CA2169320A1 - Tundish - Google Patents
TundishInfo
- Publication number
- CA2169320A1 CA2169320A1 CA002169320A CA2169320A CA2169320A1 CA 2169320 A1 CA2169320 A1 CA 2169320A1 CA 002169320 A CA002169320 A CA 002169320A CA 2169320 A CA2169320 A CA 2169320A CA 2169320 A1 CA2169320 A1 CA 2169320A1
- Authority
- CA
- Canada
- Prior art keywords
- filter
- tundish
- molten metal
- region
- feeding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/116—Refining the metal
- B22D11/119—Refining the metal by filtering
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/003—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like with impact pads
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/02—Refining by liquating, filtering, centrifuging, distilling, or supersonic wave action including acoustic waves
- C22B9/023—By filtering
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
In a tundish (1) for receiving and filtering of melts of iron-type metals, comprising an outlet (5) in the bottom region for discharging the molten metal after passing through reversing and/or filtering means, there is mounted a ceramic filter (3) being removable in a manner known per se and covering essentially the whole horizontal section of the tundish (1) in the tundish (1), which filter (3) extends essentially in horizontal direction and is provided with openings (4), which are arranged in an essentially vertical direction being the flow direction of the molten metal through the tundish (1), whereby with a simple construction a purification or filtering of molten metals can be achieved also for high casting velocities. (Fig. 1)
Description
The present invention relates to a tundish for receiving and filtering of melts of iron-type metals, comprising an outlet in the bottom region for discharging the molten metal after passing through a reversing and/or filtering means.
Such tundishes, which are also known as intermediate vessels or intermediate ladles, are used as well in the continous casting as also in the discontinous casting of molten metals. It is known to treat lten metal, especially steel, in such tundishes or at least to secure that a major part of the impurities, especially slag, is removed from the melt or that such impurities or slags are settled and that they can easily be removed from the melt thereafter.
A device for filtering metallic melts is known for example from DE-OS 35 09 113. In this known embodiment two plates are arranged in flow direction of the molten metal and are spaced apart from another, wherein the bores of the plates are offset and a chamber for allaying the flow is provided between this plates. Hereby it is assumed that the sepa-ration of impurities of a metallic melt requires some time and therefore the flow of the melt near the filtering device should be allayed by reduction of the flow rate, whereby it is also desired to achieve a diversion of the melt by displacing the passage bores, which should favour the settling procedures.
Another embodiment of an intermediate vessel or tundish for receiving or filtering of molten metal, such as steel, can be gathered from EP-A 0 376 526, in which a filter element with nearly vertically directed passing slits is provided, wherein the molten metal is supplied on one side of this element and is withdrawn from the intermediate vessel or tundish on the other side of the filter element. Also with this embod;m4nt it is aimed to a diversion or reversion of the flow direction of the melt for favouring the separation of impurities, whereby further a baffle is provided which projects from the surface of the melt for exactly separating the distinct regions of the tundish. With adequate baffles in the bottom region it is also possible to achieve an additional turbulence of the melt.
According to a further known embc~;r^~t of a tundish for receiving and purifying of a metal melt of US-PS 5 071 107 it is envisaged that for achieving a laminar flow the melt passes through a baffle, which shows openings in essentially horizontal direction, whereafter a filter element is pro-vided around the outlet of the tundish. The essential part of the filter action should take place within a filter element which is arranged in essentially vertical direction, so that the melt passes through essentially horizontally directed holes or bores in the filter. Unfavourable with this known embodiment is the fact that it is possible that a great amount of impurities or slags can accumulate and solidify in the region directly in front of the filter, which may lead directly to a clogging of the filter element.
In this case it is necessary to replace the tundish or to remove the settled and cooled impurities in a time-consuming manner.
