Abstract:
A venturi nozzle producing a stream of aerated water containing air-entrained bubbles. The stream of aerated water containing air-entrained bubbles may be directed onto a fire to extinguish the fire. Water entering the venturi nozzle may be mixed with a fluid substance, such as a foam-producing substance, gas, or powdered substance suspended in air, and the mixture may be ejected from the nozzle. Embodiments of the venturi nozzle including a fire-fighting nozzle, a sprinkler head, and an array of sprinklers are described.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 60/777,611 filed on Feb. 28, 2006, the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to vacuum-induced mixing with a venturi nozzle. More particularly, systems and methods using a venturi nozzle to mix water with air and other substances are described. 
       SUMMARY 
       [0003]    In a first aspect, the present invention venturi nozzle may include a channel with a section of narrower width than the surrounding sections, an air inlet through which air can enter the channel, and an internal baffle in the channel around which water flowing through the channel can pass such that water entering the venturi nozzle is mixed with air and the mixture is ejected from the venturi nozzle producing a stream of aerated water containing air-entrained bubbles. The stream of aerated water containing air-entrained bubbles may be directed onto a fire to extinguish the fire. 
         [0004]    In a second aspect, the present invention venturi nozzle may include a channel with a section of narrower width than the surrounding sections, an air inlet through which a fluid substance can enter the channel, and an internal baffle in the channel around which water flowing through the channel can pass such that water entering the venturi nozzle is mixed with the fluid substance and such mixture is ejected from the venturi nozzle. The fluid substance may be a foam substance containing suspended encapsulated air. 
         [0005]    In a third aspect, the present invention firefighting nozzle may include a channel having a section of narrower width than the surrounding sections, an air inlet through which air can enter the channel, and an internal baffle in the channel around which water flowing through the channel can pass such that water entering the venturi nozzle is mixed with air and the mixture is ejected from the venturi nozzle producing a stream of aerated water containing air-entrained bubbles which may be directed onto a fire to extinguish the fire. 
         [0006]    In a fourth aspect, the present invention fire sprinkler may include a venturi nozzle having a channel including a section of narrower width than the surrounding sections, an air inlet through which air can enter the channel, and an internal baffle in the channel around which water flowing through the channel can pass such that water entering the venturi nozzle is mixed with air producing aerated water containing air-entrained bubbles which is ejected from the venturi nozzle. A sprinkler head may be coupled to the venturi nozzle at the point where the mixture is ejected from the venturi nozzle, the sprinkler head being adapted to spread the mixture over a relatively wider area such that the mixture of aerated water containing air-entrained bubbles may be sprayed onto a fire to extinguish the fire. The fire sprinkler may further include a source of foam in fluid communication with the air inlet such that the foam may be mixed with the water to produce aerated water containing air-entrained bubbles and foam and the mixture of aerated water containing air-entrained bubbles and foam may be sprayed onto a fire to extinguish the fire. 
         [0007]    In a fifth aspect, the present invention array of fire sprinklers may include a plurality of fire sprinklers. Each fire sprinkler may include a venturi nozzle having a channel with a section of narrower width than the surrounding sections, an air inlet through which air can enter the channel, and an internal baffle in the channel around which water flowing through the channel can pass such that water entering the venturi nozzle is mixed with air to produce aerated water containing air-entrained bubbles and such that the mixture is ejected from the venturi nozzle; and a sprinkler head coupled to the venturi nozzle at the point where the mixture is ejected from the venturi nozzle, the sprinkler head being adapted to spread the mixture over a relatively wider area and a source of foam in fluid communication with each of the plurality of air inlets such that each of the venturi nozzles is in fluid communication with a common supply of water such that the foam is mixed with the water in each of the venturi nozzles to produce aerated water containing air-entrained bubbles and foam which may be sprayed onto a fire to extinguish the fire. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0008]      FIG. 1  shows the venturi nozzle, according to an exemplary embodiment of the present invention. 
           [0009]      FIG. 2  shows the venturi nozzle in a firefighting application, according to an exemplary embodiment of the present invention. 
           [0010]      FIG. 3  shows the venturi nozzle with a sprayer attachment, according to an exemplary embodiment of the present invention. 
           [0011]      FIG. 4  shows the venturi nozzle in a firefighting sprinkler application, according to an exemplary embodiment of the present invention. 
           [0012]      FIG. 5  shows a plurality of venturi nozzles in a firefighting sprinkler application, according to an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0013]      FIG. 1  shows a side cutaway view of a venturi nozzle  10 , according to an exemplary embodiment of the present invention. Water is supplied to the venturi nozzle  10  through inlet  12 , and the water flow velocity is increased as the water passes through the channel  16 . The narrowed stream of water emerging from the channel  16  strikes the butt end  18  of the baffle  20 , which is held in place by radial stays  24 . Upon striking the butt end  18 , the water is dispersed into the annular region surrounding the baffle  20 . The dispersion of the water creates a partial vacuum in the region between the channel  16  and the baffle  20 , and air is drawn in through port  14 . The water and air pass around the baffle  20  through the annular region, and over the pointed end  22  of the baffle  20 . The turbulence resulting from the pass around the baffle  20  mixes the air with the water. The aerated water then exits the venturi nozzle  10  through opening  26 . In an exemplary embodiment, the overall diameter of the nozzle body is 40 mm (1.6 inches), the pointed end  22  of the baffle  20  is tapered with an angle of 30 degrees, the baffle  20  has an overall length of 76 mm (3 inches) with the tapered portion being 25 mm (1 inch) long, the butt end  18  of the baffle  20  is located 18 mm (0.7 inches) away from the end of the channel  16  from which water emerges, and the channel  16  and baffle  20  each have a diameter of 19 mm (0.75 inches). In an alternative embodiment, the overall diameter of the nozzle body is 51 mm (2.0 inches), the channel  16  and baffle  20  each have a diameter of 25 mm (1.0 inch), and the other measurements have the same values as in the first embodiment described above. In additional embodiments, other values for these parameters could be used to achieve the desired performance and mixing characteristics, as will be appreciated by persons skilled in the art. 
