1. Technical Field
The present invention relates to devices for making artificial snow, in particular, to devices which use water and air to form and project snow over outdoor areas, such as ski slopes.
2. Background Information
For a number of years it has been the practice to employ equipment to deposit artificially made snow on outdoor surfaces, such as ski slopes, when nature does not provide the desired quantity of snow. A variety of mechanical devices have been employed. Generally, the approach is to take water droplets and convert them to frozen particles. Prior art devices typically break up a stream of water by means of pressure atomizing and or two-fluid (air-water) atomizing. Often fans are used to provide an airstream which entrains the droplets as they become frozen, and better to carry them through space and deposit them across a wide area.
There are various problems and limitations connected with prior art snow making devices. They include complexity, noise, reliability, weight, difficult maneuverability, low efficiency in covering a desired area, poor ability for making snow at comparatively warm temperatures, high initial cost, and high operating cost.
According to a first aspect of the invention, a snow making apparatus is provided that includes a manifold, a nucleator annular chamber, and a plurality of nucleator nozzles. The manifold is configured to receive water from a water source and configured to receive air from an air source. The nucleator annular chamber is configured to receive an air-water mixture from first passages, which first passages are oriented to direct the air-water mixture tangentially into the nucleator annular chamber for subsequent circumferential and axial travel within the annular chamber. The plurality of nucleator nozzles is positioned to receive the air-water mixture from the nucleator annular chamber. The nucleator nozzles are configured to allow the air-water mixture to exit the apparatus through the nozzles.
According to another aspect of the present invention, a snow making apparatus is provided that includes a manifold, a nucleator mix nozzle, a primary nozzle, an annular cavity, and a filter. The manifold is configured to receive water from a water source and configured to receive air from an air source. The annular cavity is disposed downstream of the manifold, configured to receive the water from the manifold. The filter has an aft end. The filter is configured to receive a portion of the water traveling through the annular cavity, which portion is directed to travel through the nucleator mix nozzle. The remaining portion of the water traveling through the annular cavity is directed to exit the apparatus through the primary nozzle.
According to another aspect of the present invention, a snow making apparatus is provided that includes a manifold, a first ring, a second ring, a primary nozzle, a nucleator mix nozzle, and a nucleator annular chamber. The manifold is configured to receive water from a water source and configured to receive air from an air source. The first ring has a plurality of water passages positioned to receive the water from the manifold. The second ring has a plurality of nucleator nozzles. The primary nozzle is attached to a primary nozzle ring. The nucleator annular chamber is configured to receive an air-water mixture from first passages disposed in the second ring, which first passages are oriented to direct the air-water mixture tangentially into the nucleator annular chamber for subsequent circumferential and axial travel within the annular chamber. The nucleator nozzles are positioned to receive the air-water mixture from the nucleator annular chamber. The nucleator nozzles are configured to allow the air-water mixture to exit the apparatus through the nozzles.
In one or more of the aspects of the snow making apparatus described above, the nucleator annular chamber and first passages are configured to cause the air-water mixture circumferentially and axially traveling within the nucleator annular chamber to experience centrifugal forces sufficient to overcome gravitational forces during normal operating conditions.
The foregoing and other objects, features and advantages of the invention will become more apparent from the following description of preferred embodiments and accompanying drawings.
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The hub 76 is disposed contiguous with the metering nozzle cavity 72. A first passage 96 extends through the hub 76, permitting fluid (e.g., water) passage through the nucleator swirl ring 24. The hub 76 includes a first outer diameter surface 98, a second outer diameter surface 100, and a radial surface 102 extending between the first and second outer diameter surfaces 98, 100. The diameter of the first outer diameter surface 98 is greater than the diameter of the second outer diameter surface 100.
