US3033411A - Lifting apparatus for tank with floating roof - Google Patents

Description

May 8, 1962 J. BRUCKER ETAL 3,033,411

LIFTING APPARATUS FOR TANK WITH FLOATING ROOF Filed May 9, 1961 4 Sheets-Sheet 1 Fly. 1

3 16 I I4 I J INVENTORS JA mun BRUCKER pan/1n ouvt'ne'lb' ATTORNEYS y 1952 J. BRUCKER ETAL 3,033,411

LIFTING APPARATUS FOR TANK WITH FLOATING ROOF Filed May 9, 1961 4 Sheets-Sheet 2 5 INVENTORS JA c a uss BEL/c Kn Amm w May 8, 1962 i J. BRUCKER ETAL 3,033,411

LIFTING APPARATUS FOR TANK WITH FLOATING ROOF Filed May 9, 1961 4 Sheets-Sheet 3 IN vE/v roe: JA c Q DE: BRUClrF/P A Tron/van" y 1962 J. BRUCKER ETAL 3,033,411

LIFTING APPARATUS FOR TANK WITH FLOATINGROOF Filed May 9, 1961 4 Sheets-Sheet 4 V 1 fi j 14- g E? '1 IN VENTORS Mr G uzs REL/t km DAN/E puvER ms United States Patent Ofifice 3,033,411 Patented May 8, 1962 3,033,411 LIFTING APPARATUS FOR TANK WITH FLOATING ROOF Jacques Brucker, Paris, and Daniel Duvergie, Rois-Ctrlombes, France, assignors to Constructeurs Associes Pour le Montage dOuvrages Metalliques C.A.M.().M.,

Societe Anonyme, Paris, France Filed May 9, 1961, Ser. No. 108,839 3 Claims. (Cl. 220--18) Tanks of the type having a floating roof or dome are frequently used, notably for stocking various liquids, such as raw or refined hydrocarbons. A reservoir or tank of this type consists of a vessel bearing on the ground through a circular bottom and wherein the inner space is defined by a vertical cylindrical skirt or wall. This inner space is closed at its upper portion by a floating roof or dome consisting of a caisson having a circular contour which slides within said cylindrical wall with the interposition of sealing means therebetween, this roof floating direclty on the stocked liquid according to the level thereof, or resting on the bottom through vertical telescopic pillars adjustable in length when the tank is empty or even when this tank contains more than a quantity of liquid which i inferior to a predetermined limit.

When a tank of this character is erected on a soil of moderate firmness it is frequently observed after a certain period of operation that it sinks more or less regularly in the ground. During this movement the skirt or wall loses its verticality and the floating roof cannot operate in a satisfactory manner. It is then necessary to raise this roof to an extent sufiicient to permit the repair of the bearing disk or plate through which its bottom bears on the ground. As a rule this operation is carried out by using makeshift means and is therefore extremely difficult and inconvenient, due to the moderate strength of the tank which is normally dimensioned with a view to withstand only normal service eflorts and is therefore liable to distortion when it is raised above the surface by which its bottom is supported.

It is the essential object of the present invention to provide detachable means adapted, when necessary and with the assistance of few simple complementary means provided on the tank proper, to lift this tank through a simple manoeuvre excluding any risk of deformations. excluding any risk of deformation.

These detachable means comprise a set of hydraulic jacks or cylinders disposed at spaced intervals on the ground about the tank and adapted to exert an upward pressure on brackets carried by the outer periphery of the cylindrical wall, and a set of catenary suspension systerns extending radially about the axis of the tank, the carrier cable of each catenary suspension system extending diametrally through the circular aperture of the cylindrical wall by bearing on a pair of diametrally opposite pulleys carried by the upper edge of this wall, each sling of the suspension systems which is suspended from this carrier cable being anchored at two corresponding points of the roof and bottom respectively.

By supplying fluid under pressure to the hydraulic jacks or cylinders and maintaining the carrier cables of the catenary suspension systems under tension, the tank can be lifted without producing any distortion thereof, the bottom and roof structures being stiffened against the eflect of gravity by the traction exerted by the slings of which the anchoring points are properly and regularly distributed on the surface of said bottom and roof structures.

With the foregoing objects in view, the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawing in which:

FIGURE 1 is an axial section taken across the tank equipped with the tank lifting means of this invention;

FIGURE 2 is a plane view from above of the structure shown in FIG. 1;

FIGURE 3 is a detail view showing on a larger scale a fragment of FIG. 1 concerning one of the brackets with the hydraulic jack or cylinder associated therewith;

FIGURE 4 is a front elevational view showing one of these brackets;

FIGURE 5 is a detail view showing on a larger scale a fragment of FIG. 1 concerning one of the reinforcing frames for mounting one of the top pulleys;

FIGURE 6 is a view taken in the direction of the arrow Vi-VI of FIG. 5;

FIGURE 7 is a detail view showing on a larger scale' a fragment of FIG. 1 concerning the method of anchoring one of the suspension slings to the bottom and roof structures; and

FIGURE 8 illustrates the same elements as FIG. 7 but in their respective positions when it is desired to lift the roof in relation to the bottom, for example when it is desired to check the conditions of this bottom.

