US2919896A

US2919896A - Apparatus for raising tank shells

Info

Publication number: US2919896A
Application number: US621639A
Authority: US
Inventors: Frank L Wurst
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1956-11-13
Filing date: 1956-11-13
Publication date: 1960-01-05
Anticipated expiration: 1977-01-05

Description

F. L. WURST Jan. 5, 1960 APPARATUS FOR RAISING TANK SHELLS Filed Nov. 13, 1956 4 Sheets-Sheet 1 fiwdjzzwaz M i J.

Jan. 5, 1960 F. L. WURST 2,919,896

7 APPARATUS FOR RAISING TANK SHELLS 'lFiled Nov. 13, 1956 4 Sheets-Sheet 2 Wis,

Jan. 5, 1960 Filed Nov. 15, 1956 F. L. WURST 2,919,896

APPARATUS FOR RAISING TANK SHELLS 4 Sheets-Sheet 3 Jan. 5, 1960 F. WURST APPARATUS FOR RAISING TANK SHELLS 4 Sheets-Sheet 4 Filed NOV. 13, 1956 United States Patent APPARATUS FOR RAISING TANK SHELLS Frank L. Wurst, Chicago, Ill., assignor to Chicago Bridge & Iron Company, a corporation of Illinois Application November 13, 1956, Serial No. 621,639

' 3 Claims. or. 254-105 "This invention relates to jack assemblies and methods for using them in jacking shells of large storage tanks.

In some instances, owners of petroleum storage, tanks have found that property values have increased to such an extent that it is desirable to increase the capacity of existing storage tanks by increasing the height of the tanks. In addition, it has frequently been found that old storage tanks have corroded to such an extent that the plate thickness is insufficient to assure safe containment of the products being stored because the lower course of plates may no longer be adequate, although if used in the second course, the thickness would be adequate because of the lower stresses to which the second course is subjected. It is, therefore, desirable or necessary to replace the lower course and to lift the former lower course above the new lower course. If desired, the old top course may be removed, and/or two lower courses of shell plates may be replaced.

After the tank shell has been lifted, new shell plates may be inserted under the existing shell and welded or riveted in place; the existing shell may then be attached to the new lower course by Welding or riveting it to the upper edge of the new lower course.

It has been found, however, that the use of conventional screw-type or hydraulic-type jacks, together with cribbing or other support means, is unsatisfactory for the purpose of jacking tank shells. One of the reasons that these conventional lifting structures are unsatisfactory is that the tank shell must ordinarily be jacked to a height of about eight feet; conventional jacks cannot be used at this height without intermittently interrupting the operation in order to underpin the shell while the jack is removed and lowered to its initial operating position and placed on cribbing, at which time the procedure is repeated. This procedure is so cumbersome and dangerous that it is seldom attempted.

My invention contemplates a jacking assembly which may be used in lifting the shells of cylindrical, rectangu lar, or polygonal storage tanks, and is illustrated as being used upon tanks of from approximately 60 feet in diameter to about 150 feet or more in diameter. The jack assembly permits the shell to be expeditiously and safely lifted for operations such as described above. In structures of the sizes indicated, it is necessary to provide a suflicient number of jack assemblies to support the substantial weight of the tank shell and to prevent any appreciable amount of distortion of the tank shell during the lifting operation.

The jack assemblies which are the subject of this invention are designed to utilize the ordinary screw-type or hydraulic-type jack, with a limited distance range of lifting (e.g., 12 to 18 inches) without requiring temporary .shoring, cribbing, or underpinning between successive lifts.

The invention will be described by reference to the accompanying diagrammatic drawings, in which:

Figure 1 is a plan view showing the orientation of a plurality of my jacking assemblies;

ice

Figure 2 is a top plan view of one of the jack assemblies shown in Figure 1; v Figure 3 is an elevation view of the assembled apparatus taken on the line 33 of Figure 2;

Figure 4 is an elevation view taken on the line of Figure 3;

Figure 5 is an enlarged detailed view taken on the line 5-5 of Figure 2; and

Figure 6 is an enlarged detailed view of a portion of:

the assembly shown in Figure 4.

As can readily be seen from the drawings, the apparatus consists of a plurality of suitably braced jacking assemblies 10, each having

support posts

12 and 13, having a number of vertically spaced holes 15 and 16 through which pins 17 and 18, respectively, may be passed to ac-.

commodate a jacking beam 21. The beam 21 may be raised by arm 24 which rests on the lifting head 37 of a conventional lifting jack. The beam 21, in turn,-

supports a box-like shell support member 25 which surrounds the ram 24 and is secured to and rises vertically- I from the beam and is attached to the tank shell 27 by means of lugs 26 welded to the inner surface of the tank shell. As shown in Figure l, a sufiiciently large number of these jacking assemblies are employed around the tank so that the entire tank shell 27 may be raised.

' The

support posts

12 and 13 are attached to a base- 11 at their lower ends and to a cap assembly 14 at their upper ends. The pins 17 and 18 in turn pass through and support

collars

19 and 20 which underlie and may support the beam 21. The beam 21 may also be.sup-.

ported at certain times by a pin 22 which is inserted in holes 23 in the ram 24.

