US2847142A - Floatable partition for liquid storage tanks - Google Patents

Description

Aug. 12, 1958 J. H. MQCLINTOCK ETAL I 2,847,142

FLOATABLE PARTITION FOR LIQUID STORAGE TANKS Filed July 8, 1954 3 Sheets-Sheet 1 Rob t w Mam, Jr. lnventors y Attorney FLOATABLE PARTITION FOR LI QUID STORAGE TANKS Filed July 8, 1954 3 Sheets-Sheet 2 John H. McClintock Rob t w Manz JR Inventors MW Attorney 1958 J. H. M CLINTOCK nu. 2,847,142

LIQUID STORAGE TANKS FLOATABLE PARTITION FOR Filed July 8, 1954 3 Sheets-Sheet 3 .m 2 I: w 2 2 b- E |0| 9 W3 n I:

FIG-3 .w W I I Q 6 {3 G... F

Attorney United States Patent 2,847,142 'FLOATA'BLE PARTITION FOR LIQUID STORAGE TANKS John H. McClintock, Cranford, and Robert W. Martz, Jr., opatcong, N. J., assignors to Esso Research and Engineering Company, a corporation of'Delaware Application July 8, 1954,;Serial No. 442,170 13 Claims. (Cl. 220-26) produced by 2,847,142 Patented Aug. 12, 1958 Qihce tank as shown in Fig. 1, taken along the line Fig. 1; 1

gas into the vapor space above .spaced arcuately shaped angle iron reinforcing members Fig. 3 is an enlarged view in vertical section of a portion of and of an inflatable cover according between the cover and tank wall as indicated in Figs 1 and Fig. 4 is a view similar to that of Fig. 1, taken along the line IV-IV of Fig. 5, illustrating another form of and also for introducing inflation the cover;

ig. 5 is a view in horizontal section through a storage tank as shown in Fig. 4, taken along the line V.V of Fig. 4;

such as designated in Fig. 3

cone shaped roof 13, including a hatchway or manhole 14 opening through the roof.

floor portion 22 is formed of three sheets disposedwith are cemented together, and the o as spaced relation to the tank axis x--x, and the center point of the partition, and at such distance from the axis as to be substantially alignable vertically with reference to the roof hatchway 14. The hatch cover 25 is provided with spring hinges 25a, and may be opened by means of a cable attachment 25b.

The annular pontoon element 21 has an outside di ameter somewhat smaller than the internal diameter of the tank at the wall, and also less than that at the innermost edge of the angular reinforcing members 12. For

example, in a tank having an internal diameter of about feet 4 inches and with reinforcing members extending horizontally from the wall into the storage space for a distance of about 3 inches, the pontoon element 21 might have an outside diameter of about 9 feet 2 inches. With such dimensions the diameter of pontoon would be about 8 inches less than diameter of the tank at the inner edge of the reinforcing members 12, and about 14 inches less than the diameter of the tank from wall to wall. Thus when centered on the tank axis, the pontoon could be freely and buoyantly supported on the uppper surface of the liquid contents of the tank so as to be reciprocally movable vertically in substantially right angular relation to the vertical axis of the tank.

