RU2524329C2 - Full-contact pontoon for tanks with volatile oil products - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil industry and can be used in oil and oil products storage tanks. Proposed pontoon consists of central and peripheral hollows boxes with omega-shape slots made along edges to be assembled inside cylindrical ring by fitting eight-shape lock in said slots, this lock being provided with smooth boss arranged at its centre. Central boxes feature rectangular shape in plan while peripheral boxes - trapezoidal shape. Corner incisors shaped to circular truncated segment are arranged between peripheral boxes and ring. Retainers in said omega-shape slots can displace. For this they are furnished with smooth bosses made over the entire length.

EFFECT: sufficient stiffness and strength, no need in extra connectors nor bearing elements.

2 cl, 8 dwg

Description

The invention relates to the oil industry and can be used in enterprises having vertical cylindrical tanks for storing oil and oil products.

The surface of the volatile oil product in the tank is isolated from atmospheric air using a floating coating called a floating roof in open tanks and a pontoon in covered tanks. In many countries, including Russia, this has become an obligatory norm, because thanks to these coatings, along with oil product savings, air pollution is prevented and the risk of fires is reduced.

There are float and full contact pontoons. A pontoon is called a float, the buoyancy of which is provided by floats immersed in liquid no more than 50% of their height. Between the surface of the oil product and the pontoon deck there is a space filled with a vapor-air mixture. A hydraulic lock is located around the perimeter of the pontoon, which prevents the escape of gas from under the pontoon. The bottom floor of the full-contact pontoon after its ascent lies on the oil product, there is no gas space under it. These pontoons perform the same function: they significantly reduce losses from the evaporation of the oil product, but cannot completely prevent them, since they have a valve around the perimeter through which the vapor of the oil product flows into the over-pontoon space and from there into the atmosphere.

Known full-contact pontoons of the cup type, pontoon and two-layer / 1, 2 /. These pontoons, usually steel welded, are welded inside the tank, which is their drawback, in addition, they have a large mass, require good corrosion protection.

Known full-contact pontoon, filled from the inside with a honeycomb structure, is a sealed one-piece panel / 3 /. Such non-assembled and non-welded pontoons can only be used in small-sized open tanks, and the diameter of oil tanks with a pontoon reaches 60 m or more.

A well-known tank with a floating block coating, consisting of blocks in the form of boxes of sheet material filled with polymer foam / 4 /. The blocks are fixed in rows on the longitudinal beams, the beams are fastened with transverse ties. This coating is also a full contact pontoon. The advantage of this pontoon is its blockiness. Its disadvantages: the presence of beams and screeds, since the boxes are not bearing; polymer foam filling the boxes nevertheless absorbs the oil product and its vapors, is saturated with them in case of violation of the tightness of the shell of the boxes made of sheet material, and this creates a hidden fire and explosion hazard of the boxes. In addition, polymeric foam, especially saturated with petroleum products, is difficult to recycle; it is forbidden to take them to garbage dumps; when it is burned, toxic and poisonous substances are formed. This is one of the closest analogues of the pontoon proposed in this application.

In the proposed design, the full-contact pontoon is assembled from central rectangular and peripheral trapezoidal ducts having an internal lattice or honeycomb structure, fastened together and forming a continuous coating on the surface of the liquid, peripherally framed by a cylindrical rim, the lower edge of which is located below the waterline of the pontoon, is fixed on the upper edge gate. The central boxes are located along the chords of the circle, the peripheral boxes are arranged around the circumference, circumferential segments are located between the peripheral boxes and the rim, the boxes have omega-shaped profile grooves along the longitudinal edges, a cap is also fixed at the ends with omega-shaped profile grooves, adjacent boxes are fastened together by means of a retainer having an octal shape in cross section, provided with a tide in the middle along the entire length, the retainer can move in an omega-shaped groove.

The combination of the structural forms of the elements of the pontoon, their relative position allows for quick assembly of the pontoon without the use of bolted and welded joints. The pontoon can also be quickly disassembled, ensuring the safety and performance of all its elements. It is enough to remove one of the extreme boxes to completely disassemble the pontoon (and if necessary, assemble it back). Having hooked on the tide with a probe, the latch can be moved in an omega-shaped groove, and if necessary, removed. So, box after box is the assembly and disassembly of the pontoon. In the working position, the bottom surface of the pontoon is completely in contact with the oil product; there is no gas space between the pontoon and the surface of the oil product. Due to this, the proposed pontoon is highly effective in reducing losses from the evaporation of oil during storage and technological operations.

