Abstract:
A cooling tower fill support grid assembly and method of use which includes multiple cooling tower assembly fill hangers, each having a grid pattern that defines multiple grid openings of selected size. In one embodiment an anchor rivet pin extends from the horizontal grid members upwardly and disproportionally spaced-apart from the vertical grid members, into each grid opening. The anchor rivet pins are located off-center on the horizontal grid members between respective vertical grid members for engaging elliptical splash fills that are inserted in the aligned grid openings of adjacent assembly fill hangers in a first configuration. Once so inserted, the elliptical splash fills are rotated ninety-degrees into contact and engagement with the anchor rivet pins in a second, installed configuration. In another embodiment resilient, perforated plate splash fills are seated in the fill hangers and are removably retained between the respective vertical grid members by notches or nibs provided in or on the vertical grid members. The top edge of each assembly fill hanger typically has a notched flange for stacking and seating on the cooling tower frame and holes are provided in the flange for receiving nails.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of and incorporates by reference U.S. Provisional Application Ser. No. 60/713,085, Filed Sep. 1, 2005. 

   FIELD OF THE INVENTION 
   This invention relates to contacting apparatus for mass and heat transfer operations and more particularly, to support grids or fill hangers for receiving, engaging and supporting elliptical fill splash bars and/or resilient, perforated plates, typically in cooling tower applications. Air-liquid contact in cooling towers is optimized by providing a high volume void to effect a low resistance to fluid flow, along with a large surface area per unit of volume and low density to facilitate optimum contact surface with minimum weight. The fill support grids or hangers of this invention are designed to achieve this end and are disposed in a stacked assembly designed for quick and easy attachment to a two by four wooden framework in the cooling tower, without the necessity of using retainer clips or fastener tabs to secure the fill structure in the respective fill hanger grid openings or the fill hangers to the cooling tower framework. 
   SUMMARY OF THE INVENTION 
   The cooling tower fill support grid assembly of this invention is designed to accept and mount elliptical splash bars, grids and/or resilient, perforated plate fill with high economy and efficiency, since no external clips or fasteners are required to secure the elliptical splash bars or grids or the perforated plate fill in the respective aligned hanger grid openings of the respective support grid assembly fill hanger elements. The support grid assembly includes an assembly or collection of spaced-apart, stacked, typically parallel sets of fill hangers, each having a hanger grid typically constructed of vertical and horizontal grid members that are spaced-apart to define hanger grid openings of selected size. While the grid members can be skewed instead of parallel, a parallel grid member orientation is preferred. In one embodiment, an anchor rivet pin extends upwardly from each of the horizontal grid members into a corresponding hanger grid opening in off-center relationship with respect to the adjacent vertical grid members. This disproportionate positioning or spacing of the anchor rivet pins leaves a large space between each anchor rivet pin and one of the corresponding vertical grid members for insertion of an elliptical splash fill having a splash fill grid defining splash fill grid openings. After insertion with the major or long axis vertically oriented, the elliptical splash fills are typically rotated ninety-degrees in the aligned hanger grid openings and caused to engage the anchor rivet pins, each at an aligned elliptical splash fill grid opening, to secure the elliptical splash fills in place in the cooling tower fill support grid assembly. In another embodiment, resilient, perforated “gull wing” plates are inserted in the respective hanger grid openings and are removably secured in place between the respective vertical grid members  9  by nibs or slots provided on or in the grid members. In a preferred embodiment of the invention the top edge of each fill hanger is shaped to define an L-shaped flange provided with spaced-apart openings to receive fasteners such as nails for securing the fill hangers to a 2×4 frame without the necessity of using mounting clips or retainers. Spaced-apart notches may also be provided on the fill hanger flange for securing the fill hangers to each other in stacked, spaced-apart relationship. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood by reference to the accompanying drawings, wherein: 
       FIG. 1  is a perspective view of a first embodiment of the cooling tower fill support grid assembly of this invention; 
       FIG. 2  is a perspective view of a typical elliptical fill element inserted in the fill support grid assembly illustrated in  FIG. 1 ; 
