EP3243027B1 - Fireproof wall, in particular for a combustion furnace - Google Patents

Description

The invention relates to a refractory wall, in particular for a combustion furnace, according to the preamble of patent 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 panels of the protective cover are usually mutually sealed by various measures to some extent to prevent the passage of flue gases. However, in practice this alone can not completely avoid that corrosive flue gases can pass through the protective cover and attack the boiler wall.

So-called ventilated wall systems address this problem by the fact that a protective gas - generally air - is pumped through the space between the boiler wall and the distance superior protective lining. The gas or air is in this case with respect to the combustion chamber under a slight overpressure, which prevents the flue gases from penetrating from the combustion chamber into the wall space and can attack the boiler wall or other metal parts.

A generic refractory wall is for example in the document CH 699 406 A2 described. In this so-called ventilated fire-resistant wall, the Air supply or more generally the supply of inert gas into the space between the boiler wall and its protective cover through a plurality of at the lower end of the refractory wall transversely across these arranged inlet openings in the boiler wall, which from the fireproof side of the refractory wall ago from at least one supply channel be fed. The inlet openings are arranged in the boiler wall in the region of vertically continuous grooves of the plates of the protective covering, so that the gas or the air (from the side) is primarily supplied to these grooves and can distribute over these in the entire wall. For better lateral distribution of the gas or the air, either the panels of the protective covering are themselves provided with transverse channels, or are individual horizontal rows of panels arranged at certain vertical intervals, for example 2-4 m in each case, at a somewhat greater distance from the boiler wall than the remaining panels. so that horizontal cross channels are formed over which the gas or the air can spread over the wall width.

The in the document CH 699 406 A2 described introduction of the gas or air into the space between the boiler wall and the protective lining has, inter alia, the disadvantage that for a sufficient distribution over the wall width cross channels in the plates are required, resulting in an additional design effort either with respect to the plates themselves or with respect their arrangement conditional. Further, the feeding of the gas or air into the plates from the side into the grooves has not proved to be optimal. In addition, the boiler wall must be pierced at a variety of locations of inlet openings.

In view of these disadvantages of this known refractory wall, the invention has for its object to improve a refractory wall of the generic type with respect to the supply of protective gas or air in the space between the boiler wall and the protective cover.

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 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 and stacked in rows and columns refractory plates, each having at least one Plate holder are fixed to the boiler wall, wherein the refractory wall has a ventilated wall portion, in the region between the boiler wall and the protective cover a gap is present, and wherein the refractory wall comprises gas supply means for supplying a protective gas in the intermediate space. The gas supply means comprise a gas distribution channel and at least one gas supply line for supplying protective gas into the gas distribution channel. The Gasverteilkanal is arranged with respect to the installation position of the refractory wall at the lower end of the ventilated wall portion and below the Gasverteilkanals is not a ventilated wall section. The gas distribution channel is arranged with respect to the boiler wall on the same side as the protective cover and extends across the protective cover. The Gasverteilkanal is communicating over its length continuously or at a plurality of discrete locations communicating with the gap between the above him located part of the protective cover and the boiler wall.

The arrangement of a Gasverteilkanals immediately below the ventilated wall section and the direct feed of the inert gas from below from the Gasverteilkanal in the space between the above him part of the protective cover and the boiler wall results in an optimal distribution of the protective gas in the ventilated wall section over the entire wall width.

According to an advantageous embodiment, the gas distribution channel is formed by a gas distribution box into which the at least one gas supply line opens. Such a gas distribution box is easy to implement and quick to install.

Preferably, the gas distribution box has a plurality of gas outlet openings, which in the space between the boiler wall and the Open protective cover. Due to the plurality of gas outlet openings, an optimal protective gas distribution can be achieved.

According to another advantageous embodiment of the gas distribution channel is formed by at least one row of juxtaposed and spaced from the vessel wall refractory plates. This has the advantage that the Gasverteilkanal can be realized without special additional design elements.

Conveniently, the Gasverteilkanal is bounded on one side by the boiler wall. By using the existing boiler wall as Gasverteilkanalwand the gas distribution channel is easier and cheaper to produce.

