US1928905A - Tank roof - Google Patents

Description

A. M. MEYERS Oct. 3, 1933.

TANK ROOF Filed May 13, 1951 3 Sheets-Sheet l m F' II INVENTOR. A/f/"ca fi. Meyers A TTORNEY.

Oct. 3, 1933. MEYERS 1,928,905

TANK ROOF Filed May 13 01951 3 Sheets-Sheet 2 v N N C N A. M. MEYERS Oct. 3, 1933.

TANK ROOF Filed May 13, 1931 3 Sheets-Sheet 3 INVENTOR. A/fr a MNcye/"J ATTORNEY.

Patented Oct.. 3, 1 933 UNITED STATESPATENT O E Application May 13 '1931. Serial No. 537,043

' 14. Claims. (o1. 220-26) This invention relates to tanks for gstoring liquids and more particularly to a floating roof deck adapted to rest upon the body of liquid stored in the tank, the principal objects of the invention being to provide an insulated roof structure which maintains the liquid at relatively low temperature to prevent vaporization of its lighter components, to provide a roof structure which lies in contactwith theliquid throughout its entire area, thereby eliminating the formation of gas-collecting pockets between the roof structure and the body of liquid, and to provide both water and dead air insulators on the upper surface of the deck.

Other important objects of the invention are to adjust the buoyancy of portions of the deck proportionate 'to the load supported thereby, to provide a more efiicient and effective seal between the roof deck and the wall of the tank, and to provide automatic fire extinguishing apparatus associatedwith the deckstructure.

In accomplishing these and other objects of the invention, I have provided improved details of structure, the preferred form of which isillustrated in the accompanying drawings wherein:

Fig. 1 is a vertical sectional view through an oil storage tank equipped with a floating roof constructed in accordance with my invention.

and the floating roof therefor.

Fig. 3 is an enlarged detail perspective sec-.

tional view through a side wall of the tank, particularly illustrating the seal between the roof.

the storage tank and provide uniform submergence. r v Fig. 7 is a sectional view illustrating the lap joint connecting the segmental sealing plates.

Fig. 8 is a detail perspective view of 'oneof' thebracket arms for supporting the segmental sealing members, particularly illustrating the springs for retaining the segmental sealing members in engagement with the wall of the tank.

of the buoy members for aligning the roof deck.

. Fig. 9 is a sectional view through an inlet end oi one of the overflow pipes. 7

Referring more in detail to the drawings:

1 designates the wall of a tank for storing a body of liquid 2 which is pumped into and from the tank through a swing pipe 3. 4 designates a floating roof deck tha'trests upon the body of liquid 2 and which-is adapted to rise and fall with the level of the liquid as it is pumped to and from the tank. The roof 4'thus is in constant 5 contact with the surface of the liquid to prevent collection of air gases below the roof structure and breathing to and from the tank when it is emptied and filled, thereby preventing loss and evaporation of the lighter components of the 7 liquids, as for example, the lighter hydrocarbons when hydrocarbon oils are stored in the tank.

The roof deck 4 embodies my invention and comprises a shallow pan-like member having a flexible bottomplate 5 conforming in shape to the horizontal section of the tank and having a peripheral wall 6 extending vertically therefrom to form a shallow receptacle for containing a 7 body of liquid! to insulate the liquid stored in the tank 1. The liquid in the pan thuscovers substantially the'entire area of' the tank and provides an insulating body between the sun's raysand the body of oil to maintain a relatively low temperature of the oil and prevent excessive Fig. 2 is a fragmentary plan view of the tank vaporization of its lighter components.

The wall 6 preferably comprises a vertically positioned metal band 8 encircling the plate and secured thereto by an angle-shaped ring 9 having one of its flanges welded to the inner face of thevband and its other'flangewelded to the plate to form a bracing member and provide a liquid tight joint. The lower edge 10 of the band depends from the bottom of the plate and extends into the .body of oil to form a seal which prevents vaporized'gases from escaping about the periphery of the roof deck and stabilizes the movement of the roof deck on the liquid contained in the tank. 7 V

The lower edgeof the band is preferably reinforced by an angle member 11 having its vertical flange fixed to the inner periphery of the band and its other flange extending inwardly toward the center .of the tank, as best illustrated in Figs. 3 and 4. e V I The pan above described is smaller in diameter an annular space 12 between the wall of the pan and thewall of the tank to accommodate a segmental sealingele'ment now described, for 110 the brackets may be attached to the roof deck.

The brackets project vertically from the roof deck to'a point in substantialalignment with the upper edge of the wall 6 and terminate in up{ 1 wardly and outwardly inclined arms 15 having their free ends aligning with the wall of the pan member, as best illustrated in Figs. 3 and 4.'