A plurality of axial passages 104 extend between the flow channels 74 and the cavity 78, permitting fluid (e.g., water) flow through the nucleator swirl ring 24. In the embodiment shown in
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The nucleator nozzle ring 26 further includes a first outer diameter surface 132, a radially extending flange 134, a second outer diameter surface 136, and a plurality of nucleator nozzles 138. A channel 140 for receiving an O-ring is disposed in the first outer diameter surface 132. In the embodiment shown in
The nucleator nozzle ring 26 further includes a plurality of swirl passages 142 disposed in the first end surface 112, spaced apart from one another around the circumference of the first end surface 112. Each swirl passage 142 has length that extends along an axis that is disposed at an angle “α” relative to a radial centerline of the nozzle ring. As will be explained below, the angle “α” is such that water passing through the passages 142 in the direction from the first outer diameter surface 132 toward the first cavity 116 enters the first cavity tangentially. As a result, the water is directed to travel (i.e., “swirl”) around the circumference of the first cavity 116.
In a preferred embodiment, the nucleator nozzle ring 26 includes a rib 144 disposed at the first end surface edge of the first cavity 116, which rib 144 extends a distance radially inwardly.
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The present snowgun 20 may be assembled in a number of different ways, and is not limited to any particular manner As indicated above, one or more of the elements of the present snowgun 20 may be combined into unitary elements and still be within the scope of the present invention. To illustrate how the snowgun may be assembled in a non-limiting example, the following description is offered.
As can be seen from the FIGURES, when the snowgun 20 is assembled, a portion of the second outer diameter surface 90 of the nucleator swirl ring 24 is received within the first and second cavities 116, 118 of the nucleator nozzle ring 26. The nucleator swirl ring 24 and the nucleator nozzle ring 26 may be joined together by weld, for example.
As described above, the intermediary ring 32, the nucleator nozzle ring 26, and the primary nozzle ring 34 may have mating lap joints. At each lap joint the respective pieces may be welded together. It can be seen, therefore, that the nucleator swirl ring 24, the nucleator nozzle ring 26, the intermediary ring 32, and the primary nozzle ring 34 may be joined together as a unitary piece.
The nucleator metering nozzle 30 may be attached to the hub 76 of the nucleator swirl ring 24 by, for example, screw thread.
The swirl sleeve 28 may be slid over the first outer diameter surfaces 88, 132 of the nucleator swirl ring 24 and the nucleator nozzle ring 26, respectively. The fluid inlet manifold 22 may then be screwed into the nucleator swirl ring 24. The flanges 54, 134 of fluid inlet manifold 22 and the nucleator nozzle ring 26 hold the swirl sleeve 28 in place. As can be seen in
The internal flow sleeve 40 may be inserted through the primary nozzle ring 34 and into the intermediary ring 32 a distance sufficient to allow the first and second outer diameter surfaces 88, 90 of the hub 76 to be received within the internal flow sleeve 40. The second end surface 186 of the internal flow sleeve 40 is slid into contact with the base of the cavity 78 of the nucleator swirl ring 24. As indicated above, the inner diameter 188 of the internal flow sleeve 40 may be sized to form a slight interference fit with the first outer diameter surface 98 of the hub 76 to keep the internal flow sleeve 40 attached to the nucleator swirl ring 24.
The water filter 42 may be inserted through the primary nozzle ring 34 and into the intermediary ring 32 a distance sufficient to allow the second outer diameter surface 100 of the hub 76 to be received within the water filter 42. The second end 208 of the water filter 42 is slid into contact with the first radial surface 102 of the hub 76. The inner diameter 200 of the water filter 42 may be sized to form a tight slid fit or a slight interference fit with the second outer diameter surface 100 of the hub 76 to keep the water filter 42 attached to the nucleator swirl ring 24.
The end cap 38 may be attached to the flow elements of the primary nozzle 36; e.g., by weld.
