WO2018166842A1

WO2018166842A1 - Anchoring structure formed from a single panel cut for an anti-erosion covering, in particular for protecting a wall of a catalytic fluid cracking unit

Info

Publication number: WO2018166842A1
Application number: PCT/EP2018/055454
Authority: WO
Inventors: Jean-Christophe RABOIN; Romain LESAGE; Hubert Simon
Original assignee: Total Raffinage Chimie
Priority date: 2017-03-16
Filing date: 2018-03-06
Publication date: 2018-09-20
Also published as: FR3063916A1

Abstract

The invention concerns a metal anchoring structure characterised in that it comprises a panel (110) in a single piece, defining a plane and having at least one through-opening (112), said anchoring structure having at least one polygonal-shaped cell with n sides, said cell being defined by a plurality of tabs, including: - at least a first tab (118i) substantially perpendicular to the plane of the panel, on a first side of the plane, - at least a second tab (118i) substantially perpendicular to said plane, on a second side opposite the first side, each tab (118i) being connected to the panel (110) by a folding line (122i) parallel and adjacent to a side of said cell, at least a portion of the tabs (118i) extending from said at least one opening to the folding line (122i), before shaping of the panel. The invention also concerns a panel shaped to produce an anchoring structure.

Description

ANCHORING STRUCTURE FORMED OF A SINGLE CUTTED TOOL FOR ANTI-EROSION COATING, ESPECIALLY FOR PROTECTION OF A WALL OF A CATALYTIC FLUID CRACKING UNIT

The invention relates to an anchor structure formed of a single cut sheet for an anti-erosion coating. Such a coating is more particularly intended to protect an inner or outer wall of a fluid catalytic cracking unit (FCC) enclosure (Fluid Catalytic Cracking).

The invention is particularly suitable for the protection of a wall of an area where there is a risk of erosion due to the circulation of catalyst, such as a cyclone wall, reactor plenum, stripper, riser (upflow reactor), downer (downstream reactor), the walls of

10 standpipes (vertical or substantially vertical tubes), the walls of withdrawal or withdrawal wells, the walls of orifice chambers, or any other wall subjected to erosion.

Fluidized catalytic cracking (FCC) is a chemical process, frequently used in petroleum refineries, whose purpose

15 is to transform heavy cuts with long hydrocarbon chains, for example from the vacuum distillation of petroleum, in lighter cuts and more valuable. The metal walls of the various enclosures of an FCC unit, such as for example a reactor and a regenerator, and the metal walls of the internal equipment located

In the regenerator or the reactor, in particular the cyclones, or the walls mentioned above, can undergo erosion due to the circulation of the catalyst particles, and at the regenerator, a large and rapid corrosion by the combustion gases. . It is therefore necessary to protect them in order to extend their life.

For this purpose, the metal walls are covered with a protective coating. Such coatings are generally made of a composite material, for example a concrete, maintained by an anchoring structure, usually metal. These anchoring structures are first welded to the metal walls and then the cells are filled

30 of composite material, the anchoring structure ensuring the attachment of the latter. Alveolar anchoring structures are generally formed of strips joined in pairs so as to define alveoli. Portions of strips are thus juxtaposed in assembly areas of the structure, this juxtaposition being carried out by applying one against the other the larger surface areas of the strip portions. The juxtaposed portions thus extend in separate parallel planes.

Over time, degradation of this coating is observed, which can lead to a fall of pieces of coating inside the enclosures or internal equipment and require the stop of the installation for the replacement of the coating.

The observed impairments can have several origins depending on the operating conditions of the enclosure concerned.

The reactor or the cyclones and separator located in the reactor, or the transfer line of the products leaving the reactor, are in contact with the gases from the cracking of the feedstock. These gases are introduced between the interstices of the coating and lead to the formation of coke within these interstices, and more particularly at the junction of the strips of the anchoring structure. This formation of coke can lead to significant detachment of the coating during successive cycles of cooling / reheating of the enclosure resulting from stops / restarts (voluntary or not) of the unit: the games existing between the composite material and its structure. The anchors are indeed filled with coke so that these sets of shrinkage can no longer play their role of absorbing the differences in expansion between the anchoring structure and the composite material. This results in the formation of compression lines, cracks, rupture of the weld bead or even detachment of the composite material filling the cells. In particular, the gas penetrates via the cracks and reaches the weld bead, which can lead to the rupture thereof.

In a regenerator or in the internal equipment of a regenerator, in particular cyclones, but also in the line of the fumes at the outlet of the regenerator, or in the orifice chambers, the metal walls are in contact with catalyst particles and with a gas containing, inter alia, oxygen, oxides of carbon, sulfur and nitrogen. This gas penetrates through the interstices of the coating and causes phenomena of sulfurization, carburization and oxidation, particularly at the level of the welds fixing the structure anchoring metal to the metal walls, phenomena that can spread to the entire metal anchor.

