Abstract:
A fuel equalization system includes a filter box for accepting an air stream and a fuel stream, the air stream and the fuel stream mixing to form a mixed air/fuel stream. A blower is provided that has an inlet for accepting the mixed air/fuel stream from the filter box. An air deflection member is positioned in the path of the mixed air/fuel stream, between the filter box and the inlet, so as to reduce the turbulence of the mixed air/fuel stream.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation-in-Part of U.S. Utility patent application Ser. No. 11/432,001 filed on May 11, 2006 and claims the benefit of U.S. Provisional Application Ser. No. 60/ 680,805, filed on May 13, 2005, both of which are incorporated herein by reference in their entireties. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention generally relates to forced air/fuel burner apparatus, and more particularly relates to a fuel equalization system that continues to supply a proper air/fuel ratio to such apparatus even during times of decreased or blocked air flow at a blower outlet. 
       BACKGROUND OF THE INVENTION 
       [0003]    Burners are utilized in many integrated systems, such as in boilers, furnaces and water heater applications. These burners are typically fed an enriched air stream containing a predetermined concentration of fuel mixed therein. Of great importance, therefore, is the ability of the system to maintain a proper air/fuel mixture during operation of the system. 
         [0004]    Typically, a filter box includes one or more orifices to accept incoming air and fuel streams, which are mixed within the box by motion of the air through the box. The filter box may include various baffles, blades, and other structures to enhance mixing of the air and fuel. A blower is operatively connected to the filter box, and propels the air/fuel mixture from the filter box, to an integrated burner. Any blockage of the incoming air or fuel streams, or of the flue leading to the burner, will cause a change in the air/fuel mixture being fed to the burner, with a corresponding potential for the harmful buildup of CO. 
         [0005]    Known systems oftentimes employ one or more sensors within the filter box coupled with a variable speed blower to regulate the introduction of the air/fuel mixture to the burner. While these systems operate reasonably well during normal times, they suffer under blocked-flue or blocked-air inlet conditions due to the swirling air currents created by these adverse conditions. That is, known systems arrange the air/fuel inlet orifice(s) and sensors adjacent to, or near, the blower inlet, therefore the turbulence created at the air inlet by a blockage creates an ‘implied’ flow in and around the sensors. Thus, during times of blockages, the sensors of known systems are incapable of accurately controlling the desired air/fuel mixture, due to the swirling and turbulent implied flows washing over the sensors. 
         [0006]    Known systems are therefore unable to accurately control the air/fuel mixture during times when the air inlet, or flue, is partially or completely blocked. 
         [0007]    With the foregoing problems and concerns in mind, it is the general object of the present invention to provide a fuel equalization system that can accurately detect and respond to situations of air blockage so as to maintain safe air/fuel mixtures. 
       SUMMARY OF THE INVENTION 
       [0008]    It is one object of the present invention to provide a fuel equalization system. 
         [0009]    It is another object of the present invention to provide a fuel equalization system, which is capable of maintaining a desired air/fuel ratio. 
         [0010]    It is another object of the present invention to provide a fuel equalization system which is capable of maintaining a desired air/fuel ratio even during times of blocked air flow. 
         [0011]    It is another object of the present invention to provide a fuel equalization system which reduces the turbulence of a blocked air flow. 
         [0012]    A further object of the invention is to position the air and fuel inlet orifices some distance from the blower inlet, thereby isolating the air and fuel inlet orifices from excessive turbulence caused by any blockages. 
         [0013]    A further object of the invention is to decrease the number of clips that are engaged about the respective connected adjacent flange portions to prevent leakage. 
         [0014]    A further object of the invention is to provide a fuel equalization system which substantially eliminates the creation of harmful gas build-up during times of partially or completely blocked air flows. 
         [0015]    In accordance, therefore, with one embodiment, it is an object of the present invention to provide a fuel equalization system that includes a filter box for accepting an air stream and a fuel stream, the air stream and the fuel stream mixing within the filter box to form a mixed air/fuel stream; a blower that has an inlet for accepting the mixed air/fuel stream from the filter box and an outlet for forcing the air/fuel mixture to a burner; and at least one air deflection member positioned in the path of the mixed air/fuel stream, between the filter box and the blower inlet, so as to reduce the turbulence of the mixed air/fuel stream. 
