US2318134A - Seal for floating tank roofs - Google Patents

Description

y I J. H. wlsems. I 2,318,134

SEAL FOR FLOATING TANK ROOFS Filed May 24', 1940 4 Sheets-Sheet l W111 F I64 ,5

w 13 7 7 i a A h 4 B at? if 2; I N VENTOR JOHN H-WIGG/NS BY ATTORNEY May 4, 1943. J, H. WIGGINS SEAL FOR FLOATING TANK ROQFS 4 Sheets-Sheet 2 Filed May 24, 1940 FIGS.

' INVENTOR, OHN .W/GGINS r ORNEY I I llllflllli May 4, 1943- J. uwxcssms SEAL FOR FLOATING TANK ROOFS Filed May 24, 1940 4 Sheets-Sheet 3 FIG. 8.

FIG. I2.

INVENTORI JOHN H. W/GG/NS BY TORNEY May 4, 1943- J. H. WIGGINS SEAL FOR FLOATING TANK ROOFS Filed May 24, 1940 4 Sheets-Sheet 4 FIG. I3.

I NVENTOR, JOHN H. W/GG/NS ,4 TTORNEY F'IG.I4.

Patented May 4, 1943 SEAL FOR FLOATING TANK ROOFS John H. Wiggins, Chicago, 111. Application May 24, 1940, Serial No. 337,020

In Great BrltainDecember- '1, 1939 s Claims. (01. 220 -26) This invention relates to floating tankfroot V seals of the type that comprisev an annular metal shoe arranged in sliding engagement with the side wall of the tank, swinging hangers on the floating roof that support said shoe, and a primary seal or closure for the annular spacebetween the shoe and the floating roof, formed usually from gas-tight fabric attached to the shoe and to an annular. rim on the outer edge or peripheral portion of the floating roof.

In my pending application for patent Serial No. 247,031, flied December 21, 1938, I have described a floating tank roof seal of the general type above referred to, in which the side wall shoe is suspended in a novel manner from the hangers on the floating root, and is provided at its upper edge with an auxiliary seal or secondary seal that is held pressed tightly against the inner face of the tank side wall, so as to seal the space or joint between said wall suspended from the hangers on the roof. My present invention has for its main object to improve the operation, reduce the cost, and facilitate the construction or erection of a floating tank roof seal that has one or more of the distinguishing features or characteristics of the seal described in my said pending application, and which comprises elements that are similar in general construction and principle of operation to some of the elements or parts of the seal described in said application. In order to attain or accomplish the above mentioned objects, I have devised (l) a novel means or novel devices for joining or connecting the fabric parts of the seal to the metallic parts: (2) a novel means or novel devices for pivotally attaching the suspending links on the hangers to the side wall and the shoe,

shoe; and (3) a novel type of mounting or supporting means for the secondary seal at the top edge of the side wall shoe.

The novel means and devices that constitute my present invention, are capable of being used independently of each other in floating tank roof seals of the general type first referred to. Accordingly, I do not wish it to be understood that my improved fabric attaching or securing means is limited to use in a seal in which the side wall shoe is sustained, supportedor suspended in the particular manner herein disclosed, andI do not wish it to be understood that the particular secondary seal or auxiliary seal herein disclosed is limited to use in a floating tank roof equipped with a side Wall shoe and a primary seal of the particular construction herein illustrated and described.

Figure .1 of the drawingsis afragmentary top plan view of a floating tank root seal constructed in accordance with my present invention.

Figure 2 is an enlarged vertical sectional view, taken on the line 2-2of. direction indicated by the arrows.

Figure 3 is avertical'sectional 'view, taken on V in the direction the line 3-3 of Figure 1, looking indicated by the arrows.

Figure 4 is a sectional view of one of the clamping devices used to hold or secure the reenforcing ring to the lower edge portion of the shoe.

Figure 5 is a vertical view, taken on the line 5-5 of Figure 1, looking in a the direction indicated by the arrows and showing some of the .tion. 7

Figures 6 and 7 are vertical sectional views, taken on the lines 6-6 and 'I,'! of Figure 5, looking in the direction indicated by the arrows.