To center the pontoon element in the tank and to provide a substantialy fluid-tight seal between the pontoon and tank walls, the outer periphery of the pontoon carries annular sealing means 2.6 extended radially outward therefrom into frictional contact with the tank walls. As shown in Figs. 1, 2 and 3 of the drawings, the centering and sealing means is a laminated means composed of a vertical series of annular elements each formed of a flexible, deformable material similar to that of the pontoon 21, and membrane 22. In the form shown the number of elements is odd, including a mid-element 27, and successive pairs of elements such as designated by the numerals 28a and 23b, and 29a and 2%, wherein the mid-element has a radial dimension outwardly from the outer periphery of the pontoon which is greater than one-half the difference between the outer diameter of the pontoon and the inner diameter of the tank, and in succeeding pairs the radial dimension of each element is equal to that of the other in that pair but less than that of the mid-element, and wherein from pair to pair the radial dimension of the elements diminishes from pair to pair. In Fig. 3 the paired elements and their relationships to each other and to the mid-element are clearly shown, with one element of each pair disposed above and one below the mid-element in the series. Further, although all the elements 27, 2&1, 28b, 29a and 2% are each shown as of a single thickness substantially equal to that of the pontoon and membrane material, these individual elements may be made thinner or thicker as desired and individually also may be laminated. The primary requirement in any event is that they provide a flexible sealing means between the pontoon 21 and tank wall 1 which means is deformable as required to ride over any protruding part of the wall surface, such as angles 12, and yet to provide adequate resistance to hori zontal displacement of the floating partition such as to maintain the partition substantially centered on the vertical axis of the tank. Also, although the sealing means may be made to be substantially self-supporting by suitable selection and gradation of the thickness of the laminae, principally the paired elements, it is preferred that they be provided with supplementary annular stiffening means such as the elements 3t and 31. These elements are preferably of a substantially rigid material such as metal or hard rubber, plastic, or other similar materials with or without integral metal reinforcement. Any suitable means may be employed to secure the elements 30 and 31 to the outer surface of the pontoon, or, as shown, to the surface of the sealing means as attached to the pontoon. Further, in the assembled sealing means shown, the surfaces of the several laminae are cemented together at their inner edges within the outer periphery of the elements 31 and 31, and also to the inner opposed surfaces of these elements, and may be further secured as by means of rivets 31c extending through the elements 30 and 31 as shown. Beyond .the outer edge of the elements 30 and 31, the elements 27, 28a, 23b, 29a, and 2% are in free surface contact. Alternately, however, these elements may be cemented together from their roots at the pontoon outer periphery to their outer edges. The annular elements 27, 2%, 23b, 29a, 29b, 39, and 31 may also consist of a plurality of arcuate sections arranged in either overlapping or butt joint relation with the joints of one element in circumferentially staggered relation to those of another.

In addition to the peripheral sealing means and floor closure, escribed above, the pontoon element as shown is provided with means for inflating and deflating the pontoon, and also supplementary means for retaining the assembly against rotational movement within the tank. In the drawings, the inflation and deflation means is a valve 32, such as a tire valve, opening through the material of the pontoon. As later described this means may include semi-permanent conduit connections nal source of fluid under pressure, or may include a pressurized fluid container mounted on the pontoon. Also, where desired, the pontoon may be divided internally into a series of fluid-tight compartments with individual valve means for each compartmel t Various retainer means may also be provided. A simple form is illustrated, consisting of a pair of guy ropes 35 attached to the pontoon surface at opposite ends of a chordal dimen sion which is less than the diameter of the pontoon at the level of attachment. Where the change in level of the liquid contents is infrequent, the guy ropes may be belayed on any suitable cleat within the hatchway 14; otherwise a spring actuated tension reel may be employed.

An alternate form of the invention is illustrated in Figs. 4, 5 and 6. In these figures corresponding parts are designated by numerals corresponding to those employed in the description of Figs. 1, 2 and 3. Thus, the numeral 111 designates a tank, 112 angular, annular reinforcing members, 113 a tank roof, and 114 a hatchway. The numeral 115 designates a body of liquid in the tank with a vapor space 116 above it. The numeral 121 designates a pontoon member which differs from that shown in Figs. 1, 2 and 3, in being provided with a series of radial spoke elements such as 121a, 121b, and 1210. These elements are hollow tubular members communieating at their outer ends with the main pontoon member 121. Preferably the inner or hub ends of the spoke elements are sealed one from another, and the pontoon member divided into three compartments by means of fluid-tight partitions, indicated by dotted lines in Fig. 5, and designated by the numeral 121d, disposed internally and transversely of the tubular pontoon, intermediate the communicating attachment of the spokes with the pontoon. The enclosed area of the annular pontoon 121 is closed by means of a membrane closure or floor portion 122 attached to the pontoon 121 substantially as is the membrane 22 to pontoon 21 of Figs. 1, 2 and 3. The membrane 122 may also be attached to the spoke elements in a similar fashion. A hatchway 124 and batch cover 125 with spring hinges 125a and cable attachment 12% all correspond to their previously described counterparts 24, 25, 25a and 25b, and are similarly located with reference to the vertical axis xt, of the tank 111 in Figs. 4, 5 and 6.

