 24. Thus each of these orifices extends integrally opposite this face. The deflector comprises a central cylindrical duct 156 extending throughout the entire height of the deflector of the face 52 to the face 154. The deflector is fixed rigidly and directly to the cover by means of a fastener such as a screw 158 whose head in this case bears against the lower end of the deflector and whose free end enters the cover, the screw passing through the entire height of the duct 156. It is observed in particular that the deflector 150 is connected to the wall of the head and lid independently of the shutters.

The deflector has a circumferential circumferential shoulder 57 engaging its upper face 52. This shoulder cooperates with the rim of the lid located opposite and at a distance from the latter to delimit an "L" shaped section housing 35. The inner guide portion 33 of each shutter is received in this housing and has for this purpose a complementary shape profile. Thus, the shutters are movably mounted to rotate about the axis 19 by being guided by the cover and the baffle, therebetween. By this means, they are also attached to the lid and the baffle so that the cover, the shutters and the baffle can be removed in one block to access the inside of the head.

During operation of the installation, the mist enters the head through the mouth 15 and is guided by the underside 154 of the baffle and by the inner face of the bowl 21 to each of the orifices 24 which are open. The face 154 thus makes it possible to modify the orientation of the fog during its crossing of the head without reducing its speed too much and consequently its pressure.

The screw head and the lower end of the baffle extend above the mouth 15. In this way, if liquid condensation occurs on the baffle, the liquid flows by gravity into the baffle. mast 20.

In this case, the deflector is made in the form of a solid piece of plastic material, for example polytetrafluoroethylene, (for example in the materials marketed under the name "Teflon") or "Viton" by the company DuPont de Nemours ) preferred for its hydrophobic properties.

Second embodiment

We will now describe with reference to Figures 12 to 16 a second embodiment of the installation according to the invention. This installation is identical to that of the previous mode except for the shape of the deflector.

The deflector 250 differs from that of the previous mode only in two aspects. First, the lower face 254 is closer to the axis 19 than the face 154. In addition, the conduit 256 is reduced this time to a blind conduit initiating the deflector from its upper face 52 and penetrating the latter only over a fraction of its height. The member 258 used this time to rigidly attach the baffle to the lid is formed by a threaded rod penetrating into the latter.

This time it is therefore the lower tip of the deflector which constitutes the lower end and which extends above the mouth 15 to allow the flow of the condensed liquid if necessary.

The operation of the installation and the head is similar to that of the previous mode, with however an impact zone of the fog arriving from the mouth 15 on the lower face 254 reduced.

Third embodiment

Figures 17 to 21 illustrate a third embodiment of the installation according to the invention. This installation is identical to that of the previous mode except for the shape of the underside of the deflector 350.

This face 354 has this time a curved convex shape. The curved profile in an arc is thus arranged so that its center of curvature is on the same side of this face as the deflector, that is to say inside the deflector in this case.

The operation of the installation in general and the head in particular is similar to that of the previous mode, with however a fog guiding technique different from the two previous modes.

Results

FIGS. 22 to 25 show four different diffusers 22 in operation during tests. In Figure 22, the diffuser does not include a deflector in the head. Therefore, when the mist jet enters the cavity 17, it abuts against the lower flat face of the cover. In Figures 23 to 25, the head is respectively in accordance with the three embodiments which have just been presented. The plane of each of the figures intercepts the axis 19 of the mast on the one hand and the main axis of one of the orifices and the corresponding fog jet on the other hand. The test conditions are the same in all four cases. In particular, the head is fed through the mouth with an identical fog flow. In addition, apart from the presence or absence of deflector and if appropriate its shape, the head 22 is identical in all four tests.

In the case of FIG. 22, the fog jet 37 escapes from the orifice with a speed of 1.9 m / s and its direction relative to the horizontal forms an angle a of 30 °. Assuming the head is 30 cm from the droplet receiving plane, the fog spray range is 0.28 m.

In the case of Figure 23, the speed of the fog jet is this time 2.2 m / s and the angle is reduced to 22 °. The range of the fog jet is this time 0.36 m, which is consistent with the fact that the fog jet is both faster and higher. Water losses are reduced by 2% to 3% compared to the case of Figure 22.

The same values are obtained with the head of Figure 24.

Finally, with the head of Figure 25, the output speed is 1, 9 m / s, the angle of 10 ° and the theoretical range of 0.40 m. The water losses are reduced by 1% to 2% compared to the case of Figure 22.

