FR2854944A1 - Artificial snow generation reproduces snowflake by creating conditions in high atmosphere and discharges flakes in one-dimensional gas flow - Google Patents

Abstract

Artificial snow generation comprises reproducing the conditions for forming snow in a high atmosphere in an open chamber that is independent of outside climatic conditions, employing the following phases: creating a one-dimensional air flow at a temperature independent of the outside temperature and transforming the linear flow into a swirling flow; creating a static pressure independent of the atmospheric pressure; forming snow flakes by nucleation from a supporting core of ice, and discharging the flakes into the outside air with the aid of the stable one-dimensional air flow. Artificial snow generation comprises reproducing the conditions for forming snow in a high atmosphere in an open chamber that is independent of outside climatic conditions, employing the following phases: creating a one-dimensional air flow at a temperature independent of the outside temperature and transforming the linear flow into a swirling flow; creating a static pressure independent of the atmospheric pressure; forming snow flakes by nucleation from a supporting core of ice, and discharging the flakes into the outside air with the aid of the stable one-dimensional air flow. The one-dimensional flow is produced by a low-pressure compressor with a turbine surrounding a staged high-pressure compressor with a convergent surface that accelerates the flow and leads to a collar linked to a divergent surface forming the start of a second circuit. The plant also has an Archemedes screw with temperature, hygrometry, pressure and speed sensors, and low- and high-pressure diffusers (30, 31) for the snowflakes.

Description

Method and installation for making artificial snow

  The invention relates to the technical sector of snow cannons and the manufacture of artificial snow commonly known as artificial snow.

  For many years, the equipment of winter stations in snow cannons has been more and more common to compensate for the lack of snow and also the very large variations in an acceptable level of snow on the slopes during a winter season. full winter. 10 Global warming causes a change in the seasons, climatic periods of cold, rain or drought more accentuated and in very short periods of time.

  As for winter sports, at low and medium altitudes, and even sometimes at high altitudes, the lack of snow or its insufficiency, during all or part of a season, can have disastrous economic effects for the municipalities and the economic sectors of activity concerned.

  To overcome this situation, snow cannon installations have been proposed which are supposed to respond to the problems raised.

  In practice, the snow guns existing on the market operate under particular climatic conditions and more specifically when the outside ambient temperature at the locations where the guns are located is within a range of + 1 ° C. to −4 ° C. These conditions are therefore very restrictive. In addition, the quality of the snow produced varies according to the installations used in small proportions and always for snow heavily loaded with water. Pollution of the ambient air is also a constraint which influences the grains of ice produced which will solidify with the particles in the air. The behavior over time of these grains therefore remains very uncertain.

  Various embodiments have been developed to try to remedy these drawbacks, but without success. The Applicant was able to note that there was no installation for manufacturing artificial snow capable of overcoming the ambient outside temperature, and which could allow the manufacture of snow in very wide temperature ranges between - 30 C and + 15 C.

  The Applicant's approach was to reconsider the very concept of making artificial snow according to current methods, by analyzing the natural climatic phenomena allowing snow to be obtained. This particularly complex study, involving a large number of mathematical calculations in the control of the circulation of fluids, had the objective of transferring the climatic conditions found at very high altitude in the atmosphere into an ambient environment on earth with a view to the creation of artificial snow. It was therefore necessary to take into account parameters such as pressure, temperature, humidity, air speed. Controlling these parameters is particularly delicate, especially in the context of a low altitude reconstruction in areas where 25 artificial snow requirements are required.

  Numerous searches were therefore carried out by the Applicant to arrive at the design of a specific process and installation meeting the objectives mentioned above.

  According to a first characteristic, the process for manufacturing artificial snow is remarkable in that it consists in reproducing in situ in an autonomous and open enclosure free from the external climatic conditions of artificial snow, by reproducing the conditions for the production of snow in the upper atmosphere, and in that it implements the following phases: - creation of a one-dimensional flow at a temperature independent of the outside temperature and transformation of the linear air flow into a vortex flow, - creation of a static pressure independent of atmospheric pressure, - manufacture of an ice support core of the snowflake to be obtained, - creation of the snowflake by nucleation, evacuation of the flakes in an external medium transported by the stable gas stream of the one-dimensional flow. According to another characteristic, the installation for the manufacture of artificial snow implementing the method is remarkable in that it comprises inside an open autonomous enclosure arranged in situ in a place of production of artificial snow: - means for creating a one-dimensional flow at a temperature independent of the outside temperature, and the transformation of the linear flow into a vortex flow, - means allowing the creation of a static pressure independent of atmospheric pressure, - means allowing the manufacture of an ice support core of the snowflake to be obtained, - means allowing the creation of the snowflake by nucleation, - means allowing the evacuation of snowflakes in an external medium, transported by the stable gas stream of the flow dimensional.

