Field of the Invention

The invention relates to an arrangement for casting from the bottom of metal/steel according to the preamble of claim 1. Background of the Invention

Casting from the bottom of metal is done by feeding melted metal/steel from below to one or several mould(s), such as cast iron mould(s) . By casting from the bottom scabs, plashes and wave formations are avoided at the surface of the melted metal/steel in the cast iron mould(s), by which is achieved that the melted metal/steel is filled into the cast iron mould(s) evenly and controlled, and this result in a better and more even structure of the ingot .

When casting from the bottom is performed one or more cast iron mould(s) for casting ingots having adequate shape and size is (are) placed on plates, preferably of cast iron, a so called bottom plate, in which there are channels provided with refractory material, preferably refractory bricks.

The channels are arranged to extend from a central distributor having a standing trumpet, which is higher than the cast iron moulds on the bottom plate, to respective cast iron mould. This means that the channels in the bottom plate, as seen in the flow direction of the melted metal/steel, first extend vertically downwardly, and then are angled so as to extend horizontally and then again are angled so as to extend

vertically upwardly so as to discharge in the bottom of respective cast iron mould placed on the bottom plate. When performing the casting a suitable amount of the melted

metal/steel is thus charged into the central distributor and flows through the channels and up into respective cast iron mould, whereby these are filled simultaneously to a suitable level, which is the same for all cast iron moulds, whereupon the metal/steel is allowed to solidify (freeze) .

A problem with casting from the bottom is that the metal/steel solidifies in the channels. This results in that, when the ingot with cast iron mould is removed for stripping, the ingot on its underside is stuck/attached to the metal solidified in the channel leading to the cast iron mould, and this metal strand must be pulled into two/cut off. This makes it

difficult to on one hand remove the cast iron mould with attached ingot from the bottom plate and on the other hand to remove the ingot from the cast iron mould. The thus formed metal strand on the underside of the ingot is, in the

description and claims below, termed jet. When casting brittle metals this jet will be broken off relatively easily, while when casting tough metals this jet must be mechanically removed from the ingot by a cutting torch, for instance.

At subsequent working the ingot such as milling or renewed heating, for instance, this jet may present a problem if it is not removed in a correct way.

Summary of the Invention

Thus, the object of the invention is to eliminate the above- mentioned disadvantages at least partly. This object is achieved by an arrangement for casting from the bottom of metal/steel, comprising a distributor for

distributing melted metal/steel, at least one mould arranged on a bottom plate having at least one channel provided with refectory material, which channel is adapted to, as seen in the flow direction of the melted metal/steel, first extend essentially vertically downwardly from the distributor, then essentially horizontally and then essentially vertically upwardly so as to discharge in the bottom of the mould and to convey the melted metal/steel from the distributor to the mould for casting an ingot, and a dividing device comprising a body having essentially the same cross section area as the channel and is adapted to be driven into the channel, when the flow of melted metal/steel has almost stopped or has stopped so as to divide the channel, characterized in that the

dividing device is placed along the channel and comprises a second channel part extending vertically upwardly to an upper surface of the bottom plate, and a third channel part in the form of a blind hole extending in the opposite direction relative to the second channel part and in line with the second channel part, that the body, in the non-divided state, is placed in the third channel part, that a means is arranged in the third channel part, which means extends to at least the bottom of the third channel part and makes it possible for the melted metal/steel to flow to the underside of the body, that the body has a density which is lower than the density of the melted metal/steel, that the body is provided with an

inclined upper surface which inclines upwardly, as seen in the flow direction of the melted metal/steel, and that the body is adapted to be brought into the second channel part by floating up into the second channel part, when the flow of melted metal/steel has almost stopped or has stopped.

Brief Description of the Drawings

The invention is described in more detail below in the form of non-limiting examples, reference being made to the appended drawings, in which

- Fig. 1 is a schematic, partially sectioned side view showing a cast iron mould with ingot placed on a bottom plate with a non-divided refractory channel for metal,

- Fig. 2 shows the same view as in Fig. 1 but with divided refractory channel for metal,

- Fig. 3 illustrates a sectional view in larger scale of a part of the refractory channel for metal for dividing the refractory channel, the channel being shown in the non-divided state,

- Fig. 4 illustrates the same sectional view as in Fig. 3 but with the dividing device in divided stat of the metal strand,

- Fig. 5 is a schematic, partially sectioned side view showing a cast iron mould mould with ingot placed on a bottom plate with non-divided refractory channel for metal according to one embodiment according to the invention, and

- Fig. 6 is a view similar to the one shown in Fig. 5 with floating state of the body for dividing the refractory

channel .

Description of Preferred Embodiments Fig. 1 shows schematically a partially sectional side view of an arrangement 1 for casting from the bottom of metal/steel. The arrangement 1 comprises a central distributor (not shown) with a trumpet for distributing melted metal/steel, preferably melted steel, to at least one cast iron mould 2 arranged on a bottom plate 3. Usually, a number of cast iron moulds 2 are arranged on one and the same bottom plate. The bottom plate is provided with at least on channel 4 for metal and provided with refractory material, preferably refractory bricks, which channel 4 is adapted to, as seen in the flow direction of the melted metal, first extend essentially vertically downwardly from the distributor, then essentially horizontally and then essentially vertically upwardly so as to discharge on the upper side 5 of the bottom plate 3 and thereby in the bottom 6 of respective cast iron mould 2.

When casting is performed a suitable amount of melted

metal/steel is charged into the distributor, whereby the metal/steel flows through the refractory channels 4 and fills at the same time all cast iron moulds 2 to the same level, whereupon the metal is allowed to freeze to form an ingot 7.

