US2683550A

US2683550A - Elevated tank

Info

Publication number: US2683550A
Application number: US218690A
Authority: US
Inventors: John F Mummert
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1951-03-31
Filing date: 1951-03-31
Publication date: 1954-07-13
Anticipated expiration: 1971-07-13

Description

y 1954 J. F. MUMMERT 2,683,550

ELEVATED TANK Filed March 31, 1951 3 Sheets-Sheet l illilfillliillllllllllii July 13, 1954 J. F. MUMMERT 2,683,550

ELEVATED TANK Filed March 31 1951 S Sheets-Sheet 3 Egg. 6?

I /0 i i; ii ii f L. I i x w I #0 I I 4/ v ,1 5 4 4/ i I 4/ i [3 I? I? 172062751: f0%/?J%JWZW6% Patented July 13, 1954 UNITED S TAT- ES ELEVATED TANK John F. Mummert, Birmingham, Ala., assignor to Chicago Bridge & Iron Company, a corporation of Illinois Application March 31, 1951, Serial N 0. 218,690

3" Claims. '1

This invention relates to an elevated storage tank.

Elevated storage tanks are employed for the storage of liquids such as water. Thesetanks have been constructed according to many different designs that consist of a storage portion, a supporting framework for the storage portion, and a foundation,- usually of concrete, under the supports. Many of the elevated tanks built in the past have disadvantages in that the foundation is ordinarily quite bulky, and there are problems of getting equal loading on the foundation. If one portion of-the foundation settles more than the other portions, strains areset up in the tank and in the supports.

I have invented an elevated storage tank comprising a storage portion, -a support means for the storage portion concentrating the load on a relatively small area and. permitting the vertical movement of the storage portion under load. There is also provided a bracing means resisting any substantial sideways movement of the storage portion but permitting vertical movement thereof. In this construction the weight of the storage portion and the contents is concentrated on a relatively small area so that the problem of uneven loading of the foundation is substantially eliminated. The actual design of the new elevated tank may vary widely so long as the storage portion is supported on a central member and bracing means are provided to resist sideways movement but to offer very little or no resistance to vertical movement, due to the elasticity of the support. The bracing means maybeconnected with the storage portion by'pivoted members which permit relative movement between the storage portion and bracing means and/or may be totally disconnected withthe storage portion to remove all or substantially all of thebending moment in the riser supporting the'storage portion, which moment is caused by wind' pressure and the like.

The invention will be described'as related to one embodiment of the same, as set-out in the accompanying drawings. Of the drawings,'Fig. 1 is an elevation of a storage tank embodying the invention; Fig. 2 is a vertical section taken along line 2-2 of Fig. 1; Fig. 3 is a horizontal section taken along line 3-3 of Fig. 1; Fig. 4 is-similar to Fig. 1 and shows the'bracing-structureutilized without connection tothe storage portion; Fig. 5 is a fragmentary vertical section through a portion of the storageportion and'the surrounding ring and bracing structure; Fig.6 is an elevational view of an alternate construction wherein the bracing structure comprises a ring placed about the riser'pipe; Fig. '7-is-a'fragmentary-sectional view takenas indicated by line 1 1 in Fig. 6; and Fig. 8 is-afragmentary vertical-section through'the lower portion of the storage portion of the tank and the riser pipe showing the bracing structure thereabout.

Referring particularly to "Figs. 1 and' l, the

elevated storage tank shown comprises a storage portion IE, a combined riser pipe and support II for the storage portion, and a framework bracing l2 around the storage portion 7 I0 and riser: pipe I I. The riser pipe I I rests on a concrete foundation I3, while each leg of the bracing I2 rests on foundations I l. The riser pipe II and its foundation I3 carry substantially the'f-ull weight of the storage portion I 0 and the liquid contents of the tank. As can be seen, the entire weight is concentrated on the foundation I3 which covers a relatively small area.

In the embodiment shown in Fig. 6, the storage portion I0 is supported upon a riser pipe-I I resting upona foundation I3 adapted to support the entire elevated structure with the exception of the bracing. The bracing structure comprises a ring-40 supported by a number of tubular legs 4I, herein shown as three in number, equally spaced about the riser pipe. In this embodiment the entire weight of the tank and contents is supported on the foundation I3 and the bracing structure resists sideways movement of the storage tank by bearing againstfoundations'fl for the tubular legs ll.

When the tank is filled and emptied of'liquid there will be avertical movement set up due to the elasticity of-the steel in the riser pipe I I. The bracing I2 which comprises four legs I5, cross cables I8, struts 25, and a circular platform I! surrounding the storage portion H], is arranged so that it will not restrict the vertical" movement of the tank, but will serve only'to'prevent any substantial sideways movement due to Wind'and the like. The bracing'is purposely'made relatively light in weight, as it is not subjected to any portion of the weight of the tank and its contents.