The primary nozzle 36 (with the end cap 38 attached) may then be inserted into the primary nozzle ring 34. As the nozzle/end cap assembly is slid into the primary nozzle ring 34, the end cap 38 will extend into the intermediary ring 32, and the second end of the water filter 42 will engage an 0-ring 220 disposed in the first end surface channel 178 of the end cap 38. The primary nozzle/end cap assembly can be secured to the primary nozzle ring 34 by screwing the nozzle 36 and the nozzle ring 34 together. An O-ring 224 seals between the primary nozzle 36 and the primary nozzle ring 34.
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As indicated above, in a preferred embodiment, the axial passages 104 are disposed at a tangential angle (e.g., in the range of 15-20 degrees) relative to the central axis 44 to direct water exiting the axial passages 104 to travel both circumferentially and axially; i.e., a direction that causes the water to circumferentially “swirl” (e.g., diagrammatically shown in
The water exits the cavity 78 and enters the annular flow passage 198 formed between the internal flow sleeve 40 and the intermediary ring 32. A portion of the water then travels through the passage 197 formed between the second end surface 196 of the internal flow sleeve 40 and the first end surface 174 of the end cap 38, through the water filter 42, and into the internal cavity 210 of the water filter 42. Once in the internal cavity 210, the water travels toward and through the nucleator metering nozzle 30. As indicated above, the apertures in the water filter 42 are smaller in diameter than the nucleator metering nozzle orifice to decrease the possibility of the nucleator metering nozzle orifice getting clogged. Water used for snow making purposes is often drawn from a natural source (e.g., a stream or pond) and consequently often contains debris from the source or debris (e.g., rust) from the piping supplying the water to the snowgun. Hence, the filter 42 increases the operational reliability of the snowgun 20. In addition, the internal flow sleeve 40 creates a desirable fluid flow path internally within the snowgun 20. Specifically, the internal flow sleeve 40 forces the water flow within the annular flow passage 198 to travel substantially all of the passage 198. As a result, the water travels within the passage 198 provides desirable heat transfer relative to the intermediary ring 32. In addition, in the absence of the internal flow sleeve 40, a pressure gradient within the annular flow passage 198 can cause undesirable recirculating flow patterns; e.g., water flow entering the filter 42 proximate the end cap 38 may travel within the internal cavity 210 of the filter 42 and exit the cavity 210 and enter back into the annular flow passage 198 proximate the nucleator swirl ring hub 76.
The remainder of the water flow through the annular flow passage 198 (i.e., the portion of the water that does not enter the water filter 42) travels past the end cap 38 and enters the primary nozzle 36 via the tangential flow passages between the flow elements 164. From there the water exits the primary nozzle 36 in a defined conical geometry and into the atmosphere.
At the same time the water is passing through the snowgun, air (depicted as a dotted line) at an elevated pressure (e.g., in the range of 40-100 psig) and flow rate (e.g., in the range of 20-40 scfm) is directed into the centrally located air passage 50 within the fluid inlet manifold 22, through the manifold 22 and into the metering nozzle cavity 72. At this point the air mixes with the water passing through the nucleator metering nozzle 30 (air-water mixture is depicted as a dash dot dash line) and is directed out of the metering nozzle cavity 72 via the radial passages 106 extending between the metering nozzle cavity 72 and the respective angled passage 108 (e.g., see
An example of flows within the swirl chamber 110 could be 30 cubic feet per minute (cfm) air with 0.5 gallons per minute (gpm) water; i.e., an air/water (“A/W”) ratio of sixty (60). In this example, the air in the swirl chamber 110 may be swirling at a velocity of about 100 feet per second, and water film on the radially outer surface at about 20 feet per second. The gravitational forces (i.e., “G” forces) may be on the order of 125 G's, assuring a uniform layer of water disposed on the outer periphery.