       FIG. 3  is a front elevation, partially in section, of the top portion of a typical fill hanger with the elliptical splash fills in place, more particularly illustrating a preferred placement and manipulation of the elliptical splash fills in the hanger grid of the fill hanger; 
       FIG. 4  is a perspective view, partially in section, of a typical fill hanger illustrated in  FIG. 1 ; 
       FIG. 5  is a perspective view, partially in section, of a typical stacked mounting of adjacent fill hangers in the fill support grid assembly and an alternative configuration for the anchor rivet pins; 
       FIG. 6  is a perspective view of a second embodiment of the fill support and assembly of this invention using resilient, perforated plate fills in a first plate mount configuration; and 
       FIG. 7  is a perspective view of a second embodiment of the fill support and assembly using resilient, perforated plate fills in a second plate mount configuration. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring initially to  FIGS. 1 and 4  of the drawings, a typical fill support grid assembly of this invention is illustrated by reference numeral  1 . The fill support grid assembly  1  includes a pair or set of fill hangers  6 , mounted in spaced-apart, generally parallel relationship with respect to each other on an assembly frame  2  ( FIG. 1 ). The assembly frame  2  is typically constructed of wooden frame members  3 , such as 2×4 boards that are secured to each other by frame member fasteners  4 . The frame member fasteners  4  are typically nails or screws and the fill hangers  6  are attached to the frame members  3  at the respective grid flanges  11 , shaped in the top edges thereof. Accordingly, in a preferred embodiment of the invention the fill hangers  6  are molded in a selected cross-sectional configuration of a suitable plastic material such as polyethylene and polypropylene and most preferably, nylon, or they may be constructed of steel having a plastic coating. The grid flanges  6  are typically L-shaped, as in the configuration of angle iron and typically have spaced-apart top openings  11   a  provided in the horizontal flange element and spaced-apart side openings  11   b  in the vertical element of the grid flange  6 . The top openings  11   a  and side openings  11   b  may be reinforced by thickened rings and are located and sized to accommodate nails or screws and quickly and efficiently mount the fill hangers  6  on the respective frame members  3  of the assembly frame  2 , as hereinafter further described. As further illustrated in  FIG. 1 , the fill hangers  6  can be aligned with the respective frame members  3  wherein the top or horizontal flange element of the grid flange  11  is positioned on top of the frame members  3  and the side or vertical flange element is positioned against the side of the frame members  3 , respectively. Fasteners such as nails  15  ( FIG. 1 ) can then be quickly and easily extended through the respective top openings  11   a  and/or the side openings  11   b  and driven into the wooden frame members  3 , without the need for clips, retainers or brackets which are commonly used to install fill hangers on an assembly frame in conventional cooling tower installations. 
   Referring next to  FIGS. 1-4  of the drawings, the fill hangers  6  are each further characterized by a hanger grid  7 , defined in a preferred embodiment by horizontal grid members  8  and vertical grid members  9  of selected cross-sectional configuration. The horizontal grid members  8  and vertical grid members  9  further define hanger grid openings  10  of a selected size or sizes determined by the spacing of the horizontal grid members  8  and the vertical grid members  9 . In this embodiment of the invention each of the horizontal grid members  8  has spaced-apart anchor rivet pins  12  extending upwardly therefrom into a corresponding hanger grid opening  10  in disproportionate or off-center relationship with respect to the two adjacent vertical grid members  9 , as illustrated in  FIGS. 1 ,  3  and  4 . Each of the anchor rivet pins  12  typically includes a pin base  13 , extending from attachment to or shaped integrally with a corresponding horizontal grid member  8 , and a wedge-shaped, flared tip  14  terminating the pin base  13 . The flared tips  14  of the anchor rivet pins  12  are each sized to fit through the fill grid openings  18  in a corresponding elliptical fill grid  17  of a length of splash fill  16  ( FIG. 2 ), which has a cross-section shaped generally in the configuration of an ellipse. A typical splash fill  16  for application in the fill support grid assembly of this embodiment of the invention is the Opti-Bar (trademark) marketed by Tower Components Incorporated. As in the case of the fill hanger  6 , the fill grids  17  of the splash fills  16  are typically constructed of a plastic material such as high density polyethylene, nylon or the like and the curved fill grids  17  are each characterized by fill grid openings  18  that are slightly smaller than the flared tip  14  of each anchor rivet pin  12  carried by the respective horizontal grid members  8  in the hanger grid  7  of the fill hangers  6 . 
