Shielding shoe for walking beam furnaces

Abstract

The subject of the present invention is a shielding shoe for covering openings in the bottom of a walking beam furnace, the shielding shoe having a semi-circular recess and can thereby be taken up by a vertical support of the walking beam furnace. The shielding shoe consists essentially of refractory cast concrete or refractory rammed concrete and, according to the invention, has a honeycomb-like structure below the shielding jacket. The present invention also relates to a walking beam furnace with such shielding shoes.

Claims

1. A shielding shoe (1a) for covering an opening in a bottom of a walking beam furnace, the shielding shoe having an upper side and a lower side, comprising: a shielding jacket (8a) having a semi-circular recess (9a) configured to be taken up by a vertical support (5a) of the walking beam furnace, wherein the shielding shoe (1a) is formed from refractory cast concrete or refractory rammed concrete, and the shielding shoe (1a) has a honeycomb-like structure (7a) below the shielding jacket (8a) toward the lower side.

2. The shielding shoe (1a) according to claim 1, wherein the shielding jacket (8a) has a constant thickness (X) above the honeycomb-like structure (7a).

3. The shielding shoe (1a) according to claim 2, wherein the honeycomb-like structure (7a) has a uniform wall thickness (Y).

4. The shielding shoe (1a) according to claim 2, wherein the shielding shoe (1a) has curved slots (10a) in an area of the recess (9a) configured to allow the shielding shoe (1a) to be suspended on holding clamps (2a) fastened to the vertical support (5a).

5. The shielding shoe (1a) according to claim 2, wherein the shielding shoe (1a) has at least one block hole (3a) on its upper side.

6. The shielding shoe (1a) according to claim 1, wherein the honeycomb-like structure (7a) has a uniform wall thickness (Y).

7. The shielding shoe (1a) according to claim 6, wherein the shielding shoe (1a) has curved slots (10a) in an area of the recess (9a) configured to allow the shielding shoe (1a) to be suspended on holding clamps (2a) fastened to the vertical support (5a).

8. The shielding shoe (1a) according to claim 1, wherein the shielding shoe (1a) has curved slots (10a) in an area of the recess (9a) configured to allow the shielding shoe (1a) to be suspended on holding clamps (2a) fastened to the vertical support (5a).

9. The shielding shoe (1a) according to claim 8, wherein the slots (10a) are C-shaped from a top view.

10. The shielding shoe (1a) according to claim 8, wherein the shielding shoe (1a) has at least one block hole (3a) on its upper side.

11. The shielding shoe (1a) according to claim 1, wherein the shielding shoe (1a) has at least one block hole (3a) on its upper side.

12. A shielding shoe (1a) for covering an opening in a bottom of a walking beam furnace, the shielding shoe having an upper side and a lower side, comprising: a shielding jacket (8a) having a semi-circular recess (9a) configured to be taken up by a vertical support (5a) of the walking beam furnace, wherein the shielding shoe (1a) is formed from refractory cast concrete or refractory rammed concrete, the shielding shoe (1a) has a honeycomb-like structure (7a) below the shielding jacket (8a) toward the lower side, the shielding jacket (8a) has a constant thickness (X) above the honeycomb-like structure (7a), the honeycomb-like structure (7a) has a uniform wall thickness (Y), the shielding shoe (1a) has curved slots (10a) in an area of the recess (9a) configured to allow the shielding shoe (1a) to be suspended on holding clamps (2a) fastened to the vertical support (5a), and the shielding shoe (1a) has at least one block hole (3a) on its upper side.

13. A walking beam furnace having at least one support (5a) projecting upward through an opening, comprising a pair of shielding shoes (1a), each shielding shoe (1a) of the pair of shielding shoes having an upper side and a lower side, and comprising: a shielding jacket (8a) having a semi-circular recess (9a) configured to be taken up by a vertical support (5a) of the walking beam furnace, wherein each shielding shoe (1a) of the pair of shielding shoes is formed from refractory cast concrete or refractory rammed concrete, each shielding shoe (1a) of the pair of shielding shoes has a honeycomb-like structure (7a) below the shielding jacket (8a) toward the lower side attached to the support (5a), and each shielding shoe (1a) of the pair of shielding shoes is attached to the support (5a).

14. The walking beam furnace according to claim 13, comprising curved holding clamps (2a) fastened to the support (5a) into which each shielding shoe (1a) of the pair of shielding shoes is suspended.

15. The walking beam furnace according to claim 14, comprising a supporting ring (6a) fastened to the support (5a) on which each shielding shoe (1a) of the pair of shielding shoes rests on.

16. The walking beam furnace according to claim 13, comprising a supporting ring (6a) fastened to the support (5a) on which each shielding shoe (1a) of the pair of shielding shoes rests on.

17. The walking beam furnace according to claim 16, wherein half of the supporting ring (6a) and a respective holding clamp (2a) are formed as a one-piece component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the state of the art and an embodiment of the invention is described on the basis of drawings. In these drawings:

(2) FIG. 1 is a schematic cross-section through two shielding shoes attached to a support according to the state of the art;

(3) FIG. 2 shows a top view of the shielding shoes in FIG. 1;

(4) FIG. 3 shows a schematic cross section through two of the disclosed shielding shoes; and

(5) FIG. 4 shows a top view of the two shielding shoes in FIG. 3.

DETAILED DESCRIPTION

(6) FIG. 1 and FIG. 2 each show two conventional shielding shoes 2 attached to a support 1. These shielding shoes 2 are each usually composed of: refractory cast concrete with the density of 2.5-3.0 kg/dm.sup.3; a sheet 3 adapted to the diameter of the support 1; slotted pins 4 (anchors); of the ceramic fibre mat 5.

(7) The ceramic fibre mat 5 is attached to the rolled sheet 3 with the anchors already welded on as slotted pins 4. Then the slotted pins 4 are spread apart. The entire unit forms a shielding shoe 2 with the refractory cast concrete cast in a mould.

(8) A halved cast plate 6 (also called a plate) is used for mounting and supporting the shielding shoe 2. The two parts (left and right) of the cast plate 6 are placed on the support 1 in a predetermined position, welded on and covered with a ceramic fibre mat 7.

(9) Two shielding shoes 2 are needed to completely cover the slot in the floor. During assembly, one shielding shoe 2 is placed on one half of the cast plate 6 and the other on the second half. Both shielding shoes 2 are welded to the support 1 with the rolled sheet 3.

(10) To change a shielding shoe 2, the welded-on sheets 3 must be detached from the support 1 and the sheets 3 of the new shielding shoes 2 must be welded on again at the same position.

(11) FIGS. 3 and 4 show an example of the disclosed shielding shoes 1a. The shielding shoes 1a have a semi-circular recess 9a to be received on the support 5a. Instead of the cast plate, two new holding clamps 2a made of highly heat-resistant stainless steel or cast stainless steel are welded once to the support 5a and covered with a ceramic fibre mat 4a towards the furnace chamber. In this example, the holding clamp 2a is c-shaped. In top view, this is a c-shaped component which is welded with its rear side to the support 5a.

(12) To mount or dismount the new shielding shoe 1a, it is pushed onto or removed from the new holding clamps 2a. For this purpose, two curved slots 10a are provided in the shielding shoe 1a in the area of its semi-circular recess 9a, in which the two legs of the holding clamp 2a can be received. Due to the curved shape of the slots 10a, the shielding shoe 1a is held securely and the risk of stress cracks is minimised. Furthermore, the shielding shoe 1a rests on a circular supporting ring 6a.

(13) The upper side of the shielding shoe 1a is formed by the shielding jacket 8a. The shielding jacket here has a uniform thickness X. Below the shielding jacket is the honeycomb-like structure 7a, which is also made of refractory cast concrete or refractory rammed concrete. This honeycomb structure is produced by pouring the concrete into a corresponding casting mould in which the future webs of the honeycombs are recessed. In this example, the honeycomb structure 7a has a uniform wall thickness Y.

(14) To facilitate assembly/disassembly, a block hole 3a is provided in the shielding shoe 1a. During assembly/disassembly, a block with an eyelet is screwed into the block hole 3a, into which the hook of a lifting tool can then be hooked. For operation, the block hole 3a can be sealed with a refractory compound.

(15) The new shielding shoe 1a is thermally pre-treated (up to 1,400 C. is possible). This enables permanent storage in a dry and frost-free place without any loss of quality.

(16) In this example, two identical shielding shoes 1a are attached to the support 5a. What they have in common here is an elliptical floor plan (see FIG. 4). Accordingly, two holding clamps 2a are attached to the support 5a. The shielding jackets 8a of the two shielding shoes 1a form an umbrella-like shape, so that falling scale can slip off the shielding jacket 8a. This prevents or minimises disturbing deposits on the shielding shoe 1a.

(17) The described embodiment has the following advantages: 1. Weight reduction of the shielding shoe 1a by at least 35%; 2. Easier assembly/disassembly due to the reduced dead weight and use of the new block for handling; 3. Only one-time welding work is required for the fastening the holding clamps 2a and the supporting ring 6a; and 4. Permanent storage time of the manufactured and thermally treated shielding shoe 1a.