Abstract:
A cone-shaped air flow system has improved efficiency, increased plenum chamber exit air flow speeds and reduced noise levels in comparison to box-shaped and triangular air flow systems. The heater may be of half or full cone configuration for perimeter or central plenum locations, respectively.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to air handling equipment and more particularly concerns heat exchange systems. 
     Known heat exchange systems are generally box-shaped and perform with efficiencies that can be quantitatively or experientially determined. Recently, a triangular air flow system was developed which orients heating coils in double or compound angles in relation to its fan in order to increase heating efficiency. The triangular air flow system in theory increases the velocity of air flowing directly through its heating coils and reduces bounce-back air turbulence, noise and static pressure on its fan. Based on tests of the triangular air flow system, its plenum chamber exit air flow speeds are in the order of 700 fpm and its noise levels are in the order of 64-67 db, compared to speed and noise level ranges of 700 to 900 fpm and 64-67 db for a variety of box-shaped air flow systems. 
     It is, therefore, an object of the present invention to provide an air flow system having improved efficiency in comparison to box-shaped and triangular air flow systems. Another object of the present invention is to provide an air flow system having increased plenum chamber exit air flow speeds in comparison to box-shaped and triangular air flow systems. A further object of the present invention is to provide an air flow system having reduced noise levels in comparison to box-shaped and triangular air flow systems. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, a conical air flow system is provided which affords improved efficiency, increased plenum chamber exit air flow speeds and reduced noise levels in comparison to box-shaped and triangular air flow systems. 
     In a first embodiment, the conical air flow system has a housing in the shape of a diametrically divided or half-cone. An air inlet port into the housing is defined by the semi-circular base of the cone. At least one air exit port is located in the side wall of the cone. A fan induces vortical air flow through the inlet port into the housing. Preferably, the housing has two air exit ports symmetrically spaced in the side wall of the half-cone. The base angle of the half-cone is in a range of 40-80°. 
     In a second embodiment, the conical air flow system has a housing in the shape of a full cone. An air inlet port into the housing is defined by the circular base of the cone. At least one air exit port is located in the side wall of the cone. A fan induces vortical air flow through the inlet port into the housing. Preferably, the housing has three air exit ports in the side wall of the housing symmetrically spaced in a 360° array. The cone has a base angle in a range of 40-80°. 
     In either embodiment, the total area of the air exit ports is at least as great as the area of the air inlet port or the rotational area covered by the fan blades, whichever is smaller. The contours and angles result in an air flow system which has plenum chamber exit air flow speeds in a range of 1000-1350 fpm, or 30 to almost 100% higher speeds than the triangular heater, and which operates at noise levels in a range of 55-58 db, which is approximately 5 db lower than the triangular heater. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is a top plan view of a half-cone embodiment of a conical air flow system; 
         FIG. 2  is a cross-sectional view taken along the line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is side elevation view of the half-cone embodiment of  FIG. 1 ; 
         FIG. 4  is a top plan view of a full-cone embodiment of a conical air flow system; 
         FIG. 5  is a cross-sectional view taken along the line  5 - 5  of  FIG. 4 ; 
         FIG. 6  is side elevation view of the full-cone embodiment of  FIG. 4 ; 
         FIG. 7  is a top plan view of another half-cone embodiment of a conical air flow system; 
         FIG. 8  is a cross-sectional view taken along the line  8 - 8  of  FIG. 7 ; and 
         FIG. 9  is side elevation view of the half-cone embodiment of  FIG. 7 . 
     
    
    
     While the invention will be described in connection with preferred embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments or to the details of the construction or arrangement of parts illustrated in the accompanying drawings. 
     DETAILED DESCRIPTION 
     Turning first to  FIGS. 1-3 , a first half-cone embodiment of the air flow system is illustrated. A housing  10  has the shape of a diametrically divided cone  11  with an outwardly extending radial mounting flange  13  along its base edge  15 . As shown, the base edge  15  defines an air inlet port  17  into the housing  10 . However, the air inlet port  17  could be made smaller and shaped differently than the semi-circular base edge  15  of the divided cone  11  by extending the flange  13  inwardly to the desired perimeter of the air inlet port  17 . As best seen in  FIGS. 2 and 3 , the apex  19  of the divided cone  11  is slightly blunted. As shown, two air exit ports  21  extend through the side wall  23  of the housing  10 . A fan  25  is positioned below the plane of the base edge  15  for rotation about a vertical axis  27  through the center of the air inlet port  17  of the half-cone  11  to induce vortical air flow in the housing  10 . The cone  11  has a base angle  29  in a range of 40-80° and, as shown, 60°. Preferably, the air exit ports  21  are symmetrically spaced in the side wall  23  of the cone  11  with the center lines  31  of the ports  21  spaced at 90-120°. As shown, the center lines  31  are spaced 45° from the diametric edges  33  of the housing  10  and the ports  21  span 60° across their centerlines  31 . However, the air exit ports  21  can be of any shape and in any location in the side wall  23  as long as their total area is at least as great as the area of the air inlet port  17  or the rotational area covered by the blades of the fan  25 , whichever is smaller. 
     The housing flange  13  is mounted on the fan housing (not shown) with the diametric edges  33  butted against a surface of the cabinet (not shown) in which the air flow system is to be contained. The cabinet surface completes the half-conical housing  10 . As vertical flow is induced in the housing  10  by the fan  25 , the conical housing  10  pressurizes the induced vertical air flow, thereby removing any air pockets produced by the fan  25 . As the air stream exits the housing  10  through the exit ports  21 , the treated air is carried farther, thus improving airflow capabilities and velocities. The shape of the half-cone  11  allows the housing  10  to be installed in a variety of orientations with increased stability. The conical system also reduces material costs compared to the known triangle and conventional body systems. 
