EP3227610B1 - Fireproof wall, in particular for a combustion furnace - Google Patents

Description

The present invention relates to a refractory wall, in particular for a combustion furnace, with a boiler wall, which is formed by a pipe wall made of pipes connected by webs, and a refractory protective covering which is remote from the boiler wall.

Such refractory walls are e.g. used in combustion chambers of combustion plants. The boiler wall is often designed as a metal pipe wall and is usually made of webs connected by pipes. The fire-resistant protective cover, which is suspended at a distance from the pipe wall, is intended to protect the pipe wall from corrosion by flue gases. The refractory protective cover is usually formed in rows and columns next to or above one another arranged plates. Refractory walls are e.g. also used in fluidized bed ovens, where the boiler wall consists of a more or less thick simple metal wall. Again, the boiler wall or metal wall to be protected from corrosion.

The boiler walls and protective coverings are often exposed to temperatures of over 1000 ° C in today's incinerators and experience even with a suitable choice of material due to the large temperature differences of the individual operating conditions strains and contractions. The differences in temperature are generally greater for the protective linings than for the boiler walls themselves, which must be taken into account in the choice of material and / or design of the protective linings, so that the protective linings are not destroyed by greater strains and contractions than the boiler walls. The protective panels or the plates thereof are therefore usually not rigidly attached to the boiler walls, but with play, so that compensating movements are possible parallel to the boiler walls to a limited extent.

The choice of a suitable material for the protective covering makes it possible for the protective covering to be matched to the boiler wall for every operating condition. For boiler walls made of steel, protective linings made of ceramic materials, in particular SiC, have proven successful, although the SiC content can be very different. In practice, SiC masses or SiC plates with a SiC content of 30% -90% are used.

The panels of the protective cover are usually mutually sealed by various measures to some extent to prevent the passage of flue gases. The measures may e.g. Include in the parting lines refractory felt strips and / or a stepped and mutually interlocking formation of the plate edges and / or additional bonding. The mutual sealing of the plates in their joints is structurally relatively complex and also requires a considerable maintenance. There is therefore a need to get along with as few and especially narrow as possible and correspondingly maintenance-free joints in such composed of individual panels protective panels.

The document US 1 955 700 A. discloses a refractory wall for an incinerator having a boiler wall formed by a tube wall of tubes and a refractory protective shroud spaced therefrom of a plurality of refractory plates arranged in rows and columns, each over at least one plate holder are fixed to the vessel wall, wherein each supported on the plate bridge member is supported in a vertical direction on a plate mount per plate, the bridge elements share the height of the plates each in a shorter plate portion and a longer plate portion and that at least some of Plates are arranged in pairs in the vertical direction, and wherein the two plates of each plate pair are arranged abutting each other with their shorter plate portions.

In view of the disadvantages of the known refractory wall systems, the invention has the object to improve a refractory wall of the generic type in that at least a portion of the joints between the plates of the Protective cover disappears or is negligibly narrow.

This object is achieved by the inventive refractory wall, as defined in the independent claim 1. Particularly advantageous developments and refinements of the invention will become apparent from the dependent claims.

The essence of the invention is as follows: A refractory wall, in particular for an incinerator, comprises a boiler wall formed by a tube wall of tubes connected by webs and a refractory protective covering of a plurality of rows and columns spaced therefrom beside or above each other arranged refractory plates, the above each at least one plate holder are fixed to the vessel wall, wherein each plate is supported on the plate arranged bridge element in the vertical direction on a plate mount per plate. The bridge members each divide the height of the panels into a shorter panel section and a longer panel section. At least some of the plates are arranged in pairs in the vertical direction, wherein the two plates of each plate pair are each formed identically and mutually rotated by 180 ° with their shorter plate portions are arranged abutting each other.

The special arrangement of the bridge elements within the plates and the alternate arrangement of the plates with respect to their longer and shorter plate sections, the number of horizontal joints can be greatly reduced. By arranging the two plates of each plate pair in the same direction and mutually rotated by 180 °, it is possible to use the same plate type for the entire protective covering.

