US2329967A

US2329967A - Supporting structure for floating tank roofs

Info

Publication number: US2329967A
Application number: US430532A
Authority: US
Inventors: John H Wiggins
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-02-12
Filing date: 1942-02-12
Publication date: 1943-09-21
Anticipated expiration: 1960-09-21

Description

Sept. 21, 1943. J. H. WlGGlNS SUPPORTING STRUCTURE FOR FLOATING TANK ROOFS Filed Feb. 12, 1942 Patented Sept. 21, 1943 SUPPORTING sTRUoTUnEjFoR FLQATING f A KROQFS 3 John H. Wiggins, Chicago, in; Application February 12,1942, Serial red-430,532;

2 Claims. ((1220-26) This invention relates to liquid containers of the. type that are equipped with a floating roof, and particularly, to the means used in such structures for supporting or sustaining the weight of the roof when the roof is not floating on liquid in the container. I

One object of my invention is to provide an improved auxiliary supporting structure for a float ing roof, which is of such design that when cleaning of the container becomes necessary,said auxiliary' supporting structure can be adjusted or manipulated so as to cause the roof to be. sustained at a level high enough above the bottom of the container to provide ample clearance .for workmenengaged in the operation of removing sediment that has collected on the bottom of the container.

Another object is to provide a supporting means fora floating tank roof, that has provision for sustaining the roof in either one of two different levels when the tank is empty, or substantially empty, and which can beproperly adjusted or manipulated while the roof is floating on liquid in the tank, so as to select the particular level at which it is desired to support the roof, when. the liquid is discharged from the tank.

Andstill another object of my invention is to provide a floating tank'roof that is equipped with a plurality of horizontally-slidable, auxiliary supports-that are mounted on theroof in such away that they are'operable from the top side of the roof, but nevertheless, are hidden from view and protected from the weather. Other objects and desirable features of my invention will be here: inafter pointed out.

Figure 1 of the drawing is a vertical transverse sectional view of a pontoon type floating roof constructed in accordance with my present invention, showing the roof floating on liquid in the container, and illustrating the horizontallyslidable, auxiliary supports arranged in their in-' active position.

Figure 2 is a similar view, showing the roo floating on the liquid, and illustrating the auxiliary supports in their active position.

Figure 3 is a vertical, transverse sectional view, illustrating how said horiZontally-slid'able, auniliary upports co-act with thefixed or stationary supporting structure insideof the container to maintain the root high enough above the bottom of the container to provide ample head room or clearance for workmen engaged in the operation of cleaning the container; and 1 Figure' i is an emarged'sectional v 'w, taken on the line 45-4 ofFigureZ, looking in the direction indicated by the arrows. u I l Inthe accompanying drawing which illustrates the preferred formbf my invention, A designatesa liquid container, such as an oil storage tank, and Bdesignates .asanentirety a floating roof which normallyv 'floats upon liquid :1: in the tank, said roof comprising; a limber metal deck [that is attached to the upper end of, an annular pontoon c locatedat the periphery of the roof.

My invention consists of a supporting means.

. for the roof B, which isof such construction that it will sustainthe roof at either one of two difierent levels when the tank is empty orinot filled with sufiicient-liquidlto float the roof. I One of said levels constitutes the lowermost position of the roof, and the. other level constitutes the position of the roof when the bottom of the tank is being cleanedto remove sediment that has collected'thereom Preferably, the roof is sustained inits lowermost pjosition,or atlthe low level, by a fixed or stationary supporting structure D in the lower portion of .the tank A, disposed so thatthe pontoon C of the roof willcometo rest thereon when the level of the liquid in the tank drops to a point below the top surfaceof said support-' ing structure ll-lilhe particular construction of the supporting structure D is immaterial. It'mayconsist of short standards oruprights that project upwardly from thebottom of the tank A in proximity to the side wall of the ;tank,or' it may,

consist of a framework on the bottom ofthe tank that extends circumferentially around the tank adjacent the tank side wall. The roof is sustained at the high level or in tank cleaning position, by

aplurality of horizontally-slidable, auxiliary supports E on the, roof, that areadaptedto beshifted into a .positionwherein they co -act with the fixed. or stationary supporting structure D, to in effectincrease the height of same, or in other words,

form upwardly-projecting extensions on the stationary supporting structure D,'on which the pontoon of the roof comes to'rest, during the operation of emptying the tank, thereby causing the roof tobe supported highenough above the bottomof the tank to proyide ample head room for workmen engaged in cleaning the tank.