Considering this known prior art the present invention aims to provide a simple device for filtering-off a high-quality molten metal by maint~i n; ng a high pouring or casting rate, whereby at the same time a clogging of the tundish with solidified slag should be avoided. For solving this problem the tundish according to the present invention is especially characterised in that a ceramic filter being removable in a manner known per se and covering essentially the whole horizontal section of the tundish is mounted in the tllnAi~h, which filter extends essentially in horizontal direction and is provided with openings, which are arranged in an essentially vertical direction being the flow direction of the molten metal through the tundish. Because of the fact that the cer~m;c filter covers essentially the whole horizontal section of the tundish a sufficiently large effective flow area for the molten metal is provided, so that the filtering may be effected in a sufficiently short time. By using an adequate ceramic filter, which should be removable and therefore simply replaceable, it was found that for sufficiently removing the impurities or slag it is not necessary to divert and allay the flow or to achieve a l~minar flow in the melt, so that according to the present invention the filter being arranged essentially in horizontal direction provides a respective large effective area. Furthermore, according to the present invention the filter is provided with openings which are arranged in an essentially vertical direction corresponding to the flow direction of the molten metal, so that the introduced melt can pass through the filter as rapidly as possible only under the action of gravity. Altogether it is therefore possible to perform a very rapid filtering and purifying with the inventive tundish, because it is possible to renounce a comparatively long time of allaying and diverting the melt in the tlln~;~h, as this was necessary according to the prior art. Because of the fact that only the horizontally arranged filter is arranged in the tundish, it is at the same time avoided that the solidifying slag can be deposited on vertical baffles of the tlln~;Rh and that thereby the total volume of the tlln~;~h is drastically reduced.
For avoiding that by the introduction of the molten metal in the tlln~;~h slag is directly introduced or pressed into the filter element, which covers essentially the whole cross-section of the tlln~;~h, according to a preferred embodiment the construction is characterised in that in the region of feeding the molten metal an impact means, especially a splash core, is arranged in a plane being aligned with the filter or lying above the filter. Such impact means, especially a splash core, which is arranged in a plane being aligned with the filter or lying above the filter, avoids thereby a direct impact of the melt on the filter and at the same time causes a more uniform distribution of the molten metal on the filter of the tlln~;sh, so that thereafter nearly the whole filter area can be used for passing and purifying the molten metal.
In case that the impact means, especially the splash core, is arranged above the plane of the filter advantageously essentially the whole horizontal cross-section of the tun-dish can be covered by the filter and can be used forpassing and purifying of the molten metal. For a careful charging of the molten metal in the tundish the embodiment is preferably characterised in that the surface of the impact means, which is directed to the region of feeding the molten metal, is arranged above the plane of the filter in a distance of less than half of the height of the bath of the lten metal, especially about a third of the height of the bath. With this arrangement of the impact means it is possible to largely avoid turbulences when feeding the molten metal into the molten metal which is already cont~;ne~ in the tundish and moreover there is provided a sufficient volume below the impact means and between the impact means and the filter so that a solidification of the melt can be avoided in this area.
For a very simple and easy change of the filter according to a preferred embodiment the tundish is characterised in that the filter is mounted in an e~changeable frame known per se, which is arranged in a region of the bottom of the tlln~;~h or which forms the bottom of the tundish. In case that the impact means, especially the splash core, is arranged in the plane of the filter also the impact means can be comprised in the frame so that by changing the filter the impact means is changed at the same time. In case that the impact means is arranged in a plane above the filter, the frame is provided with the filter element. By arranging the filter element in an exchangeable frame, which is arranged in the region of the bottom of the tundish or which forms the bottom of the tundish, there is guaranteed a simple and easy e~change of the filter and also a fast renewed use of the tlln~;sh. Therefore only a shorter standstill of the tlln~i~h for exchanging the filter must be taken into account. This allows essential savings of time compared with embodiments, in which solified deposits being formed in the region of baffles or of filter elements being arranged essentially in vertical direction, as was the case according to the prior art, had to be removed. Therefore according to the invention the active time of the tundish is essentially independent of the active t; m~ of the much che~rer filter.
