WO2000026597A1

WO2000026597A1 - Covering and method for lining a furnace wall and associated brick and anchoring element

Info

Publication number: WO2000026597A1
Application number: PCT/FR1999/002616
Authority: WO
Inventors: Daniel Bravin
Original assignee: Lafarge Refractories
Priority date: 1998-10-30
Filing date: 1999-10-27
Publication date: 2000-05-11
Also published as: EP1131591A1; DE69906120T2; FR2785374A1; FR2785374B1; JP2002529675A; DK1131591T3; DE69906120D1; ATE235033T1; EP1131591B1

Abstract

The invention concerns a covering and a method for lining a furnace wall, as well as the corresponding anchoring element (1) and brick (2). The covering comprises prefabricated refractory anchors (1) fixed in the wall, at least two monolithic refractory masses (3) fixed on the wall by means of the anchoring elements and at least a prefabricated refractory brick (2) arranged between at least two anchoring elements and separating two of the refractory masses, said brick being maintained on the wall by the masses which it separates. The invention is applicable to boilers for incinerating domestic and industrial waste.

Description

Coating and method of lining a wall of a thermal device and associated brick and anchoring

The present invention relates to a coating and to a method of lining a wall of a thermal appliance, as well as to a brick and to a corresponding anchor. The thermal device concerned can in particular be an oven, a boiler or a combustion chamber.

In particular, it finds its applications in the field of boilers, the walls of which are fitted with tubular panels, comprising tubes connected to one another by fins, such as incinerators with grids or with fluidized beds. Such incineration boilers are provided to recover, through the fluid circulating in the tubes, the heat of combustion of household and industrial waste, in order to recover this energy, either in the form of hot water for heating collective buildings, or, with the addition of a turbo alternator, to produce electric current.

However, in order to protect the tubular panels which are subjected to various combined forces: thermal, mechanical and various chemical attacks, it is imperative to protect them by a refractory wall making it possible in this way to ensure protection of the steel tubes, Boiler. It is also imperative to insulate them, so that the thermal load developed by the combustion of waste is not too quickly recovered by the fluids circulating in the boiler. The protection of the tubes of the boiler panels, compulsory, is in particular linked to the need to obtain in the combustion gases a minimum temperature of 850 ° C between the last secondary air supply and the unprotected zone of the boiler tubes, for a minimum of two seconds, the time necessary for the destruction of dioxynes, toxic to humans.

There are linings in refractory concrete whose anchors, in refractory steel, are welded directly either on the tubes or on the fins. These packings use a large amount of anchors. Those based on studs (anchors welded to the tubes), for example, use between 500 and 700 studs per m ² tand is that the anchors of the carp tail type, welded to the fins, are 60 to 80 anchors per m ² . Replacing the panels for maintenance is made very difficult due to the presence of these numerous anchors. On the other hand, the lining by pouring refractory concrete is extremely long, because each panel is executed in situ, one after the other, in order to perfectly delimit its surface.

Other systems, made only with prefabricated refractory bricks hung by steel anchors welded to the fins, are used for the protection of boiler walls. However, the precision of the centers of these hooks is such that these centers define a clearance between the bricks which must be imperatively uniform and which requires very precise mounting because the whole protection of the boiler walls depends on it. In fact, any irregularity in the clearance risks degrading the seals and therefore damaging the seal against gases and chemical corrosion.

European patent EP-B2-080444 discloses a sheet-metal lining furnace comprising a cast refractory lining, fixed by steel anchors which are embedded by casting in prefabricated refractory ceramic anchoring elements. These anchoring elements are molded in a monolithic refractory mass and are fixed to the wall of the furnace by through bolts. This technique makes it easy to replace old coatings for maintenance. However, it has the drawback of having a restricted field of application, and in particular of being unsuitable for coating tubular panels. The present invention relates to a lining covering a wall of a thermal device which can allow easy and quick assembly and disassembly, including on tubular panels.

The lining covering of the invention can thus constitute a continuous protective assembly for tubes of tubular panels, allowing easy replacement of covering plates covering the panels.

Other possible advantages of the invention are:

• intimate contact between the lining and the boiler tubes,

• a smooth, full face on the fireplace side,

• adaptation to curvatures of the wall,

• good durability of the anchors,

• sealing of the coating against gases and chemical corrosion.

