Patent Description:
The performance of a cooling tower can be characterized by the quantity of water or other cooling fluid that can be cooled to a specified operating temperature for a certain set of ambient conditions. In order to achieve this cooling, water is sprayed onto the cooling tower fill and is exposed to an air flow, thereby causing evaporation of a small portion of water into the air, which cools the remaining water. By increasing the amount of evaporation occurring within the cooling tower, the overall performance of the tower may also be increased or improved. Since most of this evaporation occurs within the fill, changes to the fill design can significantly impact the amount of cooling a tower can achieve during operation. Specifically, changes to a cooling tower fill that reduce the pressure drop across a fill for a given air flow or otherwise improve the thermal performance of the fill, will result in a better performing cooling tower. By reducing the pressure drop across a fill, the resistance to airflow through the tower is decreased, allowing more air to pass over the water film for the same fan power, thereby causing the amount of evaporation to increase. To improve the thermal performance of a fill, increased mixing of the air and water can increase the amount of evaporation of water into the air by improving the conditions at the air-water interface. Generating mixing of the air, however, typically requires changes to the fill which also increases the pressure drop across the fill, indicating the need for fill designs which can either reduce pressure drop over existing designs with minimal impact to mixing or improved strategies for mixing which require equal or less pressure drop.

For cross-flow cooling towers, film fills are installed in the tower as a hanging fill, or as a bottom supported fill. For hanging fills, holes are punched near the top of the fill sheets to accept rails or for mounting on rails where the fill sheets are spaced along the length of the rails. This causes the individual fill sheets to be under tensile loading under the holes, but under compressive loading at the rail-sheet interface. For bottom supported fills, sheets are secured together into rigid blocks of fill, then placed on top of a support structure in the tower. Typically, bottom supported fills are easier to install into towers than hanging fills but the bottom supported fill sheets require additional structural features to resist the compressive loading seen during use, particularly during operation under loading from the water or other cooling fluid utilized in the tower or from the accumulation of external deposits, such as ice, biological foulants, scale or related other accumulated deposits that all apply additional weight and forces onto the fill. These structural features of the fill sheets, such as structural ribs or glue boss features, usually provide little to no thermal benefit for the fill and increase the pressure drop, thereby resulting in reduced tower performance. Alternative to the structural ribs and glue bosses, thicker gauge sheets may be used for the fill construction, however the increase in gauge thickness increases the total cost of the fill by adding more material to each fill sheet.

For film fills used in cross-flow towers, all fills contain a dedicated heat transfer area, while some also contain an integral drift eliminator near the air outlet of the fill and/or a louver section near the air inlet of the fill. The heat transfer area of the fill is responsible for the thermal performance of the fill by providing a large surface area for water to spread out on the surfaces of the fill to increase contact with the air, mixing the air as it flows through the fill and mixing the water film as it flows over the sheets, while maintaining a low pressure drop across the fill. Typically, the heat transfer surface for cross-flow fills consists of fluted fill sheets with small surface features (microstructure) patterned across the surface or fill sheets with more aggressive patterned features and less pronounced flute features. For fills with flutes, the flutes are usually continuous across the heat transfer area or have a generally constant cross-section along their length and are commonly cross corrugated, although may be oriented horizontally or vertically.

Although most of the bulk water adheres to the surface of a film fill, some of the water forms small droplets and escapes the fill through the air outlet, otherwise known as drift. Drift is undesirable, as the drift represents a loss of water or other cooling fluid from the system and the loss of water or other cooling fluid has a cost to replenish, both itself and any treatment chemicals contained within the cooling fluid. The drift may also have a deleterious impact on surrounding equipment and environments since the drift may contain chemicals, salts and bacteria present in the circulating water or fluid. For cross-flow tower film fills, drift elimination features are sometimes included on the air outlet side of the sheet to capture these drift droplets and prevent them from escaping the cooling tower, which are referred to as drift eliminators and may be comprised of integral drift eliminators ("IDs"). For cross-flow film fills, there are typically two different types of drift eliminators which may be integrated, including the tube drift eliminator and the blade drift eliminator. Generally, tube drift eliminators are angled tubes formed into the ID section of the fill by aligning drift corrugations of adjacent sheets. As water droplets enter the tubes entrained in the air stream, the momentum of the droplets causes them to impact the tube wall as the airflow changes direction while following the angled tube of the ID. A vertical channel is typically included at the inlet of the integral drift eliminator tubes to allow water collected on the surface of the integral drift eliminator to drain out of the fill into a lower catch basin, and to provide vertical structural support for bottom supported fills. One limitation of current implementations of this type of drift eliminator is introduced when water reaches the tube inlet of the eliminator. When water reaches the transition between the tube section and the drain, some water may be pushed along part of the top wall of the tube by the air before falling off into the air stream. By introducing droplets farther into the eliminator, it becomes easier for these droplets to escape out of the eliminator without impacting a wall, thereby reducing eliminator performance. Integral blade drift eliminator designs accomplish drift removal by creating a large vertically oriented ridge, near the air outlet of the fill to change the direction of airflow. The momentum of the water droplets at the integral drift eliminator inlet causes an impact with the ridge walls, eliminating the drift from the airstream. Other structural features such as ribs or spacers may be included before or after the eliminator ridge to ensure the sheets remain separated during operation and to stiffen the fill and/or sheet, as well as the assembled fill pack.

At the air inlet of the fill, integral louvers are sometimes included into the fill design to prevent water from splashing out of the front of the fill. These integral louvers are usually comprised of corrugations which are angled downward as they protrude into the fill, to provide a sloped surface for the water to run down, thereby preventing water or other cooling fluid from reaching the front of the fill. The corrugations on each sheet may be assembled together to form tubes or remain parallel to adjacent sheet corrugations with additional sheet spacer features added to the design.

<CIT> may disclose a fill pack suitable for cooling heat transfer fluid in a cooling chamber, where a drift caused by the contact of the column packing constituting elements with the inner wall of the device can be eliminated by having a drift eliminator located at the air outlet side. The drift eliminator of <CIT> may comprise ribs defined by adjacent ones of flutes and curving upwards toward the flute outlet.

The invention is directed to a fill pack for cooling heat transfer fluid in a cooling tower with the features of claim <NUM>. The fill pack includes a first fill sheet having a first air intake side, a first top edge, a first air outlet side and a first heat transfer area between the first air intake side and the first air outlet side and a second fill sheet having a second air intake side, a second top edge, a second air outlet side and a second heat transfer area between the second air intake side and the second air outlet side. An integral drift eliminator is associated with the first and second air outlet sides in an installed configuration. The drift eliminator defines a plurality of tubes with a drift eliminator inlet positioned proximate the first and second heat transfer areas and a drift eliminator outlet spaced away from the first and second heat transfer areas. The plurality of tubes extends generally toward the first and second top edges from the drift eliminator inlet toward the drift eliminator outlet. Each of the plurality of tubes includes a blocking structure at the drift eliminator inlet configured to block heat transfer fluid at the drift eliminator inlet to promote droplet formation and capture of the heat transfer fluid in the drift eliminator.

The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:.