In the apparatus illustrated by the latter figures, the annular sealing and centering means is provided by a vertical series of annular fin elements, 127, 128:: and 128b, each secured at its inner periphery to the outer periphery of the pontoon 121 similarly to the elements 27, 28a and 28b previously described. In the form now contemplated, the elements 127, 128a and 12812 are vertically spaced, and each element extends radially outward to an exterfrom the pontoon into frictional,

theinner wall.

interior of the spoke elements 'height of the tank.

' Most desirably 'the assembly .slidable contact with referably the spacing of vtheilayered elements is such as'to'permit at least two elements, toremain in sealing contact with the wall of the tank while a third element may be deformed by passage over an obstruction or projection thereon. n Fig. 6, the element 127 is shown to be.deformed by the angle reinforcement member 112, while the elements 128a and W128]) are in sealing contact with the tank wall. Also as .illustrated, the individualelements 127, .128aand '128b are thickerthan the previously described elements 27, 23a andf28b, 'soas tobe substantiallyself-supporting. The

' elements127, 128a and 12812, howevenalso may be pro- In the preferred form of the apparatus referred to, wherein the spoke elements are sealed one from another, separate means for inflating the pontoon compartments are provided. In Figs. 4, 5 and 6 such means include three valve elements 132a, 132b, and 1320 open into the 121a, 1211: and 1210, reare connected to a comflexible conduit 134 conspectively. All of these valves end of a rigid conduit 135 supported on thetank roof and wall. The other end of the conduit 135 is connected to a suitable source (not shown) of a gaseous material under pressure. 'The flexible conduitprovided is of a length substantially equal to the If desired, the'flexible conduit may bemounted .on an automatic, springoperated take-up age from the pontoon may be readily discovered from Anotherfeature of the form of floatable partition, as illustrated in Figs. 4, 5 and 6 resides in-theprovision of means for discharging the, gas used to inflate the pontoon member into the vapor space of the tank. Such means is afforded by a plurality of pressure relief valves and"111'by,insertion through an opening or hatchway such as designated by the numerals 14 and 114. Where conduit means such .as 134 and 135 of Figs. 4, 5 and 6 are to be used, in folding the assembly the valves 132a,

132b, andl32c are preferably left exposed so thatthe flexible conduit hand. Likewise 134 may be connected thereto beforein folding or rolling the assembly as illustrated in ,Figsl, 2 and 3, it is desirable that the :valve '32 be available for connection with a detachable pressure conduit means. ,Of course if the pontoon is provided wi'th automatic self-containedinflation means,

no special-rolling or folding technique need be employed. will be introduced into the tank at a time when the liquid surface is at .an intermeof ;said pontoon 'terial secured at its diate level in the tank, and preferably when the .tank is atileast half'full, in, orderto facilitatemanipulation during or after insertion.

After inserting the assembly through the hatchwayor opening in the tank the foldsmay be shakensout and while held as by the restraining ropes or cables 33 or 133, the pontoon member is at least partially inflated. The assembly may then be dropped onto the liquid surface and its position adjusted so as to bring the ' hatcht 24 or 124 into alignment with the hatch 14 or 114 as illustrated and described,fbefore complete inflation of-the pontoon member forces the sealing meansinto complete pressure contact With the tank Walls. .When'in position, the inflation ofthe pontoon member is completed and the assembly is then in service.

in fabricating therassembly, the displacement thereof is gauged so that the membrane closure element or floor portion 22 or 122 is assured of intimate'surface contact With-the liquid over substantially its entire area. displacementis also gauged so that. displaced liquid will level high enough to make contact with the sealing means under any normal operating condition.

'terial, an annular seal ring ofsa flexible, deformable material secured at its inner periphery to the outer periphery element, .in fluid-tight relation thereto and extending radially outward therefrom, a substantially hollow, a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a'flexible, deformable mainner periphery to the outer periphradially outward therefrom, said..annular seal ring including a plurality of individual, annular elements disposed in. parallel, superposed relation, of which each element is secured at its inner periphery to the outer peripheral surface of said pontoonelement, asub- 'stantially flat membrance of a flexible, deformable-material joined to the outer surface of said pontoon. element in substantially fluid-tight, tangential relation .thereto, and forming a floor for said pontoon extending overr-the entirearea enclosed thereby, and valve means communieating With theinterior of said pontoon element adapted to permit inflation and deflation of said pontoon element.

