US2007193A - Floating deck for oil storage tanks - Google Patents

Description

July 9, 1935. A. M. GRIFFIN FLOATING v.DECK FOR OIL STORAGE TANKS Filed Dec. 5, 1932 5 Sheets-Sheet l Invenlor.' A/vh M Griffin;

ltorney July 9, 1935. A, M. GRIFFIN 2,007,193

FLOATING DECK FOR OIL STORAGE TANKS Filed Deo. 5, 1952 5 sheets-sheet 2 Alva/Z1 M. Griffin;

Attorney Inventor;

July 9, 1935. A. M. GRIFFIN FLOATING DECK FOR OIL STORAGE TANKS 5 Sheets-Sheet 5 Filed Deo. 5, 1932 I wen tor; Alvah ZM'.4 Griffin;

A Homey July 9, 1935. A. M. GRIFFIN FLOATING DECK FORVOIL STORAGE TANKS Filed Deo. 5, 1952 5 Sheets-Sheet 4 YIIIIIJIII Inventar. Alva/Zz M. Griffin;

Attorney July 9, 1935. A. M. GRIFFIN FLOATING DECK FOR OIL STORAGE TANKS Filed Dec. 5, 1952 5 Sheets-Sheet 5 Inventor.' Alva/h M Griffin/I' Patented July 9, 1935V UNITED STATES FLoATING DECK Fon. on. s'roRAGE TANKS Alvah M. Griffin,

Los Angeles, Calif.

Application December 5, 1332, Serial No. 645,654

4 Claims.

This invention contemplates the provision of an improved type of iloating deck for oil storage tanks for the prevention of iire and excessive evaporation, andincludes as salient objects the provision of a tank having a structure fabricated in a novel manner composed of a plurality of sections peculiarly fitted and secured together; the provision of an improved type of gas trap, one or more of which is provided in the deck for the purpose of releasing the volatile gases and separating the fluid elements therefrom; means within the tank and adjustable relative to the deck capable of manual operation for disposition at a selected elevation whereby the oil may be discharged fromthe tank and automatically operable when the deck is lowered to a predetermined extent for discontinuing the flow of the oil from the tank; and the provision of an improved type of seal circumferentially arranged around the floating deck and engaging the wall of the tank.

Other and more detailed objects of invention may appear as the description progresses.

In the accompanying drawings I have shown a preferred form of structure embodying my invention, in which Fig. 1 is a top plan View of an oil storage tank with my improved floating deck operatively mounted therein.

Fig. 2 is an enlarged transverse section of one of the sections of the deck on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary section of the same showing a hand hole and cover therefor typical of each of the sections of the deck.

Fig. 4 is an enlarged top plan view of one of the sections together with portions of adjacent sections and including a trap for separating and releasing the gas from the oil in the tank.

Fig. 5 is an enlarged section of the same on line 5-5 of Fig. 4 showing details of the trap.

Figs. 6 and 7 are, respectively, similar sectional elevations of the oil tank and deck shown in Fig. l with the deck disposed at different elevations in the tank corresponding to the level of the oil therein.

Figs. 8 and 9 are, respectively, a side elevation and a diagrammatic elevation at right angles to Fig. 8, showing means for operating and for operatively supportingan oil discharge means in the tank associated with the floating deck.

Fig. l is a top plan view of one of the deck sections showing structural details thereof.

Fig. 11 is a fragmentary sectional elevation of the two adjacent sections of the deck showing the manner of attaching said sections together.

Fig. 12 is a fragmentary plan of the same.

Fig. 13 is a view of a sheet of metal cut to form one of the deck sections.

Figs. 14 and 15 are, respectively, a fragmentary plan and an elevation of the flexible self-adjusting seal circumferentially secured to the oating deck for engagement with the wall of the tank.

As generally arranged, my improved deck is adapted to be operatively positioned in a circular Atank T which is usually provided with a wind girder G therearound. The deck D is preferably composed of a plurality of sections I, l etc., of rectangular form, each of which is formed of sheet metal comprising a bottom 2 with marginal portions 3, 3, as shown in Fig. 13, which may be bent upwardly at right angles from the bottom and welded together at the corners to provide a rigid body, or two opposite portions 3, 3 may be bent upwardly as shown and the ends of the sections closed by separate pieces welded to the bottoni 2 and the sides 3, 3.

