Abstract:
A splash fill arrangement for use in a direct heat exchange section of a cooling tower is provided. Each splash fill arrangement includes support plates and elongated bars extending there between, which arrangement improves the performance of the splash fill arrangement when installed as a direct heat exchange section of a cooling tower. Certain of the elongated bars between the support plates are angled from the horizontal to improve the air flow capabilities and performance of the direct heat exchange section.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a heat and mass transfer media, or a splash fill arrangement, utilized within the direct heat exchange portion of a cooling tower. More particularly, the present invention relates to a splash fill arrangement for use in a direct heat exchange unit, which could be a cooling tower. 
         [0002]    The heat and mass transfer media, or splash fill arrangement, is generally horizontally oriented with an evaporative liquid, usually water, coursing over the arrangement, usually flowing downwardly, with an air stream directed usually transversely but potentially concurrent or cross current through the splash fill arrangement comprising a direct cooling section. The air interacts with the evaporative liquid for heat and mass transfer. 
       SUMMARY OF THE INVENTION 
       [0003]    The heat and mass transfer media, or splash fill arrangement, of the present invention enhances the thermal efficiency of the direct heat exchanger by providing an arrangement of splash fill components over which air and an evaporative liquid, usually water, pass. The arrangement of splash fill components is comprised of two or more support plates, between which a plurality of elongated bars extend. The elongated bars are positioned at predetermined locations and angles to provide an improved direct heat exchanger. The improved performance of the direct heat exchanger is related to the shape, positioning and angle placement of the elongated bars. By placing the elongated bars of the various preferred shapes at such preferred locations and angles, improved flow of the evaporative liquid, usually water, over the elongated bars occurs. Improved flow of the evaporative liquid includes improved drop formation and flow direction when the evaporative liquid drops leave the elongated bars. Such improved drop formation is combined with improved air flow between and across the elongated bars. This combination of improved drop formation and improved air flow leads to improved heat transfer in the direct heat exchanger. 
         [0004]    When the evaporative liquid passes generally downwardly over the elongated bars of the splash fill arrangement, portions of the evaporative liquid spills from certain of the elongated bars, wraps around certain of the elongated bars and then falls from the bars or both. The cooling air which is usually drawn across the elongated bars by a fan causes some of the evaporative liquid to evaporate and thusly result in mass and heat transfer. 
         [0005]    The cross sectional shape of the splash fill component elongated bar can be of various types, but usually includes rounded corners to allow the evaporative liquid to both flow across portions of and in some embodiments wrap around the cross section of the elongated bar. Such flow improves the heat transfer from the evaporative liquid and the air passing through the splash fill arrangement. 
         [0006]    The splash fill elongated bars are usually angled downwardly from 5 to 45 degrees from the horizontal toward the air inlet side of the splash fill arrangement. This angled orientation of the elongated bars assists in exposing more of the evaporative liquid flowing across the bars to the air moving across the splash fill arrangement, without unduly impeding the air flow. In certain embodiments of the splash fill arrangement of the present invention, most arrays of elongated bars will be angled downwardly from 5 to 45 degrees from the horizontal, while an intermittent array of elongated bars will not be so angled, but rather be at a horizontal orientation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    In the drawings, 
           [0008]      FIG. 1  is a side cross sectional view of a splash fill arrangement in a cooling tower in accordance with a first embodiment of the present invention; 
           [0009]      FIG. 2  is a detailed perspective side view of a portion of a splash fill arrangement in accordance with a first embodiment of the present invention; 
           [0010]      FIG. 3  is a schematic cross sectional view of a splash fill arrangement in accordance with a second embodiment of the present invention; 
           [0011]      FIG. 4  is a schematic cross sectional view of a splash fill arrangement in accordance with a third embodiment of the present invention, and 
           [0012]      FIG. 5  includes schematic views of cross sections of elongated bars of a splash fill arrangement in accordance with three embodiments of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0013]    Referring now to  FIG. 1  of the drawings, a cooling tower is shown at  10 . Cooling tower includes motor  16  which drives fan  12 . Fan  12  causes an air flow inwardly from the sides of cooling tower  10  and accordingly across inlet louvers  18  and exiting upwardly out through the cowling around fan  12 . Other air flow directions and fan arrangements such as coaxial side draw fans that result in air flow across or across and upwardly through splash fill arrangement  20  are part of the present invention. Cooling tower  10  is a direct heat exchanger, as an evaporative liquid, usually water, flows downwardly from water spray nozzles or openings  14 . Such nozzles or openings are placed in a water distribution line. Splash fill arrangement  20  is seen to comprise a generally rectangular support plate  24 . Support plate  24  can be comprised of structural plastic such as PVC, or aluminum or galvanized steel or stainless steel. Support plate  24  includes a plurality of openings to receive and support elongated bars  22 . Although only a single support plate is shown and described, it should be understood that two or more support plates would usually be utilized in a cooling tower splash fill arrangement. The openings in support plate  24  are sized to correspond to the cross section of elongated bars  22  to appropriately support elongated bars in cooling tower  10 . Elongated bars  22  themselves may be comprised of structural plastic such as PVC, or aluminum or galvanized steel or stainless steel. Support plate  24  is shown to be of a generally rectangular and generally planar structure; however, it should be understood that based on design of installation needs support plate  24  may be of a square or trapezoidal structure as well. When installed splash fill arrangement  20  is installed in a direct heat exchange unit, usually as a component of a cooling tower, an evaporative liquid, usually water, flows downwardly onto a top portion of splash fill arrangement  20  and exits from a bottom portion thereof. Inlet louvers  18  help prevent water from exiting cooling tower  10  in a sideways direction without passing through the entire splash fill arrangement  20 . First side edge of cooling tower  10  with inlet louvers  18  is typically an air inlet edge wherein air is forced or drawn cross-current to the evaporative liquid downward flow to exit from second side edge  19 . Such combination of evaporative liquid down flow and cross-current air flow acts to remove heat from the evaporative liquid by both a heat and mass transfer operation. It should be understood that air flow may be somewhat counter current or con-concurrent with the evaporative liquid downward flow, depending on the design of the direct heat exchange unit and the fan placement. 