Figure 8 is a horizontal sectional view, taken on the line 6-8 of Figure 5.

Figure 9 is a vertical sectional view, taken on the line 9-9 of Figure 5.

Figure 10 is an enlarged detail view, illustrating how the fabric constituting the secondary seal is attached atitstop edge to one of the spring-pressed rockable carriers employed to support the secondary seal and hold it pressed tightly against the tank side wall.

Figure 1 1 is a perspective view of-one of the .dual clamping plates or double-acting plates used 'to attach to the side wall shoe.-

Figure 12 is a perspective view of one of the single-acting clamping plates used to attach the primary seal to the shoe.

looking outwardly towards the side wall of the tank, illustrating the method of assembling and.

combining the metal side wall shoe; and

Figure '14 is an enlarged cross-sectional view of the tank side wall, taken on the line I4l4 of Figure 13.

In the accompanying drawings, l designates a tank side wall of circular form, 2 designates a floating roof of the pontoon type, pan type, or any other type arranged inside of the tank so as to float on the liquid :1: in the tank, A designates an annular side wall shoe arranged vertically in sliding engagement with the side wall I, B designates a primary seal, usually formed from fabric, attached to the shoe'A and to the peripheral portion of. the floating roof -2 so as to form a plates that constitute the Figure 1, looking-in the iragmentary sectional 7 parts of the seal in elevathe primary seal and secondary seal' ondarysealorauxiliary waliandtheshoeAJ) closure forthe also space between the roof and the'side wall of the tank, C designates a sec-.

- em on the roof 2 arranged-so that rollers or fricor links suspended from tion-reducing devices I at the upper ends of same bear against the inner face of the tank side wall. and l designates vertically-adjustable rods the upper ends of the hangers D and attached to theinner side of the shoe A so as to suspend said shoe from the hangers in such a way as to insure the proper cooperation of the tank; The parts Just descrimd are ofthe same general construction and arrangement as the corresponding parts of the structure disclosed in my pending application for patent previously referred to, but in my improved seal herein illustrated certain new features or additional features have been incorporated into the structure for the purpose of improving. the operation of the seal. reducing the cost of manufacture of same, and simplifying the operation of installing the seal.

One novel feature of my present invention consistsof the means used to attach the primary seal B and the secondary seal C to the shoe A. Briefly described, said means comprises a plurality of double-acting or dual clamping plates I and a plurality of single-acting clamping plates I bolted to the inner side of the shoe A and arranged so as to clamp or hold clamping rings or rods I and I, as illustrated in Figure 5, each of the dual clamping plates 8 being connected to the shoe by a bolt I, and each of the single-acting clamping plates being connected to the shoe by a bolt I. The single-acting clamping plates I, which are shorter than the dual clamping plates I, co-act only with the ring 1 and are used to attach the outer edge of the primary seal B to the shoe A, said ring I being arranged so as to lap over, engage, or "bear upon the primary seal B at a point slightly below the top edge of same, as illustrated clearly in Figures 2 and 3. The long clamping plates or dual clamping plates I co-operate with the clamping means I for the primary seal, and also engage the clamping ring I which engages or presses upon the secondary seal C at a point slightly above the bottom edge of said seal. This method of attaching the fabric elements B and C to the side wall shoe overcomes the necessity of forming holes in said elements, because the form the elements are spaced apart. 6. Another advantage of adjacent edges of said as shown in Figure such a constructionis. that the retaining clamps I and I can be loosely bolted to the shoe A, and thereafter, the fabric elements B and C can he slipped into operative position between the inner side ,of the shoe A and the retaining rings, rods or devices 'I and 8 on which the clamps I and I exert pressure in a direction to tightly clamp the primary and secondary seals B and C to the shoe A. In orderto facilitate the operation of installing the seal, each of the short or singleacting clamps I is provided at its lower end with an inwardly-projecting portion I", and is provided at its-upper end with an inwardly-projecting portion 8, as shown in Figure 12. The portions I" at the lowerends of. the clamps I perfunction of a temporary holding or sustaining means for the clamping ring 1 associated 'theshoeAandtheclampi ringIintheopcr.

