How to make a snow gun with your own hands. How to make snow. Making snow is easy

Artificial snow is very popular in our time for shows, various holidays, events, weddings and anniversaries. It is used in performances as scenery, for decorating shop windows, and in the interior of bars and restaurants, snow will also find application. It does not stain clothes, is non-toxic, and looks exactly like the real thing.

How to make artificial snow with your own hands

Most importantly, you will need a liquid concentrate or a special powder. It is mainly produced by foreign manufacturers.

To make artificial snow with your own hands, you need to add ordinary water to this powder or concentrate, and after that it increases in volume by almost a hundred times. Such artificial snow is stored for several days. After the confluence of time, it begins to dry out and decrease in volume. If you collect it all and add water again, it will return to its previous state. Artificial snow is easily washed off and does not stain the surface.

snow cannon

It will be very easy to cover beautiful snowdrifts in just a few seconds. In order to get the effect of a blizzard or falling snow, an air gun and a special snow generator are used. The generator is a special device, the weight of which is from eleven to twenty kg. But there are installations for artificial snow of an even larger size - from forty kg. Such a snow generator works on a concentrate that is previously diluted with water. The concentrate is supplied from America, and it is certified. One liter of water is enough for an hour of operation of such an installation. The size and shape of snowflakes can be programmed in advance. The dispersion of snowflakes is up to fifteen meters.

Video: Comparative test of snow guns.

The price of a snow cannon is 150.000-1.000.000 rubles. The cost depends on its performance. They are mainly used for ski slopes. To begin with, it is better to buy the most inexpensive snow generator. It can also be rented out. The cost of rent per hour of work ranges from two to five thousand rubles.

In recent years, Europe has been quite warm even in winter. “There is no snow” - in the mountains this is no longer a joke, but the harsh truth of life. Because of this, starts are postponed, training camps are canceled, training is postponed. Moreover, “no snow” does not always mean that it really does not exist at all. It just doesn’t lie where it’s supposed to, or doesn’t cover the entire track, or even covers it, but it’s unsuitable for skiing - it’s too damp ... It happens that ski tournaments are held in a city park or in a square where there is never so much snow at all, how much is needed for this, and there have never been mountains: instead of slopes, an artificial track several floors high is being built, and real snow can lie on it - just not local.

We had a similar experience: they brought snow from Siberia, 4,000 kilometers by car, ”says Ekaterina Selyametova, president of the New League sports directorate, to RR. - We agreed with the management of local ski slopes, they willingly met. In this case, the snow is pressed so that it does not melt, it is folded into special polyethylene containers - big bags - and delivered to the place by truck.

Last year, the New League in several stages carried snow to Moscow, which was needed by the organizers of the Freestyle World Cup stage. The tournament was supposed to be held in the center of the city, in Gorky Park, the weather turned out to be very cold - minus fifteen, but completely dry. The organizers did not count on this, they did not set up snow cannons, and the participants have already gathered from all over the world. There was not a single snowflake in the air, and the snow parcel brought from Siberia on the last day before the tournament came in handy. Athletes and coaches themselves dragged the bags to the top of the artificial track - to the height of an eight-story building.

water volley

In general, natural snow is much less suitable for professional competitions - they usually use only artificial snow. Simply because it is much easier to drive it into the right quality framework to provide all athletes with a perfect glide.

Artificial does not mean synthetic. Nothing to do with sparkling polyethylene, snowdrifts lying around Christmas trees in apartments. Artificial means created not by nature, but by technology. But otherwise, this snow is no different from the present.

We are talking about the so-called snow guns - the most common means of correcting weather shortcomings. Today, such guns (officially they are called snow guns) are at all ski resorts.

The principle of their operation from the outside seems not very complicated, but one such generator is served by a huge expensive system. It includes not only the gun itself (mast, in the form of a high stick, or fan, like a large turbine), but also water intake devices, filters, even bactericidal in good resorts, a high-pressure pump, pipes for supplying water to each gun and electric cable. At the same time, pipes are usually buried in the ground so that they do not freeze.

Snow is made from pressurized water, said Is-SpoRt, a manufacturer and trader of ski slope equipment, to PP. - The system has two types of nozzles, mechanical atomizers. One is nucleators: here, water supplied by a high-pressure pump is mixed with compressed cooled air from a compressor, and a "snowflake germ" is obtained. The second is ordinary water nozzles, through which water is simply sprayed under high pressure.

