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Title:
ARRANGEMENT FOR CASTING FROM THE BOTTOM OF METAL/STEEL
Document Type and Number:
WIPO Patent Application WO/2015/183166
Kind Code:
A1
Abstract:
The invention relates to an arrangement (1) for casting from the bottom of metal/steel, comprising a distributor, at least one mould (2) arranged on a bottom plate (3) with or without at least one intermediate plate (8) having a hole, said bottom plate (3) being provided with at least one channel (4,4a,4b). The channel conveys the melted metal/steel from the distributor to the mould. At least one dividing device (10) comprising a body (10) adapted to be brought into the channel (4b) is placed along the channel (4,4a), a second channel part (4b) extending vertically upwardly and having a tapered portion (4d) closest to an underside of the mould (2), and a third channel part (4c) in the form of a blind hole in which the body is placed before casting. The body (12) 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, and is adapted to get stuck in the tapered portion (4d) of said second channel part (4b).

Inventors:
ERIKSSON, Martin (Lövbergsvägen 11, Falun, S-791 76, SE)
Application Number:
SE2015/050604
Publication Date:
December 03, 2015
Filing Date:
May 26, 2015
Export Citation:
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Assignee:
ERIKSSON, Martin (Lövbergsvägen 11, Falun, S-791 76, SE)
International Classes:
B22D35/04; B22D9/00
Domestic Patent References:
WO2012053476A12012-04-26
WO2014084793A12014-06-05
Foreign References:
SE206524C1
US0129957A1872-07-30
GB1394905A1975-05-21
US0333929A1886-01-05
Other References:
See also references of EP 3148727A4
Attorney, Agent or Firm:
EHRNER & DELMAR PATENTBYRÅ AB (P.O. Box, 100 55 Stockholm, 10316, SE)
Download PDF:
Claims:
Claims

1. An arrangement (1) for casting from the bottom of

metal/steel, comprising a distributor for distributing melted metal/steel, at least one mould (2) arranged on a bottom plate (3) with or without at least one intermediate plate (8) having a hole, said bottom plate (3) being provided with at least one channel (4,4a) provided with refectory material, which channel is adapted to, as seen in the flow direction of melted

metal/steel, first extend essentially vertically downwardly from the distributor, then essentially horizontally and then essentially vertically upwardly so as to discharge in a bottom (6) of the mould (2) and to convey the melted metal/steel from the distributor to the mould for casting an ingot (7), and a at least one dividing device (10) comprising a body (12) adapted to be brought into a channel (4b), when the flow of melted metal/steel has almost stopped or has stopped so as to divide said channel, characterized in that said at least one dividing device (10) is placed along the channel (4,4a) and comprises a second channel part (4b) extending vertically upwardly and having a tapered portion (4d) closest to an underside of the mould (2), and a third channel part (4c) in the form of a blind hole, which extends in the opposite direction to the second channel part (4b) and in line with said second channel part (4b), that the body (12), in the non- divided position of the channel (4), is placed in the third channel part (4c), that at least one means (14) is arranged in the third channel part (4c), which means (14) 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 an underside of the body (12), that the body (12) has a density which is lower than the density of the melted metal/steel, that the body (12) is provided with an inclined upper surface (12c) which inclines upwardly, as seen in the flow direction of the melted metal/steel, and that the body (12) 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, and is adapted to get stuck in the tapered portion (4d) of said second channel part (4b) .

2. The arrangement according to claim 1, characterized in that the intermediate plate (8) having a hole is placed between an underside of the mould (2) and an upper side of the bottom plate (3) and through which plate the second channel part (4b) is arranged to extend.

3. The arrangement according to claim 1 or 2, characterized in that said at least one means (14) is at least one groove (14) arranged at a front edge, as seen in the direction of flow of the melted metal/steel, of the third channel part (4c) and extends to at least the bottom (4e) of the third channel part (4c) . 4. The arrangement according to claim 1 or 2, characterized in that said at least means (14) is a space (14) formed between the body (12) and the third channel part (4c), said space extends wholly or partly around the circumference of the third channel part (4c) .