ation of attaching the secondary seal to the side wall shoe. The dual clamping plates I are intended to be loosely bolted to the shoe A, after the primary seal B has been attached to said shoe. and in order that said plates I may be used to temporarily hold or position the clampshoe with the side wall of the A ing ring I that co-acts with the secondary seal C, prior to tightening the nuts on the bolts I, which sustain the clamping plates I, each of said plates is provided adjacent its upper end with an inwardly-projecting portion I", as shown in Figure 11, disposed so that after the plates I have been mounted on the shoe, by means of the bolts I", the clamping ring or rods I can be positloned'upon the portions l of the plates I, with the result that the ring I is in proper position to clamp the secondary seal C to the shoe when r the retaining bolts for the plates I are tightened, as shown in Figure 5. The clamping plates I and I are arranged in spaced relationship around the entire circumference or area of the annular side wall shoe A to which they are bolted.

Theside wall shoe A may be of any preferred construction. so long as it is of substantial height and has sufhcient circumferential flexibility to conform, or approximately conform. to the shape of the curved or circular-shaped side wall I of the tank. Said shoe may be composed of a plurallty of segmental-shaped shoe members. whose ends are Joined together by gas-tight flexible connecting devices, or it may consist of a single shoe that extends practically continuously around the side wall of the tank. Preferably, said shoe A is constructed in the form of a split ring, whose gap or joint is protected by a sealing device that provides for the expansion and contraction of the shoe. In order that the shoe will be relatively light in weight, strong enough to successfully perform its function, and still be capable of flexing circumferentially sufficiently to conform to the curvature of the side wall of the tank, I prefer to construct the shoe from relatively light weight sheet metal and provide the top and bottom edge portions of same with reenforcing or strengthening devices. Thus, if the shoe A is formed from relatively light weight sheet metal.

with the primary seal B, and the portions I at 18 such, for example, as No. 16 extra heavy galvanized steel, the clamping ring I that isused to press the secondary seal C tightly against the shoe A, also performs the function of a re-enforcing or strengthening device for the upper edge portion of the shoe. The lower edge portion of said shoe can be re-enforced or strengthened by a ring I that extends circumferentially around the shoe and which is clamped to the inner side of the lower edge portion of the shoe by clamps ll. secured to the shoe by bolts I 0", as shown in Figure I. Preferably, the top and bottom edge portions of the shoe A are bent laterally slightly,

so as to insure that the shoe will slide over any,

slight protuberance or raised surface on the inner face of the tank side wall. the re-enforcing rings 8 and 8 being of material assistance in such a deforming operation, inasmuch as they are located in relatively close proximity to the top and bottom edges of the shoe and extend circumferentially around the shoe. The secondary seal or auxiliary seal C is supported in such a position that it projects upwardly from the top edge of the shoe A, and it is held pressed tightly against the tank side wall I. so as to form an efl'ective seal between thetank side wall and the shoe A. The means used to supp r the upper end portion of the auxiliary seal C; and press said seal against the tank side wall at a point above the top edge 01'- the shoe A. consists of supporting devices or carriers that move radially with relation to said shoe. Said radially-movable supporting devices or carriers can be constructed and arranged in various ways, without departing from the spirit of my invention, and various means may be used -to cause said devices to exert sumcient outward pressure on the upper end portion of the auxiliary seal C to hold said auxiliary seal in sliding engagement with the side wall of the tank. In the form of myinvention herein illustrated, the bottom edge of the secondary seal is clamped tightly to the shoe A, as previously described, and the top edge of said secondary seal is attached to a plurality of spring-actuated, rockable or oscillating carriers that are pivotally mounted on the inner side of the shoe A, in such a way as to move radially in relation to said shoe. Said carriers consist of relatively short units arranged end to end so that they extend circumferentially around the entire circumference of the shoe, and they are of such construction that they can bemounted quickly and easily on the shoe and attached to the seal C. In the drawings I have used the reference character E to designate the body portion of each of the carriers just referred to. The particular construction of said carriers is not essential, and they can be mounted on the side wall shoe in vaious ways, so long as they are constructed or arranged so that they will hold the secondary seal C in proper position, without depending upon any inherent strength in the fabric of which said seal is constructed, and will be constantly under the influence of a means, preferably a spring means or resilient means, that exerts pressure on the seal 0 in a direction to hold said seal in snug engagement with the inner face of the tank side well. One convenient and inexpensive way of constructing said carriers is to provide each carrier with a horizontally-disposed body portion E, to which the top edge of the fabric C is detachably connected, and equip said body portion E with depending arms I i that are mounted on the inner side of the shoe A in such a way that'said arms are capable of rocking on horizontal axes towards and away from the tank side wall. Each carrier may be provided with a pair of rock arms H, whose lower ends are adapted to be inserted in holes in a horizontally-disposed shaft i2, and secured to same by nuts l3 mounted on threaded portions at the lower ends of the arms H during the operation of installing the seal. The rock shaft l2 to which the arms i I are attached, is supported in bearings M on certain of the clamping plates. Herein said f bearings are shown as being welded or otherwise rigidly connected to some of the clamping plates 5 and projecting laterally from same, as shown in Figure 5 and in Figure 8. The force or pres- I sure used to operate the carriers E, is herein illustrated as consisting of torsion springs l5 mounted on the rock shafts l2 of'said carriers in such a way as to exert constant pressure on said carriers in a direction tending to move the body portions Eof same outwardly towards the side wall of the tank. In installing the carriers each of the springs I 5 is mounted on the shaft l2 with which it co-operates in such a way that one end of the spring will be anchored to the shaft. After the arms ll of the carrier have been attached to the shaft 12, the spring is is placed under tension, and alaterally-proiecting arm it at the free end of the spring is snapped into engagement with one .of the plates 5, as