The invention also relates to a method of lining a wall of a thermal apparatus, which makes it possible to obtain a coating having the above qualities. The inventive method can allow the protection of a wall of a thermal appliance, including a wall of tubular panels, to be carried out at one time and continuously. This process can allow quick and easy execution.

The invention also relates to a refractory brick and a refractory anchor specifically adapted to the coating and to the lining process of the invention.

To this end, the subject of the invention is a coating for lining a wall of a thermal device, comprising:

• prefabricated refractory anchors attached to the wall, and

• a monolithic refractory mass fixed to the wall by means of anchors.

The coating includes:

At least one prefabricated refractory brick placed on the wall between at least two of the anchors, and

• at least one second monolithic refractory mass, each of the masses being fixed to the wall by at least one of the anchors and being separated from one of the neighboring masses by one of the bricks, the brick being held on the wall by the masses adjacent to this brick.

The wall of the thermal appliance can consist of any surface, such as for example a flat, left, or constituted by the surface of a tubular bundle formed of alternating tubes and fins connecting the tubes. The lining coating is preferably interposed between a heat source, such as an incineration hearth, and the wall. By “monolithic” mass is meant a mass placed in situ on the wall and not preformed. This can be done by pouring, spraying or tamping.

The refractory bricks have the particularity of being maintained on the wall by the masses themselves after hardening. Thus, they do not require any means of attachment to the wall. Their function is to delimit several refractory masses, each of these masses being fixed by one or more anchors.

The lining of the invention is thus specified with regard to the state of the art by the combined use of three types of elements: anchors, bricks and monolithic masses. In particular, compared with patent EP-B2-080444, the coating of the invention introduces the presence of refractory bricks, which can match the shapes of the wall, such as the tube shapes, and exercise the function of separating the refractory masses , while the anchors perform the function of fixing these masses.

Preferably, the wall being a surface of a tubular bundle formed of alternating tubes and fins connecting the tubes, each of the bricks at least partially covers at least one of the tubes by matching the shape of this tube. This embodiment makes it possible in particular to have a very small clearance between the bricks and the tube bundle, which allows the system to be sealed for gases and chemical corrosion. Each of the anchors is then advantageously attached to one of the fins. The assembly is thus facilitated.

In addition, in a particular embodiment where the tube bundle is made up of contiguous tubular panels, the covering is advantageously made up of covering plates, each of the panels being covered by at least one of the plates. It is interesting that each of the tubular panels is covered by a succession of adjoining plates. Preferably, these plates are identical and are offset from one panel to the adjacent panel. Advantageously, at least two of the bricks respectively have two complementary lateral surfaces, arranged side by side on the wall and thus forming a buffer zone between two disjoint parts of the covering. A free space is usefully provided between these two bricks in order to allow a surface expansion between the parts of the corresponding covering. This embodiment makes it possible in particular to separate the coating into coating plates of desired lengths.

The coating preferably comprises flexible joints placed on the bricks, between the bricks and the adjacent refractory masses. Such joints compensate for the expansions of the monolithic masses. They are advantageously pre-glued and elastic at high temperature, and have a thickness which is a function of the quality of the refractory masses adjacent to these joints.

The bricks preferably have a cross section which decreases overall as they move away from the wall. The decrease is understood in the broad sense, the cross section being able to remain constant in one or more parts of the brick. In addition, it is advisable to consider the area delimited by the contour of the cross section of the briq ues, even if certain parts of the brick are hollow, due to protuberances of the wall due for example to tubes. In addition, lower parts of the brick can be truncated, at the level of such protuberances of the wall, the overall decrease property of the cross section remaining despite everything verified.

It is advantageous that the coating comprises a refractory coating of low mechanical resistance applied to the surface of the wall and of the anchors, at least in areas of contact with the refractory masses. This end uit allows better disassembly trim lining in case of repair. Preferably, the coating has thermal properties identical to those of monolithic refractory masses.

Preferably, the covering coating is obtained by pouring the refractory masses into a formwork which comprises an upper surface. This upper surface of the formwork delimits an outer surface of the covering, opposite the wall. The formwork, which serves as a mold for the refractory masses, also keeps the bricks on the wall by pressure and is removed after the refractory masses have hardened. It makes it possible to form the surface of the covering in a smooth and full form.

