WO1988007013A1 - Improved device for preventing the explosion of vessels containing hydrocarbons - Google Patents

Abstract

Improved device for preventing the explosion of vessels containing liquid or gaseous hydrocarbons. The interior of the vessel is wholly or partially provided with elements, small in size in relation to the dimensions of the vessel, consisting of thin, punched metal sheets (1) folded or rolled onto themselves to form elements substantially spherical or parallelepipedal in shape.

Description

 Improved device to avoid the explosion of tanks containing hydrocarbons.

The present invention relates to an improved device for preventing the explosion of tanks containing liquid or gaseous hydrocarbons.

It has already been imagined to place inside the tanks intended to contain flammable liquids metallic materials such as knitted threads which occupy the interior of the tank leaving an interstitial volume almost as large as the capacity of the tank.

Such devices have not been able to be really exploited to date, on the one hand due to the fact that the filling of such tanks has proved difficult and costly, and on the other hand to the fact that during the use of the tank there was a significant compaction of the packing material which no longer occupied the entire internal volume of the container and therefore lost much of its effectiveness.

The present invention relates to an improved device which makes it possible to eliminate these drawbacks while being simple and economical to produce.

The present invention relates to an improved device for preventing the explosion of tanks containing liquid or gaseous hydrocarbons, which is characterized by the fact that the interior of the tank is at least partially lined with elements of relatively small dimensions compared to the size of the reservoir αui consist of perforated metal sheets of very small thickness, folded or wound on themselves to form elements of substantially parallelepipedic and / or spherical shape.

According to the invention, the elements of parallelepiped shape are preferably intended for large tanks such as for example storage tanks, while the spherical elements are more particularly intended for small tanks such as for example motor vehicle tanks.

However, in accordance with the invention, it is possible to fill the majority of the volume of a reservoir with the aid of parallelepiped elements, and to fill the remaining volume parts with the aid of spherical elements. According to a preferred embodiment of the invention, these elements are made from thin metal sheets, good conductors of heat, such as for example sheets aluminum or copper, in which numerous perforations are made, for example by the known technique for obtaining the expanded metal, these sheets preferably comprising certain strips devoid of orifices constituting ribs of small dimensions which make it possible to stiffen the sheet and consequently the elements which are produced using the latter.

Such ribs avoid that during the use of the container according to the invention, the elements do not undergo any compaction which would leave a significant part of the tank unoccupied.

According to a preferred embodiment, the parallelepipedic elements can be formed by winding a metal sheet on itself parallel to the ribs which it may comprise.

This winding can be carried out so as to directly give a square section which thus makes it possible to obtain the parallelepiped element. The winding can also be carried out in the form of a cylindrical roller which is then formed into a rectangular shape by lateral compressions.

According to a preferred embodiment of the invention, the internal volume of a large capacity tank is filled with cubic elements which are arranged so that an alignment of the winding axes of the metallic sheets of different elements in the directions which undergo the main forces which can lead to the packing of the interior lining of the tank.

Thus in a tank which is intended to undergo accelerations in various directions, the interior lining of the tank is made up of elements whose winding axes are aligned in the three directions of the edges of the cubes, the remaining cubic elements being able to be arranged in any directions.

In the case of a static tank, the cubic elements can all be arranged with their vertical winding direction.

When dealing with a large tank using elements of parallelepiped shape, these are put into place in the tank before the tank is completely closed, the volume remaining between the walls of the tank and the parallelepipeds being able to be filled with spherical elements according to the invention.

In the case of a small tank, such as for example the tanks of motor vehicles, use is preferably made of the spherical elements according to the invention, which are directly introduced through the filling opening of the reservoir and thus spontaneously lining the interior of the latter.

In order to better understand the invention, we will now describe by way of illustration and without any limiting character several embodiments taken as examples and shown in the accompanying drawing.