Figure 1 - tank, inside which the pontoon is located.

Figure 2 - pontoon in plan.

Figure 3 - box with omego-shaped grooves at the edges.

Figure 4 is a box with plugs inserted at the ends.

Figure 5 - eight-shaped retainer with the tide.

6 - the location of the support pontoons.

7 is a fringe.

Fig - connection of adjacent boxes in the assembly.

In the tank 1 there is a pontoon 2, which consists of boxes 3 and 4, at the edges of which there are omega-shaped grooves 5, at their ends are plugs 6 with omega-shaped grooves, adjacent boxes are interconnected and fastened using eight-shaped clamps 7, in the middle of which a smooth tide is arranged along the entire length 8. A rim 9 is located around the perimeter of the pontoon, on which a shutter 10 is mounted, which contacts the tank wall.

The peripheral boxes are trapezoidal, and the rim is cylindrical. In the space between the rim and the peripheral boxes installed edges 11 having the shape of a truncated circular segment. Boxes have an internal lattice or honeycomb structure to ensure their strength and rigidity. In the omega-shaped profile groove in the middle there is a semi-cylindrical groove 13 into which an elastic seal 14 is installed. The liquid level 15 in the tank is located above the lower edge of the rim to form a water seal. In the lowermost position, the pontoon rests on the support posts 16, located evenly over the entire area of the pontoon.

The proposed pontoon works as follows. When filling the tank with oil product, the pontoon floats on the surface of the oil product due to the lifting force of all its boxes. The support legs move with the pontoon. A sealing shutter slides along the inner surface of the tank wall, isolating the surface of the oil from atmospheric air. The lower part of the rim is immersed in the oil product, so the steam-air mixture that can form under the flooring cannot move into the gate space.

When emptying the tank, the pontoon in its lower position sits on the support posts, which absorb the weight of the pontoon and the external load. The external load is created due to the weight of the liquid that has fallen onto the pontoon floor (condensate or the ejection of liquid onto the pontoon through the gate due to turbulence or impact of gas plugs). To drain this fluid in the pontoon provided drainage.

All boxes have sufficient strength and rigidity due to their size, shape and internal structure. Therefore, this pontoon does not require any additional elements such as beams, ties or screeds to ensure its strength and rigidity. The dimensions of the boxes are selected based on the technological capabilities of the manufacturer and the size of the manhole in the first zone of the tank. Thanks to this, all pontoon boxes are unified for tanks of various diameters. Having outlined a circle of a larger or smaller size on the pontoon in plan in figure 2, you can get a finished plan of the pontoon of various diameters.

Information sources

1. Fathiev N.M. Operation of tanks with a floating roof. Thematic review, TsNIITEneftekhim. M., 1991.

2. United States Patent 2586856. Dauble - Deck Floating Roof. Cl. 220-26.

3. Patent for utility model No. 78176. A floating roof tank for storing liquids.

4. Patent for invention No. 2364561. A tank with a floating block coating for technological operations with oil or oil products.

Claims (2)

1. Full-contact pontoon for tanks with volatile oil products, consisting of central and peripheral boxes filled inside with honeycombs or ribs, fastened together and forming a continuous coating on the surface of the liquid, peripherally framed by a cylindrical rim, the lower edge of which is located below the waterline of the pontoon, central and peripheral supporting racks, characterized in that the central boxes are located along the chords, the peripheral ones are circumferentially located between the peripheral boxes and the rim oraichki in the form of a circular truncated segment, box along the longitudinal edges have an omega-shaped profile groove, plugs are also installed at their ends with an omega-shaped profile groove, adjacent boxes are interconnected and fastened using clamps having an eight-shaped cross section and in the middle provided with tides along the entire length, with a possibility of movement of clamps in an omego-shaped groove. 2. Full-contact pontoon for tanks with volatile oil products according to claim 1, characterized in that the central boxes are rectangular in shape, and the peripheral ones are trapezoidal.

Images