EP0003938B1 - Container with a high security level. - Google Patents

Description

The present invention relates to a container with a high degree of security, intended in particular for dangerous products or installations.

Increasingly, under the pressure of public opinion and the bodies responsible for public security, an ever higher degree of security is sought in the storage of dangerous products, so as to separate them from the environment and protect them. external aggressions. These products can in particular be liquids such as natural gas. ammonia, vinyl chloride, hydrocarbons.

Far from constituting only simple means of storage, the containers used for this purpose must now be able to withstand fire, sabotage, for example rocket fire, even plane shocks, earthquakes. and similar attacks.

FR - A - 977 666 describes different types of tanks, for all gases or liquids, in particular for hydrocarbons. FIG. 1, in particular, shows a tank in two parts, suspended from a belt, itself resting on an external support base by means of elements allowing the expansion of said belt. However, the annular space between the tank and the external support base is empty and the bottom of the tank rests freely on the horizontal support base. As a result, the side walls of the tank are poorly protected against external impact or projectile fire; on the other hand, the tank is not very stable with respect to lifting by hydrostatic thrust, especially if it is empty; finally, in the event of an earthquake, the elements through which the tank belt rests on the external support base do not appear capable of opposing overall movements of the tank, that is to say that is to say large-scale slippages from the bottom of the tank to the horizontal base.

DE - A - 2 054 962 describes a fully buried receptacle for the storage of explosives. Because it is fully buried and its external side walls are therefore neither exposed to external shocks nor to direct fire from projectiles, these can be formed by a stack of hollow and easily destructible rings, that is ie with relatively low mechanical resistance; these outer walls only have the role of opposing the collapse of the walls of the excavation. Likewise, the annular gap between the outer walls and the storage tank itself is filled with plastic foam, which obviously has no effect either of mechanical protection or of increasing the stability of the container vis-à-vis -vis an uplift by hydrostatic thrust, since the plastic foam is not very resistant and very light. Of course, in the event of an earthquake, the various walls of this storage receptacle could be crushed due to their fragility.

LU -A - 33 496 shows in its figure 14 a double-walled container for liquids, other products or biological installations; the space between the two walls can be left empty for air circulation, or filled locally with a layer of insulation or concrete (figure 9). In fact, the description of the container illustrated in Figure 14 is entirely insufficient to allow those skilled in the art. not even to realize it, but only to assess whether its structure gives it a high degree of security, especially in the event of an earthquake.

The object of the present invention is in particular to create a container which makes it possible to resist the various attacks mentioned above. It should also be considered that this container can not only be intended for the storage of products or materials, but also to enclose particularly dangerous or delicate installations, such as nuclear reactors or chemical reactors.

The container which is the subject of the invention comprises a tank which rests, by means of supports allowing expansion, on a continuous and watertight foundation, providing an aeration space under said tank, said foundation continuing with an external wall. , delimiting an annular space around the tank. This container is characterized, according to the present invention, in that said annular space is lined with a filling which contributes to ensuring the stability of the container with respect to lifting by hydrostatic thrust even when the container is empty, and to protect the container against external shocks or projectile fire, and that the lower edge of the tank rests on the foundation by means of keys preventing the overall movement of the tank relative to the foundation while allowing expansion of the tank.

By "overall displacements of the tank" is meant its large amplitude displacements, relative to the foundation; such overall displacements can be produced for example by an earthquake and they must be clearly distinguished from the local displacements of the various elements of the walls of the tank, which are due to thermal expansion.

Advantageously, ventilation is provided in the aeration space intended in particular to maintain a determined temperature, for example in order to avoid freezing of the floors in the case of liquefied gases at low temperature, to avoid the accumulation of dangerous gases or to allow control of the sustainability of the foundation.

The container is preferably made of concrete, reinforced or prestressed according to the specific cases, the rates of work and the conditions of safety. It can receive very large dimensions.

The description which follows with reference to the appended drawings, given by way of nonlimiting example, will make it clear how the invention can be implemented.

Figure 1 is a partial schematic view in vertical section of a container according to the invention; Figure 2 is a partial couple view along II-II of Figure 1; in Figure 3 is a detail section along III-III of Figure 2; Figure 4 is a schematic vertical section showing the principle of ventilation of the container; Figure 5 is a partial vertical section of a variant having an outer wall molded into the ground; Figure 6 is a very partial schematic vertical section of a second variant comprising a lower support slab; Figure 7 is a similar view of another variant having an upper deck.

In FIGS. 1 to 4, the container comprises a foundation constituted by a dome or bowl 1, the concavity of which faces upwards. In the present example, this dome is circular but the shape of its perimeter could be different.

The marginal portion 2 of the dome 1 is reinforced and connected to a vertical external wall 3, in the present cylindrical example, the whole is buried in the ground 4 at a depth which can be arbitrary.

On the dome 1 are provided pillars 5 distributed in concentric circles as shown in Figure 2 and intended to support a slab 6 which can be planar. Between the slab 6 and the dome 1 is formed a space 7 intended to isolate the inner tank of the container from possible infiltration of water from the groundwater 8. Water penetrations would in particular be harmful if refrigerated gases were stored in the container.

The slab 6 is integral with the side wall 9 of the tank, a wall which is parallel to the external wall 3, an annular space 10 being formed between the two walls.

