GB2075937A - A car for transferring hot metal workpieces - Google Patents

Abstract

The car has a plurality of workpiece- supporting rollers 9 arranged side-by-side and panels 15, 16 mounted on the frame form an enclosure which serves to reduce the heat loss from a hot workpiece supported on the rollers. <IMAGE>

Description

SPECIFICATION Transfer car for hot metal workpieces This invention relates to a transfer car for transferring a large hot metal workpiece from a first installation, such as a mill in which it has been formed, to a second installation, such as a mill in which it is to be hot rolled to an elongate product.

The large workpiece may be a billet, slab, bloom, breakdown or the like and the elongate product may be strip, bar or plate.

A particular, but not sole, example is the transfer of a slab produced in a slabbing mill to a hot strip mill. If the transfer can take place without the slab cooling below the permitted rolling temperature, then rolling can be undertaken without the necessity of"topping up"thetemperatureoftheslab. If, however, there is a delay in the transfer and the temperature of the slab falls below the permitted rolling temperature, then the slab has to be taken to a re-heat furnace to be heated to the rolling temperature before rolling can commence. Obviously, it is desirable to avoid having to re-heat the slab.

Normally the hot slabs are transferred from the slabbing mill to the hot strip mill on a transfer car which consists of a plurality of driven rollers arranged side-by-side on a wheeled frame which is movable on a pair of rails. During the time that the slab is supported on the rollers, it is rapidly losing heat to the atmosphere and its temperature soon falls below the permitted rolling temperature.

An object of the present invention is to provide a transfer car which has provision for reducing heat emission from a hot metal workpiece supported thereon.

According to the present invention, a trasfer car comprises a plurality of rollers arranged side-by-side on a displaceable frame and panels mounted on the frame to form an enclosure which serves to reduce the heat loss from a hot workpiece supported on the rollers.

While the panels can be of any suitable refractory material, it is most convenient for the panels to be of a form which will reflect heat back towards the workpiece so that the heat loss from the hot workpiece is reduced as compared with the panels of refractory material which simpiy act as a shield to shield the workpiece from draughts.

It is convenient for the enclosure to be open at its opposite ends so that a workpiece can readily be moved into and out of the enclosure through one or other of the open ends. Preferably, panels are also positioned between adjacent rollers so that heat loss downwardly between the rollers can be reduced.

It is found that, by reducing the heat emission from the slab as it is supported on the car, in many cases the slab can be transferred directly from the slabbing mill to the hot strip and it is unnecessary for the slab to enter into the re-heat furnace. If, however, it does become necessary for the slab to enter into the re-heat furnace, the amount of heat required to bring the slab to the rolling temperature is considerably less than would be the case when the slab has been transferred by a conventional transfer car.

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: Figure 1 is a sectional side elevation of a known slab transfer car, Figure 2 is a part section end elevation of a slab transfer car in accordance with the present invention, and Figure 3 is a sectional side elevation of part of the transfer car shown in Figure 2.

A transfer car for transferring hot slabs from a slabbing mill to a hot strip mill comprises a rigid framework 1 supported on two pairs of wheels 3, one side pair being shown in Figure 1. Drive means in the form of an electric motor 5 and gear box 5' are provided for displacing the car along a set of rails 7.

Supported on the framework 1 there are a plurality of rollers 9 arranged substantially horizontal and at least some of the rollers being rotatable by their own drive motor 11.

Referring now to Figures 2 and 3, such a car has an enclosure which receives the slab and is very largely defined by heat reflective panels mounted on the framework 1. Some of these panels 15 are positioned between adjacent rollers 9 and similar panels are mounted along the sides of the framework which are normal to the length of the rollers 9 and also above the rollers 9. This forms a tunnel enclosure defined by the insulating panels into which the slab is introduced to be supported on the rollers 9. The panels 16 which are positioned above the rollers 9 are mounted on an assembly 17 which is pivotally mounted on the framework 1 and which is provided with an actuator 19 by which the frame and the panels 16 can be pivoted to a position giving access to the rollers 9 for maintenance and inspection.

In operation, a slab is conveyed from the roller table of a slabbing mill on to the rollers 9 of the car.

The car is then driven along the rails to align with the roller table of the hot strip mill. The slab is then driven out of the car on to the entry roller table of the strip mill. If there is a short delay before the strip mill is ready to receive the slab, then the slab will not lose much heat because of the insulating effect of the panels. Should the delay be longer than at first expected, then the car can be driven back to align with a re-heat furnace and the slab is driven into the furnace for topping up to rolling temperature. Even if this is necessary, the reduced heat loss due to the effect of the insulating panels means that less heat is required from the furnace to top up the temperature of the slab.

The run out table of the slabbing mill may be offset from that of the hot strip mill or it may be possible for the slabbing mill and the hot strip mill to be in line but, in either event, a transfer car is provided to transport the slabs from the slabbing mill to the hot strip mill.

Each panel is conveniently composed of a mat or pad of thermally insulating material with the opposite faces of the mat or pad covered with metal plates which provide reflective surfaces. Suitable panels are sold in the United Kingdom by ENCOM ECH LTD.

Claims (8)

1. Atransfer car comprises a plurality of rollers arranged side-by-side on a displaceable frame and panels mounted on the frame to form an enclosure which serves to reduce the heat loss from a hot workpiece supported on the rollers.

2. Atransfer car as claimed in claim 1, wherein the enclosure is open-ended and the rollers are alignable with a roller table whereby transfer of a workpiece between the rollers of the car and the roller table can take place through one of said ends of the enclosure.

3. A transfer car as claimed in claim 1, wherein the frame is mounted on wheels and is displaceable in the direction of the length of the rollers of the car.

4. Atransfer car as claimed in claim 1,2 or 3, wherein panels are located between adjacent rollers.

5. A transfer car as claimed in any preceding claim, wherein some of the panels are readily movable to gain access to the enclosure for maintenance and inspection purposes.

6. Atransfer car as claimed in claim 5, wherein the panels providing the top of the enclosure are mounted on an assembly which is pivotable about the frame.

7. A transfer car as claimed in any preceding claim, wherein each panel has a heat reflecting surface positioned on the inside of the enclosure.

8. A transfer car substantially as hereinbefore described with reference to the accompanying drawings.