Whatever the phenomena of degradation observed, corrosion, in particular by sulphidation, carburization, oxidation, or coke formation, the Applicant has found that these phenomena occur mainly at the level of the metal anchoring structure and / or its connection by welding to the metal walls, and more particularly at the level of the juxtaposed strip portions of the anchoring structure. In particular, without wishing to be bound by a theory, it seems that the diffusion of gas at these junctions up to the metal wall plays a role in the degradation phenomena observed.

The document WO2014 / 009625A1, filed by the applicant, describes a method of producing a coating in which an anchoring structure having hexagonal cells is welded to the wall at least at the junctions between the juxtaposed portions of the strips forming the structure of the structure. anchor. In addition, the composite material completely covers one of the juxtaposed portions of lower height. This makes it possible to limit the introduction and the progression of gaseous species between the juxtaposed portions, and thus to limit degradation of the coating. This solution gives good results, but welding can be tricky to achieve.

Document WO2016 / 071305A1, also filed by the applicant, proposes to cover the anchoring structure of composite material up to a tab provided on the portions of the strips between the juxtaposed portions, so that the upper edge of the portions juxtaposed either entirely covered with composite material, limiting the diffusion of gas at the juxtaposed portions of the anchoring structure. In use, however, there is still a stall of pieces of the composite material.

There is thus a need to improve the resistance of a coating in the face of degradation phenomena, in particular corrosion, in particular by sulfurization, carburization, oxidation, or coke formation.

For this purpose, the object of the invention relates to a metal anchoring structure comprising a single piece sheet defining a plane before any shaping and having at least one through hole, said anchoring structure having at least one polygonal cavity with n sides surrounding said at least one orifice, said cell being defined by a plurality of tabs including:

at least a first tab substantially perpendicular to the plane of the sheet before it is shaped, on a first side of the plane, at least a second tab substantially perpendicular to said plane of the sheet before its shaping, a second opposite side on the first side,

each tab being connected to the sheet by a fold line parallel to and adjacent to one side of said cell, at least a portion of the tabs extending from said at least one orifice to its fold line prior to any shaping of prison.

Each tab is further defined by a plurality of cutting lines.

The anchoring structure according to the invention is thus formed of a single shaped sheet, without juxtaposed portions that can promote the diffusion of corrosive species. In addition, such a structure can be easily made by stamping / shearing or other, and does not require assembly of elements between them. The realization of the anchoring structure according to the present invention is thus relatively simple, fast and inexpensive.

The invention is not limited by a number of legs and by their position. Note that a first tab and a second tab can be connected to the same side of a cell or to different sides of a cell. In contrast, only one type of tab can be connected to one side of a cell. Some sides of an alveolus may also have no legs.

The shape of the cells can be varied, it will nevertheless prefer regular polygonal shapes, including a center or an axis of symmetry.

Advantageously, each tab may have a free edge opposite to said fold line and parallel thereto. This can facilitate the fixing of the anchoring structure to a wall via one of the legs, and further allow to use the other legs as pins when applying a composite material.

According to one embodiment, the anchoring structure may have a single cell. The anchoring structure can then be used to punctual repairs, or for walls with a very constrained environment.

Although it is conceivable that only a few sides of a cell are then connected to a first leg or to a second leg or to a first leg and a second leg, it is nevertheless preferable that a first leg and a second leg are connected to each side of a cell. This may facilitate the distribution of mechanical stresses within the anchoring structure, especially when the shape thereof must be adapted to conform to the shape of a wall to be protected.

According to another embodiment, the anchoring structure may have a plurality of cells of polygonal shape, the cells all having the same number of sides and being arranged so that at least a portion of the cells share each of its sides with an adjacent cell. We then obtain a structure of honeycomb type. Note that the central cells share each of their sides with another adjacent cell, while a cell at the edge of the structure will share only a portion of its sides with another cell.

According to one variant, all the cells may be identical, which may facilitate the construction of the structure and the distribution of the mechanical stresses.

The invention is however not limited to this embodiment, the anchoring structure may thus comprise a first series of cells identical to each other and a second series of cells identical to each other, in particular of the same shape as those of the first series, the cells of the first series being of different dimensions of the cells of the second series, each side of a cell of the first series being adjacent and parallel to one side of a cell of the second series. This can make it possible to produce anchoring structures of variable shapes and dimensions, which can be adapted to many types of walls.

Alternatively or in combination, the cells can be distributed regularly for a better distribution of mechanical stresses. In particular, the cells may be arranged in lines in directions perpendicular to their sides, or, in particular for cells with even number of sides, the cells may be arranged in staggered rows. When several cells are provided, it is also conceivable that only a few sides of a cell are then connected to a first leg or to a second leg or to a first leg and a second leg, it is nevertheless preferable that at least one leg , selected from a first tab and a second tab, is connected to each side of a cell. In the latter case, for two cells having a common side, said common side can be connected to a first leg and a second leg.

