|Title of Invention||
|Abstract||The invention relates to a casting plant, in particular for steel strip. It is necessa steel strip to be supported, in particular downst casting means, in order to reduce stresses deformation. A flexible supporting element, in hain comprising rollers, is provided to follow on the ca ting means, the length of which chain is designed to be adjusted suitable adjusting means.|
The invention relates to a strip-casting plant, in particular for casting metal strips, in particular of steel.
Steel strip cast on the casting plant preferably has a thickness of up to 10 mm.
A casting plant for casting, in particular, steel melts is described in DE 34 23 834 C2 . The liquid steel from a storage tank is placed via a nozzle on to an endless revolving cooled belt which is supported by rollers. The solidified strip is transported by transportation means to a downstream plant for further processing, in particular for rolling. The solidified strip is still relatively soft and should not be subjected to bending stresses, at least not immediately upon casting, i.e. for example after leaving the revolving belt of the casting machine. In addition, there are considerable differences in temperature between the interior of the strip and the surface of the strip.
It is an object of the invention to reduce thermal and mechanical stresses in the cast strip.
According to the invention there is provided a strip-casting plant comprising a melt-feeding means and at least one cooling
means for cooling the melt, and wherein a flexible guiding and supporting element is provided for the solidified strip.
Accordingly, the invention provides for a flexible supporting element to be arranged in an arrangement following on the casting plant. The flexible supporting element is, in particular, stretched between the casting plant and a following transportation means. The vertical forces arising as a result of gravity are taken up by the flexible supporting element. To this end, the length of the supporting and guiding element is adjustable. As the flexible element, it is possible, for example, to use stretched steel belts, which may, in particular, be supported on rollers which may be revolving rollers or which may be driven synchronously with the transportation means. If the supporting element is a revolving element, it is advantageously possible to reduce the tensile forces exerted on the strip. The drive is controlled for this purpose.
According to a preferred embodiment, the flexible supporting element is a link chain, in the manner of a bicycle chain, a plurality of chains being arranged side by side in the direction of the breadth of the strip, or said chains being intertwined such that they provide an adequately large bearing surface.
According to a further preferred embodiment, the flexible supporting element, i.e. in particular the chain, comprises
roller elements. It is possible for these roller elements to be designed to be rollers or spherical elements which revolve in the direction of transportation of the strip. It is also the main objective in these embodiments to take up the vertical forces and to ensure a transportation of the cast strip in the direction of transportation with the minimum of friction. The roller elements are preferably co-revolving and/or driven in regions in the longitudinal direction of the strip, in order to prevent tensile and compressive stresses in the supported region.
According to a further preferred embodiment, adjusting means for adjusting the tension of the flexible supporting element in its longitudinal direction are arranged on the flexible supporting element, i.e. in particular the supported belt or, preferably, the chain comprising roller elements. As a result hereof, it is possible to set the pendent curvature and, thus, the length of the sector supported by the flexible supporting element. As a result hereof, in addition to providing a support for the belt and reducing the stresses in the cast strip, it is possible, particularly advantageously, to permit compensating for different rotational speeds of the transportation means (transport rollers). The flexible supporting element thus also acts as a buffer for adjusting the tension of the strip. When the following conveying means has a higher speed than the preceding means, it is possible for the traction of the strip to be balanced out by reducing the length of the flexible supporting element, with a simultaneous
reduction in the speed of the following transport roller. Conversely, when the following transport roller is running at too low a speed, it is possible for the tension on the flexible supporting element to be reduced, thereby increasing the supported length and, simultaneously, increasing the speed of the following transport roller.
The supported length of the flexible supporting element is preferably altered by adjusting means, which are designed to be controllably set in conjunction with appropriate measuring and processing means according to the turning moment of the revolving roller on the casting plant.
It is possible to use tension rollers as the adjusting elements for an endless revolving belt or chain.
In a finite belt or chain, hydraulic tension cylinders are preferably arranged at the belt ends or at one belt end. It is, in particular, also possible to provide a combination of a revolving belt and a supporting chain.
The invention will be described in more detail with reference to an exemplified embodiment which is diagrammatically illustrated in the attached drawing.
The casting plant according to the invention comprises a casting means 1 which includes an endless revolving belt, a compensating section 2 and a following conveying means 3. The
cast continuous strip 4 is transported between the conveying means 3 and the roller 11 of the casting means 1. The flexible supporting element 5 is arranged in the compensating section 2 between the two conveying means 3, 11. As indicated, the flexible supporting element 5 is designed to be a chain with rollers. The chain 5 is stretched by means of supporting rollers 51 and chain adjusters 52. The pendent curvature of the chain 5 determines the length of the strip 4. When in the stretched state, the strip 4 is guided substantially in the broken-lined position in alignment with and between the conveying means 11 and 3. When the chain tension is reduced, the belt is suspended in the pendent curvature between the rollers 51.
In conjunction with measuring and control means, which are not illustrated, the tension of the chain 5 is controlled as a factor depending on the turning moment on the roller 12. The speed of the rollers of the conveying means 3 are preferably also controlled by the control means.
The arrangement of a flexible supporting element is advantageous in all instances where the cast continuous strip is to be supported in order to reduce vertical loads. Accordingly, it is possible for the flexible supporting element to be used advantageously, not only in strip-casting plants, but also in casting plants for other dimensions.
In a further preferred arrangement, the length of the
supporting element is changed such that a constant supporting force is exerted on the strip carried. To this end, the force acting on the chain is, for example, determined in relation to positipn. The supporting force to be set as a controlled variable is calculated from the difference relative to the force measured with the continuous casting, taking into consideration the forces of inertia.
In a further preferred arrangement, the chain or the belt is supported for rotation at one or more points, such that two or more loops are produced. As a result hereof, the degree of sagging is reduced, and it is possible for an encasing of the supporting element, for example for providing an inert gas atmosphere, to have a smaller volume.
WECLAIMS1. Strip-casting plant comprising a melt-feeding means
and at least one cooling means for cooling the melt, and
wherein a flexible guiding and supporting element is provided
for the solidified strip.
2. Strip-casting plant according to claim 1, in which
the length of the supporting element is adjustable.
3. Casting plant according to claim 1 or claim 2, in
which a chain is provided as the flexible supporting element.
4. Casting plant according to claim 1 or claim 2, in which roller elements are arranged in the flexible supporting element.
5. Casting plant according to claim 1 or claim 2, in which a belt is arranged as the supporting element.
6. Casting plant according to any one of claims 1 to 5,
in which the supporting element forms an endless loop.
7. Casting plant according to claim 6, in which the
supporting element is a revolving element.
8. Casting plant according to any one of claims 1 to 7,
in which at least one adjusting means is arranged on the
flexible supporting element for adjusting the tension in the longitudinal direction.
9. Casting plant according to claim 8, in which the adjusting means includes at least one tension roller.
10. Strip casting plant, substantially as hereinabove described and illustrated with reference to the accompanying drawing.
|Indian Patent Application Number||1186/MAS/1997|
|PG Journal Number||26/2007|
|Date of Filing||03-Jun-1997|
|Name of Patentee||M/S. PREUSSAG STAHL AG|
|Applicant Address||GERHARD-LUCAS-MEYER-STRASSE 3-5, D 31226 PEINE.|
|PCT International Classification Number||B22D11/06|
|PCT International Application Number||N/A|
|PCT International Filing date|