US20080264133A1

US20080264133A1 - Installation for Treating Continuously Cast Bars or Continuously Cast Billets

Info

Publication number: US20080264133A1
Application number: US11/587,071
Authority: US
Inventors: Christoph Keller; Yildirim Karamahmut
Original assignee: Individual
Current assignee: SMS Group GmbH
Priority date: 2004-04-22
Filing date: 2005-04-22
Publication date: 2008-10-30
Also published as: WO2005102558A2; DE102004020206A1; WO2005102558A3; EP1740330A2

Abstract

The invention relates to an installation for treating continuously cast bars (1) or continuously cast billets (2), which can be heated inside a furnace (7) to a deformation temperature before shearing off to form slugs (6) and the subsequent pressing inside a press (4). To this end, a number of shaft elements (8) for axially transporting continuously cast bars (1) or continuously cast billets (2) extend through the furnace (7). These shaft elements (8) are arranged in a fixed manner and mounted outside the furnace (7).

Description

The present invention relates to an installation for treating continuously cast bars or continuously cast billets that may be heated in a furnace to a deformation temperature before shearing to form slugs and subsequent pressing in a press.
In conventional installations for treating continuously cast bars or continuously cast billets, these are usually fed through a furnace by a chain conveyor.
A disadvantage with this is that the seats in the chain conveyor are at different temperatures and thus prevent homogeneous heating of the continuously cast billet.
Consequently, such chain conveyors must be transported through the furnace, which is undesired.
Other installations for treating continuously cast bars or continuously cast billets merely have roller elements mounted inside the furnace or inside a combustion chamber, the heated continuously cast billet having to be ejected by means of auxiliary devices.
In addition, for conventional installations for heating continuously cast bars or continuously cast billets that are heated to a deformation temperature in a furnace in preparation for a pressing procedure, the bars or billets are fed through the furnace by means of a conveyor and are heated by a plurality of gas burners or the like. This frequently results in uneven heating of the surfaces of the continuously cast bars or continuously cast billets, which in particular in the outer shell region may lead to undesired and problematic grain boundary fusion. Furthermore, for heating a continuously cast bar or continuously cast billet to a deformation temperature the energy requirements for conventional installations are extremely high.
The object of the present invention, therefore, is to provide an installation of the above-described type that eliminates the stated disadvantages and ensures homogeneous, uniform heating of continuously cast bars and continuously cast billets in a simple and economical manner. A further object is to enable homogeneous heating of the continuously cast bar or continuously cast billet. A further object is to significantly increase the efficiency of such an installation while keeping the energy consumption, in particular the gas consumption, low. A further object is to avoid grain boundary fusion.
This object is achieved by the features of the characterizing parts of claims 1, 5, 10, and 15.
In the present invention it has proven to be particularly advantageous to extend the shafts that are used for holding the continuously cast bars and continuously cast billets, radially from the furnace, in particular from the combustion chamber, and to externally and stationarily support and drive the shafts. In this manner a plurality of shafts may be positioned at a spacing from one another in the longitudinal direction of the furnace.
All the shafts preferably are driven to displace or move the continuously cast bars or continuously cast billets back and forth in the furnace.
This system permits a completely circumferential array of gas burners in the furnace or in the combustion chamber, so that the continuously cast bar or continuously cast billet can be heated to the deformation temperature essentially on all sides, i.e. all around, in a circumferential manner. Radially circumferential arrays of gas burners are provided that are repeated over the entire length as a second, third, or fourth array.
Thus, for example, a second array of the radially circumferential gas burners may be radially offset with respect to the first array, so that, for example, alternating spacings result between the gas burners of a first array and the second array. This procedure may be repeated. Homogenization of the heating process is likewise optimized in this manner.
A further significant contribution to the invention is that a plurality of waste-gas outlet elements is provided, in particular in a region of a waste-gas vent, at a spacing from one another and preferably aligned perpendicular to the continuously cast bars or continuously cast billets in order to homogenize a waste gas stream in the perpendicular vertical direction, so that an axial flow of the gas through the waste gas duct does not impair or interfere with the homogeneous heating process.
In a further illustrated embodiment of the present invention, the waste gas stream may also be used to preheat the continuously cast bars or continuously cast billets, where here as well corresponding shafts that are stationarily supported and driven outside a waste gas duct are positioned above the waste-gas vent and take over the axial transport of the continuously cast bars or continuously cast billets.
In this manner a corresponding installation that has very low energy consumption and that enables superior homogeneous heating processes may be operated very consistently with regard to the bearing and drive elements.

Further advantages, features, and particulars of the invention result from the following description of preferred illustrated embodiments, and with reference to the drawing wherein:

FIG. 1 is a schematically illustrated side view of an installation for treating continuously cast bars or continuously cast billets;

FIG. 2 is a schematically illustrated front view of part of the installation for treating continuously cast bars or continuously cast billets;

FIG. 3 is a schematically illustrated perspective view of part of the installation for treating continuously cast bars or continuously cast billets;

FIG. 4 is a schematically illustrated perspective view of the continuous casting installation according to FIG. 3, with additional waste-gas outlet elements installed; and

FIG. 5 is a schematically illustrated top [sic] view of a further illustrated embodiment of an installation for treating continuously cast bars or continuously cast billets according to FIG. 2.

