HU209460B - Storing container for liquefied gases - Google Patents

Abstract

Storage tank for liquefied gas intended to be buried, including a vessel (2) coated on its external wall with an anti-corrosion coating covered at least partially by matting (4) formed by a double-walled textile consisting of two textile webs joined together by a plurality of transverse linking threads, the space between the two textile webs being filled by a particulate material having heat-transfer properties similar to those of the ground. <IMAGE>

Description

The present invention relates to a storage tank for liquefied gases to be embedded in the ground.

It is known that, for both safety and aesthetic reasons, storage tanks for liquefied gases, such as propane and butane, used for both domestic and industrial purposes, are preferably embedded in the ground. Containers currently used for this purpose generally have a cylindrical container body, the ends of which are essentially closed by ball-shaped fittings. In addition, these container bodies are protected against corrosion by a polymeric coating associated with a cathodic protection system containing a magnesium protective anode. Containers of this type are most often approx. They are 1 m in diameter and 3 m, and sometimes 4-6 m long, and are embedded in ditches where the excavated volume is almost 15 m ^{3 for} a 3 m long tank body. After such a container body has a volume of approx. 3 m ³ , so about 12 m ^{3 of} land needs to be replenished. Unfortunately, it is generally not possible to recharge from the excavated earth, since the coarse pebbles and rock fragments it contains may damage the protective coating, which can lead to subsequent corrosion of the tank body. For safety reasons, sanding must be carried out. Thus, 12 m ^{3 of} sand must be retrieved and 15 m ^{3 of} earth must be transported, which leads to increased costs for each storage tank installation.

One of skill in the art would undoubtedly have thought of protecting the container body's anti-corrosion protective coating by using an external, impact-resistant, prop-like casing; here, however, it should also have been ensured that this pumice-like casing (hereinafter referred to as "peacock" casing) would provide sufficient heat transfer, similar to the fill sand used to date. In fact, when gas is removed from the container body, the liquefied gas evaporates and thus the storage container cools down. In order to avoid an excessive reduction in the vapor pressure of the gas, which may even lead to a disruption of the gas supply provided by the tank, when the gas pressure is no longer sufficient to compensate for the distribution pressure losses, it is imperative that the heat exchanger of the tank body is sufficiently intense. Thus, one skilled in the art was aware of the fact that he would not be able to use traditional coverings for impact protection, such as expanded polystyrene or glass wool, whose thermal insulation properties were too high to solve the above problem. Thus, in order to solve the above problem, it was necessary to develop, instead of the conventionally used sheaths, a shockproof sheathing which at the same time provides sufficient heat transfer to prevent the gas from cooling too much during the gas uptake.

Double-walled textiles, such as the French publication "Textiles á usage technique" (Trimester 4, No. 2, pp. 25-27, 1991), provided a good basis for this new type of blanket cover. page). This fabric, the walls of which are formed by a plurality of transverse filaments (about 40,000 pc / m ² ), formed by two textile braids, can be used, for example, to produce synthetic liners where the transverse fibers between the two braids are cut in their middle region. lining the fluff. It has also been proposed to use this fabric for the flooring of inflatable rubber boats, where each shell is airtight and the space between the two shell with inflatable air to form a light planar structure with excellent rigidity.

According to the present invention, this type of fabric, where the fibers connecting the two textile coats are not cut but the interior space between the two coats is filled with fine particles having heat-transfer properties similar to the ground, is well suited for encapsulating underground storage containers, fabrics such as polypropylene are used.

The present invention thus relates to an underground storage tank for liquefied gases having a container body with an anti-corrosion coating on its outer walls, characterized in that the coating is at least partially covered with a planking formed by a double-walled fabric, they are interconnected by transverse strands to maintain the shape of the sheathing, and the interior space between the two textile sheaths is filled with fine particles having heat transfer properties similar to those of the ground.

