EP1053440B1 - Snow, ice particle generator, or nucleation device, integrated in a pressurised water spray head for making artificial snow - Google Patents

Abstract

A nucleation device associated with a spray head and operating by either internal mixing or external mixing. The ratio air/water is not less than 200 and the pressurized water is supplied by the spray head nozzles, which, by simple circulation of water, at the nucleation device, prevents freezing problems. The nucleation device includes a part in the shape of a spray tip for high speed spraying of compressed air and parts in the shape small diameter nozzles for spraying pressurized water into the air stream.

Description

The present invention relates to an ice particle generator or of snow, also called nucleation device or nucleator, integrated in a pressurized water spray head for making snow culture, according to the preamble of claim 1. Such a device is known for example from document US-A-4,593,854.

These nucleation devices are practically essential when the production of artificial snow is carried out by means of simple spraying water, in order to carry out seeding and production fast snow i.e. even under temperature limit conditions and humidity.

Nucleation devices, or nucleators, are devices particularly sensitive to atmospheric conditions and in particular to gel.

These nucleators also work with a very low water flow and are generally supplied by a special circuit which regulates the flow and the pressure, which circuit is installed bypassing the water supply circuit under pressure at the different nozzles of the spray head.

The present invention provides a nucleation device which. by his design and its association with the spray head, allows overcome the drawbacks mentioned above.

It overcomes the disadvantages associated with the conditions atmospheric, such as freezing which causes the orifices to be blocked of flow due to the relatively small sections in which flows pressurized water.

It also makes it possible to get rid of complicated installations, by simplifying in a singular way, the means which make it possible to feed these nucleation devices.

The nucleation device according to the invention is defined in claim 1. It comprises means injection of a small jet of pressurized water into a large air stream speed, with a very high air / water ratio, and the air-water mixture is carried out either internally in a mixing chamber integrated into the head of spraying, either externally, that is to say outside of said head, and these water injection means at least are located in said head and soak in the water circuit which continuously supplies pressure to the nozzle (s) spraying and, simultaneously, said injection means.

Still according to the invention, the air / water ratio of this device nucleation is at least 200, and the injection of water into the air stream under pressure takes place through one or more orifices of very cross section small, according to a total section whose equivalent diameter is at most equal to 1 mm. This section particularly low makes it possible to achieve a significant pressure drop at level of the nucleator and above all avoids any recourse to a pressure reducing system when the pressurized water comes from the nozzle supply circuit of the spray head. The pressure in this nozzle supply circuit can vary significantly, without influencing the operation of the nucleation device.

Still according to the invention, the nucleation device which performs a external mixture has an air spray nozzle which is provided with a deflector to achieve a flat spectrum jet, and it includes a nozzle or nozzle for spraying water, the jet of which strikes the flat air flow at an angle of the order of 45 °.

According to an alternative embodiment, the nucleation device is presented in the form of a high pressure mini snow cannon supplied with air under pressure and directly in pressurized water by means of the channel of the spray nozzle (s), which mini barrel is present in the form of a cartridge implanted in the spray head and this cartridge extends between a pressurized air supply channel and the outer wall downstream of said head. by crossing at least one inlet channel of pressurized water to one or more spray nozzles.

Still according to the invention, the mixing chamber of the mini barrel is cylindrical shape and its diameter is slightly greater than the diameter of the nozzle, or end nozzle, which nozzle has an outlet the section, which is circular or oval, has a diameter equivalent to a maximum of 10 mm.

According to another arrangement of the invention, the orifice (s) which allow the injection of pressurized water into the mixing chamber, comprise a hole opening into said chamber, the diameter of which is of the order of 1 mm and the length of which is of the same order as said diameter, which hole can be arranged in the center of a large borehole or countersink diameter, at least ten times the diameter of said through hole, so that form a sort of diaphragm at the entry of the water jet into said mixing chamber.

The present invention provides, also in combination with these nucleators, a spray head whose capacities can for example, be easily modified as required.

According to the invention, the spray head with which the nucleation device, consists of a body that includes at least two spray nozzles supplied separately with pressurized water, which head has a foot which is arranged so as to allow its attachment to a pole, which pole comprises for example several water and possibly pressurized air supply pipes, which conduits are arranged in relation to orifices arranged in said foot to supply the different nozzles of said head.

According to another arrangement of the invention, the body of the head of spray consists of a molded part of annular or other shape, in light alloy for example, which part is provided with supply chambers pressure water spray nozzles, which chambers are for example obtained directly by molding, each of them being supplied by a channel arranged in the lower part of the body so to allow total emptying of said chambers when the spray head is inactive, which chambers are moreover adjacent, arranged side by side side, axially offset from the axis of the spray jet, and they are each crossed by axial drillings which make it possible to accommodate said cartridge-shaped spray nozzles, which cartridges have at least one orifice which opens into one of the chambers, to allow their supply of pressurized water.

The spray head can thus include families of nozzles; each family being fed by the same room.