The formwork notably authorizes the creation of vaults. It also makes it possible to obtain an external surface of the covering which follows the profile of the wall. In this case, the formwork is preferably made of flexible materials. The formwork also makes it possible to introduce curvatures into the exterior surface of the covering, relative to the wall.

According to a preferred embodiment based on the use of a formwork, at least one of the anchors serves as a removable fixing support for a formwork for pouring the masses on the wall. These anchors thus have a double function: hanging the refractory masses and temporarily fixing the upper surface of the formwork.

At least one of these anchors then preferably has a cross section which generally increases from the wall to an external surface of the anchor, the covering comprising means for detachably fixing the formwork to the anchor, which pass through or border this outer surface.

By “cross section” of the anchor, we mean the area delimited by the outline of the cross section of the anchor. Growth is understood here in the broad sense, the cross section being able to be constant in one or more parts of the anchor. The fixing means "crossing the external surface of the anchorage" are means resting on a penetration of the anchorage, such as for example a tapped hole which cooperates with a screw. The fixing means "bordering the external surface of the anchor" are means fixed to the side walls of the anchor.

In a particular embodiment involving anchors having the dual function of fixing the refractory masses and the formwork, the anchors have different lengths depending on their position on the wall and the refractory masses have a variable thickness corresponding to the lengths of the anchors. This embodiment corresponds to the use of flexible formwork, the upper surface of which follows the desired contours, which do not follow the contours of the wall. .

According to another embodiment of the coating obtained by casting the refractory masses in a formwork, this coating comprises means for fixing to the wall of rods passing through the refractory masses and allowing a removable fixing of a formwork for the casting of these masses on the wall . Another embodiment combines the use of removable fixing rods and anchors serving as support and / or fixing to the formwork.

I t is advantageous that the covering comprises at least one removable fixing piece of at least one of the anchors, secured to the wall. Thus, the anchors can be very easily installed for the manufacture of the coating, or removed during disassembly for maintenance.

The anchors are preferably made of steel and / or refractory ceramic.

In a preferred embodiment, at least one of the anchors comprises:

A metallic part, preferably made of steel, attached to the wall and extending into the refractory mass associated with this anchoring up to a first distance from the wall, and

• a ceramic part held on the wall by the metal part extending in this mass up to a second distance from the wall, greater than the first distance, the ceramic part preferentially extending to the outer surface of the mass. Such anchors make it possible to obtain a compromise between steel and ceramic. Indeed, steel anchors have the disadvantage of deteriorating over time, in particular under the effect of substances from the calcination of waste, but allow good fixing to the wall. In the above anchorages, the steel part is present for fixing to the wall, but it can be sufficiently low relative to the external surface of the covering to be protected and thus offer better resistance over time. In a first embodiment of such an anchoring, the steel part penetrates inside the ceramic part. In a second embodiment, the ceramic part includes notches into which the ends of the metal part are introduced. According to an advantageous embodiment, the refractory masses consist of refractory concrete. In another embodiment, which is advantageous in particular in the presence of acid gases or fumes, the refractory masses are constituted by refractory plastic masses. The invention also relates to a prefabricated refractory brick for lining a wall of a thermal appliance. According to the invention, the brick has a shape allowing this brick to be maintained on the wall by hardening of at least one monolithic refractory mass. This definition notably excludes any parallelepipedic brick.

Preferably, the brick according to the invention is such that it is suitable for one or more of the embodiments of the coating according to the invention. In particular, the brick advantageously has: • a shape that partially matches the shape of a tube and / or

• a cross section g generally decreasing from one face to another opposite face of the brick.

The invention also relates to a prefabricated refractory anchor for garn issage of a wall of a thermal device. According to the invention, the anchor serves as a removable fixing support for a formwork.

Compared to known anchors, the anchor according to the invention therefore has a shape allowing it to serve as a support and it is provided with specific fixing means.

Preferably, the anchoring according to the invention is suitable for one or more of the embodiments of the covering according to the invention. In particular, it is advantageous for the anchor to have a generally increasing cross-section from a base intended for attachment to the wall to an outer surface of this anchor and to be equipped with attachment means, removable from a formwork at the anchoring, crossing or bordering this exterior surface.

