Uncooled furnace roll and method for producing an uncooled furnace roll

Abstract

The invention relates to an uncooled furnace roll (1) for transporting continuously cast material from a continuous casting facility, and to a method for the production of such a furnace roll. The furnace roll (1) comprises a cylindrical roll body (2), conical end pieces (6) being attached to the end faces (8) of the roll body. Inside the furnace roll (1) a hollow space (4) is provided in the region of the roll body (2) and/or in the region of at least one conical end piece, said hollow space being sealed off from the atmosphere (A) and being placed under vacuum.

Claims

1. An uncooled furnace roll (1) for transporting continuously cast material from (or in) a continuous casting facility comprised of a cylindrical roll body (2), and conical end pieces (6) which are attached to the respective end faces (8) of the roll body (2), characterized in that inside the furnace roll (1) a hollow space (4) is provided in the region of the roll body (2) and/or in the region of at least one conical end piece (6), said hollow space being sealed off from the atmosphere (A) and being under vacuum, so that vacuum means of thermal insulation are provided, at least for the roll body (2) and/or the conical end piece (6), and in that a connecting valve (12) is disposed in a wall (16) of the roll body (2) or of a conical end piece (6), which valve is in fluid communication with the hollow space (4) of the furnace roll, wherein the hollow space (4) of the furnace roll can be placed under vacuum via the connecting valve (12); wherein the connecting valve (12) is in the form of a check valve which shuts off the hollow space (4) with respect to the atmosphere (A) when the hollow space (4) is placed completely under vacuum.

2. The furnace roll (1) according to claim 1, characterized in that the cylindrical roll body (2) is entirely hollow, so that the hollow space (4) of the furnace roll extends at least along the entire longitudinal axis (2L) of the roll body (2), preferably such that the cylindrical roll body (2) is in the form of a cylindrical sleeve with a corresponding hollow space (4).

3. The furnace roll (1) according to claim 2, characterized in that at least one conical end piece (6) is in the form of a cap element, so that the hollow space (4) of the roll body (2), placed under vacuum, extends into the conical end piece (6) when said end piece (6) is attached to the end face (8) of the roll body (2).

4. A method for producing an uncooled furnace roll (1), characterized by the following steps: preparing a cylindrical roll body (2); preparing at least one conical end piece (6); and attaching a conical end piece (6) to an end face (8) of the roll body (2), such that thereby a hollow space (4) which is formed inside the furnace roll (1) in the region of the roll body (2) and/or in the region of the conical end piece (6) is closed off so as to be sealed against the atmosphere (A), wherewith the hollow space (4) is placed under vacuum; attaching the conical end piece (6) to an end face (8) of the roll body (2) in a vacuum chamber (14) by means of electron beam welding (EB welding).

5. The method according to claim 4, characterized in that a conical end piece (6) is attached to one of the two end faces (8) of the cylindrical roll body (2) before a second conical end piece (6) is attached to the still open opposite end face (8) of the roll body (2), in a vacuum chamber (14).

6. The method according to claim 4, characterized in that a respective conical end piece (6) is attached to the roll body (2) at both of its end faces (8), in the vacuum chamber (14).

7. A method for producing an uncooled furnace roll (1), characterized by the following steps: preparing a cylindrical roll body (2); preparing at least one conical end piece (6); and attaching the conical end piece (6) to an end face (8) of the roll body (2), such that thereby a hollow space (4) which is formed inside the furnace roll (1) in the region of the roll body (2) and/or in the region of the conical end piece (6) is closed off so as to be sealed against the atmosphere (A), wherewith the hollow space (4) is placed under vacuum; providing a connecting valve (12) which is in fluid communication with the hollow space (4) of the furnace roll and is disposed in a wall (16) of the roll body (2) or of the conical end piece (6), wherein after the conical end piece (6) is attached to the roll body (2), which serves to close off the hollow space (4), a vacuum is applied to the connecting valve (12), whereby the hollow space (4) is placed completely under vacuum; and wherein the connecting valve (12) is in the form of a check valve, which closes off the hollow space (4) with respect to the atmosphere (A) when the hollow space (4) has been placed completely under vacuum.

8. The method according to claim 7, characterized in that the connecting valve (12), with its opening (18), is recessed (countersunk) in an external surface (20) of the roll body (2) or of the end piece (6).

Description

BRIEF DESCRIPTION OF THE DRAWINGS:

(1) The invention is illustrated schematically in the accompanying drawings, and will be described in more detail hereinbelow, with reference to preferred embodiments.

(2) FIG. 1 is a simplified longitudinal cross-section of an inventive furnace roll according to a first embodiment;

(3) FIG. 2 is a perspective view of the furnace roll according to FIG. 1;

(4) FIG. 3 is a simplified longitudinal cross-section of an inventive furnace roll according to a second embodiment;

(5) FIG. 4 is a greatly simplified schematic drawing of a vacuum chamber with which (in which) the inventive method of producing a furnace roll according to FIG. 1 can be carried out; and

(6) FIG. 5 is a longitudinal cross-section of a wall of a furnace roll according to yet another embodiment;

(7) FIG. 6 is a longitudinal cross-section of an end face a customary uncooled furnace roll; and

(8) FIG. 7 is a longitudinal cross-section of an end face of another embodiment of a customary uncooled furnace roll.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) FIG. 1 illustrates an inventive furnace roll 1 (not necessarily with correct dimensions and dimensional relationships), in a simplified longitudinal cross-section. The furnace roll 1 is comprised of a roll body 2 in the form of a cylindrical hollow body. The roll body 2 surrounds a hollow space 4. Conical end pieces 6 are attached to the end faces 8 of the roll body 2, thereby separating the hollow space 4 from the atmosphere A.