  These and other characteristics will become apparent from the following

the description.

  To fix the subject of the invention illustrated in a nonlimiting manner in the figures of the drawings o: - Figure 1 is a schematic view of the installation illustrating the juxtaposition of its different components; - Figure 2 is a perspective view illustrating, outside the housing, the general configuration of the components; FIG. 3 is a partial view on a large scale illustrating the primary air mixer; - Figure 4 is a partial view on a large scale of the secondary air mixer; - Figure 5 is a partial view on a large scale and front of the primary vortex; - Figure 6 is a view according to Figure 5 in perspective of the primary vortex; - Figure 7 is a partial view on a large scale of the vortex isobaric layers; - Figure 8 is a partial view on a large scale of the low pressure secondary vortex; FIG. 9 is a partial view on a large scale of the secondary air mixer with saturation base; - Figure 10 is a view of the mixer according to Figure 9 including the secondary, low and high pressure vortices; - Figure 1 1 is a large-scale view illustrating the secondary high pressure vortex 10; - Figure 12 is a view illustrating the isobaric curves - Figure 13 is a view showing the installation in its components for the manufacture of the ice core for its evacuation; - Figure 14 shows the vortex mixer with cold water vapor arrival; - Figure 15 is a view similar to Figure 14 in perspective view; - Figure 16 is a perspective view of the components of the installation in phases 1, 2 and 3; FIG. 17 is a perspective view of the components of the installation in phases 4 and 5; - Figure 18 is a schematic plan view of the installation in phases 1, 2 and 3; FIG. 19 is a schematic plan view of the installation in phases 4 and 5; In order to make the object of the invention more concrete, it is now described in a nonlimiting manner illustrated in the drawings.

  In order to describe the installation which is the subject of the invention, reference should be made to the main phases of the process from which said installation was designed. Consequently and in relation to the objective of reproducing in-situ conditions for making snow in the upper atmosphere, the process allowing the manufacture of artificial snow in an outside temperature range between - 30 C and + 15 C consists of the implementation of the following main operating phases: creation of a one-dimensional flow at a temperature independent of the outside temperature and transformation of the linear air flow into a vortex flow; - Creation of a static pressure independent of atmospheric pressure; - manufacture of an ice support core of the snowflake to be obtained; - creation of the snowflake by nucleation; - evacuation of the flakes in an external environment, transported by the stable gas stream of the one-dimensional flow. The different operating phases are then specified with the description of the installation which is thus arranged to allow its implementation.

  To facilitate the reading of the drawings and their understanding, the direction of flow flow is represented whenever necessary by E for entry into the component or part of the installation, and by -> S for the exit.

  All the components of the installation are located in a single external fairing (C) grouping them together and making it possible to have an open autonomous installation of small relative size. This installation is also arranged relative to or above a cryogenic tank (29) with plates allowing the supply of water in certain operating phases of the process according to the invention.

  In the continuation of the description of the invention, we will successively describe the various components relating to each main operating phase for the manufacture of artificial snow, it being considered that all the components are arranged in succession from one another, thus as shown in the overview in FIG. 1. 15 -1 First phase: We now describe the initial phase of creation of the one-dimensional flow at a temperature independent of the outside temperature for its transformation from a linear flow to a vortex flow. We refer to Figures 1 to 6.

  The creation of the one-dimensional air flow is achieved by the use of an axial compressor, low and high pressure, which determines the most stable gas stream possible. The low pressure compressor (1) with turbine (la) which is located upstream is at the inlet of the installation and surrounds the high pressure compressor (2). The latter has four o stages (2a, 2b, 2c, 2d) of compression for obtaining a flow at positive temperature and at high speed and pressure. The low pressure compressor is determined and calculated to obtain a flow of air at neutral temperature around 0 * C by producing a large quantity of air at high speed and at high pressure by surrounding the flow of high pressure air. The suction of the outside ambient air is thus carried out by said compressors. The compressors are electrically driven. As a variant, the creation of the air flow can be carried out using a turbine supplied with LPG or Kérozènen :.

