Abstract:
The present invention provides a method for making snow. The method includes discharging a supply of pressurized water in ambient air, discharging a supply of pressurized air in ambient air, and controlling the discharge of the supply of pressurized water and/or the discharge of the supply of pressurized air to regulate a ratio of water to air, to more efficiently make snow over a range of ambient temperatures.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims benefit to U.S. Provisional application Ser. No. 60/174,753, filed Jan. 6, 2000. 
    
    
     TECHNICAL FIELD 
     The present invention generally relates to artificial snow making, and more particularly, to methods and devices for making snow. 
     BACKGROUND OF THE INVENTION 
     In general, artificial snow-making involves atomizing a spray of water with a jet of air to create a plume of very fine water droplets which nucleate and form snow as the plume drops to earth under freezing temperature conditions. Water and air may be brought separately up a tower in inner and outer, concentric, spaced apart conduits. The air may flow through the inner conduit passageway and the water through the annular passageway formed between the conduits. As a result, the water stream functions to insulate the air stream. 
     The water stream is supplied under pressure to a point of discharge above ground level and adjacent to a top end of a tower where it is discharged through a nozzle into the ambient freezing atmosphere in the form of the spray. The spray is preferably a high velocity spray of discrete water particles. Air is also supplied under pressure to a second point of discharge at the top of the tower where it is discharged through an orifice to form a jet of air which is directed into the water spray thereby forming a plume of atomized or nucleated water. This atomized water forms seed crystals in a freezing atmosphere, and through the dwell time of the long fall from the top of the tower to the ground, forms snow. 
     One drawback to this type of system is that snow can only be made at specific ambient temperature conditions for a given pressurized water supply and a given pressurized air supply. When the ambient temperature changes from the specific ambient temperature the system operates with decreased efficiency of does not operate at all to produce snow. 
     Therefore, a need exists for snow making methods and devices to efficiently make snow over a range of ambient temperature conditions. 
     SUMMARY OF THE INVENTION 
     The present invention provides, in a first aspect, a method for making snow over a range of ambient temperatures in which the method includes discharging a supply of pressurized water in ambient air, discharging a supply of pressurized air into the discharged supply of pressurized water, and controlling the discharge of the supply of the pressurized water and/or the supply of the pressurized air to control a ratio of water to air. 
     The present invention provides, in a second aspect, a method for making snow. The method includes providing a discharge unit having a plurality of fluid discharge nozzles, and controlling discharge of a supply of pressurized water and a supply of pressurized air from the plurality of fluid discharge nozzles. 
     The present invention provides, in a third aspect, a device for making snow. The device includes a discharge unit having a plurality of discharge nozzles and a control mechanism for controlling a supply of pressurized water and a supply of pressurized air to the plurality of discharge nozzles. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention will be readily understood from the following detailed description of various embodiments taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a perspective view of a first embodiment of a snow making device according to the present invention; 
     FIG. 2 is an enlarged perspective view of the discharge unit and the fluid flow control mechanism of the snow making device shown in FIG. 1; 
     FIG. 3 is an enlarged perspective view of the discharge unit of the snow making device of FIG. 1; 
     FIG. 4 is an enlarged cross-sectional view taken along line  4 — 4  of FIG. 2; 
     FIG. 5 is an enlarged cross-sectional view taken along line  5 — 5  of FIG. 2; 
     FIG. 6 is a cross-sectional view taken along line  6 — 6  of FIG. 5; 
     FIG. 7 is a cross-sectional view taken along line  7 — 7  of FIG. 5; 
     FIG. 8 is a cross-sectional view taken along line  8 — 8  of FIG. 5; 
     FIG. 9 is a cross-sectional view taken along line  9 — 9  of FIG. 5; 
     FIG. 10 is a cross-sectional view taken along line  10 — 10  of FIG. 5; 
     FIG. 11 is a perspective view of a control unit of the snow making of FIG. 1; 
     FIG. 12 is a cross-sectional view taken along line  12 — 12  of FIG. 11; 
     FIG. 13 is a perspective view of another embodiment of a discharge unit according to the present invention; 
     FIG. 14 is an end view of the discharge unit of FIG. 13; 
     FIG. 15 is another embodiment of a snow making device according to the present invention; 
     FIG. 16 is an enlarged cross-sectional view taken along line  16 — 16  of FIG. 1; and 
     FIG. 17 is an enlarged cross-sectional view taken along line  17 — 17  of FIG.  15 . 