5. The arrangement according to any one of claims 1-4,

characterized in that the body (12) is free floating in at least the second channel part (4b) . 6. The arrangement according to any one of claims 1-5,

characterized in that the body (12) is provided with an inclined upper surface (12c), and that one of the underside of the body (12) or the bottom (4e) of the third channel part (4c) is provided with a shoulder (16) arranged to be placed in a corresponding groove (15) arranged at one of the underside of the body (12) or in the bottom (4e) of the third channel part (4c) so as to hold said inclined upper surface (12c) of the body (12) towards the direction of flow of the melted metal/steel in the channel (4) .

7. The arrangement according to any one of claims 1-6,

characterized in the second channel part (4b) and the body (12) have such dimensions in relation to each other that there is a suitable space between the external side of the body (12) and the internal side of the second channel part (4b) so that melted metal/steel can flow in this space when the body (12) floats up in the second channel part (4b), and/or at least one through channel (17) is arranged in the body (12) so as to facilitate the flow of melted metal/steel from the upper side to the underside of the body (12), when said body floats up in the second channel part (4b) . 8. The arrangement according to claim 7, characterized in that at least one bar (18) having a fusion temperature higher than the fusion temperature of the metal/steel being cast is connected to the bottom (4e) of the third channel part (4c) and extends through said at least one through channel (17), that a nut (21) is screwed onto a threaded upper portion (19) of the bar (18) so as to hold the body (12) against said bottom (4e) of the third channel part (4c), and that said nut (21) is made of a material having the same or less fusion temperature that the fusion temperature of the metal/steel being cast.

9. The arrangement according to claim 8, characterized in that that an upper portion of said through channel (17) close to said inclined upper surface (12c) has a cavity for

accommodating the nut (21), that said cavity has same depth the height / length of the nut (21), and that said nut (21) is made of a material having similar properties as the

metal/steel being cast.

10. The arrangement according to any one of claims 1-9, characterized in that the body (12) is made of refractory material .

Description:
ARRANGEMENT FOR CASTING FROM THE BOTTOM OF METAL/STEEL

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 a plate, 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 slightly 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.

By the international patent application PCT/SE2013/051417 an arrangement for casting from the bottom of metal/steel is known. This arrangement is particularly adapted for casting from the bottom when the distance from the horizontal

channel (s) in the bottom plate to the underside of the cast iron mould is relatively short.

At certain applications of casting from the bottom it is desirable to place at least one plate between the cast iron mould and the bottom plate for the purpose of protecting the bottom plate. However, this results in that the distance between the bottom of the cast iron mould and the horizontal channel (s) will become larger, whereby the length of the vertical channel, which is situated under the cast iron mould, will be relatively long.

This leads to that the jet formed at casting from the bottom in accordance with this arrangement, which is described in the above-mentioned patent application, will more or less be of the same length as the length of the vertical channel. This jet must then be removed by the method mentioned above, for instance, which involves drawbacks.

Summary of the Invention

Thus, the object of the invention is to eliminate the above- mentioned disadvantages wholly or 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 with or without at least one intermediate plate having a hole, said bottom plate being provided with at least one channel provided with refectory material, which channel is adapted to, as seen in the flow direction of melted metal/steel, first extend essentially vertically downwardly from the distributor, then essentially horizontally and then essentially vertically upwardly so as to discharge in a bottom of the mould and to convey the melted metal/steel from the distributor to the mould for casting an ingot, and a least one dividing device comprising a body adapted to be brought into a channel, when the flow of melted metal/steel has almost stopped or has stopped so as to divide the channel,

characterized in that said at least one dividing device is placed along the channel and comprises a second channel part extending vertically upwardly and having a tapered portion closest to an underside of the mould, and a third channel part in the form of a blind hole, which extends in the opposite direction to the second channel part and in line with said second channel part, that the body, in the non-divided

position of the channel, is placed in the third channel part, that at least one means is arranged in the third channel part, which means extends to at least the bottom of the third channel part and which means makes it possible for molten metal/steel to flow to an 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 and is adapted to get stuck in the tapered portion of said second channel part. 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 plate having a hole, which is placed on a bottom plate having a non-divided

refractory channel for metal/steel according to one embodiment of a dividing device according to the invention,