  The next phase consists in the preparation of the one-dimensional flow at stable temperature and this by means of a primary air mixer (3). To this end, the four-stage high-pressure compressor, that is to say having four decreasing sections in successive diameter, or the turbine, is capable at the end of leading to a convergent (4) allowing the acceleration of the flow d high pressure air. Said converging nozzle (4) is suitably secured to the end of the high pressure compressor or the turbine. The convergent has a decreasing conical profile from upstream to downstream. Said convergent is arranged in the middle part to receive two pipes (5) and (6) emerging inside the latter to allow the addition of ambient air or hot air by a specific low pressure vortex called hot -cold. Proportional linear solenoid valves (7) integrated in the convergent in the axial direction make it possible to regulate the flows and their characteristics. The converging point (4) has, at the downstream end, a neck (8) at the end of which a diverging point (10) is fixed, then defining the start of the secondary circuit. At the neck of the divergent, the one-dimensional flow, previously generated, is stable, at a stable temperature which is positive, and this to avoid possible condensation problems.

  The pipes (5) and (6) allow the addition of hot air and ambient air into the convergent (4) and are suitably established in the installation. Obtaining hot air at a determined temperature is achieved by introducing into the tubing concerned, after the removal of outside air, an integrated heating means of a type known to those skilled in the art.

  At the neck (9) of the convergent (4), the speed of the flow is (V1) and the pressure (P1). At the outlet and downstream of the convergent, there is therefore arranged the divergent (10) which opens into a secondary air mixer (1) 15 with a one-dimensional flow stabilization chamber in temperature and pressure. This secondary air mixer thus receives the stabilizing base (12) in primary air temperature, decreasing the speed (V1) in speed (V2) by the divergent in order to increase its pressure (P1) in pressure (P2), by slightly lowering its temperature to stabilize this flow on this new pressure (P2) and a new temperature. In this phase, the speed (V2) is lower than (V1) and the pressure (P2) higher than (P1) at the divergent level. Said secondary air mixer (11) includes in the stabilization chamber (12) a primary vortex (13) and, at the end of said chamber, a convergent (14) which has the purpose of directing and narrowing the new flow created by the primary vortex to orient it downstream in an isobaric layer vortex (15).

  The primary vortex (13) has the function of transforming the flow in the linear initial state into a flow in the centrifugation state both linear and orbital. The new air flow thus created remains stabilized in temperature and pressure.

  The primary vortex (13) has a cylindrical configuration being held appropriately and fixedly in the stabilization chamber using any connecting means. The primary vortex is designed with a structure comprising passages or zones (13a) for circulation of air through solid parts (13b) of thickness, these circulation zones generating a circulation effect in a helix. The primary vortex (13) comprises a peripheral contour (13c) allowing the creation of air and radially a plurality of circulation zones (13a) arranged in a helix and converging towards the open central part (13d) of said primary vortex. The particular profile of the circulation zones is established curvilinear (13e) to give an effect of acceleration and guidance of the flow, and this at constant temperature. The primary vortex includes, at the end of the air circulation zones, specific parts (13f) created by calculating speed triangles to accelerate the flow. The primary vortex (13) thus creates a vortex, linear and orbital movement of the flow. There is thus shown in Figures S and 6 said primary vortex (13). The air flow is thus modulated. At this instant, the air flow is both linear and orbital vortex at a stable temperature. The pressure (P2) can be variable and adapted according to the primary air obtained in the initial phase. 25 -2 Second phase: ll We now describe the next phase consisting in the creation of a static pressure (P3) independent of atmospheric pressure and we refer to Figure 7.