Water particles, mixed with air in the nucleator, are ejected with force from tiny holes - with a sharp expansion, the air cools and freezes the water. At the same time, the smallest drops of ordinary water from another nozzle are glued to the “embryo”. The fan of the cannon drives all this away, the water freezes, falling to the ground with snow. The further the water flies away from the generator, the more time it has, the better the snow will turn out. That's all. No chemistry.

As a result, the banal spraying of water turns into a real science. It is easy to check its ingenuity, you just have to try to spray water from a spray bottle on a frosty night. Even if it has time to freeze, there will be no snow - there will be ice. And all because to get the perfect snowflake, you need to take into account the temperature of air, water, humidity and the necessary pressure.

Many conditions must be strictly observed, - says Ekaterina Selyametova. - If you need a large amount of snow, then the necessary condition is the air temperature minus five and below, and the temperature of the water that is poured into the snow cannons should not be higher than plus three. If you do not need a very large volume or have a lot of time left for preparation, then you can use guns that create ice chips - it can be used even at high positive temperatures: up to plus thirty. However, there is a nuance: ice chips are not suitable for professional competitions. It can be used as a base for snow or for recreational skiing.

The quality of snow is determined by its density. If for tourist routes a suitable density is from 380 to 420 kilograms per cubic meter, then for high-speed descent of snow it should be 500 kilograms per cubic meter. Its density depends on the structure of the snowflake: the less fluffy it is, the denser it is. All this can now be controlled on the snow machine, automatically setting the quality of the snow. For example, I ordered “snow quality No. 5” - and the equipment itself will do everything so that the output has a certain density. The weather station will determine the air temperature and humidity, and then the required water temperature and the desired pressure. Hypothetically, now all this can be done without human intervention, but after all, pressing the button should not be thoughtless.

Unfortunately, nothing can be solved by pressing a button, and the person responsible for the quality of the snow must be there, Selyametova assures. - They call him snowman. His task is to fully study a particular route, delve into its features, calculate what problems, including weather problems, may arise, and be ready for their prompt solution. And the quality of the snow is checked by hand.

Snowing a slope is not a cheap pleasure: 1 km of the route for a good European resort costs 1 million euros. The price depends on the time for which it is necessary to achieve the result: the more it is, the cheaper it is. Therefore, our resorts prefer to stretch the process for two weeks, while abroad they fit in a couple of days - until the weather conditions change. After all, artificial snow must be protected from direct sunlight and rain, and rain is especially terrible.

And yet, despite all the difficulties, artificial snow is wildly popular. The installation of such a system allows you to extend the tourist season for several months and almost always hold the necessary starts. And if something is covered, you can bring snow from afar. The only condition is that sub-zero temperatures are still desirable for all this. So to hold a snowboard contest in the middle of the Sahara is not yet possible. But in the city center in winter or even in spring - no problem.

The answer to the question is simple: "depending on whom and looking for what ...". If you're digging your car out in the morning after a nighttime snowfall - the third in a week - then five centimeters of snow will be more than enough! Imagine waiting until January to try out your new ski equipment. And finally, they were going to climb their favorite mountain ... And just at that time frosts hit, and then the thermometer stayed below minus 25 ° C until mid-April, after which the snow melted at an accelerated pace for a week ... What do you say in this case ?!

It is not surprising, therefore, that there are people who are willing to pay for what usually falls from the sky "for free". As, accordingly, there are those who produce this artificial snow. Many ski resorts, including those in Russia and Sweden, thanks to the use of special "snow-making" systems, extend the ski season by as much as four months (two in the beginning of winter and two in the spring). In addition, it should be noted that at this time the weather is the most mild and favorable, that is, ideal for a wonderful family vacation ...

HUNDRED NAMES FOR SNOW

It is said that in the languages ​​of Northern Scandinavia there are a hundred words for snow, which is not at all surprising. For there is plenty of this "goodness" here in winter, and the structure of snow itself is very changeable and dependent on temperature and humidity. Ski lovers are well aware that snow can be "hard", "soft", wet, etc. Sometimes skis run "by themselves", and literally the next day you need to make an effort even to move downhill.

In modern ski competitions, tenths of a second sometimes decide the fate of medals. And in alpine skiing, the score is already in the hundredths and thousandths! And now, after we have been looking forward to international competitions for a year or even two, we buy tickets ahead of time and book a hotel, the organizers suddenly cancel everything at the last moment. Since Heaven didn't "send" the much-needed snow to the right place, which instead fell all over again near your garage...

