US2495742A

US2495742A - Seal support for floating roof tanks

Info

Publication number: US2495742A
Application number: US669905A
Authority: US
Inventors: Michael N Lebedeff
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1946-05-15
Filing date: 1946-05-15
Publication date: 1950-01-31
Anticipated expiration: 1967-01-31

Description

Jana 311, N50 M. N. LEBEDEFF 2,495,742

SEAL SUPPORT FOR FLOATING ROOF TANKS Flled May 15, 1946 2 Sheets-Sheet l Jan. 331, 395G M. N. LEBEDEFF 2,495,742

SEAL SUPPORT FOR FLOATING ROOF TANKS Filed May 15, 1946 2 Sheets-Sheet 2 W W ZZ Patented Jan. 31, 1950 SEAL SUPPORT FOR FLOATING ROOF TANKS Michael N. Lebedeif, Chicago, Ill., assignor to Chicago Bridge & Iron Company, a corporation of Illinois Application May 15, 1946, Serial No. 669,905

3 Claims.

This invention relates to a seal support, and particularly to a support for a secondary seal to be used above a principal sealing member in contact with the shell of a floating roof tank.

Floating roof tanks comprise a shell and a floating roof therein adapted to float on top of the stored liquid within the shell and rise and fall as the quantity of stored liquid is increased and decreased. In order to prevent contamination of the liquid by rain, dirt, and the like, and to reduce. evaporationlosses, it is necessary that a sealing means be provided between the roof and the shell of the tank. An efficient sealing means has been found to be a flat plate-like member that is supported from the roof and held against the shell of the tank. Flexible sealing means, usually comprised of a fabric impregnated with an impervious, flexible material such as synthetic rubber are provided connecting the flat sealing member and the roof. As the flat sealing member is usually rather heavy and therefore does not form a perfect seal with the shell of the tank, it has been found advisable to provide a secondary sealing member located above the .first sealing member. We have invented an improved secondary sealing member comprising broadly a substantially fiat metal sheet to be held against the shell above the first sealing member.

The invention also includes the improved means for supporting both sealing members from the roof so that substantially uniform pressure may be applied to the sealing members around the entire circumference of the shell of the tank in order to hold the sealing members in close contact with the shell.

The invention will be described as related to the embodiment shown in the accompanying drawings. Of the drawings Fig. 1 is a fragmentary plan view of a floating roof tank including the new secondary sealing member and the new support for both the first and secondary sealing members; Fig. 2 is a vertical section taken along line 2--2 of Fig. 1; Fig. 3 is a vertical sec tion taken along line 33 of Fig. 2; and Fig. 4 is an elevation of an improved washer bar for holding the flexible sealing member in contact with the first sealing member.

In the drawings the tank comprises a substantially cylindrical shell ID, a floating roof l I therein, a flat sheet metal first sealing member l2 held against the shell Ill, a fiat metal secondary sealing member I 3 also held against the shell and located above the first sealing member I2, and support means I 4 for supporting all sealing members.

The secondary sealing member [3 comprises a strip of fiat sheet metal having its top edge I 5 and bottom edge l6 bent back from the vertical. The sheet metal strip, which is preferably stainless steel, is provided with spaced vertical flexures ll formed of inwardly directed folds in the metal. These fiexures permit the secondary seal to expand and contract. The top edge l5 of the secondary seal is provided with spaced vertical slits I8.

The support means l4 comprises upstanding bolts l9 attached to the roof of the deck, a flat plate 20 adjustably mounted on these bolts by the top nuts 2! and bottom nuts 22, an upstanding first pipe 23 supported on the plate 20, a horizontal second pipe 24 attached near its front end to the first pipe 23, and a third pipe 25 of smaller diameter than the second pipe extending through the second pipe. There is provided a spring 26 between the plate 20 and the second pipe 24. This assembly is described and claimed in our copending application Serial No. 637,017, filed December 22, 1945, and the Henry 0. Wilbur copending application Serial No. 637,016, filed December 22, 1945.

The front end 27 of the pipe 25 is flattened horizontally and extends through an opening 28 in a spreader bar 29. The spreader bar 29 is a steel channel with the ends of the channel extending toward the shell of the tank. The spreader bar 29 is held in place bymeans of a vertical bolt 30 extending through the channel and the flattened end 27. This bolt has its bottom end extending below the channel and is provided with a head 3| with a compression spring 32 between the head and the lower portion of the channel.

