Patent Publication Number: US-10322425-B2

Title: Water atomisation device

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/714,283, filed Dec. 13, 2012, which claims priority to Australian Application No. 2012238201, filed Oct. 4, 2012, the disclosures of which are incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a water atomisation device adapted for water evaporation and/or dust control. 
     The invention has been primarily developed for use in the draining of bodies of water on mine and construction sites and will be described hereinafter with reference to this application. The invention is also suitable for use in wetting a very large land surface area for dust control in arid environments. 
     BACKGROUND OF THE INVENTION 
     Devices are known which are able to atomise water and eject into the atmosphere as a fine mist. These devices are used in snow making and low volume misting for evaporative cooling and/or localised dust control. The disadvantage of such known devices is they are not suitable for large scale waste water evaporation and/or dust control applications. 
     OBJECT OF THE INVENTION 
     It is the object of the present invention to substantially overcome or at least ameliorate the above disadvantage. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, in a first aspect, the present invention provides a water atomisation device for water evaporation and/or dust control, the device including: 
     a generally longitudinal hollow housing extending between an inlet end and an outlet end, the inlet end defining a first air inlet to an interior of the housing; 
     a fan within the housing between the inlet end and the outlet end; 
     a motor for driving the fan; and 
     a hollow manifold shaped to generally correspond to that of the outlet end and having a plurality of water injector nozzles directed substantially inwardly and away from the outlet end. 
     wherein a distal edge of the outlet end is longitudinally spaced apart from a proximal edge of the manifold to define a second air entrainment inlet to an interior of the manifold. 
     The distal edge of the outlet end is longitudinally spaced apart from the proximal edge of the manifold by about 35 mm. 
     The housing is preferably generally cylindrical. The housing inlet end preferably includes a venturi part, converging towards the outlet end. The housing outlet end preferably includes a tapered part, converging away from the inlet end. The device preferably includes an air flow straightener, within the housing, between the fan and the tapered part. The housing preferably includes a cylindrical part between the venturi part and the air flow straightener. The fan and the majority of the motor are preferably mounted within the cylindrical part. 
     The manifold is preferably annular, with a substantially round cross section. 
     The motor is preferably about 75 kilowatts. The motor and fan are preferably adapted to eject air from the housing at about 45 metres/second. The water injectors are preferably adapted to inject water at about 24 litres/second. The motor, fan and water injectors are preferably adapted to discharge at least 2000 litres of air for every 1 litre of atomised water. 
     The nozzles each preferably have a water opening therein of about 3.2 mm in diameter. 
     The housing is preferably about 1220 mm in diameter. 
     In a second aspect, the present invention provides a water atomisation device adapted capable of discharging at least 2000 litres of air for every 1 litre of atomised water, the device including: 
     a generally longitudinally hollow housing about 1220 mm in diameter and extending between an inlet end and an outlet end, the inlet end defining a first air inlet to an interior of the housing; 
     a fan within the housing between the inlet end and the outlet end; 
     a motor of about 75 kilowatts for driving the fan to eject air from the housing at about 45 metres/second; and 
     a hollow manifold shaped to generally correspond to that of the outlet end and having a plurality of water injector nozzles directed substantially inwardly and away from the outlet end to inject water at about 24 litres/second, 
     wherein a distal edge of the outlet end is longitudinally spaced apart from a proximal edge of the manifold by about 35 mm to create a second air entrainment inlet to an interior of the manifold. 
     In a third aspect, the present invention provides a method of operating a water atomisation device for water evaporation and/or dust control, the device including: a generally longitudinally hollow housing extending between an inlet end and an outlet end, the inlet end defining a first air inlet to an interior the housing; a fan within the housing between the inlet end and the outlet end; a motor for driving the fan; and a hollow manifold shaped to generally correspond to that of the outlet end and having a plurality of water injector nozzles directed substantially inwardly and away from the outlet end, a distal edge of the outlet end is longitudinally spaced apart from a proximal edge of the manifold to define a second air entrainment inlet to an interior of the manifold, 
     the method including the steps of:
         1. energising the motor to rotate the fan and draw air into the housing inlet end and eject it from the housing outlet end;   2. pumping water through the injectors;   3. atomising the water leaving the injectors by impacting it with the air ejected by the fan; and   4. entraining additional air through the second air entrainment inlet into the air ejected by the fan.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred embodiment of the invention will now be described, by way of an example only, with reference to the accompanying drawings in which: 
         FIG. 1  is a side view of an embodiment of a water atomisation device; 
         FIG. 2  is front view of the device shown in  FIG. 1 ; 
         FIG. 3  is a front perspective view of the device shown in  FIG. 1 ; and 
         FIG. 4  is a cross sectional side view of the device shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 to 4  show an embodiment of a water atomisation device  10  used to drain bodies of water on mine or construction sites and also to wet a large land surface area for dust control in arid environments. 