- Fig. 2 is a view similar to the one shown in Fig. 1 with the body in a floated up position so as to divide the channel,

- Fig. 3 is a sectional view of a further embodiment of a dividing device according to the invention with the body in floated up position so as to divide the channel, and

- Fig. 4 is a view similar to the one shown in Fig. 1 of a further embodiment provided with a time-delay feature. Description of Preferred Embodiments

Figs. 1 and 2 show 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, preferably melted steel, to at least one mould 2, preferably a cast iron mould 2, arranged on a bottom plate 3. In the embodiment shown an intermediate plate 8 having a hole is placed between the cast iron mould 2 and the bottom plate 3. It is obvious to the man skilled in the art that the

intermediate plate 8 having a hole can be formed of two or more plates each having a hole and placed on top of each other and with the holes in line to each other. Usually, a number of cast iron moulds 2 are arranged on one and the same bottom plate with or without intermediate plate 8 having a hole. 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 an upper side 5 of the bottom plate 3 or on an upper side of the intermediate plate 8 having a hole 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 is arranged at the end of the channel 4 and below the 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 end brick 11.

As can be seen from the figures the end brick 11 constitute the 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 end brick 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 or at the upper side of the intermediate plate 8 having a hole.

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. Before the casting

operation is performed a body 12 is placed in the third channel part 4c. This body 12 is preferably uniform and consists of a material which resists the temperature of the melted metal/steel.

In the embodiment shown of the device 10 for dividing the channel 4 the third channel part 4c is formed as a blind hole, see Figs. 1-3. At least one means 14 is arranged in the third channel part 4c, which means extends to at least the bottom 4e of the third channel part 4c and which means makes it possible for melted metal/steel to flow to the underside of the body 12. This means 14 can be formed as at least one groove or notch 14, for instance, arranged at the leading edge, as seen in the flow direction of the melted metal, or in any other part of the third channel part 4c. This groove extends to the bottom 4e of the third channel part 4c and possibly below at least a portion of the body 12. See Fig. 1. Alternatively, the means 14 can be formed as a space 14 between the body 12 and the third channel part 4c, which space 14 extends totally or partially around the circumference of the third channel part 4c. The body 12 is preferably provided with a whole or partially inclined upper surface 12c, which incline obliquely upwardly 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 the 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 then acts to lift the body 12 in combination with the buoyancy of 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/steel, 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 thereby divide said channel part 4b. The characteristic of this body 12 is that it is free floating in at least the second channel part 4b, i.e. it is not guided in said second channel part 4b. The body 12 shall have a length in the vertical direction which is larger than the diameter of the second channel part. In the embodiment shown in Figs. 1-3, an intermediate plate 8 having a hole is placed between the underside of the cast iron mould and the upper side of the bottom plate. However, this results in that the second channel part 4b is relatively long. Therefore, the intermediate plate 8 having a hole is provided with suitable hole through which the refractory bricks with the second channel part 4b extend.

To prevent the body 12 from floating up too far into the second channel 4b, said second channel part 4b is provided with an upper portion 4d, closest to the underside of the cast iron mould, having a smaller/narrower cross section that the cross section of the remaining portion of the second channel part 4b. Thanks to this the body 12 will, when it floats up in the second channel part 4b, get stuck at said upper portion 4d and thereby divide said second channel part 4b. To avoid the body 12 from turning/rotating, when the melted metal/steel flows in the channels 4, resulting in that the inclined surface 12c no longer is placed in an optimal angle towards the flow direction of the melted metal/steel, the underside of the body 12 or the bottom 4e of the third channel part 4c is provided with a shoulder 16 which is adapted to cooperate with a complementary groove 15 arranged at the underside of the body 12 or in the bottom 4e of the third channel part 4c.