Still according to the invention, the spray head comprises, upstream pressurized water spray nozzle supply chambers, a chamber supplied with pressurized air, and the cartridge of the nucleation passes through the various pressurized water chambers and leads to at its upstream end in said pressurized air chamber, which cartridge also has at least one orifice which opens into one of said pressurized water chambers, and in particular the main chamber arranged upstream of the others, to allow the injection of water into the air flow which circulates in said cartridge through the mixing chamber, and this air-water mixture is sprayed by the nucleator nozzle in the form of ice or snow.

The spray head with incorporated nucleation device according to a variant of the invention, comprises at least two nozzles so supplied separated by separate pressurized water circuits, these nozzles are arranged radially on the periphery of a tubular jacket whose axis is close to vertical under normal operating conditions, which jacket contains a core which is provided with radial partitions to divide sealing the internal space of said jacket in several chambers: - a main bedroom and - at least one secondary bedroom which is works after the master bedroom if necessary, which bedrooms are used to supply one or more nozzles, which core is provided with internal channels connected to said pressurized water circuits so as to supply each bedroom.

Still according to the invention, the upper part of the spray head includes a cap provided with at least one nucleation device arranged at side or in the field of the main chamber nozzle (s), which device is supplied with water and pressurized air, which feeds is carried out, for water, by the supply channel of said main chamber, which channel passes through said cap, and the air supply takes place at by means of a specific channel arranged in the core and in the cap, at the center of these.

Still according to the invention, the nucleation device is integrated radially in the head, crossing the tubular jacket and fitting into the central core to the pressurized air inlet channel.

According to a variant, the nucleation device comprises a cartridge constituting the mixing chamber and two spray nozzles for mixing air-water, each nozzle being oriented parallel to the faces of the dihedrons in which, for example, are aligned with the water spray nozzles under pressure.

In the different cases above, the body of the nucleation device soaks in the water circulating in the master bedroom, preventing freezing and blockage of the small opening (s) due to the permanent circulation of water in said room.

According to another provision of the invention, again with the aim of avoiding freezing phenomena in the head, the different channels supply chambers of said head open at the bottom of each room thus allowing a total emptying of the latter during stopping the installation.

• la figure 1 représente de façon schématique, un mode de réalisation d'une tête de pulvérisation susceptible d'être associée à un dispositif de nucléation selon l'invention ;
• la figure 2 représente de façon schématique et simplement fonctionnelle, une section du corps de la tête de pulvérisation et l'implantation d'une cartouche faisant office de buse de pulvérisation, alimentée par la chambre amont dudit corps ;
• la figure 3 représente, comme pour la figure 2, une section schématique du corps de la tête de pulvérisation avec une cartouche faisant office de buse, aménagée pour coopérer avec la chambre centrale ;
• la figure 4 représente comme précédemment, une cartouche faisant office de buse de pulvérisation, coopérant avec la chambre aval du corps ;
• la figure 5 représente l'alimentation des différentes chambres du corps de la tête de pulvérisation ;
• la figure 6 représente une élévation en coupe longitudinale et verticale d'une tête de pulvérisation selon un premier mode de réalisation du dispositif de nucléation selon l'invention;
• la figure 7 représente une vue de face de la tête de pulvérisation représentée figure 6 ;
• la figure 8 représente une vue de dos de la tête de pulvérisation représentée figures 6 et 7 ;
• la figure 9 représente d'une façon plus détaillée, le dispositif de nucléation installé en amont du corps de la tête de pulvérisation telle que représentée figures 6 à 8 ;
• la figure 10 représente une variante d'implantation du dispositif de nucléation dans la tête de pulvérisation, lequel dispositif de nucléation se présente sous la forme d'un mini canon à neige du type haute pression ;
• la figure 11 représente une variante de réalisation de la tête de pulvérisation selon l'invention avec une coupe verticale et axiale du dispositif de nucléation ;
• la figure 12 représente d'une façon détaillée et agrandie, un orifice d'introduction d'eau sous pression dans la chambre de mélange du dispositif de nucléation ;
• la figure 13 représente une vue de dessus de la tête de pulvérisation ;
• la figure 14 représente la tête en coupe selon 14-14 de la figure 11 ;
• la figure 15 représente la tête en coupe selon 15-15 de la figure 11 ;
• la figure 16 représente la tête en coupe selon 16-16 de la figure 11 ;
• la figure 17 représente une variante de la tête de pulvérisation représentée figure 11, en coupe verticale passant par le dispositif de nucléation ;
• la figure 18 représente une coupe selon 18-18 de la figure 17 ;
• la figure 19 représente une variante d'un dispositif de nucléation à deux buses, commun à deux rangées de buses de pulvérisation.