  The isobaric layer vortex (15) is located in line with and the extension of a secondary air mixer (11) at the end of the convergent (14) provided behind the stabilization chamber (12). The function of the isobaric layer vortex (15) is to create a stabilized static pressure of the air flow passing through it. It consists of an Archimedes screw 10 with variable pitch. In particular, said Archimedes screw comprises several zones of variable pitch and successively a first zone of progressive variable pitch (15a), then a middle zone of declining pitch (15b) then a final zone of progressive pitch (15c). The vortex air, coming from the secondary mixer (11), is therefore brought through, in part, the Archimedes screw (15) whose diameter is less than the outlet diameter of the convergent (14) of the secondary mixer ( 11).

  The variable pitch of said Archimedes screw is determined after calculation 20 as a function of the annual average of the different isobaric layers indicated by METEO FRANCE, on a scale from 0 to 4000 meters above sea level. This scale is divided into a layer limited to 100 meters to be able to create the adiabatic curve. The Archimedes screw (15) is in a fixed position. It is maintained in any suitable manner with respect to the structure-frame of the installation including a secondary casing (17) concentric with the external fairing (C).

  During the passage of the vortex air, at a certain moment, the centrifugation of the air flow escapes the control of the Archimedes screw (15) creating a volute (18) divergent going from the negative level (N-) to positive level (N +) of the pressure zone (figure 7). From this instant, a stabilized flow rate, temperature and pressure (P3) are noted.

  The pressure zone (P3) is constantly checked using temperature, hygrometry, pressure and speed sensors (19). The 10 sensors are arranged around the receiving area of the Archimedes screw (15), being fixed in any suitable manner. These sensors can move on a guide surface (19a), parallel to the Archimedes screw and allowing the measurements.

  In the event that an isobaric layer increases or decreases, the sensors (19) concerned would regulate the prior solenoid valves (7) in order to modify the parameters of the primary air flow.

  The various sensors (19) are connected to an integrated management system 20 ensuring constant readings and at determined intervals which can be of the order of 50 milliseconds.

  Thus the air coming from the primary vortex (13) is subjected, by means of the Archimedes' screw (15), to a new acceleration until the birth of the volute (18). The linear and orbital one-dimensional flow, at this instant, is stable in temperature, speed and pressure.

  -3- Third phase: It is now necessary to describe the third operational phase of the process which consists of the means allowing the manufacture of a core 5 of ice support from the snowflake to be obtained. For this we refer to Figures 8 to 12.

  This phase involves a double action, on the one hand an action on the flow to create a phenomenon of vortex and pulsating depression, and on the other hand the creation of the support core. For this purpose, at the outlet of the isobaric layer vortex (15), with Archimedes' screw, there is located in the axial extension a secondary low pressure vortex (16). The purpose of this is to transform the one-dimensional air flow of helical centrifugation arriving around the geometric axis (XX) into an air flow forming a helical spiral rotating around the geometric axis (ZZ) in order to create a vortex and pulsating geographic area. For this, from the Lporta '' structure '' are provided blades (20) and (21) p / rofiles, arranged in a circle and concentric. The first stage of blades (20) relates to low pressures, and the upper circle surrounding the first series of blades (20) provides another series of blades (21) in high pressure intervention for pulsating fields. The attachment of the blades to the built structure is established in any suitable manner. The profile of the blades (20) and (21) is identical to the two stages with a curved central part (20a) and (21a) extending on either side by two panels (20b and 20c), (2 lb 25 and 2 lc) curvilinear oriented in opposite directions giving a propeller effect. The configuration of said blades (20 and 21) is established to allow the flow of the flow and the transformation of its movement from the axis (X-X) to the axis (Z-Z). The blades (20 and 21) are fixedly arranged inside a convergent (22).

  Around the secondary low pressure vortex (16), a secondary air mixer and saturation base is provided. This mixer has the function of creating a thermal shock by the meeting of the air flow in the form of a pulsating swirling field with the addition of air saturated with 95% of water droplets for the production of the ice support nuclei.

  More particularly, a manifold (24) for supplying air saturated with droplets is disposed around the low pressure secondary vortex (16), and conduits (25) open into said convergent (22) downstream of the two staged rows of blades. (20 and 21).

  The temperature of the air flow coming from the vortex isobaric layers is positive, while the temperature of the saturated air coming from the feeder (2A) is negative while being in depression. The size of the droplets is defined by the passage through a calibrated filter (not shown) which can be adjusted constantly. The thermal shock in the meeting of the pulsating swirling fields and the air saturated with 95% of the water droplets, will cause the production of the ice nuclei which will be entrained in the center of the swirling fields due to the inequality of the internal pressures .