Whatever the embodiment, a first leg and a second leg connected to the same side of a cell may be coplanar at least on their central portion along a length of said side. This arrangement can facilitate the folding of the tabs and also reduce the mechanical stresses experienced by the composite material filling the cell.

Alternatively, a first tab and a second tab connected to the same side of a cell may be connected by a strip of material extending between the fold lines of said tabs, said strip of material forming an angle different from an angle right with each of the first and second legs. This can also reduce the mechanical stresses to the composite material filling the cell.

Whatever the embodiment, at least one tab selected from a first tab and a second tab may further have a through opening. This opening makes it possible to improve the anchoring of the structure by allowing the passage of the composite material filling the cell through the opening. The fold line of said at least one tab can advantageously pass through this opening. This limits the length of the edge formed by the fold line, thereby reducing the mechanical stresses experienced by the composite material filling the cell.

The opening may have a shape selected from an oblong shape and a polygonal shape before shaping the sheet. This configuration can limit the formation of constraints in the anchoring structure. The polygonal shape of the opening may in particular have the same number of sides as the cell and its sides may be parallel to the sides of the cell. When a first leg and a second leg are connected to the same side of a cell, a single common through opening at both legs can be provided. The opening is then common to a first leg, to a second adjacent leg and to the strip of material connecting them.

Some cutting lines defining tabs may be simple straight slots whose edges are in contact, or almost in contact, before forming the sheet.

In order to reduce the plastic deformations of the structure during the shaping of the sheet, a cutting line, in particular a slot, defining a tab may widen into an orifice, in particular of circular shape, at the level of the line. folding of the paw, especially at its intersection with it.

An even greater reduction of the plastic deformations can be obtained when this orifice is prolonged by a V-shaped slot extending in the extension of the cutting line and pointing in a direction opposite to the orifice before shaping of the sheet.

Whatever the embodiment and the number of cells of the anchoring structure, the cells may have a number n of sides ranging for example from 3 to 8, preferably from 4 to 6. The 6-sided cells are nevertheless more preferred.

The invention also relates to a one-piece metal sheet defining a plane, characterized in that it has at least one through hole, said sheet comprising a plurality of cutting lines defining a plurality of legs including:

at least one first tab, in particular intended to be folded substantially perpendicularly to the plane of said sheet, of a first side of said plane,

at least one second tab, in particular intended to be folded substantially perpendicularly to the plane of said sheet, of a second side opposite the first side,

each tab being connected to the plate by a single side defining a fold line and at least a portion of the cutting lines defining tabs joining said at least one orifice, and the folding lines associated with the plurality of tabs being arranged according to the at least one n-sided polygon surrounding said at least one orifice.

In particular, the cutting lines that meet the at least one orifice thus open into the latter, in other words, communicate with it. With a sheet as described above, it is possible to achieve an anchoring structure, for example as described above, in particular by forming by stamping, shearing or other. The metal sheet can thus have one or more of the following characteristics:

the sheet has a single orifice, in particular of n-sided polygonal shape whose sides are parallel to the sides of said at least one polygon of fold lines surrounding it. On each side of a polygon formed by the fold lines of several tabs, there may be associated a first tab and a second tab whose fold lines are parallel to said side.

The sheet has a plurality of orifices, in particular of n-sided polygonal shape, the sides of which are parallel to the sides of the at least one polygon of folding lines surrounding it, the polygons all having the same number of sides and being arranged with so that for at least a portion of the polygons, each side of a polygon is parallel to the side of an adjacent polygon. At each side of a polygon, it is possible to associate at least one tab whose fold line is parallel to said side, this tab being selected from a first tab and a second tab. In addition, for two polygons having parallel adjacent sides, one can associate a first tab to one of these sides and associate a second tab to the other of these sides.

- When the sheet has a plurality of orifices, they may be arranged regularly, in rows or staggered as already described.

At least one tab chosen from a first tab and a second tab has a through opening, the fold line of said at least one tab preferably passing through said opening. The opening may have a shape selected from an oblong shape and a polygonal shape. The polygonal shape of the opening may in particular have the same number of sides as the orifice and its sides may be parallel to the sides of the orifice. The opening may be common to a first leg, a second adjacent leg and the strip of material connecting them.

- A cutting line, in particular a slot, defining a tab widens into an orifice, in particular of circular shape, at the fold line, in particular at its intersection with it. This The orifice may be extended by a V-shaped slot extending in the extension of the cutting line and pointing in a direction opposite to the orifice.