In an advantageous embodiment variant, the at least one gas supply line opens laterally through the boiler wall into the gas distribution channel. The gas supply line can be made so short.

According to a further advantageous embodiment variant, the at least one gas supply line opens from below into the gas distribution channel, wherein the at least one gas supply line is expediently guided through the boiler wall below the gas distribution channel and then extends upwards between the boiler wall and the protective lining and opens into the gas distribution channel. This has the advantage that the location of the passage of the protective gas through the boiler wall can be determined independently of the position of the Gasverteilkanals.

Advantageously, the boiler wall is designed as a pipe wall with pipes connected by webs.

Conveniently, the boiler wall in the region of the ventilated wall portion above the Gasverteilkanals no gas supply lines for supplying gas into the space.

Fig. 1 -

eine schematische Innenansicht eines Verbrennungsofens mit einer erfindungsgemässen feuerfesten Wand,

Fig. 2 -

eine ausschnittsweise Schnittansicht der feuerfesten Wand nach der Linie II-II der Fig. 1,

Fig. 3 -

eine ausschnittsweise Schnittansicht der feuerfesten Wand nach der Linie III-III der Fig. 2,

Fig. 4 -

eine Ansicht eines Abschnitts der feuerfesten Wand in Richtung des Pfeils IV der Fig. 1,

Fig. 5 -

eine ausschnittsweise Schnittansicht analog Fig. 2 eines zweiten Ausführungsbeispiels der erfindungsgemässen feuerfesten Wand,

Fig. 6 -

eine ausschnittsweise Schnittansicht der feuerfesten Wand nach der Linie VI-VI der Fig. 5,

Fig. 7 -

eine ausschnittsweise Schnittansicht der feuerfesten Wand nach der Linie VII-VII der Fig. 6,

Fig. 8 -

eine ausschnittsweise Schnittansicht analog Fig. 2 eines dritten Ausführungsbeispiels der erfindungsgemässen feuerfesten Wand,

Fig. 9 -

eine ausschnittsweise Schnittansicht der feuerfesten Wand nach der Linie IX-IX der Fig. 8,

Fig. 10 -

eine ausschnittsweise Schnittansicht der feuerfesten Wand nach der Linie X-X der Fig. 9 bzw. der Fig. I2,

Fig. 11 -

eine ausschnittsweise Schnittansicht analog Fig. 2 eines vierten Ausführungsbeispiels der erfindungsgemässen feuerfesten Wand und

Fig. 12 -

eine ausschnittsweise Schnittansicht der feuerfesten Wand nach der Linie XII-XII der Fig. 11.

In the following the invention will be described in more detail with reference to embodiments shown in the drawing. Show it:

Fig. 1 -

FIG. 2 a schematic interior view of a combustion furnace with a refractory wall according to the invention, FIG.

Fig. 2 -

a fragmentary sectional view of the refractory wall according to the line II-II of Fig. 1 .

Fig. 3 -

a partial sectional view of the refractory wall along the line III-III of Fig. 2 .

Fig. 4 -

a view of a portion of the refractory wall in the direction of arrow IV of Fig. 1 .

Fig. 5 -

a partial sectional view analog Fig. 2 a second embodiment of the inventive refractory wall,

Fig. 6 -

a fragmentary sectional view of the refractory wall according to the line VI-VI of Fig. 5 .

Fig. 7 -

a partial sectional view of the refractory wall according to the line VII-VII of Fig. 6 .

Fig. 8 -

a partial sectional view analog Fig. 2 a third embodiment of the inventive refractory wall,

Fig. 9 -

a partial sectional view of the refractory wall according to the line IX-IX of Fig. 8 .

Fig. 10 -

a partial sectional view of the refractory wall along the line XX of Fig. 9 or Fig. I2,

Fig. 11 -

a partial sectional view analog Fig. 2 a fourth embodiment of the inventive refractory wall and

Fig. 12 -

a partial sectional view of the refractory wall according to the line XII-XII of Fig. 11 ,

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, horizontally, height and width refer to the usual vertical inserting position of the refractory wall shown in the drawing.