On this drawing :

FIG. 1 is a schematic perspective view of an expanded metal element which can be used to produce elements according to the invention,

FIGS. 2 to 5 schematically represent how a sheet of expanded or perforated metal can be transformed to produce a spherical element in accordance with the invention,

- F igure 6 shows a schematic sectional view of a hydrocarbon tank lined with spherical elements according to the invention.

- Figures 7 to 9 show how a parallelepiped element can be used which can be used in accordance with the invention, and Figure 10 schematically represents a preferred embodiment of the arrangement of cubic elements according to the invention.

Schematically shown in Figure 1 how a thin metal sheet, good conductor of heat and not likely to be corroded by hydrocarbons, such as, for example, a sheet of aluminum or copper, can be provided with openings on the majority of its flat surface, for example thanks to the known technique used to produce what is known as expanded metal.

In accordance with a preferred embodiment of the invention, certain parts 2 of the sheet 1 are left without openings and are shaped by folding to produce a rib which, although of small size, allows significant stiffening of the sheet 1 which, on the one hand, taking into account its very small thickness, and on the other hand, taking into account the numerous orifices A which it comprises (and of which only those which are in the vicinity of part 2 are shown in the drawing) that a low own rigidity.

It will be understood that when an element according to the invention is produced from a sheet as shown in FIG. 1, the ribs 3 give it significant rigidity parallel to the direction of these ribs, and that even when this element has been deformed to be put for example in the form of a sphere, the ribs 3, although deformed, nevertheless maintain the shape of the sphere by supporting the perforated parts of the sheet 1.

According to the invention, the ribs 3 can be produced at determined spacings of the sheet which are a function of the use which it is desired to make of it and in particular the size of the elements produced in accordance with the invention.

The purpose of the surfaces 2 not provided with orifices 4 is essentially to allow good fixing of the perforated parts 4 to the rib 3, mainly when the sheet 1 is deformed other than by folding along lines parallel to the rib 3.

Figures 2 to 5 show how it is possible to make a spherical element 5 according to the invention from a sheet 1 shown in Figure 2, which can be the sheet of Figure 1, but which can also be a sheet simply perforated or deployed, that is to say not comprising the ribs 3, although these ribs constitute a preferred embodiment of the invention.

As shown in FIG. 2, the sheet 1 is folded over its lateral parts 1a and 1b to form a strip 6 which has three thicknesses of sheet 1 and which is shown in perspective in FIG. 3.

These bands 6 are then cut into elements 7 of substantially square shape which are then deformed to be put into the form of substantially spherical pellets which have been represented in FIG. 5.

According to the invention, the spherical elements 5 can have a diameter, for example of about a half to a few centimeters.

It is also not necessary that these elements all have the same diameter, or even that they have a perfectly spherical shape, the advantage of this type of elements being to be able to garnish the interior of a container by simple flow of the spherical elements in the container, as shown in FIG. 6 where we can see how substantially spherical elements 6 which are not all of the same size fill almost the entire internal volume of a container 8.

There is shown in Figures 7 to 9 the embodiment of an element according to the invention of parallelepiped shape.

In this embodiment, there is wound, as shown in Figure 7, a sheet 1 such as for example that of Figure 1 parallel to the ribs 3 which, in this way, are not deformed.

The roller 9 thus obtained is then placed between the plates 10 of two presses which give it a square section.

It will be understood under these conditions that if the sheet 1 has been cut into strips whose width corresponds to the spacing of the jaws of the press shown in FIG. 8, elements of cubic shape are obtained as shown in FIG. 9 or else a parallelepipedic element if the sheet 1 has been cut into strips of different dimensions.

It goes without saying that the parallelepipedic or cubic elements according to the invention can also be produced with sheets 1 which do not have ribs 3, the rigidity of the expanded metal being nevertheless greater in the direction perpendicular to the deployment than in the direction of the deployment well said.