The invention also relates to a method of lining a wall of a thermal appliance, in which:

• prefabricated refractory anchors are attached to the wall, and

• a refractory mass is placed on the wall, this mass being fixed by means of the anchors.

According to the invention: • before the installation of the refractory mass, there is at least one prefabricated refractory brick on the wall between at least two of the anchors, and

• at least one second refractory mass is put in place on the wall, each of these masses being fixed to the wall by at least one of the anchors and two of these masses being poured respectively on either side of this brick and now this brick on the wall after hardening.

The lining method according to the invention preferably makes it possible to manufacture a lining coating according to one or more of the embodiments of the invention.

The invention will be better understood using specific embodiments, presented with reference to the appended figures in which: Figure 1 shows in section ll a partial cross section of a tubular panel covered with a lining covering according to the invention.

Fig ure 2 shows a front view of the tubular panel and the lining of Figure 1.

Figure 3 shows in more detail a first embodiment of an anchoring of the coating shown in Figures 1 and 2, with placement of a formwork on the coating.

Figure 4 shows in detail a second embodiment of an anchoring of the coating of Figures 1 and 2, with placement of a formwork on the coating. .

Figure 5 shows in detail refractory bricks of the coating of Figures 1 and 2.

Figure 6 shows, in front view, two adjacent tubular panels each covered with a lining covering according to the invention, similar to that illustrated in Figures 1 to 5.

Figure 7 illustrates a third embodiment of an anchor according to the invention, in side view. Fig ure 8 shows in section VI I I-VI I I the third embodiment of an anchoring according to Figure 7.

Figure 9 shows a fourth embodiment of an anchor according to the invention.

Figure 10 shows another embodiment of a lining covering of a tubular panel, comprising the anchors of the third and q uth embodiments of Figures 7 to 9, as well as fixing rods.

Fig ure 1 1 shows in partial XI-XI section the tubular panel with coating of Fig ure 10, covered with a formwork. Figure 12 shows in partial section XI I-XI I a tubular panel covered with another embodiment of a lining covering according to the invention.

Figure 13 shows a front view of the tubular panel covered with the lining of Figure 12. Figure 14 shows in front view two adjacent tubular panels covered with lining coverings similar to those of Fig ures 12 and 1 3.

In what follows, the technical teaching of figures must be considered as complementary to the technical teaching of the description.

Identical or similar elements of different embodiments are designated by the same reference numerals. In addition, similar elements are generally specified by suffixes A to E supplementing the numerical references: the suffixes A to D refer respectively to four embodiments of the anchors and the suffixes A and E refer to two embodiments of the bricks . In addition, in the first embodiment of the bricks, the suffixes A and A 'apply respectively to complementary bricks forming couples.

A tubular panel made up of tubes 14 connected to each other by welded fins 4 forms a wall 16 oriented towards a thermal hearth (Figures 1 and 2). Fluids, such as water, circulate inside the tubes 14. A lining covering, covering the tubular panel, comprises prefabricated refractory anchors 1, prefabricated refractory bricks and monolithic refractory masses 3 of refractory concrete , poured in situ. The lining covering is distributed in covering plates 20, placed side by side along the panel perpendicular to the direction of the tubes 14, according to a succession of plates 2O _N1 , 2O _s and 20 _{i + 1} separated by seals 18. As for example, the seals 18 are 3 mm wide. Each cover plate 20 is rectangular and has, for example, sides having a length of 700 mm.

In a first embodiment of the anchors 1, referenced 1 A and shown in Figure 3, the anchor 1 A comprises a steel part 31 A and a ceramic part 32A. The steel part 31 A includes a threaded branch 35A and a connecting piece 15A of approximately conical and hollow shape, having: a top secured to the threaded branch 35A. The connecting piece 15A is incorporated in the ceramic part 32A. The latter constitutes a solid anchor head having an approximately frustoconical shape, having a small base 39A at the level of the threaded branch 35A and a large base forming a flat outer surface 36A of the anchor 1 A, beyond the part. 15A connector. The outer surface 36A is distant from the connecting piece 1 5A by a distance d _A sufficient to protect the metal part 31 A from harmful infiltration from the outer surface 36A. The threaded branch 35A is fixed to the wall 16 by means of a fixing piece 5 welded to one of the fins 4. This fixing piece 5, for example of the nut type, comprises an internal thread for screwing the threaded branch 35A .