         [0016]    These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  illustrates an exploded view of a fuel equalization system according to one embodiment of the present invention. 
           [0018]      FIG. 2  is a partially exploded view of the fuel equalization system of  FIG. 1 , in isolation. 
           [0019]      FIG. 3  illustrates a schematic side view of a fuel equalization system according to another embodiment of the present invention. 
           [0020]      FIG. 4  is a sectional assembled partial view of the fuel equalization system shown in  FIGS. 1 and 2 , taken along the section line  4 - 4  shown in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]      FIG. 1  illustrates an exploded view of a fuel equalization system  10 , according to one embodiment of the present invention. As shown in  FIG. 1 , the fuel equalization system  10  includes a filter box  12  and a blower  14 . The blower  14  sucks an air/fuel mixture from the filter box and forces the air/fuel mixture to a burner assembly  16 , which is operatively connected to a boiler apparatus  18 . 
         [0022]    It will be readily appreciated that while the boiler apparatus  18  has been described in connection with  FIG. 1 , the present invention is not so limited in this regard as the blower  14  may be connected to any suitable apparatus without departing from the broader aspects of the present invention. 
         [0023]      FIG. 2  illustrates the fuel equalization system in isolation. As shown in  FIG. 2 , the filter box  12  defines an inner box  20  having an air orifice and a fuel entry  22 . A duct section  24  connects an outlet of the filter box  12  to the inlet of the blower  14 . An air stream and a fuel stream are respectively directed through the air orifice and the fuel entry  22  via known means, are mixed together in the inner box  20 , and this mixture is then sucked through the duct section  24  by the blower  14 , which blows the mixture into the burner assembly  16 . 
         [0024]    It is an important aspect of the present invention that the air orifice and fuel entry  22  are not positioned adjacent to the blower inlet  26 , as is typically known in the art. Instead, the present invention arranges the air orifice and fuel entry  22  as far away as possible from the blower inlet  26 , thereby isolating the air orifice and fuel entry  22 , and any associated sensors, from the turbulence that may be caused by any air/fuel stream blockage at the blower outlet. 
         [0025]    A static impeller  28  is arranged within the duct section or spool piece  24  and adjacent the blower inlet  26 . As shown, the impeller  28  is slightly smaller in outer diameter than the inner diameter of the enclosing spool piece. When the outlet  30  of the centrifugal blower  14  is partially or completely blocked, the resultant swirling air/fuel stream ‘backs up’ along the axis of the blower and is redirected back through the impeller  28  and through the duct section  24 . The vanes  32  of the impeller  28  effectively reduce or eliminate the velocity and rotation of the redirected air/fuel stream passing therethrough. 
         [0026]    The velocity and rotation of the re-directed air/fuel stream is further reduced or eliminated by the inclusion of a straightening blade  34 , also formed in the duct section  24 . As shown in  FIG. 2 , the straightening blade  34  is a generally flat piece of metal or plastic, and is preferably arranged along a diameter of the duct section  24 . The straightening blade  34  acts as a baffle to intercept and further restrain the swirling air/fuel stream, prior to the redirected air/fuel stream entering the filter box  12 . 
         [0027]    It is therefore another important aspect of the present invention that the static impeller  28  and the straightening blade  34  effectively reduce or eliminate any implied air flow into the filter box. That is, the static impeller  28  and the straightening blade  34  reduce the velocity and swirling nature of the air/fuel stream that is redirected back through the duct section  24 . When coupled with positioning of the air orifice and fuel entry  22  a distance away from the blower inlet  26 , the static impeller  28  and the straightening blade  34  effectively isolate the air orifice and fuel entry  22  from the implied air flow that is generated by the blockage of the blower outlet  30 . Thus, any sensors mounted adjacent the air orifice and fuel entry  22  do not suffer from imprecise readings, and the fuel equalization system  10  can therefore be operated even in conditions of nearly complete blockage of the blower outlet  30 , or the like. 