The invention further relates to an anti-erosion coating characterized in that it comprises at least one anchoring structure according to the invention embedded in a composite material, for example a concrete, the composite material filling each cell defined by the first and second legs, at least over the entire height of said tabs, in a direction perpendicular to the plane of the sheet before shaping. Advantageously, the composite material completely covers the anchoring structure, thus further limiting the penetration of gas along the legs.

The invention finally relates to an enclosure of a fluid catalytic cracking unit characterized in that it comprises at least one inner or outer wall covered with at least one coating according to the invention, at least one leg of said at least one anchoring structure, selected from a first tab and a second tab, being fixed by welding on the inner or outer wall of the enclosure. This enclosure may in particular be a cyclone chamber, regenerator, disengager or other internal equipment of a fluid catalytic cracking unit to be protected.

The invention is now described with reference to the appended non-limiting drawings, in which:

- Figure 1 is a perspective representation of a sheet for producing an anchoring structure according to an embodiment of the invention;

- Figure 2 is a perspective representation of an anchor structure obtained from the sheet of Figure 1;

- Figure 3 is a partial sectional view of the anchoring structure shown in Figure 2, along the line A-A of Figure 2, the anchoring structure being fixed to a wall and covered with composite material;

- Figure 4 is a perspective representation of a sheet for producing an anchoring structure according to another embodiment of the invention;

FIG. 4b partially shows a plate according to another embodiment: - Figure 5 is a partial sectional view of an anchor structure obtained from the sheet shown in Figure 4, along the line BB of Figure 4, the anchoring structure being attached to a wall and covered with material composite;

- Figure 6 is a plan view of a sheet for producing an anchoring structure according to another embodiment of the invention;

- Figure 7 is a perspective representation of an anchor structure obtained from the sheet of Figure 6;

- Figure 8 is a sectional view along the line C-C of Figure 6; - Figure 9 is a partial perspective representation of a side of a cell of an anchoring structure according to yet another embodiment;

- Figures 10 and 1 1 are flat schematic representations of sheets for producing an anchoring structure according to other embodiments of the invention.

By substantially parallel, perpendicular or at right angle is meant a direction / an angle deviating by not more than ± 20 °, or not more than 10 ° or not more than 5 ° from a direction parallel, perpendicular / from a right angle.

In the present application, "n" is the number of sides of a polygon or cell, each side of a polygon or cell being designated by an index "i", integer ranging from 1 to not.

Figure 1 shows a metal sheet 10 in one piece defining a plane. This sheet 10 has a single through hole 12, which has in the example a polygonal shape, here hexagonal.

The sheet 10 further comprises a plurality of cutting lines 14i to 146 and 16i to 1612, defining tabs 18i and 20i respectively, where i (here 1 to 6) represents the number of sides of the polygon formed by the orifice 12 In the example shown, the cutting lines 14i extend in a direction defined by the center O of the orifice 12 and a vertex of the polygonal shape of the orifice. The other cutting lines are connected in pairs, each pair 16i, I612; I62, I63; 16 ₄ , I 65; 1, 6, I 67; 16th, I69; I610, I611 having a V-shape. The sheet 10 shown in FIG. 1 therefore has an axis of symmetry passing through the center O of the orifice and perpendicular to the plane of the sheet 10.

Each tab 18i and 20i is further connected to the sheet 10 by a fold line 22i and 24i, respectively, here parallel and adjacent to a side of These bending lines are represented symbolically by dashed lines in FIGS. 1 and 2, only a few of these lines being referenced for the sake of clarity. In other words, at each side 13i of the orifice 12 (only two sides of which are referenced in FIG. 1 for the sake of clarity), there is associated a tab 18i and a tab 20i, whose folding lines 22i and 24i are parallel to each other. this side i. the fold lines 22i and 24i thus define two polygons with n sides (n = 6) surrounding the orifice 12. It will be noted that each fold line 22i and 24i connects ends of two opposite cutting lines defining a tab, these lines cutting edge joining the orifice 12 (see FIG.

1), namely extend to the orifice 12. Thus, the cutting lines 14i extend from a fold line 22i to the orifice 12 in which they open. Note further that, in the example, a cutting line 14i terminates at the fold line 22i by an enlarged orifice 15i circular shape before forming the sheet (see Figure 1).

This makes it possible to reduce the stresses during the shaping of the sheet and the legs by reducing the plastic deformations. The invention is however not limited to a circular shape, any other suitable form provided that it is widened, in other words larger than the distance between the edges of the two legs separated by the cutting line. The cut lines 14i are here simple slots.

Note that the tabs 18i extend from an edge of the orifice 12, in other words from a side 13i thereof. Each of the tabs 18i thus has a free edge opposite the folding line 22i and parallel thereto, this free edge being here formed by a side 13i of the orifice 12.

Similarly, each tab 20i has a free edge 21i opposite to its fold line 24i and parallel thereto.

