US2427676A

US2427676A - Spherical tank

Info

Publication number: US2427676A
Application number: US580428A
Authority: US
Inventors: George T Horton
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1945-03-01
Filing date: 1945-03-01
Publication date: 1947-09-23
Anticipated expiration: 1964-09-23

Description

Sept 23, 1947. e T. HORTON 2,427,676

SPHERICAL TANK Filed March 1, 1945 2 Sheets-Sheet 1 M fimlldlliL George W 2 ZMM fi/ r/ V I III? lillfl n I II I. v

p 1947- s. T. HORTON 2,427,676

SPHERICAL TANK v Filed March 1, 1945 2 Sheets-Sheet 2 a II I Wm i Patented Sept. 23, 2947 srnnarcar. TANK George T. Horton, Chicago, 111., assignor to Chlcago Bridge to Iron Company, a corporation of Illinois Application March 1, 1945, Serial No. 580,428

9 Claims. (01. 220-1) This invention relates to elevated tanks for the storage of fluids, and relates particularly to a spherical tank supported on circumferentiallyspaced columns.

It has been found in the past that elevated tanks, and especially spherical tanks, are subjectedto expansion and contraction caused by the heat of the sun, changes in temperature caused by the weather, variations in pressure, and the like. These expansions and contractions sometimes tear the tank loose from its supporting legs or columns and thus many of these tanks require frequent and expensive repairs. They are especially bothersome with spherical tanks as it is difiicult to attach supporting columns to the tank, this being usually done by welding the columns to the sides of the tank at points below the horizontal equator. As the columns are welded to the tank at an angle, any loosening of the welding by expansion or contraction immediately brings the weight of the tank to bear on the weakened portion and tends to tear the whole column loose. A tank so supported tends to rock back and forth and this fact increases the problem of providing adequate support for the spherical tank.

I have discovered how spherical tanks can be constructed so that the forces of expansion and contractions of the tank are nullified and do not afiect the weld between the supporting column and the tank. I have also discovered a simple way of bracing the tank so as to prevent it from rocking about any axis. I accomplish these results by providing columnar supports which are attached to the spherical tank so that when the tank expands and contracts, the column at the, point of attachment will also expand and contract. I also provide tie rods at the bottom of the tank running to certain of the columns in order to brace the tank against any rocking action. For greater stability, these tierods are arranged substantially in the form of an equilateral triangle.

The invention will be described in detail as related to the embodiment of the same set out in the accompanying drawings. Of the drawings, Figure 1 is an elevation of a spherical tank built according to the principle of this invention; Figure 2 is a plan view of the spherical tank of Figure 1 with tie rods shown in dotted lines; Figure 3 is a vertical section taken along line 33 of Figure 1; and Figure 4 is a horizontal section taken along line 4-4 of Figure 3.

In the embodiment shown in the accompanying drawings, a spherical tank I is supported on a plurality of circumferentially-spaced vertical columns ll. At the bottom of certain columns are provided angular tie rods i2 extending from said columns to the bottom portion of the spherical tank Ill. These tie rods are in the form of a Substantially 60 angle with a column in the angular poration and the two ends of the rods attached, as by welding. There are provided three of these tie rods and an end of one is substantially aligned and overlapping with the end of another. They are arranged so that when viewed from above they form a substantially equilateral triangle as shown in Figure 2.

Each of the supporting columns is of a hollow construction and is attached to the tank at the top end I! at a position beneath the horizontal equator oi the tank. Where the column contacts the tank there is a cut-out portion out along a surface having the same shape and curvature as the corresponding portion of the spherical tank. This cutout portion ordinarily will not exceed substantially two-thirds of the diameter of the column. The resulting edges of the cutout portion are attached to the tank by welding. On

top of each column there is provided a rounded cap i4 having a sphere-contacting edge portion of the same curvature as said spheres and attached to the column and to the sphere by welding. The proportions of the cutout portion are of course such as to secure proper balance. The depth of the cut is also such as to provide adequate surface and flexibility.

Within each column ll there is proportioned one or more flat angular discs l5 to reinforce the column.

At the bottom of each of three equally spaced columns there is provided an angular tie rod [2. These angular rods form substantially a angle and are positioned with one of the columns in the angle and with the two legs of the rods welded to the bottom of the tank. The end of one tie rod is aligned with and overlapped by an end of another rod. This gives the tie rod assembly the appearance of an equilateral triangle when viewed from above, as is shown in Figure 2. Such a triangular arrangement gives greater stability to the structure and prevents the sphere from rocking.