The Fig. 1 shows schematically a combustion furnace V equipped with a refractory wall W according to the invention. The wall W is subdivided into an upper, ventilated wall section W ₁ and a lower, rear-cast wall section W ₂ . Between the two wall sections W ₁ and W ₂ or at the lower end of the ventilated wall section W ₁ extends over the entire wall width extending Gasverteilkanal K, which will be discussed in more detail below. The wall W includes an in Fig. 1 invisible boiler wall 1 ( Fig. 2 ) and at a distance from this superior protection panel 2, which consists of a plurality of juxtaposed and stacked, arranged in rows and columns refractory plates. The plates in the ventilated wall section W ₁ are designated 21, while the plates of the lower wall section W ₂ are designated 22. The plates 21 and 22 are, for example, ceramic SiC plates, preferably SiC 90 plates having an SiC content of about 90% in the production, which are fire resistant up to over 1000 ° C.

The boiler wall 1 passing through the ventilated wall section W ₁ and the back-poured wall section W ₂ is designed as a tube wall and consists of a multiplicity of vertical tubes 11, which are held together by webs 12 at a mutual distance (see in particular FIG Fig. 4 ). The tubes 11 and the webs 12 are usually made of steel. On the side facing away from the protective casing 2 of the boiler wall 1, a boiler insulation 15 is attached ( Fig. 2 ).

The plates 21 and 22 of the protective cover 2 are attached to the boiler or pipe wall 1 by means (here four in the example) plate mounts 13. The plate mounts 13 are made of heat-resistant steel, eg steel no. 310 to AISI standard or material no. 1.4845 to DIN 17440. The plate mounts 13 essentially each comprise a welded to a web 12 bolts and a nut sitting on the bolt. The plate holders 13 engage in vertically continuous, inwardly widened grooves 21a (FIG. Fig. 4 ) and 22a ( Fig. 10 ) of the plates 21 and 22 and set the distance of the plates 21 and 22 to the tube wall 1 firmly. The plate supports 13 also serve to support the plates 21 and 22 in the vertical direction, the plates 21 and 22 with arranged on them (molded) bridge elements (brackets) 21b and 22b rest on the plate brackets 13. The plates 21 and 22 are movable in the vertical direction to some extent, so as to allow thermally induced expansion or contraction movements. Between the juxtaposed plates 21 and 22 extend undescribed vertical joints and between the superposed plates 21 and 22 are not designated horizontal joints. The joints are sealed in a conventional manner by inserted sealing elements and / or an overlapping formation of the plate edges.

The protective covering 2 is arranged at a certain distance from the boiler wall or pipe wall 1, so that between the plates 21 and 22 of the protective covering 2 and the boiler wall 1 each have a gap 3 and 4 respectively. In the upper, ventilated wall section W ₁ , the gap 3 is empty, in the lower, back-poured wall section W ₂ , the gap 4 with a refractory potting filled. Likewise, in this lower wall portion W ₂ and the vertically continuous grooves 22a of the plates 22 are poured with the potting compound ( Fig. 10 ).

With the exception of the above-mentioned Gasverteilkanals K and the related, yet to be described structural elements, the refractory wall according to the invention in its basic structure conventional refractory walls of this type, so that the skilled person so far requires no further explanation.

The essential difference of the inventive refractory wall over conventional refractory walls of this type is the implementation of the air or general inert gas feed into the ventilated wall section W _{1 of} the refractory wall W. According to the most essential idea of the invention, the refractory wall with this already on mentioned above, on the same side of the boiler wall 1 as the protective cover 2 arranged gas distribution channel K equipped, which extends at the lower end of the ventilated wall portion W ₁ across the width of the wall. The gas distribution channel K is connected via lines still to be explained to an inert gas or air source and stands over its length continuously or at several discrete locations in communicating connection with the gap 3 between the part of the protective covering 2 and the boiler wall 1 above it that from the gas distribution channel K air or inert gas from below directly into the gap 3 between the boiler wall 1 and the plates 21 of the protective panel 2 can be fed.

In the following, four exemplary embodiments of the refractory wall according to the invention are explained in greater detail, which differ primarily only in the formation of the gas distribution channel K and the type of protective gas supply into the gas distribution channel K. The rest of the structure of the refractory wall is in principle in all four embodiments described above, so that will not be discussed in more detail.