other separate fastening devices. Preferably, the

body portion E of the carrier is made substantially channel-shaped, so that the legs of same can be spread slightly; as shown in brokenlines in Figure 10, to receive the edge of the fabric C. Thereafter, the top leg or top member of the body portion of the carrier is bent downwardly to exert clamping pressure'on the fabric, and if desired, slitted or deformed parts I6 01 said top leg can be bent downwardly so as to formfin effect, spurs or retaining devices that securely attach the fabric C to the spring-pressed member E, which sustains the fabric C and holds it tightly pressed against the tank side wall.

The rods or links 4, previously mentioned, that are used to suspend the side wall shoe A from the upper ends of the hangers D, are adjustably connected to said hangers, preferably by adjusting nuts 4 on said rods that are arranged above and below perforated lugs 4* on the upper ends of the hangers D, as shown in Figure 2. The lower end of each of the suspending rods or links 5 is pivot ally attached to the inner side of the side wall shoe A, preferably by' a horizontally-disposed shaft or pin I! (see Figure 5) carried by a pair of the dual clamping plates 5,, previously de-' scribed, that form part of the means employed to connect the fabric to the shoe A, the lower end of the suspending rod or link 4 being provided with a strap 18; as shown in Figures 6 and '7,

through which the horizontally-disposed shaft or pin I1 extends.

After the shaft ll has been inserted in the strap or hearing I8 at the lower end of the link 4 with which saids'haft co-operates, said shaft I1 is then welded to a pair of plates 5, so as to form a unit. In the operation of installing the seal said unit is mounted on the shoe A by means of the boltsi Consequently,

some of the dual clamping plates or double-acting clamping plates 5, in addition to functioning as clamping devices for the rings 1 and 8 employed to attach the primary and secondary fabric seals to the side wall shoe A, also serve as supports for pivot or pintle pins (the horizontally-disposed shaftsor pins l1) that join thesuspending links shoe plates in such a position relatively to each other before they are connected together, that the topand bottom edges of the shoe, after the shoe is completed, will -conform to irregularities in the horizontal joints of the tank side wall. In other words, instead of building the shoe in such a manner that it has perfectly straight, or perfectly horizontal, top and bottom edges, I have devised a method by which the shoe can be easily erected in such a way that if the horizontal joints in the tank side wall are nottruly horizontal, or

- wall at another point.

be varied easily (by manipulating the nuts 4') so as to accommodate or provide for irregularities inthe top and bottom edges of the shoe. In