The invention will be further detailed with the aid of the following description and the appended drawings given for information and in which:

• FIG. 1 schematically represents an embodiment of a spray head capable of being associated with a nucleation device according to the invention;
• Figure 2 shows schematically and simply functional, a section of the body of the spray head and the implantation of a cartridge acting as a spray nozzle, supplied by the upstream chamber of said body;
• 3 shows, as for Figure 2, a schematic section of the body of the spray head with a cartridge acting as a nozzle, arranged to cooperate with the central chamber;
• Figure 4 shows as before, a cartridge acting as a spray nozzle, cooperating with the downstream chamber of the body;
• FIG. 5 represents the supply of the different chambers of the body of the spray head;
• FIG. 6 represents an elevation in longitudinal and vertical section of a spray head according to a first embodiment of the nucleation device according to the invention;
• Figure 7 shows a front view of the spray head shown in Figure 6;
• Figure 8 shows a rear view of the spray head shown in Figures 6 and 7;
• Figure 9 shows in more detail, the nucleation device installed upstream of the body of the spray head as shown in Figures 6 to 8;
• FIG. 10 shows a variant implantation of the nucleation device in the spray head, which nucleation device is in the form of a mini snow cannon of the high pressure type;
• FIG. 11 represents an alternative embodiment of the spray head according to the invention with a vertical and axial section of the nucleation device;
• Figure 12 shows in detail and enlarged, an orifice for introducing pressurized water into the mixing chamber of the nucleation device;
• Figure 13 shows a top view of the spray head;
• Figure 14 shows the head in section along 14-14 of Figure 11;
• Figure 15 shows the head in section along 15-15 of Figure 11;
• Figure 16 shows the head in section along 16-16 of Figure 11;
• FIG. 17 represents a variant of the spray head represented in FIG. 11, in vertical section passing through the nucleation device;
• Figure 18 shows a section on 18-18 of Figure 17;
• FIG. 19 shows a variant of a nucleation device with two nozzles, common to two rows of spray nozzles.

The spray head may appear, as shown in Figure 1, under the shape of an annular sleeve 1 carried by a base or foot 2. This head has on its downstream face 3, several orifices represented by crosses. The water which arrives under pressure at the level of these orifices, is sprayed axially.

This spray head 1 is arranged to receive at the level of aforementioned orifices, several families of spray nozzles such as example family number 1 which includes the nozzles marked 1.1, 1.2, 1.3 ... etc, up to 1.6, as well as a family number 2 marked 2.1, 2.2, for example and a family number 3 identified 3.1, 3.2.

Each family 1, 2, 3 is supplied with pressurized water in a way distinct, according to characteristics specific to each of them.

We can thus, from a single head, obtain a wide variety of sprays in terms of flow rate in particular, adapted to all needs.

To achieve this versatility, the head 1 and in particular its body, includes several chambers as shown in Figures 2 to 5, each of chambers used to supply a family or series of spray nozzles.

Figures 2 to 5 show, schematically and simply functional, a section of the body of the spray head. This body, of annular shape, figure 1, can just as well be rectilinear or other like for example in the form of a tuning fork; it has several bedrooms and particular three chambers in the detailed examples figures 2 to 5. Thus, one finds an upstream chamber 5 constituting the main chamber, a chamber central 6 and a downstream chamber 7

These rooms are arranged side by side, separated by partitions 56 for adjacent rooms 5 and 6, and 67 for rooms 6 and 7.

These different chambers are drilled along an axis 8 which is oriented parallel to axis 9 of the spray head. This borehole crosses the wall downstream 3, the partitions 56 and 67 and, as shown in FIGS. 2 to 4, the upstream wall 10 of the body of the head.

This drilling makes it possible to house a spray nozzle 11 which is presented in the form of a cartridge 12 closed at its upstream end and provided with a nozzle 13 at its downstream end.

The seal between the cartridge 12 and the various walls of the chambers and of the body of the head 1 is produced by means of seals 14. The cartridge 12 is immobilized by any appropriate means on the body 1.

The spray nozzle 11 shown in FIG. 2 is a nozzle which corresponds to family number 1. This nozzle is in communication with the chamber 5 which receives pressurized water, as shown in FIG. 5, at by means of a supply line 15.

Similarly, rooms 6 and 7 are supplied in a separated and respectively by conduits 16 and 17.

Each room 5, 6 or 7 can therefore be used to power the different families of nozzles.

Thus, as shown in Figure 2, the chamber 5 supplies the nozzles of the family number 1. The cartridge 12 has in fact one or more orifices 21 which allow to connect the chamber 5 with the nozzle, the water being ejected through the nozzle 13.

Figures 3 and 4 represent, like Figure 2, a section of chambers 5, 6 and 7 as well as nozzles 11.

FIG. 3 shows a nozzle 11, the cartridge 12 of which includes orifices 22 which allow said nozzle to be in communication with the chamber 6 for spraying pressurized water through the nozzle 13.

Figure 4 shows the nozzle 11 and in particular its cartridge 12 provided orifices 23 which put said nozzle in communication with the chamber 7.