The anchoring being approximately of revolution around an axis 70A, the ceramic part 32A is provided with a blind hole 37A made along the axis 70A of the anchor 1 A, from the external surface 36A. This blind hole 37A is intended to accommodate a fixing pin 10A for the introduction of a fixing screw 9A.

In another embodiment of the anchors 1, shown in Figure 4 and referenced 1 B, elements identical or similar to those of the anchor 1 A have the same reference numerals with the suffix B instead of A. L ' anchor 1 B differs from anchor 1 A in that the blind hole 37B extends approximately to the top of the connecting piece 15B, the fixing pin 10B being intended to contain a threaded rod 1 3 projecting from the external surface 36B so as to be able to receive a nut 38.

In the present embodiment, the bricks 2 are provided in pairs, each pair comprising two bricks 2 referenced 2A and 2A 'respectively (Figure 5). The bricks 2A and 2A 'respectively have first surfaces 43 and 44 of complementary shape, designed to be placed side by side transversely to the wall 16. These first surfaces 43 and 44 are preferably flat and, more precisely, are advantageously parallel to a middle plane 71 between the two surfaces 43 and 44, which is perpendicular to the wall 16. The bricks 2A and 2A 'also include second surfaces 45 and 46 having a shape matching the outline of respectively two of the tubes 14 adjacent to these surfaces 45 and 46. They also include respectively of the third surfaces 47 and 48, opposite respectively to the first surfaces 43 and 44 and forming an inclined portion 17 producing a narrowing of the briq ues 2A and 2A 'by moving away from the second surfaces 45 and 46. The third surfaces 47 and 48 are extended by q uatrieme surfaces 49 and 50, approximately parallel to the second surfaces 43 and 44. The bricks 2A and 2A 'also include fifth surfaces 51 and 52 respectively opposite the second surfaces 45 and 46 and preferably flat. The first surfaces 43 and 44 and the fifth surfaces 51 and 52 are truncated at their intersection, so as to form sixth surfaces of the chamfer type 53 and 54.

Preferably, the briq ues 2A and 2A 'are identical and are arranged symmetrically with respect to the plane 71.

Flexible joints 1 1 are pre-glued on the fourth surfaces 49 and 50 of the bricks 2A and 2A '. These seals 11 are preferably made of refractory materials which remain elastic at high temperature and they are intended to compensate for dilations of the plates 20.

To manufacture the lining covering according to a first embodiment corresponding to the preceding embodiments, the procedure is as follows. First of all, the fastening parts 5 are welded onto part of the fins 4 of the tubular panel to be trimmed. The fixing pieces 5 are distributed regularly within each part of the wall 16 intended to be covered by one of the covering plates 20 (Figure 2). I ls preferably form a network of lines parallel and perpendicular to the tubes 14. Perpendicular to the tubes 14, they are for example welded to a fin 4 on two (Figures 1 and 2). Then applied with a brush to the tubes 14 and the fins 4 a refractory coating of low mechanical resistance, preferably having thermal properties identiq ues to that of the refractory concrete 3 to be put in place. The cement is preferably applied selectively in zones 12 intended to be in contact with the refractory concrete 3.

The prefabricated anchors 1 are then mounted by screwing into the fixing pieces 5. Beforehand, the threaded branch 35 of the anchors 1 A or 1 B is coated in a protective tube 6 such as a cardboard tube, in order to avoid that the refractory concrete 3 comes to block the threaded branch 35A (Figures 3 and 4). Using a brush, the refractory coating is applied in a thin layer to the anchors 1 A or 1 B, in zones 12 intended to be in contact with the refractory concrete 3. The application of the refractory coating on the anchor 1 must make it possible to unscrew this anchor 1 during disassembly.