In accordance with the present invention, in order to preserve the heat transfer characteristics of the previously used earth-embedded structures, the space between two coats is filled with a fine-grained material having heat transfer properties similar to those of the soil such as sand, silicate, mica, clay beads, glass beads. It is particularly advantageous to use sand for this purpose since it is a readily available and inexpensive material; otherwise, light sand, such as expanded clay sand, should be used for ease of use.

Once the double-walled fabric is filled with fine-grained material, the transverse interconnecting fibers hold the two textile edges substantially parallel, thereby obtaining sufficiently flexible flat spheres that are able to conform to the shape of the container body wall and allow good thermal contact with the container.

According to a variant of the storage container according to the invention, the sheathing can be adapted to the shape of the container body, thereby forming a shockproof protective cover over the entire wall of the container body. Preferably, the panel cover is formed from a plurality of substantially mating flat cushion bodies where the joining zones between adjacent panel members do not significantly reduce heat transfer. The individual body members may engage with each other by any known means such as straps, hooks or straps.

It is known to install storage tanks of this type2

EN 209 460 B, the container body is placed in a trench of sufficient size, whereby the container body is placed at the bottom of the trench by inserting a support saddle bed, which usually consists of prefabricated concrete elements arranged side by side along the longitudinal axis of the tank body. According to the invention, the container body already coated with the sheath is placed on the support saddle bed. The support saddle bed is provided with at least one cutout in which the protective anode of the cathodic protective system can be arranged.

According to a preferred embodiment of the invention, the body of the container having the head cover and the support saddle bed is covered with a textile cover, preferably a non-degradable textile cover made mainly of polypropylene; this casing mechanically connects the container body to its support saddle bed. While the container body is formed as a cylindrical container body enclosed by two spherical shapes, the interconnecting shell is formed as a generally cylindrical, loop-like formation closed by longitudinal welding or suture; thus, the open transverse ends of this envelope may be clamped to adhere at least partially to the transverse ends of the container bodies covered with a cushion cover; in fact, the open ends of the shell may be provided with a loop edge through which a string or rope can be slipped through to allow the aforementioned clamping. The mechanical connection between the container body and the support saddle bed allows the body to be loaded and held in the ditch even when the underground support is raised, and the buoyancy acting on the body remains less than the weight of the support member.

In this preferred embodiment, the lifting means are secured to the housing, for example, by means of metal bars, one or more cables or one or more ropes, preferably one or more reinforced areas, so that the container body can be appropriately lifted for relocation, transport, or remove it from the ditch. Preferably, the reinforced regions are formed in pairs and arranged symmetrically with respect to the longitudinal center plane of the container body. The one or more reinforced regions may also be formed from one or more webs slid under the support saddle bed. In the latter case, the reinforced region may be formed by a sleeve through which a cable is passed through a rope. In this way, it can be prefabricated in a joint operation consisting of a tank body, a support saddle bed and a shell with a shield cover. The container body is thus protected during storage and transport; the cathodic protection electrodes, which are also contained within the housing, are also protected.

When the storage tank arrives at the installation site, it can be easily placed in the prepared trench, while the concrete support saddle bed as a weight allows precise positioning. In addition, it is possible to bury the trench with the earth removed from it, as the anti-corrosion coating is protected by the sheathing and the cover. In this way, only one volume of land that is equal to the volume of the storage tank remains, for example, for a tank body of 1 m diameter and 3 m long, approx. 3 m ³ , which is usually distributed on site.

According to a second embodiment of the storage container according to the invention, the anti-corrosion coating is covered on both ends of the container body with a felt-lined knitted cap and at least on the underside of the cylindrical portion of the container body on the upper half of its cylindrical part.

Preferably, the cushion cover consists of two cuffs and metal rods disposed in the curbs adjacent to their cutout edges, where the cutouts allow for fastening or securing straps on the metal rods.

Preferably, a tissue blanket surrounds the cylindrical portion of the container body, thereby covering the felts and the pillow cover.

Preferably, the storage container is covered by at least one anchoring saddle so that the length of this anchor saddle is selected such that when the storage container is placed in the ditch, the spreading saddle covers not only the upper cylindrical portion of the storage tank but and the wall facing this upper cylindrical portion, which is secured when covered with buried earth, thereby also making the storage tank heavy.