Furthermore, in the example, each cutting line 16i to 16i2 is substantially perpendicular to the fold line of the tab it defines: this allows to fold the tabs 20i at right angles without interfering with each other.

FIG. 2 represents an anchoring structure 1 obtained by shaping the sheet 10 of FIG. 1. The plane formed by the sheet 10 before it is shaped is taken as a reference plane for defining the inclinations of the tabs after folding. (after formatting) in the following description. However, this does not imply that the parts of unfolded sheet remain in this reference plane as detailed below. The tabs 18i, said first legs are erected substantially at right angles to the plane of the sheet 10 before shaping, on one side thereof, while the tabs 20i, said second legs, are erected substantially at right angles to the plane of the sheet 10 (before shaping), on the other side thereof. A cell 2 of polygonal shape is thus obtained whose sides 2i are parallel to the sides 13i of the orifice 12 and to the fold lines 22i and 24i, this cell 2 being defined by the first and second tabs 18i, 20i.

In the example, each side 2i of the cell 2 comprises a first and a second leg 18i, 20i, respectively. The invention is however not limited to a particular number of legs provided that at least one leg (a first or a second) can be used for fixing the structure and at least one other leg used to control the height of the material composite that will fill the cell. One could thus provide that one side out of two of the cell has a first leg

18i, the other sides having second tabs 20i, or alternatively that every other side of the cell has a first tab 18i and a second tab 20i.

The invention is not limited either to a particular tab shape. The shape of the tabs 18i described with reference to Figure 1 has the advantage of limiting material losses during cutting of the sheet. Nevertheless, cut lines 14ine passing through the center O could also be envisaged to define the tabs 18i, which could allow to lighten the anchoring structure. Alternatively or in combination, the orifice 12 could be punctual and then correspond for example to the center O previously defined. It can then be a simple circular orifice or be the junction point of the cutting lines 14i. The legs 18i then extend to the center O, sharing in parts the inner surface of the polygon defined by the fold lines 22i.

FIG. 3 represents the anchoring structure 1 fixed to a metal wall 3 by the free edge 21i of the legs 20i and covered with a composite material 4. It will be noted that, in this example, the legs 18i and 20i are perpendicular to the material strip 19i connecting them, which extends in the plane defined by the sheet before shaping. The invention is however not limited to this arrangement, the material strip 19i being able to form an angle different from a right angle with the associated lugs 18i and 20i, as described for example in the example of the figures 6-8. In this case, after shaping, the material strip 19i no longer extends in the reference plane defined by the sheet before shaping.

Figures 4 and 5 show another embodiment in which the anchoring structure 1 'has a plurality of cells 2', here hexagonal. In the example, these cells 2 'are identical.

The sheet 1 10 thus has a plurality of orifices 1 12 of polygonal shape, the orifices 1 12 having all the same number n of sides and being arranged so that each side 1 13i of an orifice January 12 is parallel to the side of an adjacent orifice.

The orifices 1 12 being all identical, for the sake of clarity, the various references are reported for separate orifices of FIG. 4.

As in the other embodiment, the sheet 1 10 has a plurality of cutting lines 1 14i to 1 146, defining tabs 1 January to 1 186, respectively. In the example shown, the cutting lines

1 14i to 1 146 extend in a direction defined by the center O of each orifice 1 12 and a vertex of the polygonal shape of this orifice 1 12. Similar cutting lines 1 to 14 to 1 146 are provided for each of the orifices 1 12. Like the previous example, a cutting line January 14i widens at its intersection with the fold line 122i and forms an orifice

1 15i here of circular shape before forming the sheet (see fig.1) to reduce plastic deformation during shaping. These plastic deformations can be further reduced by extending these orifices 1 15i by a V-shaped slot 15e extending in the extension of the cutting line 1 14i, and pointing in a direction opposite to the orifice 1 12, such as shown in Figure 4b. Is thus noted that in the configuration shown, shaped slots V 1 15e2, 1 15 _4, 1 15e6 point towards each other so that the amount of material remaining between them is reduced, thus limiting the plastic deformation . Similar V-shaped slots could be envisaged in all the described embodiments.

Each of the lugs 1 18 1 to 1 186 is further connected to the sheet 1 10 by a fold line 1221 to 1226 respectively, parallel and adjacent to one side of the orifice 1 12. These fold lines are represented symbolically by lines dotted in Figure 4 In other words, each side 1 13i (here with i = 1 to 6) of an orifice 1 12, is associated with a lug 1 18i, the fold line 122i is parallel to this side. The lines of fold 122i thus also define polygons with 6 sides surrounding each orifice 1 12.

Note that the tabs 1 18i, before shaping the sheet 1 10, each extend from an edge of the orifice 1 12, in other words from a side 1 13i thereof. Each of the tabs 18i thus has a free edge opposite the fold line 122i and parallel thereto, this free edge being here formed by a side 1 13i of the orifice January 12.