A top 4 is secured to the upper edges of the portions 3, 3 as shown in Fig. 2, preferably by bending two adjacent sides of the top of each section downwardly to form a right angular ange 5, while the two opposite edge portions of the top are extended for a slight distance beyond the opposite sides 3 of the body, as at 6.

lt will be noted that the margins of the top members which carry the depending flanges 5 are depressed at l from the top l so as to receive the overlapping and extended portions 6 of the adjacent sections. Bolts 8 are welded to the depressed marginal portions 'i of the tops l with the heads on the lower sidesv of the tops and the bolts extend upwardly thru the portions 6 of the adjacent sections.

As shown in Fig. 11, the joint between each pair of adjacent sections is provided with a dat gasket s of rubber, cork, or other material, which is interposed between the overlapping portions 6 and 'l of the adjacent sections.

Each of the sections l is provided with an internal supporting member l@ of right-angular cross section, which is welded or otherwise permanently secured to the two adjacent sides 3, 3 of each section opposite the sides carrying the ange 5. Thus, as shown in Fig. l1, the top 4 may be welded at one or more points l i to the member l!) and at additional points i2 to the sides 3 externally of said member. Likewise the flanges 5 may be welded to the adjacent sides 3 at points i3. Thus the members of all of the sections are permanently and rigidly secured together, and each of the sections constitutes an independent pontoon.

The top of the deck is preferably reinforced internally oi' each of the pontoons or sections by means of a pair of parallel spaced members I4 of channeled cross section or otherwise, as shown in Fig. 3. When the several pontoons constituting a deck are previously formed and secured together, the deck is arranged to be supported initially in the bottom of the tank T by means of a plurality of legs or standards I5 which are suitably arranged in one or more concentric circles around the axis of the deck and suitably secured thereto. It will be observed that the legs depend substantially and to a uniform extent below the deck and are adapted to rest upon the iloor of the tank.

Each of the pontoons I is provided with a central aperture I6 and an annular neck I`I is welded to the top 4 concentrically with said aperture and forms a hand hole, by means of which access may be had individually to each of the pontoons or sections. The neck II has an annular outwardly turned flange I 8 adapted to receive a cover I9 with a depending annular ilange 20. The cover may be removably secured to the neck by means of a pair or more of bolts 2l. The cover I9 is so formed and mounted on the neck II as to protect each of the pontoons against the entrance of water to the interior thereof. In the event, however, that watershould enter the pontoons I the same may be removed readily by removing the covers I9, thereby preventing rusting of the bottoms of the pontoons.

A suitable number of the pontoons or sections may be provided with traps of the character shown in Figs. 4 and 5 for separating gas present in the tanks from the oil and for releasing the gas to the atmosphere. Preferably said traps are formed with inner and outer cylinders 22 and 23 of different diameter and held in concentrically spaced positions by means of radially disposed spacers 24 of channel cross section, or otherwise, having outwardly turned flanges which are respectively secured to the cylinders 22 and 23. The outer cylinder 22 is closed at its top 25 and extends downwardly into an opening 26 of the pontoon with which the trap is associated. Said cylinder may be welded at 2I or other points to the pontoon I, and the inner cylinder 2 3 extends substantially 'below the bottom of the pontoon and into the body of oil on which the pontoon floats. The upper end of the inner cylinder 23 is spaced from the top 25 of the outer cylinder 22.

The top 25 of cylinder 22 is provided with a cylindrical outlet 28 which extends downwardly into the cylinder 23 and slightly above the top 25. Thus any gas which may be present in the tank will rise in the space 29 between the cylinders 22 and 23 and will be deflected downwardly into the cylinder 23 and upwardly thru the outlet 28 to the atmosphere.

Usually the gas bubbles which are present in tanks of oil are charged with oil, and the peculiar form of trap I have provided will cause the fluid contents of any such bubbles to drop into the tank while the volatile elements will be discharged to the atmosphere thru the member 28. In this connection it will be noted that the compartments 29 constitute the only means provided in the pontoons for the reception of gas which may have been delivered to the tank, and the cylinders 23 being submerged substantially in the oil prevents the rise of gas therewithin.

