CZ2010594A3 - Process for producing artificial snow and apparatus for making the same - Google Patents

Abstract

In the process of producing technical snow (7) by spraying water or water in the air stream with a snow gun (1, 2, 2 ') on the impact surface (3), between at least one snow gun (1, 2, 2') and the impact surface (3) create at least one impact zone (4) into which the individual water jets (5, 5 ') and / or water droplets entrained in the air stream and / or water mist droplets (6) are directed so as to strike each other and / or a rigid obstacle, and then, in the path between the impact area (4) and the impact surface (3), crystallize in its entirety and form technical snow (7) incident on the impact surface (3) in a fully crystallized state. The snow making device (7) comprises a tubular snow gun (1) with a fan (8) and nozzles (9) provided with a directional extension (10) or a directional orifice (11) for directing the exit to the impact zone (4). The snow making device (7) may also comprise a tubular snow gun (1) or a rod snow gun (2, 2 ') provided with a non-wettable screen (12). The impact area (4) can also be formed by directing the water stream (5, 5 ') from two rod-shaped snow deltas (2, 2') against each other.

Description

Method of production of technical snow and equipment for carrying out this method

Field of technology

The invention relates to a method for producing technical snow and to an apparatus for producing technical snow, in particular for downhill or cross-country skiing and other winter sports.

State of the art

Technical snow is produced by spraying water from the nozzles of the device, which is known as the "snow cannon". Tiny droplets freeze in the surrounding air, the temperature of which must be below freezing and fall to the ground like ice crystals. The formation of crystals is positively affected by the ambient temperature, the colder the ambient air, the more efficient the cannon.

Currently, there are two main groups of snow cannons for the production of technical snow: a bar snow cannon, also referred to as a shower due to the principle of its function and appearance, where water is sprayed by small nozzles into the cold ambient air. The second type of snow cannon is a tube cannon with nozzles and a fan that blows water drops from the nozzles into the surrounding air. The fan creates a stream of air that carries the droplets long enough to freeze before they hit the ground. This feature allows the mobility of this type of cannon, which is limited only by the length of the water supply hose and the length of the cable supplying electrical energy to the fan motor.

The snow cannon system is characterized by the use of snow cannon nozzles on a stable pole 6 to 11 meters high. The water pressure in the water distribution network around the snow-covered area with a pressure of 10 to 90 bar is used. The disadvantage of this type of works is their stable location, where their proper function depends, among other things, on the direction and speed of the wind, which can blow the produced snow out of the required area. Its advantage is that it does not need a power supply for the fan.

In a system of tubular snow cannons with a fan and nozzles, water is supplied via a pipe from the water supply network around the snow-covered area with connection points with a pressure of 8 to 50 bar. The snow cannon has a cylindrical shape with a relatively large diameter (approx. 50 cm) and inside the cylindrical body there is a fan driven by an electric motor, which sucks in air and blows it out at high speed. A large number of water nozzles are housed in the mouth, which is injected into the air stream formed by the fan, which carries them long enough for them to freeze. The disadvantage of this type of snow cannon is the need for electrical energy to drive the fan. The advantage of this type of snow cannon is its mobility.

The disadvantage of both types of snow cannons is their low efficiency.

The efficiency of the types of snow cannons described above reduces the physical properties of the water, which allows it to be subcooled. In nature, under normal conditions, the water contained in the cloud spontaneously crystallizes at a temperature of about - 15 ° C. In practice, however, it is necessary to produce quality technical snow at much higher temperatures up to around 0 ° C. At these temperatures, however, uncrystallized droplets of subcooled water flow away in liquid form, or crystallize only after impact with the ground and form a layer of ice, which is dangerous because the ice is much harder than suffocated snow, and athletes fall and injure in these places. . The behavior of subcooled water after impact on the ground depends on the ambient temperature.

All of the following patents deal with increasing the efficiency of known snow cannons by forming nuclei.

WO01 / 86216 discloses an improvement of the basic type of bar cannon. It uses a turbine that sucks and compresses the ambient air, which is blown into an outlet orifice equipped with nozzles spraying pressurized water into the expanding air, which is cooled by expansion, which allows the production of technical snow even at ambient air temperatures above 0 ° C. The disadvantage of this solution is the need to supply compressed air. The disadvantage may also be the design complexity and price.