Advantageously, the lower plate of each pair of plates are each suspended and the upper plate of each pair of plates are each supported vertically on the plate holders.

By alternately standing and hanging support of the plates ensures that the two plates can be arranged in each case one plate pair virtually joint-free abutting.

Conveniently, each of the lower plate of a plate pair is adjacent the upper plate of an underlying adjacent plate pair, with a parting line between said lower plate and said upper plate. The parting line allows thermal compensation movements of the plates.

According to an alternative embodiment, an intermediate plate is in each case arranged between two vertically adjacent plate pairs, wherein between the lower plate of a pair of plates and the intermediate plate and between the upper Plate of an underlying adjacent plate pair and the intermediate plate each has a parting line.

The joint width of the joints is conveniently 3-12 mm, preferably 5-10 mm. This allows thermal compensation movements of the plates with optimized sealing effort.

Conveniently, the joint width of any butt joints between the abutting shorter plate portions of the two plates of each plate pair is at most 5 mm, preferably at most 3 mm. Such small butt joints are negligible in terms of maintenance.

Conveniently, a space located between the boiler wall and the protective lining is filled with a refractory material. On the one hand, this increases the impermeability to penetrating flue gases and, on the other hand, improves the heat transfer to the boiler wall.

Furthermore, it is expedient if the plates have vertically continuous, inwardly widened grooves in which engage the plate mounts, and preferably when the grooves are also filled with a refractory material. This increases the stability of the protective cover and the heat transfer.

Conveniently, the plates are secured against tilting out of the protective cover. This can be done for example by means of additional Plattenrückhalterungen and is particularly during assembly of the refractory wall or the pouring of the interstices of advantage.

Advantageously, the joints are sealed against the ingress of flue gases.

Conveniently, the plate mounts are attached to the webs of the pipe wall. As a result, the pressure hull is not affected and checks by a recognized expert or authority are therefore superfluous. Another The advantage is that the plate holders are cooled by their connection to the webs.

Fig. 1 -

eine Ansicht der Schutzverkleidung eines Ausführungsbeispiels der erfindungsgemässen feuerfesten Wand nach der Linie I-I der Fig. 3,

Fig. 2 -

einen Schnitt durch die erfindungsgemässe feuerfeste Wand nach der Linie II-II der Fig. 1,

Fig. 3 -

einen Schnitt durch die erfindungsgemässe feuerfeste Wand nach der Linie III-III der Fig. 2 und

Fig. 4-5 -

zwei schematische Skizzen zur Verdeutlichung der Anordnung der Platten der Schutzverkleidung gemäss zwei Ausführungsbeispielen.

In the following the invention will be described in more detail with reference to exemplary embodiments illustrated in the drawings. Show it:

Fig. 1 -

a view of the protective lining of an embodiment of the inventive refractory wall according to the line II of Fig. 3 .

Fig. 2 -

a section through the inventive refractory wall according to the line II-II of Fig. 1 .

Fig. 3 -

a section through the inventive refractory wall along the line III-III of Fig. 2 and

Fig. 4-5 -

two schematic sketches to illustrate the arrangement of the plates of the protective cover according to two embodiments.

The following definition applies to the following description: If reference signs have been given in a figure for the purpose of clarity of drawing, but are not mentioned in the directly related part of the description, reference is made to their explanation in the preceding or following parts of the description. Conversely, less relevant reference numerals are not included in all figures to avoid overcharging graphic for the immediate understanding. For this purpose, reference is made to the other figures.

Location and direction designations, such as top, bottom, side by side, one above the other, laterally, vertically and horizontally, refer to the usual vertical inserting position of the refractory wall shown in the drawing.