There are also the bricks 2 in pairs 2A and 2A ', at the junctions 18 provided between the covering plates 20 (Figures 1 and 2). Each of the pairs of bricks 2A and 2A 'partially covers two neighboring tubes 14 (Figure 5), the first surfaces 43 and 44 of the bricks 2A and 2A' having between them a free space 56 intended to form the joint 1 8 between the two plates 20 bounded respectively by the two bricks 2A and 2A '. The chamfers 53 and 54 delimit a triangular upper free space 55, intended to facilitate the dismantling of the plates 20. In addition, the second lower surfaces 45 and 46 leave between the bricks 2A and 2A 'and the fin 4 included between the tubes 14 covered by the briq ues 2A and 2A ', a lower free space 57, in which, according to a particular mode of implementation, it is advantageous to apply the refractory coating beforehand.

A formwork 7 is then positioned over the anchors 1 and the bricks 2. This formwork 7 is supported on the outer surface 36 of the anchors 1 A and 1 B and on the fifth surfaces 51 and 52 of the bricks 2A and 2A '. The formwork 7 is fixed to each of the anchors 1 A by applying a pressure plate 8 to the formwork 7, above the anchor 1 A concerned and by blocking the formwork 7 by a fixing screw 9A passing through the pressure plate 8 and the formwork 7 and fitting into the dowel 10A of the anchor 1 A ( Fig ure 3). Similarly, the formwork 7 is fixed to each of the anchors 1 B by means of the threaded rod 13 positioned in the dowel 10B, which passes through the formwork 7 and a pressure plate 8, by tightening a nut 38 over the plate pressure 8 (Figure 4). The pressure plates 8 are for example steel washers.

The formwork 7 is strong enough to hold the masses 3 of refractory concrete to be poured and is preferably made of flexible materials. It is advantageously transparent, so as to be able to visually follow the correct positioning of the masses 3 of refractory concrete. In other embodiments, the formwork is made of wood or steel.

The formwork thus positioned and fixed maintains the bricks in position 2. The masses 3 of refractory concrete are then put in place in the formwork 7. After hardening, the screws 9A, the nuts 38, the threaded rods 13, the pressure plates 8 and the formwork 7 and the outer surface 26 of the lining covering is obtained, consisting of a smooth and full face. The pins 1 0, not resistant to fire, are destined to disappear by the action of the temperature of the hearth.

In the presence of several contiguous tubular panels, separated by seals 1 9 having for example 9 mm thick (Figure 6), there is advantageously produced a succession of covering plates 20 and 21 respectively for each of the tubular panels. The joints 1 8 between the covering plates of two neighboring panels are then advantageously offset.

According to a third embodiment of the anchors 1, referenced 1 C and shown in Figures 7 and 8, the anchor 1 C comprises a steel part 31 C, which has a shape substantially hollow frustoconical having a small base 71 and two inner edges 73 and 74 opposite the small base 71. The anchor 1 C also comprises a ceramic part 32C of substantially solid frustoconical shape, provided with two lateral notches 33 and 34. The ceramic part 32C is held on the steel part 31 C by introduction of the internal edges 73 and 74 respectively in the notches 33 and 34, the ceramic part 32C having a small base 39C disposed opposite the small base 71 of the steel part 31 C. The anchors 1 C are fixed to the tubular panel by welding the small base 71 on one of the fins 4. The anchor 1 C retains the role of supporting the formwork 7 by the flat outer surface 36C of its ceramic part 32C, but does not have a function of fixing the formwork 7. A fourth embodiment of anchoring 1, referenced 1 D and shown in Figure 9, involves only a steel part 31 D and not a ceramic part. The anchor 1 D, having substantially a cut shape, is welded by a foot 75 to one of the fins 4. The anchors 1 D have dimensions such that once welded, they remain distant from the formwork 7, therefore the upper surface 26 of the lining covering. Thus, these anchors 1 D serve exclusively for the attachment of refractory concrete 3 to the tube bundle.

In a particular implementation of the lining process, using the anchors 1 C and 1 D, the anchors 1 C and 1 D are alternately welded parallel to the tubes 14 on the fins 4 (FIGS. 1 0 and 1 1).