WO96 / 09505 describes the principle of producing technical snow using two types of nozzles. External, high-pressure nozzles create a special microclimate rich in crystallization nuclei, to which droplets dispersed from the internal nozzles are attached (frozen). The disadvantage of this solution is that it is not guaranteed that the entire mass of blown water mist will mix with the crystallization cores that surround it. Mixing the water droplet stream in the water mist with the crystallization cores is fundamentally important to increase the efficiency of the snow cannon. The disadvantage of this solution may also be the design complexity and demands on materials resistant to high pressure and low temperature.

WO97 / 26493 discloses nozzles and their location angles relative to the longitudinal axis of the air flowing from a fan in WO96 / 09505.

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WO2009 / 018319 describes the principle of the production of technical snow, in which crystallization cores formed by the expansion of a pre-compressed air-water mixture in special nozzles are injected into the air stream. Drops blown into the air stream at the end of a snow cannon tube from conventional nozzles freeze on these crystallization cores. Special nozzles for the production of crystallization cores are located at the outlet side of the cannon tube in the middle of the fan-driven air stream, which is at the inlet edge of the cannon tube.

WO2009 / 125359 uses special nozzles located at the exit edge of a snow cannon tube to create crystallization cores. These nozzles are located on the same ring of the supply pipe as the nozzles spraying water into the air stream driven by the fan located on the inlet side of the snow cannon.

WO95 / 04906 describes a method for producing technical snow using a snow cannon with a fan, which contains two types of nozzles. At the exit edge of the conical snow cannon body are nozzles which spray water into the air stream drawn in by a fan located on the inlet side of the cannon, enriched with crystallization cores formed by high pressure nozzles located in the middle of the snow cannon body.

The disadvantage of all three of the above solutions is the design complexity of the nozzles for the crystallization cores and their material complexity. Another disadvantage may be the requirement for a high quality of purity of the water supplied to the nozzles for the crystallization cores, because their diameter is smaller and the impurities contained in the water could clog or even destroy them. Achieving the required water quality is difficult to control the filters and their maintenance.

WO2008 / 075689 deals with the subcooling of supply air which is sucked in by a snow cannon fan and then water is sprayed into it, which freezes and forms artificial snow. The disadvantage of this solution is the need for a device for subcooling the air that is fed to the cannon

In the solutions known from the prior art, the problem of water subcooling in the production of technical snow is solved by the production of crystallization cores by compression and subsequent air expansion, where the expansion cools the air, in which the crystallization nuclei necessary for snowflake formation are more easily formed.

The aim of all the above methods and devices for increasing the efficiency of snow cannons is the production of crystallization cores and thus increasing the efficiency of snow cannons. In the described patents, the problem is solved by lowering the temperature of the air in which the crystallization nuclei are formed. A common disadvantage of the prior art solutions is that, while they improve the efficiency of snow cannons to some extent, they are structurally complex, costly, and do not eliminate the problem of ice formation around the snow cannons.

The object of the invention is to provide a method for producing technical snow and a device for carrying out this method, which would eliminate the above-mentioned drawbacks, be structurally simpler and cheaper to invest and prevent the formation of ice surfaces around snow cannons. at -15 ° C.

The essence of the invention

The disadvantages of the above-described methods and apparatus for producing technical snow are largely eliminated by the method for producing technical snow and the apparatus for carrying out this method according to the present invention.

The present invention addresses the problem of crystallization of water droplets in a different physical way than the known solutions. In known solutions, the problem of crystallization is solved by lowering the temperature of the air in which the crystallization nuclei are formed. In the solution according to the invention, the heat of the subcooled water is removed by mechanical movement.

The solution according to the invention uses the physical properties of the instability of subcooled water, where only a small movement of water in a given volume is enough to induce spontaneous crystallization.

The movement inside the water droplets is ensured by directing all the droplets leaving the snow cannon to one place at a certain distance from the exit mouth of the cannon, where the droplets collide with each other. The impact causes a movement in a given volume, which removes a sufficient amount of internal energy and starts the process of spontaneous crystallization. The invention relates, on the one hand, to a method for producing technical snow by a snow cannon, the essence of which consists in creating at least one impact area between the mouth of the snow cannon and the impact surface, into which the individual water streams and / or water droplets are entrained in the air stream and / or droplets of water mist supplied in the subcooled state, and are directed so as to strike each other and / or against a solid obstacle, thus depriving them of their internal energy, which keeps them in a liquid state, as they hold the atoms in the lattice far enough to the water remained liquid. The movement of the liquid in a given volume releases this energy, and since the temperature of the water in the drop is lower than 0 ° C, a crystallization process starts, which releases excess heat, heating the drop and dissipating the heat of crystallization to the surroundings. and the drop properly /.crystallizes and falls to the ground like a snowflake. In this way, water droplets in the path between the impact area and the impact surface crystallize in their entire volume and form technical snow falling on the impact area in a fully crystallized state. At the same time, the drop does not lose excess heat until it hits the ground, where it / crystallizes, together with other drops, into ice (ice plates) or drains because the ambient temperature is so high (even below freezing). that the heat released by crystallization is so great that the temperature of the water / drop rises above zero and the drop does not freeze, which is a disadvantage of all known methods of producing technical snow and snow cannons for its production.