Fixed to the upper edge of the wall 6 and extending inwardly therefrom is an annular sheet metal ring 16 having depending peripheral flanges 17 and 18 attached to the wall 6 and the bracket members 13 respectively. b V Spaced from the upper face of the'r'ing 16by a spacing member 19 encircling the vertical por-.

tions of the bracket members is an upper ring 20 cooperating .with the lower plate to form an annular pocket 21 having its inner end closed bythe spacing member 19v and its upper end ing leaf'portion23slidable in the pocket 21 and a preferably integral depending apron portion 24 extendinginto the body of oil in substantial alignment with the-wall 6 of the roof deck.' The apron portion 24 is preferably curved inwardly and then outwardly to form a sealing rib 25 for slidingly engaging the inner wall of the tank. The apron then curves away from the wall of thetank, as at 26, to permit itsfree passage over the joints and rivets of the tank, illustrated in:Fig. 3. I

The sealing members are preferably overlapped at their ends to form a substantially continuous sealing element about the periphery of the roof deck and are suspendingly supported against the inner wall of the tank by. rods28 which are pivotally supported from studs 29 carried at the freeiends of the bracket arms 15, the lower ends of the rods being pivotally mounted between spaced ears 30 carried on the upper face of the The lower ends'of the arms are retained in outwardly extended position by springs- 31 coiled about the studs 29 and having one of their ends bearing upwardly onthe rods 28 and their op leaf portions 22.

. posite ends bearing against the under faces of the bracket arms, as is clearly illustrated in Fig. 8.

The rings 16 and 20 and the leaf portions of thesealing members are preferably inclined from the wall of thetank toward'the pan member in order that rain and moisture will drain thereinto and away from the wall of the tank.

The annular pocket 21 therefore inclines downwardly and may be filled with a heavy body grease as indicated at 32 to provide substantially a gas .tight seal between the plateslfiand 20 and-the leaves 22 of the sealing members. The outer edge of the upper ring 20 preferably terminates short of" the ring 16 and is curved downwardly to .the grease in the pockets.

The periphery ofthe leaves 22 adjacent the walls of the tank is provided'with a flexible sealing element 22' for diverting moisture draining down the walls of the tank onto the surface of the-leaves 22 for drainage into the pan.

The bottom plate of the roof deck is provided with suitably located fittings such as gage and manhole covers, as in the usual tank construction, a 'manhole or expansion dome 34 being illustrated in Fig. 4. The manhole or expansion dome 34 comprises a cylindrical sleeve 35 having outwardly extending flanges 36 and 37 at its top and bottom, the bottom flange being secured to the roof deck in axial alignment with an opening 38 and the upper flange secures a cover member 39 to close the opened end of the sleeve. The cover member 39 is preferably bolted to the flange 3.6 with a suitable gasket 40 being inserted between the cover and flange as shown.

The cover 39 may be provided with a gage opening 41. closed by a threaded cap 42 to permit gaging depth of liquid contained in the tank.

Also formed in the cover member 39 is an opening 43 to permit the escape of gases and prevent high pressure from accumulating in the expansion dome. A- flange coupling member 44 is secured to the cover in alignment with the opening 43 for connectinga goose-neck conduit 45 having a cap 46 carrying a suitable fire screen.

Supported by the arms of the bracket members and extending circumferentially of the tank is a'pipe 47 having a plurality of outwardly extending nozzles 48 directedtoward the segmental sealing elements previously described, and having a similar nozzle 49 directed upwardly toward the terminal of the conduit 45 to distribute a fire repellant which is stored in a container 50-carried on the upper wall of the storage tank and which is in constant communication with a T fltting 51 in the pipe 47 through a flexible hose 52, illustrated in Figs. 1 and 3. The nozzles 48 and 49 are preferably provided with fuse caps which melt in a case of fire, to release the fire repellent. V

,In a tank constructed as thus far described, and in tanks employing floating decks carrying a body of water or the like for insulating the liquid stored in the tank from the suns rays, and unless the floating roof structure is provided with strengthening girders and beams to retain the pan member in rigid horizontalposition upon the liquid, sagging of portions of the pan often causes a rush of. the water to such portions and the increased weight of the water may sink the roof below the surface of the liquid stored in the tank. Also, owing to the structure of the flexible roof deck, its periphery is heavier than its central portions whichcauses the periphery of the tank to sink lower into the liquidthan the center portions. Often the center-portion is crowned above the surface of the liquid in the center of the tank, forming a gas-collecting pocket and if the crown is high enough, the water will drain therefrom to expose a portion of the pan to direct rays of the sun.

Ordinarily the swingpipes are also suspendingly supported from the roof deck and the added weight causes adjacent portions of the pan to sink below other portions so that the sunken portion carries a larger weight of water than other portions of the tank, thereby adding to the weight of the swing pipe and effects additional submergence of the deck and raising of other portions of the deck so that the water runs away from the raised portions into the lower portions, adding further submergence to the deck.