For being able to use essentially unchanged filter elements for receiving invariable steel qualities in different scopes of use and different casting or pouring velocities according to another preferred embodiment of the invention the cross-sectional area of the filter is variable by aperture elements. Such aperture elements, which may be used for changing the active cross-sectional area of the filter, may be for example s;mlpy inserted into the frame comprising the filter, so that by choosing the clear opening of the filter, which is defined by the aperture elements, respective flow rates of the melt are adjustable. By suitably choosing the active passing area of the filter the time of direct contact of the molten metal in the tundish may be also influenced at the s~mP time. Almost independently of the desired passing area, the whole filter area may be completely used, if suc-cessively different cross-sectional areas of the filter are opened by the aperture elements.
For avoiding a soli~;f;c~tion of the melt in the filter even with low flow velocities of the molten metal and therefore a long holding time thereof, the embodiment is furthermore preferably characterised in that a heating device is arranged in the region of the filter and/or the impact means. Such a heating device, which, in principle, should heat only the region of the filter or the filter itself or the impact means, can thereby built relatively small and energy saving. A heating device for the impact means may be especially favourable, if it is arranged above the plane of the filter.
For nearly completely avoiding an oxidation or other chemical reactions in the melt after passing through the filter the embodiment is preferably characterised in that at least one feed opening for feeding an inert gas into the purified molten metal is provided under the plane of the filter.
Particularly when using the inventive tundish in a continous casting procedure a sufficient output of floating impurities and of slag may be secured. For achieving this object accor-ding to the invention the tundish is preferably further improved in that an outlet or an offset region of the side wall for withdrawing the slag is provided on a front wall of the tundish, being opposite to the feeding of the molten metal.
For maint~;n;ng a sufficient pouring or casting rate and at the same time totally removing the slag the embodiment is furthermore preferably characterised in that the pores of the ceramic filter and/or the whole cross-sectional area of the filter are selected in such manner that a flow rate of about 0,01 to 1,0 kg melt/cm2s, especially at least 0,25 kg melt/cm2s is achievable.
Especially in discontinous casting procedures it may be ne-cessary to check the permeabilty of the filter after the complete passing of the molten metal through the filter for determining, if optionally a replacement of the filter is necessary before a further casting procedure. A simple check of the permeability of the filter may be achieved with com-pressed air, whereby for this purpose according to the invention the embodiment is characterised in that above the filter a device for feeding compressed air and downstream of the filter a sensor are mountable on the tundish for measuring the amount compressed air passing through the filter after complete removal of the molten metal.
The inventive tundish is further explained on the basis of examples being shown in the accompanied drawings, in which:
Fig. 1 shows a schematical cross section through an inven-tive tundish;
Fig. 2 shows a top view of the inventive tundish in the direction of arrow II to the embodiment of Fig.l, wherein Fig. 1 is a section according to line I-I of Fig.2; and Fig.3 is a similar view of a schematical section through an alternative embodiment of an inventive tundish.
In Figures 1 and 2 a tundish is generally designated with 1, into which via a feed line 2, especially a refractory pipe or a refractory casting gutter, molten metal is fed from a converter or a ladle, which are not shown. After passing of the lten metal through a removeable filter 3 covering es-sentially the complete section of the tundish 1 and exten-ding essentially in horizontal direction and being provided with openings extending essentially in vertical direction, which are indicated schematically with 4, the molten metal is removed through a discharge opening 5 from a funnel-shaped bottom portion 6 of the tlln~i ~h 1. In a plane being essentially aligned with the plane of the filter 3 there is provided an impact means, for example a splash core 7, in the area of the feed line 2, whereby it is prevented that lten metal being fed through the feed pipe 2 directly hits the filter 3 and that the included impurities and slags directly obstruct the filter 3 in this area.
Simply the filter 3 is mounted in an exchangeable frame 8, being arranged in the bottom area of the tundish 1 or being formed as an intermediate bottom, as is schematically indi-cated in Fig. 2. This frame 8 may be additionally providedwith aperture elements 9 and 10, whereby it is possible to change the effective passing area of the filter in the sense of double arrows 11 and 12 through simple translational movement of the aperture elements. By changing the position of the aperture elements 9 and 10 the effective passing area of the filter 3 can be adjusted to the needs, for e~ample a predetermined casting velocity etc..