FIG. 1 illustrates, for a first embodiment, a head spray which comprises an annular sleeve-shaped body provided with a foot 2. The body and foot 2 are preferably made by molding so monobloc, in light alloy. Chambers 5, 6 and 7 which are annular in shape, can be obtained directly by molding.

The foot 2 has the channels corresponding to the pipes 15, 16 and 17 shown in Figure 5. This leg 2 is also arranged to be able to be fixed for example on a pole 25 like that described in the document FR-2,743,872.

This pole 25 which appears in thin broken lines in Figure 6, includes tubes obtained for example directly by spinning, which allow supplying pressurized water to the chambers of the spraying device and, in addition, thanks to a central pipe, to supply air under pressure, a nucleation device or nucleator.

The distribution of pressurized water supplies appears in Figure 8; with, in the center, the inlet of channel 18 for the passage of air. This channel 18 is used to supply pressurized air to the nucleation device 27 which is shown in section in Figure 6 and in more detail in Figure 9.

This nucleation device comprises a support 29 in the form of a bar vertical centered in the median vertical plane of the spray head and fixed to the upstream inlet of said head. This support 29 comprises a channel 30 which is used for passage of pressurized air and a channel 31 which serves for the passage of water under pressure, which channel 31 is supplied by means of a bypass 32 or tapping on the supply channel 15 of the chamber 5 which constitutes the master bedroom.

The channel 31 also extends to the upper part of the support 29 and it allows the supply of a particular nozzle 11 'which passes through the chambers 5, 6, 7, and the upper part of the support 29. This nozzle 11 'is present under the form of a cartridge also tightly mounted in the body 1 and this nozzle 11 ′ is provided, at the level of the channel 31, with orifices 33 which allow the passage of water under pressure to the spray nozzle 13.

A circulation of water is thus obtained in the support 29 and as detailed below, in the nucleator 27 proper, which has the effect avoid freezing or even defrost the water and / or air jet of said nucleator, when from the commissioning of the installation or during its operation.

The channel 30 arranged in the support 29 is in communication with the channel 18 which conveys the air under pressure.

Figure 9 shows in more detail, the nucleator 27 well said. This nucleator comprises in the example shown, a nozzle central 35 which sprays the air brought under pressure through the channel 30, and a nozzle 36 to spray the water which is brought under pressure through the channel 31.

Note that the pressurized air arrives in a room 37 fitted in the support 29 and centered on the axis 9 of the spray head. This chamber 37 is closed by a cap 39 fixed at the rear, that is to say in upstream of the support 29 and this cap supports a filter 40 which is interposed between the channel 30 and the nozzle 35.

The nozzle 35 is mounted on a drilled block 41 which is fixed on the downstream face of the support 29. This block 41 includes an axial cavity centered on the axis 9 for house the nozzle 35 and there is a chamber 42 arranged around the nozzle 35, substantially at mid-length, which chamber 42 communicates with channels 43 which allow a junction of the channels 31 arranged in the part lower and in the upper part of the support 29. These channels 43 establish a continuous circulation of water in the drilled block 41, around the nozzle 36 and around the nozzle 35.

The nozzle 35 is a nozzle of the type provided with a deflector 45 which allows to get a flat spray. This flat air jet is struck by the water jet from the nozzle 36. This nozzle 36 is in fact placed under the nozzle 35, making an angle of the order 45 ° with axis 9 of nozzle 35. By striking the air jet, the water jet turns into particles of ice or snow that will seed the jets of different nozzles 11 and 11 'in service.

The orifice 38 of the nozzle 36 has a very small diameter, less than 1 mm. This nozzle 36 soaks in the circulating water to feed the nozzle 11 ', which avoids freezing and plugging of the orifice 38.

In addition, this orifice 38, by its very small size, makes it possible to obtain a jet regular whatever the pressure in the supply circuit of the nozzle 11 '.

The above nucleation device is of the external mixing type that is, water and air are mixed outside the head of spraying but in the central cavity 39 of the body and upstream of the nozzles 11. The air-water mixture is carried out with a very large ratio at least equal to 200.

FIG. 7 shows the different nozzles 11 distributed over the downstream face 3 of the head body as well as the nozzle 11 'arranged at the upper part in the vertical median plane. The jets of these different nozzles are for example flat spectrum sprinklers arranged in parallel planes of each other way to form strata.

We also find in the median vertical plane the nozzle 35 arranged at the center of the spraying device as well as the nozzle 36 which projects a jet pressurized water in the jet of air from the nozzle 35.

The different nozzles 11 and the nozzle 11 'cause and induce a air flow in the body of the head 1 and around said body, favoring the water / air mixture for snow formation.

Figure 8 shows, seen from the rear, the spray head fitted with the nucleation device 27.

We note, on the upstream face of the body of the head, the various screws 50 which allow the assembly of the nozzles 11 and in particular the assembly of the cartridges 12 forming these nozzles.

The nozzle 11 'is also fixed by means of a screw 51 which appears Figures 6 and 8.

