US2437484A - Cooling tower - Google Patents

Description

wk 9, 1948. I E. w. SIMCNS 3 COOLING TOWER Filed Jan. 22, 1945 5 Sheets-Sheet 1 IN l/EN TDR [ow/m0 W. JVMa/Va I .ATTDRIVE Y5 March 9, 1948. w SIMQNS 2,437,484

COOLING TOWER Filed Jan. 22, 1945 5 Sheets-Sheet 2 I} g E- I f g X \l\ IN VEN TOR. ZOWA'AD W. Suva/v5 ,07 TORNEYS,

March 9, 1948 w, SIMQNS 2,437,484

COOLING TOWER Filed Jan. 22, 1945 3 Sheets-Sheet 3 fig- 5.

INVENTOR. Eowzmo h. .S/MONS Patented Mar. 9, 1948 COOLING TOWER Edward W. Simons, San Francisco, Calif., as-

signor of one-half to George W. Null, San

Francisco, Calif.

Application January 22, 1945, Serial No. 573,899

9 Claims. 1

This invention relates to induced draft cooling towers and has for objects the provision of a more compact cooling tower having less height than heretofore without sacrificing the efiiciency and which tower is more economical to construct and to operate than heretofore.

Heretofore cooling towers of the induced draft type have used horizontally extending louvres across the inlet openings inclined transversely at 45 to horizontal, the inclination being downwardly from the outer or leading edge of each louvre. This type of grid ofiers considerable resistance to the flow of air into the tower and necessitates the use of a relatively tall tower in order to provide for admission of the desired amount of air. The slope of the louvres is mainly for the purpose of reducing the drift loss which still occurs where there is a substantial wind,

With the present invention the drift loss is practically eliminated and the height of the air inlets is reduced about 55% as compared with the height of said inlets in the conventional tower using louvres, which reduction is directly reflected in the height of the tower and in the amount of materials used. Economy in operation of the tower and in its construction is the direct result of the reduction in the height, inasmuch as the reduction in the height of the air inlets does not reduce the efiiciency of the tower.

Other objects and advantages will appear in the drawings and in the description.

In the drawings,

Fig. l is a part sectional, part elevational view of a tower of this invention, certain parts being more or less diagrammatically illustrated, such as the fan and motor.

Fig. 2 is an enlarged sectional view through a pair of the grid strips that extend across the air inlets at the lower end of the tower.

Fig. 3 is a sectional view showing one of the strips of Fig. 2 in plan view but broken in length.

Fig. 4 is a reduced fragmentary elevational view of a portion of the packing as viewed from the ends of the slats.

Fig. 5 is an elevatl'onal view of the slats of Fig. 4 broken in length and showing the end pieces holding the superposed rows of slats vertically spaced apart.

Fig. 6 is an enlarged fragmentary sectional view taken through several of the slats in an adjacent pair of rows showing about preferred proportions of the slats and spacings between slats and rows of slats.

In detail, the tower illustrated in the drawings is rectangular and has sheathing I on all four sides within outside comer posts 2, thus providing four imperforate side walls. A fan 3 driven by a. motor 4 is supported by a spider frame 5 or by any other suitable means within the upper open end of the tower for drawing air upwardly therethrough.

The corner posts 2 and posts 6 positioned intermediate the corner posts that are at the ends of two opposite sides of the towersupport the packing within said tower spaced above the outer concrete walls I of a well into which the water drops from the packing. Said walls may be of wood or of other suitable material instead of concrete.

The posts 6 are inside the sheathing I and carry cross beams I, 8 respectively above and below the packing, while corner posts 2 carry cross beams 9, I0 respectively, above and below the packing parallel with cross beams I, 8.

Above the packing and at right angles to cross beams I, 9 and below the latter are cross beams H supporting conventional water distributing pipes l2 that are connected with any suitable source of water, and below each of said pipes is a splash strip l3, This structure is not new but is common in cooling towers.

The cooling tower illustrated is preferably oblong in plan view, which is a usual shape, and Fig. 1 shows it in elevation from one of the shortest sides. It will be noted that the roof [5 is cut away for the propeller.

At the lower end of the tower and below beams III are air inlets l6 that are in opposed spaced relation, said inlets being in the longer sides of the tower and being defined by walls 1, posts 2 and beams l0, but they may be in the shorter sides. The shorter sides or the tower from beams III to the Well walls are completely closed by the sheathing.

Midway between inlets l8 and the two outer walls 1 that define the lower sides of said inlets,

the well is formed with a partition I! which may be apertured to provide for communication between opposite sides thereof below the water level. Supported on this partition is a vertical baille wall l8 that extends at its upper end between cross beams 8 that are carried by posts 8. This baflle is preferably imperforate, and as the packing in the tower is supported on beams 8, In, it will be seen that the air entering either of the inlets l6 will all be directed upwardly through the packing and irrespective of the strength of any outside wind, there will not be any drift loss through said inlets.

