US2636371A - Mechanical draft water cooling tower - Google Patents

Description

April 28, 1953 F. M. STEPHENS MECHANICAL DRAFT WATER COOLING TowER 2 SHEETS-SHEET l Filed April 3, 1950 IN V EN TOR.

. Y nliiiilllllliilld .nlmlllillihhllmw April 2s, 1953 F. M; sPHENs 2,636,371

` MECHANICAL DRAFT WATER vCOOLING TOWER Filed April 3. 195o 2 SHEETS- SHEET 2 IN VEN TOR.

Patented Apr. 28, 1953 was MECHANICAL DRAFT WATER COOLING?A TOWER Foster li/LHStephens, Monterey Park, Calif., assignor to The Fluor Corporation, Ltd., Los Angeles, Calif., a corporation ofv California Application April 3, 1950, k.Serial No. 153,585

1 claims. (o1. sofista vThis invention hasvto do generally with improvements in lair-cooled heat exchange equipment of the type used for industrial and large capacity cooling or condensing of liquids and gases, and having the structure of a vertically extending `chamber through which air is displaced upwardly from inlets in one or both lower sides of the chamber by a power driven fan.l The heat exchanger or fluid cooling tubes are positioned in the path of the air stream after its entry to the chamber, for example as by arrangement in banks located above the fan in an induced air flow type of equipment or unit. c

As willbe understood, the .Cooling capacity of the unit is dependent in considerable measure upon the temperature of the atmospheric air and consequently, normally where the unit is designed for operation in a given location, itsv overall size (and therefore cost) is Subj-ect to variations according to the expectable maximum atmospheric temperatures in that location. Suchumaximum temperatures, on the other hand, may exist only during a short seasonal period, but nevertheless, the equipment must be designed for that condition, notwithstanding that for operation during the remainder of the year, the equipment may be considerably oversized. Particularly is this true since it is found most feasible to operate the fan at constant speed, rather than to attempt to vary the cooling capacity of the unit by Icontrolling the fan speed.

In accordance with the invention, provision is made for controlling or varying the temperature of atmospheric air being displaced at substantially constant rate by the fan against the exchanger tubes, to an important end result of avoiding having to oversize the'unit (with relation to normal operation requirements) in order to meet the abnormal conditions existing during warm weather. Specicially, provision is made for precooling the air in advance of the exchanger, by direct and intimate contact with water so that, ifdesired, the inlet air can be lowered below its atmospheric temperature and toward the wety air. while it is to `te' 'understood that paging 5K;

2, venticnbroadly contemplates use of any suitable structurethus capable of extensively filming the water in intimate exposureto the inlet air, I may cite as typical, the use of one or a series of. frames removably positoned at or within the chamber inlets and containing masses of fiber or Strandlike material, such as wood excelsior, which not only films the water but effectively filters the air for removal of dirt particles.

Another -major consideration given the water filming medium is that it be capable ofeffecting intimate and extended surface contacts between the Water and air, and yet impose no excessive resistance (and therefore a load upon the fan) to the air passage therethrough. Specifically, the invention contemplates the provision of water filming surfaces of such arrangement and extent as to present to air being displaced therethrough and at velocities under 500 feet per minute, a resistance not in excess of about 0.15 inch of Water as measured bythe pressure differential at opposite sides of the lming medium or material. Accordingly, in using wood excelsior as a water filming and air contacting material, the excelsior is but lightly compacted and used in a quantity or thickness sucient to present the water-air interfaces necessary for cooling and filtering of the water, while giving the material sufficient openness to avoid excessive air pressure drop in flowing therethrough.

All the various features and objects, as well as the details of an illustrative embodiment, will be understood more fully from the following descriptionof the accompanying drawings, in which:

Fig. 1 is a general view illustrating in perspective a corner portion of the equipment;

Fig. 2 is a fragmentary cross section take transversely through the lower portion of the structure of Fig. 1 and in the plane of line 2-2;

Fig. 3 is an enlarged fragmentary elevation showing the outside Water distributing header and the air-cooling panels below; Y

l Fig. 4 is a vertical section on line 4 4 of Fig. 3,

' extended to include the collecting trough at the bottom of the panel; and

Fig. 5 is an enlarged fragmentary section on line 5-5 of Fig. l. V v

. While thegeneral structure of the equipment, as to the shape and arrangement of the housing or chamber walls, may be subject to variation in accordance with preferred specic designs, I have shown as typical, the cell frame structure to comprise an externalframework including end columns l0, intermediatel horizontal members I l, andtopfhrizontal braces, .l t.` The. endn of the structure above member II is formed by a vertical wall I3, and extending along opposite sides of the structure from the end wall, are inclined Walls I4, terminating at the top in vertical extensions I5. The heat exchanger tubes I5 may be suitably mounted, as by the walls I5, and arranged inupper and vlower tube banksgl'l and. I8.A

Referring-to Fig. 2; the wall structure thus deflnes vertically extending chambers I9 divided by partition extending longitudinally of the' structure, it being understood thatieachchamber I9 constitutes a cell and that an entire air cooling structure may include any number of cell pairs I9 in end to end relation; dependingfjupon the designed cooling capacity ofthe equipment.y For more particular details concerning structures of this type, reference may behadltio. theapplif.-

cation of George H. Dieter, Serial No 627,987, filed November 13, 1945,on Air-Cooled -Ieat Exchangers.