According to data from the Swedish Regional Climate Modeling Project (SWECLIM), by 2010 the average annual temperature in Sweden will increase by 3.8oC. It is estimated that warming in Northern Europe will be more significant than in other regions, which can bring big disappointments to winter sports fans. The expected increase in the annual precipitation rate is also expected to occur, most likely, due to summer and especially autumn rains. Together with an increase in average winter temperatures, this will lead to a decrease in snow cover and a later opening of the ski season. Moreover, problems with snow are typical not only for Scandinavia. For example, in the ski resorts of Eastern Siberia, the opening of the ski season in 2003 took place only on New Year's Eve, and in the winter of 1998-99 - only on January 3!

Thus, "artificial" snow in skiing represents stability and quality. Snow systems are used when control over the situation is needed: to ensure that the snow lies where it is needed, when it is needed, and the way it is needed. It should be noted that the use of snow systems goes beyond sports. "Artificial" snow can be used to test aircraft anti-icing systems, to test winter tires, and even to protect young forest plantations from frost.

IS IT EASY TO MAKE SNOW?

Most are sure that "making" snow is as easy as shelling pears - there would be water and frost. But this is only apparent simplicity. We offer those who live in cold climates a simple and safe experiment. Take a water spray that is commonly used to dampen houseplants or when ironing clothes. Fill it with cold water from the faucet, go outside on a cold (colder than -10°C) day, and start spraying the water higher into the air. What do you think you will be able to do? Big and fluffy snowflakes? Nothing of the kind - small shiny ... ice floes.

Why do snowflakes fall from the sky in winter? The "secret of their production", hidden high in the clouds, lies in the gradual growth of ice microcrystals on the so-called initial "condensation center" under certain conditions. If the conditions are unsuitable, instead of snowflakes, solid ice balls (summer hail) or what is called "groats" in Russia, that is, relatively dense, granular snow, characteristic of late autumn, will fall.

What is necessary for successful "snowmaking"? Obviously, water of a certain temperature, "splashed" in a certain way, cold air ... Also - some kind of natural "magic" or, at least, sophisticated technical equipment. And only then will we be able to announce with all confidence: let there be Snow! And he will!

LET'S LOOK INTO THE SNOW GUN

And now - for those inquisitive who are not afraid of some technical details. Snow machines in use today can be divided into two main types: fan (commonly called "snow guns") and mast. In Russia, generators of the first type are most common. The main unit of these devices, as the name suggests, is a high power fan that creates a continuous stream of air into which water droplets are then injected.

The mixture ejected by the generator must spend some time in the air before falling to the ground as well-formed snow. Therefore, it is difficult for a "snow gun" to throw snow "right under its feet", since the best snow is obtained at a distance of about 10-20 m from the installation. This is easier to do with special snow masts, which are also cheaper than fan guns.

All modern snow generators are equipped with automation systems of varying complexity (from overload protection systems to full control systems).

MAKING SNOW IS ART!

The modern snowmaking system is not limited to snow generators placed along the ski slope or track. Obviously, it is still necessary to lay pipes for supplying water and an electric cable. At the same time, pipes should not freeze even in the most severe frost, therefore they are usually dug into the ground (in Siberia and Central Sweden - to a depth of at least 50-70 cm). At certain intervals, you need to organize "connection points" of snow guns, including an electrical connector and water supply devices ("hydrant").

Do not forget that even a "simple" ski slope can be more than a kilometer long and have a height difference of 400-500 m. On such a slope, you will need to place about ten "connection points", and at the foot - a high-pressure water pump (up to 40 atmospheres) high performance. To throw a sufficient amount (usually 10-20 cm) of "artificial" snow on a kilometer-long slope, 4-5 "snow guns", each of which consumes up to 500 liters of water per minute (corresponding to about one average bath of water in 15 seconds), should work continuously for 5-7 days. In general, the performance of modern snow guns is amazing - they are capable of producing up to 100 m3 of snow per hour! "Snow guns" with a hydraulic rotary device are capable of covering up to 1000 m2 of surface with snow each.

Snowmaking a cross-country track is by no means easier. Here, of course, there are no such elevation changes as on the ski slopes or ski jumps, but the length of the tracks is already tens of kilometers long. Laying such long pipelines is quite expensive. That is why one of the common solutions is to install "snow guns" and water tanks on a self-propelled chassis, wheeled or tracked. In this case, snowmaking of any area is only a matter of time.

How to check how good freshly made snow is? Arrange a product "quality" check? Experts say that snow for a ski slope should have a density of 400 to 500 kg per m3, that is, be 2-2.5 times lighter than ice or water.