We see that the presence of the deflector can have different effects that can accumulate. It makes it possible to raise the fog jet by reducing its inclination with respect to the horizontal direction, which causes an increase in its range, which is the case for the three embodiments of the invention. It can increase the fog outlet velocity of the head, as is the case in Figures 23 and 24.

These results come in particular from the fact that the deflector tends to reduce the turbulence of the flow of fog inside the head and contributes to make it laminar.

Increasing the speed of the jet and reducing its inclination relative to the horizontal direction cause it to be less disturbed by the possible drafts. In addition, it is possible to have the diffusers at a relatively low height where drafts are less likely to occur.

In the embodiment of Figure 24, we see that in some cases each orifice gives rise to two separate fog jets differing in different inclinations relative to the horizontal direction. This can be useful for refreshing products arranged respectively at short and long distances from the diffuser.

The invention has the advantage of being applicable to existing heads. It suffices to add to these a deflector. Similarly, depending on the circumstances of use of the same head, one can modify the fog jets it produces by replacing its deflector by a deflector of another form. Of course, we can bring to the invention many changes without departing from the scope thereof.

The installation does not necessarily form a piece of furniture. It can be used in a place of storage or production, for example a wine-making or cheese-ripening place. 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, especially on a production line or packaging. Thus, the mist of droplets can be formed from a liquid containing a biocide.

It will be possible to modify the shape, the number and the dimensions of the orifices and the shutters. Circular orifices may in particular be provided. The diffusers may be mobile and in particular rotatable about the vertical axis. The shape and dimensions of the diffusers can be changed.

The deflector to have a shape other than a symmetrical shape of revolution. Its lower face may have a non-curved profile for example comprising one or more line segments. In the presence of a curved profile, the latter may have at least one point of inflection and have a general shape of "S".

The invention is also applicable to a fog diffusion head without shutter. These include a fog diffusion head for a nebulizer installation, which includes:

- a mouthpiece for feeding the foggy head,

It can be provided that this head is devoid of means for closing the mouth of supply of the head in fog.

It will also be possible to provide an assembly comprising a fog diffusion head and at least two diffusers of different shapes that can be mounted optionally in the head, depending on the properties that it is desired to give to the fog jets escaping from the head.

Claims

claims

Fog diffusion head (22) for a nebulization installation, characterized in that it comprises:

a mouth (15) for feeding the foggy head,

an outer wall (21) having at least one fog outlet orifice (24),

at least one shutter (26) able to close the orifice, and

- a deflector (150; 250; 350) connected to the wall independently of the shutter and having opposite the mouth a main face (154; 254; 354) having at least a portion oriented in a direction other than the direction; of the mouth, a greater part of the orifice or at least one of the orifices extending opposite the baffle.

2. Head according to the preceding claim wherein the deflector has, facing the orifice or at least one of the orifices, a face (154; 254; 354) with a curved profile in a plane radial to a main axis (19 ) of the deflector, the profile being in particular devoid of inflection point and preferably having a parabolic shape.

3. Head according to at least one of the preceding claims wherein the baffle has facing the orifice or at least one of the orifices a face (354) convex profile in a radial plane to a main axis (19) of the deflector.

4. Head according to at least one of the preceding claims, in which the deflector has, facing the orifice or at least one of the orifices, a face (154; 254) with a concave profile in a radial plane at one main axis (19) of the deflector.

5. Head according to at least one of the preceding claims which comprises a lid (25), the baffle being attached directly, and preferably rigidly, to the lid.

6. Head according to at least one of the preceding claims wherein the shutter or at least one of the shutters (26) is movably mounted relative to the orifice being guided between the baffle and a cover of the head. .

7. Head according to at least one of the preceding claims wherein the orifices (24) are at least two in number and each able to put the mouthpiece in communication with the outside of the head, the shutters being at least two in number and able to close the respective orifices, each shutter being able to close one of the orifices, the shutters being mounted movable relative to the wall independently of one another.

8. Fog diffusion head for a nebulization installation, characterized in that it comprises:

- a mouthpiece for feeding the foggy head,

9. Apparatus (2) for diffusing a mist of droplets, which comprises at least one head (22) according to at least one of the preceding claims.

10. A method of diffusing a mist of droplets on products, characterized in that at least one head (22) according to at least one of claims 1 to 8 and / or at least one installation (2) is used. ) according to the preceding claim.