WO2009043092A1

WO2009043092A1 - Snow making equipment

Info

Publication number: WO2009043092A1
Application number: PCT/AU2008/001452
Authority: WO
Inventors: Mitchell Joe Dodson
Original assignee: Ballistic Australia Pty Ltd
Priority date: 2007-10-04
Filing date: 2008-10-01
Publication date: 2009-04-09

Abstract

A snow making gun comprising a manifold arranged to be coupled to a source of compressed air and a source of water, the manifold having a water conduit arranged to feed water to an adjustable flat jet nozzle having an outlet aperture, the manifold also including an air conduit, whereby air and water are arranged to be fed to a nucleator having an exit aperture positioned above the outlet orifice of the flat jet nozzle, an adjustable valve controlling flow of water to the nucleator, whereby in use, the nucleator projects ice particles above a flat plume of water droplets from the flat jet nozzle.

Description

Title: Snow Making Equipment

Introduction

This invention relates to snow making equipment and, in particular, a manifold for such equipment and an improved nucleator for use with this equipment. This invention also relates to improvements in adjustable flat jet nozzles .

Background of the Invention In my earlier patent application, WO2004/087329, I disclosed the use of an adjustable flat jet nozzle in snow making equipment. This application relates to further improvements of this equipment as well as the design of an improved nucleator which can be used in combination with an adjustable flat jet nozzle.

The nucleators that are conventionally used in the snow making industry comprise a fixed orifice water nozzle fed from an air and water mixing chamber. The mixing chamber usually exits via a fixed orifice or sometimes to an interchangeably sized orifice. The efficiency and energy consumption of a snow making gun is based on compressed air usage. Thus the orifice diameters of nucleators are generally very small. This makes them very susceptible to blockage from debris. In order to combat blockage, various forms of filters are generally used. In the event of nozzle blockage, the nozzle must be removed and cleaned.

It is consideration of these issues that has brought about the present invention.

Summary of the Invention

According to a first aspect of the present invention, there is provided a snow making gun comprising a manifold arranged to be coupled to a source of compressed air and a source of water, the manifold having a water conduit arranged to feed water to an adjustable flat jet nozzle having an outlet orifice, the manifold also including an air conduit whereby air and water are arranged to be fed to a nucleator having an outlet aperture positioned above the outlet orifice of the flat jet nozzle, an adjustable valve controlling flow of water to the nucleator, whereby in use the nucleator projects ice particles above a flat plume of water droplets from the flat jet nozzle.

In accordance with a further aspect of the present invention there is provided a manifold for snow making equipment, the manifold comprising an adjustable nucleator positioned above an adjustable flat jet nozzle whereby the nucleator is arranged to be coupled to a source of compressed air and both the nucleator and flat jet nozzle are arranged to be coupled to a source of water.

Preferably the nucleator comprises a converging-diverging nozzle with inlet and exit apertures, a mixing chamber for mixing air and water to be fed to the inlet of the nozzle and an adjustable valve to control flow of water to the mixing chamber. Preferably the converging-diverging nozzle is interchangeable, each nozzle being of differing dimensions .

In accordance with a further aspect of the present invention there is provided a nucleator for snow making comprising a mixing chamber adapted to be fed by a source of water and compressed air, a converging-diverging nozzle having an inlet and an outlet, the mixing chamber being arranged to feed an air/water mixture to the inlet of the nozzle.

According to a still further aspect of the invention there is provided a nozzle for producing a flat spray pattern, the nozzle comprising a fluid passageway terminating in a cross member having an end wall having an outlet aperture, the cross member defining at least two deflectors that converge towards the aperture to deflect the fluid towards the aperture; the cross member supporting axially displaceable pins adapted to move across the aperture to decrease or increase the cross section of the aperture, wherein the aperture is an elongate slit with walls diverging slightly outwardly from the centre of the aperture .

Preferably the ends of the pins are chamfered.

In one embodiment electrically driven linear actuators control the displacement of the pins .

Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a plan view of a manifold for use in snow making equipment illustrating the superimposition of a plane of ice crystals with a plume of water;

Figure 2 is a side elevational view of the manifold again illustrating the superimposition;

Figure 3 is a plan view of the manifold illustrating a nucleator control valve;

Figure 4 is a cut-away view of the manifold from the side illustrating the nucleator;

Figure 5 is a perspective view of a convergent-divergent nozzle forming part of the nucleator;

Figure 6 is an exploded view of a water control valve; Figure 7 is a front perspective view of the manifold illustrating the association of the nucleator and a flat jet nozzle;

Figure 8 is an exploded view of a flat jet nozzle;

Figure 9 is a front elevational view of the assembled flat jet nozzle;

Figure 10 is a sectional view taken from the rear of the flat jet nozzle; and

Figure 11 is a side elevational view of a pin used in the flat jet nozzle.

Description of the Preferred Embodiment

As shown in the accompanying drawings, snow making equipment includes a manifold 10, the manifold includes two adjustable flat jet nozzles 20 and 21, each having a nucleator 50 and 51 positioned above the nozzles so that, in use, the nucleators form ice crystals that are projected in plumes above the flat plumes of water particles that are projected by the adjustable flat jet nozzles .

