US3831800A

US3831800A - Floating roof plural position suspension

Info

Publication number: US3831800A
Application number: US00255841A
Authority: US
Inventors: D Korn
Original assignee: Tresco Inc
Priority date: 1972-05-22
Filing date: 1972-05-22
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27

Abstract

This invention describes a system by means of which a floating roof inside of a closed roof tank can be supported at two or more vertical positions within the tank by means accessible at the fixed roof of the tank. The floating roof is constructed inside of the closed roof tank and is made up of a horizontal plasticfiberglass plate with foam plastic filler to provide a unitary construction that will float on top of the surface of a liquid in the tank. There are a plurality of flexible tensile members which are attached to the floating roof and are anchored at a plurality of fixtures on the fixed roof so that the tank can be supported by these tensile members irrespective of the level of the supporting liquid in the tank.

Description

Waited States Patent [1 1 [111 3,831,800 Kern Aug. 27, 1974 [5 FLOATING ROOF PLURAL POSITION 3,445,026 5/1969 Korn 220/26 s SUSPENSION R26,264 9/1967 Beach 52/3 [75] Inventor: Donald L. Korn, Sapulpa, Okla. Examiner wimam 1 price [73] Assignee: Tresco, Incorporated, Sapulpa, Assistant Examiner-Stephen Marcus Okla. Attorney, Agent, or Firm-Head & Johnson [22] Filed: May 22, 1972 57 ABSTRACT [2l 1 Appl. No.: 255,841 This invention describes a system by means of which a floating roof inside of a closed roof tank can be supported at two or more vertical positions within the '8 tank by means accessible at the fixed roof of the tank. [58] w S 26 The floating roof is constructed inside of the closed 52/3 roof tank and is made up of a horizontal plasticfiberglass plate with foam plastic filler to provide a unitary construction that will float on top of the sur- [56] References Cited face of a liquid in the tank. There are a plurality of UNITED STATES PATENTS flexible tensile members which are attached to the 1,244,220 10/1917 Lorcher 52/3 floating roof and are anchored at a plurality of fixtures Hll'SCh R on the fixed roof so the tank can be Supported l,448,226 3/l923 Mattson 52/3 these tensile members irrespective of the level of the 2,057,682 10/1936 Horton et al 220/26 R Su in h uid in the tank 2,847,142 8/1958 McClintock et al 220/26 SA ppo g q 3,240,381 3/1966 Smith 220/26 S 40 6 Claims, 3 Drawing Figures IR\\\\\\\ \7I\/.

FLOATING ROOF PLURAL POSITION SUSPENSION CROSS REFERENCE TO RELATED APPLICATION This invention is related to my issued U.S. Pat. No. 3,445,026, issued May 20, l969, entitled: FLOATING ROOF STRUCTURE.

BACKGROUND OF THE INVENTION This invention is in the field of floating roofs for tanks, particularly those which have a closed roof over the tank. Such floating roofs are fully described in my U.S. Pat. No. 3,445,026, and are for the purpose of minimizing vapor losses as a safety measure to prevent explosions, or asphyxiation of personnel, and to mitigate air pollution. In the use of such floating roofs it is important that there be means to support the floating roof from the tank at least at two levels, so that when the tank is empty the entire inside surface of the tank can be cleaned by personnel who are admitted to the space through convenient manholes. There may also be reasons for supporting the floating roof at more than two positions.

It is an object of this invention to provide a convenient, simple system whereby personnel outside of the tank itself can adjust means to support the floating roof at any desired level inside of the tank.

The background of this invention is exemplified by my US. Pat. No. 3,445,026, which describes the con struction of the floating roof and illustrates means by which the floating roof can be supported at its lowest position either by means of long tensile members anchored to the fixed roof, or by means of supports arranged along the wall of the tank, etc. Also, there are means shown by which the floating roof can be supported from the sidewalls of the tank by means of flexible tension members which are attached to the floating roof and can be hooked to appropriate means on the tank wall by personnel who have entered the spaced above and are supported by the floating roof.