In a preferred embodiment of the method according to the invention, directing the flow of water droplets in the air stream or water mist droplets emerging from the mouth of the tubular snow cannon provided with fan and nozzles into the impact area is Thanks to this solution, there is no need to produce new snow cannons, the extensions are simply deployed on existing cannons, which will significantly save investment funds for owners of ski slopes and other winter sports facilities where it is necessary to snow with technical snow.

In a further preferred embodiment of the method according to the invention, the outlets of the at least two rod snow cannons are oriented in such a way that the water jets resp. water drops emerging from them collide in the impact area. This solution also uses existing snowmaking equipment, without the need to invest in new types of snow cannons.

Finally, a method of producing technical snow according to the invention is advantageous, in which a solid barrier formed by a non-wetting sieve is arranged in the impact area. This solution can be used for both of the above types of works, ie. both for the snow cannon tube with a fan and for the cannon rods.

The invention further relates to a device for the production of technical snow, using a rod snow cannon or a tube snow cannon with a fan and nozzles, the essence of which consists in that at least one snow cannon is provided with means for creating an impact area for impinging individual water streams and / or water droplets entrained in the air stream and / or water droplets into each other or on a solid obstacle, the impact area lying between the mouth of the snow cannon and the impact surface. This ensures that the heat of crystallization is removed by water droplets, which then fall to the ground as.

• · ··· ·· ·· ··· ·· ice crystals. This achieves the creation of quality technical snow, which can be easily handled, such as moving it to less snowy places, where it is not possible for technical reasons to install snow cannons, or storing it in piles in a suitable place.

In a preferred embodiment of the device according to the invention, the impact area means is formed by a baffle mounted on the mouth of a tubular snow cannon provided with a fan and nozzles, the baffle having a conical shape and a convex body in the central area for directing water mist from the center of the snow cannon the walls of the routing attachment. The droplet flow rectifying attachment is very simple in construction and undemanding in terms of material. The main advantage of the attachment is that it is also applicable to existing tubular snow cannons with a fan.

In another preferred embodiment of the device according to the invention, the means for creating an impact area in a tubular snow cannon provided with a fan and nozzles is formed by a directional mouth with at least two directional slots. The directional mouth is equipped with a reflecting body for directing water mist into the directional slits. The directional slits can furthermore advantageously be provided with movable flaps which allow the individual streams of water droplets entrained in the air stream and / or water mist droplets to be directed into the impact area at a variable distance from the snow cannon mouth, depending on the ambient air temperature. The directional mouth can also be used on existing snow cannons with a fan.

In this way, the distance of the impact area from the mouth can be adjusted depending on the ambient air temperature.

It is advantageous that the directional attachment or the directional orifice are provided on their inner walls with guide grooves for the directional guidance of the water droplets in the air or water mist stream. This will refine the direction of their flight path and more accurately reach the impact area, which is therefore smaller. This prevents water droplets from dispersing, which could cause them not to collide with each other.

In another preferred embodiment of the device according to the invention, the means for forming the impact area is formed by at least one non-wetting sieve arranged between the mouth of the tube or rod snow cannon and the impact surface.

Ί

In another preferred embodiment of the device according to the invention, the means for forming the impact area is formed by a set of at least two rod snow cannons, the outlets of which are oriented so that the water streams emerging from each other collide in the impact area.

The advantages of the solution according to the invention are that it significantly improves the efficiency of existing snow cannons of all types, improves the quality of technical snow, and does not represent an increase in the cost of producing technical snow for owners and operators of winter sports facilities. It is particularly advantageous that no ice sheets are formed in the vicinity of the snow cannons, which means an increase in traffic safety on the slopes, and technical snow can be handled well, including the possibility of storing it in piles.

Overview of reference marks in the drawings

The invention will be further elucidated with the aid of the drawings, in which FIG. Fig. 3 is a side view of the directional attachment, Fig. 4 is a rear view of the directional attachment, Fig. 5 is a rear view of the directional mouth itself for a tubular snow cannon provided with two rectangular directional slots provided with directional flaps; view of the directional mouth, Fig. 8 detail of the directional flap, Fig. 9 side view of two rod snow cannons on a common pole, with outlets directed to the impact area, Fig. 10 rear view of the rod snow cannons of Fig. 9, Fig. 11 side view of a snow snow cannon with a non-wetting sieve, Fig. 12 rear view of a snow snow cannon with a non-wetting sieve, Fig. 13 plan view of a non-wetting sieve with a supporting structure, Fig. 14 side view of a non-wetting sieve with supporting structure.

