EP2938562B1 - Device for prevention of liquid overflow from an outside liquid storage installation, storage installation, use, method - Google Patents

Description

The invention relates to a device for preventing overflow outside an open-air storage installation of this liquid, and in particular a fuel storage installation, an installation, a use and a method. A liquid storage installation conventionally comprises one or more tanks or tank (s), for example tanks for storing combustible product, and a means for retaining this liquid around the tank (s), for example a wall or a merlon forming a retention basin.

Such a barrier means is designed with dimensions to contain the entire volume of liquid in the tray. Thus, if the liquid flows slowly enough from the storage tank, the liquid remains confined in the installation.

However, in the event of a sudden rupture, following a cracking of the tank, for example, there is a risk that the liquid may spill in part outside the installation. Indeed, if the tank has a gap such that the liquid flows with a certain kinetic energy, a portion of the liquid may overflow the retention means, which causes pollution of the environment.

Such a sudden rupture can in particular be caused by the corrosion of the tank, which can be significant when the liquid is crude oil, and / or by the variations of the mechanical stresses applied to the periphery of the tank in contact with the bottom according to the filling level of the tank. The documents DE102005053911A1 and DE102004002217A1 disclose overflow prevention devices. There is a need for better protection of the environment.

It has been envisaged to have an obstacle occulting between the tank and the wall, of the second wall type, but in the event of rupture of the tank, the liquid pouring against this second wall may form a wave because of the impact against it. wall, because of the dynamic pressure exerted on the wall. The amount of liquid able to pass the retention means may be relatively high.

It has also been envisaged to add a confinement outside the retention basin, but this addition can be difficult to carry out on existing facilities. In addition, in case of a pool fire, in the case of hydrocarbons, the fire may be difficult to control.

Finally, it has been envisaged, in the case of oil storage bins, to make more frequent the operations of opening the bins to remove sediment, to better control the corrosion of bins and limit the risk of sudden rupture. This nonetheless implies increased maintenance. The invention is solved with a device according to claim 1. It is proposed a liquid overflow prevention device outside an open air installation comprising a storage tank of the liquid and a liquid retention means arranged around this tray, comprising a plate element intended to be arranged between the tray and the retention means, this plate element defining an impact surface of the liquid pouring against this plate in case of rupture of the tray and the openings distributed over this surface and through this plate element to reduce the kinetic energy of this liquid.

Thus rather than a blackout obstacle that may cause the liquid to form a wave, it installs a plate element for example pierced holes. At least a portion of the liquid pouring against this plate passes through the orifices of the plate. The velocity vectors of the elementary volumes of the liquid can then have various directions, which can cause a rapid decrease in the kinetic energy of the entire liquid after the impact. Thus, the liquid undergoes a loss of pressure following the impact against the perforated plate, so that if the retention means is then reached, the risk of overflow is lower than in the prior art.

Advantageously and in a nonlimiting manner, the porosity associated with the openings of the plate element can vary between 10% and 40%, inclusive.

Advantageously and in a nonlimiting manner, the openings may have a passage section varying between 0.001 and 0.01 m ² , advantageously between 0.002 and 0.006 m ² , inclusive.

Advantageously and in a nonlimiting manner, the number of openings per m ² of impact surface may vary between 10 and 200, advantageously between 20 and 150 inclusive.

The plate element, also called plate by abuse of language in the present application, can define a plane impact surface, or not. By For example, it will be possible to provide a plate element defining a relatively curved impact surface, for example with a radius of curvature close to that which would have a circle on which several plate elements surrounding the tray are arranged.

In the present description, reference will be made to the plane of the plate element to designate either the plane of a plane impact surface, a tangent plane or a mean plane of this impact surface.

The openings may have a homogeneous distribution, or not. According to the invention, these are orifices with a closed contour, for example circular, oblong, square or other orifices, defined in the plate, or rectilinear openings, the plate element comprising a set of inclined blades, in the manner of a blind, so as to form an opening between each doublet of two adjacent blades. Advantageously, the longitudinal edges of the blades can be horizontal, and the inclination of the blades such as the openings define passages bringing the liquid to the ground.