For avoiding that an excessive cooling and thereby a solidification of the melt occurs in the area of the filter 3 even with relatively low passing velocities through the filter 3, whereby the filter 3 is occluded by the soli-difying melt or solidifying impurities, there is further provided a heating device 13 in the area of the filter 3, as is schematically indicated in Fig. 1. This heating device 13 may be only provided in the area of the peripheral wall of the tundish 1 or can also be coupled with respective heating devices in the frame 8 comprising the filter 3 to maintain the desired temperature of the filter 3.
For largely preventing undesired chemical reactions in the molten metal after passing through the filter 3 there is additionally provided a feeding opening 14 in the funnel-shaped bottom portion 6 of the tundish 1 for introducing aninert gas into the purified melt.
Particularly when using the tundish 1 for a continous casting process it is necessary that accumulating impurities or slag floating on the molten metal can be removed from the tnn~; ~h 1, wherefore a discharge opening 15 is provided on a wall of the tundish 1 being arranged opposite of the feed line 2. Instead of such a discharge opening 15 there can also be provided an offset region in the upper portion of this front wall.
For preventing a splashing of the molten metal when intro-ducing the same into the tundish and for further preventing an excessive cooling of the molten metal during filtering or purifying in the tundish 1 there is further provided a covering or a lid 16, which may be lifted or lowered according to double arrow 17.
When using the tundish 1 in discontinous casting processes it might be necessary to check the penetrability of the filter 3 between individual casting steps to decide if an exchange of the filter 3 by simple removal of the frame 8 is necessary. Such a check of the penetrability of the filter 3 can be done with compressed air, wherein after completely discharging the melt out of the tundish 1 there is injected compressed air onto the filter 3, as is schematically indi-cated by the feeding line 18, whereafter the penetrability of the filter 3 being achieved is detected by a sensor 19 being arranged in the outlet 5.
In the embodiment of Fig. 3 the numerals of the prec~e~;ng figures have been maint~;n~ for similar elements. In this embodiment of a tundish 1 an impact means 7 being formed as a splash core is arranged above the filter 3, wherein the surface 20 of the impact means 7 facing the feed line 2 for the molten metal is slightly inclined relative to the horizontal plane and is arranged at a level, which amounts to nearly a third of the bath height h of the melt in the tundish 1. For surely preventing a solidification of the melt and/or impurities in the area of the impact means 7 there is further provided a heating device 21 in the area of the impact means 7. With this embodiment for discharging the slag there is provided an offset portion on the front wall being opposite to the feed line 2 and being schematically indicated with 22.
Such tundishes, which are also known as intermediate vessels or intermediate ladles, are used as well in the continous casting as also in the discontinous casting of molten metals. It is known to treat lten metal, especially steel, in such tundishes or at least to secure that a major part of the impurities, especially slag, is removed from the melt or that such impurities or slags are settled and that they can easily be removed from the melt thereafter.
A device for filtering metallic melts is known for example from DE-OS 35 09 113. In this known embodiment two plates are arranged in flow direction of the molten metal and are spaced apart from another, wherein the bores of the plates are offset and a chamber for allaying the flow is provided between this plates. Hereby it is assumed that the sepa-ration of impurities of a metallic melt requires some time and therefore the flow of the melt near the filtering device should be allayed by reduction of the flow rate, whereby it is also desired to achieve a diversion of the melt by displacing the passage bores, which should favour the settling procedures.
Another embodiment of an intermediate vessel or tundish for receiving or filtering of molten metal, such as steel, can be gathered from EP-A 0 376 526, in which a filter element with nearly vertically directed passing slits is provided, wherein the molten metal is supplied on one side of this element and is withdrawn from the intermediate vessel or tundish on the other side of the filter element. Also with this embod;m4nt it is aimed to a diversion or reversion of the flow direction of the melt for favouring the separation of impurities, whereby further a baffle is provided which projects from the surface of the melt for exactly separating the distinct regions of the tundish. With adequate baffles in the bottom region it is also possible to achieve an additional turbulence of the melt.