To illustrate the significance of the present snowgun 20 design, consider the operation of a prior art snowgun. Most snowguns are attached to long stands that position the snowgun many feet above the surface to be covered with snow—the higher the snowgun, the greater potential reach of the snowgun and the greater the distance the snowgun produced mixture must travel before reaching the ground. The quality of the snow made by the snowgun typically increases with the amount of time the mixture is airborne. In many prior art snowguns, it is not uncommon for ice to build up on the snowgun during operation. If enough ice builds up, the snowgun can freeze and stop producing snow. Once the snowgun stops flowing, any water within the piping leading to the snowgun becomes static and susceptible to freezing and potentially rupturing the piping. The present snowgun 20 design addresses this issue, for example, by heat transfer to the snowgun 20 from the air-water mixture swirling with swirl chamber 110, thereby inhibiting ice formation on the exterior of the snowgun 20.
The air-water mixture traveling circumferentially within the swirl chamber 110 also travels axially, and encounters the plurality of swirl passages 142 disposed in the first end surface 112 of the nucleator nozzle ring 26. The orientation of the swirl passages 142 (e.g., the swirl passage length extending along an axis that is disposed at an angle “a” relative to a radial centerline of the nozzle ring) enables the air-water mixture circumferentially traveling within the swirl chamber 110 to readily exit the swirl chamber 110 in a tangential manner. The air-water mixture travels through the swirl passages 142 (in a direction that is in part radially inward) and enters a nucleator annular chamber 222 formed between the second outer diameter surface 90 of the nucleator swirl ring 24 and the first inner diameter surface 124 of the first cavity 116 of the nucleator nozzle ring 26. Once the air-water mixture is within the nucleator annular chamber 222, the mixture travels circumferentially and axially, and subsequently passes out through the nucleator nozzles 138. In the preferred embodiment that includes a rib 144 disposed at the first end surface edge of the first cavity 116, the rib 144 helps to maintain the air-water mixture within the nucleator annular chamber 222. The “swirling” (i.e., circumferential travel at a high velocity) of the air-water mix within the nucleator annular chamber 222 provides several advantages. First the swirling provides a uniform distribution of air-water mixture to the nucleator nozzles 138. Second, the centrifugal forces acting on the swirling the air-water mixture are also strong enough to overcome gravitational forces acting on the air-water mixture. In operation, snowguns may be positioned in a variety of different orientations. Most of these orientations are such that gravitational forces will, in the absence of the swirl, cause water to collect in the vertically lower portion of the nucleator (the gravitational vector being vertical), thereby negatively influencing the uniformity of the air-water mixture being dispersed through the nucleator nozzles around the circumference of the gun. The swirling flow within the present snowgun 20 solves this problem.
The air-water mixture exiting the nucleator nozzles 138 forms a conical shaped body of air-water mixture. The geometry of the conical shaped body is a function in part of the angle “σ” at which the nucleator nozzles 138 are disposed in the nucleator nozzle ring 26. As indicated above, the water exiting the snow gun 20 from the primary nozzle also font's a conical shaped body extending away from the snowgun 20. At some distance from the snowgun 20, the air-water mixture exiting the nucleator nozzles 138 and the water exiting the primary nozzle mix. Nuclei formed within the air-water mixture interact with the water from the primary nozzle 36 to create snow under the right atmospheric conditions.
The present snowgun can provide an overall air to water (A/W) ratio (cfm/gpm) of about 2.0 at marginal (26-27 degrees F.) wet bulb temperatures . . . see evaporative cooling, and a minimum level of about 0.9 when colder temperatures allow.
Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and the scope of the invention.
This application claims priority to U.S. Patent Appln. No. 61/804,454 filed Mar. 22, 2013, which application is hereby incorporated by reference in its entirety.
Number | Name | Date | Kind |
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3908903 | Burns, Jr. | Sep 1975 | A |
4353504 | Girardin et al. | Oct 1982 | A |
5135167 | Ringer | Aug 1992 | A |
5909844 | Nilsson | Jun 1999 | A |
6129290 | Nikkanen | Oct 2000 | A |
7114662 | Nikkanen | Oct 2006 | B1 |
Number | Date | Country | |
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20140284396 A1 | Sep 2014 | US |
Number | Date | Country | |
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61804454 | Mar 2013 | US |