Density measurement is reduced to measuring the weight of a piece of "snow cake" of a certain size, carefully cut from the slope. There is, however, an easier way. Astute skiers may have noticed that snowmen (the main "snowmakers") are usually dressed in black jackets made of a special material. This is not just a uniform, but a kind of "tool" for checking the quality of snow. To do this, the "snowmaker" approaches the working "cannon" and puts his hand under the snow stream at a distance of about 15 m from the exit cut. After 15-20 seconds (the exact figures are a trade secret!) the specialist steps aside and shakes the snow off his sleeve, dangling his hand. Then he checks what is stuck on the fabric. If all the snow has been shaken off, it is too dry. If it's all left, it's too wet. The desired quality lies somewhere in the middle. And just here the art of "snowmaking" begins.

RECIPE FOR GOOD SNOW

Modern snow guns have a sufficient number of "degrees of freedom" to adjust and ensure good snow quality at any sufficiently low air temperature. But what if the external conditions (air temperature, humidity) change rapidly? It is clear that in this case it is necessary to constantly adjust the "tuning" of the generator so that the quality of the snow produced does not decrease. Fortunately, with automation, the operator does not have to run up and down the slope to reset the system. Moreover, automatic adjustment can be carried out both at the level of an individual snow gun, and at the level of the entire snowmaking system as a whole. Complex automation systems, which include microprocessors and stationary computers, as well as "weather stations" can work without much human intervention for weeks and months.

To use a restaurant analogy, the recipe for good "snowmaking" using an automated system is more like an instruction manual for some modern bread machine: "put flour, yeast, pour water, press the button and wait for the call - it's done!" Of course, no self-respecting chef will allow himself anything like this: everything will be done traditionally, in "manual mode", adjusted for "scent and sight". Likewise, a good "snowmaker", who has many years of work behind him, will regulate the system taking into account many factors known only to him: was there a "halo" around the sun today, how did the snow crunch yesterday, what color was the sunset, and God knows what more... However, both a good cook and a skilled "snowmaker" are not easy to find, and they have to pay astronomical sums. Computer automation is cheaper, easier to manage, and does not argue if you have to work overtime.

By the way, at international competitions, where the "cream" of the sports beau monde hang out, the snow is prepared by just not unique specialists. Modern sporting events require, where possible, standard equipment and standard conditions of conduct in order to ensure equality for all participants. Therefore, more and more competition organizers are turning to automated snowmaking systems even with a sufficient amount of natural snow, which is very difficult to standardize.

In northern Europe for the period 1990-2100. Significant climate changes are expected due to an increase in average winter temperatures (A) and annual precipitation (B).

Production of "artificial" snow for more than 50 years. The first experimental installations began to be created in the 1950s and 60s. in countries where skiing was very popular. Patents for artificial snow were filed in 1968.

In fan snow "cannons" a powerful fan (4) creates a continuous flow of air that moves through the main (1) and nucleation (2) rings with nozzles. Water is supplied under pressure to the first rings, and a water-air mixture is supplied to the second.

Through the nozzles of the main rings, tiny water droplets are injected into the air stream. The nozzles of the "nucleation" ring create the condensation centers necessary for the formation and growth of snow.

Between the fan and the rings there are blade-plates (3) attached from the inside to the generator casing. They contribute to better mixing of the components of the water-air mixture.

Many snow guns use multiple main rings, each with a separate water valve. Thanks to this, the performance of the snow gun can be controlled. The main components are enclosed in a metal casing (6) with a protective mesh (5) at the system inlet.

The snow machine also has devices for supplying electricity (7), high pressure water (9) and compressed air (8).

Fan snow guns can also be mounted on a self-propelled tracked chassis
In snow cannons, the snow gun housing (D), automation system (A) and compressor (C) are mounted either on a wheeled chassis or on a solid "leg" (T). Water is supplied through a hose with a special connector for quick connection (W). Control signals (CS) are given from the central computer system via a separate "signal cable" or by radio

At the snow "mast", the snow-generating elements are raised above the ground to a height of up to 10 m. Thanks to this, all the sprayed water has time to completely condense in the form of snow, while the latter falls to the ground under its own weight.

The work of preparing a snow slope or track is not limited to the production of snow. After generation, the snow should "lay down" for several days ("ripen", as young wine ripens). After that, it is the turn of special snow machines (the so-called pistmachines or retraks), which level the snow, compact and soften its surface.

In conclusion, we want to wish the readers good snow - for the current and all future ski seasons! We also want to wish those who have not yet joined the ski "fun" to try at least once. After all, today's opportunities for ski enthusiasts of all ages and any qualifications are simply inexhaustible!