According to a further known embc~;r^~t of a tundish for receiving and purifying of a metal melt of US-PS 5 071 107 it is envisaged that for achieving a laminar flow the melt passes through a baffle, which shows openings in essentially horizontal direction, whereafter a filter element is pro-vided around the outlet of the tundish. The essential part of the filter action should take place within a filter element which is arranged in essentially vertical direction, so that the melt passes through essentially horizontally directed holes or bores in the filter. Unfavourable with this known embodiment is the fact that it is possible that a great amount of impurities or slags can accumulate and solidify in the region directly in front of the filter, which may lead directly to a clogging of the filter element.
In this case it is necessary to replace the tundish or to remove the settled and cooled impurities in a time-consuming manner.
Considering this known prior art the present invention aims to provide a simple device for filtering-off a high-quality molten metal by maint~i n; ng a high pouring or casting rate, whereby at the same time a clogging of the tundish with solidified slag should be avoided. For solving this problem the tundish according to the present invention is especially characterised in that a ceramic filter being removable in a manner known per se and covering essentially the whole horizontal section of the tundish is mounted in the tllnAi~h, which filter extends essentially in horizontal direction and is provided with openings, which are arranged in an essentially vertical direction being the flow direction of the molten metal through the tundish. Because of the fact that the cer~m;c filter covers essentially the whole horizontal section of the tundish a sufficiently large effective flow area for the molten metal is provided, so that the filtering may be effected in a sufficiently short time. By using an adequate ceramic filter, which should be removable and therefore simply replaceable, it was found that for sufficiently removing the impurities or slag it is not necessary to divert and allay the flow or to achieve a l~minar flow in the melt, so that according to the present invention the filter being arranged essentially in horizontal direction provides a respective large effective area. Furthermore, according to the present invention the filter is provided with openings which are arranged in an essentially vertical direction corresponding to the flow direction of the molten metal, so that the introduced melt can pass through the filter as rapidly as possible only under the action of gravity. Altogether it is therefore possible to perform a very rapid filtering and purifying with the inventive tundish, because it is possible to renounce a comparatively long time of allaying and diverting the melt in the tlln~;~h, as this was necessary according to the prior art. Because of the fact that only the horizontally arranged filter is arranged in the tundish, it is at the same time avoided that the solidifying slag can be deposited on vertical baffles of the tlln~;Rh and that thereby the total volume of the tlln~;~h is drastically reduced.
For avoiding that by the introduction of the molten metal in the tlln~;~h slag is directly introduced or pressed into the filter element, which covers essentially the whole cross-section of the tlln~;~h, according to a preferred embodiment the construction is characterised in that in the region of feeding the molten metal an impact means, especially a splash core, is arranged in a plane being aligned with the filter or lying above the filter. Such impact means, especially a splash core, which is arranged in a plane being aligned with the filter or lying above the filter, avoids thereby a direct impact of the melt on the filter and at the same time causes a more uniform distribution of the molten metal on the filter of the tlln~;sh, so that thereafter nearly the whole filter area can be used for passing and purifying the molten metal.
In case that the impact means, especially the splash core, is arranged above the plane of the filter advantageously essentially the whole horizontal cross-section of the tun-dish can be covered by the filter and can be used forpassing and purifying of the molten metal. For a careful charging of the molten metal in the tundish the embodiment is preferably characterised in that the surface of the impact means, which is directed to the region of feeding the molten metal, is arranged above the plane of the filter in a distance of less than half of the height of the bath of the lten metal, especially about a third of the height of the bath. With this arrangement of the impact means it is possible to largely avoid turbulences when feeding the molten metal into the molten metal which is already cont~;ne~ in the tundish and moreover there is provided a sufficient volume below the impact means and between the impact means and the filter so that a solidification of the melt can be avoided in this area.