FIG. 10 represents an alternative embodiment in which the nucleator is directly integrated into the body of the spray head. This nucleator actually comes in the form of a particular cartridge in form of mini high pressure snow cannon, located at the top of the head body 1.

The body also has chambers 5, 6 and 7 which are supplied in pressurized water, a chamber 4 arranged upstream of the chambers previous, also annular in shape, and which is supplied with air under pressure by means of channel 18 which is arranged in foot 2 and communicates with said chamber 4.

A particularly compact spraying device is thus obtained and homogeneous on which there is a nucleator consisting of a mini gun 52 and conventional spray nozzles 11 distributed over the downstream face 3 of the body of the head according to several families, each of these families being supplied by means of chambers 5, 6 or 7 as required with good sure all possibilities to realize a kind of mixing of nozzles.

The nozzle or mini cannon 52 comprises a cartridge 53 which passes through tightly chambers 5, 6 and 7.

This cartridge 53 is provided with an axial cavity which acts as a mixing chamber 54 and its wall is pierced with at least one orifice 55 located in chamber 5, which chamber is supplied with pressurized water. The cartridge 53 thus soaks in the supply water of the nozzles 11 which prevents freezing of the opening (s) 55.

The orifice (s) 55 have a cross section which corresponds or which is even less than the circular section of an orifice whose diameter would be 1 mm. The pressure drop caused by this or these orifices allows operation of the nucleator regardless of the water pressure in the bedroom 5 in particular.

The upstream wall of the mixing chamber 54 has orifices 56 to allow the passage of pressurized air from chamber 4.

The water-air mixture takes place in chamber 54 and exits through the nozzle or nozzle 57. It is a mixture with a high air / water ratio, at least equal to 200.

The upstream end of the cartridge 53 is in the form of a central rod 59 at the level of the channel 60 which connects the chamber 8 with chamber 54 of the mini cannon.

Upstream of the rod 59, there is the assembly screw 50 'which allows fix the cartridge 53 constituting the mini barrel 52, on the body 1 thanks to the shoulder 61 located at the downstream part of said cartridge. This shoulder is also found, identically. on the cartridges 12 detailed previously.

The spray head shown in Figure 1 and Figure 11 is more particularly intended to be installed also at the end of a pole as in the case of the installation described in patent FR-2,743,872 of the Applicant.

Between the spray head 1 proper and the upper end of the mast 25, a part 63 can serve as an intermediary, as shown in the figure 11. This piece 63 is slightly bent to give head 1 a favorable inclination, close to vertical, or slightly inclined to cause the water to spray at an angle that promotes projection over the greatest possible distance depending on needs and site.

The head 1, FIG. 11, consists of a tubular jacket 64 and a cylindrical core 65 centered in said jacket, the diameter of which is lower than that of said jacket to allow the passage of water under pressure. The core 65 has circular radial partitions which divide the internal space between the jacket 64 and said core, in several chambers.

So we find - a master bedroom 66, at the top of the spray head, delimited by the partitions 67 and 69 of the core 65, - a intermediate chamber 70 delimited by partitions 69 and 71 and a chamber lower 72 delimited by partitions 71 and 73. Partition 73 is located at the lower part of the core 65 and the partition 67 at the upper part.

Each chamber supplies one or more sprinklers 75 located on a or several generatrices of the cylindrical envelope of the jacket 64.

Room 66, which is the main room, can have several nozzles 75 distributed over several generators.

The sprinklers 75 in rooms 70 and 72 are sprinklers which are implemented independently of those of the room 66, depending on climatic conditions to increase according to these climatic conditions the quantities of snow produced.

Each room is fed by a channel which leads to its part lower.

Note, FIG. 11, the orifice 76 which opens into the chamber 66 at its lower part, that is to say at the level of the partition 69 of the core 65. A orifice 77 opens at the bottom of the chamber 70 at the level of the partition 71, and an orifice 79 opens into chamber 72 at the level of the partition 73.

The seal between the jacket 64 and the various partitions 67, 69, 71 and 73, is produced by means of O-ring seals 80 arranged in the thickness of said partitions.

The lower part of the core 65 has a base 81 in the form radial shoulder, on which the lower end 82 of the jacket 64. The core 65 extends above the upper end 83 of the shirt 64 and it is covered by a cap 84 which is fixed by screws 85 taken in the upper cylindrical end 86 of the core 65. The joint plane 87 between the shirt 64 and the cap 84 is disposed between the O-ring 80 of the partition 67 and an O-ring 89 arranged in a groove arranged in the upper cylindrical end 86 of the core 65.

The cap 84 is positioned relative to the core 65 in a way specifies either by means of an original distribution of the screws 85 and / or a pin centering 90.

This position of the cap 84 makes it possible to place the shirt 64 in a precise position also by means of the centering pin 90 interposed between both at the joint plane 87.