As shown in Figures 1 and 2, the manifold 10 comprises two machined metal blocks 11 and 12 that are joined end to end to form an obtuse angle so that the projecting plumes diverge from one another as shown in Figure 1. As shown in Figure 2, the nucleator 51 is positioned vertically above the adjustable flat jet nozzle 21. Each block 11 and 12 has a common water port 13 and a separate common air port 14. Each end of each block 11, 12 is adapted to be connected to a source of water and air. Each block 11 and 12 also includes a machined transverse passage 15 that extends from the rear to the front of the block and supports the nucleator 50, 51 which in turn comprises an adjustable water valve 60 and a convergent-divergent nozzle 70. Each adjustable flat jet nozzle 20, 21 is housed in a rectangular block 22, details of which are described later. As shown in Figures 2 and 3, the common water port 13 feeds both the nucleator 50, 51 and the flat jet nozzle 20, 21 and the air port 14 feeds the nucleator 50, 51. As shown in Figure 2, the nucleator terminates in an exit aperture 55 that is spaced vertically above the exit aperture 25 of the adjustable flat jet nozzle 21. Furthermore, as shown in Figure 2, the exit aperture 25 of the flat jet nozzle 21 is positioned forwardly of the exit aperture 55 of the nucleator 51.

As shown in Figure 4, the nucleator 51 is housed in the passageway 15 of the manifold and includes a valve body 52 that is fixed into the passageway 15 and sealed therein by a pair of spaced 0-rings 53, 54, the valve body 52 has a central throughway 56 which supports and elongate needle valve 57 that has one end with a tapered tip 58 and the other end connected to a knurled adjusting knob 59 that is mounted externally of the manifold 10. The tip 58 of the needle valve 57 is axially displaceable relative to an aperture in the valve body 52 to provide an adjustable nozzle. This defines a mixing chamber in which air coming from the air port 14 in an annular manner enters the air chamber to meet with water flowing down the centre of the valve and controlled by the needle jet 57. The water enters the valve by a transverse port 61 that is coupled to the water port 13. The mixing chamber communicates with the convergent-divergent mixing nozzle 70 which is mounted in the block 12 to be replaceable so that mixing nozzles of different dimensions can be positioned in the nucleator. The mixing nozzle terminates in the exit orifice 55.

Details of the mixing nozzle 70 are shown in Figure 5 where the nozzle is housed in a cylindrical body 71 that can be located in the throughway 15 and removed by accessing small spaced holes. The inlet tapers 74 down through a conical converging component to a narrow nucleator throat 75 with a cylindrical wall to then conically taper outwardly to the exit orifice. The throat 75 to exit orifice 55 ratio is preferably between 1.5 to 1.85:1. This ratio is dependent on the operating pressure of the compressed air. The air consumption is dictated by the nucleator throat diameter.

Details of the valve body 52 and needle valve 57 are shown in greater detail with reference to Figure 6. This illustrates that the needle valve 57 has a threaded portion 63 that is able to screw into a similarly threaded recess 64 in the valve body 52 so that rotation of the knurled knob 59 causes the valve tip 58 to move axially towards and away from the valve seat 65 defined by the end of the valve body 52. The needle and seat arrangement controls the amount of water that flows into the mixing nozzle. This design allows for a larger water exit orifice which can be fully opened in the event of a blockage to permit the debris to pass through with subsequent return to a smaller opening size for normal operation.

The nucleator 50, 51 does not require removal from the manifold 10 to facilitate the cleaning of debris. The control valve adjusts the volume of water entering the mixing nozzle 70. Mixing nozzles 70 of differing size may be interchanged into the manifold and the interchangeable mixing nozzles allow for a variance in the air consumption and, combined with the adjustable water control valve, maintain the correct air to water ratio, thus in effect forming a variable nucleator.

The convergent-divergent nozzle 70 of the nucleator 50, 51 is designed to create a Laval effect accelerating the air and water mixture to supersonic speeds. The Laval effect lowers the gas temperature to temperatures between -4O⁰C to -90⁰C. This transforms the air and water mixture into ice crystals which are ejected at high speed into the variable flat jet water plume. The ice crystals, which act as high temperature nucleators, seed the water droplets allowing the water droplets to give off their latent heat and convert to snow.

In my earlier patent application WO2004/087329 the disclosure of which is incorporated herein by reference, I describe an adjustable flat jet nozzle in which a pair of axially aligned pins can be moved to and from each other across the mouth of an aperture to define a flat jet, characteristics of which can be adjusted by movement of the pins. In WO2004/087323 the adjustable flat jet nozzle is in the form of a T piece with the water flowing down the leg of the T and the pins being axially displaceable across the arms of the T. The arms or cross member of the 'T' define at least two deflectors that converge towards the aperture to deflect the water towards the aperture.

The outlet aperture is a circular hole in the T piece and the pins have planar faces substantially perpendicular to the axes of the pins .