The orifices may form a conduit in the thickness of the plate, and / or beyond the plate. For example, it is possible to weld tubes opening to a surface of the plate opposite to the impact surface at the locations corresponding to the orifices of the plate.

Advantageously, however, will be chosen simpler forms, such as perforated sheet metal or expanded sheet.

Advantageously and in a nonlimiting manner, the device may further comprise a support means of the plate element, to keep the plate element erected relative to the ground.

"Ground plane" means the plane tangent to the ground where the plate is erected.

The invention is not limited by the shape of the support means: it may for example be a frame intended to be placed on the ground, and defining a groove in which a flange of the plate can be inserted, Or other.

The dimensions of the plate element and the impact surface are chosen to allow a significant reduction in the kinetic energy of the fluid flowing on this plate element in case of rupture of the tray.

Advantageously and in a nonlimiting manner, the plate element and / or the impact surface may have a height greater than or equal to 50 centimeters, advantageously greater than or equal to 1 meter, advantageously between 1 and 4 meters, these terminals being included.

Advantageously and in a nonlimiting manner, the plate element and / or the impact surface may have a width greater than or equal to 50 centimeters, advantageously greater than or equal to 1 meter, advantageously between 1 and 6 meters, these terminals being included.

The dimensions of the impact surface can be chosen according to the dimensions of the possible gaps whose effects one wishes to control.

For example, one can design plate elements each able to capture and thus reduce the energy associated with a gap of dimensions 2 meters x 2 meters on the first shell of a tank. Each plate element may thus have a height greater than or equal to 2 meters and a width greater than or equal to 2 meters, it being understood that this plate element is intended to be positioned with its normal vector substantially in the direction of the possible flow. When it is desired to limit the pollution caused by a larger gap, for example 3 meters high and 90 meters wide (ie an angular gap of about 120 ° of a tank shell with a diameter of 86 meters), we can choose to place several plate elements contiguously around the tray.

Advantageously and in a nonlimiting manner, the device may be arranged so that at least one (and preferably all) opening (s) define (s) a passage for the circulation of liquid in a direction forming an angle with the horizontal, advantageously an angle greater than 10 °, for example close to 15 °. Liquid passing through the plate can be redirected to the ground, which can further limit the formation of a wave.

Advantageously and in a nonlimiting manner, the support means may be arranged so that the erected plate is inclined relative to the vertical (here the normal direction to the ground plane), preferably an angle greater than 10 °, for example close to 15 °. Thus, the plate can be arranged so that the plate forms with the ground an acute angle for the liquid flowing from the storage bin, rather than a springboard. Such an arrangement can make it possible to limit the formation of a wave and to bring the liquid to the ground.

Advantageously and in a nonlimiting manner, the device can be arranged so that at least one (and preferably all) opening (s) define (s) a passage for the circulation of liquid in a direction forming a non-zero angle with a direction a vector normal to the plane of the plate, for example greater than 20 °, for example close to 30 °. Thus, even by arranging the plate so that its plane forms an angle of nearly 15 ° with the vertical, the orifices can allow to drive the liquid to the ground, at an angle of almost 15 ° with the horizontal.

Advantageously and without limitation, the device may be arranged so that the impact surface and / or the openings of the plate are oriented (s) so as to bring the liquid to the ground.

Advantageously and in a nonlimiting manner, the support means may be arranged so that the erected plate is inclined relative to the normal to the ground plane when installed on the ground, so as to form a first angle with this normal, and at least one plate member may be arranged such that at least one (and preferably all) opening (s) define (s) a passage for liquid flow in a direction forming a second angle with a direction of a normal vector to the plane of the plate, this second angle having a value greater than that of the first angle and an orientation such that the liquid arriving on the side of the plate element such as the plate element and the ground form an acute angle for this liquid to be returned to the ground during the passage through said at least one opening.

Advantageously and in a nonlimiting manner, the device may comprise a plurality of plate elements, for example two, three or four plate elements, arranged so as to form a superposition of plate elements. Thus, the liquid passing through the orifices of a first plate member encounters a second plate member also defining orifices. This superposition of perforated plates can thus participate in the pressure drop of the liquid flowing from the damaged container.