  Downstream of the low pressure secondary vortex (16), the high pressure secondary vortex (26) is arranged. It also consists of two rows of profiled fixed blades (27 - 28) arranged in a stepped and concentric circle, the blades having profiles identical to those of the low pressure secondary vortex. Said blades (27 - 28) are located inside a convergent (29) and are secured and fixed, in any suitable manner, to the latter. The high pressure secondary vortex velocity triangles (26) cause the ice cores to centrifuge in the vortex fields thus placing them in the zone of controlled static pressure. The high pressure secondary vortex (26) redirects the air flow established around the geometric axis (Z-Z) into a constant cylindrical air flow along the axis (X-X). Thus, the ice support core passes through a stable cylindrical field. FIG. 12 shows the circulation curves of the vortex flow in contact with the blades of the high pressure secondary vortex.

  -4- Fourth phase: The next phase consists in the manufacture of the snowflake, according to Figures 13 to 15 and 19.

  The deflection of the vortex fields by the different blades of the 20 secondary vortices at low and high pressures, will take place according to two linear air flows, at constant speed, corresponding to each stage of the blades of said vortices, but at pressures and at different temperatures. Thus, one will obtain a dissociation of the vortex fields and the ice cores so that they appear in front of the mixer (27) of the vortex fields with vacuum in front of the previous phase.

  When the eddy fields containing the ice cores flow through the vacuum mixers, the difference in density between the two air flows causes the eddy fields to burst, releasing the ice cores and a slight rise 5 temperature around them. A thin film of water will form on the periphery of each ice nucleus and thus prepare each support nucleus for the nucleation procedure.

  For this purpose, there is available, downstream of the secondary vortexes at low and high pressures, a supply source (28) of cold water vapor obtained by constant vacuuming of the cryogenic tank (29) containing the water of production. The cold water vapor obtained flows through a stream of air at -40 ° C. from said specific low pressure vortex creating a hot flow and a cold source inside the vacuum mixer, which causes needles to crystallize. vapor which are welded by heat exchange on the film of water coating the ice core. There is therefore fixing of said needles on each ice core considered and obtaining snowflakes. The quality and consistency of the snowflakes can be adjusted by automatically or not modifying the size of the cold water vapor filter introduced into the power source (23) and by increasing or decreasing the internal static pressure of the depression chamber. To this end, a divergent battery (33) is arranged downstream of the nucleation phase.

  These divergents are mounted in a star on a control cylinder (not shown), the cylinder of which is integral with the structure of the frame. This makes it possible to vary the stabilized pressure at the outlet of the snow cannon and therefore the size of the flake according to the arrow (F). All the snowflakes thus produced can then be transported in the gas stream of the one-dimensional flow and then evacuated.

  -5- Fifth phase: The transport of the snowflakes thus produced is carried out by the installation downstream of the installation of a low pressure diffuser (30) and a high pressure diffuser (31) and the expulsion of the flakes, results in pressure exchange of the high pressure and low pressure air flows. The high pressure diffuser (31) operates at low speed and is located on the periphery of the two air flows. Its role is to cool the high pressure flow retaining the snowflakes and to constitute a gas stream protected by the cold tunnel (32) coming from the initial low pressure compressor. The cold air tunnel expels pressure at such a speed that it cannot change direction despite external side winds. The snowflakes centered from the high pressure diffuser are therefore properly projected outside.

  The advantages of the process and the installation are numerous. 20 First of all, the concept developed by the installation, which is to make snow from and in an open, self-contained enclosure independent of the external environment and its constraints, makes it possible to manufacture snowflakes at a temperature independent of the outside temperature.

  The open autonomous enclosure is established with a given specificity of pressure, temperature and completely frees itself from the external environment.

  The principle of this innovation is considerable because we reproduce, in the open autonomous enclosure, the climatic conditions at high altitude.

  The quality of the snow is improved for the following reasons: the fact of manufacturing an ice support core on which the frozen needles are then fixed allows a thermal exchange between them and a longer durability of the flakes; - the density of the snowflakes can be varied by acting on the 15 phases of the process; - the selection of flakes, according to their characteristics, can be a favorable element to take into account the external environment for the implementation of each installation.