In one preferred embodiment, the aforementioned joint straps are held together by the stabilizing wedges; preferably, the straps are fastened at one end to rods pierced through the loop edges of the anchoring sheet (or sheets) forming the anchoring saddle (s).

The invention will be described in more detail in connection with two embodiments, based on the accompanying drawings.

In the drawing it is

Figure 1 is a vertical longitudinal sectional view of a storage container according to the invention, a

Figure 2 is a cross-sectional view of the storage container of Figure 1, a

Fig. 3 is a perspective view of a container body having a shield cover, a

4-9. Figures 6 to 8 are perspective views of a variant of a storage container according to the invention in successive phases of implementation;

10-13. Figures 4 to 9 are half-sectional views; Figs.

The entire container of the invention is designated by the reference numerals 1 in the figures. 1-3. 1 to 4, the storage container 1 consists of a metallic container body 2 having a cylindrical 2a.

460 Β and this cylindrical part 2a is closed at each end by an outwardly projecting, essentially spherical shaped part 2b. The outer walls of the container body 2 are provided with an anti-corrosion coating containing polymers. The container body 2 may be, for example, 1 m in diameter and 3 m long; the empty weight thus weighs about 0.5 tons. As shown in Fig. 1, the upper part of the container body 2 is provided with a valve 3 and a reducer (pressure relief device). The container body 2 is surrounded by a sheath 4 which, as shown in Fig. 3, consists of eight matching shells which together cover the entire container body 2. Four of the eight cushion bodies are lateral 1 la cushion bodies, two are upper 1 lb cushion bodies, and two are extreme 11c cushion bodies. The side bodies 11a also cover the lower part of the body 2 of the container. Each of the base bodies 11a-11c is made of a double-walled fabric which is filled with light sand and, after filling, has a size of about 20 cm. 4.5 cm thick. The light sand used is swollen clay sand which is approx. Provides a load of 30 kg per 1 m ^{2 of} cushion cover, making it easy to move the cushion bodies. Double-walled linen is approx. It contains 40,000 transverse strands that connect the two sheaths forming the boundary. These body members are joined by any known means, such as straps or straps, so that they are pressed against the walls of the container body 2.

The container body 2 with a shield cover 4 is mounted on a support saddle bed 5 consisting of precast concrete elements arranged side by side and interconnected. This support saddle bed 5 has a trough shape and its bottom is flat to lie on the bottom of the trench for receiving the storage container 1, but has a cut-out portion which is in contact with the support body 4 of the container body 2 and is circular in cross-section. A longitudinal cut is provided in the sidewall of the support saddle bed 5 to receive a protective anode 6 made of magnesium material.

The assembly of the container body 2, the shield cover 4 and the support saddle bed 5 is encased in a cover 7 made of polypropylene fabric, which has the advantage that it does not decompose. This casing 7 is closed at the side by stitching and has a generally cylindrical shape. The shell 7 is clamped at each end by a string 8 which is pierced by an attached loop rim or sleeve near these ends, even in a marine bag, to accommodate the spherical ends of the padded container body 2. The ready-to-install configuration of the storage container 1, which includes a container body 2, a quilt cover 4 and a cover 7, allows for a quality of workmanship that is not affected by site conditions.

The casing side 7 is provided with two reinforced regions 9 for securing a cable 10 which allows lifting means to pass through to raise the ready-to-use tank body and to insert it into a prepared ditch. Next, we ensure that the storage tank is connected to your distribution system via the structure 3. When the storage tank has been repaired, the trench is buried by a machine, without special precautions, using the earth mass produced in the trench.