The in the Figures 1-3 For example, illustrated refractory wall according to the invention comprises a here designed as a pipe wall 1 boiler wall and at a distance superior protective cover 2, wherein between the boiler or Pipe wall 1 and the protective cover 2, a gap 3 is formed. The boiler or pipe wall 1 consists of a plurality of vertical use in practice pipes 11, which are held together by webs 12 at a mutual distance. The tubes 11 and the webs 12 are usually made of steel. The protective covering 2 comprises a multiplicity of juxtaposed and superimposed refractory plates 21. The plates are, for example, SiC ceramic plates, preferably SiC 90 plates having a SiC content of about 90% in the production, which are fire-resistant up to more than 1000 ° C. are. Each plate 21 is fastened to the tube wall 1 by means of plate holders 22. The plate mounts are made of heat-resistant steel, eg steel no. 310 according to AISI standard or material no. 1.4845 according to DIN 17440. The plate mounts 22 essentially each comprise a threaded bolt 22a welded to a web 12 and a nut 22b seated on the threaded bolt. The plate holders 22 engage in vertically continuous, inwardly widened grooves 21 a of the plates 21 and set the distance of the plates 21 to the tube wall 1 fixed. The plate supports 22 also serve to support (suspend) the plates 21 in the vertical direction, with the plates 21 resting on the plate holders 22 with bridge elements 21b arranged on them (molded). The plates 21 are movable in the vertical direction to some extent, so as to allow thermally induced expansion or contraction movements. Between the juxtaposed plates 21 extend vertical joints 23 (FIG. Fig. 2 ) and between the superimposed plates 21 are horizontal butt joints 24a and parting lines 24b ( FIGS. 1 and 3 ). The space 3 between the boiler or pipe wall 1 and the protective cover 2 and the vertical grooves 21a of the plates 21 are filled with a refractory material (not shown).

The essential difference of the inventive refractory wall over conventional refractory walls of this type is that, seen in the vertical direction, adjacent plates 21 alternately once practically or at least almost without spacing adjacent (butt joints 24a) and the other times have a more pronounced vertical mutual distance (Parting lines 24b). Two immediately adjacent plates 21 each form a pair of plates 21P ( FIGS. 4 and 5 ). This disk configuration is achieved by correspondingly vertically spaced arrangement of the plate holders 22 and by appropriate arrangement of the bridge elements 21b in the plates 21, which in the plates 21 a first row respectively in the lower region of the plates 21 and the plates 21 of the underlying second row respectively in the upper region of the plates 21 are located. The plates 21 with the bridge elements 21b in the lower region are therefore to some extent on the plate mounts 22, while the plates hang with the bridge elements 21b in the upper region to some extent on the plate mounts 22. Not shown retaining elements can optionally ensure that the plates 21 can not tilt out of the protective cover. The distances between the bridge elements 21b in the lower plate region and the lower edge of the plates 21 are significantly smaller than the distances between the same bridge elements 21b and the upper edge of the plates 21. Conversely, the distances between the bridge elements 21b in the upper plate region and the upper edge of Plates 21 significantly smaller than the distances between the same bridge elements 21b and the lower edge of the plates 21. The bridge elements 21b thus divide the height of the plates each asymmetrically into a shorter and a longer vertical plate portion 21c and 21d ( Fig. 3 ). Where plates 21 are adjacent with their respective shorter plate portions 21c, the butt joints 24a have only a slight (almost) vanishing (vertical) joint width, while the parting lines 24b between adjacent longer plate portions 21d are much more pronounced and have a correspondingly larger joint width. The practically negligible joint width of the butt joints 24a is possible because the thermally induced change in length of the (vertically) shorter plate portions 21c is only relatively small, while the thermally induced change in length of the (vertically) longer plate portions 21d is stronger.

The joint width of the butt joints 24a is typically 0-5 mm, preferably 0-3 mm, that of the parting lines 24b is typically 3-12 mm, preferably 5-10 mm.