The lower part of this space 10 forms a visit and ventilation gallery delimited at its upper part by a ceiling 11 (FIG. 1 For the rest, the space 10 can be filled with a filling 12 which can be: a pulverulent material such as sand to provide protection against external impact or projectile fire; lean concrete, especially if the container is to be grounded. In this case, a slight space must be left between the lean concrete and the exterior wall 3 to allow drainage and ventilation.

The dimensions of the space 10 and of its lining are chosen in such a way that the safety criteria with respect to external shocks are respected and that the stability with respect to a lifting by hydrostatic thrust is ensured even when the container is empty.

The internal side wall 9 continues with a dome 13 which can receive, like the space 10, a lining 14 also participating in the protection and ballasting of the structure. In particular in order to retain this lining, the external wall 3 stops at a level higher than that of the fallout from the dome 13.

If the products stored are at normal temperature, there is no disadvantage in securing the dome 1 and the external wall 3 with the slab 6 and the internal wall 9 but, when relatively large temperature differences are to be expected between the temperature ambient and that of the interior of the container, the cupola 1 and the external wall 3 are separated from the tank.

For this purpose, it is possible to interpose, between the pillars 5 and the slab 6, supports 15, similar to those of the bridges and which allow relative movements of the parts while ensuring the transmission of significant vertical forces. Such supports can be produced by means of hooped elastomers, such as neoprene.

In order to avoid overall displacement of the inner tank, in particular in the event of an earthquake, all around the belt 2 are distributed keys 16 (FIGS. 1 and 2) formed of radial slots or mortises 17 with rectangular profile in which are engaged tenons 18 provided under the slab 3.

Elastic supports 19, similar to the supports 15, are interposed horizontally and vertically between the tenons 18 and the mortises or slots 17.

Naturally, the internal tank can be provided with any suitable coating. For example, if gas exchanges between the outside and the inside of the tank are to be avoided (entry of air or water vapor, exit of dangerous gases), the slab 6, the wall 9 and the dome 13 can be coated with waterproofing paint or plated thin sheet metal.

Figure 4 shows the principle of a device. ventilation or ventilation system with which the container may be fitted.

The air coming from the outside atmosphere is introduced by conduits 21 in the gallery 10 before passing into space 7 by the slots reserved between the keys 16. It is then returned to the atmosphere by conduits 23 on which fans and any desired detection devices can be arranged. An access gallery for surveillance personnel is advantageously provided along the conduits 23. These conduits pass through the dome 1 by watertight passages 24. Outside the container, they are protected by concrete sheaths 25.

• - exécution de la paroi moulée à partir du sol naturel ou d'un terrassement prélable;
• - terrassement à l'intérieur de la paroi 26 avec exécution, en descendant, d'anneaux de raidissement 27;
• - exécution de la coupole 1 à l'abri d'un rabattement de la nappe phréatique.

In the variant of FIG. 5, the lower part 26 of the external wall 3 has been produced by the technique of molding in the ground. We can operate as follows:

• - execution of the diaphragm wall from the ground natural or of a preliminary earthwork;
• - earthwork inside the wall 26 with execution, descending, of stiffening rings 27;
• - execution of the dome 1 protected from a drawdown of the water table.

Other techniques can be used, for example the execution of part 26 by means of sheet piles subsequently coated with concrete.

If the container is intended to be stranded, it is possible, as shown in FIG. 6, to provide a slab 28 under the dome 1. This slab 28 is linked to the dome 1 by posts 29. It allows stranding on a seat underwater.

As illustrated in Figure 7, one can also provide a deck 30 mounted on the dome 13 by means of posts 31 and allowing the establishment of various installations.

It goes without saying that the embodiments described are only examples and that it would be possible to modify them, in particular by substituting technical equivalents for some of the means listed in the claims.

Claims (8)

1. High-safety container intended more specially for dangerous products or installations, comprising a tank (6, 9) which rests, through supports permitting expansion, on a continuous leak-tight foundation (1), leaving a ventilating gap (7) beneath said tank (6, 9), said foundation (1) being extended in an outer wall (3), an external wall (3) bounding an annular space (10) around the tank (6, 9, 13), characterized in that said annular space (10) is provided with a filler (12) contributing to ensure the stability of the container in respect of a lifting by hydrostatic thrust even when the container is empty, and to protect the container against external shocks or projectile shooting, and that the lower edge of the tank (6, 9) rests on the foundation (1) through keys (16) preventing bodily motions of the tank (6, 9) relative to the foundation (1) while permitting expansion of the tank (6, 9).

2. Container according to claim 1, characterized in that the keys (16) are formed by mortises (17) and tenons (18) engaging into said mortises (17), elastic supports (19) being interposed between the tenons (18) and the mortises (17).

3. Container according to any one of claims 1 and 2, characterized in that the foundation is formed by a cupola (1) having its concave side facing upwardly and upon which the tank (6, 9) rests through pillars (5).

4. Container according to any one of claims 1 to 3, characterized by ventilation ducts connecting the spaces provided between the tank (6, 9), the foundation (1) and the external wall (3) to the atmosphere.

'5. Container according to any one of the preceding claims, characterized in that the tank (6, 9) is provided with a dome (13) that can be covered with a lining (14) also contributing to the protection and ballasting of the container.

6. Container according to claim 5, characterized in that the dome (13) is surmounted by a plate structure (30) permitting installation of a variety of gears.

7. Container according to any one of claims 1 to 6, characterized in that a supporting slab (28) is provided specially in order to permit stranding of the container on a seating provided under water.

8. Container according to any one of claims 1 to 7, characterized in that the lower part (26) of the external wall (3) is constructed by moulding into the soil.

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