Th'e'vchambers-:I Acontain-av horizontal floor 2 I5 within'- which is=placed the :usual fan rings 22. 1in-.- dlviduallyencircling.` a -fa-n 23` drivenas by: way ot shaft Ziiefrom a .corn/entionallyl illustrated lmotor orother power unitl25.= The-fans operateto inducel air rlow-N into Vthehbottorns' of the charn-` bers .19 through spaces at 28 belowthe walls i3 and i4, which may belleit-'open as indicated at 26a in Fig. l, or closed bythe air-passing panel` assemblies 2. portions of fthe chamber l Sl;l the air :isi-dischargedbythe fansupwardly.in` high. velocity heat-ex` change contact.withthe-exchanger tubes Ii as previously indicated during normal .or cooler weather conditions,- the panels 2l may bere-v moved 4so. Vthat air: at atmospheric temperature and humidity isdrawn openly into-the ian chambers-.throughthe openings a; At such times as-'the atmosphericaintemperature may rise to the point vrhereinproper cooling differential cannot be :maintainedby the temperatures of the air outside and. iluid inside the tubes I6, the panels 'i-maybemounted as shown in Figs. 1 and 2, in order that the inletiair may be temperature conditioned` in advance of its Contact with kthe exchanger tubes;

As particularly illustrated in-Figs. 3V to 5, each panel 2'! `comprises a rectangular yframe 28 adapted to be secured by suitable fasteners 29 to -the corner columns It andihorizontal members II,

thebottoms of the panels :bei-ng rested on a suitable:support` IBil. Adjacent sides: of. successive frames may be -interconnectedorattachedV to theverticalsupports 30, by appropriate fastenersfSI.' Secured to each face'of the panelis an openerrangernent of Ywires- ESI- spaced suiicientlyA close.

to retain l the `water-filmingV material 32.

Typically, the material `.'Zmayhave a strand or berflike form, such as wood excelsior, whichV is-compacted between `the wires |31 to a degree sufficient torequire the air to pass `in, intimate. and dirt-filtering Contact 'with the surfacesl of the excelsior, the latter however lbeing.:suiiicient ly loose to avoid excessive air; pressure drop through the panels. By reasonofthe tendency, oftheiniiowing air to displace.- water, inwardly and in the direction of the air flow, it maybe, ole.- sirable to provide for redistribution-of the f water during ther-course of its now. downwardly through' the panels. shown 4to Containl avertical series of linclined baf-` les,.;!325 which serve` to: collect and redirect thedown fiowing water :from `theoutlet i toward f the Y air; inlet :side orl the panel.

Watereisedelivered itcfthetopsofl 'the-panels 21 i After beingdrawn into .the lower .Accordingly-A,` in;-,Fig;Y 4; the panel is@ by way of headers 33 `mounted to the frame members I I by brackets 34 and connected to a supply pipe 35, the headers being perforated at 36 (see Fig. 3) for uniformly distributed and restricted feed to the panels. Uniformity of water delivery at the desired rate mayK be facilitated by covering the'v headers v33 with a porous A(e. g. felt-like) material "ST'held'to the headers by clamps 38. there being at the underside of the header a depending saw-tooth web 39 from which the Water drips continuously into the excelsior iillings of the panel 2l. Ordinarily water is fed to the panels at a rate sufficient for the Water to pass completely downxthrough Vthe excelsior. Any residual ywater is collected'lin troughs 40 underlying the panels and leading to a sump.

As willibe-aplarent from the foregoing, by reason of its intimate contact with the extended Water :Filming surfaces of the excelsior masses 32, the inlet air becomes cooled during the course ofitspassagethrough the-panels, to a' degree constituting av majorm approach to Ythe4 Wetv bulb temperature, and which may be as much, typical-i ly, as l5 degrees below the atmospheric air'tem perature. Bymaintaining the .a-ir owethrough the panels at a rate below the water-entraining velocity, theY cooled air displaced by the -fan` upwardly against the exchanger tubes may be kept substantally iree'from liquid particles tending; to deposit on the exchanger surfaces.

l' claim:

l. In mechanical draft air-cooling heatl exchanger equipment, walls forming a vertically extending chamber, a horizontal wall in said chamber, a fan in an opening in said horizontal wall and operating to produce displacement of air in aV stream flowing into the chamber throughan inlet in its lower side wall below saidhorizontal wall andY thence upwardly therethrough, a heat exchanger in the path of the air stream above the fan, a fra-me verticallyT andv removably positioned in said inlet below saidhorizontal Wall and containing anbrous mass, and' means for; continuously lming the surfacesof,saidmass with water.