. The assembly is given radial and lateral stability b y means of parallel

radial bracing members

28 and 29,

34 and 35. The

bases

11, 34 and 35, and 30 and 31 are attached (e.g., welded) to the bottom 36 of the' tank.

Figure 1 schematically shows the manner in whichtwelve of my jacking assemblies may be radially located along the periphery of the bottom of a storage tank having a diameter of about 117 feet. The

radial bracing members

28 and 29 are shown placed generally parallel to radii of the tank bottom and the

chord bracing members

32 and 33 are shown placed generally along chords of the periphery of the bottom of the tank. Thus, the assemblies are located within the periphery of the bottom of the tank so that when the shell is finally jacked to its highest position, the space underneath it will be unobstructed so that new lower course shell plates may be placed in position and attached to the bottom of the tank at the vertical edges of adjacent shell plates as well as to the bottom edge of the jacked-up shell. It is possible to locate the assemblies outside the shell, rather than inside, if suitable supporting means are provided for their bases.

In operation, the shell is severed from the tank bottom and the jacking assemblies are first placed in proper position along equally spaced radii of the bottom of the tank. Next, after the bases have been properly secured (e.g., welded) to the bottom of the tank, the shell sup port member 25 is attached to the lugs 26 which, in turn, are attached to the lower portion of the shell. The ram 24 extends axially through the shell support member 25, so that the support member 25 serves as a guide; the ram 24 is supported at its lower end by the lifting head 37 of the jack. Pin 22 is inserted into a hole in the beam 21, as shown in Figures 5 and 6, so as to affix the beam 21 to the ram 24. The same procedure is fol- Patented J an. 5, 196i);

lowed with respect to all of the jacking assemblies which are located around the bottom of the tank.

The lifting operation is commenced and carried out simultaneously for all the jacking assemblies, so that the entire tank shell will be lifted uniformly and without distortion. As the jack assemblies approach the upper limit of their extension, the jacking operation is stopped; the pins 17 and 18 which attach the

collars

19 and 20, respectively, to the

support posts

12 and 13 are then removed, the

collars

19 and 20 are raised, and the pins 17 and 18 are reinserted through the highest holes 15 and 16 which appear below the beam 21. Each jack head is then lowered sufficiently for the beam 21 to come to rest on the

collars

19 and 20, at which point the pin 22, which connects the beam 21 to the ram 24, is removed. The lifting head 37 of the jack is then lowered to its lowest position so that the ram 24 is moved downward with the lifting head, but the shell support member 25 is held in place by the beam 21 which in turn is held by the

collars

19 and 20 as Well as pins 17 and 18. When the lifting head is lowered as far as it can go, the pin 22 is re inserted in the lowest available hole 23 in the ram 24, thus connecting the ram 2 4 to the beam 21 for the next jacking operation. As jacking continues, the beam 21 continues to rise with the ram 24 and the lifting head, and the collars 19 and 21} are again reset by means of the pins 17 and 18. This procedure is repeated until the tank shell has reached a height sufficient to enable the placing of a new course of shell plates underneath it. When the new shell plates are attached to the bottom of the tank as well as the adjacent edges of other new shell plates, the old shell may be lowered so as to be connected to the upper edge of the new course; the jacking assemblies may then be removed and the joint between the new course and the lower edge of the old shell may be welded. It is preferred to make temporary connections of the old shell to the new shell prior to removal of the assemblies.

During the jacking operation, and particularly when the shell has been jacked up a distance of several feet, there exists a danger that the lower end of the ram 24- may be kicked out of place by sliding off of the lifting head 37, and it may, therefore, be desired to attach a guard at or near the lower end of the ram. This guard may be of the general shape of beam 21 and may be affixed to the

supports

12 and 13 and have a hole through which the ram 24 may be guided.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

What is claimed is:

1. A jack assembly for lifting structures such as the metal shells of storage tanks and the like vertically and free from the ground, comprising a base, a pair of vertical supports extending upwardly from said base, a laterally extending beam spanning said supports and being guided for vertical movement thereby, securing means for selectively fixing said beam to said supports in any one of a plurality of vertical positions, a single vertical jack having vertical lifting means positioned below said beam, a vertically movable ram having its lower end positioned to engage said jack lifting means to be moved thereby, releasable securing means for selectively fixing said beam to said ram so that vertical movement of said ram will move said beam vertically along said supports, shell supporting means engageable by said beam and having shell attaching means whereby said shell is raised by said jack when said shell supporting means is fixed t0 the ram, said ram and jack lifting means being lowerable independently of said shell supporting means and beam, said pair of vertical supports being capable of supporting said beam when the ram and jack lifting means are lowered independently of said shell supporting means and beam, and bracing means secured to said assembly so as to maintain said assembly in substantially vertical alignment during its operation.

2. The jack assembly of claim 1 wherein the shell supporting means circumscribes a portion of said ram and serves as a guide for said ram.

3. The jack assembly of claim 1 wherein said vertical supports comprise a pair of parallel vertical posts flanking said ram.

References Cited in the file of this patent UNITED STATES PATENTS 2,304,354 Harvey Dec. 8, 1942 2,449,781 Jameson et a1. Sept. 21, 1948 2,631,008 Kroll et al. Mar. 10, 1953 2,794,242 Evers June 4, 1957