The packing within the tower illustratedin Fig. 1 comprises spaced superposed rows of horizontally extending spaced parallel slats 20 that are disposed in vertical planes with their greatest widths vertical. Thusly tiers of slats are provided and these tiers are arranged in two groups in Fig. 1 in opposite halves of the tower at opposite sides of a vertical plane extending through posts 6 and baille 18. Obviously onlyione group, of tiers or more than two groups maybe used; if

4 transversely thereof. (Figs. 4, 5). One such strip 30 for each row of slats is generally adequate, but more may be used if desired. Where one strip is used it is positioned intermediate the ends of the slats, and the notches are so formed as to relatively snugly receive the upper edges of the slats. These anti-warp strips are positioned on the slats ofieach'fsuc'cessive mat as the latter are successively positioned inthe tower.

The anti-warp means for the packing slats is desirable at all times but is particularly important where the slats are from resawn lumber. For expieces generally designated 22 at the opposite I ends of the slats of each group of tiers are supported on cross beams I0.

Theend pieces that have been generally desig nated 2|, 22 and which .may also be called tiering strips, are identicalat opposite ends of the slats, therefore the same numbers will be used for corresponding pieces. Said pieces at the ends of the slats are horizontal strips extending horizontallybetween opposite sides of the tower in its longest width, and which strips have their sides vertical and coplanar at said ends of the slats. They are arranged in pairs,'the :piecesii23, 24 at each end of the strips .of each tier being complementarily notched at 25 (Fig. 4) so that each notch will receive substantially half of a tenon 26 formedat the opposite ends of eachslat when the adjacent edges of the piecesz23, 24am together.

An inverted V-tongue and groove 21 are respectively formed on the adjacent edges of pieces '23, 22 respectively, to provide coplanar alignment of said pieces.

The pieces 23, 24 are preferably substantially uniform in vertical width and project above and below the upper and lower edges of the slats in the tier that they carry, said notches 25 being so spaced as to equally space the slats in each tier or row. The lower piece 24 of each pair 23, 24 is adapted to be supported at its lower edge on theupper edge of piece'23 of the pair of pieces therebelow, said adjacent edges being formed with the V-tongue and groove 21 the same as described for the edges of said pieces that are notched. Thus the adjacent tiers of slats are vertically spaced apart. However, the complementary notches 25 in alternate'pairs of pieces 23, '24 are offset laterallyso that the slats in adjacent pairs of tiers or rows are in staggered relation to each other. The degree of offset is preferably such as to position the slats of alternate tiers midwaybetween the slatsin the adjacent tiers, but above or below such adjacent tiers as the case maybe.

The end pieces at one of the-ends of the slats in each group -of tiers is supported substantially againstthe sheathing l, while the ends of the end pieces at theopposite ends of the slats are;

against posts 6. Thus the tiers of slats maybe quickly and accurately built up within thetower, and eaclrtier of packing slats with it's pairs of end pieces 23, 24 (which may be termed a mat) may be assembled outside the tower for positioning within the'latter.

' Anti-warp means for preventing warpageof the slats is provided for in the form of a horizontal strip 36 that -is notched at 3! along its lower edge toreceive the upper edges of the slats in each row whenthe saidstrip is laid across'said'slats ample, where two packing pieces 0.375 inch thick I are procured from pieces of one inch thickness.

When such lumber is resawn it tends to warp due to thereli'ef of tensions in the lumber.

In Fig.6 is shown a preferred arrangement of slats 2D with respect to proportions and spacings, and which proportions and spacings are indicated in multiples of the letter W, said letter referring to the width of each slat 20. As is indicated, where the vertical height of slats 20 is lOWor ten times the width of each slat, the spacing between tiers is preferably about 5W, or five times width W, and the center to center spacing between adjacent slats in each row is about 3.5W, or about three and one-half times the width of each slat 26. The width W is preferably about 0.375 inch.

The above spacings may vary. For example, the vertical height of slats may be from about 6W to about 15W. The spacing between tiers may be from about one to seven or eight times the thickness W and the center to center spacing between slats may be from about three to about six times the thickness W. As the spacing between the tiers of slats decreases the space between adjacent slats in each tier will increase. The preferred proportions and spacings give the best results, particularly where the slats are rectangular in cross-section and are relatively thin. The most important provision is the spacing between tiers, but the importance of this spacing is dependent upon the other dimensions and distances set forth, hence the mere spacing of the tiers is not sufiicient; 'It'might also be added that the variations that may occur may be formulized and the relationship between spacings and dimensions shown in Fig. 6 will come within such formula.

Across each inlet i 6 and spaced outwardly thereof, I provide a grid comprising a vertical row of horizontally extending, vertically spaced strips 35 (Figs. 1,2, 3) each of which is disposed in a substantially horizontal plane.

