FIREPROOF MOLDING BODY AND METHOD FOR PRODUCING THE SAME

Abstract

A fireproof molding body having a hot side and a cold side opposite said hot side, wherein the fireproof molding body includes a first material with ceramic hollow sphere structures, wherein an amount of hollow sphere structures decreases from the hot side to the cold side. A method for producing a fireproof molding body in which a first material with ceramic hollow sphere structures is introduced into a casting mold and a grading of the hollow sphere structures is subsequently performed.

Claims

1. A refractory molding comprising: a hot side and a cold side opposite from the hot side, and a first material comprising ceramic hollow sphere structures, wherein an amount of hollow sphere structures are decreasing from the hot side to the cold side.

2. The refractory molding as claimed in claim 1, wherein the refractory molding consists of a material with ceramic hollow sphere structures.

3. The refractory molding as claimed in claim 1, further comprising: in addition to the first material with ceramic hollow sphere structures, a second material with sintered structures, the first material and the second material differing in that a sintered raw material of one particle size in the second material is replaced in the first material by a raw material with hollow sphere structures of the same particle size and the same particle size distribution.

4. The refractory molding as claimed in claim 3, wherein the other raw materials of the first and second materials are the same.

5. The refractory molding as claimed in claim 1, wherein the hollow sphere structures are at least partially broken before casting to form the refractory molding.

6. The refractory molding as claimed in claim 1, wherein the hollow sphere structures comprise hollow corundum spheres.

7. The refractory molding as claimed in claim 3, wherein the sintered structures comprise sintered corundum.

8. The refractory molding as claimed in claim 7, wherein a proportion by weight of sintered corundum in the second material exceeds 30% by weight of solid constituents of the second material.

9. A method for producing a refractory molding, comprising: introducing a first material with ceramic hollow sphere structures into a casting mold, and subsequently performing a grading of the hollow sphere structures.

10. The method as claimed in claim 9, wherein the grading of the hollow sphere structures is performed by vibration.

11. The method as claimed in claim 9, wherein the refractory molding is a heat shield element with a hot side and a cold side opposite from the hot side, and wherein the first material is introduced in a region of the hot side.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is explained in more detail by way of example on the basis of the drawings, in which schematically and not to scale:

[0020] FIG. 1 shows a refractory molding according to the invention in a schematic representation,

[0021] FIG. 2 shows a casting mold for the production of the refractory molding according to the invention,

[0022] FIG. 3 shows a further casting mold for the production of the refractory molding according to the invention and

[0023] FIG. 4 shows a flow diagram for the inventive method for producing a refractory molding.

DETAILED DESCRIPTION OF INVENTION

[0024] FIG. 1 shows schematically by way of example a heat shield element for a gas turbine combustion chamber as an exemplary embodiment of a refractory molding 1 according to the invention. The heat shield element 1 represented in FIG. 1 has a hot side 2, which is intended to face the interior of a combustion chamber, and a cold side 3, which is opposite from the hot side 2 and is intended to face the supporting structure of the combustion chamber, and also four circumferential sides 7, which connect the hot side 2 to the cold side 3. In two of the circumferential sides 7 there are grooves 8, which allow the engagement of a holding clip holding the heat shield element 1 on the supporting structure. Other holding possibilities, with which the grooves 8 are not necessary, may of course also be used. For example, the cold side 3 of the heat shield element 1 may be screwed to the supporting structure.

[0025] FIG. 2 shows a casting mold 4 for the production of the refractory molding 1 according to the invention by the method according to the invention, in which a first material with ceramic hollow sphere structures is introduced into the casting mold 4 and a grading of the hollow sphere structures is subsequently performed. The introduction of the first material is in this case performed on the hot side 2 of the refractory molding 1.

[0026] In FIG. 3, the casting mold 4 is divided into two chambers 6 by a retractable blade 5 in such a way that different materials for the hot side 2 and the cold side 3 of the refractory molding 1 can be introduced (for example poured).

[0027] A method for producing the heat shield element represented in FIG. 1 is shown in a schematic flow diagram and described on the basis of FIG. 4. At the beginning of the method, a first material, which comprises hollow sphere structures, is provided (step 9).

[0028] Various molding processes come into consideration. According to the invention, a casting mold, which has an opening 14 on the later hot side of the refractory molding, this opening 14 facing upward during casting, is provided (step 10).

[0029] The first material is introduced into this opening 14 (step 11).

[0030] The grading in the first material is set by vibration (step 12).

[0031] Subsequently, the refractory molding 1 is sintered (at temperatures preferably above 1550 C.) (step 13).

[0032] Alternatively, a casting mold 4 may be provided and divided into two chambers 6 by a blade 5. Then, the first material with hollow sphere structures and the second material without hollow sphere structures are introduced separately into one each of the chambers 6. Finally, the blade 5 is retracted and after that the refractory molding 1 is sintered, as already described.