Abstract:
A misting head system ( 24 ) configured to render a fluid ( 32 ) into a mist ( 36 ) is provided. The system ( 24 ) includes a misting head body ( 26 ) and a poppet ( 20 ). The misting head body ( 26 ) has a cylindrical chamber ( 28 ), an inlet ( 30 ) configured to pass the fluid ( 32 ) into the chamber ( 28 ), and an orifice ( 34 ) configured to pass the fluid ( 32 ) out of the chamber ( 28 ) and to render the fluid ( 32 ) into the mist ( 36 ). The poppet ( 20 ) has a cylindrical core ( 38 ) configured to force the fluid ( 32 ) to pass through a space ( 44 ) between the core ( 38 ) and an inner wall ( 46 ) of the chamber ( 28 ), a fracture band ( 54 ) coupled to the core ( 38 ), configured to center the core ( 38 ) within the chamber ( 28 ), and having a plurality of flutes ( 60 ) configured to fracture the fluid ( 32 ) as the fluid ( 32 ) passes through the space ( 44 ), and an orifice end ( 40 ) of the core possessing a plurality of symmetrically spaced slits ( 48 ) configured to further fracture the fluid ( 32 ).

Description:
RELATED INVENTION 
     The present invention is a continuation in part (CIP) of “Misting Head poppet,” U.S. patent application Ser. No. 29/095,590, filed Oct. 27, 1998, and now U.S. Pat. No. 0,412,557, which is incorporated by reference herein. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to the field of misting systems. More specifically, the present invention relates to misting head poppets. 
     BACKGROUND OF THE INVENTION 
     A misting system converts a fluid, typically water, into a mist or fog. One of the primary uses of such a system is to cool the proximate area. Such cooling takes place by evaporation of the mist or fog. The efficiency of evaporation, hence the efficiency of cooling, is a function of droplet size. The smaller the droplet, the more rapid its evaporation and the greater the cooling efficiency. A type of mist more precisely considered to be a fog is preferable to a mist having larger droplets. 
     A misting system has one or more misting heads, which perform the actual conversion of the fluid into a mist or fog. In order to accomplish this, the misting head fractures the water, i.e., disrupts molecular cohesion. The fluid enters the misting head under pressure. A fluid moving under pressure pulsates. This pulsation is due in part to air entrained within the fluid, and in part to turbulence created by friction and other factors. 
     The pulsating fluid exits the misting head through an orifice. This orifice serves to fracture the fluid into a fine spray. Usually, this fracturing is insufficient to produce the desired mist or fog, and further fracturing is desirable. 
     This further fracturing is typically provided by the addition of a poppet to the misting head. The misting head is formed with a cylindrical chamber within which the poppet resides. The pulsation of the fluid causes the poppet to vibrate within the chamber and fracture the fluid. This fractured fluid then exits the misting head through the orifice and undergoes further fracturing. This compound fracturing action improves the quality of atomization compared to systems that do not employ compound fracturing. 
     A problem occurs in that the poppet may occasionally seat against the orifice in such a manner that the flow is cut off. Should this occur, the fluid pressure may serve to hold the poppet in this position. In conventional misting heads, this problem is solved by cutting one or more small blind slits in the orifice end of the poppet. These slits serve to prevent a perfect seal from forming between the end of the poppet and the orifice. Without such a seal, the fluid vibration serves to prevent the poppet from remaining in this position. Also, these slits cause the poppet to spin. This spin serves to increase the vibration of the poppet. This increased vibration increases the fracturing of the fluid. Additionally, the edges of the slits themselves create an additional turbulence of the fluid. This additional turbulence again increases the fracturing action. 
     The poppet must be smaller in diameter than the chamber in which it resides. This allows the poppet to spin and vibrate within the chamber and allows fluid to pass by the poppet within the chamber. A problem exists, however, in that the poppet may undergo a certain amount of lateral movement within the chamber. This lateral movement varies the space between the poppet and the chamber wall in a totally random manner. This in turn produces random variations in the pressure present at the orifice, hence the degree of fracture produced by the orifice. This may result in spitting, dribbling, or other undesirable output from the misting head. 
     Additionally, the poppet may become skewed and wedge within the chamber. This is accompanied by a significant decrease in the amount of fracture and an undesirable degradation of the output from the misting head. 
     What is desirable, therefore, is a way of keeping a poppet centered within a misting head chamber and controlling lateral poppet movement. This would in turn maintain a controlled pressure at the orifice, a controlled fracture, and a controlled misting head output. 