   Referring now to  FIGS. 1 and 3  of the drawings, according to the method of this embodiment of the invention each fill grid  17  is inserted in a parallel assembly or set of fill hangers  6  ( FIG. 1 ), typically through the wider of the two spaces in the registering hanger grid openings  10  on corresponding horizontal grid members  8 , between the respective anchor rivet pins  12  and the adjacent vertical members  9 . The elliptical fill grids  17  are so inserted with the long or major axis of the ellipse in vertical orientation ( FIG. 3 ) to clear the respective anchor rivet pins  12 . When each elliptical fill grid  17  is fully inserted in the corresponding aligned hanger grid openings  10  in the respective hanger grids  7  of the parallel fill hangers  6 , the fill grids  17  are rotated ninety degrees in the direction of the arrow in  FIG. 3 , such that each fill grid  17  is oriented with the long or major axis of the ellipse in the horizontal position and the ends of the fill grids  17  typically snugly engaging the adjacent, parallel vertical grid members  9 . In the course of this 90-degree rotation of the fill grids  17 , the flared tip  14  of each of the anchor rivet pins  12  projects through an aligned one of the fill grid openings  18  in the corresponding fill grid  17  in a friction fit, such that the elliptical fill grids  17  are removably anchored in the respective hanger grid openings  10  of the fill hangers  6 . By “friction fit” is meant an initially spreading by flexure of the fill grid members in the fill grids  17  defining the fill grid openings  18 , to allow passage of the flared tips  14  of the respective anchor rivet pins  12 , and then narrowing of the respective fill grid openings  18  by operation of the memory in the fill grid members, to trap the flared tip  14  inside the corresponding fill grid  17  and secure the fill grids  17  in position in the respective fill hangers  6  ( FIGS. 1 and 3 ). Alternatively, or in combination with this flexure of the fill grid members in each fill grid  17 , the flared tips  14  may also be designed with sufficient resiliency to initially deform and then spring back to effect the desired security in mounting the fill grids  17  in the fill hangers  6 . 
   Accordingly, it will be appreciated by those skilled in the art that the flared tip  14  element of the anchor rivet pins  12  can be of any desired shape, size and resiliency which is compatible with extension or projection through the aligned fill grid openings  18  of the elliptical fill grids  17  of the splash fills  16 . Furthermore, under circumstances where the fill hangers  6  are injection-molded or otherwise fabricated from a material such as nylon (a preferred material) and plastics such as polyethylene and polypropylene, in non-exclusive particular, the pin base  13  and flared tip  14  elements of the anchor rivet pins  12  can be likewise molded with the hanger grids  7  of the respective fill hangers  6 , according to the knowledge of those skilled in the art. 
   Referring now to  FIG. 5  of the drawings, in another embodiment of the invention a segment of the fill support grid assembly  1  is illustrated by a pair of fill hangers  6  having hanger grids  7  which are secured to each other in stacked relationship, wherein the top fill hanger  6  is attached to the bottom fill hanger  6  at a grid flange  11 . This grid flange  11  on the bottom fill hanger  6  includes multiple, spaced-apart flange notches  19  which receive the bottom ends of the corresponding vertical grid members  9  of the top fill hanger  6 , as illustrated in  FIG. 5 . Accordingly, the respective hanger grids  7  of the top and bottom fill hangers  6  are typically assembled as illustrated in  FIG. 5 , wherein nails  15  can be driven into the corresponding side openings  11   b  and secured to the frame members  3  as indicated in the drawings, to assemble the respective fill hangers  6 . Under circumstances where multiple fill hangers  6  are stacked as illustrated in  FIG. 5  and no frame members  3  are needed at the interfaces, the bottom ends of the top hanger grid  7  can be secured to the grid flange  11  of the bottom hanger grid  7  using wire or plastic ties, as desired. 
   In another preferred embodiment of the invention and referring again to  FIG. 5 , the anchor rivet pins  12  are configured somewhat differently from those illustrated in the first embodiment of the invention illustrated in  FIGS. 1-4 . In this latter embodiment each of the anchor rivet pins  12  are characterized by an upward-standing pin base  13  attached to a corresponding horizontal grid member  8  as indicated in  FIGS. 1-4  of the drawings. However, the flared tip  14  extending from each of the pin base bases  13  is cone-shaped to engage the fill grid openings  18  in the respective fill grids  17  and secure the fill grids  17  in the corresponding hanger grid openings  10 , as illustrated in  FIGS. 1-4  and heretofore described. 