Aside from the obvious health benefits of spending time outdoors while combating the effects of physical inactivity, skiing is a lot of fun! Well, when you find yourself back on your favorite slope, you can competently tell your friends about how much effort and knowledge is hidden behind seemingly so simple and familiar "perfect" snow.

The authors:
KOPTYUG Andrey Valentinovich - Candidate of Physical and Mathematical Sciences, graduate of Novosibirsk State University. Associate Professor at the Faculty of Information Technology at the University of Central Sweden (Östersund)
ANANEV Leonid Grigorievich - director of the Swedish-Russian company SveRuss Konsul (SveRuss Konsul) (Sweden, Östersund)
OSTREM Johan - MSc in Engineering, director of AREKO Snowsystem (ARECO Snowsystem) (Sweden, Östersund)

The article is printed in abbreviated form.

Our company offers snow cover services at the Customer's site: delivery, installation and maintenance of special equipment - snow guns, snow guns with a capacity of 3 to 120 cubic meters. meters of snow per hour.

How to make artificial snow?

When the reader of this article learns that its authors live and work in Central Sweden - about 500 km north of Stockholm, which roughly corresponds to the latitude of Kandalaksha - he may have legitimate bewilderment. "To the North Pole - and with your own snow?" - he will ask, remembering the Snow Queen, familiar from childhood. For whom is a meter layer of snow not enough in winter?

The answer to the question is simple: "depending on whom and looking for what ...". If you're digging your car out in the morning after a nighttime snowfall - the third in a week - then five centimeters of snow will be more than enough! Imagine waiting until January to try out your new ski equipment. And finally, they were going to climb their favorite mountain ... And just at that time frosts hit, and then the thermometer stayed below minus 25 ° C until mid-April, after which the snow melted at an accelerated pace for a week ... What do you say in this case ?!

It is not surprising, therefore, that there are people who are willing to pay for what usually falls from the sky "for free". As, accordingly, there are those who produce this artificial snow. Many ski resorts, including those in Russia and Sweden, thanks to the use of special "snow-making" systems, extend the ski season by as much as four months (two in the beginning of winter and two in the spring). In addition, it should be noted that at this time the weather is the most mild and favorable, that is, ideal for a wonderful family vacation ...

HUNDRED NAMES FOR SNOW.

It is said that in the languages ​​of Northern Scandinavia there are a hundred words for snow, which is not at all surprising. For there is plenty of this "goodness" here in winter, and the structure of snow itself is very changeable and dependent on temperature and humidity. Ski lovers are well aware that snow can be "hard", "soft", wet, etc. Sometimes skis run "by themselves", and literally the next day you need to make an effort even to move downhill.

In modern ski competitions, tenths of a second sometimes decide the fate of medals. And in alpine skiing, the score is already in the hundredths and thousandths! And now, after we have been looking forward to international competitions for a year or even two, we buy tickets ahead of time and book a hotel, the organizers suddenly cancel everything at the last moment. Since Heaven didn't "send" the much-needed snow to the right place, which instead fell all over again near your garage...

According to data from the Swedish Regional Climate Modeling Project (SWECLIM), by 2010 the average annual temperature in Sweden will increase by 3.8oC. It is estimated that warming in Northern Europe will be more significant than in other regions, which can bring big disappointments to winter sports fans. The expected increase in the annual precipitation rate is also expected to occur, most likely, due to summer and especially autumn rains. Together with an increase in average winter temperatures, this will lead to a decrease in snow cover and a later opening of the ski season. Moreover, problems with snow are typical not only for Scandinavia. For example, in the ski resorts of Eastern Siberia, the opening of the ski season in 2003 took place only on New Year's Eve, and in the winter of 1998-99 - only on January 3!

Thus, "artificial" snow in skiing represents stability and quality. Snow systems are used when control over the situation is needed: to ensure that the snow lies where it is needed, when it is needed, and the way it is needed. It should be noted that the use of snow systems goes beyond sports. "Artificial" snow can be used to test aircraft anti-icing systems, to test winter tires, and even to protect young forest plantations from frost.

IS IT EASY TO MAKE SNOW?

Most are sure that "making" snow is as easy as shelling pears - there would be water and frost. But this is only apparent simplicity. We offer those who live in cold climates a simple and safe experiment. Take a water spray that is commonly used to dampen houseplants or when ironing clothes. Fill it with cold water from the faucet, go outside on a cold (colder than -10°C) day, and start spraying the water higher into the air. What do you think you will be able to do? Big and fluffy snowflakes? Nothing of the kind - small shiny ... ice floes.