    
    
     DETAILED DESCRIPTION 
     In accordance with one embodiment of the present invention, a method for making snow is provided. The method includes discharging a supply of pressurized water in ambient air, discharging a supply of pressurized air into the discharged supply of pressurized water, and controlling the discharge of the supply of the pressurized water and/or the discharge of the supply of the pressurized air, based on ambient temperature. 
     For example, it is desirable to produce a maximum amount of snow for a given ambient air temperature. In order to maximize efficiency of a snow making system, it is preferable to have an adequate water to air ratio for a given ambient air temperature. When ambient air temperatures are above approximately 26 degrees Fahrenheit it may be necessary to provide a relatively large quantity of air to a relatively small quantity of water. However, when ambient air temperatures are below approximately 26 degrees Fahrenheit it is desirable to provide a relatively large quantity of water to a relatively small quantity of air. An adequate air to water ratio allows qualities of snow to be produced at varying ambient air temperatures. By maximizing the amount of snow which can be produced, the overall efficiency of the system is increased while the operating costs of the system are lowered. 
     One example of a snow making device  10  incorporating and using the capabilities of the present invention is described with reference to FIG.  1 . Snow making device  10  generally includes a discharge unit  12  connected to a fluid flow control mechanism  18  connected to a conduit  16  and to a control unit  14 . Snow making device  10  may be secured to a support structure (not shown) in such a manner as to allow an operator to rotate and/or pivot the device to control the direction of fluid discharge. Snow making device  10  may be positioned along a ski slope adjacent to a ski trail. The components of snow making device  10  may be constructed out of stainless-steel, aluminum alloy or any other suitable material as may be known by those skilled in the art. 
     As best shown in FIG. 2, discharge unit  12  is mounted on fluid flow control mechanism  18  at flanged connection  20 . Fluid flow control mechanism  18  is mounted on the upper end of fluid conduit  16  by a flanged connection  22 . 
     With reference to FIG. 3, discharge unit  12  comprises a plurality of air discharge nozzles  24 , and a plurality of water discharge nozzles  26 . In this illustrated embodiment discharge unit  12  includes six water discharge nozzles  26 ,  30  and  34 , and ten air discharge nozzles  24 ,  28 , and  32  (only 7 of which are shown) however the placement and/or number of air and water discharge nozzles may be increased or decreased based upon design specifications. Also the shape of discharge unit  12  may be varied from the illustrated design, for example a single elongated tube may comprise a plurality of air and water discharge nozzles, or other shapes and/or designs may be used as is known in the art. 
     Air discharge nozzles  24  and water discharge nozzles  26  are referred to as the primary air and water discharge nozzles. Also mounted on discharge unit  12  are a first supplemental air nozzle  28 , a first supplemental water nozzle  30 , a second supplemental air nozzle  32 , and a second supplemental water nozzle  34 . Supply of air and water to each of the air and/or water nozzles may be individually controlled and regulated by an operator using control unit  14  (FIG. 1) to manipulate the inlets and outlets of fluid flow control mechanism  18  (FIG.  1 ). 
     Referring again to FIGS. 1 and 2, air and water are supplied to fluid flow control mechanism  18  by fluid conduit  16 . As best shown in FIG. 16, fluid conduit  16  desirably has an inner fluid conduit  19  which supplies air, and an outer fluid conduit  21  which supplies water. Through such an arrangement an outer conduit  21  acts as an insulator of inner conduit  19 . Also, inner fluid conduit  19  and outer fluid conduit  21  may be offset to one side of fluid conduit  16  to provide space for other components. Alternatively, a conduit system using a pair of separated conduits supplying air and water may be used, or any other system, as may be known by those skilled in the art. 
     Now referring to FIG. 4, fluid flow control mechanism  18  has a plurality of fluid inlet holes  36  and an air inlet  38 , located on the lower end. Air inlet  38  is in fluid flow communication with inner air conduit  19  (FIG.  16 ), which supplies pressurized air to discharge unit  12 . Similarly, fluid inlet holes  36  are in fluid flow communication with outer fluid conduit  21  (FIG.  16 ), which supplies a fluid, such as water, to discharge unit  12 . As illustrated in FIG. 5, a plurality of air and fluid outlets are depicted which supply air and fluid to discharge unit  12 . The flow of air and fluid to discharge unit  12  is controlled and regulated by fluid flow control mechanism  18 . 
     The inner valve system of fluid flow control mechanism  18  is illustrated in FIGS. 6-10. A rod  40  is manipulated by use of control unit  14  (FIG.  1 ), e.g. by turning the handle. Manipulation of rod  40  causes a series of valves  42  to open and close, causing fluid to enter flow chambers  44  which are in fluid flow communication with a series of air and fluid conduits  46  which supply air and/or fluid to a respective air and/or fluid discharge nozzle(s). By opening and closing valves  42  different fluid flow configurations are provided for use in various ambient air temperatures. 