Vertical end members 36 are provided with opposedly opening transverse recesses 31 that receive the opposite ends of said strips (Fig. 2) and vertical stop-strips 38 are secured to the members 56 in positions extending over the ends of said recesses for holding the strips .35 in said recesses.

Sheathing 39 between members 36 and the tower-close the spaces between the said members and said tower, and the lower ends of members 36 may be supported on upward extensions -40 of the end walls 1 of the well that is below the tower. I

The stri s :in each grid are of streamline cross-sectional contour with the blunt end of such contour facing outwardly relative to the adjacent inlet l6 whereby there will be a minimum of resistance to the flow of air through the grids into the tower. The specific contour preferred is an airfoil contour substantially corresponding with that known as .NACA Airfoil No. 6521. The

contourshown in Fig. 2 is substantially identical with this contour. The initials NACA refer to the National Advisory Committee for Aeronautics.

It is to be noted that the airfoil contour preferred has a concave lower surface (transversely of strip 35) which has good lift characteristics at zero angle of attack, and at zero angle of attack the coefficient of drag is low and the coeflicient of lift is fairly high, being about 0.4. Other contours may be used, but the one shown in Fig. 2 and above described is preferred for the cooling tower of Fig. 1.

With the airfoil contour described, the upper surface of each slat has a slope inward to the tower, which slope would have an action comparable to that of a sill. This, together with the high wiping velocity generated over the upper convex surface of the strips 35 tends to convey any water that might be deposited on the strips into the tower.

The spacing between each of the grids and the tower is preferably about a foot in order that any tower drainage may find its way down the guiding surfaces of the tower posts and braces without contacting the grids themselves.

Anti-warp means may be provided for strips 35, which comprise a cylindrical dowel ii driven through coaxial openings formed in the strips. With a driving fit, the dowel in each grid would tend to prevent any warping that might otherwise occur. Of course several spaced dowels may be used if desired.

While the cross-sectional contour of the dowel is not strictly streamline, it generally approximates such shape and it may of course, be of strictly streamline contour.

The spacing between thestrips 35 may vary considerably, but where the width of each strip is between three and four inches and its maximum thickness is about 4 inch, a spacing of between two and three inches is satisfactory.

In the tower itself, and between the fan and pipes I2, I may provide a drift eliminator in the form of a pair of adjacent horizontal rows of spaced oppositely inclined horizontally extending strips 42. The strips of these two rows coact to provide angularly extending passageways between the fan and the packing against the walls of which the air will wipe thereby depositing any surplus moisture on said walls for dropping back onto the packing. In many instances this drift elimination is not necessary but in other installations it is quite valuable.

It is to be understood that the illustrations and the foregoing description are not to be considered restrictive of the invention, but merely illustrative of a preferred form thereof.

I claim:

1. An induced draft cooling tower having imperforate side walls enclosing packing and having means for causing upward movement of air through said packing, a pair of spaced opposed laterally directed air inlets at the bottom of said tower for admitting said air into the lower end of said tower, a grid extending across each of said inlets, each grid comprising a substantially vertical row of vertically spaced horizontally extending strips each disposed in a horizontal plane and of airfoil cross-sectional contour with the blunt end of each such sectional contour facing outwardly relative to the inlet across which the strip extends, the lower surface of said airfoil contoured strips being arranged at an angle relative to a horizontal plane and sloping downwardly in the direction of the trailing edge thereof.

2. An induced draft cooling tower having immeans for causing upward movement of air' through said packing, a pair of spaced opposed laterally directed air inlets at the bottom of said tower for admitting said air into the lower end of said tower, a grid extendingacross each of said inlets, each grid comprising a vertical row of vertically spaced horizontally extending strips each disposed in a substantially horizontal plane and of airfoil cross-sectional contour with the blunt end of each such sectional contour facing outwardly relative to the inlet across which the strip extends, the upper surface of said airfoil contoured strips being convex and the lower surface being arranged at an angle relative to a horizontal plane and sloping downwardly in the direction of the trailing edge thereof.

3. An induced draft cooling tower hlaving imperforate side walls'enclosing packing and having means for causing upward movement of air through said packing, a pair of spaced opposed laterally directed air inlets at the bottom of said tower for admitting said air into the lower end of said tower, a grid extending across each of said inlets, each grid comprising a vertical row of vertically spaced horizontally extending strips each disposed in a substantially horizontal plane and of airfoil cross-sectional contour with the blunt end of each such sectional contour facing outwardly relative to the inlet across which the strip extends, the upper surface ofeach strip being convex, and the under surface of each strip being slightly concave in direction transversely thereof from its point of greatest thickness toward the sharp end of each sectional contour.