In order to overcome thesedisadvantages withof liquid throughout the area of the pan proportionate to varying the load, I provide the roof deck previously described with a plurality of buoy members adjustable to and from the bottom plate 5 for'eflecting displacement of the water and varying the depth of water under the pan proportionate to the weight'of adjacent-portions of the rook deck so that the roof deck is submerged equally throughout itsarea and so that portions of the bottom of the pan liein contact upon the surface of the liquid stored in the tank.

The buoy members 53 preferably comprise a plurality of j inverted rectangular shaped pans having a fiat top 54 and preferably integral depending sides and'ends 55 having an open bottom 56 so that when the pan is submerged "into the liquid, air entrapped within the pan will dis place the liquid in the same manner as an ordinary diving bell.

The depth of the liquid carried below each buoy member is proportionate to the amount of submergence or displacement of the buoy member, for example when the pans are moved deeper into the water, the air compressed therein forces the liquid from beneath the pan to lighten the load on that portion of the roof structure and when the pans'are raised, the depth of waterraises below the pan to-increase the weight on that portion of the roof. f

, It is thus apparent that the-load below each pan may be controlled so that the plate 5 may be loaded proportionately to obtain uniform submergence of the roof deck. I I

The buoy members or pans are preferably positioned in rows as illustrated, and spaced apart to form channels 57 for receiving the water displaced from beneath the pans and'conveying the water to other parts of the roof deck.

The pans are retained in submergence by adjustable anchor members 58 comprising J bolts having their hooked ends 59 engaged in bracket plates 60 welded to the roof deck, as best illustrated in Fig. 8. The threaded upper ends 61 of the bolts extendthrough, openings in angle members 62 having their ends 63 and 64 bearing on adjacent buoy members.

The buoy members adjacent the periphery of the roof deck may be shaped corresponding to the curvature of the wall 6 as illustrated at 65 and complementary buoy members of suitable size may be positioned around the deck fittings such as the expansion dome and drain pipes later described, so that substantially the entire area of the pan is covered by the buoy members.

In order that excess water may be drained from the channels 57 formed by the pans and to replenish'the supply, I provide drainage and supply conduits movable with the roof deck as it rises and falls with the level of liquid. in the tank.

The supply conduit 66 extends along the floor of the tankto substantially the center thereof and is connected by fiexible'pipe sections 67 and 68 with an outlet pipe 69 fixed to and supported vertically by the bottom plate of the roof deck, as illustrated in Fig. 1.

, The drainage conduiti70 may extend parallel with the conduit 66 and is connected by suitable flexible connecting members 71 and 72 with a distributing manifold 73. Radiating from the manifold are a plurality of drainage pipes 74 suspended from the bottom of the roof deck by brackets 75 and terminating in vertical extensions 76 extending through sumps 77 formed in the bottom of the roof deck. Threaded on the extensions 76 are sleeves 78 whereby height of the extensions may be adjustably positioned to maintain afixed level of liquid in the channels 57. The swing pipe 3 previously mentioned, is swingly mounted in the tank and its free end is pro vided with trolley wheels 79 operating on a cable 80 having one end fixed to the bottom of the tank,.as at 81, and running over pulleys 82, 83, 84 and 85 carried by the roof structure below the plate 5. The cable then extends upwardly through a stuffing box 86 in the bottom of the pan, over they pulleys 87 and 88 carried on the rim of the tank, and then downwardly to wind on a windlass'89., 7

When the indlass 89 is operated to wind the cable the mouth of theswing pipe may be raised or lowered to discharge the stored liquid at any desired levelin the tank.

7 Attention is directed to the fact thatthe arrangement for suspending the swing pipe does not disturb the equilibrium of the roof deck when the swing pipe is operated and also to the fact that the swing pipe and its suspending cables prevent rotation of the roof deck in the tank.

plate 5 may be aligned in a substantially true,

plane. 7 V r The water displaced by the pans may rise in the channels 57 and fiow to fill spaces belos pans located adjacent lighter portions of the deck structure. Should weight be applied to any one of the pans, the pan will be submerged to cause the water to flow from beneath the pan so that the weight on'that portion of the roof structure is reduced substantially proportionate I to the weight applied to the pan. 7

As soon as the weight is relieved,- the water will again raise the pan to its original position so that the bottom plate 5 is kept in a substantially true plane regardless of varying weights that may be exerted on the buoy members.

It isalso apparent by employing a plurality of buoy members to produce the channels 57, sudden depression of any portion of the roof will not cause the water to rushto the depressed portion to sink the'roof deck, but the water will be checked by the protruding portions of the pans and be distributed slowly through the channels. When the pressure tending to depress the roof deck is relieved the Water will seek its normal level by flowing back through the channels.