  Longer life is achieved because the snowflakes are free from dirt and particles that are usually found in the outside air.

  The volume of the installation is unimportant since it is approximately 25 2 meters 70 in length or 3 meters 50 with the motorization assembly. The inlet diameter of the installation is approximately 1 meter and the outlet, at the level of the diffuser, of the order of 1 meter 50. The cryogenic tank containing water at a temperature of - 1 to 2 C is under vacuum, so there is no gel. The installation is compact and efficient.

  Economically and environmentally, the amount of water required for the production of snow according to the invention is reduced and is divided by three.

  The snow gun management interface can be connected to a computer interface with simplified management. The flake transport system compared to a conventional expulsion allows the projection of the flakes over distances ranging from 5 to 10 times the distances obtained according to the prior art.

  The nucleation made inside the autonomous enclosure allows the manufacture of a real snowflake perfectly controlled unlike the grains of ice obtained according to the prior art, the nucleation taking place outside of a difficult way to master.

  Another advantage is that all of the internal components of this gun are in a fixed position in a frame structure, with the exception of the diverging battery located after nucleation, and the compressor.

  The structure-frame is made of traditional design boilermaking.

Claims (19)

  -1- Process for manufacturing artificial snow, characterized in that it consists in reproducing in situ in an open autonomous enclosure which is freed from the external climatic conditions of artificial snow, by reproducing the conditions for making snow in high atmosphere, and in that it implements the following phases: creation of a one-dimensional flow at a temperature independent of the outside temperature and transformation of the linear air flow into a vortex flow, - creation of a static pressure independent of atmospheric pressure, - manufacture of an ice support core of the snowflake to be obtained, - creation of the snowflake by nucleation, - evacuation of the flakes in an external medium, transported by the stable gas stream of the one-dimensional flow.   -2- Method according to claim 1, characterized in that: - a stable one-dimensional flow is created which is worked to be addressed in an isobaric vortex for its transformation into a flow in the state of linear and orbital centrifugation stabilized in temperature and in pressure, - a static pressure independent of atmospheric pressure is created, with an acceleration of the speed of the flow, - the flow generated is subjected to a phenomenon of vortex and pulsating depression with a modification of its geometric axis starting from an axis (XX) to an axis (ZZ), - we proceed to the manufacture of the ice support core by introducing air saturated with 95% water droplets and by creating a thermal shock in the meets pulsating vortex fields and 95% saturated air, - we proceed to the positioning of the ice cores in the vortex fields in the static pressure zone, - we proceed repositioning the air flow along the axis (XX) in a cylindrical field, - we proceed to dissociate the vortex fields of the 10 ice support cores by causing a temperature increase causing a film of water to appear on each core of ice, - cold water vapor is introduced through a supply source causing this vapor to crystallize into needles, said needles being welded by thermal exchanges on the film of water coating each core of ice allowing the obtaining snowflakes, - the snowflakes are evacuated outside, transported by the stable gas stream of the one-dimensional flow.   -3- Installation for the manufacture of artificial snow implementing the method according to any one of claims 1 and 2, characterized in that it comprises inside an open autonomous enclosure arranged in situ in a place for producing artificial snow: - means for creating a one-dimensional flow at a temperature independent of the outside temperature, and the transformation of the linear flow into a vortex flow, - means allowing the creation of a static pressure independent of atmospheric pressure , - means allowing the manufacture of an ice support core of the snowflake to be obtained, - means allowing the creation of the snowflake by nucleation, - means allowing the evacuation of snowflakes in an external environment.   -4- Installation according to claim 3, characterized in that the different means are incorporated in an open autonomous enclosure having a single outer fairing, said enclosure being disposed above or near a cryogenic tank with a plate allowing the supply in water in certain phases of the process.   -5- Installation according to claims 3 and 4, characterized in that the means allowing the creation of the one-dimensional flow consist of a low pressure compressor (1) with turbine (la) disposed upstream of the installation and surrounding a compressor high pressure (2), and in that the high pressure compressor is stepped with decreasing sections to lead to a convergent (4) allowing the acceleration of the flow of high pressure air, said convergent having end a neck (8) on which is disposed a divergent (1 0) defining the start of the secondary circuit.   -6- Installation according to claim 5, characterized in that the converging (4) is arranged in its middle part to receive two pipes (5) and (6) through which allow the addition of ambient air or hot air, and in that solenoid valves (7) are integrated in the convergent in the axial direction to allow flow regulation.   -7- Installation according to claim 6, characterized in that the divergent (10) opens into a secondary air mixer (11) comprising a chamber (12) for stabilizing the one-dimensional flow and including a primary vortex (13), and in that the mixer (11) has at the end a convergent 5 (14) narrowing the flow created by the primary vortex to orient it downstream in a vortex isobaric layers (15).   -8- Installation according to claim 7, characterized in that the primary vortex is designed from a cylindrical structure comprising 10 passages (13a) for air circulation through thick parts (13b) full and generating a helical circulation effect, said vortex (13) comprising a peripheral contour (13c) and an open central part (13d), the circulation zones (13a) going from one to the other and having a curvilinear profile ( 13e) to give an acceleration and guidance effect 15 of flow at constant temperature, and in that the circulation zones have specific parts created by the calculation of speed triangles (13f), said primary vortex creating a vortex movement linear and orbital flow.   -9- Installation according to claim 7, characterized in that the vortex isobaric layers (15) in alignment and extension of the secondary air mixer has the function of creating a stabilized static pressure of the air flow which passes through it , said vortex being constituted by an Archimedes screw with variable pitch.   -10- Installation according to claim 9, characterized in that the Archimedes screw comprises a first zone with progressive variable pitch (15a), then a middle zone with decreasing pitch (15b), then a final zone with progressive pitch (15c) ).   -11- Installation according to claim 9, characterized in that sensors 5 (19) of hygrometry temperature, pressure and speed are arranged around the Archimedes screw (15), and are mounted on guide surfaces parallel to said Archimedes screw.   -12- Installation according to claim 7, characterized in that at the outlet of the isobaric layer vortex 10 is arranged a low pressure secondary vortex (16) having the function of transforming the one-dimensional air flow of helical centrifugation arriving on the axis (XX) in a spiral rotating around the axis (ZZ) to create a swirling and pulsating effect.   -13- Installation according to claim 12, characterized in that the low pressure secondary vortex comprises two stages of fixed blades (20) and (21) profiled arranged in a circle and concentric, the first blade stage (20) relating to low pressures , and the upper circle the high pressures, and in that the profile of the blades is established with a curvilinear central part 20 extending on either side by curvilinear panels oriented in opposite directions giving a helical effect, and in that the configuration of the blades allows the transformation of the movement from the axis (XX) to the axis (ZZ).   -14- Installation according to claim 12, characterized in that around the secondary low pressure vortex (16) is disposed a secondary air mixer and saturation base (22) having the function of creating a thermal shock by the encounter of an air flow in the form of pulsating swirling fields with the addition of air saturated with 95% of droplets for the production of ice support nuclei.   -15- Installation according to claim 14, characterized in that it 5 comprises a manifold (24) for supplying saturated air disposed around the low pressure secondary vortex (16), and in that conduits (25) open out in a convergent surrounding the blades (20) and (21) of the low pressure secondary vortex.   -16- Installation according to claim 12, characterized in that downstream of the low pressure secondary vortex is disposed a high pressure secondary vortex (26) consisting of two rows of fixed blades (27) and (28) arranged in staggered circles and concentric, said high pressure secondary vortex redirecting the air flow established around the axis (ZZ) into an air flow around the axis (XX).   -17- Installation according to claim 6, characterized in that the pal-es of the secondary vortices at low and high pressure cause the deflection of the vortex fields at different pressures and temperatures for 20 dissociation with the ice cores obtained, and l 'obtaining a film of water around each ice core, and in that downstream of the secondary vortices at low and high pressure is arranged a supply source (23) of cold water vapor obtained by placing under vacuum in the cryogenic tank, said cold water vapor causing crystallization into needles during its transfer to coat each core of ice in order to obtain snowflakes.   -18- Installation according to claim 17, characterized in that it comprises a diverging battery (33) disposed downstream of the nucleation phase.   -19- Installation according to claim 18, characterized in that it comprises a low pressure diffuser (30) and a high pressure diffuser (31) allowing the expulsion to the outside of said snowflakes.