The cap 84 includes at least one nucleation device 91 which makes acts as nucleator, to make particles of ice or snow which will then seed the different jets coming from the nozzles 75 of the spray head. This nucleation device 91 comprises a body cylindrical in the shape of a cartridge 92 inserted radially into an orifice fitted for this purpose in the cap 84, and a nozzle or nozzle 93 which is preferably oriented towards the jets of the different nozzles or nozzles 75 so to carry out the seeding.

The cartridge 92 of the nucleation device is fixed by any means suitable in cap 84, for example by screwing; it will be detailed further.

75 sprinklers are supplied with pressurized water from channels which bring the pressurized water into the different rooms. The distribution of these channels in the core 65 appears on the different sections shown in Figures 14 to 16 and, in dotted lines in Figure 11.

The nucleation device 91 which in fact constitutes a sort of mini high pressure snow cannon with very high air / water ratio, at least equal to 200, is supplied with pressurized water by one of the channels supply of the rooms and in particular by means of the channel which feeds master bedroom 66.

This mini cannon is also supplied with pressurized air. We note, in Figures 14 to 16 and Figure 11, a channel 95 disposed in the center of the core 65, which extends into the cap 84, in the form of a blind hole central. This channel 95 allows the pressurized air to be brought up to the level of the nucleation device 91 and in particular at the downstream inlet of the mixing of said device, detailed below.

Chamber 66 is arranged just below the nucleation device 91; it is supplied with pressurized water by means of a channel 96 which also extends into the cap 84, which cap has a annular cavity 97 which is crossed by the cartridge 92 of the nucleation 91. Thus the channel 96 extends over the entire length of the nucleus 65; he communicates with the annular cavity 97 fitted in the cap 84 and a second channel 99 arranged in the core 65 extends from said cavity 97 of the cap 84, to the lower part of chamber 66, opening at level of the orifice 76 in said chamber to supply the latter.

Note, Figures 11 and 14, that the chamber 66 supplies several jets 75, arranged in pairs on two different generators. These sprinklers 75 are aligned vertically with the nozzles arranged at the level of the others chambers 70 and 72 and also with the nucleation devices 91.

As previously indicated, port 76 is located at the bottom of chamber 66. We note, in the extension of this orifice 76, a small channel 100 of small diameter, which extends between channel 99 and channel 96, arranged in such a way that it allows total drainage of the water located in the chamber 66, when the water supply is cut off.

The diameter of this channel 100 is of the order of 1 / 5th of the diameter of the channels 96 and 99 in order to maintain a preferential circulation of water under pressure, in the cavity 97 of the cap 84.

Figure 15 shows a section at the orifice 77 which allows the supply of the chamber 70 and of the nozzles 75. This orifice 77 is supplied by means of a channel 101 which extends axially in the core 65.

We also find figure 15, the channel 95 arranged in the center of the core in which the compressed air circulates and the channel 96 which serves to supply the chamber 66 and at the same time to power the nucleation devices 91 while ensuring circulation around these nucleation devices constant water to avoid the phenomenon of freezing.

FIG. 16 corresponds to a section at the level of the orifice 79 which serves to supply the chamber 72 and the lower nozzles 75. This chamber 72 is supplied by means of a channel 102 which extends parallel to the channel 101, at the channel 96 and to the central channel 95 which is used for the passage of compressed air.

Note that channel 102 is located under channel 99, centered practically on the same axis. The lower end of channel 99 and the end channel 102 are separated by a distance which corresponds substantially at the height of the chamber 70.

Figure 12 shows the detail of one of the water introduction holes under pressure in the cartridge 92 of the nucleation device 91.

This cartridge 92, of tubular shape, has in its central part an axial chamber 103 which opens downstream from the side of the nozzle 93 and which is open upstream on channel 95 in cap 84.

The diameter of the axial mixing chamber 103 is substantially greater than the diameter of the outlet nozzle 93. The pressurized water used to supply the main chamber 66, is introduced radially into the mixing chamber 103 by means of orifices 94, preferably three orifices distributed over the periphery of the cartridge 92, the jets of which can be concurrent on the axis of said mixing chamber.

These orifices 94, one of which is shown in section and in an enlarged manner FIG. 12, are situated rather upstream of the mixing chamber 103.

As shown in Figure 12, the outer wall of the cartridge 92 is drilled radially with a first hole 104 whose diameter is less than 1 mm, and a second hole or counterbore 105 of much larger diameter. The diameter of hole 105 is of the order of ten times the diameter of hole 104. The length of hole 104 is of the same order as its diameter. So the water under pressure is injected into the mixing chamber 103 while crossing a sort of diaphragm which allows the 91 nucleation device to operate regardless of the pressure of the water introduced into the chamber main 66 for feeding sprinklers 75.

By way of example, the nucleation device can present the following characteristics: for an output at the nozzle 93 of the order 5.2 mm, we will adopt a diameter for the mixing chamber 103 of of the order of 7 mm and each of the three orifices 104 will have a diameter of the order of 0.6 mm.