3. A collapsible floating roof assembly comprising a tubular, annular, continuous pontoon element of a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a flexible, deformable materialsecured in its inner periphery tothe outer periphcry of said pontoon element, in fluid-tight relation therements increasing in equal pairs inwardly from the pair of elements forming the upper and lower surfaces of said seal ring, and wherein said odd member of said elements is the middle member and has an outer diameter greater than any other member, a substantially flat membrane of a flexible, deformable material joined to the outer surface of said pontoon element in substantially fluidtight, tangential relation thereto, and forming a floor for said pontoon extending over the entire area enclosed thereby, and valve means communicating with the interior of said pontoon element adapted to permit inflation of said pontoon element.

4. A collapsible floating roof assembly comprising a hollow, tubular, annular, continuous pontoon element of a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a flexible, deformable material secured in its inner periphery to the outer periphery of said pontoon element in fluid-tight relation thereto and extended radially outward therefrom, said annular seal ring including a plurality of individual, annular elements disposed in parallel, superposed relation, of which each element is secured at its inner periphery to the outer peripheral surface of said pontoon element, a pair of annular support elements secured at their inner peripheries to the outer periphery of said pontoon element, the elements of said pair being disposed respectively above and below said annular seal ring in surface contact therewith, said support elements having an outer diameter smaller than that of any of said individual, annular seal ring elements, a substantially flat membrane of a flexible, deformable material joined to the outer surface of said pontoon element in substantially fluid-tight, tangential relation thereto, and forming a floor for said pontoon extending over the entire area thereby, and valve means communicating with the interior of said pontoon element adapted to permit inflation and deflation of said pontoon element.

5. A collapsible floating roof assembly comprising a hollow, tubular, annular, continuous pontoon element of a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a flexible, deformable material secured at its inner periphery to the outer periphery of said pontoon element in fluid-tight relation thereto and extended radially outward therefrom, said annular seal ring including a nular elements disposed in parallel, superposed relation, of which each element is secured at its inner periphery to the outer peripheral surface of said pontoon element, a pair of annular semi-rigid support elements of a heavy gauge material similar to that of said annular seal ring secured at their inner peripheries to the outer peripheral surface of said pontoon, the elements of said pair being disposed respectively above and below said annular seal ring in surface contact therewith, said supportelements having an outer diameter smaller than that of any said individual, annular seal ring elements, a substantially flat membrane of a flexible, deformable material joined to the outer surface of said pontoon element in substantially fluid-tight, tangential relation thereto, and forming a floor for said pontoon extending over the entire area enclosed thereby, and valve means communicating with the interior of said pontoon element adapted to permit inflation and deflection of said pontoon element.

6. A collapsible floating roof assembly comprising a hollow, tubular, annular, continuous pontoon element of a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a flexible, deformable material secured at its inner periphery to the outer periphery of said pontoon element, in fluid-tight relation thereto and extending radially outward therefrom, a flat membrane of a flexible, deformable material joined to the outer surface of said pontoon element in substantially fluid-tight tangential relation thereto, and forming a floor for said pontoon extending over the entire area enclosed thereby, valve means communicating with plurality of individual, an-

substantially Y the interior of said pontoon element adapted to permit inflation and deflation of said pontoon element, a series of hollow, tubular, spoke-like flotation elements, formed of said substantially fluid-impervious, flexible, deformable material, disposed radially with relation to said pontoon element, each of said spoke-like flotation elements secured at its outer end to the inner peripheral surface of said pontoon element and in substantially open communication therewith.

7. A collapsible floating roof assembly comprising a hollow, tubular, annular, continuous pontoon element of a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a flexible, deformable material secured at its inner periphery to the outer periphery of said pontoon element, in fluid-tight relation thereto and extending radially outward therefrom, a substantially flat membrane of a flexible, deformable material joined to the outer surface of said pontoon element in substantially fluid-tight tangential relation thereto, and forming a floor for said pontoon extending over the entire area enclosed thereby, valve means communicating with the interior of said pontoon element adapted to permit inflation and deflation of said pontoon element, a series of hollow, tubular, spoke-like flotation elements formed of said substantially fluid-impervious, flexible, deformable material, disposed radially with relation to said pontoon element, each of said spoke-like flotation elements secured at its outer end to the inner peripheral surface of said pontoon element, in substantially open communication therewith, and in substantially tangential surface contact with said membrane.