4-9. Figures 1 to 5 show another possible embodiment of the protective cover of the storage container according to the invention. The structure of this shield will be better understood by presenting successive phases of implementation. A storage rack 21 is used to form the reservoir, which facilitates the positioning of the various structural members of the guard. The metal mounting saddle 21, which has a general shape resembling a semi-cylindrical trough with a flat bottom to lie firmly on the ground, has a length that is slightly less than the length of the storage container to be protected. The semi-cylindrical wall of the mounting saddle 21 is provided with two pairs of rectangular cutouts 35 extending symmetrically on both sides of a longitudinal axis from the longitudinal axis of the mounting saddle 21; some of these cut-outs 35, whose function is described below, are well illustrated in Figures 7 and 8.

First, the container body 20 of the storage container 1, the outer walls of which are provided with a polymeric anticorrosion coating, is coated at each end with caps 27A and 27B of knit fabric, the knit fabric consisting of a polypropylene web wrapped with synthetic fibers, the circular portion as well as the cylindrical portion and the weight of this felt in this example is 2.5 kg / m ² . Each of the caps 27A, 27B covers the substantially spherical end and partially the cylindrical portion of the container body 20 as

As shown in Figure 4. Figure 4 also shows that a knitted fabric cover 27 is initially laid on the mounting saddle 21 with a material similar to that of the caps 27A, 27B, which in this example consists of two parts sewn together and has a length equal to the length of the container body 20. slightly smaller than the circumference of the container body 20 such that, when the knitted fabric cover 27 is placed on the mounting saddle stand 21, it covers the underside of the trough-shaped portion of the mounting saddle stand 21 and its edges lie down on both sides of the mounting saddle stand 21.

In a next step, two adjacent collars 24A, 24B of the panel cover are formed similarly to those of Figures 1-3. 4A, disposed on the fabric cover 27 along its length so as to cover the side up to the height of the longitudinal straight edges of the trough-shaped portion of the mounting rack 21. Metal bars 23 are disposed near their longitudinal side edges in the jacket 24A, 24B. These lateral edges are provided with cut-outs that allow the straps 25 to be secured to the metal bars 23, where the straps 25 are used to move and suspend the collars 24A, 24B as shown in FIG.

EN 209 460 Β as they will be seen in a later phase. In the phase shown in Figure 5, the straps 25 are prepared to perform the aforementioned function.

In a third step, the container body 20 is placed on the previously prepared mounting saddle rack 21 and a blanket 22 is laid over the top of the container body 20, the material of which is similar to that of the aforementioned felt but has a surface weight of only 1.2 kg / m ² . This felt jacket 22 has a rectangular aperture 36 in the center thereof extending through the organs of the gas removal device 3 and extending transversely to the longitudinal edges of the trough-shaped portion of the mounting saddle rack 21. The opposing straps 25 are then joined together to form the state shown in Figure 6. In a fourth step, a second felt jacket 26 is provided on top of the container body 20, having the same material and size as the felt jacket 22, but heavier, for example, with a surface weight of 2.5 kg / cm ² . The tissue blanket 27 is then raised on both sides of the container body 20 to enclose the container body 20 therewith. The blanket 26 is clearly shown in Figure 7, where the edges of the fabric cover 27 do not touch. The entire assembly is joined by two pairs of straps 55, where each pair of straps is facilitated by rectangular cutouts 35 formed in the mounting saddle 21 through which the respective strap pair passes. The straps 55 also fasten, for example, wooden wedges 45, perpendicular to each of the four cutouts 35. The wedges 45 ensure the stability of the storage tank on the ground and at the bottom of the storage tank receiving trench when the finished storage tank is pulled off the mounting rack 21. The wedges 45 and the recesses 35 are dimensioned and shaped such that when the ready-assembled container assembly is lifted vertically from the mounting saddle 21, this operation can be performed without difficulty while the mounting saddle 21 remains on the ground. Preferably, at least one of the wedges 45 carries a protective anode. Before raising the container, anchor anchor saddles 28A, 28B of polypropylene are placed on the storage container. Each saddle blanket 28A, 28B is in fact a strip of width that covers the storage container from its end to the opening 36 and has a length such that the end of each strip tapes to the ground. For transport to the ditch, the edges are rolled up for use, as shown in Fig. 9 in the example of a saddle blanket 28A. In this figure, the storage tank is shown in an upright position, outside the mounting saddle 21, while the protective cover 3 of the gas removal device 3 is already mounted thereon. The storage tank so equipped is now ready to be placed in the ditch. Preferably, in this example, the straps 55 are fastened at one end to rods 53 threaded through the loop edges of the shroud 28A, 28B as shown in Figure 8.