Examples of embodiments of the invention

It is to be understood that the specific embodiments of the invention described and illustrated below are presented by way of illustration and not by way of limitation. Those skilled in the art will find, or be able to ascertain using routine experimentation, a greater or lesser number of equivalents to the specific embodiments of the invention specifically described herein. These equivalents will also be included within the scope of the following claims.

Example 1

Fig. 1 and Fig. 2 show a conventional tubular snow cannon 1 with a fan 8 on the air supply side 18 and with nozzles 9 arranged in a circle around the inner circumference of the mouth. A water supply 19 is fed to the nozzles 9. At the mouth of the tubular snow cannon 1, a guide attachment 10, made of sheet metal or plastic, is mounted. The guide attachment 10 connects to the cylindrical mouth of the tubular snow cannon 1, is hollow and tapers conically away from the mouth of the snow cannon L. The central area of the guide nozzle 10 is filled by a reflecting body 15, which is also made of sheet metal or plastic and bodies, in this case an ellipsoid. The reflector body 15 is fixed to the housing of the baffle attachment 10 by means of four reinforcements 20. Its convex ellipsoidal surface is oriented against the mouth of the snow cannon 1, from which water mist droplets 6 emerge. cross-section, but on impact with the convex surface of the reflector 15 forms a cross-sectional shape, and is guided between the housing of the baffle 10 and the surface of the baffle 15 with guide grooves 17 to exit the baffle 10. due to the conical shape of the baffle 10, the diameter of the intermediate ring gradually decreases until the water mist 6 or water droplets in the air stream collide in the impact area 4, where they collide with each other. In the impact area 4, the internal energy of the water droplets colliding with each other decreases and crystallization begins, accompanied by the development of heat. Subsequently, on the route between the impact area 4 and the impact surface 3, the drops are further cooled, so that they fall on the impact surface 3 as high-quality technical snow 7 in a fully crystallized state.

In another exemplary embodiment, not shown, a non-wetting sieve 12 can be fastened in front of the tubular snow cannon 1, which creates a fixed obstacle in the impact area 4, where a similar effect occurs as when water drops hit each other.

Example 2

The tubular snow cannon which is described in the first example and shown in FIG.

The directional mouth 11 has a similar function as the directional attachment 10, but does not have a conical shape, but a circular shape, on the side which connects to the snow cannon 1 with the fan 8 and nozzles 9 and has opposite directional slots 13, 13 on the outlet side. A reflecting body 15 which directs water mist 6 or water droplets in the air stream into two directional slits 13, 13 'of rectangular cross-section which are chamfered at such an angle that the outlets of the water mist 6 or water droplets in the air stream emerging from the directional slits 13, 13 ', met in the impact area 4, where they collide with each other. The process of crystallization of technical snow 7 before impact on the impact surface 3 is the same as in Example 1. In order to easily control the distance of the impact area 4 from the snow cannon 1, the directional slots 13, 13 'are provided with directional flaps 14, 14 / which are rotatable. mounted on the hinges 22 and provided with adjusting screws 23, by means of which the angular adjustment of the directional flaps 14, 14 'and thus the distance of the impact area 4 can be regulated.

Example 3

Fig. 9 and Fig. 10 show another example of the production of technical snow 7, using two snow plow rods 2, 2 ', the arms of which are mounted on a common support column 24, which is advantageous in terms of a common water supply. The heads with the nozzles of the snow cannons 2, 2 'are set so that the water streams 5, 5' resp. water droplets collide with each other in the impact area 4, which lies substantially above the impact surface 3. In the impact area, the internal energy of the water droplets colliding with each other decreases and crystallization begins, accompanied by heat generation. Subsequently, on the route between the impact area 4 and the impact surface 3, the drops are further cooled, and they fall on the impact surface 3 as finished technical snow 7 with full properties.

Example 4

In this exemplary embodiment, FIGS. 11 to 14 show the use of a fixed obstacle in the impact area 4 to reduce the internal energy of the water droplets. A fixed obstacle here is formed by the non-wetting sieve 12 mounted in front of the mouth of the bar snow cannon 2. As already mentioned in the first example, the non-wetting sieve 12 can similarly be mounted in front of the tubular snow cannon 1. The non-wetting screen 12, preferably made of plastic or coated metal, is fastened to the pole snow cannon 2 in a position between the head of the pole snow cannon 2 with nozzles and the impact surface by means of a three-arm support structure 25 with upper sleeve 26 and lower sleeve 26 '. 3. Water flow 5 resp. drops of water hit the sieve and spray on the individual eyes. The internal energy of the individual droplets does not decrease here due to the impact of the water droplets on each other, but first due to the impact on a solid obstacle, here on the non-wetting sieve 12. The crystallization process is similar to the previous examples. that after the reduction of the internal energy due to the movement of water in the volume of the given drop, crystallization starts with heat generation, and on the path between the impact area 4 and the impact surface 3 the drops further cool and fall on the impact surface 3 like technical snow 7 its volume. It is clear that a solid barrier may be formed by devices other than the non-wetting sieve 12.

Industrial applicability

The method of producing technical snow and the device for carrying out this method according to the invention can be used for the production of technical (artificial) snow on areas for winter sports, such as skiing, snowboarding, sledding, etc., and wherever it is necessary to create technical snow with properties close to natural snow.

Claims (11)

PATENT CLAIMS A method of producing technical snow (7) by spraying water or water in an air stream by means of a snow cannon (1, 2, 2 ') onto the impact surface (3), characterized in that between the mouth of the at least one snow cannon (1, 2, 2 ') and at least one impact area (4) is formed by the impact surface (3), into which the individual water streams (5, 5') and / or water droplets entrained in the air stream and / or water mist droplets (6) are formed. ) are directed so that they collide with each other and / or against a solid obstacle, reducing their internal energy, and subsequently crystallize in their entirety on the route between the impact area (4) and the impact surface (3) and form technical snow (7). ) incident on the impact surface (3) in a fully crystallized state. Method for producing technical snow according to claim 1, characterized in that the current exiting the mouth of the tubular snow cannon (1) provided with the fan (8) and nozzles (9) to the impact area (4) is directed by means of a directing attachment (10). arranged at the mouth of the snow cannon (1), or by means of the directional mouth (11) of the snow cannon (1). Method for producing technical snow according to claim 1, characterized in that the outlets of the at least two bar snow cannons (2, 2 ') are oriented such that the water streams (5, 5) emerging from them meet in the impact area (4). . Method for producing technical snow according to claim 1, characterized in that the fixed obstacle in the impact area (4) is formed by a non-wetting sieve (12). Device for producing technical snow (7) by spraying water by means of a tubular snow cannon (1) provided with a fan (8) and nozzles (9) or by means of a rod snow cannon (2, 2 ') on the impact surface (3), characterized by that the at least one snow cannon (1, 2, 2) is provided with means for forming an impact area (4) for impinging individual water streams (5, 5 ') and / or water droplets entrained in the air stream and / or water mist droplets ( 6) into each other or on a fixed obstacle, the impact area (4) lying between the mouth of the snow cannon (1, 2, 2 ') and the impact surface (3). Device according to claim 5, characterized in that the means for forming the impact area (4) is formed by a guide attachment (10) arranged at the mouth of the snow cannon (1) provided with a fan (8) and nozzles (9), the guide attachment ( 10) has a conical shape and is provided in the central area with at least one reflecting body (15) for directing water mist (6) from the center of the snow cannon mouth (1) towards the walls of the directing attachment (10). Device according to claim 5, characterized in that the means for forming the impact area (4) is tubular at the snow cannon (1) provided with a fan (8) and nozzles (9) formed by a directional mouth (11) with at least two directional slots ( 13, 13 ') and a reflecting body (15) for directing water mist into the directional slits (13,13'). Device according to claim 7, characterized in that the directional slots (13, 13 ') are formed with the possibility of changing the angles of the water droplets in the air stream or water mist (6) from the directional mouth (11) of the snow cannon (1). Device according to at least one of Claims 6 to 8, characterized in that the directional extension (10) or the directional orifice (11) is provided on the walls of the reflector (15) with guide grooves (17) for directionally guiding water droplets in the air stream or water mist (6). Device according to claim 5, characterized in that the means for forming the impact area (4) is formed by at least one non-wetting screen (12) arranged between the mouth of the tubular snow cannon (1) or the bar snow cannon (2, 2 ') and impact area (3). Device according to claim 5, characterized in that the means for forming the impact area (4) is formed by a set of at least two rod snow cannons (2, 2 '), the outlets of which are oriented such that water jets (5, 5') or water droplets emerging from them collide with each other in the impact area (4).