(10) Given that the roll body 2 is in the form of a cylindrical hollow body, the hollow space 4 of the furnace roll 1 extends at least along the entire longitudinal axis 2L of the roll body 2. As illustrated in FIG. 1, the two conical end pieces 6 are in the form of cap elements. Accordingly, when the end pieces 6 are attached to the respective end faces 8 of the roll body 2, the hollow space 4 extends in the furnace roll 1 into the end pieces 6.

(11) The furnace roll according to FIG. 1 is illustrated in FIG. 2 in a perspective view. Journals 10 are affixed to the outer parts of the conical end pieces 6, which journals are rotatably mounted in bearings or the like (not shown). This arrangement with the journals 10 enables the furnace roll 1 to be driven rotationally around its longitudinal axis.

(12) In the embodiment according to FIG. 1, the hollow space of the furnace roll 1 is sealed with respect to the atmosphere A, and is placed under vacuum. Due to the fact that no air is present inside the hollow space 4, thermal insulation in the form of a vacuum is provided for the furnace roll 1 along its longitudinal axis, i.e. in the region of the roll body 2 and the two conical end pieces 6.

(13) FIG. 3 illustrates a simplified longitudinal cross-section of a furnace roll 1 (not necessarily with correct dimensions and dimensional relationships), according to a second embodiment of the invention. In contrast to the embodiment according to FIG. 1, the roll body 2 in the embodiment according to FIG. 3 is in the form of a solid cylinder, which has two conical end pieces 6 in the form of cap elements attached to its end faces 8. A hollow space 4 placed under vacuum is present in the embodiment according to FIG. 3 only in the conical end pieces 6, so that the vacuum insulation is effective at least for the conical end pieces 6. The roll body 2 in the embodiment according to FIG. 3 may comprise a cylindrical hollow body instead of a solid cylinder, but wherein the hollow space in the hollow body is not in communication with the hollow spaces 4 in the conical end pieces 6. With this arrangement, the wall of the roll body 2 may have an opening in it for air circulation with the atmosphere A, to adjust for volume changes in the air due to temperature fluctuations affecting the furnace roll 1 during operation of a tunnel furnace. In addition, thermal insulation material, e.g. fireproof material, may be provided in the hollow space of the roll body.

(14) In the following a method of producing the furnace roll 1 according to the present invention, with generation of a vacuum in the hollow space 4 of the furnace roll 1, is described; this is with reference to FIGS. 4 and 5. In other words, the inventive method will be described, with reference to FIGS. 4 and 5.

(15) FIG. 4 illustrates generally a greatly simplified representation of a vacuum chamber 14 in which vacuum welding processes can be performed.

(16) To fabricate an inventive furnace roll 1, its individual components, i.e. the roll body 2 and the two conical end pieces 6, can be brought into the vacuum chamber 14. The two conical end pieces 6 are then welded to the end faces 8 of the roll body 2. The arrows in FIG. 4 indicate the application of the two conical end pieces 6 against the end faces 8 of the roll body 2. The means of fastening the conical end pieces 6 to the end faces 8 of the roll body 2 may comprise electron beam welding (EB welding).

(17) The fabrication of a furnace roll 1 by means of welding its components together in a vacuum chamber 14 may apply for the embodiment according to FIG. 3 as well as to the embodiment according to FIG. 1. In each instance, due to the fabrication process being performed in vacuum, it is automatically provided that, following the attachment of the two conical end pieces 6 to the end faces 8 of the roll body 2, the hollow space 4 thereby generated and sealed against the surroundings is also under vacuum, which vacuum persists after the completion of the welding work and after the furnace roll 1 is removed from the vacuum chamber 14. In this connection, it is no longer necessary to provide air flow (air removal) openings in the wall of the roll body 2 or of a conical end piece 6.

(18) The journals 10 can be welded onto the respective conical end pieces 6 in the vacuum chamber 14.

(19) FIG. 5 illustrates a connecting valve 12 provided in a wall 16 of the roll body 2 or of a conical end piece 6. The connecting valve 12 is in fluid communication with the hollow space 4 of the furnace roll 1. A vacuum pump or the like can be connected to the connecting valve 12 through a connecting line (not shown), to produce a complete vacuum in the hollow space 4 of the furnace roll 1.

(20) The connecting valve 12 is preferably in the form of a check valve. In any event, the connecting valve 12 is configured such that, after a vacuum is produced in the hollow space 4, the hollow space will be sealed against the surroundings by the connecting valve 12, such that the vacuum in the hollow space will be maintained.

(21) A somewhat recessed opening 18 is provided for the connecting valve 12 in an outer surface 20 of the roll body 2. Thus, the opening 18 does not project radially beyond the outer circumferential surface 20, as a result of which rolled stock being transported via the roll body 2 does not come into contact with the opening 18.

(22) Alternatively to use of a vacuum chamber 14 (FIG. 4), a connecting valve 12 as described above in connection with FIG. 5 can be employed to fabricate a furnace roll 1 in a normal atmosphere. Then, after the two conical end pieces 6 have been welded to the end faces 8 of the roll body 2, the connecting valve 12 may be utilized for producing a vacuum in the hollow space 4 formed in the furnace roll 1, wherewith, after a complete vacuum has been established in the hollow space 4, the connecting valve 12 may be utilized to seal it against the atmosphere.

LIST OF REFERENCE NUMERALS

(23) 1 Furnace roll. 2 Roll body. 2L Longitudinal axis of the roll body. 4 Hollow space. 6 End piece. 8 End face of the roll body. 10 Journal. 12 Connecting valve. 14 Vacuum chamber. 16 Wall of the roll body 2 or of a conical end piece 6. 18 Opening for the connecting valve. 20 Outer circumferential surface. A Atmosphere.