Specific description FIG. 1 schematically illustrates the supply of at least one continuously cast bar 1 or at least one continuously cast billet 2 to an installation R₁via a conveyor 3.
Upstream [sic] from the installation R₁, in preparation for subsequent pressing in a press 4, the continuously cast bar 1 or continuously cast billet 2 is heated to a deformation temperature to a temperature of approximately 480° C. to 510° C.
Upon exiting the installation R₁a slug 6 is sheared from the continuously cast bar 1 or continuously cast billet 2 by a shear 5, and the slug is then pressed in the press 4 to form a semifinished product, for example.
For optimizing the deformation process, as illustrated in particular in FIG. 2, in the present invention it has proven to be particularly advantageous to radially extend a plurality of shafts 8 through a furnace 7, the shafts 8 preferably having a tapered or profiled design inside the furnace 7 in order to hold or support different sizes of continuously cast bars 1 or continuously cast billets 2.
It has proven to be particularly advantageous for corresponding bearings 9 and/or drive elements 10 to be stationarily mounted outside the furnace 7, in particular outside its combustion chamber 11.
As shown in particular in the illustrated embodiment according to FIG. 3, a number of shafts 8 that preferably extend through the furnace 7 in an approximately off-center manner are provided at a spacing from one another in order to move at least one continuously cast bar 1 or at least one continuously cast billet 2 in the illustrated direction X of the double arrow.
Insulation 12 is provided inside the combustion chamber 11.
In the present invention it has also proven to be particularly advantageous that a plurality of gas burners 13 is provided in the combustion chamber 11 in a radially circumferential manner in essentially the entire region, and the gas burners preferably extend through the insulation 12, thereby enabling the continuously cast bar 1 or the continuously cast billet 2 to be heated preferably on all sides.
To enable homogenization, in particular optimal heat distribution and heating, i.e., homogeneous heating, of the continuously cast billet 2 or the continuously cast bar 1, it has proven to be particularly advantageous to provide a first array 14 of radially circumferential gas burners 13, a second array 15 of radially circumferential gas burners 13 being offset, preferably alternatingly offset, with respect to the first array 14, observed in the axial direction. The continuously cast bar 1 or the continuously cast billet 2 may be homogeneously and continuously heated in this manner.
A waste-gas vent 16 that preferably is continuous is provided in the furnace 7 or in the combustion chamber 11 in an upper region, preferably above the continuously cast bar 1 or the continuously cast billet 2. A waste gas duct 17 is provided above the waste-gas vent 16 through which the waste gas is discharged, preferably axially.
In the present invention it has also proven to be particularly advantageous, as illustrated in FIG. 4, in particular to ensure an optimized homogeneous heating process for the continuously cast bar 1 or the continuously cast billet 2, to insert a plurality of waste-gas outlet elements 19 in a region 18 close to or in the waste-gas vent 16 in the furnace 7 that ensures discharge preferably perpendicular to the furnace 7, i.e.—perpendicular to the continuously cast bar 1 or the continuously cast billet 2, resulting in a homogenized flow inside the waste gas duct 17. In this manner the exhaust flow process is homogenized, so that the gas flowing through the waste gas duct 17 does not impair the homogeneous heating process for the continuously cast billet 2 or the continuously cast bar 1.
The individual waste-gas outlet elements 19 that are separate from one another by the same or different spacings, may be axially positioned in the region 18 of the waste gas duct for the waste-gas vent 16, or may be completely or at least partially fitted therein.
It is also within the scope of the present invention that these individual waste-gas outlet elements 19 are manually movable in order to ensure different spacings from adjacent waste-gas outlet elements.
It is also within the scope of the present invention to automatically change the spacings between the individual waste-gas outlet elements, the spacings between individual waste-gas outlet elements being able to be the same or different. The invention is not limited thereto.
In a further illustrated embodiment of the present invention, according to FIG. 5 an installation R₂is shown that approximately corresponds to the type described above. In that case, for preheating a continuously cast billet 2 or a continuously cast bar 1 an additional array of shafts 8 is provided above the furnace 7, preferably above its waste-gas vent 16, in the manner previously described, the additional shafts 8 also being positioned at a spacing from one another over the entire length of the furnace 7 and also being supported and driven outside a waste gas duct 17 by means of bearings 9 and drive elements 10.
The waste gas from the furnace 7 is thus used to preheat the continuously cast bars 1 or the continuously cast billets 2 that in the above-described manner may be moved in and out of the waste gas duct 17 by means of the shafts 8 so that, after preheating, the continuously cast bars or continuously cast billets may be transferred into a transfer unit (not illustrated) to the furnace 7 for heating to the deformation temperature. In this manner the continuously cast bars 1 and continuously cast billets 2 may be heated with very low energy consumption.
Here as well, it is within the scope of the present invention that waste-gas outlet elements 19 may be fitted or positioned in the region of the waste-gas vent 16 in the manner described above.