     Referring to FIGS. 11 and 12, rod  40  is manipulated by movement of a handle  50  of control unit  14 . Handle  50  may be pulled out to lock in different positions by an operator, with each position opening and/or closing successive valves which corresponds to different fluid flow configurations. Alternatively, handle  50  may be rotated to drive a worm gear (not shown) which in turn moves a rod and thereby opens and closes the valves. Control unit  14  is mounted on the lower end of fluid conduit  16  (FIG. 1) at flanged connection  52 . A fluid, such as water, is supplied to the system at fluid inlet  54 . Similarly, air may be supplied to the system at air inlet  55  (FIG.  1 ). 
     As would be understood by one skilled in the art, rod  40  and/or handle  50  of control unit  14  might be controlled by an automatic or automated controlling assembly (not shown) coupled to a controller (not shown), for example, a microprocessor. Such a controller might also be coupled to a temperature sensor (not shown) which might allow the controller to automatically control rod  40  and/or handle  50  of control unit  14  based on the ambient temperature. Also, handle  50  might be marked to indicate to a user different positions of handle  50  corresponding to different ambient temperature conditions, thus facilitating manual manipulation to these positions based on ambient temperature conditions. 
     With reference to FIG. 12, control unit  14  is configured with a check valve  56  (FIG. 11) that enables fluid to drain from the system. When the fluid is no longer supplied to the system, the resulting pressure drop opens check valve  56  and fluid is allowed to drain from the system. Check valve  56  is preferably a spring and ball check valve, however any other suitable check valve as may be known in the art may be used. Also, when the system pressure drops, spring  58  moves assembly  60 , which retracts rod  40  and opens all of the valves to a position which allows drainage of discharge unit  12  (FIG. 1) and fluid flow control mechanism  18  (FIG. 1) through fluid outlets  62 . This safety feature provides for complete, automatic drainage of the device when it is not in use and thereby reduces a risk of a fluid, for example water, freezing inside the device and causing damage thereto. 
     As would be evident to those skilled in the art from the above description, discharge unit  12  may be provided in various locations, for example, on a snow making tower or on a chair lift support. Also control mechanism  18  and portions thereof may be located at a distance from discharge unit  12 , for example, at a bottom of a snow making tower or pole, or a plurality of control mechanisms  18  or portions thereof might be provided in a central location. 
     FIGS. 13 and 14 illustrate a second embodiment of a discharge unit  100  according to the present invention. Discharge unit  100  may be attached to fluid flow control mechanism  18  (FIG.  1 ). Arranged circumferentially around discharge unit  100  are a plurality of primary water nozzles  110 , a plurality of secondary water nozzles  115 , a plurality of primary air discharge nozzles  120 , and a plurality of secondary air discharge nozzles  125 . Primary water nozzles  110  may be in constant fluid communication with a source of water and primary air discharge nozzles  120  may be in constant fluid communication with a source of air when the device is in operation, for example, in fluid communication with outer fluid conduit  21  and inner fluid conduit  19 , respectively. These water and air conduits are in fluid communication with sources of water and air, respectively, preferably, pressurized sources thereof. Secondary water nozzles  115  and secondary air nozzles  125  may be connected to fluid flow control mechanism  18  which may allow one or several of these nozzles to be selected for use at a given time depending on ambient temperature conditions. 
     For example, discharge unit  100  may include four primary water discharge nozzles  110 , four secondary water discharge nozzles  115 , four primary air discharge nozzles  120 , and twelve secondary air discharge nozzles  125 . Several of the air and water discharge nozzles may be connected to fluid flow control mechanism  18  while several may bypass fluid flow control mechanism  18  and may be in constant communication with a source of fluid and/or air. This allows some of the nozzles to be selectable by a user depending on ambient temperature conditions while the others are beyond the user&#39;s selection and thus utilized wherever discharge unit  100  is in operation. For example, four of water discharge nozzles  110  and four of air discharge nozzles  120  may be in constant fluid connection with outer fluid conduit  21  and inner fluid conduit  19 , respectively, of fluid conduit  16 . 