Figures 13 and 14 I have illustrated a method of building the shoe A inside of the tank, or after the side wall I of the tank has been erected. As shown in said figures, the reference character 9 designates horizontal joints in the side wall of a tank. which may have a relatively great diameter, say,'for example, a diameter in excess of 100 feet or more. After the side wall has been erected, lugs II are temporarily welded to the tank side wall at various points and in such position with relation to a horizontal joint of the side wall,

that said lugs are spaced an equal distance, or the same distance, from said horizontal joint. Sections of the side wall shoe, as indicated by the reference character A". are then mounted upon the lugs II, and the adjacent vertical edges A of the shoe plates are connected together. usually by riveting. In this manner any irregularity vertically that exists in the horizontal side wall joint 1 which constitutes the datum to which the shoe is erected, is followed after all the shoe plates A" have been joined together. After the shoe has been completed. and while the root is-fioating on the liquid in the tank, the shoe is mounted in proper position on the roof hangers by means of the links 4 which are adjusted vertically, so as toarrange the shoe in correct position. the lugs being removed from the tank side wall after the adjustment of the shoe suspending links has been completed. It has been demonstrated in actual practice that this method of constructing and mounting a side wall shoe greatly improves the operation of the seal. because the shoe accurately conforms to any vertical irregularities that may exist in the horizontal joints of the side wall, and is then hanging like a curtain in exactly malaise the top and bottom edges of'the shoe built, if easily attained contact of the full surface of the shoe with the tank side wall be attained.

Having one horizontal tank seam to use as a datum for hanging the shoe when in service, is atremendous help, because. then all the horizontal tank seams are a datum, since every point in all i of them is equidistant from-a similar point in the next seam vertically beneath it. In other words, if the original datum waves up and down, all other horizontal tank seams wave up and down in just the same manner.

It is believed that from the preceding descrip- 4 tion of my invention it will be clear how the co- I the clamping ring I on theholding portions 8" acting members or parts of my improved seal are assembled and combined during the operation of erecting the seal, and while considerable latitude is permissible, in, the exact procedure employed in erecting the seal, I have found it to be preferable to first attach the primary seal B tothe side wall shoe A by first temporarily bolting the clamping plates 6 to the shoe, then positioning at the lower ends of the plates 8, then forcing the top edge of the i'abric'B upwardly between the shoe and the clamping ring 7, after which the nuts on the bolts 6" can be tightened. To install the secondary seal C, it is only necessary to loosely bolt the dual clamping plates 5 to the side wall 7 shoe, then position the clamping ring 8 on the ring supporting portions 5 of said clamping plates 5, and then force the bottom edge of the fabric C downwardly betweenthe shoe and the. ring 8 until said bottom edgestrikes against the inwardly bent portions 8 of the clamping plates 6. Subsequently, when the nuts on the bolts 5 are tightened, the lower edge portion of the fabric C will be sure to be in proper position to be engaged by the clamping ring 8. due to the fact that the portions 6 of the clamping plates 8 that served as stops for the bottom edge of the fabric' 0 are arranged in a slightly lower position than the ring supporting portions 5? of the clampingplates 5. Ifdesired. some of the plate 6 can be the same shape as it was erected and with an easily available datum for checking the whole vertical travel of the roof, since every tank circumferential seam is parallel to all others. This is a radical departure from the prior procedure of building the shoe with straight top and bottom edges. and then using said shoe with a side wall having wavy horizontal joints, some portions of which were always disposed in angular. relationship with the top and bottom edges of the shoe. My method or. procedure makes it possible to prodisposed in a level position, but the side wall shoe carried by said roof has a top that follows In other words, with a long limber cylinderlike shoe. it is essential that it be hung like it is duce a structure in which the floating roof is used to temporarily hold or position the clamping ring 8 during the operation of attaching the secondary seal to the side wall shoe. inasmuch as the bolts 6 pass through the plates 6 slightly off center, with the result that if any one of the plates 8 is turned upsidedown, or in the reverse of its normal position, it will be long enough to engage or co-operate with the clamping ring 8 'to' temporarily hold the same while'the plates 5 are being loosely bolted to the shoe. Similarly, the installation of the parts which constitute the spring-pressed carriers for the secondary seal C can be effected quickly and easily, simply by mounting the springs ii on the rock shafts i2. positioning the said shafts in their bearings l4. and attaching the two arms ll of each carrier to the rock-shaft I: with which they co-operate. To fasten the top edge of the secondary seal to the carriers E. it is only necessary to insert the edge portion of said seal in the channel-shaped body portions E of the carriers and deform the top parts of said body portions so as to bind or grip the fabric constituting the secondary seal. By using some of the long or dual clamping plates 5 forming part of the fabric clamping means, to support the pivots or pintle plus I] by which the depending rods 4 on the hangers are attached to the side wall shoe, I effect another economy in the cost of constructing and installing the seal. In the operation of tightening the nutson the supporting bolts of the clamps 5 and 8, the heads of said bolts exert sumcient prestion of a side wall shoe,