8. A collapsible floating roof assembly comprising a hollow, tubular, annular, continuous pontoon element of a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a flexible, deformable material secured at its inner periphery to the outer periphery of said pontoon element, in fluid-tight relation thereto and extending radially outward therefrom, a substantially flat membrane of a flexible, deformable material joined to the outer surface of said pontoon element in substantially fluid-tight tangential relation thereto, and forming a floor for said pontoon extending over the entire area enclosed thereby, a series of hollow, tubular, spoke-like flotation elements, formed of said substantially fluid-impervious, flexible, deformable material, dis posed radially with relation to said pontoon element, each of said spoke-like flotation elements secured at its outer end to the inner peripheral surface of said pontoon elements in substantially open communication therewith, a

series of vertical partitions each disposed internally of said pontoon element in fluid-tight relation thereto intermediate the outer ends of an adjacent pair of said flotation elements, said flotation elements each having a sealed junction with said other flotation elements at their inner ends and an individual valve means opening through the wall of each flotation element into communication with the interior of said pontoon element through said flotation element.

9. A collapsible floating roof assembly comprising a hollow, tubular, annular, continuous pontoon element of a substantially fluid-impervious, flexible, deformable material, an annular seal ring of a flexible, deformable material secured in its inner periphery to the outer periphery of said pontoon element in fluid-tight relation thereto and extended radially outward therefrom, said annular seal ring including a vertical series of individual annular elements disposed in vertically spaced parallel relation peripherally of said continuous pontoon element each of said annular elements being attached at its inner edge in fluid-tight relation to said pontoon element, a substantially flat membrane of a flexible, deformable material joined to the outer surface of said pontoon element in substantially fluid-tight tangential relation thereto, and forming a floor for said pontoon extending over the entire area enclosed thereby, and valve means com- 10. I -.a rigid roofsupported on said municating with the .intei'ior pf said pontoon :element adapted. to penniti inflation and deflation. of. said pontoon element.

n a storagetank havingsubstantially verticalwalls,

substantially fluid-impervious,.lfiexible, deformable material having. an outer. diameter. less than. the. innerdiamof a substantially fluid-impervious .fiexible defonnable ismaterial joined'in fl'uid-tight relation-Jo the=uter surface of said pontoon element sosasnto center of said area and the outer ends extending outward to a ing .a hollow,

ment of a substantially fluid-impervious, flexible, .de-

formable material having .an .outer diameter less than in said liquid when an annular seal ring of a flexible, deformable material having an inner diameter substantially equal to the outer diameter of said pontoon element attached at its inner periphery in fluid-tight relation to the outer periphery of said pontoon element, said ring extending radially outward from said pontoon element into frictional, pressure engagement with the inner wall of said tank, said ring having an outer diameter slightly greater than the inner diameter of said tank, a substantially flat membrane of a substantially fluid-impervious, flexible, deformable material joined in fluid-tight relation to the outer surface of said pontoon element so as to extend over the entire area enclosed by said pontoon element and forming a floor adapted to be disposed in intimate surface contact with the body of liquid contained by said tank, a series of vertical partitions internally of said pontoon element disposed in fluid-tight relation thereto and at regular spaced intervals therein to divide the interior thereof into a series of separate compartments of substantially equal volume, a plurality of hollow, tubular flotation elements, each formed of said substantially fluid-impervious, flexible, deformable material and equal in number to the number of said compartments, each of said flotation elements having an inner and an outer end and disposed radially of the area enclosed by said pontoon element with the inner ends of said flotation elements joined in fluid-tight, non-communicating relation substantially at the center of said area and the outer ends extending outward to a fluid-tight juncture with the inner peripheral surface of said pontoon element, said flotation elements each communicating at itsouter end with a separate compartment of said series of compartments, individual valve means opening into the interior of each said flotadisposed Within said tank connected at one end in fluidtight communication With the inner end of said rigid conduit and at the other end extended into fluid-tight communication with each of said valves opening into the interiors of said flotation elements, pressure relief valve means opening from each of said series of separate compartments in means connected in said rigid conduit adapted to said pontoon element, and control valve regulate fluid flow through said rigid and flexible conduits, and pressure in said pontoon element.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain June 24, 1938

Images