Certain terminology is used in the following description for convenience only and is not limiting. Unless specifically set forth herein, the terms "a", "an" and "the" are not limited to one element but instead should be read as meaning "at least one". The words "right," "left," "lower," and "upper" designate directions in the drawings to which reference is made. The words "inwardly" or "distally" "front" or "rear" and "outwardly" or "proximally" refer to directions toward and away from, respectively, the geometric center or orientation of the fill sheets or fill packs and related parts thereof. The terminology includes the above-listed words, derivatives thereof and words of similar import.

It should also be understood that the terms "about," "approximately," "generally," "substantially" and like terms, used herein when referring to a dimension or characteristic of a component of the invention, indicate that the described dimension/characteristic is not a strict boundary or parameter and does not exclude minor variations therefrom that are functionally the same or similar, as would be understood by one having ordinary skill in the art. At a minimum, such references that include a numerical parameter would include variations that, using mathematical and industrial principles accepted in the art (e.g., rounding, measurement or other systematic errors, manufacturing tolerances, etc.), would not vary the least significant digit.

Referring to <FIG>, a fill sheet, generally designated <NUM>, in accordance with a first preferred embodiment of the present invention has a heat transfer section <NUM>, along with an air inlet portion <NUM>, which may include an integral louver (not shown), an air outlet portion <NUM>, which may include an integral drift (See <FIG>), and/or other standard end features at the inlet portion <NUM> and/or the outlet portion <NUM>, as well as additional features, such as intermediate honeycombs. The fill sheet <NUM> is not limited to including the integral louver or the integral drift, neither of which are shown in the first preferred embodiment of the fill sheet <NUM>, and may function without the louver and drift or may include alternative features attached to, integrally formed with, positioned adjacent to or abutting the air inlet and outlet portions <NUM>, <NUM>, such as non-integral louvers and drift that abut, but are not integrally formed with the fill sheet <NUM>. The air inlet portion <NUM> of the first preferred fill sheet <NUM>, which may include an integral louver, is positioned at the air intake side 10a of the sheet <NUM> and the air outlet portion <NUM>, which may include an integral drift, is positioned at the air outlet side 10b of the preferred cross-flow fill sheet <NUM>.

The heat transfer section <NUM> of the first preferred fill sheet <NUM> includes a herringbone-shaped microstructure 11a or the microstructure 11a has a generally herringbone shape to increase the surface area of the fill sheet <NUM> in the heat transfer section <NUM> and provide mixing of the air and water during operation. The microstructure 11a is not limited to being comprised of the herringbone-shaped microstructure and may be comprised of alternatively sized and shaped microstructure that increases the surface area of the fill sheet <NUM> in the heat transfer section <NUM> to expose additional water film area to the airflow. The microstructure 11a preferably has a smaller microstructure height Hs when compared to the height of the macrostructure of the preferred fill sheet <NUM>, wherein the macrostructure includes features such as the plurality of flutes <NUM>, as is described in greater detail below. In the preferred embodiments, the microstructure height Hs is <NUM> to <NUM> (three hundredths of an inch to one-half inch (<NUM> - <NUM>")) but is not so limited and may fall outside this range depending on designer preferences, microstructure type, cooling tower type, expected loading and related design considerations and preferences. The microstructure height Hs, however, of the preferred microstructure 11a is within the preferred range of the microstructure height Hs and is adaptable for use with the preferred fill sheets <NUM>.

The heat transfer section <NUM> of the fill sheet <NUM> also includes a spacer <NUM>, which may be comprised of pluralities of spacers <NUM>. The spacers <NUM> may be comprised of glue bosses, peg spacers or other similar structures or features that space the fill sheets <NUM>, 9a, 9b from each other in the assembled or installed configurations. The spacers <NUM> preferably extend from opposing front and rear surfaces of the fill sheet <NUM> and mate with opposing spacers <NUM> on adjacent fill sheets <NUM>, but are not so limited and may be configured to extend from only a single surface of the fill sheet <NUM> or may be otherwise sized and configured to space the fill sheets <NUM> in the assembled configurations. The spacers <NUM> on the adjacent fill sheets <NUM> in an assembled configuration are also preferably comprised of mating glue bosses or peg spacers that facilitate spacing of the assembled fill sheets <NUM> relative to each other. The spacers <NUM> are not limited to mating glue bosses or peg spacers and may be comprised of nearly any feature of the fill sheets <NUM> that facilitates spacing of the adjacent fill sheets <NUM> relative to each other in the assembled configuration, including suspension or hanging of the fill sheets <NUM> next to each other at predetermined spacing intervals or distances during operation. The spacers <NUM> may assist in joining or bonding the adjacent fill sheets <NUM> together in the assembled configuration or may provide general spacing between the adjacent fill sheets <NUM> in the assembled configuration. The configuration and operation of the spacers <NUM> are described in greater detail below. The fill sheets <NUM> of the preferred embodiments may also include spacers <NUM> with alignment or connection features <NUM> extending therefrom. The spacers <NUM> preferably provide a surface for mating with a spacer <NUM> from an adjacent fill sheet <NUM> to appropriately space a first fill sheet 9a from a second fill sheet 9b in the assembled or installed configuration. The alignment or connection features <NUM> preferably facilitate proper alignment of the first sheet 9a relative to the second sheet 9b and/or provide for engagement or connection of the adjacent fill sheets <NUM> in the assembled or installed configuration.

The heat transfer section <NUM> of the fill sheet <NUM> further includes flutes <NUM> arranged thereon that generally extend parallel or substantially parallel to a lateral axis <NUM> of the fill sheet <NUM>. The lateral axis <NUM> extends generally horizontally in an installed configuration of the fill sheets <NUM> and is oriented generally perpendicular to a vertical axis <NUM>. The flutes <NUM> preferably guide the airflow through the heat transfer area <NUM>, generally along the lateral axis <NUM> from the intake side 10a to the outlet side 10b.

The first preferred fill sheet <NUM> also includes an improved rib configuration for vertical and lateral rigidity and strength of the fill packs in the assembled configuration, including intake side ribs <NUM> and outlet side ribs <NUM> that extend generally parallel to the air intake side 10a and air outlet side 10b, respectively. The intake side ribs <NUM> and the outlet side ribs <NUM> are preferably integrally formed in the fill sheet <NUM> proximate the air intake side 10a and the air outlet side 10b, respectively and adjacent to the heat transfer area <NUM> or within the heat transfer area <NUM>. The intake side ribs <NUM> and the outlet side ribs <NUM> are described in greater detail below.

Referring to <FIG>, in a second preferred embodiment, a fill sheet <NUM>' has similar features to the first preferred fill sheet <NUM> and the same reference numerals are utilized to identify similar or the same features, with a prime symbol (') utilized to distinguish the features of the second preferred embodiment from the first preferred emboidment. The second preferred fill sheet <NUM>' includes an integral drift eliminator <NUM> that improves upon known tube based integral drift eliminators (not shown) by introducing a blocking structure <NUM> to improve drift performance, as is described greater detail below.

Referring to <FIG> and <FIG>, in the first and second preferred embodiments, the fill sheets <NUM>, <NUM>' are oriented in the cooling tower and configured at a forward lean or to have a pack angle Δ, Δ' of approximately five to ten (<NUM>-<NUM>) degrees in order to offset the effects of the crossing airflow on the vertically flowing water on the fill sheet surfaces during operation. As the water flows down the sheets <NUM>, <NUM>', generally parallel to the vertical axis <NUM>, <NUM>', the air tends to push the water toward the air outlet side 10b, 10b' of the fill sheets <NUM>, <NUM>' due to friction at the air-water interface. The fill sheets <NUM>, <NUM>', thereby lean into the direction of air flow, generally along the lateral axis <NUM>, <NUM>' such that a top front corner of the fill sheets <NUM>, <NUM>' near the intersection of the air intake side 10a, 10a' and a top edge <NUM>, <NUM>' is positioned closest to the air inlet of the tower. The lower front corner of the fill sheets <NUM>, <NUM>' near the intersection of the air intake side 10a, 10a' and a bottom edge <NUM>, <NUM>' is the portion of the air intake side that is positioned furthest from the air inlet of the tower.

Referring to <FIG>, the heat transfer area <NUM> of the fill sheet <NUM> is comprised of the herringbone-shaped microstructure 11a formed over the flutes <NUM> and covers a majority of the interior of the fill sheet <NUM>. The geometry of the flutes <NUM> is generally comprised of individual flutes <NUM> oriented substantially in the air travel direction or generally parallel to the lateral axis <NUM>. The fill sheets <NUM> also preferably include transition features <NUM>, which may be comprised of offsets <NUM> in the flutes <NUM>. The transition features <NUM> preferably provide a generally flat macrostructure extending generally parallel to the vertical axis <NUM> or pitched by the pack angle Δ, Δ' from the vertical axis <NUM>. A first flute <NUM> of the plurality of flutes <NUM> transitions from the flat section of the transition feature <NUM> to the arcuate macrostructure spaced from the transition feature <NUM> (See <FIG>). The flat section preferably includes a rib or support <NUM> extending generally parallel to the vertical axis <NUM> and a spacer <NUM> to provide lateral support for the rib or support <NUM>. The spacer <NUM> is preferably positioned proximate the rib or support <NUM> to provide lateral support for the rib or support <NUM> and is not limited to being positioned in the flat section or transition feature <NUM> but is preferably positioned proximate the rib or support <NUM> to provide lateral support. The spacer <NUM> is preferably comprised of a first plurality of spacers <NUM> along or at the offset <NUM>, wherein each of the plurality of flutes <NUM> is associated with or includes one of the first plurality of spacers <NUM> positioned thereon at the offset, flat section or transition feature <NUM>. The pluralities of spacers <NUM> of the first preferred fill sheet <NUM> are positioned at each of the offsets <NUM> proximate the air intake side10a, proximate the air outlet side 10b, and proximate the intermediate vertical ribs <NUM>, respectively.

The preferred fill sheets <NUM> include several intermediate offsets <NUM> in the flutes <NUM> where the peaks <NUM> of the flutes <NUM> transition to valleys <NUM>, and vice versa, generally along the air flow direction or the lateral axis <NUM>. The offsets or transition features <NUM> are typically positioned proximate to the columns of spacers <NUM> such that two adjacent fill sheets <NUM>, such as the first and second fill sheets 9a, 9b (<FIG>) may be connected together or positioned next to each other to define a fill pack <NUM>. The first preferred fill sheets <NUM> and the fill pack <NUM> of <FIG> and <FIG> show the transition of the peaks <NUM> to the valleys <NUM> and the valleys <NUM> to the peaks <NUM> on opposite sides of the offsets or transition features <NUM> in the direction of the lateral axis <NUM>, thereby creating a generally parallel orientation of the adjacent first and second fill sheets 9a, 9b in the heat transfer area <NUM>. The position of the offsets <NUM> in the air travel direction or generally parallel to the lateral axis <NUM> is staggered between the adjacent first and second fill sheets 9a, 9b for any given vertical position on the fill pack <NUM>. By staggering the offsets <NUM>, a majority of the profiles of the flutes <NUM> for the fill pack <NUM> is parallel (<FIG> and 3D) to the adjacent first and second sheets 9a, 9b, while short segments of the fill pack <NUM> between sets of offsets <NUM> have an opposing profile or adjacent peaks <NUM> to valleys <NUM> in the offsets <NUM> of the adjacent sheets 9a, 9b (<FIG>), thereby providing a location for spacers <NUM> to be incorporated into the design without significantly protruding into the airstream of the flutes <NUM> and contributing to pressure drop. This first preferred configuration of the flutes <NUM> provides an advantage over prior tube-based flute arrangements by allowing the majority of the profiles of the flutes <NUM> of the fill pack <NUM> to remain generally parallel to and between the adjacent sheets 9a, 9b, thereby reducing areas of restricted air flow between the peaks <NUM> and valleys <NUM> of adjacent sheets 9a, 9b of the fill pack <NUM>. The staggered offsets <NUM> also create a short tube region within the fill pack <NUM>, which offers structural advantages over a flute design that only consists of parallel flute profiles. By providing short segments proximate the offsets <NUM> where the flutes <NUM> are aligned into a tube configuration with the peaks <NUM> and valleys <NUM> of the adjacent sheets 9a, 9b generally aligning in the offsets <NUM>, the lateral stiffness of the fill pack <NUM> is increased, without the need for large spacer features intruding into the airflow region. In addition, the transition regions on either side of the tube structure of the offsets <NUM> provide a generally flat section to add vertical ribs or supports, such as intermediate vertical ribs or supports <NUM> without cutting through the profile of the flutes <NUM>. The intermediate vertical ribs or supports <NUM> strengthen the fill pack <NUM> without significantly increasing the pressure drop across the fill pack <NUM> between the air intake side 10a and the air outlet side 10b.

Referring to <FIG> and <FIG>, in addition to the improved geometry of the flutes <NUM> in the fill pack <NUM> of the first preferred embodiments used in the cross-flow fill design, improvements have been made to the spacers <NUM> used to space the adjacent fill sheets 9a, 9b apart to define the fill packs <NUM>. The first preferred embodiment of the spacers <NUM> has a generally angled teardrop or raindrop shaped spacer <NUM>, at least in the heat transfer area <NUM> where the microstructure 11a is formed on the fill sheets <NUM>. In an installed configuration, a first spacer 16a of the first fill sheet 9a mates with and is joined, positioned in facing engagement or positioned proximate to a second spacer 16b on the second, adjacent fill sheet 9b to space the first and second fill sheets 9a, 9b at a predetermined distance from each other and may facilitate joining or connection of the adjacent fill sheets 9a, 9b. The preferred fill sheets 9a, 9b have a plurality of spacers <NUM> that extend from both opposing faces of the fill sheets 9a, 9b to mate with adjacent fill sheets 9a, 9b, <NUM> in the installed configuration. As a non-limiting example, the first preferred fill sheets 9a, 9b, <NUM> have three columns of fourteen (<NUM>) spacers <NUM> proximate a middle of the fill sheets 9a, 9b, <NUM> along the offsets <NUM> and the air intake and air outlet sides 10a, 10b, respectively. The fill sheets 9a, 9b also include pluralities of spacers <NUM> positioned adjacent the air intake and air outlet sides 10a, 10b with the alignment or connection features <NUM> thereon. The three columns of spacers <NUM> include an intermediate column of spacers 15b, an air intake side column of spacers 15a and an air exit side column of spacers 15c. In the first preferred embodiment, the air intake side column of spacers 15a is positioned at an air intake side offset <NUM>, the intermediate column of spacers 15b is positioned at an intermediate offset <NUM> and the air exit side column of spacers 15c is positioned at an air exit side offset <NUM>. The intermediate column of spacers 15b is positioned between a first intermediate rib 38a and a second intermediate rib 38b at the intermediate offset <NUM>. The first intermediate rib 38a is positioned between the intermediate column of spacers 15b and the air intake side 10a and the second intermediate rib 38b is positioned between the intermediate column of spacers 15b and the air exit side 10b. The fill sheets 9a, 9b, <NUM> are not limited to including the fourteen (<NUM>) spacers <NUM> in each of the columns of spacers 15a, 15b, 15c or to the specific locations shown in the preferred embodiments and may include more or less spacers <NUM>, depending on the size of the fill sheets 9a, 9b, <NUM>, the expected loading on the fill sheets 9a, 9b, <NUM>, the expected environment, designer preferences and related factors. The fill sheets 9a, 9b, <NUM> may include nearly any number of spacers <NUM> that facilitate spacing or joining of the adjacent sheets 9a, 9b, <NUM> together in the installed configuration, are able to withstand the normal operating conditions of the spacers <NUM> and perform the functions of the spacers <NUM>, as described herein.

In the first preferred embodiment, each of the spacers <NUM> includes a generally wider and relatively semi-circular shaped head end <NUM> and a narrower tail end <NUM>. The first spacer 16a includes a first head end 40a and a first tail end 42a and the second spacer 16b includes a second head end 40b and a second tail end 42b. The head ends <NUM> and the tail ends <NUM> define the teardrop or raindrop shape of the spacer <NUM>, wherein the tail ends <NUM>, 42a, 42b are generally rounded, particularly in comparison to a traditional teardrop or raindrop shape. In the installed configuration, the head ends <NUM> of adjacent spacers <NUM> generally mate and provide surfaces for joining the spacers <NUM> and the tail ends <NUM> extend away from each other in the installed configuration, generally to opposite sides of the vertical axis <NUM>. The tail ends <NUM> of the first preferred embodiment extend away from the head ends <NUM> along a spacer axis <NUM>. In the first preferred embodiment, the first spacer 16a includes a first spacer axis 17a and the second spacer 16b includes a second spacer axis 17b. The first and second spacer axes 17a, 17b preferably define first and second acute spacer angles Ωa, Ωb, respectively, with the lateral axis <NUM> that are approximately ten to eighty degrees (<NUM>-<NUM>°), but are not so limited and may take on nearly any acute angle that facilitates performance of the functioning of the spacers <NUM> and withstands the normal operating conditions of the spacers <NUM>, such as within the range of approximately twenty to fifty degrees (<NUM>-<NUM>°) or approximately thirty-five degrees (<NUM>°). The first spacer axis 17a preferably extends at a first side of the vertical axis <NUM> and the second spacer axis 17b preferably extends at a second, opposite side of the vertical axis <NUM>, such that the first and second spacer axes 17a, 17b extend at opposite sides of the vertical axis <NUM>. This extension of the first and second spacer axes 17a, 17b at opposite sides of the vertical axis <NUM> results in the first and second tail ends 42a, 42b being spaced from each other in an installed configuration such that cooling fluid generally does not collect at and bridge between the first and second tail ends 42a, 42b, particularly if they were to substantially mate. The first spacer axis 17a preferably extends from a central portion of the first head end 40a through a central portion of the first tail end 42a and the second spacer axis 17b preferably extends from a central portion of the second head end 40b through a central portion of the second tail end 42b, even if the first and second spacers 16a, 16b have some curvature to the tail ends 42a, 42b and is not necessarily straight or uniformly shaped. The first and second spacer axes 17a, 17b also preferably define a separation angle µ measured between the first and second acute spacer angles Ωa, Ωb across the vertical axis <NUM>. The separation angle µ is preferably between approximately twenty and one hundred sixty degrees (<NUM>-<NUM>°), preferably approximately one hundred twenty degrees (<NUM>°). The separation angle µ plus the first and second spacer angles Ωa, Ωb preferably sum to one hundred eighty degrees (<NUM>°).

In the first preferred embodiment, adjacent spacers <NUM>, such as the first and second spacers 16a, 16b, are oriented with their tail ends 42a, 42b extending in opposite directions or to opposite sides of the vertical axis <NUM>, thereby forming an upside down V-shape when viewed from the front or rear (<FIG> and <FIG>). This mis-alignment of the tail ends <NUM>, 42a, 42b allows water, which hits the head ends <NUM>, 40a 40b of the pair of spacers <NUM>, 16a, 16b, to run down the sloped side surfaces of each of the spacers <NUM>, 16a, 16b and separate near the tail ends <NUM>, 42a, 42b of the spacers <NUM>, 16a, 16b. In contrast, prior art glue bosses that fully align and have generally the same size and shape result in the water or other cooling fluid flowing over the prior art glue bosses and forming a film of water below the connection, which spans between the two associated fill sheets and impedes airflow. The inverted V shape formed by the tail ends <NUM>, 42a, 42b of the adjacent spacers <NUM>, 16a, 16b is the preferred shape to provide a contact surface to space adjacent fill sheets <NUM>, 9a, 9b and to prevent water sheeting, while minimizing the height of the spacer profile between the adjacent fill sheets <NUM>, 9a, 9b of the fill packs <NUM> in the waterflow direction or generally parallel to the vertical axis <NUM>. The preferred spacers <NUM> have the teardrop or raindrop shape, but this shape is not limiting. For example, in an alternative preferred embodiment, the spacers <NUM> may have a generally rectangular shape (<FIG>), or any shape which forms a contact feature with an adjacent spacer feature near the top of the connection, and slopes downward and away from the adjacent spacer <NUM> relative to the vertical axis <NUM>. The adjacent spacers <NUM>, 16a, 16b are preferably glued or otherwise secured together, such as by ultrasonic welding or mechanical joining, at the mating surfaces in the installed configuration to connect the fill sheets <NUM>, 9a, 9b together, thereby forming the fill packs <NUM>. The spacers <NUM>, 16a, 16b are not limited to being glued or otherwise joined together in the installed configuration and may act exclusively as spacers to space the adjacent fill sheets <NUM>, 9a, 9b relative to each other in the installed configuration, such as when the fill sheets <NUM>, 9a, 9b hang from a rail adjacent to each other in the tower, but are not otherwise joined or connected at the spacers <NUM>, 16a, 16b. In addition, the spacers <NUM>, 16a, 16b may include connection features that secure the spacers <NUM>, 16a, 16b together in the installed configuration or may be otherwise connected or joined together in the installed configuration, such as by ultrasonic welding, mechanical deformation, fastening or otherwise securing the mating spacers <NUM>, 16a, 16b together in the installed configuration.

Referring to <FIG>, structural support is provided to the first preferred fill sheets <NUM>, 9a, 9b and fill packs <NUM> by the intake side ribs <NUM>, the outlet side ribs <NUM> and the intermediate vertical ribs or supports <NUM>, as well as the remaining body of the fill sheets <NUM>, 9a, 9b. Each of the intake and outlet side ribs <NUM>, <NUM> and the intermediate ribs <NUM> is preferably comprised of two substantially vertical support ribs 24a, 24b, 26a, 26b, 38a, 38b extending along the height of the fill sheet <NUM>, 9a, 9b, generally parallel to the air intake side 10a and the air outlet side 10b. In the first preferred embodiment, the support ribs 24a, 24b, 26a, 26b, 38a, 38b are not fully vertical, but are oriented substantially parallel to the air intake and air outlet sides 10a, 10b of the fill sheets 9a, 9b, <NUM>, such that the support ribs 24a, 24b, 26a, 26b, 38a, 38b are oriented generally at the pack angle Δ, Δ' of approximately five to ten (<NUM>-<NUM>) degrees relative to the vertical axis <NUM>, but are not so limited and may be otherwise oriented and configured. The microstructure 11a of the heat transfer area <NUM> of each of the fill sheets <NUM>, 9a, 9b is preferably comprised of angled bands of microstructure 11a in the herringbone arrangement, extending between at least the first structural intake and outlet side ribs 24b, 26a, respectively, in the heat transfer area <NUM>. The preferred support ribs <NUM>, <NUM>, <NUM>, including the intake side ribs <NUM>, 24a, 24b, the outlet side ribs <NUM>, 26a, 26b and the intermediate ribs <NUM>, 38a, 38b, extend generally vertically along the fill sheet <NUM>, 9a, 9b in the installed configuration. The ribs 24a, 24b, 26a, 26b, vary in height in an alternating pattern as they extend along the fill sheet <NUM>, 9a, 9b from and between the top edge <NUM> and the bottom edge <NUM>. In the preferred embodiment, the intake and outlet side ribs 24a, 24b, 26a, 26b alternate between a maximum height Hx and a minimum height Hn. The pairs of first and second intake side ribs 24a, 24b of the intake side rib <NUM>, the first and second outlet side ribs 26a, 26b of the outlet side rib <NUM>, and the first and second intermediate supports 38a, 38b of the intermediate support <NUM> are designed such that there is preferably at least one rib or support 24a, 24b, 26a, 26b, 38a, 38b with a height, such as the rib maximum height Hx extending past or being greater than the microstructure height Hs of the microstructure 11a on any given position along the lengths of the individual ribs or supports <NUM>, <NUM>, <NUM> on the fill sheets <NUM>, 9a, 9b.

In the first preferred embodiment, the first and second air intake ribs 24a, 24b are configured such that while the first air intake rib 24a has the maximum height Hx that extends past or is greater than the microstructure height Hs of the microstructure 11a and the second air intake rib 24b extends below or has the rib minimum height Hn that is less than the microstructure height Hs of the microstructure 11a. Similarly, the first and second outlet side ribs 26a, 26b are configured such that while the first outlet side rib 26a has the rib maximum height Hx that extends past or is greater than the microstructure height Hs of the microstructure 11a, the second outlet side rib 26b has the rib minimum height Hn that dips below or is less than the microstructure height Hs of the microstructure 11a. The first and second intermediate ribs or supports 38a, 38b are similarly configured in the first preferred embodiment in that the first and second intermediate ribs 38a, 38b are laterally spaced, but are differently configured in that the first intermediate rib 38a substantially ends at a height where the second intermediate rib 38b begins. There may be sections where both of the first and second inlet side ribs 24a, 24b, the first and second outlet side ribs 26a, 26b and the first and second intermediate ribs or supports 38a, 38b are taller than the surrounding microstructure 11a to provide additional support at the base of the fill sheets <NUM>, 9a, 9b and fill packs <NUM>, such as where the fill pack <NUM> meets the supporting structure underneath the fill pack <NUM> in an assembled configuration in the tower. The air intake and outlet ribs <NUM>, <NUM> are, however, preferably configured such that when one of the pair of first and second ribs 24a, 24b, 26a, 26b, respectively, is at its greatest height relative to the microstructure 11a, the adjacent one of the pair of first and second ribs 24a, 24b, 26a, 26b, respectively, is at its smallest height or is generally below the height of the microstructure 11a and is substantially embedded in the microstructure 11a. The first and second ribs 24a, 24b, 26a, 26b, therefore, have alternating tapers between the top edge <NUM> and the bottom edge <NUM>.

The intake side rib <NUM> and the outlet side rib <NUM> are not limited to extending from the top edge <NUM> to the bottom edge <NUM>. The intake side rib <NUM> and the outlet side rib <NUM> may extend proximate to the top and bottom edges <NUM>, <NUM> and may include some interruptions along their length, but the intake and outlet side ribs <NUM>, <NUM> preferably extend to the top and bottom edges <NUM>, <NUM> and are comprised of the alternately extending pairs of first and second ribs 24a, 24b, 26a, 26b that alternatively taper relative to each other. The intake and outlet side ribs <NUM>, <NUM> extend to and between the top and bottom edges <NUM>, <NUM> in the preferred embodiments. The intake and outlet side support ribs <NUM>, <NUM> include the pairs of first and a second support ribs 24a, 24b, 26a, 26b. The first and second support ribs 24a, 24b, 26a, 26b are spaced laterally from each other along the lateral axis <NUM> and extend substantially parallel to the vertical axis <NUM> or the intake and outlet sides 10a, 10b. The intake and outlet side ribs <NUM>, <NUM> have a first support rib portion <NUM> having a first support rib length or first support rib portion length Lr1. The first support ribs 24a, 26a include a first rib height and the second support ribs 24b, 26b include a second rib height. The first rib height is less than the microstructure height in the first support rib portion <NUM> and the second rib height is greater than the microstructure height in the first support rib portion <NUM>. The intake and outlet side ribs <NUM>, <NUM> of the first preferred embodiment also have a second support rib portion <NUM> having a second support rib length or second support rib portion length Lr2. The first rib height is greater than the microstructure height in the second support rib portion <NUM> and the second rib height is less than the microstructure height in the second support rib portion <NUM>.

The intermediate rib <NUM> is alternatively constructed such that the first intermediate rib 38a extends from the top edge <NUM> approximately to a middle of the vertical height of the fill sheet <NUM> where the first intermediate rib 38a substantially ends and the second intermediate rib 38b starts and extends to the bottom edge <NUM>. The ribs <NUM>, <NUM>, <NUM> are not limited to having these configurations and may be otherwise designed and configured to provide strength and stiffness to the fill sheet <NUM>, such as switching the general configurations of the air intake and outlet ribs <NUM>, <NUM> and the intermediate ribs <NUM> or configuring each of the ribs <NUM>, <NUM>, <NUM> substantially the same.

By alternating the height or positioning of the pairs of first and second ribs 24a, 24b, 26a, 26b of the inlet side and outlet side ribs <NUM>, <NUM> and the intermediate ribs <NUM> so that the localized height of at least one of the pair of first and second ribs 24a, 24b, 26a, 26b, 38a, 38b is preferably greater, specifically at the maximum height Hx, than the microstructure height Hs of the microstructure 11a for any position along the length of the ribs <NUM>, <NUM>, <NUM> on the fill sheets <NUM>, 9a, 9b, it is ensured that each side of the fill sheet <NUM>, 9a, 9b has at least one functioning stiffening member or rib <NUM>, <NUM>, <NUM> for all vertical positions along the air intake side and the air outlet side 10a, 10b, respectively, as well as in the intermediate area or offset <NUM> between the intake and outlet sides 10a, 10b, thereby limiting weak points or sections where the fill sheets <NUM>, 9a, 9b may buckle. Additionally, the lower peak height sections of the pairs of first and second ribs 24a, 24b, 26a, 26b of the intake and outlet side ribs <NUM>, <NUM>, wherein the maximum height Hx is present, allow the bands of overlapping microstructure 11a to stiffen the fill sheet <NUM>, 9a, 9b in the air travel direction or generally parallel to the lateral axis <NUM> by creating minor corrugations which resist bending moment in the plane perpendicular to the applied force at the intake and outlet side ribs <NUM>, <NUM>. This configuration increases the rigidity of the fill sheets <NUM>, 9a, 9b for handling and shipping. The configuration of the intake and outlet side ribs <NUM>, <NUM> and the intermediate rib <NUM>, wherein the full height rib sections or sections with the maximum rib height Hx overlap before transitioning to the lower height rib sections or sections with the minimum rib height Hn of the first and second ribs 24a, 24b, 26a, 26b, 38a, 38b, respectively, where load is transferred between the pairs of first and second ribs 24a, 24b, 26a, 26b, 38a, 38b of the intake and outlet side ribs <NUM>, <NUM> and the intermediate ribs <NUM> strengthens and also adds support at the intake and outlet sides 10a, 10b and the intermediate portion of the fill sheets <NUM>, 9a, 9b.

In the preferred embodiments, the maximum rib height Hx is approximately <NUM> to <NUM> (four hundredths of an inch to three-quarters of an inch (<NUM> - <NUM>")) or approximately <NUM> to <NUM> (one hundredth of an inch to one-quarter of an inch (<NUM> - <NUM>")) greater than the microstructure height Hs. The maximum rib height Hx of the stiffening members or ribs <NUM>, <NUM>, <NUM> is not limited to these particular heights and may be otherwise sized and configured based on the expected loading of the stiffening member ribs <NUM>, <NUM>, <NUM>, external loading factors, designer preferences, size of the fill sheet <NUM>, type of cooling medium employed and other design considerations. The maximum height Hx of the support ribs <NUM>, <NUM>, <NUM>, however, preferably falls within the preferred range such that the maximum height Hx is greater than the microstructure height Hs in desired sections or segments while the minimum rib height Hn is less than the microstructure height Hs and the maximum rib height Hx. In the preferred embodiments, the minimum rib height Hn is approximately <NUM> to <NUM> (zero to one-half inch (<NUM> - <NUM>")) or smaller than the microstructure height Hs of the particular fill sheet <NUM>. The minimum rib height Hn of the stiffening members or ribs <NUM>, <NUM>, <NUM> is not limited to these particular heights and may be otherwise sized and configured based on the expected loading of the stiffening member ribs <NUM>, <NUM>, <NUM>, external loading factors, designer preferences, size of the fill sheet <NUM>, type of cooling medium employed and other design considerations. The minimum rib height Hn preferably falls within the preferred range such that the minimum rib height is less than the microstructure height Hs in desired sections or segments. For example, the minimum rib height Hn is about half or less than half of the microstructure height Hs and the microstructure height Hs is slightly greater than half the maximum rib height Hx in the first preferred embodiment (See <FIG>). The minimum rib height Hn may also be approximately zero, as is shown at the lower portion of the first intermediate rib 38a and the upper portion of the second intermediate rib 38b of the first preferred fill sheet <NUM> (See <FIG>).

In the first preferred embodiment, the first intermediate rib 38a includes a top intermediate rib end 39a and a first intermediate rib end 39b and the second intermediate rib 38b includes a second intermediate rib end 39c and a third intermediate rib end 39d. The first intermediate rib end 39b is positioned proximate the second intermediate rib end 39c on the fill sheets <NUM>, 9a, 9b. The first intermediate rib 38a or the second intermediate rib 38b is intersected by the lateral axis <NUM> between the top intermediate rib end <NUM> and the third intermediate rib end 39d, meaning the first intermediate rib 38a or the second intermediate rib 38b are intersected by the lateral axis <NUM> at generally any location along the height of the fill sheets <NUM>, 9a, 9b between the top intermediate rib end <NUM> and the third intermediate rib end 39d. In the first preferred embodiment, the lateral axis <NUM> preferably intersects the first intermediate rib 38a or the second intermediate rib 38b at any location between the top edge <NUM> and the bottom edge <NUM>, as the first intermediate rib 38a generally extends from the top edge <NUM> to a central portion of the fill sheet <NUM>, 9a, 9b and the second intermediate rib 38b generally extends from the central portion of the fill sheet <NUM>, 9a, 9b, where the first intermediate rib end 39b is positioned proximate the second intermediate rib end 29c, to the bottom edge <NUM>. The first and second intermediate ribs 38a, 38b are not limited to this preferred configuration and the first and second intermediate ribs 38a, 38b may be separated into multiple segments, preferably such that at least one of the segments of the first and second intermediate ribs 38a, 38b is intersected by the lateral axis <NUM> at generally any location along the height of the fill sheets <NUM>, 9a, 9b, as is described in further detail below with respect to the intake and outlet side ribs <NUM>, <NUM>.

The first and second inlet and outlet side ribs 24a, 26a, 24b, 26b of the first preferred embodiment are comprised of a plurality of rib segments 70a, 70b, 70c, 70d, 80a, 80b, 80c, 80d, wherein the first inlet side rib 24a is comprised of a first inlet side rib segment 70a and a third inlet side rib segment 70b, the second inlet side rib 24b is comprised of a second inlet side rib segment 70c and a fourth inlet side rib segment 70d, the first outlet side rib 26a is comprised of a first outlet side rib segment 80a and a third outlet side rib segment 80b and the second outlet side rib 26b is comprised of a second outlet side rib segment 80c and a fourth outlet side rib segment 80d. The first inlet side rib segment 70a includes a top end 71a and a first end 71b and the third inlet side rib segment 70c includes a fourth end 71e and a fifth end 71f. The second inlet side rib segment 70b includes a second end 71c and a third end 71d and the fourth inlet side rib segment 70d includes a sixth end <NUM> and a seventh end <NUM>. The first outlet side rib segment 80a includes a top end 81a and a first end 81b and the third outlet side rib segment 80c includes a fourth end 81e and a fifth end 81f. The second outlet side rib segment 80b includes a second end 81c and a third end 81d and the fourth outlet side rib segment 80d includes a sixth end <NUM> and a seventh end <NUM>. The inlet side rib <NUM> and outlet side rib <NUM> are configured such that at least one of the pluralities of segments 70a, 70b, 70c, 70d, 80a, 80b, 80c, 80d is intersected by the lateral axis <NUM> at any position between the top ends 71a, 81a and the seventh ends <NUM>, <NUM>, respectively. In contrast to the first and second intermediate ribs 38a, 38b, the rib segments 70a, 70b, 70c, 70d, 80a, 80b, 80c, 80d somewhat overlap in the height direction or the water flow direction, such as between the third and fourth ends 71d, 81d, 71e, 81e and the first and second ends 71b, 81b, 71c, 81c, for example. The rib segments 70a, 70b, 70c, 70d, 80a, 80b, 80c, 80d are not so limited and may be configured without the overlaps in the height direction and may include additional or less segments, although preferably such that at least one of the rib segments 70a, 70b, 70c, 70d, 80a, 80b, 80c, 80d of each of the inlet side rib <NUM> and the outlet side rib <NUM>, respectively, is intersected by the lateral axis <NUM> at any position between the top and bottom edges <NUM>, <NUM>. The inlet side ribs <NUM>, the outlet side ribs <NUM> and the intermediate ribs <NUM>, including the respective rib segments 38a, 38b, 70a, 70b, 70c, 70d, 80a, 80b, 80c, 80d, extend generally parallel to the vertical axis <NUM> or the intake and outlet sides 10a, 10b in the first preferred embodiment, but are not so limited and may be otherwise oriented and configured to provide strength and stiffness to the fill sheets 9a, 9b, <NUM>.

