GB2292999A

GB2292999A - Furnace with workpiece stacking

Info

Publication number: GB2292999A
Application number: GB9517670A
Authority: GB
Inventors: Robert Willian Gronbech
Original assignee: Davy McKee AG
Current assignee: Davy McKee AG
Priority date: 1994-09-12
Filing date: 1995-08-30
Publication date: 1996-03-13
Also published as: GB9517670D0

Abstract

A furnace for elongate metal workpieces has a chamber 7 with inlet/s 8 and outlet/s 9 at opposite ends. Elongate platforms 5 are arranged in the chamber. Means are provided so that each platform receives and supports one workpiece in turn and in turn the workpieces are moved out of the outlet/s. The furnace may have two platforms 5. In this instance the platforms may be simultaneously tilted about axes 6 between first and second positions. In the first position one end of the upper platform is adjacent the inlet 8 and the other end of the lower platform, is adjacent the outlet 9. In the second position (Fig. 1c) the other end of the upper platform is adjacent the outlet 9 and the one end of the lower platform is adjacent inlet 8. There may be more than two platforms with a corresponding number of positions. Alternatively the platforms may be fixed and tilting tables (33, 34, Figure 3) may be providing for loading and unloading. <IMAGE>

Description

FURNACES This invention relates to furnaces for heat treating elongate metal workpieces.

During the hot rolling of metal workpieces a hot workpiece of certain dimensions is rolled to a workpiece of different dimensions. A typical example is the continuous casting of molten metal to form a slab which is cut into lengths and each length is passed in turn into a multistand finishing mill where the slab is rolled down to strip.

Between the caster and the finishing mill the slabs reside on a roller table awaiting their turn to enter the finishing mill. There is a continuous heat loss by conduction and radiation from the slabs as they lie on the roller table.

The front end of a slab exiting from the caster will necessarily be on the roller table for a longer time than the back end of the slab and consequently the front end will be at a lower temperature than the back end. For metallurgical reasons it is desirable that the workpiece entering the finishing mill should be at a substantially uniform, predetermined, temperature along its entire length.

It has been proposed to position an enclosure over the roller table to reduce the heat loss by convection from the workpiece when it resides on the roller table. The enclosure is constructed from heat insulating panels.

It has also been proposed to construct the enclosure in the form of a furnace with means therein for heating the workpiece as it resides in the enclosure.

The slabs awaiting entry to the finishing mill are of considerable length, 50-70 metres for example, and if two or more slabs have to be arranged end-to-end on the roller table, the length of the table has to be correspondingly increased.

It is an object of the present invention to provide a compact furnace for elongate metal workpieces which can accommodate two or more workpieces simultaneously.

According to the present invention a furnace for elongate metal workpieces comprises a chamber having an inlet at one end, an outlet at the opposite end and at least two elongate support platforms located within the chamber, each platform being capable of supporting an elongate metal workpiece, means whereby elongate metal workpieces moving in the direction of their length can be directed through the inlet end of the chamber and on to the platforms in turn so that each platform receives and supports one workpiece at a time and means whereby workpieces supported on the platforms can be directed in turn in the direction of their length through the outlet end of the chamber.

In one embodiment of the invention two platforms are provided one above the other and each is pivoted along its length at a substantially central position so that it acts as a see-saw. One end of one platform is adjacent the inlet so that the incoming workpiece moves onto the platform while the opposite end of the other platform is adjacent the outlet so that a workpiece previously supported on the platform can be driven out through the outlet of the furnace. The two platforms are tilted together so that a workpiece previously stored on the first platform can be driven out through the inlet and the end of the second platform is adjacent the outlet to receive another workpiece.

In an alternative embodiment of the invention three platforms are arranged in a vertical stack and the platforms are supported at each end so that they can be moved in unison to bring one end of each platform in turn to a position adjacent the inlet so as to receive a workpiece entering the furnace and as a workpiece is received on one platform the opposite end of another platform is adjacent the outlet so that a workpiece supported on that platform can be driven out of the furnace through said outlet.

In a further embodiment of the invention, the platforms are fixed in a stack and pivoted means are provided upstream of the inlet end of the chamber to direct elongate workpieces in turn onto the platforms and pivoted means are provided downstream of the outlet end of the chamber to receive workpieces leaving in turn through the outlet end of the chamber.

In order that the invention may be more readily understood it will now be described, by way of example only, with reference to the accompanying drawings in which: Figures 1A, 1B and 1C show diagrammatically the operation of a see-saw furnace in accordance with one embodiment of the invention and Figures 2A-2F show diagrammatically the operation of a stacking furnace in accordance with another embodiment of the invention.

Figure 3 shows diagrammatically another embodiment of the invention.

Referring to Figure 1, reference numeral 1 represents apparatus which is either a roughing mill in which elongate metal workpieces are rolled or a shear by which a continuously cast workpiece such as a slab is cut into convenient lengths.

Reference numeral 2 represents a multistand hot finishing mill in which the workpieces received from the apparatus 1 are reduced to strip. The apparatus 1 and the finishing mill 2 are connected by a roller table 3. The roller table includes a furnace 4 which is capable of receiving two elongate workpieces on two support platforms 5.

The two platforms are each of a length which can accommodate one workpiece and the two platforms are arranged in parallel spaced apart relation one above the other. Each platform is pivoted about a horizontal axis 6. The platforms are located in the furnace chamber 7 which has an inlet 8 at the end adjacent the apparatus 1 and an outlet 9 at the opposite end adjacent the mill 2. Means (not shown) in the furnace chamber are capable of raising the temperature of workpieces stored in the chamber.

The two platforms are pivoted together about the axes 6 between a first position in which one end of the first platform is adjacent the inlet and the opposite end of the second platform is adjacent the outlet and a second position in which the end of the second platform is adjacent the inlet and the end of the first platform is adjacent the outlet.