         [0014]    Referring now to  FIG. 2 , a first embodiment of a splash fill arrangement is shown as comprising support plate  30  and elongated bars  32 . The composition of support plate  30  and elongated bars  32  are as set forth above. However, elongated bars  32  are shown to be installed in support plate  30  at an angle to the horizontal. Such angle is preferably between 5 and 45 degrees. Such angled installation of elongated bars  32  is designed to improve the heat exchanging performance of the direct heat exchange system into which the splash fill arrangement is installed. Air flow is depicted as from left to right in  FIG. 2  as shown by the arrow. Water flow is generally downward. This angled orientation of elongated bars  32  assists in exposing more of the evaporative liquid flowing across elongated bars  32  to the air moving across the splash fill arrangement, without unduly impeding the air flow. 
         [0015]    Referring now to  FIG. 3 , a second embodiment of a splash fill arrangement is shown as comprising support plate  40  and arrays of angled elongated bars  44  and array of horizontal elongated bars  46 . Support plate  40  itself is seen to be hung or otherwise supported by support bars  42  which can be comprised of structural plastic, or aluminum or galvanized steel or stainless steel. The composition of support plate  40  and elongated bars  44  and  46  are as set forth above. However, elongated bars  44  in the upper array are shown to be installed in support plate  40  at an angle to the horizontal. Such angle is preferably between 5 and 45 degrees. Horizontal elongated bars  46  between the arrays of elongated bars  44  are seen to be installed at a zero degree angle to the horizontal. Such combined angled and horizontal installation of elongated bars  44  and  46 , respectively, is designed to improve the heat exchanging performance of the direct heat exchange system into which the splash fill arrangement is installed. 
         [0016]    Air flow is depicted as from left to right in  FIG. 3  as shown by the arrow. Water flow is generally downward. This angled orientation of elongated bars  44  assists in exposing more of the evaporative liquid flowing across elongated bars  44  to the air moving across the splash fill arrangement, without unduly impeding the air flow. The horizontal orientation of elongated bars assists in directing the airflow in generally horizontal direction. 
         [0017]    The vertical gap  43  between elongated bars  44  and  46  varies such that the size of gap  43  near top edge  47  of support plate  40  is smallest and gradually increases toward the bottom edge  48 . The gradual increase in the vertical gap  43  between elongated bars  44  and  46  helps to counteract the difference in air pull pressure along the outlet side  59  by the fan  12  that is generally located near the corner of top edge  47  and outlet side  59 . 
         [0018]    Referring now to  FIG. 4 , a third embodiment of a splash fill arrangement is shown as comprising support plate  50  and an inlet array of elongated bars  54 , a central array of elongated bars  52  and an outlet array of elongated bars  56 . The composition of support plate  50  and elongated bars  52 ,  54  and  56  are as set forth above. However, elongated bars  54  in the inlet array are shown to be installed in support plate  50  at an upward angle to the horizontal. Such angle is preferably between 5 and 45 degrees. Such angled installation of elongated bars  54  is designed to improve the heat exchanging performance of the direct heat exchange system into which the splash fill arrangement is installed by assisting in keeping more of the generally downward flowing water from exiting the splash fill arrangement through inlet side  57 . Elongated bars  52  in the center array are seen to be installed at a downward degree angle to the horizontal. Such angle is preferably between 5 and 45 degrees. Elongated bars  56  in the outlet array are shown to be installed in support plate  50  at an increased downward angle to the horizontal. Such angle is preferably between 20 and 50 degrees. Such angled installation of elongated bars  56  is designed to improve the heat exchanging performance of the direct heat exchange system into which the splash fill arrangement is installed by assisting in keeping more of the generally downward flowing water from exiting the splash fill arrangement through outlet side  59 . Air flow is depicted as from left to right in  FIG. 4  as shown by the arrow. Water flow is generally downward. This angled orientation of center section elongated bars  52  assists in exposing more of the evaporative liquid flowing across elongated bars  52  to the air moving across the splash fill arrangement, without unduly impeding the air flow. 
         [0019]    Referring now to  FIG. 5 , five preferred embodiments of the elongated bars are shown at  60 ,  62 ,  63 ,  64  and  70 . Elongated bar  60  is seen to have a generally smooth edged rectangular cross sectional configuration. Elongated bar  62  is seen to have a generally smooth edged rectangular cross section; however, two ridges  66  and  68  extend from a lower leading edge of elongated bar  62 . Elongated bar  64  is seen to have a generally smooth edged rectangular cross sectional configuration; however, the top surface thereof is raised from a flat arrangement and the bottom surface thereof is indented from a flat arrangement. Elongated bar  63  is seen to have a generally smooth edged rectangular cross sectional configuration; however, the top surface thereof is indented from a flat arrangement and the bottom surface thereof is lowered from a flat arrangement. Elongated bar  70  is seen to have a generally smooth edge rectangular cross sectional configuration; however, the bottom surface thereof includes an opening  72 .