     Even with the fracture slits, a problem also remains in that the pressure must be relatively high to produce a smaller droplet fog rather than a larger droplet type of mist. This high pressure is reflected in more robust piping and other components, including the misting heads themselves. 
     What is desirable, therefore, is a way of increasing the amount of fracture, thus producing a given fog output at a lower pressure. This in turn would allow a decrease in component robustness for a given amount of mist, with a corresponding decrease in system cost and complexity. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an advantage of the present invention that an improved misting head poppet is provided. 
     It is another advantage of the present invention that a misting head poppet is provided that has a cylindrical adaptation configured to inhibit the lateral movement of the poppet and prevent the poppet from becoming cocked within the misting head chamber. 
     It is another advantage of the present invention that a misting head poppet is provided that has a cylindrical adaptation configured to center the poppet within the misting-head chamber, thus stabilizing orifice pressure for a more uniform misting action. 
     It is another advantage of the present invention that a misting head poppet is provided that has a fracture band configured to fracture the fluid, thus adding to the overall fracture of the fluid and producing a finer mist or fog for a given pressure. 
     The above and other advantages of the present invention are carried out in one form by a poppet for a misting head, wherein the misting head is configured to render a fluid into a mist, has a body, a cylindrical chamber within the body, an inlet into the chamber, and an orifice opposing the inlet. The poppet has a cylindrical core configured to reside within the chamber, wherein a first end of the core is configured to be positioned within the chamber proximate the orifice, and a second end of the core is configured to be positioned within the chamber farther from the orifice than the first end. The poppet has a fracture band coupled to the core and configured to center the core within the chamber. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the Figures, wherein like reference numbers refer to similar items throughout the Figures, and: 
     FIG. 1 shows a front perspective view of a misting head poppet in accordance with a preferred embodiment of the present invention; 
     FIG. 2 shows a front view of the misting head poppet of FIG. 1, a rear view being identical thereto, in accordance with a preferred embodiment of the present invention; 
     FIG. 3 shows a left side view of the misting head poppet of FIG. 1, a right side view being identical thereto, in accordance with a preferred embodiment of the present invention; 
     FIG. 4 shows an input end view of the misting head poppet of FIG. 1 in accordance with a preferred embodiment of the present invention; 
     FIG. 5 shows an orifice end view of the misting head poppet of FIG. 1 in accordance with a preferred embodiment of the present invention; 
     FIG. 6 shows a cutaway front view of a misting head in accordance with a preferred embodiment of the present invention; 
     FIG. 7 shows a cutaway front view of the misting head of FIG. 6 with the misting head poppet of FIG. 1 located therein in accordance with a preferred embodiment of the present invention; 
     FIG. 8 shows a front view of a portion of an edge of a fracture band with longitudinal flutes in accordance with a first preferred embodiment of the present invention; 
     FIG. 9 shows a front view of a portion of an edge of a fracture band with helical flutes in accordance with an alternative preferred embodiment of the present invention; and 
     FIG. 10 shows a front view of a portion of an edge of a fracture band with bihelical flutes in accordance with another alternative preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 through 5 show a misting head poppet  20  in accordance with a preferred embodiment of the present invention, with FIG. 1 showing a front perspective view, FIG. 2 showing a front view (a rear view being identical thereto), FIG. 3 showing a left side view (a right side view being identical thereto), FIG. 4 showing an input end view, and FIG. 5 showing an orifice end view, respectively. FIGS. 6 and 7 shows a cutaway front view of a misting head  22  in accordance with a preferred embodiment of the present invention, FIG. 6 without and FIG. 7 with misting head poppet  20  located therein, respectively. The following discussion refers to FIGS. 1 through 7. 
     Misting head  22  and misting head poppet  20  together make up a misting head system  24 . Misting head  22  is made up of a misting head body  26  having a cylindrical chamber  28  with an inlet  30  at one end and an orifice  34  at the other end. A fluid  32 , typically water, enters chamber  28  through inlet  30  and exits through orifice  34 , where fluid  32  is fractured and rendered into a mist  36  by misting head  22 , i.e., by misting head system  24 . 
     Misting head poppet  20  resides within cylindrical chamber  28 . Poppet  20  is made up of a cylindrical core  38  configured to reside within cylindrical chamber  28 . That is, the length and diameter of core  38  are both less than the length and diameter of chamber  28 , respectively. 
