EP3757497A1 - Radiation shoe - Google Patents

Abstract

Radiation shoe (1) for attachment to a pipe (4) of a furnace, in particular to a water or steam cooling pipe in a lifting slot in the floor of a walking beam furnace, comprising a refractory shielding body (2) with a central opening (3) for the pipe (4) , a substantially flat underside (5) and a thickness decreasing towards the outside from the central opening (3), and with a steel-free formed and fired and / or sintered shielding body (2).

Description

FIELD OF THE INVENTION

The invention relates to a radiation shoe according to the preamble of claim 1.

TECHNOLOGICAL BACKGROUND

Radiation shoes of the generic type are used in walking beam furnaces in order to minimize heat losses in the furnace system. To do this, they shield the area of the lifting slots in the bottom of the furnace.

In the typical application, the temperature range of approx. 1300 ° C, approx. 90% of the heat is transferred by radiation. Unscreened slots in the furnace release part of the radiation and thus the thermal energy through the furnace base into the environment. Nevertheless, in only about 5% of the walking beam ovens, lifting slots are shielded by generic radiation shoes. The reason for this is the risk that the mostly massive shoe components fall off and bring the furnace mechanics to a standstill. This in turn causes a furnace downtime and thus a loss of production.

Radiation shoes known from the prior art consist of reinforced concrete components that are welded to the pipe system. A disadvantage of this embodiment is that the components cannot be fired because this would destroy the steel portion. This is what gives these components their ultimate strength in operation after the moisture and later the chemically bound water have been expelled. Since the heating is undefined during operation, these components tend to develop cracks, which later lead to the destruction of the components and, in the worst case, to the aforementioned standstill.

In order to counteract the falling off, it is known to arrange the components used on large-format plates made of heat-resistant cast materials, see Fig. 1 . Although these plates, like the components themselves, are welded to the cooled pipe system and thus experience a certain degree of re-cooling, they tend to scale during operation.

DISCLOSURE OF THE INVENTION

Based on this, the invention is based on the object of creating a radiation shoe according to the preamble of claim 1, which, while being simple and inexpensive to manufacture, has a longer service life, is easy to assemble and can be removed without destruction for maintenance purposes.

This object is achieved in accordance with the features of claim 1.

As a result, a radiation shoe for fastening to a pipe of a furnace, in particular to a water or steam cooling pipe in a lifting slot in the floor of a walking beam furnace, comprising a refractory shielding body with a central opening for the pipe, a substantially flat bottom and one from the central opening towards the outside decreasing thickness, created, which has a steel-free formed and fired shielding body.

According to the invention, the radiation shoe essentially consists of a ceramic body which can be shaped and fired without any steel content.

Components of the radiation shoe that are annealed or fired according to the invention do not develop any cracks during operation and are therefore mechanically stronger. The support plate required in the prior art is not necessary. A narrow, for example approx. 50mm wide, support ring that is welded to the pipe system is sufficient. Since this support ring is not nearly as exposed, it does not scale. The fastening mechanism used is also placed very close to the pipe system and does not scale. Furthermore, it offers sufficient degrees of freedom to parry any thermal expansion. The component is very easy to remove and, in the case of surrounding repairs, can be put back on again.

The shielding body is preferably designed in two parts and can therefore be easily mounted around a pipe. A ceramic fiber mat can be provided between the two parts which expediently has a support for a support ring on the pipe.

The radiation shoe preferably has a recess for a holding device that extends from the opening into the shielding body. The holding device can have, for example, a support ring fastened, in particular welded, to the pipe and / or one, two or more hooks fastened, in particular welded, to the pipe.

The recess advantageously has a section which is designed to be complementary to a pin-shaped holding element. A clamp can be inserted into this section, for example made of a heat-resistant steel of quality 1.4841 or the like. The clamp can be designed at its free end to be hooked into the hook.

The section provided for receiving the block preferably extends from the central opening for the pipe obliquely downward in the direction of the outer edge of the shielding body.

The recess can also have a section designed to be complementary to the support ring attached to the pipe. The ceramic fiber mat expediently extends between the support ring and the shielding body.

The invention also provides a walking beam furnace comprising a lifting slot and a cooling tube arranged therein, as well as the radiation shoe according to the invention, with a support ring and hooks being attached to the cooling tube, into which pin-shaped retaining elements are hooked that extend into the shielding body.