For a very simple and easy change of the filter according to a preferred embodiment the tundish is characterised in that the filter is mounted in an e~changeable frame known per se, which is arranged in a region of the bottom of the tlln~;~h or which forms the bottom of the tundish. In case that the impact means, especially the splash core, is arranged in the plane of the filter also the impact means can be comprised in the frame so that by changing the filter the impact means is changed at the same time. In case that the impact means is arranged in a plane above the filter, the frame is provided with the filter element. By arranging the filter element in an exchangeable frame, which is arranged in the region of the bottom of the tundish or which forms the bottom of the tundish, there is guaranteed a simple and easy e~change of the filter and also a fast renewed use of the tlln~;sh. Therefore only a shorter standstill of the tlln~i~h for exchanging the filter must be taken into account. This allows essential savings of time compared with embodiments, in which solified deposits being formed in the region of baffles or of filter elements being arranged essentially in vertical direction, as was the case according to the prior art, had to be removed. Therefore according to the invention the active time of the tundish is essentially independent of the active t; m~ of the much che~rer filter.
For being able to use essentially unchanged filter elements for receiving invariable steel qualities in different scopes of use and different casting or pouring velocities according to another preferred embodiment of the invention the cross-sectional area of the filter is variable by aperture elements. Such aperture elements, which may be used for changing the active cross-sectional area of the filter, may be for example s;mlpy inserted into the frame comprising the filter, so that by choosing the clear opening of the filter, which is defined by the aperture elements, respective flow rates of the melt are adjustable. By suitably choosing the active passing area of the filter the time of direct contact of the molten metal in the tundish may be also influenced at the s~mP time. Almost independently of the desired passing area, the whole filter area may be completely used, if suc-cessively different cross-sectional areas of the filter are opened by the aperture elements.
For avoiding a soli~;f;c~tion of the melt in the filter even with low flow velocities of the molten metal and therefore a long holding time thereof, the embodiment is furthermore preferably characterised in that a heating device is arranged in the region of the filter and/or the impact means. Such a heating device, which, in principle, should heat only the region of the filter or the filter itself or the impact means, can thereby built relatively small and energy saving. A heating device for the impact means may be especially favourable, if it is arranged above the plane of the filter.
For nearly completely avoiding an oxidation or other chemical reactions in the melt after passing through the filter the embodiment is preferably characterised in that at least one feed opening for feeding an inert gas into the purified molten metal is provided under the plane of the filter.
Particularly when using the inventive tundish in a continous casting procedure a sufficient output of floating impurities and of slag may be secured. For achieving this object accor-ding to the invention the tundish is preferably further improved in that an outlet or an offset region of the side wall for withdrawing the slag is provided on a front wall of the tundish, being opposite to the feeding of the molten metal.
For maint~;n;ng a sufficient pouring or casting rate and at the same time totally removing the slag the embodiment is furthermore preferably characterised in that the pores of the ceramic filter and/or the whole cross-sectional area of the filter are selected in such manner that a flow rate of about 0,01 to 1,0 kg melt/cm2s, especially at least 0,25 kg melt/cm2s is achievable.
Especially in discontinous casting procedures it may be ne-cessary to check the permeabilty of the filter after the complete passing of the molten metal through the filter for determining, if optionally a replacement of the filter is necessary before a further casting procedure. A simple check of the permeability of the filter may be achieved with com-pressed air, whereby for this purpose according to the invention the embodiment is characterised in that above the filter a device for feeding compressed air and downstream of the filter a sensor are mountable on the tundish for measuring the amount compressed air passing through the filter after complete removal of the molten metal.
The inventive tundish is further explained on the basis of examples being shown in the accompanied drawings, in which:
Fig. 1 shows a schematical cross section through an inven-tive tundish;
Fig. 2 shows a top view of the inventive tundish in the direction of arrow II to the embodiment of Fig.l, wherein Fig. 1 is a section according to line I-I of Fig.2; and Fig.3 is a similar view of a schematical section through an alternative embodiment of an inventive tundish.
