Refractory roof and brick therefor

Abstract

 A refractory roof comprises refractory bricks (A, B, C) arranged in parallel rows (4-6) and having side surfaces connecting with each other, and a superjacent supporting structure for directly supporting some of the bricks, which in turn support the remaining bricks. Each brick (A, B, C) is quadrilateral in planes which are essentially parallel with the roof. Each of the four sides of every brick, which faces another brick in the roof, has two essentially parallel surfaces (A11, A12; A21, A22; A31, A32; A41, A42; B11, B12; ...; B41, B42; C11, C12; ...; C41, C42) which are inclined to a plane essentially parallel with the roof and are joined by a surface which is essentially parallel with the roof. Each of the bricks (A) directly supported by the supporting structure has at least two opposite sides having surfaces (for instance A11, A31; A12, A32) which are inclined downwards and away from each other. Each of the remaining bricks (B, C) has at least two opposite sides having surfaces (for instance B11, B31; B12, B32; C21, C41; C22, C42) which are upwardly inclined away from each other.

Description

[0001] The present invention relates to a refractory roof for a space which is intended to be subjected to very high temperatures, for example high-temperature furnaces. The invention also relates to a special refractory brick for building the refractory roof.

[0002] More specifically, the present invention relates to a refractory roof, which comprises refractory bricks arranged in parallel rows and having side surfaces substantially connecting with each other, and a superjacent supporting structure for directly supporting some of the bricks, which in turn support the remaining bricks.

[0003] Such refractory roofs are previously known in which each brick in every row or every second row has a groove in two opposite side surfaces or in one side surface for receiving one lateral flange of an I-beam, which is included in the superjacent supporting structure. The grooved side surfaces are substantially parallel to the web of the I-beam, which, when deflecting the roof perpendicularly to the longitudinal direction of the I-beams, results in the forming of gaps from the space under the roof up to the lower flanges of the I-beams. Although the lower side of these flanges is protected by insulating material, the strain on the lower flanges of the I-beams will have a detrimental effect on the life of the refractory roof.

[0004] Owing to the difficulty in manufacturing the refractory bricks included in the refractory roof with very great dimensional accuracy, undesirable gaps may arise also without deflection of the roof.

[0005] Refractory roofs are also known, in which the bricks included are interconnected by tongue-and-groove joints on all side surfaces. Also in this case, undesirable gaps may arise, reducing the life of the roof and, besides, the brick shape is very complicated, which results in difficulties in obtaining sufficient dimensional accuracy in the manufacture thereof.

[0006] The main object of the present invention therefore is to provide a refractory roof which has a longer life by eliminating the risk of gaps arising between the bricks, at the same time as the bricks are not of a too complicated shape and do not require great dimensional accuracy to fulfil their function.

[0007] A further object of the invention is to provide a refractory roof by means of refractory bricks in a small number of different shapes, said roof being possible to build optionally from the side, from above or from below.

[0008] According to the invention, these objects are achieved by the refractory roof of the type mentioned by way of introduction being characterised in that each brick is quadrilateral in planes which are essentially parallel with the roof, that each of the four sides of every brick, which faces another brick in the roof, has two essentially parallel surfaces which are inclined to a plane extending essentially in parallel with the roof, and are joined by a surface which is essentially parallel with the roof, that each of the bricks directly supported by the supporting structure has at least two opposite sides having surfaces which are inclined downwards and away from each other, and that each of the remaining bricks has at least two opposite sides having surfaces inclined upwards and away from each other.

[0009] By the fact that thus all interconnecting sides of any two refractory bricks in the roof have two essentially parallel surfaces inclined to the plane of the roof, which are mutually offset in the plane of the roof and joined by a surface which is essentially parallel with the plane of the roof, a refractory roof is obtained, in which the risk of through gaps in the roof is substantially completely eliminated.

[0010] In the preferred embodiment of the refractory roof according to the invention, only every second brick in every second row is directly supported by the superjacent supporting structure. Each brick directly supported by the supporting structure can have a lower portion in the form of a first truncated pyramid and an intermediate portion connecting with the lower portion and being in the form of a second truncated pyramid which has a smaller base area than the top area of the first truncated pyramid. The first truncated pyramid preferably is substantially centred relative to the second truncated pyramid.

[0011] Furthermore, each brick directly supported by the superjacent supporting structure suitably comprises an upper portion connecting with the intermediate portion and having means which permit the superjacent supporting structure to support the brick. These means may comprise, for instance, two lugs projecting in opposite directions from the upper portion in the plane of the roof, the superjacent supporting structure being able to engage with the lower sides of said lugs.

[0012] The bricks directly supported by the superjacent supporting structure constitute a first type of brick included in the refractory roof. A second type of brick included in the refractory roof may consist of the bricks between two neighbouring rows of directly supported bricks, the intermediate bricks each having essentially parallel surfaces on their two opposite sides extending transversely of the rows.

[0013] A third and last type of brick included in the refractory roof consists of every brick between two neighbouring, directly supported bricks in one row. This type of brick is designed to completely fill the space between surfaces of the lower portions and intermediate portions of these two directly supported bricks, said surfaces facing each other, and has the same cross-sectional shape as these directly supported bricks transversely of the longitudinal direction of the row.

[0014] The invention will now be described in more detail with reference to the accompanying drawings.

[0015] Fig. 1 is a cross-sectional view of a refractory roof according to prior-art technique.

[0016] Fig. 2 is a perspective view seen obliquely from above of an embodiment of a refractory roof according to the present invention, without the associated supporting structure.

[0017] Figs 3 and 4 are cross-sectional views along lines III-III and IV-IV in Fig. 2.

[0018] Fig. 5 is a perspective view of a first type of brick included in the refractory roof according to Figs 2-4.

[0019] Figs 6-8 are a perspective view, a front view and a side view of a second type of brick included in the refractory roof according to Figs 2-4.

[0020] Figs 9-11 are a perspective view, a front view and a side view of a third type of brick included in the refractory roof according to Figs 2-4.

[0021] Fig. 12 illustrates an alternative supporting structure according to the invention.

[0022] In the refractory roof according to prior-art technique shown in a cross-sectional view in Fig. 1, a plurality of parallel rows of substantially identical refractory bricks 1 are supported by means of a supporting structure with superjacent I-beams 2. More specifically, each brick 1 has grooves in opposite sides for receiving the lower flange of two neighbouring I-beams 2. To protect the I-beams against the high temperature in the space under the bricks 1, the grooves are filled with insulating material 3. Insulating material is usually also arranged on the upper side of the bricks 1 to protect the uppermost parts of the supporting structure, including an additional roof, if any.

[0023] As previously described, there is a considerable risk of gaps arising between two bricks 1 up to the lower side of the intermediate I-beam 2, thereby subjecting this to the high temperature in the space under the bricks 1, which of course implies that the life of the supporting structure and, thus, the refractory roof is shortened.

[0024] The embodiment of a refractory roof according to the invention as illustrated in Fig. 2 uses three types A, B and C of refractory bricks. These refractory bricks A-C are arranged in parallel rows, of which only three rows 4, 5 and 6 are shown. The bricks A constitute every second brick in every second row, for instances the rows 4 and 6. The bricks B are arranged in the same rows as the bricks A and each between two neighbouring bricks A. The bricks C form the remaining rows of bricks positioned between the rows of the bricks A. The bricks A-C are arranged in parallel rows also transversely of the rows 4-6.

[0025] As shown in Figs 3-11, each of the four sides of every brick A-C, which faces another brick in the roof, has two essentially parallel surfaces A11, A12; A21, A22; A31, A32; A41, A42; B11, B12; ...; B41, B42; C11, C12; ...; C41, C42 which are inclined to a plane essentially parallel with the roof and which are joined by a surface A13; A23; A33; A43; B13; ...; B43; C13; ...; C43, which is essentially parallel with the roof, i.e. a plane essentially parallel with the roof.

[0026] It will be appreciated that owing to this construction, it is hardly possible for through gaps to form, not even when deflecting the supporting structure. It is also obvious that the construction is relatively insensitive to dimensional variations of the individual bricks A-C.

[0027] The opposite sides of the bricks A have surfaces A11, A31; A12, A32; A21, A41; A22, A42 which are downwardly inclined away from each other. However, the construction could be such that only two opposite sides of the brick A have surfaces which are downwardly inclined away from each other.

[0028] In the embodiment shown, every brick A thus comprises a lower portion A7 in the form of a first truncated pyramid, and an intermediate portion A8 in the form of a second truncated pyramid of a smaller base area than the top area of the first truncated pyramid, said intermediate portion A8 connecting with the lower portion A7. As illustrated, the first truncated pyramid A7 is substantially centred relative to the second truncated pyramid A8. This results in the surfaces A13, A23, A33 and A43.

[0029] Each brick A further comprises an upper portion A9 connecting with the intermediate portion A8 and serving to support the brick A in the superjacent supporting structure, which in the case shown in Fig. 3 comprises box girders 50 which are in turn supported by an additional roof 51. The upper portion of the bricks A comprises two lugs A91, A93 which project from opposite sides of the upper portion A9 such that the upper part of the upper portion A9 is insertable into a box girder 50 to be supported by this.

[0030] As shown in Fig. 3, each brick B, between two neighbouring, directly supported bricks A in a row, for example row 4, completely fills the space between the surfaces A11, A31 and A12, A32, respectively, facing each other, of the lower portions 7 and the intermediate portions A8 of these two bricks A. As is evident from, inter alia, Fig. 4, the bricks B further have the same cross-sectional shape as the directly supported bricks A transversely of the longitudinal direction of the rows, for example rows 4, 6.

[0031] The bricks C between two neighbouring rows, for instance rows 4 and 6, of the directly supported bricks A each have essentially parallel surfaces C11, C12, C31, C32 on their two opposite sides transversely of the rows 4-6.

[0032] The above described embodiment of a refractory roof according to the present invention can be modified in several respects within the scope of the invention, as defined in the accompanying claims. For example, the supporting structure can be designed in some other manner than the one illustrated in Figs 3 and 4. An example of a different supporting structure thus is shown in Fig. 12, in which yokes 52 engaging with the lugs A91 and A93 are used as part of the supporting structure. As an alternative to the bricks C, bricks of essentially the same shape as the bricks B and bricks having a shape complementary thereto could be used.

Claims

1. A refractory roof, comprising refractory bricks (A, B, C) arranged in parallel rows (4-6), said bricks having side surfaces connecting with each other, and a superjacent supporting structure (50, 51; 52) for directly supporting some of the bricks, which in turn support the remaining bricks, characterised in
   that each brick (A, B, C) is quadrilateral in planes which are essentially parallel with the roof,
   that each of the four sides of every brick, facing another brick in the roof, has two essentially parallel surfaces (A11, A12; A21, A22; A31, A32; A41, A42; B11, B12; ...; B41, B42; C11, C12; ...; C41, C42) which are inclined to a plane essentially parallel with the roof and are joined by a surface (A13; A23; A33; A43; B13; ...; B43; C13; ...; C43) which is essentially parallel with the roof,
   that each of the bricks (A) directly supported by the supporting structure has at least two opposite sides with surfaces (for example A11, A31; A12, A32) which are inclined downwards and away from each other, and
   that each of the remaining bricks (B, C) has at least two opposite sides with surfaces (for instance B11, B31; B12, B32; C21, C41; C22, C42) which are inclined upwards and away from each other.

2. The refractory roof as claimed in claim 1, characterised in that every second brick (A) in every second row (for instance 4, 6) is directly supported by the supporting structure.

3. The refractory roof as claimed in claim 2, characterised in that each directly supported brick (A) comprises a lower portion (A7) in the form of a first truncated pyramid and an intermediate portion (A8) connecting with the lower portion and being in the form of a second truncated pyramid which has a smaller base area than the top area of the first truncated pyramid.

4. The refractory roof as claimed in claim 3, characterised in that the first truncated pyramid (A7) is substantially centred relative to the second truncated pyramid (A8).

5. The refractory roof as claimed in claim 3 or 4, characterised in that each directly supported brick (A) comprises an upper portion (A9) connecting with said intermediate portion (A8) and having means (A91, A93) which permit the superjacent supporting structure to support the brick.

6. The refractory roof as claimed in any one of claims 2-5, characterised in that the bricks (C) between two neighbouring rows (for instance 4, 6) of directly supported bricks (A) each have essentially parallel surfaces (C11, C12, C31, C32) on their two opposite sides extending transversely of said rows (4, 6).

7. The refractory roof as claimed in any one of claims 2-6, characterised in that each brick (B) between two neighbouring, directly supported bricks (A) in one row (for instance 4, 6) is designed to completely fill the space between surfaces (A11, A31; A12, A32), facing each other, of the lower portions (A7) and intermediate portions (A8) of these two bricks and has the same cross-sectional shape as the directly supported bricks transversely of the longitudinal direction of the row.

8. The refractory roof as claimed in any one of claims 2-7, characterised in that the remaining bricks (C) between two neighbouring rows (for instance 4, 6) of directly supported bricks (A) are designed to completely fill the space between the surfaces (A21, A41; A22, A42) facing each other, of said lower portions (A7) and said intermediate portions (A8) of the directly supported bricks of the two neighbouring rows.

9. A refractory brick for building a refractory roof according to claim 1, characterised by a lower portion (A7) in the form of a first truncated pyramid and an intermediate portion (A8) connecting with said lower portion and being in the form of a second truncated pyramid which has a smaller base area than the top area of the first truncated pyramid, and an upper portion (A9) connecting with said intermediate portion and having means (A91, A93) which permit the superjacent supporting structure to support the brick.

10. The refractory brick as claimed in claim 9, characterised in that the means (A91, A93) of said upper portion (A9) comprise two lugs extending in opposite directions and integrated with the upper portion.

Drawing