In the preferred embodiments, the inlet side rib <NUM>, the outlet side rib <NUM> and the intermediate rib <NUM> include the adjacent first and second inlet side ribs 24a, 24b, the first and second outlet side ribs 26a, 26b and the first and second intermediate ribs 38a, 38b, respectively. The pairs of the first and second inlet side ribs 24a, 24b, the first and second outlet side ribs 26a, 26b and the first and second intermediate ribs 38a, 38b are spaced at a lateral spacing SL that is preferably between <NUM> and <NUM> (one-quarter and two inches (¼ - <NUM>")). The lateral spacing SL is not limited to being between <NUM> and <NUM> (one-quarter and two inches (¼ - <NUM>")) and may be otherwise sized and configured based on fill sheet <NUM> loading, external loading factors, designer preferences, size of the fill sheet <NUM> and other design considerations. The lateral spacing SL of the first and second outlet side ribs 26a, 26b is shown in <FIG> and the first and second inlet side ribs 24a, 24b and the first and second intermediate ribs 38a, 38b are also similarly designed and configured to have the lateral spacing SL.

The inlet side rib <NUM> and the outlet side rib <NUM>, including first and second inlet and outlet side ribs 24a, 24b, 26a, 26b and have variable heights between the top and bottom edges <NUM>, <NUM>. As a non-limiting example, the outlet side rib <NUM> and, specifically, the second outlet side rib 26b includes the second outlet side rib segment 80b and the fourth outlet side rib segment 80d with a reduced height portion or portion with the minimum rib height Hn of the second outlet side rib 26b extending between the second outlet side rib segment 80b and the fourth outlet side rib segment 80d between the top edge <NUM> and the bottom edge <NUM>. The second outlet side rib segment 80b preferably has the rib maximum height Hx in the second outlet side rib segment 80b and the fourth outlet side rib segment 80d has the rib minimum height Hn in a portion between the second and fourth outlet side rib segments 80b, 80d. The second outlet side rib 26b of the preferred embodiment also includes transition portions <NUM> where the second outlet side rib 26b transitions between the rib maximum height Hx and the rib minimum height Hn along the length of the second outlet side rib 26b. Each of the intake side ribs <NUM>, 24a, 24b and the outlet side ribs <NUM>, 26a, 26b are preferably similarly configured to the second outlet side rib 26b, with the rib segments or portions having the rib maximum height Hx, portions or segments having the rib minimum height Hn and the transition portions <NUM> between the segments with the rib maximum and minimum heights Hx, Hn. In addition, the pairs of intake side ribs 24a, 24b and outlet side ribs 26a, 26b preferably have the transition portions <NUM> at generally the same lateral positions along the lateral axis <NUM> and opposing rib maximum and minimum heights Hx, Hn along the lateral axis <NUM> for the adjacent intake side and outlet side ribs 24a, 24b, 26a, 26b, respectively. As a non-limiting example, the second outlet side rib segment 80b preferably has the rib maximum height Hx along the lateral axis <NUM> while the adjacent portion or segment of the first outlet side rib 26a has the rib minimum height Hn.

The microstructure 11a in the heat transfer section <NUM> of the preferred embodiment has a microstructure height Hs. The minimum height or first rib height Hn is less than the microstructure height Hs in a first rib support portion, such as along the intake side and outlet side ribs 24a, 24b, 26a, 26b wherein the ribs 24a, 24b, 26a, 26b have the minimum height Hn. The maximum height Hx is, conversely, greater than the microstructure height Hs in a second rib support portion, such as along the intake side and outlet side ribs 24a, 24b, 26a, 26b wherein the ribs 24a, 24b, 26a, 26b have the maximum height Hx. The ribs 24a, 24b, 26a, 26b are not so limited and may have consistently smaller or greater heights than the microstructure height Hs, depending on design and requirement considerations of the particular fill sheet <NUM>. The ribs 24a, 24b, 26a, 26b are not limited to the described configuration with the alternating maximum and minimum heights Hx, Hn with the transition portions <NUM> therebetween and the microstructure height Hs being between the maximum and minimum heights Hx, Hn and may be otherwise designed and configured to support the fill sheets <NUM> based on designer preferences, loads being carried by the fill sheet <NUM>, external factors of the operating environment or other factors that may drive the design and configuration of the intake side and outlet side ribs 24a, 24b, 26a, 26b. The intermediate rib <NUM> may be similarly designed and configured as the intake side and outlet side ribs 24a, 24b, 26a, 26b with the maximum and minimum heights Hx, Hn and the microstructure height Hs sized therebetween, but is similarly not so limited, as is described herein. In addition, in the preferred embodiments, the intake side and outlet side ribs 24a, 24b, 26a, 26b and the intermediate rib <NUM> has a generally arcuate-shaped cross-section. The intake side and outlet side ribs 24a, 24b, 26a, 26b and the intermediate rib <NUM> are not limited to having the arcuate-shaped cross-section and may have alternative cross-sectional shapes, such as solid, squared, triangular or other shapes, as long as the intake side and outlet side ribs 24a, 24b, 26a, 26b and the intermediate rib <NUM> are able to perform the preferred functions and withstand the normal operating conditions of the intake side and outlet side ribs 24a, 24b, 26a, 26b and the intermediate rib <NUM>, as is described herein.

The preferred intake side and outlet side ribs 24a, 24b, 26a, 26b include the transition portions <NUM>, which has a substantially consistent first taper, therein the intake side and outlet side ribs 24a, 24b, 26a, 26b transition from the minimum or first rib height Hn to the maximum or second rib height Hx. The transition portions <NUM> are not limited to having the substantially consistent first taper and may have staged, stepped, sudden or otherwise inconsistent tapers between various heights along their length, but the preferred intake side and outlet side ribs 24a, 24b, 26a, 26b have the relatively consistent first taper to assist in transitioning loads, for manufacturability, to limit stress concentrations and for additional design considerations.