In Figures 1 and 2 a tundish is generally designated with 1, into which via a feed line 2, especially a refractory pipe or a refractory casting gutter, molten metal is fed from a converter or a ladle, which are not shown. After passing of the lten metal through a removeable filter 3 covering es-sentially the complete section of the tundish 1 and exten-ding essentially in horizontal direction and being provided with openings extending essentially in vertical direction, which are indicated schematically with 4, the molten metal is removed through a discharge opening 5 from a funnel-shaped bottom portion 6 of the tlln~i ~h 1. In a plane being essentially aligned with the plane of the filter 3 there is provided an impact means, for example a splash core 7, in the area of the feed line 2, whereby it is prevented that lten metal being fed through the feed pipe 2 directly hits the filter 3 and that the included impurities and slags directly obstruct the filter 3 in this area.
Simply the filter 3 is mounted in an exchangeable frame 8, being arranged in the bottom area of the tundish 1 or being formed as an intermediate bottom, as is schematically indi-cated in Fig. 2. This frame 8 may be additionally providedwith aperture elements 9 and 10, whereby it is possible to change the effective passing area of the filter in the sense of double arrows 11 and 12 through simple translational movement of the aperture elements. By changing the position of the aperture elements 9 and 10 the effective passing area of the filter 3 can be adjusted to the needs, for e~ample a predetermined casting velocity etc..
For avoiding that an excessive cooling and thereby a solidification of the melt occurs in the area of the filter 3 even with relatively low passing velocities through the filter 3, whereby the filter 3 is occluded by the soli-difying melt or solidifying impurities, there is further provided a heating device 13 in the area of the filter 3, as is schematically indicated in Fig. 1. This heating device 13 may be only provided in the area of the peripheral wall of the tundish 1 or can also be coupled with respective heating devices in the frame 8 comprising the filter 3 to maintain the desired temperature of the filter 3.
For largely preventing undesired chemical reactions in the molten metal after passing through the filter 3 there is additionally provided a feeding opening 14 in the funnel-shaped bottom portion 6 of the tundish 1 for introducing aninert gas into the purified melt.
Particularly when using the tundish 1 for a continous casting process it is necessary that accumulating impurities or slag floating on the molten metal can be removed from the tnn~; ~h 1, wherefore a discharge opening 15 is provided on a wall of the tundish 1 being arranged opposite of the feed line 2. Instead of such a discharge opening 15 there can also be provided an offset region in the upper portion of this front wall.
For preventing a splashing of the molten metal when intro-ducing the same into the tundish and for further preventing an excessive cooling of the molten metal during filtering or purifying in the tundish 1 there is further provided a covering or a lid 16, which may be lifted or lowered according to double arrow 17.
When using the tundish 1 in discontinous casting processes it might be necessary to check the penetrability of the filter 3 between individual casting steps to decide if an exchange of the filter 3 by simple removal of the frame 8 is necessary. Such a check of the penetrability of the filter 3 can be done with compressed air, wherein after completely discharging the melt out of the tundish 1 there is injected compressed air onto the filter 3, as is schematically indi-cated by the feeding line 18, whereafter the penetrability of the filter 3 being achieved is detected by a sensor 19 being arranged in the outlet 5.
In the embodiment of Fig. 3 the numerals of the prec~e~;ng figures have been maint~;n~ for similar elements. In this embodiment of a tundish 1 an impact means 7 being formed as a splash core is arranged above the filter 3, wherein the surface 20 of the impact means 7 facing the feed line 2 for the molten metal is slightly inclined relative to the horizontal plane and is arranged at a level, which amounts to nearly a third of the bath height h of the melt in the tundish 1. For surely preventing a solidification of the melt and/or impurities in the area of the impact means 7 there is further provided a heating device 21 in the area of the impact means 7. With this embodiment for discharging the slag there is provided an offset portion on the front wall being opposite to the feed line 2 and being schematically indicated with 22.
Claims (10)
1. Tundish (1) for receiving and filtering of melts of iron-type metals, comprising an outlet (5) in the bottom region for discharging the molten metal after passing through reversing and/or filtering means, characterised in that a ceramic filter (3) being removable in a manner known per se and covering essentially the whole horizontal section of the tundish (1) is mounted in the tundish (1), which filter (3) extends essentially in horizontal direction and is provided with openings (4), which are arranged in an essentially vertical direction being the flow direction of the molten metal through the tundish (1).