In the in the Figures 2-4 illustrated first embodiment of the inventive refractory wall of the gas distribution channel K is formed by a rectangular cross-section Gasverteilkasten 5, which is disposed between the bottom row of plates 21 and the top row of plates 22 and terminates substantially flush with the outer surface of the protective cover 2. On its inside, preferably made of metal Gasverteilkasten 5 is limited by the boiler wall 1 and attached to this (welded). At the upper boundary wall of the gas distribution box 5, this has a plurality of distributed over its entire length (width of the wall) arranged gas outlet openings 51, which open from below into the gap 3 between the boiler wall 1 and the plates 21 of the protective cover 2 and the interior of the Gas distribution box communicating with the gap 3 communicating. For supplying protective gas or air into the gas distribution box 5 or gas distribution channel K, a plurality of gas supply lines 52 are preferably provided, which are passed through the boiler insulation 15 and the boiler wall 1 and open into the interior of the gas distribution box 5. The gas supply lines 52 are connected in operation with a protective gas or air source indicated only symbolically by the arrow Q.

Compared with the above and below the Gasverteilkastens 5 adjacent plates 21 and 22 of the gas distribution box 5 is sealed by means of sealing elements, such as sealing cords 55.

That in the Figures 8-10 illustrated third embodiment of the refractory wall according to the invention differs from the just described first embodiment only by the type of supply of the protective gas in the gas distribution box 5. The gas supply takes place here from below into the gas distribution box 5 by means of several gas supply lines, each having a vertical portion 53a and a have substantially horizontal portion 53b. The vertical sections 53a of the gas supply lines run parallel to the boiler wall 1 through part of the back-poured wall section W ₂ and open from below into the gas distribution box 5 (FIG. Fig. 8 ). The horizontal sections 53b of the gas supply lines pass through similarly to the gas supply lines Fig. 2 the boiler wall l and the boiler insulation (not shown) 15 ( Fig. 10 ). The length of the vertical sections 53a of the gas supply lines may be several meters, as for example Fig. 1 it can be seen where the vertical sections 53a of the gas supply lines extend into the lower region of the lower, back-poured wall section W ₂ .

In the Figures 5-7 shows a second embodiment of the inventive refractory wall is shown, which differs primarily by the implementation of Gasverteilkanals of the two embodiments just described. The here with K 'designated gas distribution channel is here integrated directly into the protective cover 2 and between the boiler wall 1 on the one hand and a number of (non-cast) plates 23 on the other hand formed. Downstream of the Gasverteilkanal K 'is limited by the top row of the back-cast plates 22 of the lower wall portion W ₂ , and above the Gasverteilkanals K immediately adjoins the bottom row of plates 21 of the rear-ventilated wall portion W ₁ .

The plates 23 in the region of the gas distribution channel K 'are preferably of the same design and are fastened to the vessel wall 1 as the plates 22 of the back-poured wall section W ₂ , except that they are thinner (in the direction perpendicular to their surface). Plate holders 13 engage in vertically continuous, inwardly widened grooves 23a (FIG. Fig. 7 ) of the plates 23 and set their distance to the pipe wall 1 firmly. The plate supports 13 also serve to support the plates 23 in the vertical direction, the plates 23 with arranged (molded) bridge elements (consoles) 23 b ( Figures 5 and 6 ) rest on the plate mounts 13. In contrast to the plates 22 of the lower wall portion W ₂ , the plates 23 are not cast-in. They are also less thick or deep formed as the plates 21 of the ventilated wall portion W _first Due to the smaller thickness or depth of the plates 23 in the region of the gas distribution channel K 'their distance from the boiler wall 1 is significantly larger, so that between the row of plates 23 and the boiler wall 1, a relatively large free space exists, which forms the Gasverteilkanal K' in which the protective gas is relatively unhindered over the entire width of the refractory wall can distribute. Of course, it is also possible to use other, in particular even less deep, plates in the region of the gas distribution channel K ', provided that they allow only the formation of a gas distribution channel of sufficiently large cross-sectional dimensions.

The supply of inert gas in the gas distribution channel K 'is carried out as in the embodiment of Figures 2-4 from the side by means of several, the boiler insulation 15 and the boiler wall 1 passing through gas supply lines 52, which open directly into the gas distribution channel K '.

That in the Figures 10-12 illustrated fourth embodiment of the refractory wall according to the invention differs from the third embodiment just described only by the type of supply of the protective gas in the gas distribution channel K '. The gas supply takes place here similar to the second embodiment according to the Figures 8-10 from below into the Gasverteilkanal K 'by means of several gas supply lines, each having a vertical portion 53 a and a substantially horizontal portion 53 b. The vertical sections 53a of the gas supply lines run parallel to the boiler wall 1 through part of the back-poured wall section W ₂ and open from below into the gas distribution channel K '(FIG. Fig. 11 ). The horizontal sections 53b of the gas supply lines pass through similarly to the gas supply lines 52 Fig. 2 the boiler wall 1 and the boiler insulation 15 (not shown) Fig. 10 ).

As already mentioned, the boiler wall of the refractory wall according to the invention does not have to be formed as a tube wall, but may, for example, also be a normal metal wall on which the plate holders 13 are arranged and fastened analogously to the tube wall described above.

Claims (10)

1. Refractory wall (W), in particular for a combustion furnace, with a boiler wall (1) and a refractory protective cladding (2) placed in front at a distance from it, consisting of a plurality of refractory panels (21, 22, 23) arranged in rows and columns next to and above one another, which are fastened to the boiler wall (1) in each case via at least one panel holder (13), wherein the refractory wall (W) has a back-ventilated wall section (W₁), in the region of which a gap (3) is present between the boiler wall (1) and the protective cladding (2), and wherein the refractory wall (W) comprises gas supply means for supplying a protective gas into the gap (3), wherein the gas supply means comprise a gas distribution channel (K; K') and at least one gas supply line (52; 53a, 53b) for supplying protective gas into the gas distribution channel (K; K'), characterized in that the gas distribution channel (K; K') is arranged at the lower end of the back-ventilated wall section (W₁) with respect to the installation position of the refractory wall (W) and there is no back-ventilated wall section below the gas distribution channel (K; K'), wherein the gas distribution channel (K; K') is arranged on the same side as the protective cladding (2) with respect to the boiler wall (1) and extends across the protective cladding (2), and wherein the gas distribution channel (K; K') is continuously over its length or at several discrete points connected in a communicating way with the gap (3) between the part of the protective cladding (2) situated above it and the boiler wall (1).
2. Refractory wall according to claim 1, characterized in that the gas distribution channel (K) is formed by a gas distribution box (5) into which the at least one gas supply line (52; 53a, 53b) opens.
3. Refractory wall according to claim 2, characterized in that the gas distribution box (5) has a plurality of gas outlet openings (51) which open out into the gap (3) between the boiler wall (1) and the protective cladding (2).
4. Refractory wall according to claim 1, characterized in that the gas distribution channel (K') is formed by at least one row of refractory panels (23) arranged next to one another and at a distance from the boiler wall (1).
5. Refractory wall according to one of the preceding claims, characterized in that the gas distribution channel (K; K') is delimited on one side by the boiler wall (1).
6. Refractory wall according to one of the preceding claims, characterized in that the at least one gas supply line (52) opens through the boiler wall (1) into the gas distribution channel (K; K').
7. Refractory wall according to one of claims 1-5, characterized in that the at least one gas supply line (53a, 53b) opens from below into the gas distribution channel (K; K').
8. Refractory wall according to claim 7, characterized in that the at least one gas supply line (53a, 53b) is passed through the boiler wall (1) below the gas distribution channel (K; K') and then runs upwards between the boiler wall (1) and the protective cladding (2) and opens into the gas distribution channel (K; K').
9. Refractory wall according to one of the preceding claims, characterized in that the boiler wall is formed as a tube wall (1) with tubes (11) connected by webs (12).
10. Refractory wall according to one of the preceding claims, characterized in that, in the region of the back-ventilated wall section (W₁) above the gas distribution channel (K, K'), the boiler wall (1) has no gas supply lines for supplying gas into the gap (3).

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