It follows that, even if the parallelepipedic elements 11 are produced using a sheet without ribs 3, (although these ribs 3 are considered preferable according to the invention), the resistance to deformation of the element 11 is larger in the direction parallel to the winding axis of the roller 9 than in the perpendicular directions.

FIG. 10 shows a preferred mode of arrangement of cubic elements 11 according to the invention which are arranged inside a tank which is generally of large capacity.

In schematic figure 10 we see how the cubic elements 11a are superimposed along their winding axes to produce vertical columns aligned in the direction of greatest resistance of the cubic elements.

This gives the packing a significant resistance to crushing in the vertical direction.

We also see in Figure 10 how the elements 11b are arranged with their winding axes aligned to make parallel columns going from front to back of Figure 10, which gives the packing a significant resistance to crushing in that direction.

Finally, it can be seen in FIG. 10 how the elements 11c are aligned in the winding direction of their axes to form columns which go from left to right to give the lining a notable resistance to crushing in this direction. We understand that in this way we made stacks of cubic elements in the direction of their greatest resistance, said stacks being made along three axes of the lining of the tank, which prevents successive filling and emptying as well as vibrations to which the tank is subjected do not lead to a compaction of the elements according to the invention.

The cubic elements which are arranged between the stacks along the three axes can be directed in any way.

According to the invention, when we are dealing with a static tank whose lining undergoes only vertical compression forces, it is possible to arrange all of the elements with their vertical winding axes.

It is understood that the embodiments of the invention which have been described above are in no way limiting and that they can receive any desirable modification without departing from the scope of the invention.

In particular, it is clear that the orifices which are formed in the thin metal sheets can be produced by a technique different from that used to manufacture the expanded metal.

It also goes without saying that other techniques can be used to produce the parallelepipedic or cylindrical elements.

Finally, it is understood that when this is necessary, for example for very large tanks or for tanks subjected to very intense vibrations, it is possible to integrate support structures into the lining which avoid the settlement which could occur. in extreme conditions.

Claims

CLAIMS 1. Improved device for preventing the explosion of tanks containing liquid or gaseous hydrocarbons, characterized in that the interior of the tank is lined at least partially by elements (5,11) of relatively small dimensions compared to the size of the tank which consist of perforated metal sheets (1), of small thickness, folded or wound on themselves to form elements of substantially parallelepiped shape (11), and / or spherical (5) 2. Device according to claim 1, characterized in that the elements (5,11) are made from metal sheets (1) of small thickness, good conductors of heat, such as for example aluminum sheets or of copper, in which numerous perforations are made (4). 3. Device according to any one of claims 1 to 3 characterized in that the sheets (1) have strips without orifices which are provided with ribs (3) of small dimensions which allow to stiffen the sheet (1) and as well as the elements (5,11) produced using the latter. 4. Device according to any one of claims 1 to 3, characterized in that a parallelepipedic element (11) is produced by the winding of a sheet (1). 5. Device according to claim 4, characterized in that the parallelepipedic element (11) is produced by winding a sheet (1) in the form of a cylindrical roller (9) which is then formed into a rectangular shape by lateral compressions. 6. Device according to any one of claims 1 to 5 characterized in that the tank is furnished with elements (11) which are arranged so that one obtains stacks of elements with winding axes aligned in the directions which undergo the main forces which can lead to the packing of the interior lining of the tank. 7. Device according to claim 6, characterized in that the interior lining of the tank comprises stacks of elements (11a, 11b, 11c) whose winding axes are aligned in the three directions of the edges of a cube. 8. Device according to claim 6, characterized in that the parallelepipedic elements (11) are all arranged with their vertical winding direction. 9. Device according to any one of the preceding claims, characterized in that the lining is constituted by a stack of parallelepipedal elements (11), the space remaining inside the tank being filled with elements of spherical shape. (5). 10. Tank for hydrocarbons, characterized in that it comprises a device according to at least any one of the preceding claims.