A workpiece 10 enters the furnace from the apparatus 1 and is driven by pinch rolls or the like onto the upper platform 5 as shown in Figure 1A.

Another workpiece 11 which has previously been driven onto the lower platform is driven out by motorised rolls and pinch rolls and the like through the outlet 9 and to the finishing mill. When the workpiece 10 has come to rest on the upper platform and the workpiece 11 has been removed from the lower platform as shown in Figure 1B, the two platforms are tilted together to the position shown in Figure lC. From this position, the workpiece 10 can be brought to the required temperature and then driven out of the furnace whilst at the same time a new workpiece 12 can enter the furnace and come to rest on the lower platform.

Referring now to Figure 2 of the accompanying drawings, the furnace 24 between the apparatus 1 and the mill 2 (neither of which are shown) has three platforms 21, 22 and 23 mounted in vertical spaced apart relation within the chamber 7. Each support platform is capable of receiving and supporting one elongate workpiece of say 70 metres in length and adjacent platforms are separated by a distance of say one metre. The corresponding ends of the three platforms are secured together and are movable vertically in guides provided in the chamber. The means for moving the platforms is not shown but can be any suitable mechanical device driven by electric or hydraulic motors.

In the arrangement shown in Figure 2A a workpiece 25 is driven through the inlet 8 and onto the end of platform 21 which is adjacent to the inlet. When the workpiece is fully supported on the platform 21 as shown in Figure 2B, the ends of the platforms adjacent the inlet 8 are lowered so that the end of platform 22 becomes adjacent the inlet and the opposite ends of the platforms are raised so that the end of platform 22 is adjacent the outlet. The next workpiece 26 is driven onto platform 22.

When workpiece 26 is fully supported on platform 22, the platforms are moved so that the end of platform 23 is adjacent the inlet 8 and the opposite end of platform 21 is adjacent the outlet 9. In this position as shown in Figure 2C, the workpiece 25 can be driven out of the furnace through the outlet 9 while at the same time a new workpiece 27 can be driven through the inlet onto platform 23. The workpiece 26 remains on hold on the platform 22.

Figure 2D shows the hold position in which workpieces 26 and 27 are supported on platforms 22 and 23 respectively.

From the position shown in Figure 2D, the platforms are moved again so that platform 21 has one end adjacent the inlet to receive the next workpiece 28 and the end of platform 22 is adjacent the outlet so that workpiece 26 can be driven through to the outlet 9. The last step in the sequence is to allow the next workpiece 29 to enter the furnace onto platform 22 and for the workpiece 27 on platform 23 to be driven out of the furnace as shown in Figure 2F.

In the figure 2 arrangement pinch rolls and motorised rollers on the platforms allow the workpieces to enter and leave the furnace.

In the arrangement shown in figure 3 a plurality of platforms 30, 31 and 32 are arranged one above the other in the furnace. The platforms are fixed. At the ingoing side of the furnace there is an elongate table 33 which is pivotable so that its end adjacent the furnace can be brought into relation with each of the platforms in turn.

Similarly on the outgoing side of the furnace another tilting table 34 is provided and again the end nearest to the furnace can be brought into relation with the platforms in turn. Thus in use, workpieces are supplied along the roller table and up the tilting table and onto the uppermost platform in the furnace. The tilting table is then pivoted so that it is in relation with the next platform and the next workpiece is fed onto that platform. This is repeated until all the platforms have been filled. At the same time workpieces are taken one at a time from the platforms and along the tilting table 34 at the outgoing side of the furnace.

The invention permits a number of metal workpieces to be within the furnace, other than in end-to-end relation, at the same time. This allows the workpieces to be brought to the correct operating temperature without the need for providing an exceptionally long furnace as would be the case if the workpieces were heated in end-to-end relation.

Clearly more than three platforms could be employed in the furnace.

Claims

Claims:

1. A furnace for elongate metal workpieces comprising a chamber having an inlet at one end, an outlet at the opposite end and at least two elongate support platforms located within the chamber, each platform being capable of supporting an elongate metal workpiece, means whereby elongate metal workpieces moving in the direction of their length can be directed through the inlet end of the chamber and on to the platforms in turn so that each platform receives and supports one workpiece at a time and means whereby workpieces supported on the platforms can be directed in turn in the direction of their length through the outlet end of the chamber.

2. A furnace as claimed in claim 1 wherein said platforms are movable in unison such that one end of each platform is brought in turn to a position adjacent the inlet where the platform can receive the workpiece and the opposite end of each platform is brought in turn to a position adjacent the outlet.

3. A furnace as claimed in claim 2 wherein two platforms are located within the chamber one above the other and each is pivoted along its length at a substantially central position so that it acts as a see-saw.

4. A furnace as claimed in claim 1 wherein at least three platforms are arranged in a vertical stack and the platforms are supported at each end so that they can be moved in unison to bring one end of each platform in turn to a position adjacent the inlet and at the same time to bring the opposite end of a different platform adjacent to the outlet.

5. A furnace as claimed in claim 4 wherein the platforms are secured together in parallel vertical spaced apart relation and the respective ends of the platforms are movable in vertical guides.

6. A furnace as claimed in claim 1 wherein at least three platforms are arranged in a stack in parallel vertical spaced apart relation, the platforms are fixed and pivoted means are provided upstream of the inlet end of the chamber to direct elongate workpieces in turn onto the platforms and pivoted means are provided downstream of the outlet end of the chamber to receive workpieces leaving in turn through the outlet end of the chamber.

7. A furnace for elongate metal workpieces substantially as hereinbefore described with reference to figure 1, or figure 2 or figure 3 of the accompanying drawings.