     Poppet  20  is free to reside anywhere within chamber  28 . That is, poppet  20  may at some instances be proximate inlet  30  and at other instances be proximate orifice  34 . A retaining ring  39  or other device or technique well known to those skilled in the art is used to prevent poppet  20  from leaving chamber  28 . 
     Poppet core  38  has an orifice end  40  and an inlet end  42 . In normal operation, pressure within the flow of fluid  32  is sufficient to cause poppet  20  to reside primarily proximate orifice  34 . Orifice end  40  is that end of poppet  20  positioned within chamber  28  more proximate orifice  34 . Inlet end  42 , therefore, is that end of poppet  20  positioned within chamber  28  more proximate inlet  30 , i.e., is that end farther from orifice  34  than orifice end  40 . 
     The presence of poppet  20  within chamber  28  forces fluid  32  passing through chamber  28  to pass through a space  44  between core  38  and an inner wall  46  of chamber  28 . Poppet  20  is configured to vibrate within chamber  28 . Through this vibration, poppet  20  fractures fluid  32  as it passes through space  44 . This fractured fluid  32  is then further fractured by orifice  34  and rendered into mist  36 . 
     In the preferred embodiment of FIGS. 1,  2 ,  3 ,  5 , and  7 , orifice end  40  of poppet  20  has a pair of blind fracture slits  48 . Slits  48  are cut partway across orifice end  40  along a chord. Being blind and partially chordal, slits  48  react with fluid  32  to cause poppet  20  to spin. The shape of slits  48  and the spinning of poppet  20  act to fracture fluid  32 . Since fluid  32  is already fractured by the vibration of poppet  20 , it is further fractured by slits  48  and again further fractured by orifice  34 . For a given pressure, the greater the fracturing of fluid  32 , the finer mist  36  will become. Since ideally mist  36  would be so fine as to be a fog, any increase in fracturing is desirable. 
     Those skilled in the art will appreciate a particular number of fracture slits  48  is not a requirement of the present invention, and that poppet  20  may have any number of fracture slits  48 . When more than one fracture slit  48  is used, the best performance is achieved when these multiple slits  48  are symmetrically placed around the edge of orifice end  40  of core  38 . The use of other than a pair of fracture slits  48  is within the spirit of the present invention. 
     In the preferred embodiment of FIGS. 1,  2 ,  3 ,  5 , and  7 , a chamfer  50  is depicted between poppet core  38  and orifice end  40 . Chamfer  50  allows better seating of core  38  against the end of cylindrical chamber  28 , thus enhancing the fracture characteristics of poppet  20 , and eases the task of inserting poppet  20  into chamber  28  during manufacturing. 
     Similarly, FIGS. 1,  2 ,  3 ,  5 , and  7  depict a chamfer  52  between poppet core  38  and inlet end  42 . Chamfer  52  serves to guide fluid  32  into space  44  between core  38  and inner wall  46  of chamber  28 . Through the use of chamfer  52 , lateral motions of poppet  20  are reduced, thus equalizing the pressure of fluid  32  at orifice  34  and improving the fracture effect thereof. 
     Those skilled in the art, however, will appreciate that the presence of chamfers  50  and/or  52 , and the amount and angle of chamfers  50  and/or  52 , when present, are not requirements of the present invention. 
     Between orifice end  40  and inlet end  42  of cylindrical core  38 , poppet  20  has a fracture band  54 . Fracture band  54  is formed of a cylindrical protrusion (extrusion, projection, or other adaptation)  56  integrally formed onto an outer circumference  58  of cylindrical core  38 . Fracture band  54  has an overall diameter greater than that of cylindrical core  38  and less than that of cylindrical chamber  28 . 
     Fracture band  54  serves to improve the fit of poppet  20  into cylindrical chamber  28 . Because of this improved fit, fracture band  54  centers cylindrical core  38  within cylindrical chamber  28 . This serves to reduce any tendency of poppet  20  to skew within chamber  28  and reduces the likelihood of poppet  20  wedging within chamber  28 . 