Why do snowflakes fall from the sky in winter? The "secret of their production", hidden high in the clouds, lies in the gradual growth of ice microcrystals on the so-called initial "condensation center" under certain conditions. If the conditions are unsuitable, instead of snowflakes, solid ice balls (summer hail) or what is called "groats" in Russia, that is, relatively dense, granular snow, characteristic of late autumn, will fall.

What is necessary for successful "snowmaking"? Obviously, water of a certain temperature, "splashed" in a certain way, cold air ... Also - some kind of natural "magic" or, at least, sophisticated technical equipment. And only then will we be able to announce with all confidence: let there be Snow! And he will!

LET'S LOOK INTO THE SNOW GUN.

And now - for those inquisitive who are not afraid of some technical details. Snow machines in use today can be divided into two main types: fan (commonly called "snow guns") and mast. In Russia, generators of the first type are most common. The main unit of these devices, as the name suggests, is a high power fan that creates a continuous stream of air into which water droplets are then injected.

The mixture ejected by the generator must spend some time in the air before falling to the ground as well-formed snow. Therefore, it is difficult for a "snow gun" to throw snow "right under its feet", since the best snow is obtained at a distance of about 10-20 m from the installation. This is easier to do with special snow masts, which are also cheaper than fan guns.

All modern snow generators are equipped with automation systems of varying complexity (from overload protection systems to full control systems).

MAKING SNOW IS AN ART.

The modern snowmaking system is not limited to snow generators placed along the ski slope or track. Obviously, it is still necessary to lay pipes for supplying water and an electric cable. At the same time, pipes should not freeze even in the most severe frost, therefore they are usually dug into the ground (in Siberia and Central Sweden - to a depth of at least 50-70 cm). At certain intervals, you need to organize "connection points" of snow guns, including an electrical connector and water supply devices ("hydrant").

Do not forget that even a "simple" ski slope can be more than a kilometer long and have a height difference of 400-500 m. On such a slope, you will need to place about ten "connection points", and at the foot - a high-pressure water pump (up to 40 atmospheres) high performance. To throw a sufficient amount (usually 10-20 cm) of "artificial" snow on a kilometer-long slope, 4-5 "snow guns", each of which consumes up to 500 liters of water per minute (corresponding to about one average bath of water in 15 seconds), should work continuously for 5-7 days. In general, the performance of modern snow guns is amazing - they are capable of producing up to 100 m3 of snow per hour! "Snow guns" with a hydraulic rotary device are capable of covering up to 1000 m2 of surface with snow each.

Snowmaking a cross-country track is by no means easier. Here, of course, there are no such elevation changes as on the ski slopes or ski jumps, but the length of the tracks is already tens of kilometers long. Laying such long pipelines is quite expensive. That is why one of the common solutions is to install "snow guns" and water tanks on a self-propelled chassis, wheeled or tracked. In this case, snowmaking of any area is only a matter of time.

How to check how good freshly made snow is? Arrange a product "quality" check? Experts say that snow for a ski slope should have a density of 400 to 500 kg per m3, that is, be 2-2.5 times lighter than ice or water.

Density measurement is reduced to measuring the weight of a piece of "snow cake" of a certain size, carefully cut from the slope. There is, however, an easier way. Astute skiers may have noticed that snowmen (the main "snowmakers") are usually dressed in black jackets made of a special material. This is not just a uniform, but a kind of "tool" for checking the quality of snow. To do this, the "snowmaker" approaches the working "cannon" and puts his hand under the snow stream at a distance of about 15 m from the exit cut. After 15-20 seconds (the exact figures are a trade secret!) the specialist steps aside and shakes the snow off his sleeve, dangling his hand. Then he checks what is stuck on the fabric. If all the snow has been shaken off, it is too dry. If it's all left, it's too wet. The desired quality lies somewhere in the middle. And just here the art of "snowmaking" begins.

RECIPE FOR GOOD SNOW.

Modern snow guns have a sufficient number of "degrees of freedom" to adjust and ensure good snow quality at any sufficiently low air temperature. But what if the external conditions (air temperature, humidity) change rapidly? It is clear that in this case it is necessary to constantly adjust the "tuning" of the generator so that the quality of the snow produced does not decrease. Fortunately, with automation, the operator does not have to run up and down the slope to reset the system. Moreover, automatic adjustment can be carried out both at the level of an individual snow gun, and at the level of the entire snowmaking system as a whole. Complex automation systems, which include microprocessors and stationary computers, as well as "weather stations" can work without much human intervention for weeks and months.