Advantageously and in a nonlimiting manner, the device can be arranged so that for at least two plate elements, the liquid flow directions through these plate elements are different. For example, an angle difference greater than 10 ° may be provided, for example of the order of 15 ° or 30 °. Thus, at least one (and preferably all) orifice (s) of one of the plate elements define (define) a passage for the circulation of liquid in a direction different from that of the passage defined by at least one (and advantageously all the orifice (s) of another plate element. These two plate elements may be adjacent in the superposition of plate elements of the device, or not.

Advantageously and in a nonlimiting manner, the device may comprise a perforated plate and an expanded sheet metal, the perforated sheet being disposed upstream of the expanded sheet with respect to the direction of flow of the liquid from the tank, or alternatively downstream.

Advantageously and without limitation, the device may comprise a first plate element, a second plate element and a third plate element. The first and third plate members may be similar and be disposed on either side of the second plate member.

The first and third plate members may each include an expanded sheet.

The second plate member may comprise a perforated plate.

Advantageously and in a nonlimiting manner, the void percentage of the perforated sheet varies between 10% and 40%, these limits being included. The perforations may be round, oblong, or other.

The thickness of the perforated plate can vary between 0.4 mm and 10 mm.

The thickness of the sheet used to make the expanded sheet can vary between 0.4 mm and 10 mm.

When the sheet is relatively thin, for example, for a thickness less than or equal to one millimeter, the device can be designed for a single use. In the event of a bin rupture, the overflow prevention device is then replaced.

For the expanded sheet, it is possible to provide a strap width varying between 1 and 20 mm, for example between 5 and 10 mm, a mesh length between 3 and 200 mm, advantageously between 5 and 70 mm, a mesh width between 2 and 5 mm. and 100 mm, advantageously between 3 and 30 mm, a liner thickness advantageously between 1 and 5 mm, and a total thickness of the expanded metal between 0.5 and 50 mm, advantageously between 1 and 8 mm. The ducts thus formed allow to deflect a portion of the liquid meeting the sheet.

It will be possible to choose an expanded sheet with an equivalent percentage of vacuum, taken at a plane at half the thickness of the sheet, between 10% and 40%, advantageously close to 25%.

The sheets can be made of steel, in particular stainless steel, aluminum, brass, copper or other.

The expanded sheets can be made by shearing and unfolding a sheet made of a malleable metal or alloy, or alternatively by molding a metal or alloy with little or no malleability, for example gray cast iron or zamak. In general, the invention is in no way limited by the method of obtaining the plate elements.

Advantageously and in a nonlimiting manner, the support means may be arranged to define a space between at least one (and preferably each) plate element and the ground, for the circulation of liquid. Thus, leaving for example between 5 and 20 cm, for example almost 10 cm between the ground and the plates, liquid can circulate under the plates, which reduces the amount of liquid likely to form a wave. This space can also limit the stagnation of liquid retained by the plates, and thus reduce the risk of accumulation of gas at ground level, and therefore the risk of an explosion related to such a gas sheet.

A plurality of devices as described above may be arranged around one or more storage bins, so as to leave passages for the circulation of operators, for example staggered.

It is furthermore proposed an external installation according to claim 12 comprising a liquid storage tank, a liquid retention means disposed around this tank and at least one device as described above, arranged between the tank and the means retention.

The liquid can be a crude oil, be derived from refining, or other. Although the invention finds a particularly interesting application in the oil industry, because of the risk of pollution associated with the stored products, it is in no way limited to liquids from the crude oil. It could well be implemented in other industries, including the storage of liquid fertilizers, and more generally any liquid likely to cause damage to the environment.

It is further proposed a use of the device according to claim 13 as described above in an installation in the open air storage of liquid from oil, for example crude or refined oil, fuels, compounds petrochemical, or other.