   Referring to  FIGS. 6 and 7  of the drawings, in yet another preferred embodiment of the invention, each of the vertical grid members  9  is fitted with oppositely-disposed grid nibs  26  ( FIG. 6 ) and grid notches  25  ( FIG. 7 ) above the connecting horizontal grid members  8 , for receiving the plate slots  24  provided in corresponding longitudinal edges of the plate  21  of a “gull wing” fill grid  20 , having a central longitudinal plate ridge  22  and fitted with plate openings  23 . The gull wing fill grid  20  is detailed in U.S. Pat. No. 4,576,764 and is installed as a splash fill  16  in the respective hanger grids  7  of the fill hangers  6  of this invention. The gull wing fill grid  20  is typically fitted with the longitudinally spaced-apart plate slots  24  which may be quickly and easily seated in the respective hanger grid openings  10  of the hanger grids  7 , between the corresponding vertical grid members  9 , in the following manner. Each of the plates  21  of the respective gull wing fill grids  20  is typically grasped at one end, with the fingers and thumb positioned across the expanse or width of the plate  21  and the plate  21  is then bent or deformed longitudinally along the plate ridge  22 , into the position illustrated in the left-hand portion of  FIGS. 6 and 7 . Each plate  21  is then inserted in this bent configuration, into registering hanger grid openings  10  in the parallel hanger grids  7  of the fill hangers  6  to align the respective plate slots  24  with the grid nibs  26  ( FIG. 6 ) and the grid notches  25  ( FIG. 7 ), provided in the corresponding, oppositely-disposed vertical grid members  9  in the fill hangers  6 . Each plate  21  is then released, allowing the plate  21  to assume its original position by memory, as illustrated in the right hand portion of  FIGS. 6 and 7  and fully engage the respective plate slots  24  of the plates  21  with the corresponding grid nibs  26  ( FIG. 6 ) and grid notches  25  ( FIG. 7 ). In this manner, the respective plates  21  of the gull wing fill grid  20  are removably, yet securely installed in the hanger grids  7  of the fill hangers  6  in longitudinal, edge-to-edge configuration, as illustrated in  FIGS. 6 and 7 . 
   It will be appreciated that the fill support grid assembly  1  in all embodiments of this invention can be installed on new cooling towers or retrofitted to existing cooling towers characterized by both counter-flow and cross-flow application, as well as in other mass and heat transfer equipment applications requiring liquid-gas, extended surface, interphase contact conditions. Accordingly, the fill support grid assembly  1  can be used in such applications as trickle filters, absorption towers, air washer cells, stripping units and heat recovery economizer units, in non-exclusive particular, in addition to the cooling tower application set forth herein. Moreover, both of the hanger grid  7  designs which accommodate the elliptical fill grids  17  and gull wing fill grids  20  can be used in a single installation, if so desired. 
   Referring again to  FIGS. 1 and 5  of the drawings, when the hanger grids  7  of the respective fill hangers  6  are to be installed on the frame members  3  of the assembly frame  2 , each hanger grid  7  is typically grasped by one hand and the grid flange  11  seated on the appropriate frame member  3 , with the horizontal element of the grid flange  11  extending over the top of the frame member  3  and the vertical element thereof fitted tightly against the side of the frame member  3 . A hammer is then typically grasped by the other hand and the nails  15 , typically magnetically seated on the hammer, are driven sequentially through one of the top openings  11   a  or the side openings  11   b  to fasten the fill hangers  6  to the frame member  3  of the assembly frame  2 . This design facilitates mounting the respective fill hangers  6  on the corresponding frame members  3  of the assembly frame  2  by one person, thus cutting labor costs as well as saving time. Additional nails  15  can then be driven through the remaining top openings  11   a  ( FIG. 1 ) and side openings  11   b  into the frame members  3  to complete the fill hanger installation. Under circumstances where the stacked fill hanger design illustrated in  FIG. 5  is utilized, the respective fill hangers  6  can be suspended from the frame members  3  as illustrated and then mounted in a stacked arrangement by securing the respective slotted grid flanges of the hanger grid; on the frame members  3  at selected increments. At those slotted grid flange  11  interfaces where no frame members  3  are installed, the two stacked fill hangers  6  can be connected by metal or plastic ties. 
   A primary advantage of using the preferred nylon hanger grids  7  in the fill support grid assembly  1  of this invention is the facility for shipping these components without fear of nicking or bending damage, as is the case with respect to stainless steel and polyvinyl chloride (PVC)-coated wire fill hangers. Moreover, the hanger grids  7  are so designed that the gull wing fill grids  20 , as well as the elliptically-shaped splash fills  16  used in the fill support grid assembly  1  of this invention are easily inserted in the respective hanger grid openings  10  highly efficient in eliminating the undesirable streaming and channeling of water which is so prevalent in other splash fill designs. 
   While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.