The functioning of this nucleation device 91 is similar to a mini snow gun of the high pressure type, in which the air / water ratio is very important, at least equal to 200 and preferably much higher.

The spray head 1 and in particular the base 106 of the core 65 is fixed by means of screws 107 to the intermediate connection 63, which connection 63 is itself fixed by means of screws, not shown, on the end of the mast 25.

Figure 13 shows the distribution of the screws 85 which allow to fix the cap 84 on the upper end of the core 65. The distribution of the screws is such, as previously mentioned, that it imposes a precise orientation of the head relative to the core 65 and consequently an orientation also defined for the jacket 64 which carries the nozzles 75, by means of the centering pin 90 interposed between said jacket and said core.

Figure 17 shows a variant of the spray head shown in Figure 11.

In this variant, we find the same arrangement of the rooms 66, 70 and 72. A simplification appears due to the implementation of the nucleation 91 which are incorporated directly at the bottom of room 66.

This figure 17 shows a portion of the intermediate piece 63 on which is fixed the core 65 '. The core 65 'is in the form of a molded and machined part, made of light alloy, and looks like a sort of drawer hydraulic threaded in an envelope 64 '. This 64 'envelope is itself consisting of a machined molded part, made of light alloy, held between the lower shoulder 81 of the core and the cap 84 'which is fixed by screws 85' to the upper end 86 'of the core 85'.

Rooms 66, 70 and 72 are, as before, arranged between partitions. Thus we find the upper partition 67 which delimits with the partition 69, the annular chamber 66.

The annular chamber 70 is delimited by the partition 69 and the partition 71. This partition 71 is interposed between the chamber 70 and the chamber 72, which annular chamber 72 is delimited at its lower part by the partition or shoulder 73.

To facilitate assembly, the partitions may have diameters which slightly increasing from the end of the core to its base 81.

These chambers are supplied as before for the head represented in FIG. 11, by conduits which appear in thin dashed lines and which open out through a radial borehole at the bottom of each of said chambers. These radial holes are also inclined so as to allow efficient and total emptying of each of the chambers to avoid freezing when spraying stops.

Thus, there is the orifice 76 which allows the introduction of water under pressure in room 66. This introduction in room 66 takes place directly at the bottom without passing as above, figure 11, by hat 84.

The chamber 70 is supplied by the orifice 77 and the chamber 72 is supplied by port 79.

A central duct 95, in the core 65 ', makes it possible to bring the air under pressure to the nucleation device 91. This nucleation device is presented as previously in FIG. 11, in the form of a cartridge 92. This cartridge 92 passes through the wall of the envelope 64 ′ in a sealed manner, and it is for example screwed onto this wall; it fits into a hole 110 arranged radially in the core 65 ', which orifice opens into the channel 95 for supplying pressurized air.

Thus, the nucleation device is supplied with pressurized air at the upstream end of its mixing chamber 103, and the water supply under pressure, is effected by means of one or more orifices 94 arranged in the wall of the cartridge 92.

These orifices 94 are located in the chamber 66, supplied with water under pressure at the same time as the spray nozzles 75.

The cartridge 92 of the nucleation device 91 soaks in water which circulates in chamber 66 which avoids the phenomena of freezing and plugging the water injection holes in the mixing chamber 103.

As shown in Figure 18, two devices can be positioned nucleation 91, making an angle close to 90 ° between them. These devices nucleation are arranged at the bottom of the main chamber 66, each under a vertical row of spray nozzles 75, which nozzles are represented three in number Figure 17, on the same line and in the same vertical plane.

In this vertical plane in which there is a nucleator 91 and the nozzles 75 of the main chamber 66, there are also the nozzles of spraying 75 associated with chambers 70 and 72 located under the chamber main 66.

Note also that the nucleation devices 91 are used to angularly position the casing 64 ′ of the spray head relative to to the core 65 'due to their fitting in radial cavities of this latest.

The nozzle 93 of the nucleation device 91 is oriented like all the sprinklers 75, perpendicular to the longitudinal axis 109 of the head 1. It is arranged under the nozzles 75 of the main chamber 66 and not above as in the case of the head shown in Figure 11.

Figures 17 and 18 show that the core 65 'has a countersink 111 at each of the holes 110 in which the cartridge is fitted 92 nucleation devices 91.

These counterbore allow good circulation of water around of the cartridge 92 of the nucleation devices 91.

The orifices 94 of the nucleation devices shown in FIG. 17, correspond to the orifices 94 represented in FIG. 12 in conjunction with FIG. 11.

Figure 19 shows an alternative embodiment of the device assembly nucleation on the spray heads in the form of represented columns Figures 11 and 17.

The nucleation device 91 ′ comprises a cartridge 92 ′ which is provided two nozzles or nozzles 93 '. The cartridge is centered in the median plane dihedral formed by the two rows of spray nozzles 75 while the nozzles 93 'are oriented parallel and respectively to each face said dihedral.