In the adjustable flat jet nozzle 100 shown in Figures 8 to 11 the outlet orifice has been replaced by an elongate slit 101 that diverges outwardly at the ends 102 and 103. This orifice 101 changes the water droplet size and they start small at the centre but gradually get larger towards the ends 102, 103 of the orifice. The pins 104 and 105 are axially displaceable across the orifice 101 but instead of having the planar ends, the pins have chamfered ends 110 as shown in figure 11 in which a planar bevelled edge 111, 112 is positioned on each side of the tip 113 of the pin 104 to meet at a point. The angle of the bevel being between 30°-45° off the transverse plane.

The divergence of the elongate orifice 101 is dependent on the width and length of the slit. As shown in Figure 10 the pins are driven by a threaded drive from drive shafts 120, 121 extending outwardly from either end of the nozzle housing. The design of the threaded coupling is such that the pins 104, 105 can move from an open position at ends of the elongate orifice 101 to a closed position at the centre of the orifice.

It is understood that the drive mechanism which is the same as the mechanism described in WO2004/087329 can be replaced by small linear actuators that would be attached to each pin 104, 105. The linear actuators are driven by a low voltage DC supply and displacement can be controlled to high tolerances to drive the pins 104, 105 back and forth across the orifice 101.

The radii of the ends 102, 103 of the orifices 101 are the same. The minimum radius is dependent on the initial width of the orifice. As the chamfered pins 104, 105 pull back they progressively open the orifice 101 so the slit grows in length and width. The width of the orifice 101 determines water particle size. This design results in smaller water droplets being produced when the pins 104, 105 are close together, with the droplets growing in size as the pins move further apart. Smaller water droplets are desirable in marginal snow making conditions with progressively larger droplets being desirable as the air temperature continues to fall. The spray angle of the variable flat jet nozzle is determined by the chamfer of the pins. Although the chamfer is described as being on both sides it is understood that a single chamfer on one side can be utilized. The chamfer also does not require a flat face with a variety of curves being envisaged. It is considered that the combination of the orifice opening width and the pin chamfer determines the spray angle .

The flat jet described above is specifically designed for use in association with snowmaking equipment. It is, known, understood that this nozzle is applicable to many fields totally unrelated to snowmaking. The nozzle has applicability in any industrial spraying application where there is a need for a variable flat jet nozzle, especially fire fighting.

The manifold described above can be used in a variety of snow making equipment such as on a sled which can be towed behind a snow mobile, onto an extruded mast or varying heights. It can be positioned on a rotating head or a fixed head again on a mast. It can be placed on top of a fan gun, or attached directly to a snow making water hydrant.

The combination of an adjustable flat jet nozzle and a nucleator of the kinds discussed above provide snow making equipment that operates at much lower energy consumption than conventional snow making equipment.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1 A snow making gun comprising a manifold arranged to be coupled to a source of compressed air and a source of water, the manifold having a water conduit arranged to feed water to an adjustable flat jet nozzle having an outlet aperture, the manifold also including an air conduit, whereby air and water are arranged to be fed to a nucleator having an exit aperture positioned above the outlet orifice of the flat jet nozzle, an adjustable valve controlling flow of water to the nucleator, whereby in use, the nucleator projects ice particles above a flat plume of water droplets from the flat jet nozzle.

2 The snow making gun according to claim 1 wherein the nucleator includes a converging-diverging nozzle with inlet and exit apertures and a mixing chamber for mixing air and water to be fed to the inlet of the converging- diverging nozzle.

3 The snow making gun according to either claim 1 or 2 wherein the converging-diverging nozzle is interchangeable, each nozzle being of differing dimensions .

4 The snow making gun according to any one of the preceding claims wherein the outlet aperture is an elongate slit with walls diverging slightly outwardly from the centre of the aperture .

5 The snow making gun according to any one of the preceding claims wherein the adjustable flat jet nozzle comprises a fluid passageway terminating in a cross member having the outlet aperture, the cross member defining at least two deflectors that converge towards the aperture to deflect the fluid towards the aperture; the cross member supporting axially displaceable pins adapted to move across the aperture to decrease or increase the cross- section of the aperture.

6 The snow making gun according to claim 5 wherein the ends of the pins are chamfered.

7 The snow making gun according to either claim 5 or 6 wherein electrically driven linear actuators control displacement of the pins.

8 A nozzle for producing a flat spray pattern, the nozzle comprising a fluid passageway terminating in a cross member having the outlet aperture, the cross member defining at least two deflectors that converge towards the aperture to deflect the fluid towards the aperture; the cross member supporting axially displaceable pins adapted to move across the aperture to decrease or increase the cross-section of the aperture, wherein the outlet aperture is an elongate slit with walls diverging slightly outwardly from the centre of the aperture.

9 The nozzle according to claim 8 wherein the ends of the pins are chamfered.

10 The nozzle according to either claim 8 or 9 wherein electrically driven linear actuators control displacement of the pins . 11 A nucleator for snow making comprising a mixing chamber adapted to be fed by a source of water and compressed air, a converging-diverging nozzle having an inlet and an outlet, the mixing chamber being arranged to feed an air/water mixture to the inlet of the nozzle.

12 The nucleator according to claim 11 wherein an adjustable valve controls flow of water to the mixing chamber .