From the FIGS. 1 and 3 It can be seen that the plates 21 adjacent one another along the butt joints 24a of one plate pair 21P each (with respect to the butt joints 24a) are mirror images. In fact, all the plates 21 are the same, but in the vertical direction, each second plate 21 of a plate pair 21P is disposed 180 ° in the plane of the plate from the first plate 21 of the plate pair 21P, respectively, and rotated normal to the plate. This has the great advantage that the same type of panels 21 can be used for the entire protective covering 2.

In Fig. 5 is shown purely schematically an alternative configuration of the plates of the protective cover. In this case, an intermediate plate or dilatation plate 21Z is arranged in each case between two plate pairs 21P in the vertical direction, which intermediate plate is separated from the two adjacent plate pairs 21P by a parting line 24b. The intermediate plate 21Z is formed the same as all the other plates 21 of the protective cover and also in the same manner to the (not shown in this figure) boiler or tube wall 1 attached.

In particular, the parting lines 24b may be sealed by inserted refractory felt strips and / or a stepped and mutually interlocking formation of the plate edges and / or additional cements, i. be protected against the ingress of flue gases.

Claims (11)

1. Refractory wall, in particular for a combustion furnace, having a vessel wall formed by a tube wall (1) comprising tubes (11) connected by webs (12) and a refractory protective cladding (2) disposed in front of same at a spacing relative thereto and comprising a plurality of refractory plates (21) arranged in rows and columns in mutually juxtaposed or superposed relationship, which are respectively secured by way of at least one plate holder (22) on the vessel wall, wherein for each plate (21) a respective bridge element (21b) arranged on the plate (21) is supported in a vertical direction on a plate holder (22), wherein the bridge elements (21b) divide the height of the plates (21) respectively into a shorter plate portion (21c) and a longer plate portion (21d) and wherein at least some of the plates (21) are arranged in pair-wise relationship in the vertical direction, wherein the two plates (21) of each plate pair (21P) are respectively of an identical configuration and are arranged mutually rotated through 180° in abutting relationship with their shorter plate portions (21c).
2. Refractory wall according to claim 1, characterised in that the lower plate (21) of each pair of plates (21P) is respectively supported in suspended relationship and the upper plate (21) of each pair of plates is respectively supported in standing relationship on the plate holders (22).
3. Refractory wall according to one of the preceding claims, characterised in that the upper plate (21) of a subjacent adjacent plate pair (21P) is respectively adjacent to the lower plate (21) of a plate pair (21P), wherein a separating join (24b) is disposed between said lower plate and said upper plate.
4. Refractory wall according to claim 1 or claim 2, characterised in that an intermediate plate (21Z) is respectively arranged between two vertically adjacent plate pairs (21P), wherein a separating join (24b) is respectively disposed between the lower plate (21) of a plate pair (21P) and the intermediate plate (21Z) and between the upper plate (21) of a subjacent adjacent plate pair (21P) and the intermediate plate (21Z).
5. Refractory wall according to claim 3 or claim 4, characterised in that the join width of the separating joins (24b) is 3-12 mm, preferably 5-10 mm.
6. Refractory wall according to one of claims 3 to 5, characterised in that the separating joins (24b) are sealed to prevent the ingress of flue gases.
7. Refractory wall according to one of the preceding claims, characterised in that the join width of any butt joins (24a) between the abutting shorter plate portions (21c) of the two plates (21) of each plate pair (21P) is respectively at most 5 mm, preferably at most 3 mm.
8. Refractory wall according to one of the preceding claims, characterised in that an intermediate space (3) between the vessel wall and the protective cladding (2) is poured out with a refractory material.
9. Refractory wall according to one of the preceding claims, characterised in that the plates (21) have vertically continuous, inwardly enlarged grooves (21a) into which the plate holders (22) engage, and preferably the grooves (21a) are poured out with a refractory material.
10. Refractory wall according to one of the preceding claims, characterised in that the plates (21) are secured against tilting out of the protective cladding (2).
11. Refractory wall according to one of the preceding claims, characterised in that the plate holders (22) are mounted to the webs (12) of the tube wall (1).

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