         [0028]    While the straightening blade  34  in  FIGS. 1 and 2  is shown as being oriented substantially vertically, and extending substantially the entire diameter and length of the duct section  24 , the present invention is not limited in this regard. Indeed, the straightening blade  34  need not extend vertically, or across the entire diameter of the duct section or along the entire length of the duct section  24 , nor does the straightening blade  34  need to extend precisely along a diameter of the duct section  24 , in order to substantially reduce or eliminate the velocity and swirling nature of the redirected, or implied, air/fuel stream. 
         [0029]    The embodiment shown and described in connection with  FIGS. 1 and 2  has depicted a centrifugal blower  14 , however the present invention is not limited in this regard.  FIG. 3  illustrates a schematic side view of a fuel equalization system  50  according to another embodiment of the present invention. As shown in  FIG. 3 , the fuel equalization system  50  includes a squirrel cage blower  52  operably connected to a filter box  54 . An air orifice and fuel entry  56  is formed in the filter box  54  and provides the fuel equalization system  50  with the required air/fuel stream in a well-known manner. 
         [0030]    Also shown in  FIG. 3  is a squirrel cage impeller  58 , which is specially equipped with an air deflector plate  60 . The deflector plate  60  is preferably arranged within the throat of the impeller  58  and is shaped to capture the majority of the redirected air/fuel flow, created by a blockage of the unillustrated blower outlet, or the like, back into the blower  52 . For example, the deflector plate  60  can be shaped as a truncated cone opened at both ends. In this manner, any swirling, high velocity and redirected air/fuel stream created by a blockage of the blower outlet is largely kept within the blower  52 , and consequently does not adversely affect the air orifice and fuel entry  56 , or any related sensors disposed within the filter box  54 . 
         [0031]    The embodiment shown in  FIG. 3  also arranges the air orifice and fuel entry  56  as far away from the blower inlet  62  as possible, similar to the embodiment of  FIGS. 1 and 2 , so as to further isolate the air orifice and fuel entry  56  from the effects of any implied air flow. 
         [0032]    A straightening blade, or baffle,  64  is located in the filter box  54  in much the same manner that the straightening blade  34  is arranged in the embodiments of  FIGS. 1 and 2 . That is, the straightening blade  64  is located so as to substantially bisect the incoming redirected air/fuel stream, thereby reducing its velocity and swirling nature. Alternatively, as shown in  FIG. 4 , the straightening blade  64  can extend into the impeller  28  or  58 , which is rotatable with reference to the structure supporting the straightening blade. 
         [0033]    Although the embodiments of  FIGS. 1-4  have illustrated the present invention as it is implemented in connection with a centrifugal blower system, and a squirrel cage blower system, the present invention is not so limited in this regard. Indeed, regardless of the type of blower that is employed, or the nature of the apparatus to which the blower provides the air/fuel mixture, the present invention envisions disposing a straightening blade/baffle within the path of any redirected air/fuel stream. The baffle itself may have a number of possible configurations and dimensions, provided that it extends along the path of any redirected air/fuel stream so as to reduce the velocity of the redirected air/fuel stream, as well as reducing the swirling nature of the redirected air/fuel stream. 
         [0034]    The use of the static impeller  28 , or the air deflector plate  60 , in combination with locating the air orifice and fuel entry  56  as far as possible from the blower inlet  26 / 62 , also assists in reducing the velocity of the redirected air/fuel stream, as well as reducing the swirling nature of the redirected air/fuel stream. 
         [0035]    Thus, the present invention substantially eliminates the erroneous sensor readings and possible CO contamination stemming from a blocked blower outlet, or the like. By removing the effects of the implied air flow from the present fuel equalization system, the present invention is capable of properly regulating the air/fuel mixture that is provided to a blower and burner assembly, up to and including properly regulating the air/fuel mixture even during times of near complete blockage of the blower outlet or burner flue. 
         [0036]    While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims.