CH710497A1 - Refractory wall, in particular for an incinerator. - Google Patents

Abstract

A refractory wall comprises a boiler wall (1) and a refractory protective covering (2) spaced from it and comprising a plurality of juxtaposed refractory plates (21) each attached to the vessel wall via at least one plate support (22) are. Each plate (21) is supported by a bridge element (21b) arranged on the plate (21) in the vertical direction on a plate holder (22). The bridge members (21b) respectively divide the height of the plates (21) into a shorter plate portion (21c) and a longer plate portion (21d). At least some of the plates (21) are arranged in pairs in the vertical direction, with the two plates (21) of each plate pair being arranged abutting each other with their shorter plate sections (21c).

Description

The present invention relates to a refractory wall, in particular for a combustion furnace, with a boiler wall and a superior distance from the boiler wall refractory protective cover according to the preamble of claim 1.

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 panels are often exposed in today's incinerators temperatures of over 1000 ° C 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 cover makes it possible that the protective cover is tuned for each operating condition on the boiler wall. 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 plates of the protective covering 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.

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 to the effect that at least part of the joints between the plates of the protective cover is omitted or is negligibly narrow.

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

The essence of the invention consists in the following: A refractory wall, in particular for a combustion furnace, comprises a boiler wall and at a distance from this superior refractory protective covering of a plurality of juxtaposed in rows and columns refractory plates, the are fastened to the boiler wall via at least one plate holder, with one plate element each supported on the plate being supported in the vertical direction on a plate holder 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, with the two plates of each plate pair being arranged abutting each other with their shorter plate sections.

Due to 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.

Advantageously, the lower plate of each pair of plates each depending suspended and the upper plate of each pair of plates each standing on the plate mounts.

By the 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.

According to a particularly advantageous embodiment, the two plates of each pair of plates are identical and arranged mutually rotated by 180 °. This makes it possible to use the same plate type for the entire protective covering.

Conveniently, each of the lower plate of a plate pair adjacent to the upper plate of an underlying adjacent plate pair, wherein there is 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 disposed between each two vertically adjacent plate pairs, wherein between the lower plate of a plate pair and the intermediate plate and between the upper plate of an underlying adjacent plate pair and the intermediate plate is in each case 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 gap 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 extended grooves, in which engage the plate mounts, and if preferably 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 boiler wall is formed as a pipe wall with pipes connected by webs. A pipe wall is a particularly efficient combination of wall and heat exchanger.

In the following the invention will be described in more detail with reference to embodiments illustrated in the drawings. Show it: <Tb> FIG. 1 <SEP> is a view of the protective lining of an embodiment of the inventive refractory wall according to the line I-I of Fig. 3, <Tb> FIG. 2 <SEP> a section through the inventive refractory wall along the line II-II of Fig. 1, <Tb> FIG. 3 <SEP> a section through the inventive refractory wall along the line III-III of Fig. 2 and <Tb> FIG. 4 - 5 <SEP> two schematic sketches to illustrate the arrangement of the plates of the protective cover according to two embodiments.

For the following description, the following definition applies: If reference numerals are given in a figure for the purpose of graphic clarity, but not mentioned in the directly associated part of the description, reference is made to the explanation thereof in the preceding or following description parts. 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 refractory wall according to the invention shown in FIGS. 1-3, for example, comprises a boiler wall 1 designed here as a pipe wall and a protective casing 2 spaced apart from it, wherein a gap 3 is formed between the boiler or pipe wall 1 and the protective lining 2 is. 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, e.g. Steel No. 310 according to AISI standard or material No. 1.4845 according to DIN 17440. The plate mounts 22 substantially 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 there are vertical joints 23 (Figure 2) and between the plates 21 arranged one above the other there are horizontal butt joints 24a and joints 24b (Figures 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 main difference of the inventive refractory wall over conventional refractory walls of this type is that, viewed in the vertical direction, adjacent plates 21 are alternately once practically or at least almost without spacing adjacent (butt joints 24a) and the other times a more pronounced vertical have mutual distance (parting lines 24b). Two immediately adjacent plates 21 each form a pair of plates 21P (FIGS. 4 and 5). This plate configuration is achieved by arranging the plate holders 22 in a correspondingly vertically spaced arrangement and by arranging the bridge elements 21b in the plates 21, which are in the first row of plates 21 respectively in the lower region of the plates 21 and in the plates 21 of the underlying second series, respectively located in the upper region of the plates 21. 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 (Figure 3). Where plates 21 are adjacent with their respective shorter plate sections 21c, the butt joints 24a have only a slight (almost) vanishing (vertical) joint width, while the parting lines 24b are significantly more pronounced between adjacent longer plate sections 21d 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 (vertical) shorter plate portions 21c is relatively small, while the thermally induced change in length of the (vertical) longer plate portions 21 d 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 Figs. 1 and 3 it can be seen that the longitudinally adjacent the butt joints 24a plates 21 of a plate pair 21P each (with respect to the butt joints 24a) are formed in mirror image. 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, an alternative configuration of the plates of the protective cover is shown purely schematically. 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 cementations, i. be protected against the ingress of flue gases.

As already mentioned, the boiler wall of the inventive refractory wall must not be formed as a tube wall, but may for example be a normal metal wall to which the plate brackets 22 are arranged and fixed in an analogous manner as in the pipe wall described above.

Claims (12)

1. Refractory wall, in particular for a combustion furnace, with a boiler wall (1) and at a distance from this superior fireproof protective covering (2) of a plurality of juxtaposed in rows and columns refractory plates (21), each depending are fastened to the vessel wall via at least one plate holder (22), wherein in each case one plate element (21b) arranged on the plate (21) is supported vertically on a plate holder (22) per plate (21), characterized in that the bridge elements (21b) divide the height of the plates (21) into a shorter plate portion (21c) and a longer plate portion (21d), respectively, and at least some of the plates (21) are arranged vertically in a pair, the two plates (21) each Plate pair (21 P) each with their shorter plate portions (21 c) are arranged abutting each other. 2. Fireproof wall according to claim 1, characterized in that the lower plate (21) of each plate pair (21P) each hanging and the upper plate (21) of each plate pair respectively supported standing on the plate mounts (22). 3. Refractory wall according to one of the preceding claims, characterized in that the two plates (21) of each plate pair (21 P) are formed equal and mutually rotated by 180 °. A refractory wall according to any one of the preceding claims, characterized in that each of the lower plate (21) of a pair of plates (21P) is adjacent the upper plate (21) of an underlying adjacent plate pair (21P) extending between said lower plate and the same upper plate has a parting line (24b). 5. Refractory wall according to one of claims 1 to 3, characterized in that in each case between two vertically adjacent plate pairs (21 P) an intermediate plate (21 Z) is arranged, wherein between the lower plate (21) of a plate pair (21 P) and the intermediate plate (21Z) and between the top plate (21) of an underlying adjacent plate pair (21P) and the intermediate plate (21Z) is a respective parting line (24b). 6. Fireproof wall according to one of the preceding claims, characterized in that the joint width of the parting lines (24b) is 3-12 mm, preferably 5-10 mm. 7. Refractory wall according to one of the preceding claims, characterized in that the joint width of any butt joints (24a) between the abutting shorter plate portions (21c) of the two plates (21) of each plate pair (21P) each at most 5 mm, preferably at most 3 mm , is. 8. Refractory wall according to one of the preceding claims, characterized in that between the boiler wall (1) and the protective covering (2) located intermediate space (3) is poured with a refractory material. 9. Fireproof wall according to one of the preceding claims, characterized in that the plates (21) have vertically continuous, inwardly widened grooves (21 a) into which the plate holders (22) engage, and that preferably the grooves (21 a) with a refractory material poured out. 10. Fireproof wall according to one of the preceding claims, characterized in that the plates (21) are secured against tilting out of the protective covering (2). 11. Refractory wall according to one of the preceding claims, characterized in that the parting lines (24b) are sealed against the ingress of flue gases. 12. Fire-resistant wall according to one of the preceding claims, characterized in that the boiler wall is a pipe wall (1) by webs (12) connected to tubes (11).