To use a restaurant analogy, the recipe for good "snowmaking" using an automated system is more like an instruction manual for some modern bread machine: "put flour, yeast, pour water, press the button and wait for the call - it's done!" Of course, no self-respecting chef will allow himself anything like this: everything will be done traditionally, in "manual mode", adjusted for "scent and sight". Likewise, a good "snowmaker", who has many years of work behind him, will regulate the system taking into account many factors known only to him: was there a "halo" around the sun today, how did the snow crunch yesterday, what color was the sunset, and God knows what more... However, both a good cook and a skilled "snowmaker" are not easy to find, and they have to pay astronomical sums. Computer automation is cheaper, easier to manage, and does not argue if you have to work overtime.

By the way, at international competitions, where the "cream" of the sports beau monde hang out, the snow is prepared by just not unique specialists. Modern sporting events require, where possible, standard equipment and standard conditions of conduct in order to ensure equality for all participants. Therefore, more and more competition organizers are turning to automated snowmaking systems even with a sufficient amount of natural snow, which is very difficult to standardize.

In northern Europe for the period 1990-2100. Significant climate changes are expected due to an increase in average winter temperatures (A) and annual precipitation (B).

Production of "artificial" snow for more than 50 years. The first experimental installations began to be created in the 1950s and 60s. in countries where skiing was very popular. Patents for artificial snow were filed in 1968.

In fan snow "cannons" a powerful fan (4) creates a continuous flow of air that moves through the main (1) and nucleation (2) rings with nozzles. Water is supplied under pressure to the first rings, and a water-air mixture is supplied to the second.

Through the nozzles of the main rings, tiny water droplets are injected into the air stream. The nozzles of the "nucleation" ring create the condensation centers necessary for the formation and growth of snow.

Between the fan and the rings there are blade-plates (3) attached from the inside to the generator casing. They contribute to better mixing of the components of the water-air mixture.

Many snow guns use multiple main rings, each with a separate water valve. Thanks to this, the performance of the snow gun can be controlled. The main components are enclosed in a metal casing (6) with a protective mesh (5) at the system inlet.

The snow machine also has devices for supplying electricity (7), high pressure water (9) and compressed air (8).

"Fan" snow guns can also be installed on a self-propelled tracked chassis.

In snow cannons, the snow gun housing (D), automation system (A) and compressor (C) are mounted either on a wheeled chassis or on a solid "leg" (T). Water is supplied through a hose with a special connector for quick connection (W). Control signals (CS) are given from the central computer system via a separate "signal cable" or by radio

At the snow "mast", the snow-generating elements are raised above the ground to a height of up to 10 m. Thanks to this, all the sprayed water has time to completely condense in the form of snow, while the latter falls to the ground under its own weight.

The work of preparing a snow slope or track is not limited to the production of snow. After generation, the snow should "lay down" for several days ("ripen", as young wine ripens). After that, it is the turn of special snow machines (the so-called pistmachines or retraks), which level the snow, compact and soften its surface.

In conclusion, we want to wish the readers good snow - for the current and all future ski seasons! We also want to wish those who have not yet joined the ski "fun" to try at least once. Indeed, today's opportunities for ski enthusiasts of all ages and any qualifications are simply inexhaustible!

Aside from the obvious health benefits of spending time outdoors while combating the effects of physical inactivity, skiing is a lot of fun! Well, when you find yourself back on your favorite slope, you can competently tell your friends about how much effort and knowledge is hidden behind seemingly so simple and familiar "perfect" snow.

The authors:
KOPTYUG Andrey Valentinovich - Candidate of Physical and Mathematical Sciences, graduate of Novosibirsk State University. Associate Professor at the Faculty of Information Technology at the University of Central Sweden (Östersund).
ANANEV Leonid Grigorievich - Director of the Swedish-Russian company SveRuss Konsul (SveRuss Konsul) (Sweden, Östersund)
OSTREM Johan - MSc in Engineering, director of AREKO Snowsystem (Sweden, Östersund).

The article is printed in abbreviated form.

There are more and more people skiing and snowboarding, and there are fewer and fewer places suitable for skiing.