In addition, an overflow prevention method according to claim 14 is provided outside an outdoor installation comprising a storage tank for this liquid and a liquid retention means disposed around this tank, comprising a step of depositing a plate element between the tank and the retention means, this plate element defining an impact surface of the liquid pouring against this plate in case of rupture of the tray and the openings distributed over this surface and through this element plate to decrease the kinetic energy of this liquid.

Advantageously and without limitation, provision may be made to arrange a plurality of these devices around the tray, for example so that for this device, an impact surface is oriented substantially towards one or more tray (s). It can advantageously be provided to distribute these devices relatively evenly around the tray (s), so as to leave passages for the evacuation of people.

Advantageously and in a non-limiting manner, the prevention devices may be arranged between the first quarter and the last quarter of the distance between the storage bins and the retention means, for example halfway between the bins and the retention wall. .

Advantageously and in a nonlimiting manner, the prevention devices can be arranged with an orientation such that the impact surfaces of the plates are turned towards the storage bins. The devices can thus be arranged substantially parallel to an outer surface of the tray.

• La figure 1 est une vue d'en haut et très schématisée d'un exemple d'installation, selon un mode de réalisation de l'invention.
• La figure 2 est une vue en coupe d'une partie d'un exemple d'installation, selon un mode de réalisation de l'invention.

The invention will be better understood with reference to the figures, which illustrate non-limiting embodiments.

• The figure 1 is a top view and very schematic of an example installation, according to one embodiment of the invention.
• The figure 2 is a sectional view of a portion of an example installation, according to one embodiment of the invention.

Identical references can be used from one figure to another to designate identical or similar elements.

With reference to the figure 1 , an installation 1 in the open air storage crude oil has tanks 10 placed outside, here storage tanks for crude oil. Each tank 10 can store for example 15000 m ³ of oil.

We can even provide larger bins still. For example, a storage tank may be between 3 and 30 meters high, for example about 20 or 25 meters high, and 1 to 100 meters in diameter, for example between 40 and 50 meters in diameter.

In the event of a sudden rupture, for example with the creation of a 70 cm gap, this volume of oil is discharged with a relatively high potential energy into the installation.

A merlon 12 surrounds the tanks 10, so as to form a retention basin. The height of the merlon can be between 1 and 3 meters. The merlons may for example be located at a distance from the bins 10 between 10 meters and 50 meters.

Alternatively, we could provide a wall in place of the merlon.

This retention bowl is dimensioned to retain the volume stored in each of the tanks 10. Nevertheless, if the oil is dumped with a relatively high kinetic energy, there is a risk of overflow or overflow.

Oil overflow prevention devices 11 are arranged in staggered rows around the tanks 10. These devices make it possible, by their structure and their disposition, to reduce the kinetic energy of the oil potentially discharged from a tank 10, in the event of a sudden rupture and This staggered arrangement can furthermore allow the operators to circulate easily in the installation, and if necessary to quickly evacuate the installation. Finally, in the event of fire, this arrangement of the devices 11 allows the spreading of the extinguishing foam.

Each device comprises at least one plate element defining an impact surface for the liquid capable of pouring against this plate, and defining openings distributed over this surface, and through this plate element.

• de porosité P, la porosité P étant obtenue en divisant la section de passage de l'ensemble des trous d'une surface d'impact par la superficie de cette surface,
• de nombre N de trous par m² de l'élément de plaque,
• de diamètre de trous D, et
• de section de passage S par trou.

Tableau 1 P en % N D en cm S en m² 10 20 8 0,005024 20 40 8 0,005024 25 50 8 0,005024 30 60 8 0,005024 40 80 8 0,005024 10 35 6 0,002826 20 71 6 0,002826 25 88 6 0,002826 30 106 6 0,002826 40 142 6 0,002826 Table 1 below gives examples of values:

• porosity P, the porosity P being obtained by dividing the passage section of all the holes of an impact surface by the area of this surface,
• number N of holes per m ² of the plate element,
• diameter of holes D, and
• of passage section S per hole.

Table 1 P in% NOT D in cm S in m ² 10 20 8 0.005024 20 40 8 0.005024 25 50 8 0.005024 30 60 8 0.005024 40 80 8 0.005024 10 35 6 0.002826 20 71 6 0.002826 25 88 6 0.002826 30 106 6 0.002826 40 142 6 0.002826

With reference to the figure 2 an overflow prevention device 11 may comprise three superposed plate elements 111, 112, 113.