In the example shown, one leg out of two is folded on one side of the sheet 1 10, as shown by the arrows on each leg 1 18i of Figure 4. Thus, the legs 1 18i, 1 183 and 1 18s are folded on the same side, the tabs 1 182, 1 184 and 1 18Ô are folded on the other side, as partially visible in Figure 5.

In this example, a cell 2 'is thus defined by the lugs 1 18i associated with an orifice 1 12 and the lugs 1 18i associated with the orifices adjacent to the orifice 1 12. In other words, a side 2'i of a Cell comprises a lug 18i associated with the orifice 1 12 defining the cell 2 'and a lug 1 18i associated with an orifice 1 12 adjacent.

Figure 5 shows in section the anchoring structure 1 ', obtained by forming the sheet 1 10 described above, attached to a metal wall 3 by the free edge 1 13i legs 1 18i.

As for the other embodiment, the present invention is not limited to a particular shape of the lugs 1 18i. It is thus possible to envisage defining these tabs by V-shaped cuts, such as those used to define the tabs 20i of the other embodiment. In other words, the cutting lines 1 14i then no longer pass through the center O of the orifice 1 12, but they always communicate with the latter. Other forms of cutouts can still be considered. As mentioned in the previous embodiment, in a variant or in combination, the orifice 1 12 may be circular, in particular central and located at the junction point of the cutting lines.

In this embodiment, the lugs 1 18i defining the same side 2'i of a cell are perpendicular to the strip of material 1 19i connecting them, which extends in the plane defined by the sheet before shaping. This strip of material may however not be perpendicular to the legs 1 18i.

Such an arrangement creates sharp edges on the anchoring structure, which can generate mechanical stresses at the level of the composite material filling the cells. Such mechanical stresses can cause the stall of the composite material filling the cells, exposing the metal anchoring structure to the corrosion / coking phenomena described above, which is not sought.

Also, it may be advantageous to limit the formation of sharp edges, as in the embodiment described hereinafter with reference to FIGS. 6 to 8. This embodiment differs from that shown in FIGS. 4 and 5 essentially by the presence of openings 123i and the folding of the legs: the same reference numbers denote identical elements.

Note further that the cutting lines 1 14i are shorter than those shown in Figure 4: the present invention is not limited by a particular length of these lines, provided that one can realize legs and fold .

The openings 123i are through openings formed in the lugs 1 18i. In the example shown, these openings are provided on the legs 1 18i said first legs, all arranged on the same side of the plane defined by the sheet 1 10 before shaping. The invention is however not limited to this embodiment and the openings 123i can be indifferently made:

on the first and / or second legs, in a single continuous opening common to a first leg 1 18i, to a second adjacent tab 1 18i and to the strip of material 1 19i connecting them, so that the corresponding folding areas 122i are are reduced on each of these legs or only some of them.

In the example, these openings 123i are furthermore made at a fold line 122i: thus, the length of the sharp edge formed by this fold line is reduced by the length of the opening 123i, here on about half of its length. The openings could nevertheless be made at a distance from the fold lines.

The openings 123i shown in FIG. 6 are of oblong shape, their greatest length extending parallel to a fold line.

122I. The invention is however not limited to this particular form. Thus, the openings could have a polygonal shape as that of the openings 123i 'and 123 "also shown in Figure 6. The polygonal shape of the opening 123i' has the same number of sides as the orifice 1 12 and sides parallel to the sides of the orifice 1 12. In other words, the polygonal shape of the opening 123i 'is identical to the polygonal shape of the opening 1 12. The invention is however not limited to this particular embodiment, the polygonal shape could have more sides to facilitate the folding tabs, such as the opening 123i "which has two more sides than the opening 123i '.

Note finally that, as shown in Figure 6 for the openings 123i ', 123i ", an opening, whatever its shape, may be common to a first leg 1 18i, to a second adjacent leg 1 18i and to the band of 1 1, as shown in FIG 6, may have openings of different shapes, but for a simpler embodiment, it may be preferable to make identical openings (same shape and same dimensions) on the same. the entire surface of a sheet 1 10. The anchoring structures previously described could be provided with the openings 123i, 123i ', 123i "described above. During the placement of the composite material in the cells, the latter can then pass through the opening or openings and thus improve the anchoring of the structure. In addition, these openings could be made by cutting a tongue of material so that this tongue of material remains attached to the edge of the opening and protrudes from the side 2'i of the cell, favoring the anchoring of the structure in the composite material.

Finally, it will be noted in the example of FIGS. 6-8 that the strip of material 19i connecting two tabs 18i forming one and the same side 21 of a cell forms with each of these tabs an angle other than 90 °, in particular an angle less than 90 °, here an angle of 45 ° (see Figure 8). In other words, after shaping the sheet, this strip of material January 19i is no longer in the reference plane defined by the sheet before shaping.