The floating-roof tank to which the lifting apparatus of this invention is particularly applicable comprises a tank consisting of a circular bottom 1 resting on the ground and a cylindrical skirt or wall 2 extending vertically upwards above this bottom. Slidably mounted in said cylindrical wall '2 is the floating roof structure 3 consisting essentially of a circular caisson floating freely on the liquid stocked in the tank when the latter is filled, adequate sealing means (not shown) being pro vided between the roof structure and the inner surface of said cylindrical wall. This tank is filled and drained by means known in the art which fit in the lower portion of the cylindrical wall and have not been shown as they are no part of this invention. The roof structure is solid with a series of pillars bearing with their lower ends on the bottom 1 when the tank is empty. Each pillar is telescopically adjustable in length and consists of a tubular member 4 in which an inner tubular rod 17 is fitted coaxially, each rod 17 being rigidly secured to the relevant pillar at the desired longitudinal setting by means of transverse pins 18 engaging pairs of diametrally opposite or aligned holes.

According to this invention, during the manufacture or, if desired and in order to avoid expenses which subsequently, for instance in case of reliable construction sites, might be deemed superfluous, when a lifting operation is deemed necessary, the outer periphery of the cylindrical skirt or wall 2 is reinforced in the vicinity of the bottom 1 by securing thereon a series of ring-shaped ribs 5. These rings 5 carry a set of brackets 6 extending radially from the outer surface of the wall 2. On the ground, around the wall 2, at a proper spacing from and beneath the outer arms of brackets 6, a concrete ring 12 is formed, as shown in FIG. 3. Slightly below its upper edge the outer periphery of the cylindrical wall 2 is reinforced by a stiffening annular structure or beam 7. Mounted on this stiffening beam 7 and overlying the brackets 6 respectively are a plurality of pulleys 8, each pulley being reinforced by an A-frame 9. Welded on the bottom 1 of the tank and beneath each pillar 4 is a ring or cylindrical member 10 engageable by the lower end of the pillar 4 when the tank is empty, a flange 11 being welded around the tubular member 4 slightly above its lower d edge to this end. In this position shown in FIG. 7, pairs of diametrally opposite holes formed in the tubular member 4 and in the cylindrical member are in axial alignment.

The apparatus according to this invention further comprises a set of hydraulic jacks or cylinders 13 adapted to be placed on the concrete ring 12 beneath the radially extending arms of brackets 6 respectively. Simple pins 14 threaded through the pairs of aligned hOles in the pillar tubular members 4 and relevant bottom cylindrical members 10 permit of anchoring the corresponding pillars and therefore the roof structure 3 carrying these pillars on the bottom 1. The equipment further comprises a series of catenary suspension systems, equal in number to the pairs of pulleys 8, which extend in diametrally opposite relationship on the upper contour of the cylindrical wall 2. The carrier cable 15 of each catenary suspension system is mounted diametrally above the aperture of the cylindrical wall 2 on a pair of diametrally opposite pulleys 8 for tensioning by means of lines extending on either side of the two pulleys 8 of the pair concerned. Each suspension cable 16 of the catenary suspension system is anchored to a hook 19 secured on the upper end of a relevant rod 17.

When the above-described apparatus has been disposed in the manner set forth hereinabove, the complete tank structure can be lifted by simultaneously tensioning the cables 15 of the diametral catenary suspension system and feeding fluid under pressure to the hydraulic jacks or cylinders 13 while maintaining the catenary suspension system under a constant, suitably adjusted tension. Thus, the complete tank structure can be lifted to the desired height Without causing any distortion in this structure, notably in its bottom 1 and roof 3, as the weight of these elements is compensated by the traction exerted by the suspension cables or slings 16 anchored on points disposed at spaced intervals over the surface of the bottom and roof structures 1, 3.

FIGURE 8 illustrates how the height of roof 3 above the bottom 1 can be increased without using the lifting apparatus when the tank is empty and it is desired for example to inspect this bottom and the lower face of the roof. This can be done by simply modifying, by sinking, the longitudinal setting of the inner rod 17 in pillar 4, in relation to the normal setting shown in FIG. 7, and by stifiening the pillar 17, 4 according to the desired degree of extension, by re-introducing the pins 18. When the tank is drained the roof structure 3 rests on the bottom 1 through the lower end of rod 17 and is thus located at a higher level with respect to the normal inoperative position shown in FIG. 7.