     Were fracture band  54  formed solely of cylindrical protrusion  56 , fracture band  54  would effectively occlude space  44  between core  38  and inner wall  46  of chamber  28 . This condition is avoided by forming fracture band  54  of cylindrical protrusion  56  into which a plurality of parallel flutes  60  have been formed. In the preferred embodiment of FIGS. 4 and 5, flutes  60  are depicted as semicircular grooves formed into protrusion  56 . In the preferred embodiment, flutes  60  are formed by etching. That is, a mask resistant to an etchant is imposed upon protrusion  56  and core  38 . The etchant is then applied to etch semicylindrical flutes  60  into protrusion  56 . Those skilled in the art, however, will appreciate that other methods of producing flutes  60 , such as machining, extruding, etc., and other shapes of flutes  60  may be used without departing from the spirit of the present invention. 
     Adjacent flutes  60  are separated by a ridge  62 . The overall diameter of cylindrical protrusion  56  is taken as twice the distance from a central axis of cylindrical core  38  to the outermost edge of any ridge  62 . This overall diameter, as previously described, is such as to allow poppet  20  to move freely within cylindrical chamber  28  without skewing. 
     Fluid  32  passing through space  44  between core  38  and inner wall  46  of chamber  28  is forced to pass through flutes  60 . This passage fractures fluid  32 . Fluid  32 , therefore, is fractured by the vibration of poppet  20  before flutes  60 , is further fractured by flutes  60  of fracture band  54 , is further fractured by the vibration of poppet  20  after flutes  60 , is further fractured by fracture slits  48  and the rotation of poppet  20 , and is further fractured by orifice  34 . The result of this multi-stage fracturing process is the rendering of fluid  32  into mist  36  as a fine fog. 
     The forming of flutes  60  in protrusion  56  affects the fracturing action of poppet  20 . FIGS. 8,  9 , and  10  show magnified front views of portions of edges of differing fracture bands  54  and demonstrate variations in the forming of flutes  60  in accordance with preferred embodiments of the present invention. The following discussion refers to FIGS. 7,  8 ,  9 , and  10 . 
     FIG. 8 demonstrates longitudinal flutes  60 ′, i.e., substantially parallel flutes  60  longitudinally formed into fracture band  54 . The axes of longitudinal flutes  60 ′ are parallel to a central axis of core  38 . Longitudinal flutes  60 ′ fracture fluid  32  without imparting additional motion to core  38 . 
     FIG. 9 demonstrates helical flutes  60 ″, i.e., generally parallel flutes  60  helically formed into fracture band  54 . The axes of helical flutes  60 ″ form helices around the circumference of protrusion  56  in a spiral direction  64 . Helical flutes  60 ″ fracture fluid  32  while imparting a rotational motion to core  38 . Depending upon spiral direction  64 , this rotational motion may augment or detract from the rotational motion imparted by fracture slits  48 . The use of helical flutes  60 ″, therefore, is a means for controlling the overall fracture characteristics of poppet  20 . 
     FIG. 10 demonstrates bihelical flutes  60 ′″, i.e., two sets of generally parallel flutes  60  independently formed into fracture band  54 . The axes of one set of flutes  60  form helices around the circumference of protrusion  56  in a first spiral direction  64 , while the axes of the other set form helices in a second spiral direction  66  opposing first spiral direction  64 . That is, flutes  60  spiraling in second spiral direction  66  spiral around cylindrical protrusion  56  in an opposite spiral direction from flutes  60  spiraling in first spiral direction  64 . Bihelical flutes  60 ′″ fracture fluid  32  without imparting additional rotational motion to core  38 , but while imparting increased vibrational motion to core  38  over longitudinal flutes. 
     Those skilled in the art will appreciate that the present invention requires no specific form for flutes  60 , other than a form which communicates fluid  32  through space  44 , and that the use of longitudinal flutes  60 ′, helical flutes  60 ″, bihelical flutes  60 ′″, and other forms of flutes  60  is within the spirit of the present invention. 
     In summary, the present invention teaches an improved misting head poppet  20 . Within poppet  20 , cylindrical protrusion  56  is configured to inhibit the lateral movement of poppet  20  and prevent poppet  20  from becoming cocked within misting head chamber  28 . Within poppet  20 , cylindrical protrusion  56  is also configured to center poppet  20  within misting-head chamber  28 , thus stabilizing the pressure of fluid  32  at orifice  34  to produce a more uniform mist  36 . Poppet  20  also has a plurality of flutes  60  formed on cylindrical protrusion  56  to produce fracture band  54  and fracture fluid  32 , thus adding to the overall fracture of fluid  32  and rendering fluid  32  into a finer mist  36  than would otherwise be possible for a given pressure. 
     Although the preferred embodiments of the invention have been illustrated and described in detail, it will be readily apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.