     FIGS. 15 and 17 illustrate another embodiment of a snow making device  130  according to the present invention. The snow making device includes a discharge unit  165  connected to a fluid conduit  170  which may be connected to a regulator  175 , for example, a ball valve. Fluid conduit  170  may include a water conduit  180 , a primary air conduit  185 , and a secondary air conduit  190 , as illustrated in FIG.  17 . Primary air conduit  185  and secondary air conduit  190  may be inner conduits contained by water conduit  180 . Water conduit  180  may be in communication with a source of water and primary air conduit  185  and secondary air conduit  190  may be in fluid communication with a source of air. Preferably, water conduit  180  is in direct fluid communication with a pressurized source of water, while primary air conduit  185  and secondary air conduit  190  are connected to regulator  175  which is fluid communication with a source of pressurized air. Also, primary air conduit  185  and secondary air conduit  190  may be of different diameters, thus allowing regulation of air flow per unit time and air pressure by selecting therebetween. 
     As shown in FIG. 15, discharge unit  165  includes, for example, two water discharge nozzles  150  (only one of which is shown in FIG. 15) and six air discharge nozzles  160  (only three of which are shown in FIG. 15) distributed thereon. Water discharge nozzles  150  and may be in constant fluid communication with the source of water, when snow making device  130  is in use. Two primary air discharge nozzles  163  of air discharge nozzles  160  and four secondary air discharge nozzles  167  of air discharge nozzles  160  may be operatively connected to regulator  175 , thus allowing the user to turn a handle  177  to a first position and provide fluid communication between primary air conduit  185  and primary air discharge nozzles  163 . Alternatively, the user may turn handle  177  to a second position, further causing fluid communication between secondary air discharge nozzles  167  and secondary air conduit  190 . Further, the user may turn handle  177  to a third position to cause fluid communication between only secondary air discharge nozzles  167  and secondary air conduit  190 . 
     When it is desired to manufacture snow using the present invention, the water and air inlets may be connected to pressurized water and air supply conduits. Returning to FIG. 1, water and air then flow through control unit  14 , fluid supply conduit  16  and into fluid flow control mechanism  18  for distribution to and discharge from discharge unit  12 . 
     One example of a system and method regulating the air and water ratio is described as follows. Referring to FIG.  6  and FIG. 11, when it is desired to have a high air to water ratio, an operator may adjust handle  50  of control unit  14  to a first position which in turn moves rod  40  to a position which opens and/or closes the appropriate valves to allow water discharge from the primary water discharge nozzles  26  (FIG.  3 ), and air discharge from the primary air discharge nozzles  24  (FIG.  3 ). As can be seen in FIG. 3, there are eight primary air discharge nozzles  24  and four primary water discharge nozzles  26 . This provides a high air to water ratio allowing quality snow manufacture at elevated ambient air temperatures, for example at about 28 degrees Fahrenheit. 
     Referring to FIG. 7, if the ambient air temperature lowers, for example to about 25 degrees Fahrenheit, an operator may adjust handle  50  (FIG. 11) of control unit  14  (FIG. 11) to a second position, which in turn moves rod  40  to a position which opens and/or closes the appropriate valves to allow water discharge from the primary water discharge nozzles  26  (FIG.  3 ), and air discharge from six of the eight air discharge nozzles  24  (FIG.  3 ). This second position provides a reduced air to water ratio compared to the configuration shown in FIG.  6 . 
     Referring to FIG. 8, if the ambient air temperature lowers further, for example to about 22 degrees Fahrenheit, an operator may adjust handle  50  (FIG. 11) of control unit  14  (FIG. 11) to a third position, which in turn moves rod  40  to a position which opens and/or closes the appropriate valves to allow water discharge from the primary water discharge nozzles  26  (FIG.  3 ), and air discharge from four of the eight air discharge nozzles  24  (FIG.  3 ). This third position provides a reduced air to water ratio compared to the configuration shown in FIG.  7 . 
     Referring to FIG. 9, if the ambient air temperature was to lower further, for example to an ambient temperature of about 20 degrees Fahrenheit, an operator may adjust handle  50  (FIG. 11) of control unit  14  (FIG. 11) to a fourth position, which in turn moves rod  40  to the position which opens and/or closes the appropriate valves to allow water discharge from first supplemental water discharge nozzle  30 , and air discharge from first supplemental air discharge nozzle  28  as well as from the primary air and water discharge nozzles (third position). This allows an increased amount of water to be discharged, thus producing an increased amount of snow. 
     In optimal snow manufacturing conditions, for example at a temperature of about 18 degrees Fahrenheit, it may be desired to increase the amount of snow being produced. Therefore during such conditions, referring to FIG. 10, an operator may further adjust handle  50  (FIG. 11) of control unit  14  (FIG. 11) to a fifth position, which in turn moves rod  40  to the position which opens and/or closes the appropriate valves to allow water discharge from second supplemental water discharge nozzle  34  (FIG.  3 ), and air discharge from second supplemental air discharge nozzle  32  (FIG. 3) as well as from the air and water discharge nozzles of the fourth position. This allows a maximum amount of water to be discharged, thus producing a maximum amount of snow. It will be evident to those skilled in the art that optimal snow making conditions may depend on various factors including air temperature, water temperature and relative humidity. 