As can be seen from Fig. 2, in the divided position of the dividing device 10, a jet 20 is obtained at the bottom of the ingot 7 (not shown) . This jet 20 extends into the upper portion 4d of the second channel part 4b and will have a defined length dependent upon how far the body 12 will float up/rise into the second channel part 4b, i.e. the longer the body 12 will float up in the second channel part 4b the shorter the jet 20 will be.

Thanks to that the jet 20 has a defined short length, the ingot with cast iron mould can easily be removed from the bottom plate 3 and the intermediate plate 8 without the need for pulling into two/cut off the solidified metal strand, which in the prior art is formed in the channel 4. Thanks to this the ingot with cast iron mould is easily transferred to a stripper station without undesired remains of the metal strand will come along with the ingot and the cast iron mould.

To enable the body 12 to float up easily in the second channel part 4b to the upper portion 4d having narrower/smaller cross section and get stuck there, the second channel part 4b and the body 12 is so dimensioned in relation to each other that there is a space/play between the external vertical side of the body 12 and the internal side of the second channel part 4b so that melted metal/steel may flow in the space formed, when the body floats up/rises in the second channel part 4b.

In the embodiment according to Fig. 3 at least one through channel 17 is arranged in the body 12 so as to facilitate flow of metal/steel from the upper side of the body 12 to its underside, when it floats up in the second channel part 4b. This or those through channels 17 may replace or be complementary to said space/play mentioned above between the external vertical side of the body 12 and the internal side of the second channel part 4b.

In case the body 12 is provided with said at least one through channel 17, the solidified metal/steel will, after casting, extend through the body, which results in that the jet 20 is connected to the metal/steel strand in the channel 4/second channel part 4b below the body 12. Since the diameter of said at least one through channel 17 is small compared to the diameter of the channel 4/second channel part 4b this has no or only minor effect at the subsequent stripping operation.

In the same way a thin-walled sleeve of metal/steel may be formed in the space between the external vertical side of the body and the internal side of the second channel part 4b. Also this sleeve has no or only minor effect at the subsequent stripping operation.

Fig. 4 shows a further embodiment of the arrangement 1 for casting from the bottom of metal/steel. In said arrangement the dividing device 10 is provided with a time-delay before the body 12 floats up and blocks the second channel part 4b. The effect of this time-delay is that it is possible to interrupt the casting, i.e. it is possible to partly fill said at least one mould 2 and then interrupt the casting, without run the risk of the body 12 floating up and blocking the second channel part 4b, and then start the casting again. To provide this time-delay at least one bar 18 having a fusion temperature higher than the fusion temperature of the

metal/steel being cast is connected to the bottom 4e of the third channel part 4c and extends preferably through said at least one through channel 17 formed in the body 12. Preferably only one bar 18 is arranged. An upper portion of said through channel 17 close to the inclined upper surface 12c has

preferably a cavity for accommodating a nut/threaded sleeve 21 which is screwed onto a threaded upper portion 19 of the bar 18 so as to hold the body 12 against the bottom 4e of the third channel part 4c during moulding and during a fixed period of time after the flow of molten metal/steel has stopped, started again, and stopped again in the channels. The cavity has preferably the same depth as the height /length of the nut 21, and depending upon the length/height and the fusion temperature of the nut 21 it is possible to control the time-delay before the body 12 floats up and block the second channel part 4b, i.e. when the nut 21 has melted the body 12 is free to float up. The nut 21 should be made of a material having the same or less fusion temperature that the fusion temperature of the metal/steel being cast and preferably of a material having similar properties as said metal/steel being cast. The time-delay is dependent on the length/height of the nut 21, and preferably the nut is tightly fitted in the cavity so that the melted material/steel is primarily acting upon the end of the nut whereby the nut melts successively from its upper end towards its lower end.

In a preferred embodiment the cross section of the channel parts 4b, 4c, the upper portion 4d of the second channel part 4b, and the body 12 is preferably circular.