Global warming has reduced the season at some of the oldest ski resorts from four months to one or two. There are forecasts according to which the center of the European ski industry will soon shift from the Alps to Scandinavia. In search of snow, Americans have already begun to explore Alaska. Everything, there is nowhere else to go. It remains only to use weapons. Special. If you didn’t go beyond the Arctic Circle for snow, then most likely, at your favorite resort you ride on ersatz - artificial, or technical, as professionals call it, snow. Today, not a single resort can do without special snow-making machines, from French Chamonix to Volen near Moscow. Almost every rider has seen snow guns in action and their lighter versions - snow guns. From the outside, the process of snow formation looks simple: giant fans spray water, which turns into snow in the cold. But this is only from the side.

real snow

Natural snow is formed from atmospheric water vapor. When water vapor, which is the gaseous form of water, cools to the point of condensation, it changes from gaseous to liquid or solid form. The clouds we are accustomed to consist of just such condensed drops, though so small that they are easily kept at the top by rising air currents. When the droplets become too heavy, they fall to the ground as rain. If the temperature is much below the dew point, water vapor bypasses the liquid phase, forming small crystals. In most parts of the globe, the usual rain for us begins, oddly enough, with a snowfall, but the snowflakes have time to melt as they approach the ground. The fact is that at the height of the formation of clouds there is always a negative temperature, comparable to the Yakut frosts. A simple confirmation of this fact is hail in a hot summer.

However, water does not automatically freeze when the temperature falls below freezing. Distilled water can be cooled down to a fairly low temperature of -40°C and still remain a liquid. However, in real life, the vapor in the clouds begins to crystallize already at 0 °C. The fact is that in order for the process of condensation to start, water needs the smallest particles around which its molecules could settle. Such centers of condensation in the atmosphere are the smallest particles of soot, urban smog, bacteria and other materials. For example, this is how clouds are dispersed by spraying special reagents (for example, silver iodide) from aircraft over them, which act as just such centers of condensation.

Crystallizing, the water in the clouds forms bizarre six-beam fractal shapes called snowflakes. The longer the crystallization process takes, the more complex the pattern of the snowflake. In the clouds, this process takes tens of minutes. Artificial snow, on the other hand, forms in seconds, so upon closer inspection, its crystals look like hexagonal ones with ray nuclei, and feel like grains to the touch. However, such snow melts more slowly than natural snow, and skis on it glide differently.

snow guns

The idea used to disperse clouds (condensation of water around artificial condensation centers) is also perfectly suited for the production of artificial snow. One of the most common crystallizers used in snowmaking is Snowmax, a special natural protein that does an excellent job of attracting water molecules.

In the early designs of snow guns, water was mixed with compressed air and expelled through nozzles at high pressure into a stream of air generated by a powerful fan. Compressed air performed three tasks at once: it sprayed water, threw the resulting droplets into the air, and additionally cooled the water. The latter effect is based on the fact that during adiabatic expansion, gases are cooled. Try to open a can of carbon dioxide - it will instantly cool to sub-zero temperatures, risking frostbite on your hands.

The disadvantage of this scheme is the high air consumption. Therefore, more modern guns operate in a two-stage process. First, by mixing compressed air and a small amount of water, tiny ice crystals are formed - the embryos of artificial snow. Then these "embryos" fall into the stream of water sprayed by powerful fans, which, crystallizing on them, quickly forms ready-made snow crystals.

A distinctive feature of all guns is a powerful fan that ejects a water-air mixture over tens of meters. During such a flight, crystals of artificial snow have time to form, besides, the high "range" allows you to snow large areas. In ski resorts, you can also see another type of snow gun - snow guns. Their difference from guns is in the absence of a fan.

The process of snow formation in them is as follows. The spaced apart air and first water nozzles supply a limited amount of water and air to the mixing zone, located at a distance of 810 cm from the gun, where snow crystals form. These mini-crystals are displaced by inertia further, at a distance of approximately 20 cm from the gun, they enter the water stream from the second nozzle, where water sticks to them. Snow crystallization occurs during the free fall of crystals to the ground from a height of at least 4 m.

Snow conditions

The presence of snow artillery does not yet mean the solution of snow problems. Much also depends on the conditions of snow formation, the most important parameters of which are temperature and relative humidity (the ratio of water vapor actually contained in the air to the amount of water vapor corresponding to the state of saturation). The fact is that water is cooled by its own partial evaporation, that is, the transition of part of the liquid into vapor. However, the higher the relative humidity, the slower will be the evaporation process and, consequently, the cooling.

Therefore, at low relative humidity, snow formation is possible at temperatures above 00C. At high humidity and at low temperatures, it is possible to get ordinary rain instead of snow. With a relative humidity of 30%, it is possible to run snow guns at -1°C, which is considered good conditions for snow formation. If the temperature falls below -6.7°C, then it is possible to make snow even at 100% relative humidity. At temperatures below -10°C, humidity can be ignored.