         [0014]      FIG. 2  shows the venturi nozzle  10  being used in a firefighting application. Water is supplied by a fire hose  50  connected to the venturi nozzle  10 . The water is mixed with air by the venturi nozzle as described above, and a stream of aerated water  54  exits the venturi nozzle. When the stream of aerated water  54  is directed onto a fire  56 , the water rapidly flashes to steam. The water/air mixture in the stream  54  contains tiny air-entrained bubbles in a balance, which allow heat to be transferred to the water much more rapidly than would be possible with non-aerated water. As the water flashes to steam, a cloud  58  of steam and condensation envelops the fire  56 , rapidly extinguishing the fire. Additionally, the vaporization of the aerated water results in a rapid loss of heat from the fire, which further speeds up the fire extinguishing process. Use of the venturi nozzle  10  as a firefighting nozzle has the further advantage of producing less recoil force when operated due to the reduced mass flow rate of water needed. This, in turn, allows the hose and nozzle to be operated with fewer firefighters or a less massive support apparatus to hold it in place. 
         [0015]      FIG. 3  shows the venturi nozzle  10  equipped with a sprayer  30  to finely disperse the water/air mixture that exits the venturi nozzle, according to an exemplary embodiment of the present invention. The sprayer  30  includes a tapered disc having a maximum diameter that is approximately equal to the diameter of the exit orifice  26  of the nozzle body  28 . The disc of the sprayer  30  has a bolt  32  with a threaded end  34 . This threaded end  34  can be threaded into a hub  36  that is held in place along the longitudinal centerline of the nozzle body  28  by radial stays  38 . As the water/air mixture exits the venturi nozzle  10  through the exit orifice  26 , it is deflected by the sprayer  30 , producing a relatively fine mist. This sprayer attachment can be used with the venturi nozzle in a variety of applications, some of which are described below, where it is desired to obtain a fine spray or mist of water-air mixture exiting the venturi nozzle. 
         [0016]      FIG. 4  shows the venturi nozzle  10  fitted with a sprinkler head  40 . The sprinkler head  40  can be fitted to the venturi nozzle  10  in the same manner as the sprayer described above with reference to  FIG. 3 . This embodiment allows the venturi nozzle, with its aerating function, to be employed for emergency fire sprinkler units. A reservoir  42  may be connected in fluid communication with the venturi nozzle&#39;s air intake port  14  to provide a source of foam or other substance to aid in fire suppression. The foam or other substance contained in the reservoir  42  will be drawn into the venturi nozzle by the vacuum effect described above, where it will be mixed with water and expelled over the sprinkler head  40 , which spreads the mixture over a wider area. Because foam contains encapsulated air suspended in the substance and therefore has a relatively low density, it is an ideal form for a substance to be mixed using the vacuum-induced mixing of the venturi nozzle. The supply of water can be activated in response to detection of a fire or other hazard in a manner known to persons skilled in the art. 
         [0017]      FIG. 5  shows an embodiment in which a plurality of venturi nozzles  10 , each fitted with a sprinkler head  40 , have been connected to common supply lines. Water is supplied to each venturi nozzle  10  by a common water supply line  44 . The air intake ports  14  of the venturi nozzles  10  have been connected to a common supply line  46 . The supply line  46  can be connected to a reservoir or source of foam or other substance to be mixed with the water to aid in fire suppression, as discussed above. 
         [0018]    In another embodiment, the venturi nozzle described herein can be used in a variety of applications where the mixing of fluid substances is desired. For example, many industrial and manufacturing processes involve the mixing or application of foam-based products, such as insulation. In addition to foam-based products, the venturi nozzle can be used to mix water or another liquid with any gas, or with another liquid, or with a finely-ground or powdered substance suspended in air. 
         [0019]    In another embodiment, the venturi nozzle described herein can be used for aeration of a pond, aquarium, or other reservoir where increased concentration of oxygen is desired. The mixing of air with water by the venturi nozzle produces an air-rich stream, as discussed above. When this air-rich stream is directed to a body of water, oxygen in the air-rich stream dissolves in the water, thus increasing the concentration of dissolved oxygen in the water. 
         [0020]    Following from the above description and invention summaries, it should be apparent to persons of ordinary skill in the art that, while the methods and apparatuses herein described constitute exemplary embodiments of the present invention, it is to be understood that the inventions contained herein are not limited to the above precise embodiments and that changes may be made without departing from the scope of the invention as defined by the following proposed points of novelty. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the invention disclosed herein in order to fall within the scope of the invention, since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein.