Refractory ceramic checker brick

Abstract

The invention relates to refractory ceramic checker brick comprising eight wall sections (10.1-10.8) that adjoin one another at an angle <90°. Said brick is used for example for the checker lining of chambers of a glass-melting furnace.

Description

[0001] The invention relates to a refractory checker block such as is, for example, used for the checker arrangement of chambers in a glass melting furnace.

[0002] Known prismatic refractory hollow blocks of a generic type are described in AT 406 197 B, which describes the present state of development of checker blocks as well as describing earlier embodiments.

[0003] Hollow blocks of the type mentioned, which are also referred to as chimney bricks or hollow chimney blocks, are well proven and widely used. The symmetrical design of the chimney blocks makes it possible to arrange the blocks of adjacent checker planes so that they are offset in relation to each other. In this way, an even design of the checker arrangement and high stability are achieved.

[0004] Over time, deposits (slagging) of extraneous particles which are introduced via the waste gas during heating of the checker arrangement occur on the walls of the checker blocks. This necessitates more or less regular cleaning.

[0005] In the described design of a checker arrangement made of conventional chimney blocks, such cleaning is only possible with difficulty.

[0006] In a so-called grate packing, in which cuboid full blocks are arranged in adjacent planes so as to be offset to each other by 90°, without further ado there are (horizontal) through-passages within a “checker plane”, which through passages make cleaning possible. However, such a grate packing is associated with a disadvantage in that such a checker arrangement has a relatively poor thermal efficiency and poor mechanical stability.

[0007] The invention strives for a symbiosis of the above-mentioned thermal and mechanical parameters, in other words, an option for designing a checker arrangement is to be disclosed that shows how good thermal efficiency as well as the above-mentioned cleaning option can be achieved while providing good mechanical stability.

[0008] In this endeavour, the invention is based on a conventional checker brick, as is for example described in DE 29 34 208 C2 or in AT 406 197 B. Such a hollow brick is essentially rotationally symmetrical as regards its central longitudinal axis (after rotation by 90°, the same geometrical shape results). Such a block is now modified as far as its geometrical shape is concerned, to the extent that it now comprises larger wall sections (wall areas comprising larger surfaces when compared to the state of the art). These larger wall sections can be made with several and/or larger recesses so as to improve the efficiency and/or to admit cleaning equipment.

[0009] Simple dimensional enlargement of the known checker blocks does not lead to the desired outcome because the basic checker design would remain unchanged. Furthermore, thermal efficiency would decrease.

[0010] The idea according to the invention provides for the checker block comprising an essentially rectangular base (instead of the hitherto essentially square base). The geometrical shape of the hollow block is to be such that blocks within a checker plane and in different checker planes are arbitrarily (statistically) combinable in the sense of achieving an even checker design or an even checker density.

[0011] One option of achieving this consists of selecting the length of the block such that it corresponds to double the width of the block minus the wall thickness of a wall. Such a brick is shown and explained in the description of the figures below.

[0012] The following is another design of the geometrical shape of the block: in a so-called “closed arrangement” of the blocks in a (regenerator) checker arrangement, the distance between central longitudinal axes of adjacement blocks in the longitudinal direction is an integral (even) multiple of the distance between central longitudinal axes of adjoining blocks in a transverse direction (perpendicular to the longitudinal direction). In this type of placement, one block of one plane is always placed on a wall section of a block in the plane below it, as will also be explained in more detail in the description of the figures.

[0013] The checker blocks can be arranged side-by-side and perpendicular in relation to each other in a checker plane. This applies correspondingly in relation to the arrangement in a vertical adjacent checker plane, so that overall again a three-dimensional checker design can be constructed which is similar to a design made of conventional checker blocks.

[0014] There is a further advantage in that the checker blocks dimensioned in this way can be combined, within one checker plane, with conventional chimney blocks. In this respect, reference is made to the description of the figures.

[0015] Accordingly, in its most general embodiment, the invention comprises a refractory checker block with the following characteristics:

[0016] eight wall sections, abutting at an angle of <90° in relation to one another;

[0017] the wall sections delimit a space which is open at opposite ends;

[0018] the wall sections provide an upper and lower mutual placement area;

[0019] the length of the checker block corresponds to an even multiple of its width, minus one wall thickness;

[0020] the checker block is designed so as to be symmetrical in relation to a mirror plane which divides the checker block in longitudinal direction.