The horizonta1lys1idable,- auxiliary supports E .canbe mounted on the roof B' invarious ways without departing from thesp-irit of my invention, but I prefer to suspendthem from theunderside of the roof in such'amannerthat-they are operable from the top side of the-rooi when r the roof is floating, and can be easily shifted from a normally inactive position into an active position, wherein they are disposed underneath the pontoon C of the roof. When the auxiliary supports E are in their inactive position, shown in Figure 1, they are disposed out of vertical alignment with the pontoon C of the roof and the fixed or stationary supporting structure D inside of the tank, and accordingly, do not interfere with the rise and fall of the roof, in response to variations in the level of the liquid :0 on which the rooffloats. 'Also,'-wh'en the level of theliquid drops to such -'a point that the pontoon of the roof moves downwardly onto the fixed or stationary supporting structure D, the auxiliary supports E do not interfere with the downward movement of the roof, due, of corirsetb'thefact that said auxiliary supports E lie in a different vertical plane than the plane in which the po'ntoon C and stationary supporting struoture D are disposed. When it becomes necessary to remove sediment that has collected on'tlie-iiottom of the tank A, the auxiliary supports E are shifted "horizontally intoth'eir active' position. L as shown in Figure 2. Subsequently, when "the liquid "as is discharged from the tank "to; empty the tank, the "roof jjmoves "downwardly until the auxiliary supports E come in contact with the stationary supponting'structure D, thereby eansing'the root to be suppofted' or sustained'at'a'level high enough above 'thebottomof the'tank, as shown in Figure 3, tofprovi'dehmple fhead room or clearance forjthe 'w orkm en engaged in "the operation rifeleaningfthetank. I

In theform'of my invention herein illustrated, each of the auxiliary supportsE is suspended froin'a l'iorizontally disposed cafrrien'Z that slides in'bearings on the underside offthe roof. 'In'ofrd'er thatthe aui'ril-ia'ry supports E may he readily mevea into an'lr out (if their active "position, while the 'roof fis-iioating on rthe' liquid inthe' tank, the carriers 2 we slidin'giy mounted in'bearihg' 3 carrid 'by the inner vertical wall oi the pontoon c and bearin 's S that'project downwardly from the underside of the 'd'eok l of the roof in spaced relationship with-the bearings-"3 fan d the pontoon CKis pr'oViHed in its top-'wallwithmanhol'es 4* that are-normally closed by iemovable manhole "covers 5 theearriers 2 'being so arrangedth'at they can be nianipiilate'dfrom theihterior-o'f the pontoon to 'shift the supports E horizontally into and'o'ut of "their ac'tivefpo sition. V H

Ealch 6f the horizontally reciprocatingcarriers 2 as provided with a'dependlng rod or i-eg e to which-one or theauxiliarysupports n is attaeheii, land-said auxiliary supports'are prferablyioi'med from 'hgillow members that have "some buoyancy, as I have found tl1'at*this type or construction is desirable, inasmuch the buoyan't auxinar supports E exert little or no load on the reipr o cating tia rriers 2, and accordingly, do not retard vetti'cal alignment with the pontobnQ'theupper 75 ends of said auxiliary supports will be spaced slightly away from the bottom of the pontoon C,

as shown in Figure 2. Subsequently, when the roof moves downwardly, the rods or bars 6 will flex sufiiciently to permit the bottom of the pontoon to contact with the upper end of the auxiliary supports E, and thus cause the weight of the roof .to be transmitted directly to the fixed or stationary supporting means D by the auxiliary supportsE. In order to prevent gases from escaping-from the gas spaceof *the-tank'through the bearings 3 in the inner side wall of the pontoon C, said bearings 3 are provided with removable closures 1 which normally are mounted on or combined'withsaid bearings 3 in such a way as toclose the openings in the side wall of the ponto'on through which the carriers 2 project into the interior of the .pontoon.