In order that the bracing I2 will not inhibit the vertical'movement'of the'tank, the bracing is either unconnected to the tank or connected by movable members. If the bracing is unconnested, a clearance 'of approximately inch between the'top 'of'the bracing and'the tanklll may be provided ashorizontal deflection of this amount would not "result in undue stress. In the embodiment shown the top of each'leg I5 of the bracing is connected to the storage portion ii) of the'tank by means of substantially horizontal bars I8. 'Each' bar I8 is rotatably attached to the storage portion ID by means of clevis plates I9 extendingfrom thestora'ge portion-I0. A clevis plateh'l is provided'on each-side of each bar it and a pinZIl 'passes through'theclevis plates I3 and the'horizontalbar 2-0. The opposite end of each bar I8 is also rotatably mounted on the legs I5 by means of a second pin 21 passing through two gussetplates 22 and the horizontal bar. I8. .A gussetplate is arranged on either side ofthe bar I8. Thesegusset plates are of substantially triangular shape, and'serve not only as an end supportlfor'the horizontal bar I8 t also a s pports forthehorizontalportion 23 of the platform 17. There is a substantial clearance between the inner end of each gusset plate and the storage portion H] of the elevated tank.

A plurality of substantially horizontal collars Z l are provided around the riser pipe ll. These collars are attached to the legs 55 of the bracing i2 by means of substantially horizontal struts 25. The collars 24 are attached. to the riser pipe II as by welding while each strut 25 is attached to a collar by means of a flat vertical plate 26 on the collar and a pin 32 connecting the strut and the plate. The outer end of each girder 25 is attached to a leg I5 by means of a second plate 2! attached to a leg [5 with a second pin 33 passing through the girder and the plate 27. Bracing 28 is provided on each strut 25 so as to strengthen the strut, and aid it in resisting bending. Thus each strut is rotatably held at its two ends.

Referring particularly to the structure illustrated in Figs. 4 and 5, the bracing means 52 is entirely unconnected from the storage portion or the riser pipe. The bracing is accomplished by means of a stiff platform I? having a horizontal portion 23 which may serve as a catwalk about the storage portion. The platform I? is annular in shape and has an inner member 33 which is spaced approximately A; inch from the plates of the storage portion when the tank is centered within the bracing means. This platform 47 is rigidly held in position on a plurality of legs 15 suitably braced by cross cables it and supported upon individual foundations it. A gusset plate 22 is provided at the upper end of each leg l5 to provide additional rigidity between the legs [5 and the platform [1. Any wind pressure against the storage tank which causes lateral movement thereof will be resisted when the tank moves sufiiciently to come in contact with the inner portion 38 of the platform H. Bending moment introduced into the tank structure is thus transferred to the bracing structure and carried to the individual foundations l4. While the riser pipe II is sufficiently strong to withstand some bending moment, it is desirable to remove a substantial portion thereof so that the riser may be made considerably lighter than would otherwise be necessary.

In the embodiment of the invention illustrated in Figs. 6-8, the bracing ring 40 is placed about the riser pipe a short distance below the bottom of the storage portion I0. Wind pressure acting upon the storage portion creates bending moment in the riser i l which may be transferred to the bracing structure provided the ring 49 is glven sufficient vertical width and is made to fit the riser pipe closely. While the ring st fits closely about the riser pipe, sufficient clearance is provided to permit relative vertical movement between the riser and ring. Any number of bracing legs 4! may be provided and it is desirable to provide at least three to gain the requisite stability. The bracing structure may remove all of the bending moment introduced or may remove a portion of the bending moment, leaving the riser to resist the amount not taken up by The storage portion [0 may have any shape desired. That shown comprises a generally cylindrical body 29 having a cone top 30 and an inverted cone bottom 3!. The riser pipe H is connected to the tank at the apex of the inverted cone bottom 3|.

The invention is particularly useful in constructing storage tanks having relatively small capacities, such as not more than 50,000 gallons. The size will generally depend upon the thickness of steel used in constructing the riser pipe I I and upon the resistance of the foundation to compression. In the new storage tank the bracing which resists sideways movement may be used as an erection tower and need only be built strong enough to resist movement of the tank due to wind and the like.

This application is a continuation in part of my application Serial No. 642,336, now Patent No. 2,567,958, filed January 19, 1946.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

I claim:

1. An elevated liquid storage tank structure, comprising a storage portion, a centrally located riser pipe adapted to support the entire storage portion and contents above the ground, a cen tral foundation for the riser pipe, said riser pipe being incapable of supporting the storage portion against substantial sideways movement and means for bracing the tank against substantial sideways movement including, a plurality of columns about the riser pipe laterally spaced therefrom and extending upwardly to a height less than the height of the riser pipe, a ringlike member carried on the upper portions of said columns, said ring-like member and columns being rigid and said columns being capable of preventing substantial sideways movement of the ring-like member, said ring-like mem her being closely spaced from and encircling the riser pipe adjacent the storage portion concentrically when the riser pipe is centered over said central foundation, said columns and ringlike member preventing movement of the storage portion in excess of permissible movement of the riser pipe from said concentric position to a position in contact with the ring-like memher.

2. An elevated liquid storage tank as specified in claim 1 in which said columns carrying said ring-like member are tubular and extend in straight lines between the ground and said ringlike member.

3. An elevated liquid storage tank as specified in claim 1 in which said columns are tubular and are arranged symmetrically about the riser pipe and at least three columns being provided for said bracing means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,997,808 Blackburn Apr. 16, 1935 2,299,647 Murphy Oct. 20, 1942 2,567,958 Mummert Sept. 18, 1951 FOREIGN PATENTS Number Country Date $7,376 Germany July 23, 1927