     Another example of a system and method which regulates an air and a water ratio which utilizes discharge unit  100  is described as follows. Referring to FIG.  6  and FIG. 11, when it is desired to have a high air to water ratio, for example at a temperature of about 28 degrees Fahrenheit, an operator may adjust handle  50  of control unit  14  to a first position which in turn moves rod  40  to a position which opens and/or closes the appropriate valves to allow water discharge from primary water discharge nozzles  110  (FIG.  14 ), and air discharge from primary air discharge nozzles  120  (FIG. 14) and secondary air discharge nozzles  125 . This provides a high air to water ratio allowing quality snow manufacture at elevated ambient air temperatures. As can be seen in FIGS. 13 and 14, there are four primary air discharge nozzles  120  (only two of which are shown), twelve secondary air discharge nozzles  125  (only six of which are shown), four primary water discharge nozzles  110 , and four secondary water discharge nozzles  115 . 
     Referring to FIG. 7, if the ambient air temperature lowers, to about 22 degrees Fahrenheit for example, an operator may adjust handle  50  (FIG. 11) of control unit  14  to a second position, which in turn moves rod  40  to a position which opens and/or closes the appropriate valves to allow water discharge from primary water discharge nozzles  110  (FIG.  13 ), and air discharge from primary air discharge nozzles  120  and four secondary air discharge nozzles  125 . This second position provides a reduced air to water ratio as compared to the configuration shown in FIG.  6 . 
     Referring to FIG. 8, if the ambient air temperature lowers further, to about 22 degrees Fahrenheit for example, an operator may adjust handle  50  (FIG. 11) of control unit  14  (FIG. 11) to a third position, which in turn moves rod  40  to a position which opens and/or closes the appropriate valves to allow water discharge from primary water discharge nozzles  110  (FIG.  13 ), and air discharge from primary air discharge nozzles  120  (FIG.  13 ). 
     Referring to FIG. 9, if the ambient air temperature was to lower further, for example to a temperature of about 20 degrees Fahrenheit, an operator may adjust handle  50  (FIG. 11) of control unit  14  (FIG. 11) to a fourth position, which in turn moves rod  40  to the position which opens and/or closes the appropriate valves to allow water discharge from two secondary water discharge nozzles  115  (FIG.  13 ), and air discharge from two supplemental air discharge nozzles  125  (FIG.  13 ), as well as air and water discharge from primary air discharge nozzles  120  (FIG. 13) and primary water discharge nozzles  110  (FIG.  13 ), respectively. 
     In optimal snow manufacturing conditions, for example at a temperature of about 15 degrees Fahrenheit, it may be desired to increase the amount of snow being produced. Therefore, during such conditions, referring to FIG. 10, an operator may further adjust handle  50  (FIG. 11) of control unit  14  (FIG. 11) to a fifth position which in turn moves rod  40  to the position which opens and/or closes the appropriate valves to allow water discharge from primary water discharge nozzles  110  (FIG. 13) and four secondary water discharge nozzles  115 , and air discharge from primary air discharge nozzles  120  (FIG. 3) as well as from four secondary air discharge nozzles  125 . This allows a maximum amount of water to be discharged, thus producing a maximum amount of snow. 
     A further example of a system, illustrated in FIG. 15, and method which regulates an air to water ratio is described as follows. When snow making device  130  is in use, primary water conduit  180  (FIG. 17) is in fluid communication with a source of water and water discharge nozzles  150 . Also, primary air conduit  185  (FIG. 17) may be in fluid communication with a source of air and primary air discharge nozzles  163  when handle  180  connected to regulator  175  is in a first position. In the event of a temperature rise to about 28 degrees Fahrenheit, for example, an operator may adjust the regulator from a first position to a second position by turning handle  180  to cause secondary air conduit  190  to be in fluid communication with secondary air discharge nozzles  167  and a supply of air. This allows air discharge from primary air discharge nozzles  163  and additionally from secondary air discharge nozzles  167 . The operator might further adjust handle  180  to a third position to cause only secondary air conduit  190  to be in fluid communication with secondary air discharge nozzles  167 . 
     The examples described herein are just examples. There may be many variations to the method and/or device described therein without departing from the spirit of the invention. For instance, the operational steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention. 
     Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.