     The device  10  includes a steel, generally longitudinal, cylindrical hollow housing  12 . The housing  12  has a diameter of about 1200 mm and is about 2400 mm long. The housing  12  extends between an inlet end  12   a  and an outlet end  12   b . The inlet end  12   a  defines a first air inlet to an interior of the housing  12 . 
     The housing  12  is mounted to a skid plate assembly  14  by a pair of brackets  16 . The brackets  16  allow the angle of the longitudinal axis x-x of the housing  12  to be adjusted in order to adjust the trajectory of the material ejected from the device  10 . The skid plate assembly  14  allows the device  10  to be moved using a forklift, as is well understood by persons skilled in the art. 
     As best shown in  FIG. 4 , the device  10  includes a fan  18  within the housing  12 , between the inlet end  12   a  and the outlet end  12   b . A 75 kilowatt electric motor  20  drives the fan  18 . 
     A hollow annular manifold  22  is mounted to the housing  12  near the outlet end  12   b.  The manifold  22  is sized and shaped to generally correspond to the size and shape of the outlet end  12   b  and has a prurality of water injector nozzles  24  which are directed substantially inwardly and away from the outlet end  12   b . The nozzles  24  have an internal diameter of about 3.2 mm. This allows relatively dirty water to be pumped through the nozzles without clogging. 
     A distal edge of the outlet end  12   b  of the housing  12  is longitudinally spaced apart from a proximal edge of the manifold  22  in order to create an annular gap  25  therebetween of approximately 35 mm in the direction of the longitudinal axis x-x of the housing  12 . The manifold  22  has an inlet fitting  22   a  suitable for connection to a water hose. 
     As previously mentioned, the housing  12  is generally cylindrical. The housing inlet end  12   a  includes a venturi part  26 , which converges towards the outlet end  12   b . The housing outlet end  12   b  includes a tapered part  28 , which converges away from the inlet in  12   b . An air flow straightener  30  is positioned within the housing  12 , between the fan  18  and the tapered part  28 . The housing  12  also includes a cylindrical part  32  between the venturi part  26  and the air flow straightener  30 . The fan  18  and the majority of the motor  20  are mounted within the cylindrical part  32 . 
     The operation of the device  10  will now be described. To operate the device  10 , the motor  20  is energised to rotate the fan to cause air to be drawn into the inlet  12   a  and ejected from the outlet  12   b  at about 45 m/sec. Simultaneously, an external pump (not shown) is connected to the inlet fitting  22   a  and used to pump water through the nozzles  24  at about 24 litres/second. The water leaving the injectors  24  is atomised when it comes in the contact with the high velocity air (45 m/sec) being ejected from the housing  12  as a plume of air and atomised water. The motor  20  and the fan  18  discharge at least about 2000 litres of air for every 1 litre of atomised water pumped through the water nozzles  24 . 
     As the air passes through the opening in the manifold  22 , and past the nozzles  24 , it causes additional air to be entrained through the gap  25  between the housing  12  and the manifold  22 . The entraining of the additional air through the gap  25  induces a larger volume airstream from the surrounding environment and thereby carries the plume of air and atomised water higher into the atmosphere then would be case without such additional entrained air. This increases the amount of time the atomised water droplets spend in the air and therefore increases the evaporation rate thereof. This also enable the device  10  to be operated with the relatively high water injection rates (about 24 litres/sec) whilst still maintaining a suitable water droplet size. Accordingly, this enables the device  10  to be particularly suitable for relatively fast draining and evaporation of relatively large bodies of water. The combination of the mechanical fracturing of the water particles, the high airstream velocity at the outlet end  12   b  of the housing  12 , the relatively large volume of air actually discharged and the entrained surrounding air enables a significant performance increase in evaporation and also in the control of dust particles when the device is used for dust control. 
     Although, the invention has been described with reference to a preferred embodiment, it will be appreciated by persons skilled in the art that the invention can be embodied in many other forms. For example, acoustic shielding can be added to the housing to reduce the noise generated by the device.