' mounting the carriers on said plates, as was the gendescribed in my prior application previously men- I tioned.

Having thus described my invention, what I claim as new and desire to secure by Letters Patentis:

1. A floating tank roofseal provided with a side wall shoe, a secondary seal arranged at the top edge of said shoe and adapted to press against the tank side wall, the bottom edge of said secondary seal being attached to the shoe, and rockable carriers on the inner side of, the shoe, projecting upwardly from same and attached to the top edge of the secondary seal, for supporting the upper end portion of said secondary seal.

2. In a floating tank roof seal, the combinaa plurality of springactuated, rockable carriers mounted on said shoe and projecting upwardly above the top edge of same, and a fabric sealing element attached at its lower end to the shoe and suspended from said carriers said sealing element being pressed against the tank side wall by said spring-pressed carriers.

3. A floating tank roof seal provided with a side wall shoe, rockable carriers mounted on said shoe adjacent the upper edge portion 01 said shoe and provided with portions that project higher than the top edge of the shoe, a sealing element attached to said carriers and to said shoe and maintained by said carriers in a substantially upright position in engagement with the tank side wall, and means for detachably shoe.

4. A floating tank root seal, comprising a side wall shoe, a sealing element having a portion disposed above the top edge of said shoe, se-

curing clamps detachably connected to the shoe for fastening said sealing element to the shoe, and rockable carriers removably mounted on said clamps and attached to the upper end portion or said sealing element, said carriers being ar-' ranged so as to press the sealing element against the tank side wall.

5. A floating tank roof seal, comprising a side wall shoe, a sealing element arranged at the top edge of said shoe, securing clamps on the shoe for detachably connecting said sealing element to the shoe, and rockable carriers on the shoe attached to said sealing element and arranged so as to press said sealing element against the tank side wall, said carriers being removably mounted on said securing clamps, and torsion springs combined with said carriers so as to constantly exert pressure on said carriers in a direction to hold said sealing element in engagement with the tank side wall.

6. A floating tank roof seal provided with a side wall shoe, a fabric sealing element detachably connected to the top edge portion of said shoe and projecting upwardly from same, and rockable carriers on the shoe projecting above the top edge of same and provided with portions that embrace the 'sealing'element so as to attach said sealing element to the carriers, said portions being adapted to be deformed so as to tightly grip said sealing element.

7. In a floating tankroof seal, the combination of a side wall shoe, a primary sealing element and a secondary sealing element arranged in spaced relationship adjacent the top edge of the shoe with the secondary sealing element pro- Jecting upwardly above the shoe, a clamping means for both of said sealing elements mounted on the shoeat a point between said two sealing elements so as to fasten said sealing elements to the shoe, and spring-pressed, rockable carriers removably mounted on the inner side of the shoe and having portions that are adapted to be deformed so as to grip and hold a portion of said secondary seal that is disposed above the top edge of the shoe.

8. A floating tank roof seal provided with a side wall shoe, 8, flexible sealing element attached to said shoe and projecting upwardly above the top edge of same, a radially-movable means on said shoe for supporting the upper end portion of said sealing element, and means for causing said radially-movable means to exert pres sure on said sealing element in a direction to hold said element in snug engagement with the tank side wall at a point above the top edge of said shoe.

JOHN H. WIGGINS;

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