10-13. Figures 6 to 9 are half-sections showing successive phases of the storage tank trenching. Inside the trench 30 is placed a storage tank fitted as described above. The stable position of the inserted storage container is provided by the wedges 45, which are not shown in these figures. In the trench 30, a first filling 31 is first placed next to the container body provided with a protective cover, approximately half the height of the storage container. The anchor saddle covers 28A, 28B are then spread so that they cover the filling 31 and extend upwardly along the wall of the trench 3 to its full height, which is then secured to the wall, for example by means of nails 29. A second .32 filling is then added to the top of the saddle covers 28A, 28B so as to completely cover the container body of the storage container.

A safety metal grid 33 is then laid and covered with a final charge 34. It will be noted that due to the presence of the anchor saddle covers 28A, 28B, the fillings 32 and 34 load the storage container with sufficient weight.

Claims (13)

PATENT CLAIMS An underground storage tank for liquefied gases having a container body with an anti-corrosion coating on the outer walls of the storage tank, characterized in that the coating is at least partially covered with a planking (4) formed by a double-walled fabric, (4), and the interior between the two textile sheaths is filled with fine particulate material having heat transfer properties similar to those of the ground. Storage container according to Claim 1, characterized in that the space between the two textile surfaces of the double-walled fabric is filled with sand. Storage container according to Claim 1 or 2, characterized in that the sheath (4) is formed of a plurality of flat shells (11a, 11b, 11c). Storage container according to Claim 1 or 2, characterized in that the container body (2) wrapped with the sheath (4) is mounted on a support saddle bed (5). Storage container according to Claim 4, characterized in that the support saddle bed (5) is provided with at least one cut-out including the protective anode (6) of the cathodic protection. 6. Storage container according to one of claims 1 to 3, characterized in that the wrapped container body (2) and the support saddle bed (5) are enclosed in a housing (7) mechanically joined thereto. 7. Storage container according to any one of claims 1 to 3, characterized in that the double-walled fabric of the main cover (4, 24A, 24B) is a non-degradable fabric, preferably polypropylene. 8. Storage container according to any one of claims 1 to 4, characterized in that the anti-corrosion coating is covered on one end by a knitted fabric cap (27A, 27B) at each end of the container body (20). A fabric padded inside with a felt and on the other hand with a cushion cover (24A, 24B) at least on the lower half of the cylindrical part of the container body (20) and two felt wraps (22, 26) on at least the upper half of the cylindrical part . Storage container according to Claim 8, characterized in that the sheath (24A, 24B) consists of two collars (24A and 24B), in which the collars are provided with metal bars (23) near their lateral edges, wherein the lateral edges are for hanging and securing straps (25). ) are provided with cut-outs allowing their attachment to said metal bars (23). Storage container according to claim 8 or 9, characterized in that the cylindrical part of the container body (20) is surrounded by a fabric cover (27) covering the felt wraps (22, 26) and the cushion cover (24A, 24B). 11. Storage container according to any one of claims 1 to 4, characterized in that it is covered by at least one anchoring saddle cover (28A, 28B), the length of the saddle cover (28A, 28B) spreading over the upper cylindrical portion of the storage container and cover the spreading saddle blanket (28A, 28B) by at least one filling (32, 34), while also constituting the weight of the storage tank. 12. A11. Storage container according to claim 1, characterized in that the wrapped container body (20) is supported by stabilizing wedges (45) and is surrounded by fixing straps (55). Storage container according to claim 12, characterized in that the straps (55) are fastened at one end to rods (53) threaded through the loop edges of the cover (or sheets) forming the saddle cover (28A, 28B).