GB1561891A

GB1561891A - Pre-fabricated concrete element for industrial furnaces

Info

Publication number: GB1561891A
Application number: GB4114776A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1975-10-17
Filing date: 1976-10-04
Publication date: 1980-03-05
Also published as: JPS5250309A; CH610397A5; DE2646960A1; IT1043445B; PT65686B; PT65686A; FR2328172A1; SU673199A3; BR7606941A; FR2328172B1; BR7606954A; ES451773A1; BE846648A

Abstract

With said element, used in particular for the construction of the walls of tunnel furnaces for the firing of bricks, the necessity is avoided of using materials which at the same time have characteristics of thermal resistance and mechanical strength. To this end, the prefabricated element, which is of parallelepipedal shape, comprises at least one cavity (2) adjacent to one wall and a series of three cavities (2') parallel to the cavity (2) and staggered in relation to the latter in such a manner that any passage at right angles to one wall encounters at least one of said cavities. Provided alternately on the edges of the element are projections (3) and recesses (3') which are capable of interacting to form a joint. <IMAGE>

Description

(54) PRE-FABRICATED CONCRETE ELEMENT FOR INDUSTRIAL FURNACES (71) I, ALDO ROLLA, an Italian citizen, of Via S. Andrea 7, Monza, Milano, Italy, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to prefabricated concrete elements for industrial furnaces, in particular for building walls of tunnel-type furnaces for baking tiles.

It is known that building a conventional tunnel-type furnace with an arch-shaped vault is an extremely long and difficult operation, in particular as far as the erection of the walls is concerned. To form the walls a proper distribution of the various materials employed is required, according to their characteristics, both regarding mechanical strength, and regarding the heat transmission. In erecting such walls, thermally-insulating materials or refractory materials with some compressive strength will have to be used. This problem also arises with the tunnel-type furnaces having self-supporting flat vaults such as the furnace disclosed in British Patent Specification No. 1,502,499.

According to the present invention there is provided a pre-fabricated concrete element for industrial baking furnaces, which element is parallelepiped in shape and is provided with at least two rows of parallel and mutually staggered cavities whereby any path perpendicular to a furnace wall formed by such pre-fabricated elements meets at least one of said cavities, the element being made of concrete which is both refractory and thermally-insulating.

The cavities may be filled with thermallyinsulating materials placed therein in bulk.

The amount of thermally-insulating material within the cavities may vary along the length of the furnace wall as a function of the temperature at the inner side of the wall itself.

Preferably, at least two pairs of edges placed at opposite faces of the parallel piped are formed respectively with a projection and a groove adapted to co-operate in a fitting relationship.

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows a perspective view of a prefabricated concrete element according to the invention; and Figure 2 shows a perspective view of a fragment of a wall, built by means of vertically disposed concrete elements according to Figure 1.

With reference to the drawings, a prefabricated concrete element according to the present invention comprises a substantially parallelepiped-shaped block 1 provided with two rows of parallel cavities 2, 2' in a staggered relationship, so as to reduce the escape of heat along the propagation direction, i.e. normal to the furnace wall. In fact, as it is shown by the example of wall represented in Figure 2, in which the prefabricated elements 1 are placed one on another so that the cavities 2 and 2' are upright, the preferred path of the thermal flux lines, indicated by arrow F, if the side A is the inner one at a higher temperature and the side B the outer, can never be perpendicular to the wall.In practice, any path normal to the furnace wall along which the heat to be transmitted, would always meet at least one row of cavities whereby it would have to deviate and would be obstructed even if the cavities are only filled with air, and not with thermally-insulating material. The degree of insulation would, however, be better if the cavities are filled with appropriate thermally-insulating materials.

When employing the pre-fabricated concrete elements according to the invention, the thickness of a wall may be formed by only one such element, if in said cavities 2, 2' appropriate thermally-insulating materials are introduced in bulk, such as ceramic fibres, rock wool or inert materials such as vermiculite, pearlite or expanded clay so as to keep constant the loss of heat when the temperature at the inner face of the furnace varies, by simply varying the amount of the materials in the cavities.

As shown by the figures, the two rows of cavities 2, 2' may be of different width and in particular it is preferable, but not nieces sary, that the larger cavity should be closer to the hot side of the wall, even if generally speaking the size of the cavities depends upon the filling materials employed, i.e.

their thermal characteristics and their density.

As shown in the figures, four edges of the element 1 have alternately a projection 3 and a groove 3' of corresponding crosssection, which form respectively the male and female elements of joints adapted to interconnect the pre-fabricated elements for building the walls, with the cavities 2, 2' placed either vertically or horizontally.

As previously stated, since the inner wall of the furnace (side A) is subjected to different temperatures from the inlet to the outlet of the furnace, with a maximum usually at the central zone of the furnace itself, pre-fabricated concrete elements of the same kind could however be employed by varying the amount of the thermallyinsulating materials within the cavities or their nature. On the other hand, elements 1 could otherwise be used. which are made of a given concrete for the end zones and another concrete having better thermal characteristics for the central zone of the furnace. For this purpose, insulating-re- fractory concrete of various compositions may be employed.

It is finally to be appreciated that when adopting a building method such as that disclosed in British Patent Specification No.

1,528,522, the pre-fabricated concrete elements according to the invention could be made of the most appropriate concrete from the thermal point of view without considering mechanical strength, as the function of the elements is only as a filler or a curtain wall, while the load of the vault is supported and transmitted to the ground by suitable uprights, as in dwelling buildings.

WHAT I CLAIM IS: 1. A pre-fabricated concrete element for industrial baking furnaces, which element is parallelepiped in shape and is provided with at least two rows of parallel and mutually staggered cavities whereby any path perpendicular to a furnace wall formed by such pre-fabricated elements meets at least one of said cavities, the element being made of concrete which is both refractory and thermally insulating.

2. A concrete element as claimed in claim 1, wherein the cavities are filled with thermally-insulating materials placed therein in bulk.

3. A concrete element as claimed in claim 2, wherein the amount of said thermally-insulating materials within said cavities varies along the furnace wall length as a function of the temperature at the inner side of the wall itself.

4. A concrete element as claimed in any preceding claim, wherein at least two pairs of edges placed at opposite faces of the parallelepiped are formed respectived with a projection and a groove adapted to cooperate in a fitting relationship.

5. A pre-fabricated concrete element for industrial baking furnaces substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the temperature at the inner face of the furnace varies, by simply varying the amount of the materials in the cavities. As shown by the figures, the two rows of cavities 2, 2' may be of different width and in particular it is preferable, but not nieces sary, that the larger cavity should be closer to the hot side of the wall, even if generally speaking the size of the cavities depends upon the filling materials employed, i.e. their thermal characteristics and their density. As shown in the figures, four edges of the element 1 have alternately a projection 3 and a groove 3' of corresponding crosssection, which form respectively the male and female elements of joints adapted to interconnect the pre-fabricated elements for building the walls, with the cavities 2, 2' placed either vertically or horizontally. As previously stated, since the inner wall of the furnace (side A) is subjected to different temperatures from the inlet to the outlet of the furnace, with a maximum usually at the central zone of the furnace itself, pre-fabricated concrete elements of the same kind could however be employed by varying the amount of the thermallyinsulating materials within the cavities or their nature. On the other hand, elements 1 could otherwise be used. which are made of a given concrete for the end zones and another concrete having better thermal characteristics for the central zone of the furnace. For this purpose, insulating-re- fractory concrete of various compositions may be employed. It is finally to be appreciated that when adopting a building method such as that disclosed in British Patent Specification No. 1,528,522, the pre-fabricated concrete elements according to the invention could be made of the most appropriate concrete from the thermal point of view without considering mechanical strength, as the function of the elements is only as a filler or a curtain wall, while the load of the vault is supported and transmitted to the ground by suitable uprights, as in dwelling buildings. WHAT I CLAIM IS:

1. A pre-fabricated concrete element for industrial baking furnaces, which element is parallelepiped in shape and is provided with at least two rows of parallel and mutually staggered cavities whereby any path perpendicular to a furnace wall formed by such pre-fabricated elements meets at least one of said cavities, the element being made of concrete which is both refractory and thermally insulating.