EP0605824B1 - Snow gun - Google Patents

Abstract

The gun housing (1') forms an air passage open at both ends and contains a motor-driven fan (4), also a water nozzle (7) at the outlet end (3). This delivers the water into the air current (8) in a finely-divided state. Water flow is controlled by a valve (9) in the pipe (10) delivering the water to the nozzle under pressure. Valve operation is electrically or electronically controlled (11), and temperature sensors have their active portions in the path of the current. A system keeps the active portion of a first sensor permanently moist. The valve is controlled dependent on the actual temperature detected by one sensor, while also taking into account the difference between this temperature and that detected by the other sensor.

Description

The invention relates to a snow cannon according to the preamble of claim 1.

Snow cannons are increasingly being used today to ensure the ski season and the ability to drive downhill runs or slopes even in the absence or insufficient snowfall, these cannons generally being operated at night. It is common for the snow cannons to be set manually by the respective operating personnel in dependence on the current weather conditions, although constant monitoring and regulation is not possible for reasons of time, but also because of the arrangement of these cannons in the field, rather the monitoring can and regulation are currently only carried out sporadically. Optimal snowmaking on a terrain or a slope with the usual snow cannons today, especially with optimal use of the water used, is not possible. For example, sudden changes in the weather data can lead to the fact that the amount of water introduced or atomized into the air stream escaping from the snow cannon does not change or only partially changes its physical state, i.e. Artificial snow forms while a large part of the atomized water reaches the slopes or the terrain as water or extremely moist snow, with the result that expensive treated water is lost and, in addition, ice plates or may also be lost - Form areas that affect the quality of the downhill run and also represent an unnecessary environmental impact. "Artificial snow" in the sense of the invention is the snow produced with a snow cannon.

A system for producing artificial snow is known (EP-A-0 004 803), in which several snow cannons are connected locally to a central control and supply unit, which not only supplies the individual snow cannons with water and possibly also with compressed air supplied, but also controls these snow cannons, depending on measuring stations, which are arranged with their sensors outside the snow cannon in the field and for measuring the Serve wind speed, wind direction, air temperature and relative humidity. If only because the measuring stations are not intended and suitable for measuring the thermal energy (enthalpy) that is present in the air stream flowing through the air duct of the snow cannon, the known system is not suitable for critical weather conditions, i.e. at temperatures in the range from 0 ° C to produce artificial snow in optimal quantities and with optimal quality. In addition, hygrometers, such as those used by the measuring stations of the known system, have long response times (between 30 and 60 minutes), especially in these critical weather situations, which do not make it possible to regulate changes in the weather situation.

To determine the relative humidity, it is also known to measure the temperature of an air stream with a dry thermometer and at the same time with a moist thermometer, but without any reference to a snow cannon and its control.

The object of the invention is to show a snow cannon which enables a site to be illuminated in an optimal manner and taking into account the respective weather conditions.

To solve this problem, a snow cannon is designed according to the characterizing part of patent claim 1.

In the snow cannon according to the invention, both the temperature at the moist temperature sensor (“second temperature sensor”) and the temperature at the dry temperature sensor are detected during operation in the air flow flowing through the air duct or in an air flow proportional thereto. These values are used to determine the "cold energy" (enthalpy) of the ambient air or the air of the exiting air flow, taking into account the difference between the temperatures of the two temperature sensors and the actual temperature of one of these two temperature sensors, preferably the dry, second temperature sensor. With the help of a signal that takes these values and any other parameters, such as Temperature of the water supplied, desired snow quality, etc., the amount of water added to the exiting air stream, i.e. regulates the amount of water atomized in this air stream. This regulation can either be proportional, for example by means of a proportional valve, or stepwise, i.e. For example, take place in several switching stages in such a way that a specific number of water outlet nozzles is activated or switched on depending on the amount of water to be introduced into the emerging air stream.

In a possible embodiment of the invention, a plurality of snow cannons, which are arranged in a distributed manner on a downhill run or runway, are connected to a common monitoring and control device via at least one common data line, so that the snow cannons are monitored and controlled by a control center via the control lines or the bus system can be optimally controlled.

If fully automatic or centrally controlled operation of the snow cannon is planned, it is connected to a frost-proof water supply line via a valve control. The valve device is designed that the snow cannon and its water-carrying lines are emptied automatically after switching off. To the extent that this is necessary for the automatic emptying, all control valves of the snow cannon also open after this cannon has been switched off. Furthermore, all control valves are also frost-proof or heated, as are the nozzles.

Developments of the invention are the subject of the dependent claims.

Fig. 1

in schematischer Darstellung eine Schneekanone gemäß der Erfindung, zusammen mit der dieser Schneekanone zugeordneten Steuereinrichtung;

Fig. 2

in schematischer Darstellung eine Sensoreinrichtung der Schneekanone nach Fig. 1,

Fig. 3

in vereinfachter Darstellung eine weitere Ausführung der Erfindung.

The invention is explained in more detail below with reference to the figures using exemplary embodiments. Show it:

Fig. 1

in a schematic representation a snow cannon according to the invention, together with the control device assigned to this snow cannon;

Fig. 2

a schematic representation of a sensor device of the snow cannon according to FIG. 1,

Fig. 3

in a simplified representation another embodiment of the invention.

In the figures, 1 'is the tubular housing of a snow cannon 1. This tubular housing, which is open on the two housing sides 2 and 3, i.e. there is essentially only provided with a protective grille (not shown), forms an air duct narrowing towards the end 3 and can be pivoted or adjusted on a fixed or mobile frame (not shown) about a horizontal axis running perpendicular to the longitudinal axis L of the housing.

Ambient air is drawn in via the open end 2 in the manner described in more detail. This end thus forms the suction area of the snow cannon 1 or the housing 1 '. At the end 3, the ambient air is blown out and water is sprayed into the air stream 8 there to form the artificial snow.

A vent wheel 4 is provided in the interior of the housing 1 'and can be driven by an electric motor about an axis coaxially with the longitudinal axis L. In the illustrated embodiment, the fan wheel 4 is arranged so that it is closer to the end 2 than the end 3.

At the end 3, a plurality of annular distributor lines 5 are provided, of which only two distributor lines 5 are shown for the sake of simplicity. However, the number of distribution lines is actually higher, for example twelve.

Each distribution line 5 is made from a length of pipe section made of a non-corrosive material, for example stainless steel, in such a way that it forms a self-contained annular line. In the embodiment shown, the distribution lines 5 are arranged such that their ring axes are each coaxially with the longitudinal axis L and follow one another in the direction of the longitudinal axis L. However, other arrangements are also possible, for example in the form that the distributor lines are provided at least partially concentrically with one another at the end 3 outside the housing 1. Each distributor line 5 is part of a nozzle arrangement 6 and for this purpose is provided with a multiplicity of water outlet nozzles 7 which are distributed evenly around the longitudinal axis L on each distributor line or are provided in a different manner. The water outlet nozzles 7 on the distribution lines 5 are oriented so that they supply water in a finely divided form, i.e. finely atomized, into the air stream 8 emerging at the end 3.

The distribution lines 5 are each via a control or. Solenoid valve 9 connected to a line 10 which serves to supply water under pressure. A separate solenoid valve 9 is provided for each nozzle arrangement.

The solenoid valves 9 are normally in the closed state and open each time the associated magnet is actuated, whereby the associated nozzle arrangement 6 is then activated for dispensing water via the water outlet nozzles 7 provided there.

In order to obtain the greatest possible amount of artificial snow with the required quality and, in particular, to prevent water from being discharged with the air stream 8 instead of snow, it is necessary to adjust the amount of water introduced into the air stream 8 as a function of temperature and To control the humidity of the ambient air, specifically by activating a number of distributor lines 5 or nozzle arrangements 6 corresponding to the respectively permissible amount of water by opening the associated solenoid valve 9. For this control, a microprocessor-based control device 11 is used, which has different outputs, namely one output 12 for each solenoid valve 9. In the embodiment shown, the control device 11 also has an output 13 for an analog control signal and a data interface 14 for on - or delivery of data, for example status information.