PARTS LIST - 23756

	continuously cast bar	1
	continuously cast billet	2
	transport element	3
	press	4
	shear	5
	slug	6
	furnace	7
	shafts	8
	bearings	9
	drive elements	10
	combustion chamber	11
	insulation	12
	gas burners	13
	array	14
	array	15
	waste-gas vent	16
	waste gas duct	17
	region	18
	waste-gas outlet elements	19
		20
		21
		22
		23
		24
		25
		26
		27
		28
		29
		30
		31
		32
		33
		34
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		41
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		48
		49
		50
		51
		52
		53
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		57
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		60
		61
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		64
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		68
		69
		70
		71
		72
		73
		74
		75
		76
		77
		78
		79
	installation	R₁
	installation	R₂
	double arrow	X

Claims

1. An installation for treating continuously cast bars or continuously cast billets that may be heated in a furnace to a deformation temperature before shearing to form slugs and subsequent pressing in a press wherein a plurality of shafts for axially transporting continuously cast bars or continuously cast billets extends radially through the furnace, the shafts being stationarily positioned and supported outside the furnace.

2. The installation according to claim 1 wherein the plurality of shafts is separated by an axial spacing from one another and linearly positioned, the individual shafts extending radially through the furnace, in particular through combustion chambers and insulation thereof.

3. The installation according to claim 2, wherein each shaft is externally and stationarily supported on both sides outside the combustion chambers and insulation by means of bearings and drives.

4. The installation according to claim 1, wherein at least one shaft, in particular all shafts, are actively driven-together or separately in a controllable manner outside the furnace, individual or correspondingly common conveying elements rotationally driving the shafts.

5. An installation for treating continuously cast bars or continuously cast billets that may be heated in a furnace to a deformation temperature before shearing to form slugs and subsequent pressing in a press, wherein a plurality of gas burners is arrayed over the entire circumference of the furnace.

6. The installation according to claim 5 wherein the plurality of gas burners is distributed over the circumference in the combustion chambers and insulation in a completely radially circumferential manner, this array of gas burners preferably being provided between two adjacent shafts.

7. The installation according to claim 5 wherein a plurality of arrays together with completely radially circumferential gas burner arrays is provided over the entire length of the furnace.

8. The installation according to at claim 5 wherein the individual gas burners in a circumferential array are angularly offset with respect to the adjoining circumferential array.

9. The installation according to claim 5 wherein, with respect to a first array of completely radially circumferential gas burners, a subsequent array of radially circumferential gas burners that is axially offset with respect to the first array is also angularly offset, preferably always alternatingly offset.

10. An installation for treating continuously cast bars or continuously cast billets that may be heated in a furnace to a deformation temperature before shearing to form slugs and subsequent pressing in a press wherein a plurality of waste-gas outlet elements is provided at an axial spacing from one another in a region of a waste-gas vent.

11. The installation according to claim 10 wherein the waste-gas outlet elements in the region of the waste-gas vent are fitted into the region at an axial spacing from one another, and are aligned approximately in a perpendicular, inclined, or curved manner with respect to a transport direction of the continuously cast bars or continuously cast billets.

12. The installation according to claim 10 wherein the respective waste-gas outlet elements are fitted directly into the waste-gas vent, in the region of the combustion chambers and insulation.

13. The installation according to claim 10 wherein the plurality of waste-gas outlet elements is mounted above a waste-gas vent.

14. The installation according to claim 10 wherein the individual waste-gas outlet elements are separated by the same or different axial, selectable spacings from one another, a spacing between adjacent waste-gas outlet elements being able to be manually or automatically changed.

15. An installation for treating continuously cast bars or continuously cast billets that may be heated in a furnace to a deformation temperature before shearing to form slugs and subsequent pressing in a press wherein for direct preheating of a continuously cast bar or continuously cast billet to be heated, the continuously cast bar and/or continuously cast billet may be guided above a waste-gas vent in the furnace in the region of a waste gas duct.

16. The installation according to claim 15 wherein a plurality of shafts is provided above the waste-gas vent for axially transporting continuously cast bars or continuously cast billets, and is positioned transverse to the furnace, i.e., transverse to the waste gas duct.

17. The installation according to claim 15 wherein the plurality of shafts is stationarily supported outside the furnace and/or outside the waste gas duct, the shafts being driven outside the furnace and/or outside the waste gas duct.

18. The installation according to claim 15, wherein the shafts are separated by an axial spacing from one another and extend through the waste gas duct and/or furnace in a radial, i.e., transverse, manner, the ends of the shafts being externally stationarily supported and driven outside the waste gas duct and furnace.

19. The installation according to claim 15 wherein a plurality of waste-gas outlet elements separated by an axial spacing from one another is provided in a region of a waste-gas vent, the continuously cast bar or the continuously cast billet on the shafts being heatable above the waste-gas outlet elements.

20. The installation according to claim 15, wherein after the continuously cast bar or the continuously cast billet is heated, the bar or billet may be delivered via a conveyor to the furnace for tempering to the deformation temperature, whereby the preheated continuously cast bar or the preheated continuously cast billet may be delivered via the shafts to a transfer unit that supplies the bar or billet to the furnace for heating to the deformation temperature.