Further properties, features and embodiments can be found in the following description, the figures and the claims.

BRIEF DESCRIPTION OF THE FIGURES

• Fig. 1 illustrates a known radiation shoe mounted on a cooling pipe of a walking beam furnace.
• Fig. 2 (a) to (e) shows the radiation shoe according to the invention mounted on a cooling pipe of a walking beam furnace in different views.
• Fig. 3 is an exploded view of the radiation shoe according to the invention together with fastening elements and tube.
• Fig. 4 (a) to (f) shows part of the shielding body in different sectional views.

DETAILED DESCRIPTION OF EMBODIMENTS

The in Fig. 2 The radiation shoe 1 shown comprises a refractory, steel-free formed and fired and / or sintered shielding body 2 with a central opening 3 through which a pipe 4 such as a water or steam cooling pipe of a walking beam furnace extends, a substantially flat underside 5 and one of the central opening 3 towards the outside decreasing thickness.

The shielding body 2 is formed here from two parts 2 ', 2 "which enclose the tube 4. A ceramic fiber mat 6 or the like is provided between the two parts.

The shielding body 2 rests on the ceramic fiber mat 6 on a narrow support ring 7, which can be welded to the tube 4 or otherwise attached to it. Against tilting of the parts 2 ', 2 "of the shielding body 2 on the support ring 7, two hooks 8 are expediently attached to the tube 4, in which pin-shaped fastening elements, so-called clamps 9, engage, which in turn fit into pin-shaped recesses 10 of the The shielding body extend in. The parts 2 ', 2 "of the shielding body 2 are thus held free of tension along the tilting force vector by the clamp / hook device. The clamps 9 can have a suitable surface structure for this purpose, e.g. a corrugation or a thread 11 as shown.

The individual elements of the radiation shoe 1 together with the holding device and tube 4 are shown in FIG Fig. 3 detailed,

Fig. 4 (e) Illustrates the recess 12 for the holding device on part 2 'of the shielding body 2. An upper recess section 13 for the hooks 8, a middle recess section 14 for the tube 4, a lower recess section 15 for the support ring 7 and a recess section 16 for the clamp can be seen 9 provided.

REFERENCE LIST

1

Radiation shoe

2

Shielding body

2 ', 2 "

part

3

opening

4th

pipe

5

bottom

6th

Ceramic fiber mat

7th

Support ring

8th

hook

9

Cock

10

Recess

11

thread

12th

Recess

13

Recess section

14th

Recess section

15th

Recess section

16

Recess section

Claims (9)

Radiation shoe (1) for attachment to a pipe (4) of a furnace, in particular to a water or steam cooling pipe in a lifting slot in the floor of a walking beam furnace, comprising a refractory shielding body (2) with a central opening (3) for the pipe (4) , an essentially flat underside (5) and a thickness decreasing towards the outside from the central opening (3), characterized by a steel-free shaped and fired and / or sintered shielding body (2). Radiation shoe according to Claim 1, characterized in that the shielding body (2) is constructed in two parts. Radiation shoe according to Claim 2, characterized in that a ceramic fiber mat (6) is provided between the two parts (2 ', 2 ") of the shielding body (2). Radiation shoe according to Claim 3, characterized in that the ceramic fiber mat (6) has a support for a support ring (7) on the tube (4). Radiation shoe according to one of Claims 1 to 4, characterized in that a recess is provided for a holding device which extends from the opening (3) into the shielding body (2). Radiation shoe according to Claim 5, characterized in that the recess has a section (15) which is complementary to a pin-shaped holding element (9). Radiation shoe according to Claim 6, characterized in that the section (15) extends obliquely downward from the opening (3) in the direction of the outer edge of the shielding body (2). Radiation shoe according to one of Claims 5 to 7, characterized in that the recess has a section (15) designed to be complementary to a retaining ring. Walking beam furnace comprising a lifting slot and a cooling tube arranged therein, characterized by a radiation shoe (1) according to one of the preceding claims, a support ring (7) attached to the cooling tube and hooks (8) attached to the cooling tube, into which pin-shaped retaining elements (9) are hooked, which extend into the shielding body (2).

Images