Preferably a canopy 30 is mounted on the top of the closed cylinder 22 above the outlet 28 so as to protect the traps against the entrance of wafer, as during a rain, and at the same time permits the deilection of the gases outwardly under the canopy for dissemination.

As shown in Figs. 6 and 7, the deck D is preferably arranged with the depth of the pontoons gradually decreasing from the outer periphery of the deck inwardly to the axis thereof, thereby affording slightly greater buoyancy at the outer periphery than at the center. Due to the fact that, as shown in Fig. 11, the adjacent pontoons I areslightly spaced apart, the deck is thereby rendered more or less ilexible and the top of the deck I is higher at its outer periphery than at points near the axis thereof. Thus water which may collect on the depressed portion 3i of the deck may be readily drained therefrom by means of a flexible drain pipe 32 extending downwardly from the deck thru the oil and outwardly thru the wall of the tank T at a point near the bottom of the tank.

A suitable valve 33 may be lconnected with the pipe 32 externally of tank T for regulating the draining of the water from the deck.

Referring to Figs. 1, 14 and 15 particularly, it will be observed that the deck D is of substantially less diameter than the tank T. A suilicient space between the deck and tank is provided to allow for a flexible seal S attached to the periphery of the deck D and for closing the annular space between the deck and the tank regardless of the position of the deck in the tank. The seal S includes a flexible bellows v34 of U-shaped cross section and suitably secured at its upper margin- 35 to the top 4 of the deck and at its lower margin 36 to the periphery 31. The bellows 34 has its upper portion at least formed of airproof and Waterproof material so that water may not leak into the interior of the bellows. The bellows is held yieldably extended, as shown in Fig. 15, at a plurality of points around the periphery of the deck by means of a series 0f compression springs 38,

and the outer periphery 39 of the bellows is secured to a flexible metal bead 40 of relatively thin material and formed with corrugations 4I whereby the tension of the springs 38 will be sufficient to flex the bead 40 locally so as to closely engage the inner periphery of the tank T.

The seal is supported at its outer periphery at a plurality of points .by means of arms 42 which are pivotally held at 43 on brackets 44 inclined upwardly from and secured at their bases to the top of the deck D. The lower ends of said arms are secured to short plates 45 of arcuate cross section which are in turn secured to the corrugations 4I of the bead 40. 'I'hus the contraction and expansion of the seal S is permitted so as to conform to any irregularities in the wall of the tank.

The purpose of the seal is to prevent contact of the oil in a tank with fire or heat generated at points externally of the tank, and thus serves to preserve the contents of a tank intact. Moreover, the seal prevents excessive loss of oil by evaporation due to contact with the atmosphere.

As shown in Figs. 6 to 9 inclusive, I have provided means within the tank T and connected with the deck D for regulating and effecting the discharge of oil from the tank as the deck is lowered therein. In this connection it will be understood thatin oil storage tanks water from the well is collected in the bottom of the tank, usually with an emulsion above the water, and oil of diil'erent gravity thereabove, the oil of lowest gravity being at the top and the greatest gravity at the bottom. Accordingly it is necessary to means is of necessity arranged so that when the Y deck is lowered to a point corresponding to the lowermost level of the oil of desired gravity, the

ow of oil from the tank will cease until the discharge means is again set for an oil of lower gravity.

My present improvements contemplate the provision for the above namedpurpose of a. swinging pipe 46 connected near the bottom of the tank with aV discharge pipe 41 having a control valve 46 therein. The pipe 46 is of such length and is so arranged that the inner end of the pipe may be elevated to a maximum extent as when the tank is substantially full of oil, as shown in Fig. 6. In the vertical plane of the piper 46 and extended upwardly from the deck D I provide a hatch 49 disposed above the level of the oil. Said chamber is completely enclosed as by means of a housing 50 integral with the deck D.

