US2086131A - Elevated water tank - Google Patents

Description

July 6, 1937. J O JACKSON 2,086,131

ELEVATED WATER TANK Filed Oct. 27 i955 Patented July 6, 1937 UNITED STATES P E T mar,

ELEVATED WATER TANK- James 0. Jackson, Crafton, Pa. I Application October 27, 1933; Serial No. ($5,467

5 Claims. (Cl. 220-69)- My invention relates to elevated water tanks supported by steel towers. I

Such tanks as heretofore constructed have been provided either with a flat base extending to the vertical side .of the tank, the base being supported by pillars throughout the area of the flat bottom -;or a hemispherical bottom hasbeen employed supported by pillars located at the peripheryof the .bottom. The latter type of tank'while offering many advantages over the flat bottom tank has the distinct disadvantage that the variation in the head of water contained in it be tween the full and empty water levels is so great as to render this type of tank objectionable in many installations. This unsatisfactory condition created a demand for elevated tanks with smaller ranges of head than were possible with hemispherical bottoms and the bottoms were therefore made hemiellipsoidal in shape in which the range of head as compared to the tank diameter was considerably reduced. As the dernand grew for tanks of still larger capacity, it became increasingly diflicult to use the hemiellipsoidal form of :bottom because of the large tensional stresses'in. the central portions of such' At" the same time the further refinements of mu-;

bottoms arising from their relative flatness.

nicipal water works systems required tanks of more uniform pumping operations.

It is the purpose of my invention to produce an elevated water tank having advantages not possessed by prior tanks while eliminating many of, their disadvantages. My new type of tank is provided with a bottom having its central portion substantially flat while a substantialp'artof the bottom. between the flat portion and the side of the tank is inclined downwardly and inwardly substantially'tangent to the bottom. Supporting pillars are provided under the side of v the tank and under the fiat bottom only, no pillars being employed under the toroidal portion of the bottom.

When the tank is filled with water a column of the water having the same diameter as the still smaller ranges of head in order to' permit ing of cost and an improvement in ance'of the tank. By utilizing mytoroidal construction ofytank it is possible, for instance, to -eliminate over one half of the grillage and girder beams required for a flat bottom tank at the sacrifice of only aboutseven percent of thetotal volume. of the tank while maintaining the advantages of small variation in head of the waterand this small reduction in capacity can be neutralized .by a trivial increase in diameter of the tank.

Referring to the accompanying drawingyFlg. 1 is a side elevation of an elevated water; tank contstructed in accordance with. this invention,

thesupporting columns andthe riser pipe being broken away shortly below their upper ends. Fig. 2 is anenlarged cross-section of Fig. .1, the

\ section extending from one side of the structure to some" distance beyond thevertical center of the tank. Figf 3. is an enlarged section on the line 3-3 on Fig. 1. sections on the lines onFig'. 3., f

On the drawing, I designates a tank shell hav ing the upper cylindrical portion II and the lower toroidal portion I2 which has its upper edge welded to the lower edgeof the cylindrical-pore 3 The lower end of thercur-ved lateral I tion. i I. v wall of the toroidal portion I2 is closed bythe bottom I3 which is substantillyfla't-or slightly convergent toward its center.;

Figs. 4 and 5 are vertical 4 4 and 5-5 respectively.

the appear- The tank shell is supported-by a steel tower.

tion II" of the tank and the upper portion of the toroidal portion I2 by welding or other. securing having the outer ringv of columns I twhich have theirupper endssecured to the cylindrical. por-.

means.- Within the ringof columns are two 1 rings of columns I5'concentricwith the-outer;

ring of columns. rings are arranged in pairs, each pair being radially positioned in vertical planes conceived as projecting from the axial center of the tank.

The columns I5 support a grillage composed of radial girders I6, each supported on a radial pair of columns I5, and the grillage beams I'l having theirends r supported by the radial girders I6.

The columns'of the two inner The outer ends of the radial girders have welded to them a circular girder I8 and the inner ends of these girders have the circular girders I 9 welded to them. The girders I6 and the beams I! are preferably I-beams, but theymay have other shapes if desired. The ends of the beams I! are fitted beneath the upper flanges of the girders I6 and are connected to the webs of the girders I 6 by the angles 20 riveted both to the circular girders.

beams and the girders I6, but the girders and the beams I'Lmay' be secured together by other means, such as welding. It will be noted that the beams I! are arranged in the perimeters of a series of polygons, one within another, the upper faces'of the girders l6 and the beams. l1 all lying atabout the same level or slightly inclined toward the center of the bottom.