The control device 11 has various inputs, namely an input 15 which is connected to a temperature sensor 16 provided in the line 10 and measuring the temperature of the water supplied, an input 17 which is connected to an adjusting element 18, and two further inputs 19 and 20, which are connected to a sensor device 21. This is in the area of the end 2, i.e. H. arranged in the suction area inside the tubular housing 1 '.

The setting element 18, which in the simplest case is a potentiometer, forms a manually adjustable element with which the desired quality of the artificial snow can be set or preselected, namely between "moist" and "dry". With the sensor element 21 internal energy of the sucked-in ambient air, which (energy) is available for the formation of the artificial snow by introducing water into the air stream 8.

As particularly shown in FIG. 2, the sensor device 21 consists of two temperature sensors 22 and 23, which are connected to one at the suction area, i.e. are provided in the area of the end 2 on the board 1 held on the housing 1, specifically with their respectively active area 22 ′ or 23 ′ at an opening 24 ′, through which a predetermined or defined proportion of the total air sucked in by the fan wheel 4 flows becomes. The circuit board 24 with the temperature sensors 22 and 23 is located in the flow direction in front of the fan wheel 4.

One end of a fabric or gauze hose 25 is plugged onto the active area 23 'of the temperature sensor 23, the other end of which is pushed onto the open end of a vertical pipe piece 26 which is open at both ends and which forms the outlet of a bottle-like container 27. This is fastened to the circuit board 24 or in a holder there, in such a way that the pipe section 26 or the opening of the container 27 formed by it lies below. The container 27 is filled with a liquid that only freezes at very low temperatures, for example with a mixture of water and an antifreeze. The cross section of the pipe section 26 is selected so that only a small amount of liquid is dispensed from the container 27 to the hose 25, and only so much around this hose and in particular also the end of this pushed onto the active region 23 ' To keep the hose moist.

Like the temperature sensor 16, the temperature sensors 22 and 23 are preferably each formed by a PT 100.

The control of the amount of water introduced into the air flow 8, ie the number of activated nozzle arrangements 6, is carried out by the control device 11 taking into account the setting on the setting element 18 and the temperature of the water supplied (signal from the temperature sensor 16) as a function of the difference between the signals from the temperature sensors 22 and 23 and also taking into account the actual temperature measured by the dry temperature sensor 22, in such a way that only below a predetermined minimum temperature, for example a temperature of less than +4 ^o C, one or more distribution lines 5 are activated at all. With an increasing difference in the temperatures determined by the temperature sensors 22 and 23 and also with an increasing difference between the minimum temperature and the actual temperature determined by the temperature sensor 22, the amount of water introduced into the air stream 8, ie the number of activated distributor lines 5, is increased.

The corresponding control curve, for example in the form of a family of curves for different snow qualities set on the setting device 18, according to which the (control curve) the control device 11 determines the maximum permissible amount of water to be introduced into the air stream 8 or the maximum permissible number of distributor lines 5 to be activated, is selected so that taking into account the signals present at inputs 19 and 20, ie taking into account the temperature difference of the temperature sensors 22 and 23 and taking into account the actual temperature of the temperature sensor 22, an artificial snow with the desired quality is actually obtained.

The, for example, analog signal present at the output 13 is also a measure of the amount of water that can be introduced into the air flow 8, taking into account the signals present at the inputs 15, 17, 19 and 20. The signal at the output 13 can be used, for example, to control a proportional valve which regulates the amount of water discharged into the air stream 8. In this embodiment, for example, all the water outlet nozzles 7 are then provided on a common distributor line, which are connected via the proportional valve to the line 10 for supplying the pressurized water.

Various information is available at the output 14, for example the temperature of the ambient air or air drawn in by the temperature sensor 22, the maximum possible amount of snow, etc. This data is displayed, for example, on a display device, not shown, of the snow cannon. 28 generally designates an electrical supply line via which the snow cannon and in particular also the drive for the air wheel and the control device 11 are supplied with electricity.