This particular arrangement allows for seeding with a single nucleator, which nucleator has, in this case, orifices 94 in the cartridge 92 ′, for the injection of water, which are substantially superior to those of previous assemblies. We reduce even more, from this way the risk of freezing of the orifice (s) 104 in particular.

Claims (11)

1. A nucleation device (27) combined with a water spray head (1,2) provided with at least one high-pressure water supplied nozzle (11), for the generation of artificial snow, which device comprises pressurised injection means (36) of a small water jet into an air stream at high speed, with very high air/water ratio, at least equal to 200, which mixture air/water takes place either internally in a mixing chamber integrated in the spray head or externally, i.e. outside the said head, and whereas these water injection means (36) at least are located in the said head (12) and are partially immersed in the water system that supplies the spray nozzle(s) (11), which system supplies simultaneously the said water injection means, characterised in that the injection of water into the air stream takes place through one or several orifices of very small cross section, whose diameter is about 1 mm.
2. A nucleation device of the external mixing type according to claim 1, characterised in that it comprises a compressed air spray nozzle (35) provided with a baffle in order to produce a flat spectrum jet, and it comprises a nozzle or tip (36) for water spraying, whose jet strikes the flat air flow with an angle of about 45°.
3. A nucleation device of the internal mixing type according to claim 1, characterised in that it is as a high-pressure mini snowmaker, comprising of a cartridge located in the spray head, which cartridge comprises a mixing chamber (54, 103) whose upstream end leads to a pressurised air supply duct or chamber (60, 95) and extends downstream to the tips (57, 93) and the wall of the spray head, with between both at least one orifice (55, 94) for injecting water into the said chamber, which orifice (94) is located in the supply system of the spray nozzle(s) (11, 75) of the said head.
4. A nucleation device according to claim 3, characterised in that the mixing chamber (54, 103) is cylindrical in shape and its diameter is slightly greater than the diameter of the end nozzle or tip (57, 93), which nozzle has an outlet orifice whose global section has a diameter equivalent to 10 mm maximum.
5. A nucleation device according to claim 4, characterised in that the orifice(s) (94) enabling to inject pressurised water into the mixing chamber (103), comprise a hole (104), whose diameter is lower than 1 mm and whose length is in the same order as the said diameter, and, upstream of this hole (104) one hole (105) whose diameter is about ten times the diameter of the said hole (104) thereby forming a kind of membrane at the inlet of the mixing chamber.
6. A nucleation device according to any one of claims 1 to 5, characterised in that it is integrated in a spray head (1) consisting of a body which comprises at least two spray nozzies (75) supplied separately with pressurised water, which head comprises a foot (2, 63) that is provided in order to be attached to a post (25), which post comprises for instance several water supply ducts and one pressurised air supply duct, which ducts are arranged in relation to orifices provided in the said foot in order to supply the various nozzles of the said head.
7. A nucleation device according to claim 6, characterised in that the nozzles (75) are provided on the body of the spray head, which body consists of a moulded part of light alloy, which part is provided with supply chambers for the said spray nozzles, which chambers (5, 6, 7) are obtained directly by a moulding process or other and are adjacent, arranged side by side, offset axially and each traversed by axial drillings that enable to accommodate the said cartridge-like spray nozzles (11), which cartridges comprise at least one orifice that leads to one of the said chambers, to supply them with pressurised water.
8. A nucleation device according to claim 7, characterised in that the spray head comprises, upstream of the chambers (5, 6, 7), a chamber (4) supplied with pressurised air and in that the cartridge (53) making up the mini snowmaker goes through the different chambers (5, 6, 7) in a sealed manner, which cartridge leads at its upstream end to the said chamber (4) and comprises at least one orifice (55) that leads to one of the chambers (5, 6, 7) and in particular to the main chamber (5) to enable injection of pressurised water to the air stream that circulates at high speed in the mixing chamber (54).
9. A nucleation device according to claim 6, characterised in that the nozzles (75) are arranged radially on the periphery of a tubular jacket (64) enclosing a core (65) provided with radial walls in order to divide in a sealed manner the internal space of the said jacket into several chambers : a main chamber (66) and at least one secondary chamber capable of using one or several complementary nozzles, which core (65) is provided with internal ducts connected to the pressurised water systems in order to feed each chamber at its lower portion thus enabling total drainage of these chambers once the installation has stopped.
10. A nucleation device according to claim 9, characterised in that it comprises a cartridge (92) arranged on the plane of a row of nozzles (75) for seeding each row, or a cartridge (92') arranged on the middle plane of the dihedron delineated by two rows of nozzles (75) for direct seeding of each row via two tips (93') oriented parallel and with respect to each face of the said dihedron.
11. A nucleation device according to any one of claims 9 or 10, characterised in that the cartridge (92, 92') goes through the main chamber (66) and is shrink-fitted into the central core (65) leading to the pressurised air supply duct (95).

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