'Fromthe foregoing it will be understood that the 'auxiliary supports E are normally set or adjusted in the position shown in Figure 1. -At such times the fixed or stationary supporting structure D inthetank sustains the weight of theroof wheneverthelevel of th'eliquid :0 drops low enough to causethe pontoon of the roof to rest upon'said supporting structure I). If cleaning of the tank becomes necessary, the manhole covers 5 of the pontoon are removed, as shown i'n'Figure2, so a'stolpemnitthe closures 1 of the hearings 3 to be'taken'off, after which the carriersZ-aifemoveil in a direction to'shift the auxiliary'sup'ports 'E into operative relationship with the -ponto'on to cause the roof to be [sustained at {a level considerably higher than the level at whichtherodflies whenthe pontoon of the roof r'ests directly upon the stationary supporting structure D. Whenth'e roof 'isin this position, ample clearance or head room is provided'for'the workmen inside of 'the tank who are engaged in thehfperationof-cleaning "thetank. At the e'oinpl'tionof the cleaningoperation, liquid is again admitted'rtothe tarik, and after the liquid level has become high enough to *float' the roof, the auxiliary supports E are slid horizontally backto their inactive position-and theclosures 1 are-replaced cn the liearirigstin the side wall of the pontoon.

"Qne "decided aevantagedr a tank roof supporting 3: structure of the kind above eesqnbee, is

that the ope'rator whoadjusts' or mamb iatesn is notapt to make a 'hiistake and'set the auxiliary supports in their "finactive position. whenhe intended that sai'disupports should be' set in their 'adtiii 13051131011. ThiSdS hCaLliSB "Said auxiliary 1 supports are fastened to horizontally-slid'abie carriers that are mounted on "the rodf in such ainan'ner that-when the operato'rpulls said carriers towartlshi'rh,'orfinothe'r words, slides said carriei s outwardly tOwar dSthe sidewall (if the I tank, he"-1 nows'that theauxiliary supports will move intotheir a'ctive position in vertical alignment with thepontoonofthe'roof, "and 'whe'n' he pushes said carriers away from himfor pushes them inwardly towards the center of the tank, he knows that the auxiliary supports will be shifted out of the zoneof -the pontoon-into their inactive position.

Another desirable feature or characteristic of my improved construction, is that it does not rely on gravity .or .on a separate stop block attached to the roof, to determine or control the active'pos'ition o'f the auxiliary support. It is the inner side wall or rim of the potoon that governs the active position of the auxiliary supports, and said supports are fastened to horizontally-slidable carriers, which are of such cross-sectional shape, that they cannot twist or turn, and thus cause the auxiliary supports to assume an improper position. In addition to the above mentioned desirable characteristics, my improved construction is of rugged design, it is easy to install, and the auxiliary supports are hidden from view and well protected from the weather.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

toon and said pontoon being provided with means that provides access to said carriers.

2. The combination of a liquid container, a

floating roof in said container provided at its periphery with a dependingv pontoon, stationary supportingmeans for sustaining the roof in comparatively close proximity to the bottom of the container when the roof is' not floating, and horizontally-slidable, auxiliary supports on the underside of the roof, normally spaced away from the inner edge portion of the pontoon of the roof but adapted to be moved under the inner edge portion of said pontoon to co-operate with same and with said stationary supporting means, to

sustain the roof at a higher level than the level at which the roof lies when it is sustained by said stationary supporting means, said auxiliary supports being suspended from horizontallyreciprocating carriers on the underside of the roof that slide in-bearings in the side wall of said pontoon.

JOHN H. WIGGINS.