According to the invention a device 10 for dividing/blocking the refractory channel to respective cast iron mould is arranged below the upper side 5 of the bottom plate 3. The dividing device 10 according to the invention may be arranged on one hand in the channel 4 which extends further to

additional cast iron moulds and on the other hand at the end of the channel 4, and in the last mentioned case preferably below the cast iron mould, or the dividing device 10 may at the same time be arranged at one or several places along the channel 4 and/or the channel parts 4a, 4b provided with

refractory material between the distributor and the cast iron mould . In the description below the dividing device 10 is described and shown below a cast iron mould 2.

The dividing device 10 comprises a portion of the refractory channel 4, which ends in the bottom 6 of the cast iron mould 2, which portion in the description below is termed muzzle stone 11.

As can be seen from Figs. 1 and 2 the muzzle stone is made of an elongation or a final stone of the channel 4 and forms at least the portion of respective channel 4 which ends in the bottom 6 of the cast iron mould 2. The muzzle stone 11 is at least provided with on one hand a first channel part 4a, which extends essentially horizontally and which constitutes an elongation of the channel 4, and on the other hand a second channel part 4b, which extends essentially vertically and which ends at the upper side 5 of the bottom plate 3. The muzzle stone is provided also with a third channel part 4c which extends in the opposite direction to the second channel part 4b and in line with the same. In the third channel part 4c a body 12 for dividing the channel is arranged. This body 12 is preferably uniform and consists of a material which resists the temperature of the melted metal/steel.

In one embodiment the body 12 is displaceable arranged by an actuating device 13, in the form of a pneumatic cylinder 13, for instance, which is adapted to be actuated by compressed air or noble gas, so that the upper portion 12a of the body 12 may be located in the second channel part 4b, whereby the channel is divided. See Fig. 2. In this divided state of the body 12 a lower portion 12b of the body 12 is still located in the channel part 4c for sealing this channel part 4c towards the actuating device. For this object the channel parts 4b and 4c and the body 12 have essentially the same cross section area and shape, i.e. the body 12 fits tight in both channel parts.

In Fig. 3 the dividing device 10 and the muzzle stone 11 with body 12 are shown in the non-divided state, while in Fig. 4 the body 12 is shown in the divided state. As shown in said figures the channel parts 4b and 4c, the body 12 and the actuating device 13 are arranged in line with each other, and the dividing of the channel is made preferably in the vertical direction . Furthermore, as seen in Fig. 4, in the divided state of the channel by the dividing device 10, a jet 20 is formed at the bottom of the ingot 7 (not shown) . This jet 20 extends into the second channel part 4b and will have a fixed length depending upon how far the body 12 is pushed/driven into the second channel part 4b, i.e. the longer the body 12 is

pushed/driven into the second channel part 4b the shorter the jet will be. It is obvious for the man skilled in the art that if the body 12 is pushed/driven so far into the second channel that its upper end is flush with the upper surface 5 of the bottom plate 3 the length of the jet will be nil.

By the fact that the jet 20 gets a defined, short length or no length at all the ingot with cast iron mould can be removed from the bottom plate without the feed for pulling off/cutting the solidified metal strand, as in the prior art is formed in the channel 4. By this way the ingot with cast iron mould can easily be transported to a stripping site without any

undesired remains of the metal strand being attached to the ingot . In a preferred embodiment of the device 10 for dividing the channel 4 the third channel part 4c is shaped as a blind hole, see Figs. 5 and 6. Means 14 is arranged in the third channel part 4c, which means extends to at least the bottom of the third channel part 4c and which means makes it possible for melted metal/steel to flow to and below the underside of the body 12. This means 14 may consist of at least one groove or channel 14, for instance, and is arranged at the leading edge, as seen in the flow direction of the melted metal/steel, or at any other portion of the third channel part 4c. This groove extends to the bottom of the third channel part 4c and

possibly below at least a portion of the body 12. See Fig. 5. Alternatively, the means 14 may be formed as a space 14 between the body 12 and the third channel part 4c, which space may extend wholly or partly around the circumference of the third channel part 4c.

The body 12 is preferably provided with wholly or partly inclined upper surface 12c, which surface inclines upwardly as seen in the flow direction of the melted metal/steel, and has a density which is lower than the density of the melted metal/ steel .

In the above-mentioned embodiment, when performing casting, the flowing force of the melted metal/steel will act upon the upper surface of the body 12, and particularly upon the inclined surface 12c of the body 12, in case the body is provided with such inclined surface, and thereby push down the body 12 into the third channel part 4c, while some melted metal/steel will flow into the means 14 and below the body 12, which acts to lift the body 12. More particularly, the

inclined surface 12c of the body 12 and/or the density of the body 12 shall be adapted to the density of the melted metal, so that, as long as the melted metal/steel flows in the channel 4, the lifting force of the body 12 is lower than the flowing force of the melted metal/steel, and when the flow of melted metal/steel in channel 4 has almost stopped or has stopped the body 12 will float up into the second channel part 4b and divided channel 4. To prevent the body 12 from floating up too far into the second channel 4b and/or from turning/rotating, so that the inclined surface 12c no longer is placed in an optimal angle towards the flow direction of the melted metal/steel, the body 12 is provided at a lower portion of the same with at least one shoulder 15 adapted to run in a corresponding groove 15a formed in at least the third channel part 4c. In the preferred embodiment the cross section of the second and third channel part 4b, 4c and the body 12 is preferably circular .