Another way of reducing the length of the sharp edges formed by the fold lines is to fold legs 18'i connected to the same side 2 "i of a cell so that these legs are coplanar at least on their central portion along a length of said side, as shown in Figure 9. In this case, only two substantially triangular portions of the material strip 1 19'i connecting these legs extend perpendicularly or substantially perpendicular to the legs

The sheets 10 and 1 10 previously described can be made in a simple manner by stamping, shearing, or any other method adapted to make the holes and cutouts and to fold the different legs.

By way of example, the internal dimensions of the hexagonal cells may vary from 4 to 8 cm for a thickness (height) of approximately 1.5 to 3.0 cm, for example 2 cm.

It should be noted that the invention is however not limited by particular dimensions or by a particular shape of the orifices, polygons defined by the fold lines and cells, which can be chosen according to the shape of the walls to be protected. However, it may be easier to make regular shapes (regular polygons) arranged in lines or staggered rows.

Figures 10 and 1 1 show schematically examples of arrangement of sheets 210, 310 respectively to achieve anchoring structures.

In these two embodiments, the cells are square. Each of the sheets 210, 310 is pierced with holes 212, 312 respectively, of square shape. From the corners of these orifices, cutout lines 214i, 314i respectively extend, with i = 1 to n, n = 4. These cutting lines define tabs 218i, 318i which can be folded along fold lines 222i, 322i respectively.

In Figures 10, 1 1, the black dots denote the tabs to be folded above the plane of the sheet, the white dots designating the tabs to be folded below this plane.

The two arrangements are regular, the arrangement of Figure 10 comprising orifices 212 arranged in rows, while the orifices 312 visible in Figure 1 1 are staggered.

It is thus understood that an anchoring structure according to the invention can be produced according to many different arrangements of the cells according to the shape and the arrangement of the cutting and folding lines.

The anchoring structure 1 shown in FIG. 2 can be implemented as follows: the anchoring structure 1 is first optionally shaped in order to marry the metal wall 3 to be protected; for this purpose, the edges 21i of the second tabs 20i are shaped to be in contact with the metal wall 3,

the anchoring structure 1 is then fixed to the metal wall by welding the edges 21i thereto,

then, a composite material 4 is inserted into the cell 2 of the anchoring structure 1 from the metal wall 3 and at least to the free edge 13i of the first legs 18i, as represented in FIG.

The anchoring structure 1 'obtained from the sheet shown in FIG. 4 can be implemented with the same analog, as well as the anchoring structures obtained by shaping the other sheets described.

Whatever its shape, the anchoring structure of the present invention is advantageously made of stainless steel (a stainless steel contains at most 1, 2% by weight of carbon and at least 10.5% by weight of chromium according to the standard EN 10008). In particular, the stainless steel will be chosen to withstand the environment of the enclosure in which the anchor structure is to be used.

The composite material is preferably a material resulting from an assembly of at least two immiscible materials having a high adhesion capacity. Preferably, the composite material is a composite building material such as a concrete, in particular a concrete adapted for use in a fluid catalytic cracking unit.

Claims

1. Anchoring structure (1, l ') characterized in that it comprises a sheet metal (10, 110, 210, 310) in one piece defining a plane before shaping and having at least one orifice (12, 112), said anchoring structure having at least one cell (2, 2 ') of polygonal shape with (n) sides (2i, 2'i) surrounding said at least one orifice (12, 112), said cell being defined by a plurality of tabs themselves defined by a plurality of cutting lines (14i, 16i, 114i, 214i, 314i) of the sheet, of which:

at least one first tab (18i, 118i, 1183, 1185, 218i, 2182, 318i, 3182 is substantially perpendicular to the plane of the sheet before it is shaped, on a first side of the plane,

at least one second tab (20i, 1182, 1184, 1180, 2183, 2184, 3183, 3184) is substantially perpendicular to said plane of the sheet before it is shaped, a second side opposite the first side, each tab (18i , 20i, 118i, 218i, 318i) being connected to the sheet (10,

110, 210, 310) by a fold line (22i, 24i, 122i, 222i, 322i) parallel to and adjacent one side (2i, 2'i) of said cell, at least a portion of the tabs (18i, 118i, 218i, 318i) extending from said at least one orifice to its fold line (22i, 122i, 222i, 322i) prior to any shaping of the sheet.

2. anchoring structure (1, 1 ^ according to claim 1, characterized in that each tab (18i, 20i, 118i, 218i, 318i) has a free edge (13i, 2 li, 113i) opposite its line of folding and parallel to it.

3. anchoring structure (1) according to any one of claims 1 or 2, characterized in that it has a single cell (2).