Externally of the tank I provide a winch 5| manually operable by means of a crank 52 around which a cable 53 is wound and adapted for connection with the inner end of the discharge pipe 46. At the top of tank T a pair of loose pulleys 54 and 55 are commonly mounted on a shaft 56 which is carried in one or more brackets 5l secured tothe wall of the tank. In the plane of the pulleys 54 and 55 but mounted on the deck D I provide a pair of similar loose pulleys 56 and 59 which are commonly mounted on a shaft 60 carried in one or more brackets 6| mounted on the deck D. Thus, as shown in Figs. 8 and 9, the cable 53 extends upwardly from the winch 5I and over pulley 54, thence downwardly over pulley 58, thence upwardly over pulley 55, and thence downwardly over pulley 59.

On the deck D and preferably within the com# partment 49 I provide an idler pulley 62 on a shaft 69, and also withinA said compartment I provide a carriage 64 with a pair of. wheels 65, 65 supported on a radially disposed track 66. The cable 53 is extended from the cable 59 thru the housing 5 0 over idler pulley 62, thence over a pulley 61 which is suitably mountedv on a bracket 66 fixed to the inner end of pipe 46, and upwardly to the carriage 64 to which the inner end of the cable is attached by suitable means. The inclination and elevation of pipe 46 may thus be selectively established for discharging the contents of the tank lby rotating the winch 5I thru the instru-` mentality of the crank 52, and the lowering of the deck as the oil is withdrawn will not aiect the position of the pipe 46 for the reason that the arrangement of the pulleys and the compounding of the movement of cable 56 by said pulleys is such that the surplus cable between the carriage 64 and the idler pulley 62 will be automatically taken up between the pulleys on shafts 56 and 66. The carriage 64 moves longitudinally of the track 66 as the pipe 46 is adjusted to diiierent positions.

It will be obvious that when thepipe 46 is set with its innerl end slightly above the lowermost level o! oil of a desired gravity when the deck is lowered as the oil is discharged kfrom the tank the inner end of pipe 46 will be in communication with compartment 49 of. the deck as the deck nears the lowermost level of the oil and the discharge of the oil will. necessarily' cease at such point. The pipe 46 maythen be readjusted to a lower position or to a.a higher position if additional quantities of oil are supplied to the tank for further use.

Particular attention is called to the structure shown in` Fig. 11 in which the arrangement and method of securing the adjacent pontoons together is shown in detail. The pontoons being of rectangular form are independently made and assembled to form the unitary deck D but with the pontoons or sections so spaced apart and connected as to compensate for any irregularities which may exist in the pontoons and particularly to compensate for uneven contraction and expansion while the deck is in use.

'Ihe method oi' connecting the pontoons moreover provides more or less iiexibility in the deck and removes the necessity for extremely accurate workmanship in the construction of the deck. The rectangular form of the pontoons contributes to the economy of construction in that the construction of the pontoons requires less accuracy in cutting and forming than would be required for pontoons tted together on radial lines or of segmental form.

What I claim is:

1. In a floating deck for oil tanks, the combination of a tank and a deck movably supported therein and formed of a plurality of pontoons each of said pontoons having a separately formed top extended from one or more sides thereof substantially beyond the sides of the pontoon and for the reception of the extended portions of the tops of adjacent pontoons, and means for securing the overlapped portions of said pontoons together to form a unitary deck.

2i In a iioating deck for oil tanks, the combination of a tank and a deck movably supported therein and formed of a plurality of pontoons, each of said pontoons having a separately formed top, one or more edges of. which project from the sides of the pontoon and overlapping and secured to one or more adjacent pontoons, the top of each pontoon being depressed at one or more edges and provided thereat with bolts extended upwardly therethru andwelded thereto for receiving the extended portions of the adjacent pontoons.

. 3. In a iloating deck for o il tanks, the combination of a tank and a deck movably supported therein and formed oi' a plurality of pontoons, each oi.' said pontoons having a separate top extending from certain sides of the pontoon and overlapping and secured to the unextended edge portions of adjacent pontoons, said unextended portions being depressed to receive the extended portions of the tops of adjacent pontoons, each of said pontoons having a hand hole and a cover detachably mounted thereon and arranged when operatively positioned to prevent the entrance of water and the like to the pontoons.

4. A deck structure comprising a plurality of pontoons each formed with a bottom and sides,

' extended portions ofthe adjacent pontoons, and

means for securing the overlapped top portions of adjacent pontoons together for providing, a water-tight joint.

'Aman' M. GRIFFIN.

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