In addition, the formwork 7 is fixed using threaded rods 61 extending transversely to the wall 16 and having a length sufficient to cover the distance between the wall 16 and the formwork 7, for the introduction of the masses. 3 of refractory concrete. The rods 61 cooperate with fixing nuts 60, welded to some of the fins 4 at the joints 1 9 between tubular panels and intended to receive the threaded rods 61, as well as with clamping nuts 62 intended to tighten the formwork 7- by pressure. By way of example, the fixing nuts 60, the threaded rods 61 and the clamping nuts 62 are of the type sold under the name M 12.

For the implementation of the coating process, one begins by welding the fixing nuts 60 and the anchors 1 C and 1 D, the refractory coating is applied as in the previous embodiments and the rods 61 are tightened in the fixing nuts 60. The formwork 7 is then placed in abutment on the anchors 1 C above the tubular panel to be trimmed, and it is fixed by means of threaded rods 61, by having pressure plates 8 similar to those described higher on the formwork 7, above the threaded rods 61 and tightening the formwork 7 against the ceramic parts 32C of the anchors 1 C by screwing the nuts 62 on the threaded rods 61 against the pressure plates 8.

The refractory concrete 3 is then poured into the formwork 7, then, after hardening, the clamping nuts 62, the pressure plates 8, the formwork 7 and the threaded rods 61 are removed. Coating plates 22 are thus obtained having an outer surface 26 in the form of a smooth and full face.

In another embodiment of the lining covering shown in FIGS. 12 and 13, the bricks 2, referenced 2E, are provided to be placed each directly between two masses 3 of refractory concrete, referenced 3E, and at their contact, perpendicularly to tubes 14.

Each of the bricks 2E has a lower surface 81 which matches at least partially the shape of one or more of the tubes 14, and preferably of three of the tubes 14. The brick 2E also has lateral surfaces 82 and 82 inclined so as to produce a shrinkage of the brick 2E away from the lower surface 81. The inclined lateral surfaces 82 and 83 are extended by lateral surfaces 84 and 85, advantageously perpendicular to a mean plane of the lower surface 81. The lateral surfaces 84 and 85 are covered with flexible joints 1 1. The 2E brick also has an upper surface -.86, preferably plane and parallel to this mean plane. In addition, the brick 2E is preferably symmetrical with respect to a median plane 72 perpendicular to this mean plane.

For the manufacture of a lining coating with the bricks 2E, the procedure is similar to the previous embodiments, but by alternating one of the bricks 2E with one or more of the anchors 1, perpendicular to the tubes 14. Advantageously, there is a single anchor 1 between two of the bricks 2E, perpendicular to the direction of the tubes 14. Since the briquets 2E do not form a disjunction between the masses 3 E of refractory concrete, a single covering plate 23 is thus obtained on the tubular panel to be lined .

In the presence of several contiguous tubular panels, each of them is covered with a covering plate 23 or 24 (FIG. 14), the rows of the anchors 1 parallel to the tubes 14 being preferably alternated from a covering plate to the other.

The invention covers any combination of the embodiments and implementation described above, in particular the combined use of any of the anchors 1 with any of the bricks 2.

The number of anchors 1 is chosen low enough to minimize the number of welds on the wall 16 but correctly maintain the masses 3 of refractory concrete. In general, the anchorages 1 can be relatively distant perpendicular to the direction of the tubes 14 but must be more numerous, and preferably regularly distributed, parallel to the direction of the tubes 14.

Claims

INCOME FROM ICATI ONS

1. Coating for lining a wall of a thermal appliance, comprising:

• prefabricated refractory anchors (1) attached to the wall (16), and

• a monolithic refractory mass (3) fixed to the wall (16) by means of the anchors (1), characterized in that the coating comprises:

• at least one prefabricated refractory brick (2) disposed on the wall (16) between at least two of the anchors (1) and

• at least a second monolithic refractory mass (3), each of said masses (3) being fixed to the wall (16) by at least one of the anchors (1) and being separated from one of said neighboring masses (3) by one of said bricks (2), said brick (2) being held on the wall (16) by said masses (3) adjacent to said brick (2).

2. Lining covering according to claim 1, characterized in that the wall (16) being a surface of a tubular bundle formed by alternating tubes (14) and fins (4) connecting the tubes (14) , each of the bricks (3) at least partially covers at least one of the tubes (14) by matching the shape of said tube (14).