This figure 2 is not to scale.

Each plate element defines an impact surface 131, 132, 133 against which comes some of the oil from the tank 10 in the event of a sudden rupture of this tank 10, as well as a rear surface 141, 142, 143 opposite to the impact surface.

In addition, each plate member 111, 112, 113 defines orifices (not shown in the figure 2 ), distributed over the impact surface and passing through the plate member. Each orifice thus defines a conduit through the corresponding plate member for the passage of oil.

• d'une part maintenir les plaques 111, 112, 113 relativement éloignées du sol, de façon à créer un espace 114 pour la circulation du pétrole en cours d'évacuation ; et
• d'autre part, maintenir les plaques dressées avec une inclinaison par rapport au sol.

The plate elements, or plates 111, 112, 113 are mounted on a support means 110. This support means is arranged for:

• on the one hand keep the plates 111, 112, 113 relatively far from the ground, so as to create a space 114 for the circulation of oil during evacuation; and
• on the other hand, keep the plates erect with an inclination to the ground.

The oil coming from the tank 10, which arrives with a speed having a substantially horizontal direction, according to the arrow 20, thus goes for a part to pass under the plates 111, 112, 113, by the space 114, and for another part to hit the impact surface 131. The inclination of the impact surface makes it possible to contribute to bringing the oil to the ground.

For example, it is possible to choose an inclination such that the angle α between the plane of the plates and the vertical direction, here represented by the line (D) is between 12 ° and 18 °, advantageously of the order of 15 °.

Furthermore, the orifices of the different plates define liquid circulation conduits in non-horizontal directions, and different from one plate to the adjacent plate.

Thus, the first plate 111 is a expanded metal grid for which the inclination of the strips (according to the arrows 21) varies between 12 ° and 18 °, and is preferably close to 15 ° relative to the horizontal when the plate 111 is itself inclined nearly 15 ° from the vertical. In other words, the plate 111 is shaped to form ducts inclined by nearly 30 ° with respect to a vector normal to the plane of the plate.

The second plate 112 is a perforated plate, defining ducts in the thickness of the plate and corresponding to a direction parallel to the vector normal to the plane of this plate 112. In other words, after having been brought down, in a direction forming an angle of 15 ° with the horizontal, the liquid passing through the orifices of the plate 112 follows a path with this time an inclination of 15 ° relative to the horizontal, but upwards (according to the arrow 22). It is conceivable that these movement direction variations cause relatively large losses of loads.

The porosity of this second plate 112 is 40%.

Finally, the third plate 113 is identical to the first plate, and arranged with the same inclination. The movement of the passing liquid through the mesh of this plate 113 is effected along the arrow 23, that is to say again towards the ground, which further reduces the energy of the liquid.

The plates 111, 112, 113 may for example have dimensions of the order of one meter, for example between 1 and 4 meters for the height and between 1 and 6 meters for the width, for example 2 meters high and 3 meters. width. In the example of the figure 2 the elements 111, 112, 113 have different heights, but one could choose plate elements of the same dimensions.

The space 114 may have a height of 10 or 15 cm for example. The device 11 is open at the bottom, it limits the accumulation of gas between the device 11 and the tank 10, and therefore the risk of explosion.

For fixing the plates 111, 112, 113, it will be possible for example to provide frames and screw systems, or other.

Tests, carried out on a scale of 1 / 10th, showed that this device made it possible to avoid the formation of waves for a tank having an equivalent height of 20m and torn from a gap having an equivalent length of 70 cm. For these tests, a PVC tube 20 cm in diameter and height of 2 meters was used, with a gap of 7 cm at the bottom of the PVC pipe, a model of the prevention device 15 cm high and 20 cm wide. , placed at 40 cm from the PVC tube. The model of the retention means also has a height close to 15 cm and is placed at 50 cm from the PVC tube. The PVC tube is initially filled with water at 20 ° C.