2. In mechanical dra-ft air'fcooling; heat, ex'-A changer equipment, walls forming a vertically extendingv chamber; a horizontal wall'v in said chamber, afan in an opening in said horizontal; wall and operating to produce displacement of` air in a stream flowing into the chamber-through an inlet in its lowensidewall below said`hori- Zcntal wall andl thence upwardly therethrough, a heat exchangerin thepath-of the air stream above the fan', a frame vertically and removably positioned in -saidinlet below said horizontal ,wall and containing a fibrous mass of 'wood excelsior.,` and meansfor ycontinuously filmingY the ,surfaces of said mass with water.'

3. ln mechanical dra-ft air-cooling heat exchanger equipment, wallsl forming a vertically; extending chamber, a horizontal wall inl said chamber, a fan in ari-opening in saidhorizontal' wall and operating-to producev displacement,r of j air inra-stream flowing into Vthe chamber through` an inlet; in its lcwer-side wall below sai-d horiif zontal lwall and thence upwardly therethrough,l a heat exchanger in the -path'of the-airstream above the fan; a frame vertically-and removably, positioned in said inlet below said'horizontal wall' and-containing a brous mass,v means at the-top of said framefor passingwvater in uniform dis-l tribution downwardly over the surfaces ofsaidi mass, andwatercollecting means, at the ,bottom of-saidmass.-

4. In mechanical draft air-cooling heat exchanger equipment, walls forming a vertically extending chamber, a horizontal wall in said chamber, a fan in an opening in said horizontal wall and operating to produce displacement of air in a stream iiowing into the chamber through an inlet in its lower side wall below said horizontal wall and thence upwardly therethrough, a heat exchanger in the path of the air stream above the fan, a frame vertically and removably positioned in said inlet below said horizontal wall and containing a fibrous mass, means at the top of said frame for passing water in uniform distribution downwardly over the surfaces of said mass, baille means within said mass for redistributing water against displacement out of the mass in the direction of air flow therethrough, and water collecting means at the bottom of said mass.

5. In mechanical draft aircooling heat exchanger equipment, walls forming a vertically extending chamber, a horizontal wall in said chamber, a fan in an opening in said horizontal wall and operating to produce displacement of air in a stream owing into the chamber through an inlet in its lower side wall below said horizontal wall and thence upwardly therethrough, a heat exchanger in the path of the air stream above the fan, a horizontal series of frames vertically and removably positioned in said inlet below said horizontal wall and containing fibrous masses presenting large surface areas, and a water supply conduit extending above said frames and from which water is fed into said fibrous means for 'downward flow therethrough.

6. In mechanical draft air-cooling heat exchanger equipment, walls forming a vertically extending chamber, a horizontal wall in said chamber, a fan in an opening in said horizontal wall and operating to produce displacement of air in a stream flowing into the chamber through an inlet in its lower side wall below said horizontal wall and thence upwardly therethrough, a heat exchanger in the path of the air stream above the fan, a horizontal series of frames vertically and removably positioned in said inlet below said horizontal wall and containing brous masses presenting large surface areas, means oletachably interconnecting adjacent frames, and a water supply conduit extending above said frames and from which water is fed into said brous means for -downward flow therethrough.

7. In mechanical draft air-cooling heat exchanger equipment, walls forming a vertically extending chamber, a horizontal wall in said chamber, a fan in an opening in said horizontal wall and operating to produce displacement of air in a stream flowing into the chamber through an inlet in its lower side wall below said horizontal wall and thence upwardly therethrough, a heat exchanger in the path of the air stream above the fan, a horizontal series of frames vertically and removably positioned in said inlet below said horizontal wall and containing brous masses presenting large surface areas, and a water supply conduit extending above said frames and from which water is fed into said brous means for downward ilow therethrough, said fibrous masses presenting to air owing therethrough at velocities under 500 feet per minute a pressure drop not in excess of 0.15 inch of water.

FOSTER M. STEPHENS.

Referenees Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,861,158 Hilger May 31, 1932 1,883,778 Freeman Oct. 18, 1932 2,270,810 Larriva Jan. 20, 1942 2,310,843 Ditzler Feb. 9, 1943 2,353,233 Gygax July 11, 1944 2,450,191 Fienberg Sept. 28, 1948

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