While these means for supporting the roof at inter mediate points are mechanically adequate, it is often inconvenient and/or dangerous for personnel to enter the space above the floating roof in order to provide the adjustments necessary to support the roof at an upper or intermediate position.

SUMMARY OF THE INVENTION The above objects are realized and the limitations of the prior art are overcome in this invention by providing openings in the fixed roof ofthe tank and the use of flexible tension members which are attached to the floating roof vertically below these openings. The tension members can be attached to a cover plate or to the fixed roof itself within these openings and by the use of adjustable clamps, or by the use of loops or rings on the tension members, and appropriate hooks. The floating roof can be supported at any desired elevation within the tank which is predetermined in advance, or can be adjusted at any time by, changing the positions of the clamps attached to the flexible tension member.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the principles and details of the invention will be evident from the following description taken in conjunction with the appended drawings, in which:

FIGS. 1 and 2 illustrate two embodiments of a system for adjustably supporting the vertical position of a floating roof inside of a closed roof tank.

FIG. 3 is an alternative variation of the embodiment of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention is an improvement on my U.S. Pat. No. 3,445,026, wherein there is a full description of the construction and use of such a floating roof, and certain means for supporting a roof at two selected levels in the tank. The corresponding drawings and descriptive matter from my patent are incorporated into this application by reference, and since the patent is available to the public, a detailed description of the generalized construction of the floating roof will not be made.

FIG. 1 illustrates a portion of the floating roof which is indicated generally by the numeral 10, and the corresponding construction of the fixed roof is indicated by the numeral 12. The base of the tank is indicated by 18 and the fixed roof by the numeral 32. The floating roof 10, of which a portion is shown, is constructed with a plastic and fiberglass bottom sheet 20 on which is applied a foam plastic layer 22.

A plurality of tension members 24 are applied in an aerial distribution over the floating roof, only one of which is shown. This tension member 24 is supported from the fixed roof by extending; up through the roof through an opening 36, where the end of the member is attached by clamp 42 to a cover 38. The cover effectively seals out the dirt and weather from the tank which might pass through the opening 36. This seal is facilitated by a plate 34 which provides a lip seal at the bottom of the cover, but also provides a means of strengthening the roof at that point.

The lower end of the tension member 24 is supported by a loop or eye 26 which is attached by rod 28 to a pressure plate 30 underneath the bottom of the floating roof, which serves to spread the force of supporting the roof over an appreciable area. The area shown may not be mechanically adequate, but does illustrate the use of the supporting flange 30 to support the roof from the eye 26, which is itself supported by the cable 24 from the roof 32. For the lowest position of the roof, the tension member will be stretched taut from the clamp 42 through the opening 36 to the eye 26. When it is desired to support the floating roof at another higher position, liquid is pumped into (or is already pumped into) the tank and the floating roof, floating on the liquid, and is then at an intermediate or upper position, indicated generally by the dashed line 19, in which case the tension member 24, which may be a cable or chain or the like, is slack. The cover 38 can be lifted from the roof by means of handle 40 and put aside so that a clamp 44 can be applied to the member 24 at a point where it will be essentially taut between the clamp 44 and the floating roof, which is now supported by liquid. A washer 46 is used so as to prevent the clamp 44 from passing down through the opening 36. The extra loop of tensile member 24 can be coiled up inside of the cover 38 and the cover can then be replaced.

With the floating roof at position 119, if the liquid is pumped out of the tank so as to make the bottom portion of the tank available for cleaning, the floating roof will be supported at the position 19 by means of the cable or chain 24 which is clamped by means 44.

By the use of the movable clamp 44 it is seen that the tank roof can be supported at any desired level by simply shifting the clamp. There may be some reason why a preselected level of position of the floating roof is desired. In this case a loop can be prepared in the cable, or the chain, which is illustrated schematically by the loop 68 formed in a cable 24 by means of a cable clamp 76 The upper end of the cable 24 is fastened to an eye 64 in a bolt which is supported by nut 66 attached to the cover 58 of the roof fixture indicated generally by the numeral 14.