Although the present invention has been described in conjunction with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be Within the purview and scope of the invention and appended claims.

What we claim is:

1. For a liquid storage tank comprising a circular bottom bearing on the ground, a cylindrical wall extending vertically around said circular bottom and formed with an upper circular edge defining a circular aperture, a series of brackets secured around said cylindrical wall and a series of pulleys secured around said upper circular edge of the cylindrical wall, said pulleys being disposed at spaced intervals along said circular edge to constitute pairs of diametrally opposite pulleys, a caisson having a cylindrical contour in sealed sliding engagement in said cylindrical wall to constitute a floating roof structure on the liquid to be stocked in said tank, a series of vertical pillars extending through and rigid with said caisson, each of said pillars having beneath said caisson a lower bearing end adapted to support said caisson above said bot tom when said tank is empty and, above said caisson, an upper operating end and detachable means for detachably anchoring the lower ends of said pillars on said bottom, means for lifting the empty tank which comprise a series of catenary suspension systems equal in number to said pairs of pulleys, each of said catenary suspension systems comprising a carrier cable mounted on two diametrally opposite pulleys of a pair of pulleys and extending diametrally through said circular aperture of said cylindrical wall and a series of slings suspended at spaced intervals along said carrier cable, said slings of said catenary suspension systems being anchored on the upper ends of said pillars and the lower ends of said pillars being anchored on said tank bottom, and a series of hydraulic jacks mounted on the ground about said cylindrical wall for exerting an upward thrust on said brackets secured around said cylindrical Wall, whereby when said catenary suspension systems are tensioned said circular caisson and said bottom are stiffened in relation to the cylindrical Wall and the actuation of said jacks causes the thus stiffened assembly to be lifted bodily.

2. For a liquid storage tank comprising a circular bottom bearing on the ground, a cylindrical wall extending vertically about said circular bottom and ending at its top with a circular edge defining a circular aperture, at least one peripheral reinforcing ring secured around said cylindrical wall, a series of brackets carried by said periph eral ring, a stiffening ring structure secured about said circular edge of said cylindrical wall, a series of frames regularly spaced about said stiffening ring structure to constitute pairs of diametrally opposite frames, a series of pulley mounted to form pairs of diametrally opposite pulleys on said frames, a concrete ring formed in the ground around said cylindrical wall and beneath said brackets, a caisson having a cylindrical contour which is fitted in sliding and sealing engagement in said cylindrical wall to constitute a floating roof structure on the liquid to be stocked in said tank, a series of vertical pillars extending through and rigid with said caisson, each of said pillars having beneath said caisson a lower end hearing on said bottom for supporting said caisson thereon when said tank is empty and, above said caisson, an upper operating end and detachable means for anchoring said lower pillar ends to said bottom, means for lifting the empty tank which comprise a series of catenary suspension systems equal in number to said pairs of pulleys, each of said catenary suspension systems comprising a carrier cable mounted on a pair of diametrally opposite pulleys of a pair of pulleys and extending diametrally through said circular aperture of said cylindrical wall and a series of suspension slings disposed at spaced intervals along said carrier cable, said slings of said catenary suspension systems being anchored on the upper operating ends of said pillars and said lower ends of said pillars being anchored to the bottom of said tank, and a series of hydraulic jacks mounted on said concrete ring around said cylindrical wall for exerting an upward thrust on said brackets secured around said cylindrical wall, whereby when said catenary suspension systems are tensioned said circular caisson and said bottom are stiffened in relation to said cylindrical wall, and the operation of said bydraulic jacks causes the thus stiffened tank assembly to be lifted bodily.

3. A tank for utilizing the lifting means set forth in claim 2, wherein a ring-shaped member in which two diametrally opposite holes are formed is secured in the bottom beneath each pillar, each pillar consisting of a telescopic assembly comprising an external tubular member extending through and rigid with said caisson, carrying beneath said caisson a bearing flange adapted to engage said ring-shaped member and being formed beneath said caisson and said flange with two diametrally opposite holes aligned with the holes formed in said ring-shaped member, and, above said caisson, with a series of diametrally opposite holes, an inner tubular rod housed in said external tubular member and having an upper operating end carrying a ring for anchoring a sling from the catenary suspension system and formed beneath said anchoring ring with a stepped series of pairs of diametrally opposite holes, pins for mounting said telescopic assembly which are engageable in the pairs of holes extending through said external tubular member above said caisson and also in pairs of holes, properly selected according to the desired length of the telescopic pillar, of the inner tubular rod, the detachable means for anchoring the lower end of each pillar to the bottom of the tank consisting of a pin engaging a pair of diametrally opposite holes of said ring-shaped member and a pair of diametrally opposite holes formed in said external tubular member beneath said bearing flange.

No references cited.

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