In principle, it is also possible to install the snow cannon 1a with other snow cannons in a terrain at suitable points, for example at bases 29 provided there (FIG. 3), and then to distribute them in the terrain, ie in the area of a snow downhill run to centrally control snow cannons 1a arranged at different altitudes. For this purpose, the outputs 14 of the control devices 11 of all snow cannons are connected to a common data line 30 which is used to transmit addresses and data to the individual snow cannons or their control devices 11 and to transmit addresses and data from the individual snow cannons or their control devices 11 to the central control and monitoring unit 31. From this central monitoring and control unit 31, the snow cannons can then be optimally controlled depending on, in particular, the data supplied by the sensor devices 21 or the temperature sensors 22 and 23, in particular also with regard to an optimal use of the water used, for example in such a way that only that snow cannon 1a is operated in a certain section of the route which, due to the temperature and humidity conditions of the ambient air there, enables the greatest emission of artificial snow. The one with This selected snow cannon artificial snow is then distributed to the required areas, for example with slope processing equipment.

Furthermore, the central control and monitoring device 31 also makes it possible to produce artificial snow in a controlled manner over a longer distance only where this is possible and absolutely necessary.

In the snow cannon 1a shown in FIG. 3 and fixedly mounted on the base 29, the line 10 is designed as a vertical riser. The line 10 is connected to a water supply line 33 laid in the floor 32 in a frost-proof manner, specifically via a valve 34, which is also located in the floor 32 at a frost-proof location. The valve 34, which is also controlled by the control device 11, is a changeover valve or a three / two-way valve, i.e. a valve with a total of three connections and two positions. In the one position, the valve 34 connects the line 10 to the line 33. In the other position, the valve 34 connects the line 10 to a line 36 laid in the floor 32 and leading to a drainage 35. This means that when the associated one is switched off Snow cannon 1a the associated line 10 is immediately emptied via line 36, so that line 10 cannot freeze after the snow cannon has been switched off.

In this embodiment, the valves controlling the water outlet nozzles 7, for example the solenoid valves 9 or the proportional valve driven by the outlet 13 and designated 37 in FIG the valves controlling the water outlet nozzles 7 are automatically opened after the snow cannon in question has been switched off, so that the water outlet nozzles 7 or the distributor lines 5 having these nozzles or connecting lines leading to these distributor lines can also be emptied.

The invention has been described above using exemplary embodiments. It goes without saying that changes and modifications are possible without departing from the inventive idea on which the invention is based.

For example, it is possible to provide electrical heating elements for the water outlet nozzles 7, the distribution lines 5, the solenoid valves 9 and the line 10, by means of which the aforementioned elements counteract at least until they are completely manually emptied or automatically emptied via the valve 34 after the snow cannon has been switched off Freezes are protected.

Reference list

1, 1a

Snow cannon

1'

casing

2, 3

The End

4th

Fan wheel

5

Distribution line

6

Nozzle arrangement

7

jet

8th

Airflow

9

magnetic valve

10th

management

11

Control device

12, 13, 14

exit

15

entrance

16

Temperature sensor

17th

entrance

18th

Adjustment device

19, 20

entrance

21

Sensor device

22, 23

Temperature sensor

22 ', 23'

active area

24th

circuit board

24 '

opening

25th

Fabric hose

26

Pipe piece

27

container

28

electrical supply line

29

base

30th

Data line

31

Control and monitoring device

32

ground

33

Water pipe

34

Valve

35

drainage

36

management

37

Proportional valve

Claims (13)

