Splash Bar For Cooling Tower Fill Assembly

Abstract

A splash bar for a cooling tower fill assembly is formed from a synthetic resin sheet material and is of transversely M-shaped open base configuration. The sides of the bar are solid and vertically short relative to the horizontal distance between the sides spanned by the top, which is perforated and has a shallow, V-shaped, transverse configuration. Accordingly, the top presents a pair of inwardly sloping splash surfaces merging intermediate the sides to define a longitudinal channel along the top, three drip lines thus being provided at the channel and the two sides.

Description

This invention relates to improvements in splash bars utilized in the fill assemblies of cooling towers and, in particular, to an improved splash bar of the perforated, sheet material type.

As a substitute for wooden slats in cooling tower fill assemblies, splash bars of sheet material have been introduced and utilized in actual practice. DeFlon, U.S. Pat. No. 3,389,895, which granted on June 25, 1968 and is owned by the assignee herein, discloses a fill or splash bar of sheet material construction that is lightweight and eliminates many of the disadvantages of wooden slats. Besides the scarcity and expense of redwood preferred for slats of this type, wooden slats are subject to deterioration by rotting and constitute a fire hazard during prolonged periods of shutdown of the cooling tower.

The preferred embodiment of the splash bar disclosed in the aforesaid DeFlon Patent is of inverted V-shaped transverse configuration to thereby present an open base, the walls of the bar being perforated to provide openings through which both the falling water and the air may pass in a crossflow cooling tower. The V-shaped configuration inherently causes the vertical dimension of this bar to be materially greater than that of splash bars of the wooden type. It has been found that, even though perforated, the pressure drop induced in the system by the V-shaped bar is greater than desired, particularly under high water loading conditions.

Accordingly, the primary object of the present invention is to provide an improved splash bar for crossflow cooling towers which does not produce an excessive pressure drop in the system when compared with conventional bars of wooden slat construction in relationship to the cooling efficiency thereof.

Another important object of this invention is to provide a splash bar as aforesaid having an increased width in order to increase the effective splash area, yet without presenting problems of support in the fill assembly due to the length of the span and also permitting fewer bars to be used in the fill than previously required.

Still another important object of the invention is to provide a splash bar as aforesaid having three drip lines for improved cooling performance as compared with the two lines of drips provided by prior splash bars of sheet material construction including the V-shaped bar discussed above.

In the drawing:

FIG. 1 is a fragmentary, elevational view of an induced draft, crossflow cooling tower, a portion of the casing being broken away to reveal the interior construction;

FIG. 2 is a fragmentary, enlarged elevational view taken at right angles as compared with FIG. 1 and looking into the air intake of the cooling tower;

FIG. 3 is a further enlarged, detail view of the fill assembly showing one of the splash bars in transverse cross section;

FIG. 4 is a fragmentary, plan view of the splash bar;

FIG. 5 is a perspective view of a length of the splash bar; and

FIG. 6 is a diagrammatic illustration showing the manner in which the top of the splash bar may be perforated.

An induced draft, crossflow water cooling tower 10 is illustrated in FIG. 1 and has a casing 12 surrounding the sides of a fill assembly 14 except for an open side which defines an air intake 16. The tower 10 has the usual hot water inlet 18, distributor 20, and hot water basin 22 at the top of the fill assembly 14, and a cold water basin 24 beneath the fill assembly 14. Airflow is induced by a fan 26 which directs air upwardly and outwardly through a fan cylinder 28.

The fill assembly 14 is supported by the various frame members 30 of the tower 10, as is conventional. Cross rods 32 mount the support structure of the fill assembly 14, such structure constituting a plurality of grids 34 spaced from one another and disposed in vertical planes. Each of the grids 34 comprises a number of horizontal elements 36 and intersecting, inclined elements 38 composed of a synthetic resin material such as a glass reinforced polyester. The elements 38 of the grids 34 are inclined rather than disposed at exact right angles to the horizontal elements 36 in order to compensate for the pullback of the water as it falls downwardly through the fill assembly 14. In this respect, it should be noted that the air entering the intake 16 flows in a generally horizontal direction through the fill assembly 14 in general parallelism with the horizontal grid elements 36.

A plurality of splash bars 40 are supported by the segments 36a of the horizontal grid elements 36, such segments 36a being the longer segments of the elements 36 between adjacent inclined grid elements 38. One of the bars 40 is shown in detail in FIGS. 4 and 5 where it may be seen that the bar 40 is elongated and has an open base configuration, being formed by sheet material having the shape of an "M" as viewed in transverse cross section. Accordingly, the bar 40 has a pair of longitudinally extending, upright sides 42 which are solid throughout, and a longitudinally extending top 44 integral with the sides 42 at their upper longitudinal edges and spanning the sides 42. The top 44 is perforated and thus has a multiplicity of openings 46 therethrough.

As viewed in transverse cross section, the top 44 has a shallow, V-shaped configuration; thus, the splash area of the top 44 is presented by a pair of splash surfaces 48 which slope downwardly and inwardly from the upper edges of the sides 42. At the zone of merger of the two surfaces 48 intermediate the sides 42, such surfaces 48 define a longitudinal channel 50 along the top 44 which extends the entire length of the bar 40. The sloping splash surfaces 48 present a line of drips at the channel 50 as illustrated by the broken line 52 in FIG. 3. Two other lines of drips 54 are formed by the upright sides 42, each of the latter being provided with an outwardly projecting, longitudinally extending, solid flange 56 integral with the lower longitudinal edge 58 of the side 42, thereby presenting a foot which rests on the segment 36a. Additionally, the flanges 56 increase the structural rigidity of the sides 42 to minimize sagging of a span of the bar 40 between a horizontally spaced pair of grid segments 36a.

A synthetic resin material such as polyvinyl chloride is preferred for the sheet construction of the present invention. The bars may be extruded in long lengths and then perforated while in a flat condition due to the memory of the material. This is illustrated in FIG. 6 where the bar 40 is shown between male and female perforating rolls 60 and 62. Once free of the rolls, the sheet material returns to the M-shaped configuration seen in FIGS. 3 and 5. As is clear, only the top 44 is perforated, thereby leaving the sides 42 and associated flanges 56 entirely solid.

To facilitate the securing of the bars 40 to the grid segments 36a, ties such as illustrated at 64 in FIG. 3 looped through adjacent openings 46 and around the segments 36a may be employed. The bars 40 are arranged in spaced, superposed interrelationship to form a number of inclined columns of horizontal bars 40, as may be seen in FIG. 1.

By way of exemplary dimensions, the vertical height of the bar 40 (the sides 42) may be 1 inch with an overall width of approximately six inches. A sheet material thickness of 0.030 inch is satisfactory. Accordingly, it may be appreciated that the sides 42 of the bar 40 are vertically short relative to the horizontal distance therebetween spanned by the top 44. Since the bars 40 extend transversely of the direction of airflow through the fill assembly 14, minimum resistance is presented to the flowing air by virtue of the relatively small bar height. However, the splash area is large relative to the vertical height. This may be appreciated when it is considered that grid structures as illustrated at 34 have been previously used to support wooden bars, in which case the horizontal segments 36b were used to support the wooden bars rather than the longer segments 36a. Therefore, the present invention provides comparable splash area in a design that is still sufficiently lightweight and strong to preclude excessive sagging. In this respect, it should be noted that the sides 42 are solid and upright to provide the necessary structural rigidity for long spans, and are augmented in their function by the integral flanges 56 which are coextensive therewith. As the water loading increases, it may be expected that the underside of the top 44 beneath the channel 50 will sag sufficiently to engage and overlie the grid segments 36a supporting the span.

As water falls onto the splash surfaces 48 of each bar 40, even distribution of the water is assured since some droplets will pass directly through the openings 46 and continue to fall until encountering a splash surface presented by another bar 40 therebeneath. Other droplets will be disbursed by splatter upon contacting the splash surfaces 48, or by filming or spreading out over the surfaces 48 whereupon the water either runs over the sides 42, forming the two drip lines 54, or is directed toward the channel 50 where the line of drips 52 is formed.

Claims

1. In a crossflow cooling tower where airflows in a generally horizontal direction through a fill assembly, the combination with the support structure of the fill assembly of:

an elongated, generally horizontal splash bar of sheet material supported by said structure and extending transversely of said direction of airflow,

said bar being of open base configuration and having a pair of longitudinally extending, solid, upright sides, and a longitudinally extending top integral with said sides and spanning the latter,

said top being provided with a pair of splash surfaces sloping downwardly and inwardly from respective sides,

said surfaces having a multiplicity of openings therethrough for passage and dispersal of liquid falling thereupon.

2. The splash bar as claimed in claim 1,

said sides being vertically short relative to the horizontal distance between the sides spanned by said top.

3. The splash bar as claimed in claim 2,

said top being of shallow, generally V-shaped transverse configuration,

said surfaces merging intermediate said sides to define a longitudinal channel along said top,

said sides and said top thereby defining an M-shaped configuration transversely of the bar with said channel and said sides providing three lines of drips for liquid dispersed by said surfaces.

4. The splash bar as claimed in claim 2,

each of the sides having a lower longitudinal edge provided with an outwardly projecting, longitudinally extending, solid, integral flange presenting a foot resting on said structure.

5. The combination as claimed in claim 1, further including:

a plurality of said splash bars supported by said structure in spaced, superposed interrelationship.