[0021] Like a conventional checker block, the checker block is ring shaped, wherein the cross-sectional area of the space enclosed by the wall sections now however is essentially rectangular (including the inclined corner areas, it is octagonal in shape). The waste gas (when heating an associated regenerator) or the air (for subsequent thermal absorption) flows through the corresponding hollow spaces in vertical direction, but it also flows (in horizontal direction) through the openings formed in the individual wall sections.

[0022] Due to the elongated design, recesses (openings) comprising a large cross-sectional area, if need be several recesses side-by-side, can be formed in the large (opposite) side areas of the checker block.

[0023] According to one embodiment, the cross-sectional area of the recess(es) is at least 15% of the entire cross-sectional area of the associated wall section. It can easily also be >30, >35, >40, >45, >50, or even >60 or >70% of the entire cross-sectional area of the associated wall section.

[0024] The recess (through opening) can be designed in the shape of a borehole. But it can also be open to a placement area of the checker block, i.e. gate-shaped.

[0025] The large cross-sectional area of the recess in a checker block according to the invention provides the following advantages when compared to the state of the art as mentioned in the introduction:

[0026] It becomes possible, for example by means of lances or rods, to clean the checker arrangement horizontally.

[0027] By reducing the mass fraction of the checker block, the surface on which possible extraneous particles can deposit is also reduced.

[0028] The enlarged openings create increased turbulence of the air/gases conveyed through, thus increasing the thermal transmission to the walls.

[0029] Overall, the checker block has a lower weight of unit volume (kg/m3).

[0030] Because the length and width of the checker block are matched in the sense of a checker design with even distribution, the block can also be combined with “partial-size blocks”, such as “half-size blocks” or “two-cut blocks”, as is shown in the figures below.

[0031] Basically, any geometry of the recess (opening) is possible. According to one embodiment, at least one recess in longitudinal direction of the checker block is of a size which corresponds to at least 50, 60 or 70% of the length of the associated wall area.

[0032] The wall sections which extend perpendicular to the wall sections which extend in longitudinal direction, in other words the shorter wall sections may comprise recesses as well.

[0033] In a checker block whose length corresponds to approximately twice its width, it is however expedient if the cross-sectional area of the recesses in the wall sections which extend in longitudinal direction are approximately twice the size as, at any case greater than, the cross-sectional area of the recesses in the wall sections which are perpendicular thereto (in the direction of the width of the block).

[0034] The described geometrical design of the block makes it possible to take over the inventive idea formulated in AT 406 197 B, namely to provide those wall sections, which extend between the wall sections running in a longitudinal direction of the checker block, i.e. perpendicular to those with a thinner wall thickness. This makes it possible, in the combined arrangement, to create “columns” (hollow spaces) also between adjacent checker blocks of a checker plane, which columns can be used for the purpose of thermal efficiency in that waste gas/air can also be fed therethrough.

[0035] The respective wall sections may, for example, have a wall thickness which is reduced by 15 to 35% when compared to the thickness of other wall sections.

[0036] When designing a complete checker relining arrangement, it is expedient to form elevations and/or indentations in the manner of a tongue and groove system along the areas where blocks are placed so as to be able to provide a safe mechanical fixture for vertically stacked blocks in relation to each other. Concerning design options reference is made to the state of the art mentioned above and being analogously adaptable.

[0037] The new checker blocks can easily be combined with known checker blocks. Thus, at least one checker plane can be designed using the described large checker blocks. If a checker plane above it made from conventional (smaller) checker blocks is built, this can lead to a lumped load (in the corner regions) acting on the wall sections of the (larger) checker blocks below.

[0038] It is thus proposed to shape these checker blocks such that the geometrical moment of the wall sections which extend in longitudinal direction be greater (for example: >50% greater) (I=(b·h)3/12 where b=width, and h=height of the rectangular cross-section) than the geometrical moment of the other wall sections, in particular the wall sections which form the narrow sides of the block. The following measures are possible:

[0039] Widen the wall thickness.

[0040] Avoid recesses (openings) or reduce their cross-sectional area.

[0041] Arrange the recess(es) so that in vertical extension of the expected lumped load, the wall section is free of any recesses.

[0042] Further characteristics of the invention result from the characteristics of the subclaims as well as the other application documents.

[0043] Hereinafter, the invention is explained in more detail by means of various embodiments. The description of the figures contains characteristics which can also be used for the invention either as such or in any desired combinations.

[0044] The following is shown diagrammatically:

[0045] FIG. 1 a : a top view of a checker block;

[0046] FIG. 1 b : a lateral view of the checker block according to FIG. 1a;

[0047] FIG. 1 c a further lateral view of the checker block according to FIG. 1a;

[0048] FIG. 1 d : a perspective view of the checker block according to FIG. 1a;

[0049] FIG. 2: a perspective partial view of a checker arrangement with checker blocks according to FIGS. 1a-d;

[0050] FIG. 3: a top view of a checker plane made of checker blocks according to FIGS. 1a-d;

[0051] FIG. 4: a top view of a multi-storey design of a checker arrangement made of different hollow blocks; and

[0052] FIG. 5: a perspective partial view of an alternative design of a checker arrangement.

[0053] In the figures, identical components or components having identical effect are designated by means of the same reference characters.

[0054] The checker block according to FIGS. 1a, b is designed as follows:

[0055] It comprises a total of eight wall sections 10.1, 10.2 . . . 10.8. The wall sections are parallel in pairs on opposite sides. The wall sections 10.1, 10.5 extend in longitudinal direction L. The wall sections 10.3, 10.7 extend perpendicular to the longitudinal direction L, and thus in “transverse direction” Q. The further wall sections 10.2, 10.4, 10.6 and 10.8 connect the previously described wall regions 10.1, 10.3, 10.5 and 10.7 in the embodiment shown in such a way that adjacent wall sections such as 10.1, 10.2 or 10.5, 10.6 extend at an angle of 45° in relation to each other.

[0056] Overall, this results in an octagonal base, including the space 12 which is enclosed by the wall areas 10.1, 10.2 . . . 10.8, with the horizontal cross-sectional area of said space 12 also being octagonal. The space 12 is open at the top and at the bottom (in the direction of the central longitudinal axis MLA of the block).

[0057] The length l of the block (in this embodiment 398 mm) corresponds to twice the width b (in this embodiment 2×218 mm) minus one wall thickness (in this embodiment 38 mm) of one of the walls 10.1, 10.5 which extend in longitudinal direction L.

[0058] With a “closed arrangement”, the distance between the central longitudinal axes MLA of two blocks adjacent in longitudinal direction corresponds to twice the distance between the central longitudinal axes MLAs of two blocks adjoining in transverse direction.

[0059] In the large wall sections 10.1, 10.5, corresponding recesses 14 are provided which are open to the lower placement area 16 and are gate-shaped in lateral view (FIG. 1b).

[0060] In the embodiment shown, the cross-sectional area of the recess 14 is only slightly smaller than the cross-sectional area of the remaining wall section 10.5. In other words, the cross-sectional area of the recess 14 is approximately 40% of the theoretical total area of the wall section 10.5.

[0061] As is shown in FIG. 1c, the narrow wall sections 10.3, 10.7 also comprise recesses 18, however, their cross-sectional areas are smaller when compared to those of the recesses 14 (in this embodiment approx. 25% smaller).

[0062] While on the placement areas 16 of the wall parts 10.1, 10.5, indentations are arranged at a distance from each other, extending perpendicular to the longitudinal direction L, on the lower placement area 16 of the wall sections 10.3, 10.7, indentations in longitudinal direction L are provided. In the upper placement areas 20 of said wall parts 10.1, 10.3, 10.5 and 10.7, corresponding elevations 22 are arranged, with the indentations and elevations 22 matching so that a positive fit results when the checker blocks are stacked.

[0063] In relation to the plane indicated by the line Q-Q, the block is designed so as to be a mirror inversion, parallel to the central longitudinal axis MLA.

[0064] Checker blocks of the type shown can be made from any desired refractory materials, depending on the application area. To this extent there are no differences compared with conventional checker blocks. This is also true in relation to the method for producing the checker blocks.

[0065] FIG. 2 shows an exemplary checker arrangement made of blocks T according to the invention, in combination with conventional hollow blocks K.

[0066] FIG. 3 shows the basic design of a checker plane made of blocks T according to the invention, with said blocks T being arranged offset in relation to each other “in lines and columns” so as to achieve an even checker density. Adjacent blocks T within one plane abut along the angled-off corner regions 10.2, 10.4, 10.6 or 10.8. Four adjoining blocks (in FIG. 3 these are T1, T2, T3, T4) enclose a space R, whose cross-sectional area corresponds approximately to the cross-sectional area of the space 12 of each block T.

[0067] FIG. 4 shows a design which is analogous to that according to FIG. 3, except that there are blocks in different checker planes, wherein in each case two adjacent blocks cover each other in a wall section, as is also shown in FIG. 2.

[0068] In part of the checker arrangement shown in FIG. 4 (and likewise in FIG. 2), the blocks according to the invention have been replaced by conventional blocks of the design according to DE 29 34 208 C2 or AT 406 197 B respectively. Due to the geometrical shape of the checker blocks according to this invention, these smaller formats can be placed onto the larger formats without any problem. Likewise, again, checker blocks according to the invention can be placed onto conventional checker blocks, in a plane above.

[0069] In particular FIGS. 1b, d and 2 show that the described geometrical shape of the blocks provides a horizontal cleaning option along the channels formed by the openings 14, even in a closed way of placing the blocks.

[0070] FIG. 5 diagrammatically shows the following checker arrangement:

[0071] In a checker plane A, checker blocks similar to those in FIGS. 1a-d are arranged, except that their wall sections 10.1, 10.3, 10.5 and 10.7 are closed so as to increase the geometrical moment of inertia of the wall sections.

[0072] In the plane above (plane B), there are conventional checker blocks T which are essentially supported on the checker block below them by their four corners. This becomes possible as a result of the solid walls 10.1, 10.3, 10.5 and 10.7.

Claims

1. A refractory checker block with the following characteristics: 1.1 eight wall sections (10.1 . . . 10.8), abutting at an angle of <90° in relation to one another; 1.2 the wall sections (10.1 . . . 10.8) delimit a space which is open at opposite ends; 1.3 the wall sections (10.1 . . . 10.8) provide an upper and lower mutual placement area (16, 20); 1.4 the length (l) of the checker block corresponds to an even multiple of its width (b), minus one wall thickness (10.1 . . . 10.8); 1.5 the checker block is designed so as to be symmetrical in relation to a mirror plane which divides the checker block in longitudinal direction (L).

2. The checker block according to claim 1, in which at least those wall sections (10.1, 10.5) which extend in longitudinal direction (L) comprise recesses (14).

3. The checker block according to claim 2, in which the cross-sectional area of a recess (14) is at least 15% of the entire cross-sectional area of the associated wall section (10.1, 10.5).

4. The checker block according to claim 2, in which at least one recess (14) in longitudinal direction of the checker block is of a size which corresponds to at least 50% of the length of the associated wall area.

5. The checker block according to claim 2, in which at least one wall section (10.1, 10.5) which extends in longitudinal direction (L) comprises several recesses (14) spaced apart from each other.

6. The checker block according to claim 1, in which at least one wall section (10.3, 10.7) which extends perpendicular to the wall sections (10.1, 10.5), which extend in longitudinal direction (L), comprises recesses (18).

7. The checker block according to claim 2, in which the cross-sectional area of the recesses (14) in the wall sections (10.1, 10.5) which extend in longitudinal direction is at least twice the size of the cross-sectional area of the recesses (18) in the wall sections (10.3, 10.7) which extend perpendicular thereto.

8. The checker block according to claim 2 or 6, in which the recesses (14, 18) are open to a placement area (16) of the checker block.

9. The checker block according to claim 1, in which the wall sections (10.2, 10.4, 10.6, 10.8), which extend between the wall sections (10.1, 10.3, 10.5, 10.7) which are aligned in longitudinal direction (L) of the checker block and perpendicular thereto, are built of a thinner wall thickness.

10. The checker block according to claim 9, in which the wall sections (10.2, 10.4, 10.6, 10.8), which extend between the wall sections (10.1, 10.3, 10.5, 10.7) which are aligned in longitudinal direction (L) of the checker block and perpendicular thereto, are built in a wall thickness that is thinner by 15 to 35%.

11. The checker block according to claim 1, in which the wall regions (10.1 . . . 10.8) on at least one of their placement areas (16, 20) comprise elevations (22).

12. The checker block according to claim 1, in which the wall regions on at least one of their placement areas comprise indentations.

13. The checker block according to claims 11 and 12, in which the indentations and elevations. (22) are formed for mutual engagement having positive fit.

14. The checker block according to claim 1, in which the wall thickness of the wall sections (10.1, 10.5) which extend in longitudinal direction (L) is greater than the wall thickness of the other wall sections (10.2, 10.3, 10.4, 10.6, 10.7, 10.8).

15. The checker block according to claim 1, in which the geometrical moment of the wall sections (10.1, 10.5) which extend in longitudinal direction (L) is larger than the geometrical moment of the wall sections (10.3, 10.7) which extend perpendicular to them.