Referring to <FIG>, in the second preferred embodiment, the fill sheet <NUM>' includes the integral drift eliminator <NUM>. The integral drift eliminator <NUM> of the second preferred embodiment is comprised of an angled tube integral drift eliminator type, with a blocking structure or rib <NUM> at a drift eliminator inlet <NUM> where air flow enters the drift eliminator <NUM> from the heat transfer area <NUM>' of the fill sheet <NUM>' in the fill pack <NUM>'. The blocking structure <NUM> is substantially comprised of a rib or wall in the preferred embodiment. The drift eliminator <NUM> is not limited to including the blocking rib <NUM> or to the blocking structure <NUM> being oriented generally vertically or to being a rib or wall. The blocking structure or rib <NUM> may be comprised of nearly any structure that provides an impediment or block for cooling fluid flowing directly into the drift eliminator <NUM> and facilitates drip formation at the inlet <NUM>, preferably on or proximate to the blocking structure <NUM> so that the cooling fluid drips do not form deep into the drift eliminator <NUM>. The cooling fluid is then able to drain back into the heat transfer area <NUM>' before exiting the drift eliminator <NUM> and being lost from the cooling tower.

The blocking structure <NUM> preferably provides a block to drift, typically comprised of cooled water droplets or cooling fluid, or formation of cooling fluid drips at the inlet <NUM> so that the cooling fluid does not flow deep into the drift eliminator <NUM>. Formation of drips at the inlet <NUM> generally prevents the fluid from flowing deep into the drift eliminator <NUM>, potentially escaping into the drift eliminator <NUM> and out of the heat transfer area <NUM>'. The cooling fluid captured at the inlet <NUM> of the drift <NUM> is preferably, ultimately maintained in the heat transfer area <NUM>' for further disappation of heat and eventually into a catch basin (not shown) below the fill pack <NUM>' or the individual fill sheets 9a, 9b, <NUM> in the tower (not shown). To prevent the cooled water or cooling fluid film that is flowing through the fill pack <NUM>' from travelling up and out of the tubes <NUM> of the drift eliminator <NUM> and out of the air outlet side 10b' of the fill pack <NUM>', the blocking structure <NUM> is added at the drift eliminator inlet <NUM> which acts as a barrier for the water film and a drip formation area to limit flow of the cooling fluid deep into the drift <NUM>. As the water or cooling fluid film reaches the blocking structure <NUM>, the film forms drips which enter the airstream near the drift eliminator inlet <NUM>, rather than farther into the drift eliminator tube <NUM> toward the air outlet side 10b. This change in the location of drip formation at the drift eliminator inlet <NUM> on the blocking structure <NUM> causes the droplet or drip to be introduced to the air stream in a location earlier in the transition of airflow direction, thereby causing the droplet or drip to impact a bottom tube wall of the drift eliminator tubes <NUM>. The drip from the drift eliminator inlet <NUM> is thereby removed from the airstream to improve performance and effectiveness of the drift eliminator <NUM> and the fill pack <NUM>', because the potentially lost cooled water or other cooling fluid film is blocked at the blocking rib <NUM> to facilitate drip formation at the inlet <NUM> to be captured by the drift eliminator tubes <NUM>. The water or cooling fluid, therefore, flows back into the heat transfer area <NUM>' through a drainage structure <NUM> for further disappation of heat and eventually into the catch basin below the fill pack <NUM>' during operation. In the second preferred embodiment, the blocking structure <NUM> is comprised of a pair of rounded ribs or walls measuring from approximately <NUM> to <NUM> (five hundredths of an inch to two tenths of an inch (<NUM>" - <NUM>")) in height and <NUM> to <NUM> (one tenth to one-half inch (<NUM>" - <NUM>")) in width. The blocking structure or ribs <NUM>, which are formed at the drift eliminator inlets <NUM> of each of the fill sheets <NUM>', 9a', 9b', align generally adjacent the top walls of each of the drift eliminator inlets <NUM> of the tubes <NUM> to act as a barrier for the water film to generally limit the water or other cooling fluid drift from moving into the tubes <NUM> or facilitate formation of drips to limit flow of the cooling fluid deep into the drift <NUM>.

The second preferred embodiment of the fill sheet <NUM>' also includes drainage structures <NUM> (<FIG>) positioned inwardly toward a center of the sheet <NUM>' relative to the drift eliminator <NUM>. The drainage structures <NUM> provide a flowpath for the water or cooling fluid blocked by the blocking structure <NUM> to flow back into the heat transfer area <NUM>' for further dissipation of heat. The second preferred fill sheet <NUM>' is not limited to inclusion of the drainage structure <NUM> and may inlcude alternatively configured features to direct the captured water or other cooling fluid back into the heat transfer area <NUM>' or no features without significantly impacting the structure and operation of the second preferred fill sheet <NUM>'.

Referring to <FIG>, in a third preferred embodiment, a fill sheet <NUM>" has similar features compared to the first and second preferred fill sheets <NUM>, <NUM>' and the same reference numerals are utilized to identify similar or the same features, with a double prime symbol (") utilized to distinguish the features of the third preferred embodiment from the first and second preferred embodiments. The third preferred fill sheet <NUM>" includes an intermediate rib <NUM>" including first, second and third intermediate ribs 38a", 38b", 38c". Each of the first, second and third intermediate ribs 38a", 38b", 38c" are laterally spaced from each other and include intermediate rib segments 90a, 90b, 90c, 90d, 90e, 90f, <NUM> that extend genereally vertically or parallel to the vertical axis <NUM>" to provide strength and stiffness to the third preferred fill sheet <NUM>".

Claim 1:
A fill pack for cooling heat transfer fluid in a cooling tower, the fill pack comprising: a first fill sheet (9a) having a first air intake side (10a), a first top edge (<NUM>), a first air outlet side (10b) and a first heat transfer area (<NUM>) between the first air intake side (10a) and the first air outlet side (10b);
a second fill sheet (9b) having a second air intake side (10a), a second top edge (<NUM>), a second air outlet side (10b) and a second heat transfer area (<NUM>) between the second air intake side (10a) and the second air outlet side (10b); and
an integral drift eliminator (<NUM>) associated with the first and second air outlet sides (10b) in an installed configuration, the drift eliminator (<NUM>) defining a plurality of tubes (<NUM>) with a drift eliminator inlet (<NUM>) positioned proximate the first and second heat transfer areas (<NUM>) and a drift eliminator outlet spaced away from the first and second heat transfer areas (<NUM>), the plurality of tubes (<NUM>) extending generally toward the first and second top edges (<NUM>) from the drift eliminator inlet (<NUM>) toward the drift eliminator outlet, each of the plurality of tubes (<NUM>) including a blocking structure (<NUM>) at the drift eliminator inlet (<NUM>) configured to block a film of the heat transfer fluid at the drift eliminator inlet (<NUM>) to promote droplet formation and direct the cooling heat transfer fluid back into the heat transfer area (<NUM>), the blocking structure (<NUM>) comprised of a pair of ribs,
wherein the pair of ribs is comprised of rounded ribs measuring from <NUM> to <NUM> (five hundredths of an inch to two tenths of an inch (<NUM>" - <NUM>")) in height and <NUM> to <NUM> (one tenth to one-half inch (<NUM>" - <NUM>")) in width.