The'lower edge' of the curved portion of the toroid 2 is welded to the upper face of the circular girder I 8. The bottom of the toroid is made up of .a series of steel plates 2 I, each plate spanning the space between the consecutive radial girders IS, the ends of the plates being welded to the upper surface of the radial girders. The

plates 2| between each two consecutive radial girders are arranged edge to edge to form a continuous surface. The lateral edges of the plates rest upon the beams and are welded together so as to form seams of polygonal shape overlying the longitudinal centers of the polygonal series of beams. The lower faces of the plates are welded to the beams as well as to the radial and The bottom within the outermost girders I1 is formed of nearly triangular areas converging toward'the center of the bottom. The end edges are welded-along seams 23 overlying the longitudinal centenof the radial girders. All of the welds in the bottom are supported by the girders and beams which are arranged on the lines of the natural expansion of the tank so that there is practically no liability of strains which will cause leaking along the seams, if the welds have been correctly made. Plates 2| are welded to the outermost plate 2i of each section and to the outercircular girder I8.

24 designates a verticalrlser pipe having its upper end coincident with the opening 25 in the bottom of the tank. The upper end of the riser pipe is secured to the bottom'of the tank in any satisfactory manner as by welding or riveting. The riser pipe and the columns l4 and l5 are supported on suitable foundations, not shown.

26 is a roof for the tank which may be omitted if desired. The two columns l5 which support a radial,

girder it are so positioned ments at the three substantially equal.

that the bending mo- -The inner ends of the radial girders and the circular girder I! are spaced a substantial distance from the riser pipe 24 so as to allow the annulus oi. the bottom between the riser pipe and. the circular girder I9 to have suflicient vertical deflection due to the expansion and contraction of the riser pipe.

Iclaimza 1. An elevated tank structure comprising a circular flat bottom portion bounded by a toroidal points of contra-flexure are wall portion rising from its periphery extending outwardly and upwardly therefrom, said flat portion and said toroidal portion dividing the supporting bottom area into two substantial supporting areas, said flat bottom portioncomprising sheet metal, girder reinforced throughout its area, and having posts thereunder to sustain the weight on the fiat bottom, 2. containing shell circular in horizontal cross section connected to the outer periphery of the toroidal portion, and circumferentially spaced posts attached to the shell and having sufficient strength and proportions to sustain the weight of liquid vertically above the said toroidal portion.

2. An elevated tank structure comprising a circular flat bottom portion bounded by a toroidal wall portionrising from the periphery of said flat bottom portion and extending outwardly and upwardly therefrom, said fiat bottom portion and said toroidal portion dividing the supporting bottom area into two substantial supporting areas, said flat bottom portion comprising a sheet metal fioor, means reinforcing saidfloor and maintaining it in substantially fiat condition against warping, and means under thefiat bottomvportion of sufllcient'strength to sustain the weight of liquid vertically above the said flat bottom portion, a

containing shell circular in horizontal cross sec--' tion connected to the outer periphery of the toroidal portion and circumferentiallyspaced posts attached to theshell and having sufiicient strength and proportions to sustain the weight of liquid vertically above the said toroidal portion.-

3. An elevated tank structure comprising a circular flat bottom portion bounded by a toroidal wall portion rising from the-periphery of said flat'bottom portion and extending outwardly and upwardly therefrom, said flat bottom portion and said toroidal portion. dividingthe supporting bottom area into two substantial supporting areas,

said-flat bottom portion comprising, a sheet metalx floor, means reinforcing said floor and maintaining itin substantially flatcondition against warping, and means under the flatb'ottom portion of sufficient strength to sustain the weight of liquid verticallyabove the said flat bottom portion, and circumferentially spaced posts attached to the upper periphery of said toroidal portion and havingsufficient strength and proportion to sustain the weight of liquid vertically-above the said toroidal portion. a 4. The combination asjdefined in claim 3 in which a sheet metal riser said flat bottom portion.

5. The combination as defined in claim 2' m' which the said containing shell is cylindrical in shape.

, JAlldES O. JACKSON.

is flexibly atta'chedtoi

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