1. Snow cannon with a housing (1') forming at least one air duct open at both ends, with a blower (4) disposed in the air duct and driven by a motor, with at least one water outlet nozzle (7) at an opening (3) on the output side in the air duct for introducing water in suspended form into the flow of air (8) passing out at this end, and with means for controlling the quantity of water introduced via the water outlet nozzle (7), of which there is at least one, into the flow of air (8) passing out, wherein the said means have at least one control valve (9, 37) which is disposed in a line (10) for pressurised water, which line leads to the water outlet nozzle (7) of which there is at least one, and wherein the means for controlling the quantity of water have at least one electrical or electronic control arrangement (11) for controlling the control valve (9, 37), of which there is at least one, and there is associated with the said means a sensor arrangement (21) which has a first temperature sensor (22) for ascertaining the actual air temperature, characterised in that the first temperature sensor (22) and a second temperature sensor (23) of the sensor arrangement (21) are disposed, at least with their active region (22', 23') in each case, in the flow of air through the air duct or in a flow of air proportional thereto, that means (25, 27) are provided in order to constantly wet, or keep moist, with a liquid the active region (23') of the first of the temperature sensors (22, 23), of which there are at least two, and that the quantity of water given off into the flow of air is controlled by regulation of the control valve (9, 37), of which there is at least one, by the control arrangement (11) while taking into account the difference between the temperatures ascertained by the two temperature sensors (22, 23).
2. Snow cannon according to claim 1, characterised in that the at least two temperature sensors (22, 23) are arranged on an opening (24), through which at least a part of the flow of air through the air duct passes, and/or that the at least tow temperature sensores (22, 23) of the sensor arrangement (21) are arrange near the input side of the air duct, where air is drawn into the air duct.
3. Snow cannon according to one of claims 1 to 2, characterised in that the temperature sensors (22, 23), of which there are at least two, of the sensor arrangement (21) are disposed before the blower (4), referred to the direction of flow.
4. Snow cannon according to one of claims 1 to 3, characterised in that the temperature sensors (22, 23), of which there are at least two, of the sensor arrangement (21) are disposed with their active regions (22', 23') side by side and at the same height in the flow of air.
5. Snow cannon according to one of claims 1 to 4, characterised in that the means for keeping the active region (23') of the second temperature sensor (23) moist are constituted by a wick-like element, for example a fabric hose (25), which is secured by one of its ends to the active region (23') of the first temperature sensor (23), and is in communication, by its other end, with the interior of a container (27) for receiving a liquid.
6. Snow cannon according to one of claims 1 to 5, characterised in that the liquid is a mixture of water and an antifreeze agent.
7. Snow cannon according to one of claims 1 to 6, characterised in that the quantity of water introduced into the flow of air (8) passing out is regulated in dependence upon, or while taking into account, the difference in temperature between the two temperature sensors (22, 23), of which there are at least two, of the sensor arrangement (21), and also while taking into account the actual temperature ascertained by the second, dry temperature sensor (22).
8. Snow cannon according to one of claims 1 to 7, characterised in that the quantity of water introduced into the flow of air (8) passing out is controlled while taking into account further parameters, in particular while taking into account the water temperature measured by a further temperature sensor (16) and/or the snow quality preselected at an adjusting element (18).
9. Snow cannon according to one of claims 1 to 8, characterised in that the control valve, of which there is at least one, is a proportional valve (37).
10. Snow cannon according to one of claims 1 to 9, characterised by a valve arrangement which has a number of control valves (9) and with which a corresponding number of water outlet valves (7) can be activated in dependence upon the quantity of water to be introduced into the flow of air (8) passing out.
11. Snow cannon according to one of claims 1 to 10, characterised in that the control arrangement (11) has at least one connection or interface for outputting and/or inputting data, with which connection or interface the control arrangement can be connected to a control and monitoring unit (31) which is common to a number of snow cannons or their control arrangements.
12. Snow cannon according to one of claims 1 to 11, characterised by a valve arrangement (34) which controls the water feed and can be switched at least into a first condition that connects the snow cannon (1a) to a water supply line (33) laid in a frost-resistant manner, and also into a condition that empties the snow cannon or the lines conducting water at that point.
13. Snow cannon according to one of claims 1 to 12, characterised in that the water outlet nozzle (7), of which there is at least one, and/or the control valve (9, 37), of which there is at least one, and/or water-conducting lines (5, 10) of the snow cannon (1, 1a) can be heated.

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