Metallurgical furnace

1. A metallurgical furnace, comprising

a furnace body,

a trunnion ring, and

a pedestal structure,

wherein the furnace body is arranged for rotating movement in the trunnion ring about a rotation axis by means of a supporting arrangement between the trunnion ring and the furnace body for connecting the trunnion ring and the furnace body, wherein said supporting arrangement comprising a bearing arrangement between the trunnion ring and the furnace body for allowing for said rotating movement, and

wherein the trunnion ring is pivotably connected to the pedestal structure for tilting movement of the furnace body about a horizontal pivoting axis,

the supporting arrangement comprises a first connection frame means between the furnace body and the bearing arrangement, and a second connection frame means between the bearing arrangement and the trunnion ring, wherein the first connection frame means and the second connection frame means surround the furnace body,

the first connection frame means is connected to the furnace body and to the bearing arrangement,

the second connection frame means is connected to the bearing arrangement and to the trunnion ring, and

the second connection frame is connected to the trunnion ring by a first attachment ( 9 ) providing for movements between the second connection frame means and the trunnion ring.

2. The metallurgical furnace according to claim 1 , wherein the first connection frame means comprises a closed mantle which surrounds the furnace body and which is connected to the furnace body by a second attachment providing for movements between the bearing arrangement and the furnace body caused by thermal expansion of the furnace body.

3. The metallurgical furnace according to claim 1 , wherein

the bearing arrangement comprises a slewing bearing that surrounds the furnace body, and

the slewing bearing comprises a first annular bearing means secured to the first connection frame means and a second annular bearing means secured to the second connection frame means, and at least one set of radial thrust bearings interposed between the first annular bearing means and the second annular bearing means, and at least one set of axial thrust bearings interposed between the first annular bearing means and the second annular bearing means for bearing the load of the furnace body and for bearing the load of the furnace charge.

4. The metallurgical furnace according to claim 3 , wherein the first annular bearing means is provided with a first cooling system for transporting thermal energy from the first annular bearing means with a cooling fluid circulating in the first cooling system.

5. The metallurgical furnace according to claim 3 , wherein the second annular bearing means is provided with a second cooling system for transporting thermal energy from the second annular bearing means with a cooling fluid circulating in the second cooling system.

6. The metallurgical furnace according to claim 1 , wherein the first attachment comprises a flange means projecting from an inner surface of the trunnion ring for supporting the second connection frame means within the trunnion ring in the axial direction of the furnace body.

7. The metallurgical furnace according to claim 6 , wherein the flange means is divided into several flange sections so that the second connection frame means is unsupported within the trunnion ring between two flange sections in the axial direction of the furnace body.

8. The metallurgical furnace according to claim 7 , wherein flange means comprises two flange sections which are symmetrically arranged at an inner surface of the trunnion ring with respect to the pivoting axis so that the second connection frame means is unsupported within the trunnion ring between two flange sections in the axial direction of the furnace body at the pivoting axis.

9. The metallurgical furnace according to claim 6 , wherein fastening means for fastening the second connection frame means to the flange means of the trunnion ring is provided so as to permit movement between the second connection frame means and the trunnion ring in the radial direction of the furnace body, and so as to prevent movement between the second connection frame means and the trunnion ring in the axial direction of the furnace body.

10. The metallurgical furnace according to claim 9 , wherein the flange means is provided with first holes and the second connection frame means is provided with second holes co-operating with the first holes so that an external fastening device such as a bolt projects at least partly through at least one first hole in the flange means and at least partly through at least one second hole in the second connection frame means, whereby said external fastening device fastening the second connection frame means to the flange means so that axial movement between the second connection frame means and the flange means in the axial direction of the furnace body is prevented but so that radial movement in the radial direction of the furnace body between the second connection frame means and the flange means is possible.

11. The metallurgical furnace according to claim 1 , wherein

the trunnion ring comprises an inner surface facing an outer surface of the second connection frame means, and

there is a gap between the inner surface of the trunnion ring and the outer surface of the second connection frame means so as to allow thermal expansion of the second connection frame means in relation to the trunnion ring.

12. The metallurgical furnace according to claim 1 , wherein

the outer surface of the second connection frame means has an essentially circular configuration,

the inner surface of the trunnion ring has a corresponding essentially circular configuration,

the outer diameter of the second connection frame means is smaller than the inner diameter of the trunnion ring so that there is a gap between the inner surface of the trunnion ring and the outer surface of the second connection frame means so as to allow thermal expansion of the second connection frame means in relation of the trunnion ring.

13. The metallurgical furnace according to claim 1 , wherein the trunnion ring comprises an inner surface facing an outer surface of the second connection frame means, wherein at least one of the inner surface and the outer surface comprising at least one guide means projecting into the other of the inner surface and the outer surface for carrying load and preventing the trunnion ring and the second connection frame means from rotating with respect to each other.