As the top ends of the columns are attached to the sphere in a cut out portion, as explained hereinabove. and the resulting edges only of the columns are welded to the sphere, thecontacting portion of the column is able to expand or contract by spreading when the sphere expands or contracts. Thus the welded portion is placed under no excessive strain and there is no tendency for the column to tear loose from the sphere. This has a decided advantage over the prior methods of building such spherical tanks as it reduces repair work on the sphere supporting structures to a It is, of course, apparent that in order for the column to flex with the expansion and contraction of the spherical tank it is necessary that the column be made of a flexible steel and not some material like cast iron, or the like, that is inflexible.

This method of attaching supporting columns to spherical tanks has still another advantage in that it permits the top of each column to bend and thus adapt itself to transverse forces such as wind blowing against the side of the tank which tend to shift the position of the tank. Thus the invention allows the columns to give with forces exerted in and on the tank and prevents the columns from being torn loose by these forces.

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

I claim:

1. A spherical storage tank comprising a hollow sphere and a plurality of circumferentiallyspaced tubular columns supporting said sphere, each of said columns contacting the sphere at an area near the top of the column and cut out in a surface having the shape of the corresponding section of the sphere and welded at the resulting edges to said sphere, and each of said columns having a rounded closed top portion with a sphere-contacting edge welded to the sphere, with all the welded sphere-contacting edges being substantially continuous.

2. A spherical storage tank as set out in claim 1 wherein each of said columns has its top portion beneath the horizontal equator of said sphere.

3. A spherical storage tank as set out in claim 1 wherein three angular tie rods are provided each extending from a column to the sphere with each of said rods having a column in the angle and the two legs of the rod being welded to the sphere at the bottom of the sphere, said tie rods being arranged so that the end of a leg of one substantially overlaps the end of a leg of another and all three tie rods form substantially an equilateral triangle when viewed from above.

4. A spherical storage tank comprising a hollow sphere, a plurality of circumferentially-spaced tubular columns supporting said sphere, with each of said columns contacting the sphere at an area near the top of the column and being cut out in a surface having the shape of the corresponding section of the sphere and welded at the resulting edges to said sphere, and a rounded cap at the top of each column with each cap having a sphere-contacting edge portion of substantially the same curvature as said sphere and with each cap attached to the sphere and to the column as by welding, the sphere-contacting edge of said cap being substantially a continuation of the sphere-contacting edge of its column.

5. A spherical storage tank as set out in claim 4 wherein angular tie rods are provided extending from certain columns to the sphere with each of said rods having a column in the angle and the two legs of the rod being attached to the sphere.

6. A spherical storage tank as set out in claim 4 wherein angular tie rods are provided extending from certain columns to the sphere with each of said rods having a column in the angle and the two legs of the rod being welded to the sphere at the bottom of the sphere.

7. A spherical storage tank as set out in claim 4 wherein said cutout portions of each column do not exceed in maximum depth a distance substantially equal to two-thirds of the diameter of said column.

8. A spherical storage tank comprising a hollow sphere and a plurality of circumferentially-spaced tubular columns supporting said sphere, each of said columns contacting the sphere at an area beneath the horizontal equator of the sphere and near the top of the column and each column being cut out in a surface having the shape of the corresponding section of the sphere and welded at the resulting edges to said sphere, said columns each being capped at the top with a rounded cap having a sphere-contacting edge portion of the same curvature as said sphere and being ttached to the column and to the sphere as by welding, the sphere-contacting edge of said cap being substantially a continuation of the contacting edge of its column.

9. A spherical storage tank comprising a hollow sphere and a supporting structure, said supporting structure comprising a plurality of circumferentially-spaced tubular columns attached to the sphere at areas beneath the horizontal equator of the sphere and near the tops of the columns and each column being cut out in a surface having the shape of the corresponding section of the sphere to a depth not greater than the diameter of said tubular column and welded at the resulting edges to said sphere, said columns each being capped at the top with a rounded cap having a sphere-contacting edge portion of the same curvature as said sphere and being attached to the column and to the sphere as by welding, and three angular tie rods each extending from a column to the sphere and having a column in the angle with the two legs of the rod being welded to the sphere at the bottom thereof, said tie rods being arranged so that the end of a leg of one substantially overlaps the end of a leg of another and all three tie rods form substantially an equilateral triangle when viewed from above.

GEORGE T. HORTON,

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

UNITED STATES PATENTS Number Name Date D. 125,769 Horton Mar. 11, 1941 1,997,808 Blackburn Apr. 16, 1935 1,953,949 Boardman Apr. 10, 1934 2,156,400 Pechstein May 2, 1939 1,517,006 Horton Nov. 25, 1924