It is also apparent that I have not only provided the liquid insulator, but by the inverted pan construction I have also provided a dead air insulator covering substantially the entire area of the pan,

and that the air insulator not only adds to the adjusting the buoy members to and from the roof member to vary depth of said liquid loading means between the buoy members and the'roof member to effect substantially uniform submergence of the roof member throughout the area of the tank;

2. A floating roof deck forliquid storage tanks comprising a flexibie roof member adapted to float upon the surface of the liquidcontained in the storagetank, liquid means for loading said roof member, a plurality of buoy members floatable upon said liquid loadingimeans, and means for adustably submerging the buoy members to vary depth of said liquid loading means.

3. A floating roof deck for liquid storage tanks comprising a pan member adapted to float upon the liquid in a storage tank, a body of'fluid contained in the pan member to insulate the liquid in the storage tank from exterior heat, andmeans supported by. the fluid in the pan member for adjusting submergence of the pan member uniformly in the liquid in the tank.

4. A floating roof deck for fluid storage tanks comprising a pan member adapted to float upon the fluid in a storage tank, a body of liquid in the pan member to insulate the fluid in the storage tank, drain members associated with said pan for controlling the amount of liquid carried in the pan member, liquid displacement 30 means floatable on the liquid carried by the pan member, and means for adjusting the displacing means for normally maintaining fixed levelsof the liquid over selected areas ofthe pan member and yieldable under pressure applied to the liquid displacement means to effect displacement of liquid proportionate to the applied pressure for retaining the entire area of the pan member in substantial contact with the fluid in the tank.

5. A floatingroof deck for liquid storage tanks, comprising a pan member adapted to float on the fluidin astorage tank, a body'of liquid in the pan member to insulate the liquid in the storage tank, means for controlling the amount of liquid carried in the pan member, and buoy members carried upon the liquid contained in the pan member for adjusting the pan member in substantially uniform contact with the liquid 7 in the tank.

, 6. A floating roof deck for liquid storage tanks comprising a pan member adapted to float on the liquid in the storage tank, a body of liquid contained in the pan member to insulate the liquid in thestorage tank, buoy members floatable upon the liquid in the pan member, and'means for adjustably submerging said buoy .members for controlling the amount of liquid below said buoy members.

7. A floating roof deckfor liquid storage tanks 8. A floating roof deck for storage tanks com-' prising a pan member adapted to float upon the liquidin a storage tank, a body of liquid con-' tained in and covering the area of the pan for insulating the liquid in the storage tank, and buoy members comprising a plurality of inverted pans floatable upon the liquid carried in the pan member, and means for submerging said inverted pans to control level of liquid carried in the pan member. I

9. A floating roof deck for liquid storage tanks comprising a pan member adapted to float upon the liquid in a storage tank, a body of liquid carried in the pan member to insulate the liquid in the storage tank, a pluralityof float members carried upon the liquid inthe pan member, anchor members interconnecting said floats to se: cure the floats to the pan member, and means for adjusting said anchor members to vary submergence of the floats.

10. A floating roof deck for liquid storage tanks comprising a pan member adapted to float upon the liquid in a storage tank, a body of liquid carried in the pan member to insulate the liquid in the storage tank, a plurality of spaced rows of, float members carried uponthe liquid in the pan member, and means for variably adjusting the float members to effect substantially uniform contact of the pan member with the liquid contained in the storage tank.

11. Incombination with a storage tank, a roof member for the tank comprising a pan to float upon the surface of liquid stored in the tank, means for sealing the periphery of the pan with walls of the tank, a body of liquid carried in the pan to insulate the'liquid in the storage tank, and, air containing members floatable upon and substantially covering the surface of the liquid in the pan to supplement insulation qualities of the liquid in the pan. 7

12. In combination with a liquid storage tank, a roof for'the tank comprising a pan adapted to float upon the surface of liquid stored in the tank, segmental members for sealing the periphery of the pan with thewalls of the tank, a body of liquid contained in the pan to insulate the liquid in the storage tank, and means comprising a plurality of air containing float'members for, controlling the depth of liquid in the pan.

13. In combination 'with a liquid storage tank, a roof for the tank comprising a pan adapted to float upon the surface of liquid stored in the tank, and having an annular pocket, segmental. sealing members slidable in said annular pocket to engage the wall, a plastic sealing means in the annular pocket, a body of liquid contained in the pan to insulate the liquid in the storage tank, and means comprising a plurality of air containing float members for controlling the depth of liquid in the pan.

14. A roof deck for liquid storage tanks includmg a flexible roof member arranged to rise and ALFRED M. MEYERS.

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