At each end of the first spreader bar 29 there is located a smaller, second spreader bar 33, also formed of a steel channel of smaller width than the channel of the first spreader bar, so as to fit within the ends of the first spreader bar. Each second spreader bar is held at substantially its center by bolts 34 extending through the sides of the channels. The first spreader bar 29 is rotatably mounted around its bolt 30, and both of the second spreader bars 33 are rotatable around their bolts 34.

The first sheet metal sealing member [2 is preferably but not necessarily made according to our copending application Serial No. 636,442, filed December 21, 1945. It is provided with an inwardly extending top marginal area 35 and an outwardly turned edge 36 to provide a smooth, non-cutting edge portion. There is provided a flexible sealing member 37 extending from the top edge of the roof I I to the top of the first sealing member I2 and on to the bottom edge I6 of the secondary sealing member I3. This flexible sealing member may be a fabric impregnated with an impervious solid material, such as a synthetic rubber. It is fastened to the roof by means of a fiat washer bet-r738 held ,inzplace iby a series .of bolts 39, and is held in contact with the top of the first sealing member I2 by means of a substantially U-shaped washer bar 40 bolted by means of bolts 4I to the top of the first sealing memberl2. The top edge of the flexible sealing member 3'! is :ffastened to the bottom edge I6 of the secondary sealing member I3 by means of :a second "flat Washer bar 42.

The U-shaped washer bar 40 has its legs 43 extended toward the shell of theta-nk ami-IcQntacting the flexible sealing member 31. The base 44 of this washer bar issubstantially fiat and is provided withspaced transverse slots to give flexibility 'to'th U shaped washer bar 40. The Washer bar. is provided with inwardly extending brackets 45 engaging bolts 46 passing-through the ends pof the second spreader bars 33.

In order to support 'the secondary sealing memberIG'there are'provided upstanding arms 41 at "each end *of each second spreader bar "'33. Each arm'fil'is provided with a curved leafspring 48'at'its top-end with the leaf spring'being'arranged in horizontal position and each end of each'leaf springpassing through a slot 49-in a vertical 'fiexurell. Thereis one spring 41 providedifor each pairof-adjacent flexures I1 and each spring is so'arranged that'it serves topress thesecondary sealing memberout against the shell.

When the seal and seal support are assembled the effective distance between the two ends-of eachsecond spreader bar 33-is substantially equal tothe distance between-adjacent ends of each adjacent pair of'second spreader bars. Similarly the'effective'distance between'the ends of-each leaf spring 48'issubstantially equal to the 'distance between adjacent ends of each adjacent pair of leaf springs. The vertical fiexures It, therefore, are equally spaced around th secondary' sealing member I 3.

As shown in the*drawings,-the supports I4 are mounted on the'top deck SID-of the floating roof I land the roof is' provided witha brace under eachsupport. Ira-roofisuse'd that has notop deck the supports may rest on plates or other structural members extending across portions of the top of the roof.

Having described the invention as related to the embodiment set out in the accompanying drawings, it is intended that the invention be not limitediby any of the details oi description unless otherwise specified'but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

11..=In a floating roof tank comprising a shell, a.fioating roof therein, a metal sealing means having a substantiallyfiat portion adapted to be held in sealinglrelationship with the shell, and support means for supporting the sealing means includingza member supported on th roof extending toward the shell, an upstanding arm supported'by the extending member and a substantially horizontally arranged leaf spring supported zit-substantially its centerby the-arm the ends of said spring supporting'said portion ofthe sealing ''means and normally holding said portion against the-shell by the'spring action,

'2.'In afioating roof tank comprising'a shell, a floating roof therein, sealing means held in sealing relationship with the shell including a flat sheet metal plate having vertical flexures therein, and support-means-for supporting the sealing-means including a member-supported on the roof extending towardthe-shell, an upstanding arm supported by the extending member and asubstantially horizontal-leaf spring carried by the arm and supported at its center with the ends of the arm supporting the 'sheet metal: plate at a pair ofsaidflexures.

'3."'Ihe-support=meansof claim? wherein the fiexures arefoldsin the sheet metal extending at substantially right angles to the body of the sheet-metal and the-ends of the spring are held in slots provided in the folds.

MICHAEL N. LEBEDEFF.

' REFERENCES CITED The following referencesare of record in the file ofthis patent:

UNITED STATES :PAT'ENTS Number Name Date 1,871;289 Wiggins Aug. 9, 1932 139315551 Larson Oct.24, 1933