If the first grid 111 is removed and the second plate 112 is replaced by a sheet similar to the fact that the porosity is reduced to 10%, the results remain better than in the absence of a prevention device. overflow.

If we reintroduce the first grid 111 and maintain the second sheet (with a porosity of 10%), the result remains very satisfactory, in that there is almost no overflow beyond of the retention wall.

The tests also showed that if the retention means was a merlon forming a slope of 45 °, it was wise to use a second sheet 112 with a porosity of 10%, while for a wall, a porosity of 40% was more appropriate.

In the present application, the terms "high", "low", "horizontal", "vertical", etc., were used for use of the prevention device on a so-called horizontal ground, the gravity vector then being vertical and oriented from top to bottom. Nevertheless, it will be understood that the orientation of this device may be different, especially during storage, transport, etc.

Claims (14)

1. A device (11) for preventing liquid overflow out of an outdoor installation comprising a storage tank (10) for said liquid and a liquid retention means (12) disposed around said tank, comprising a plate element (111, 112, 113) intended to be disposed between the tank and the retention means, said plate element defining an impact surface (131, 132, 133) for liquid spilling onto this plate in the event of the tank rupturing, characterized in that the plate element defines openings distributed over said surface and through said plate element in order to reduce the kinetic energy of the liquid, said openings being chosen among :

   orifices having a closed contour that are defined in the plate,

   rectilinear openings, the plate element comprising a set of inclined slats, in the manner of a blind, so as to form an opening between each pair of two adjacent slats.
2. The device (11) as claimed in claim 1, also comprising a support means (110) for the plate element, in order to keep the plate element (111, 112, 113) standing with respect to the ground.
3. The device (11) as claimed in claim 1, wherein the support means (110) can be arranged so as to define a space between the plate element (111, 112, 113) and the ground, for the flow of liquid.
4. The device (11) as claimed in either of claims 2 and 3, wherein the support means (110) is arranged such that the standing plate element is inclined with respect to a direction normal to the plane of the ground.
5. The device (11) as claimed in one of claims 1 to 4, wherein the device is arranged such that at least one opening defines a passage for the flow of liquid in a direction (21, 23) that forms a non-zero angle with a direction of a vector (22) normal to the plane of the impact surface.
6. The device (11) as claimed in one of claims 1 to 5, comprising a plurality of plate elements (111, 112, 113) disposed so as to form a superposition of plate elements.
7. The device as claimed in claim 6, wherein the device is arranged such that for at least two plate elements (111, 112; 112, 113), the directions (21, 22; 22, 23) of liquid flow through said plate elements are different.
8. The device as claimed in either of claims 6 and 7, wherein the plurality of plate elements comprises two expanded sheets (111, 113) and a perforated sheet (112) placed between said expanded sheets.
9. The device as claimed in any one of claims 1 to 8, wherein the impact surface (131, 132, 133) has a height that varies between 1 and 4 meters.
10. The device as claimed in any one of claims 1 to 9, wherein the porosity associated with the openings varies between 10% and 40%.
11. The device as claimed in any one of claims 1 to 10, wherein the number of openings defined by the plate element varies between 10 and 200 per square meter of impact surface.
12. An outside installation (1) comprising a liquid storage tank (10), a liquid retention means (12) disposed around said tank and at least one prevention device (11) as claimed in one of claims 1 to 11 disposed between the tank and the retention means.
13. The use of at least one device as claimed in one of claims 1 to 11 in an outdoor installation for storing liquid obtained from oil.
14. A method for preventing liquid overflow out of an outdoor installation comprising a tank for storing said liquid and a liquid retention means disposed around said tank, comprising
    disposing a plate element between the tank and the retention means, said plate element defining an impact surface for the liquid spilling onto this plate in the event of the tank rupturing,
    characterized in that said plate element defines openings distributed over this surface and through said plate element in order to reduce the kinetic energy of this liquid, said openings being chosen among :

    orifices having a closed contour that are defined in the plate,

    rectilinear openings, the plate element comprising a set of inclined slats, in the manner of a blind, so as to form an opening between each pair of two adjacent slats.

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