4. An induced draft rectangular cooling tower having imperforate side walls enclosing packing and having means for causing upward movement of air through said packing, a pair of spaced opposed laterally directed air inlets at the bottomof said tower below two opposed side walls thereof and at a level below said packing, a grid extending across each of said inlets, each grid comprising a vertical row of vertically spaced horizontally extending strips each disposed in a substantially horizontal plane and of airfoil crosssectional contour with the blunt end of each suchsectiomal contour facing outwardly relative to the inlet across which the strip extends, the upper surface of said airfoil contoured strips being convex and the lower surface thereof being slightly concave in a direction transversely thereof from its point of greatest thickness toward the sharp end of each sectional contour.

5. An induced draft rectangular cooling tower having imperforate side walls enclosing packing and having means for causing upward movement of air through said packing, a pair of spaced opposed laterally directed air inlets at the. bottom of said tower below two opposed side walls thereof and at a level below said packing, a grid extend- .ing across each of said inlets, each grid comprising a vertical row of vertically spaced horizontally extending strips each disposed in a substantially horizontal plane and of airfoil crosssectional contour with the blunt end of each such sectional contour facing outwardly relative to the inlet across which the strip extends, a vertically extending anti-warp strip of streamline horizontal cross-sectional contour intermediate the ends of the strips in each grid securing said strips together to prevent warping thereof, the upper surface of said airfoil contoured strips being convex and the lower surface thereof being slightly concave in a direction transversely thereof from 7 its point of greatest thickness toward the sharp end of each sectional contour.

6. In an induced draft cooling tower havin imperiorate side walls and inlets at the lower end of said tower for admission of air into the latter, packing between said inlets and the top of the tower comprising superposed adjacent pairs of horizontal rows of horizontally spaced horizontally extending slats arranged in vertical planes with the slats in the rows of adjacent pairs arranged in staggered relation to each other, the said slats being of uniform vertical width and of uniform thickness, said width being between six and fifteen times the said thickness, the spacing between rows being between one and seven times said thickness and the center to center distance between the slats in each row being between three and six times said thickness.

7. In an induced draft cooling tower having imperforate side walls and inlets at the lower end of said tower for admission of air into the latter, packing between said inlets and the top of the tower comprising superposed adjacent pairs of horizontal rows of horizontally spaced horizontally extending slats arranged in vertical planes with the slats in the rows of adjacent pairs arranged in staggered relation to each other, the said slats being of uniform vertical width and of uniform thickness, said Width being about ten times said thickness, the spacing between rows being about five times said thickness and the center to center distance between the slats in each row being about three and, one half times said thickness.

8. In an induced draft cooling tower having imperforate side walls and inlets at the lower end of said tower for admission of air into the latter, packing between said inlets and the top of the tower comprising superposed adjacent pairs of horizontal rows of horizontally spaced horizontally extending slats arranged in vertical planes with the slats in the rows of adjacent pairs arranged in staggered relation to each other, the said slats being of uniform vertical width of and uniform thickness, anti-warp means securing the slats in each row together intermediate their ends, and a pair of superposed coplanar complementarily notched end strips at each of the opposite ends of the slats in each row securing said slats in spaced relation, and end portions of said slats being positioned in said notches and the adjacent edges of said strips being together.

9. In an induced draft cooling tower having imperforate side walls and inlets at the lower end of the tower for admission of air into the latter, packing between said inlets and the top of said tower comprising superposed adjacent pairs of horizontal rows of parallel horizontally spaced horizontally extending slats arranged in vertical planes with the slats in the rows of adjacent pairs arranged in staggered relation to each other, anti-warp pieces extending across the upper edges of the slats in each row transversely of the latter and formed with notches into which the said edges of said slats are fitted for preventing warping of the latter, said slats being of uniform thickness and of uniform vertical width and uniformly spaced apart in each row, means at the ends of the slats in each row spacing each adjacent pair of rows apart a distance between about four and about six times the thickness of each slat, the said thickness being from about one-eighth to about one-twelfth the vertical width of each slat, said means including spacing means for securing the slats in each row uniformly spaced apart from about three to about six times said thickness of each slat.

EDWARD W. SIMON S.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 444,558 Klein Jan. 13, 1891 1,747,288 Cofiey Feb. 18, 1930 1,872,599 Le Grand Aug. 16, 1932 2,197,970 Elmer Apr, 23, 1940 2,207,272 Simons July 9, 1940 2,239,936 Simons Apr. 29, 1941 2,247,514 Mart July 1, 1941 2,279,425 Voysey Apr. 14, 1942 2,356,192 Yingling Aug. 22, 1944 FOREIGN PATENTS Number Country Date 13,473 Great Britain July 2, 1901 16,635 Great Britain Aug. 16, 1905 543,110 Great Britain Feb. 10, 1942 627,081 France Sept. 26, 1927 543,273 Germany Feb. 3, 1932

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