3. Upholstery coating according to claim 2, characterized in that each of the anchors (1) is attached to one of the fins (4).

4. Upholstery covering according to one of claims 2 or 3, characterized in that the tube bundle consisting of contiguous tubular panels, the covering consists of covering plates (20-24), each of said panels being covered by at minus one of the plates (20-24).

5. Upholstery covering according to any one of claims 1 to 4, characterized in that at least two of the bricks (2A, 2A ') respectively have two complementary lateral surfaces (43, 44), arranged side by side on the wall (16), and thereby forming a buffer zone (56) between two disjoint parts (20, 21, 22) of the coating.

6. lining coating according to any one of claims 1 to 5, characterized in that it comprises flexible joints (1 1) placed on the bricks (2), between the bricks (2) and the masses (3) adjacent refractories.

7. lining coating according to any one of claims 1 to 6, characterized in that the bricks (2) have a cross section which decreases overall away from the wall (16).

8. lining coating according to any one of claims 1 to 7, characterized in that it comprises a refractory coating applied to the surface of the wall (16) and anchors (1), at least in contact zones ( 12) with the refractory masses (3).

9. Lining covering according to any one of claims 1 to 8, characterized in that at least one of the anchors (1A, 1 B) serves as a removable fixing support for a formwork (7) for pouring said masses (3) on the wall (16).

10. Upholstery covering according to claim 9, characterized in that at least one of the anchors (3A, 3B) has a cross section (3) which grows overall from the wall (16) to an outer surface ( 36A, 36B) of said anchor (1 A, 1 B) and in that the covering comprises removable fixing means (8-1 0, 37, 38) from the formwork (7) to said anchor (1 A, 1 B), crossing or bordering said outer surface (36A, 36B).

1 1. Lining covering according to one of claims 9 or 10, characterized in that the anchors (1) have different lengths depending on their position on the wall (16) and in that the refractory masses (3) have a corresponding variable thickness to said lengths of the anchors (1).

12. Lining covering according to any one of claims 1 to 1 1, characterized in that it comprises fixing means (60) to the wall (16) of rods (61) passing through the masses (3) and allowing a removable fixing of a formwork (7) for the casting of the masses (3) on the wall (16).

1 3. Upholstery covering according to any one of resells 1 to 12, characterized in that it comprises at least one removable fixing part (5) of at least one of the anchorages (1 A, 1 B), secured to the wall (16).

14. Lining covering according to any one of claims 1 to 13, characterized in that at least one of the anchors (1 A-1 C) comprises: • a metal part (31) preferably made of steel, attached to the wall (16) and extending in the refractory mass (3) associated with said anchors (1 A-AC) up to a first distance from the wall (16), and

• a ceramic part (32) held at the wall (16) by the metal part (31) and extending in said mass (3) up to a second distance from the wall, greater than the first distance, said ceramic part (32) preferably extending to the outer surface (36) of said mass (3).

1 5. lining coating according to any one of claims 1 to 14, characterized in that said masses (3) are constituted by u refractory concrete.

16. Prefabricated refractory brick (2) for lining a wall (16) of a thermal device, characterized in that it has a shape allowing said brick (2) to be held on the wall (16) by hardening of at least one monolithic refractory mass (3) and in that it is suitable for the coating according to any one of claims 1 to 15.

17. Prefabricated refractory anchor (1) for lining a wall (16) of a thermal device, characterized in that it serves as a removable fixing support for a formwork and in that it is suitable for coating according to l any of claims 1 to 15.

18. A method of lining a wall (16) of a thermal appliance, in which:

• prefabricated refractory anchors (1) are attached to the wall (16), and • a refractory mass (3) is put in place on the wall (16), said mass (3) being fixed by means of the anchors (1), characterized in that:

Before placing said mass (3), at least one prefabricated refractory brick (2) is placed on the wall (16) between at least two of the anchors (1), and

• at least one second refractory mass (3) is put in place on the wall (16), each of said masses (3) being fixed to the wall (16) by at least one of the anchors (1) and two of said masses (3 ) being poured respectively on either side of said brick (1) and maintaining said brick (2) on the wall (16) after hardening.

1 9. A lining method according to claim 20, characterized in that it makes it possible to manufacture a lining coating according to any one of claims 1 to 15.