4. Anchoring structure (1, I ') according to any one of claims 1 to 3, characterized in that a first leg (18i, II81, II83, H85, 218i, 2182, 318i, 318 ₂ ) and a second leg (20i, 118 ₂ ,

1184, 118 ₆ , 2183, 2184, 3183, 3184) are connected to each side (2i, 2 'i) of a cell.

Anchoring structure (1 ') according to any one of claims 1 or 2, characterized in that it has a plurality of cells (2 ') of polygonal shape, the cells all having the same number (n) of sides (2'i) and being arranged so that at least a portion of the cells share each of its sides with an adjacent cell .

6. Anchoring structure (1 ') according to claim 5, characterized in that all the cells (2') are identical.

7. Anchoring structure according to claim 5 or 6, characterized in that the cells (2 ') are distributed regularly.

8. anchoring structure (1 ') according to any one of claims 5 to 7, characterized in that at least one lug (1 18i, 218i,

318i), selected from a first tab and a second tab, is connected to each side (2'i) of a cell.

9. anchoring structure (1 ') according to claim 8, characterized in that, for two cells having a side (2'i) common, the latter is connected to a first leg and a second leg.

10. anchoring structure (1, 1 ') according to claim 4 or 9, characterized in that a first tab and a second tab connected to the same side (2 ") of a cell are coplanar at least on their central portion along a length of said side.

1 1. anchoring structure (1 ') according to claim 4 or 9, characterized in that a first tab and a second tab connected to the same side (2'i) of a cell are connected by a strip of material (1 19i) extending between the fold lines of said tabs, said material strip forming an angle different from a right angle with each of the first and second tabs.

12. anchoring structure according to any one of claims 1 to 1 1, characterized in that at least one tab selected from a first tab and a second tab has a through opening (123i, 123i ', 123i "), the fold line of said at least one tab preferably passing through said opening.

13. Anchoring structure according to claim 12, characterized in that said opening (123i, 123i ', 123i ") has a shape chosen from an oblong shape and a polygonal shape before forming the sheet.

14. Anchoring structure according to claim 12 or 13, characterized in that said opening (123i ', 123i ") is common to a first leg (1 18i), a second adjacent tab (1 18i) and the strip of matter (1 19i) connecting them.

15. anchoring structure according to any one of claims 1 to 14, characterized in that a cutting line (14i, 1 14i) defining a tab widens at the fold line (12i, 122i). and forms an orifice (15i, 1-15i), optionally extended by a V-shaped slit (1 15ei) extending in the extension of the cutting line (1 14i,) and pointing in a direction opposite to the orifice (1 12) before forming the sheet.

16. Metal sheet (10, 1 10, 210, 310) in one piece defining a plane, characterized in that it has at least one orifice (12, 1 12, 212, 312) passing through, said sheet having a plurality of cutting lines (14i, 16i, 14i, 214i, 314i) defining a plurality of tabs including:

at least one first leg (18i, 1 18i, 1 183, 1 185, 218i,

at least one second tab (20i, 1 182, 1 184, 1 180, 2183, 218 ₄ , 318 ₃ , 318 ₄ ),

each tab being connected to the plate by a single side defining a fold line (22i, 24i, 122i, 222i, 322i) and at least a portion of the cutting lines defining tabs joining said at least one orifice (12, 12 , 212, 312),

the fold lines associated with the plurality of tabs being arranged along at least one polygon with n sides surrounding said at least one orifice.

17. Sheet (10, 1, 10, 210, 310) according to claim 16, characterized in that said at least one orifice has a polygonal shape with (n) sides, whose sides are parallel to the sides of said at least one polygon of fold lines surrounding it.

18. Sheet (10, 1 10, 210, 310) according to claim 17, characterized in that it has a plurality of orifices (1 12) each surrounded by associated folding lines arranged along at least one polygon, said polygons all having the same number (n) of sides and being arranged so that for at least a portion of the polygons each side of a polygon is parallel to the side of an adjacent polygon.

19. Sheet (10, 1 10) according to any one of claims 17 to 18, characterized in that at each side of a polygon is associated at least one tab whose fold line is parallel to said side, said leg being selected from a first leg and a second leg.

20. Anti-erosion coating characterized in that it comprises at least one anchoring structure (1, 1 ') according to any one of claims 1 to 15 embedded in a composite material (4), for example a concrete, the composite material filling each cell (2, 2 ') defined by the first and second legs, at least over the entire height of said tabs, in a direction perpendicular to the plane of the sheet before shaping.

21. Enclosure of a fluid catalytic cracking unit characterized in that it comprises at least one wall (3) internal or external coated with at least one coating according to claim 20, at least one leg of said at least one structure anchor, selected from a first tab and a second tab, being fixed by welding on the wall (3) internal or external enclosure.