In this embodiment of FIG. 2 the roof is provided with a larger opening 49 and can be strengthened over the region of the opening by means of a pressure plate 34 which spreads the force over a large area of the roof. Also, it is desirable to provide the opening 49 in the proximity of a stiffening rib or other support in the fixed roof. The opening 49 is covered by means of a flanged section of pipe 50, which has a bottom flange 52 by means of which it is bolted to the fixed roof, by means of bolts 56. There is a cover 58 which fits over the upper flange 5d, and rests on an inner flange 62 so that the sidewall 60 hangs below the flange 54 and provides a good shield against rain and weather. Assume again that the floating tank roof is at position 19 and the cable 24 is slack, the cover 58 can then be lifted off by means of handle 40 and the loop 68 will now be in the slack portion of the cable and can be hooked over the hook 72 and the cover replaced. Now as the liquid drains out of the tank and the floating roof tends to lower, the support member 24 will become taut and the level of the floating roof will then be determined by the length of cable between the loop 6%} slipped over the hook 72, and the floating roof will be supported at that point.

It is clear that a plurality of such loops can be used at different positions along the tensile member 24. These loops can be provided in cable as shown or can be rings inserted into links of a chain and so on.

FIG. 3 shows a slight variation of the system of FIG. 2. It can be applied also to the system of FIG. 1. This involves the use of a short bar or channel 80, supported on the interior of the pipe 50 such as by welding or bolting, not shown. The tensile member 24 is attached to the eye 64 which is bolted to this crossbar 80 thus securing the cable 24 directly to the fixed roof 32 instead of the cover 58 so that the cover 58 is now free of connection with the cable 24 and can be placed on or removed from the roof as desired. The use of the bar provides easy access and inspection of the situation and still provides a good support for the upper end of the tension members 24.

While the invention has been described with a certain degree of particularity it is manifest that many changes may be made in the details of construction and the arrangement of components. It is understood that the invention is not to be limited to the specific embodiments set forth herein by way of exemplifying the invention but the invention is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element or step thereof is entitled.

What is claimed:

1. In a fluid storage tank having a fixed roof at the top of the tank and a floating roof inside the tank, the improvement comprising means to independently support said floating roof from said fixed roof at at least one vertically spaced intermediate position between the uppermost and lowermost positions thereof and comprismg;

a. a plurality of spacially distributed openings in said fixed roof;

b. a plurality of supportfastenings on said floating roof each substantially in vertical alignment with a respective one of said openings;

c. a plurality of flexible tension members, each attached at its lower end to one of said fastenings and extending vertically upward to its said respective opening; and

d. means engagable with said tension members to support said tension members adjustably from said fixed roof for positively securing said floating roof in any of said vertically spaced intermediate positions independent of the level of the fluid in the tank.

2. The support system as in claim 1 in which said tension members are supported directly from said fixed roof.

3. The support system as in claim ll in which said tension members are attached at their upper ends to removable covers which are supported by said fixed roof on said openings.

4. The support means as in claim 1 in which said tension members comprise cables.

5. The support means as in claim 1 in which said tension members comprise chains.

6. The support means as in claim 1 in which said tension member has at least one loop attached at a point intermediate its lower and upper ends, and including means to attach said loop to said roof.

Claims

1. In a fluid storage tank having a fixed roof at the top of the tank and a floating roof inside the tank, the improvement comprising means to independently support said floating roof from said fixed roof at at least one vertically spaced intermediate position between the uppermost and lowermost positions thereof and comprising; a. a plurality of spacially distributed openings in said fixed roof; b. a plurality of support fastenings on said floating roof each substantially in vertical alignment with a respective one of said openings; c. a plurality of flexible tension members, each attached at its lower end to one of said fastenings and extending vertically upward to its said respective opening; and d. means engagable with said tension members to support said tension meMbers adjustably from said fixed roof for positively securing said floating roof in any of said vertically spaced intermediate positions independent of the level of the fluid in the tank.

3. The support system as in claim 1 in which said tension members are attached at their upper ends to removable covers which are supported by said fixed roof on said openings.