     Turning now to  FIGS. 4-6 , a full-cone embodiment of the air flow system is illustrated. A housing  40  has the shape of a cone  41  with an outwardly extending radial mounting flange  43  along its base edge  45 . As shown, the base edge  45  defines a circular air inlet port  47  into the housing  40 . However, the air inlet port  47  could be made smaller and shaped differently than the circular base edge  45  of the cone  41  by extending the flange  43  inwardly to the desired perimeter of the air inlet port  47 . As best seen in  FIGS. 5 and 6 , the apex  49  of the cone  41  is slightly blunted. As shown, three air exit ports  51  extend through the side wall  53  of the housing  40 . A fan  55  is positioned below the plane of the base edge  45  for rotation about the vertical axis  57  of the cone  41  to induce vortical air flow in the housing  40 . The cone  41  has a base angle  59  in a range of 40-80° and, as shown, 60°. Preferably, the air exit ports  51  are symmetrically spaced in the side wall  53  of the cone  41  with the center lines  61  of the ports  51  spaced at 120° intervals. However, the air exit ports  51  can be of any shape and in any location in the side wall  53  as long as their total area is at least as great as the area of the air inlet port  47  or the rotational area covered by the blades of the fan  55 , whichever is smaller. 
     The housing flange  43  is mounted on the fan housing (not shown) in a cabinet (not shown) in which the air flow system is to be contained. As vortical flow is induced in the housing  40  by the fan  55 , the conical housing  40  pressurizes the induced vortical air flow, thereby removing any air pockets produced by the fan  55 . As the air stream exits the housing  40  through the exit ports  51 , the treated air is carried farther, thus improving airflow capabilities and velocities. Installation is limited only to the base of the cone  41  but the full-cone housing  40  can be placed in horizontal or vertical orientation. The conical system also reduces material costs compared to the known triangle and conventional body systems. In the full-cone embodiment  40  as seen in  FIGS. 4-6 , if the height of the cone  41  is the same as the height of the cone  11  of the half-cone embodiment  10  seen in  FIGS. 1-3 , a larger volume of air is transferred. 
     Turning finally to  FIGS. 7-9 , another half-cone embodiment of the air flow system is illustrated. A housing  70  has the shape of a diametrically divided cone  71  with an outwardly extending radial mounting flange  73  along its base edge  75 . As shown, the base edge  75  defines an air inlet port  77  into the housing  70 . However, the air inlet port  77  could be made smaller and shaped differently than the semi-circular base edge  75  of the divided cone  71  by extending the flange  73  inwardly to the desired perimeter of the air inlet port  77 . As best seen in  FIGS. 8 and 9 , the apex  79  of the divided cone  71  is slightly blunted. As shown, one air exit port  81  extends through the side wall  83  of the housing  70 . A fan  85  is positioned below the plane of the base edge  75  for rotation about a vertical axis  87  through the center of the air inlet port  77  of the half-cone  71  to induce vortical air flow in the housing  70 . The cone  71  has a base angle  89  in a range of 40-80° and, as shown, 60°. Preferably, the air exit port  81  is symmetrically spaced in the side wall  83  of the cone  71  with the center line  91  of the port  81  at the midpoint of the half-cone arc. As shown, the side edges  93  of the exit port  81  are approximately 135° apart. However, the air exit ports  81  can be of any shape and in any location in the side wall  83  as long as their total area is at least as great as the area of the air inlet port  77  or the rotational area covered by the blades of the fan  85 , whichever is smaller. 
     The housing flange  73  is mounted on the fan housing (not shown) with the diametric edges  73  butted against a surface of the cabinet (not shown) in which the air flow system is to be contained. The cabinet surface completes the half-conical housing  70 . As vortical flow is induced in the housing  70  by the fan  85 , the conical housing  70  pressurizes the induced vortical air flow, thereby removing any air pockets produced by the fan  85 . As the air stream exits the housing  70  through the exit port  81 , the treated air is carried farther, thus improving airflow capabilities and velocities. The shape of the half-cone  71  allows the housing  70  to be installed in a variety of orientations with increased stability. The conical system also reduces material costs compared to the known triangle and conventional body systems. 
     In each of the above embodiments  10 ,  40  or  70  for many of their applications, the height of the cone  11 ,  41  or  71  will typically be approximately 14″, but the height can vary greatly as long as the base angle  29 ,  59  or  89  is in the 40-80° range and optimally 60°. As shown, the air exit ports  21 ,  51  or  81  are substantially centered on the heights of the cones  11 ,  41  or  71  but need not necessarily be so centered. While conical systems will normally employ half (180°) or full (360°) cone housings, custom conical housings of anywhere from 90° to 360° can be formed as long as the total area of their exit ports is at least as great as the area of their air inlet port or the rotational area covered by the blades of their fan, whichever is smaller, and their base angle is in the 40°-80° range. Half-cone embodiments, such as the embodiments  11  and  71  shown in  FIGS. 1-3  and  7 - 9 , respectively, are best suited for use on the perimeter of the system cabinet. Full-cone embodiments, such as the embodiment  40  shown in  FIGS. 4-6 , are best suited for use in the center of the system cabinet. Custom angular embodiments are used in unique cabinet applications. 
     Thus, it is apparent that there has been provided, in accordance with the invention, a cone-shaped air flow system that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art and the light of foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit of the appended claims.