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(11) | EP 0 008 314 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
COOLED COMPONENTS FOR FURNACES KÜHLKOMPONENTEN FÜR ÖFEN COMPOSANTS REFROIDIS POUR FOURNEAUX |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0002] Amongst the cooled components used in blast furnaces are the coolers, such as stack and bosh coolers, which are built into the refractory lining of the furnace, and tuyeres. These components are normally castings of copper or copper alloy.
[0003] The noses of tuyeres and coolers inevitably become exposed to erosion by the burden of ore, coke, limestone, etc., in the blast furnace, the exposure becoming progressively greater as the furnace lining wears away.
[0004] The object of the present invention is to improve the resistance to abrasion during use of cooled components for furnaces.
[0005] It has been proposed (DE A-2 601 727) to provide the main cast metal body of components such as blast furnace tuyeres with a protective coating at the nose or blast exit end, said coating consisting of carbide particles bonded and/or fused into the tuyere surface, in order to protect the surface against damage.
[0006] It has also been proposed to protect a tuyere against wear by means of a cast-in plate-like toroidal insert (DE-C-148071 and US-A-1673053).
[0007] According to the present invention, there is introduced into the cast matel at the nose of the component a mesh element or an expanded metal element with greater abrasion resistance than the metal used for the main body of the component. Such protective element provides a continuous network of abrasion resistant material.
[0008] The material that may be used for the protective element include stainless steel meshes of varying thicknesses, and various compressed refractories capable of withstanding the thermal shock in a matrix of copper.
[0009] The materials concerned are introduced into the casting by locating them in position in the mould before casting is commenced.
[0010] A particularly suitable element is expanded metal from stainless steel or heat resistant steel. An expanded metal element has a certain amount of depth as well as length and breadth and the spaces between the steel strips can be varied to give the desired gap, filled with the cast copper or other material, thus providing the desired good heat conduction from the exterior of the element to the cooling medium.
[0011] Various forms of the invention will now be further described with reference to the accompanying drawings in which:
Fig. 1 is part of an expanded steel element which can be used for the purposes of the invention;
Fig. 2 is a side view of a blast furnace cooler according to the invention;
Fig. 3 is a section on a larger scale taken on the line III-III of Fig. 2; and
Fig. 4 is a section through a tuyere according to the invention.
[0012] Fig. 1 of the drawings shows part of an expanded stainless steel element, generally designated by the reference numeral 10. This has been made in the usual way by cutting and expanding a sheet of stainless steel to give a lattice of strips 12 adjoined by flat nodes 14 which, as they are twisted out of the plane of the paper as seen in Fig. 1, give some depth to the structure as well as length and breadth. Spaces 16 between the strips 12 and nodes 14 will be filled by the cast metal in the finished article and will allow good conduction of heat to the surface of the cast component.
[0013] The expanded sheet 10 can be cut to size and bent round very easily to form a curved or cylindrical shape.
[0014] Suitable gauge for the stainless steel sheet from which the element 10 is made is 20 gauge (0.91 mm), and the stainless steel may be, for example, according to BS1449 EN58B.
[0015] Figs. 2 and 3 show, on a smaller scale than that used in Fig. 1, a cooler, such as a bosh cooler, for a blast furnace. The cooler shown has a main cooling compartment 18 with inlet and outlet apertures 20 and 22, the nose end 24 of the cooler being cooled by means of a cast-in water pipe 26 having separate inlet and outlet 28 and 30.
[0016] The characterising feature of the cooler is the expanded stainless steel element 10 which is included in the casting by locating it in position in the casting mould and casting the copper of the cooler round it. As shown in Fig. 2 it extends at length across the whole width of the nose of the cooler just underneath the surface and has been bent to go round the cast-in pipe 26 as shown in Fig. 3.
[0017] Fig. 4 shows a tuyere of the sort having a main cooling chamber 30 surrounding an air- passage 32. The cooling chamber 30 has inlet and outlet apertures 46. The nose 34 of the tuyere is cooled by a separate cooling pipe 36 having an inlet pipe 38 leading thereto and a similar outlet pipe not seen in the section of Fig. 4.
[0018] The nose is reinforced with two rings of expanded metal, an inner ring 40 which is inside the nose cooling pipe 36 and an outer ring 42 which surrounds the said pipe. Additionally hard metal particles 44 are embedded in the copper of the tuyere forwardly of the cooling pipe 36.
1. A cooled cast component for a furnace having a nose which, when the component is
in position, is directed towards the interior of the furnace, characterised in that
there is introduced into the cast metal at the nose of the component a mesh element
or an expanded metal element with greater abrasion resistance than the metal used
for the main body of the component.
2. A component as claimed in claim 1 being a cooler for the wall of a blast furnace.
3. A component as claimed in claim 1 being a tuyere.
4. A component as claimed in any one of the preceding claims wherein the said mesh
or expanded metal element comprises a stainless steel element.
5. A component as claimed in any one of the claims 1 to 3 wherein the said mesh or
expanded metal element comprises a heat resistant steel element.
6. A component as claimed in any one of the preceding claims wherein there are also
introduced into the cast metal at the nose of the component particles of another material
having a greater abrasion resistance than the metal used for the main body of the
component.
1. Gekühltes Gußbauteil für einen Ofen, mit einer bei in Stellung gebrachtem Bauteil
zum Inneren des Ofens gerichteten Nase, dadurch gekennzeichnet, daß in das Gußmetall
an der Nase des Bauteils ein eine größere Abriebfestigkeit als das für den Hauptkörper
des Bauteils verwendete Metall aufweisendes Gitterelement oder aufgestrecktes Metallelement
eingebettet ist.
2. Bauteil nach Anspruch 1, dad einen Kühler für die Wand eines Hochofens bildet.
3. Bauteil nach Anspruch 1, das eine Windform bildet.
4. Bauteil nach einem der vorstehenden Ansprüche, bei dem das Material ein Element
aus rostfreiem Stahl beinhaltet.
5. Bauteil nach einem der Ansprüche 1 bis 3, bei dem das Material ein hitzebeständiges
Stahlelement beinhaltet.
6. Bauteil nach einem der vorstehenden Ansprüche, bei dem in das Gußmetall an der
Nase des Bauteils auch Teilchen eines eine größere Abriebfestigkeit als das für den
Hauptkörper des Bauteils verwendete Metall aufweisenden anderen Materials eingebettet
sind.
1. Composant coulé et refroidi pour un four ayant un nez qui, quand le composant est
en position, est dirigé vers l'intérieur du four, caractérisé en ce qu'on introduit,
dans le métal coulé, au nez du composant, un élément en maille ou un élément en métal
déployé ayant une plus forte résistance à l'abrasion que le métal utilisé pour le
corps principal du composant.
2. Composant selon la revendication 1, qui est un refroidisseur pour la paroi d'un
haut fourneau.
3. Composant selon la revendication 1, qui est une tuyère.
4. Composant selon l'une quelconque des revendications précédentes, du type où le
matériau comprend un élément en acier inoxydable.
5. Composant selon l'une quelconque des revendications 1 à 3, du type où ledit matériau
comprend un élément en acier résistant à la chaleur.
6. Composant selon l'une quelconque des revendications précédentes du type où est
également introduit dans le métal coulé, au nez du composant, des particules d'un
autre matériau ayant une plus forte résistance à l'abrasion que le métal utilisé pour
le corps principal du composant.