2. Tundish according to claim 1, characterised in that in the region of feeding (2) the molten metal an impact means (7), especially a splash core, is arranged in a plane being aligned with the filter (3) or lying above the filter (3).
3. Tundish according to claim 2, characterised in that the surface (20) of the impact means (7), which is directed to the region of feeding (2) the molten metal, is arranged above the plane of the filter (3) in a distance of less than half of the height of the bath (h) of the molten metal, es-pecially about a third of the height of the bath (h).
4. Tundish according to claim 1, 2 or 3, characterised in that the filter (3) is mounted in an exchangeable frame (8) known per se, which is arranged in a region of the bottom of the tundish (1) or which forms the bottom of the tundish (1) -
5. Tundish according to any of the claims 1 to 4, characterised in that the cross-sectional area of the filter (3) is variable by aperture elements (9, 10).
6. Tundish according to any of the claims 1 to 5, characterised in that a heating device (13, 20) is arranged in the region of the filter (3) and/or the impact means (7).
7. Tundish according to any of the claims 1 to 6, characterised in that at least one feed opening (14) for feeding an inert gas into the purified molten metal is provided under the plane of the filter (3).
8. Tundish according to any of the claims 1 to 7, characterised in that an outlet (15) or an offset region of the side wall (22) for withdrawing the slag is provided on a front wall of the tundish (1), being opposite to the feeding (2) of the molten metal.
9. Tundish according to any of the claims 1 to 8, characterised in that the pores (4) of the ceramic filter (3) and/or the whole cross-sectional area of the filter (3) are selected in such manner that a flow rate of about 0,01 to 1,0 kg melt/cm2s, especially at least 0,25 kg melt/cm2s is achievable.
10. Tundish according to any of the claims 1 to 9, characterised in that above the filter (3) a device (18) for feeding compressed air and downstream of the filter (3) a sensor (19) are mountable on the tundish for measuring the amount of compressed air passing through the filter after complete removal of the molten metal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT25795 | 1995-02-13 | ||
| ATA257/95 | 1995-02-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2169320A1 true CA2169320A1 (en) | 1996-08-14 |
Family
ID=3485739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002169320A Abandoned CA2169320A1 (en) | 1995-02-13 | 1996-02-12 | Tundish |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0726115A1 (en) |
| JP (1) | JPH08252666A (en) |
| KR (1) | KR960031024A (en) |
| CN (1) | CN1138507A (en) |
| CA (1) | CA2169320A1 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100530328B1 (en) * | 2001-10-30 | 2005-11-22 | 주식회사 포스코 | Device for recovery ladle slag by using mould oscillation |
| JP4799944B2 (en) * | 2005-07-22 | 2011-10-26 | 産機電業株式会社 | Vacuum melting casting method |
| CN101543880B (en) * | 2009-05-12 | 2011-06-15 | 合肥神马科技股份有限公司 | Casting device for conticaster |
| JP5491902B2 (en) * | 2010-02-24 | 2014-05-14 | 株式会社神戸製鋼所 | Continuous casting apparatus, cast rod manufactured using the same, and method |
| KR101379142B1 (en) * | 2012-05-14 | 2014-03-31 | 주식회사 포스코 | Tundish for continuous casting of steel and method of high purity molten steel using the same |
| KR20150048202A (en) | 2012-09-27 | 2015-05-06 | 바오샨 아이론 앤 스틸 유한공사 | Method and device for continuous thin strip casting |
| CN102974813A (en) * | 2012-12-26 | 2013-03-20 | 烟台孚信达双金属股份有限公司 | Molten aluminum heat-preservation and purification conveying package for copper cladding aluminum horizontal continuous casting |
| CN103567424A (en) * | 2013-11-19 | 2014-02-12 | 李殿明 | Molten metal refinement continuous casting tundish |
| DE102014119109B4 (en) | 2014-12-18 | 2018-12-13 | Voestalpine Stahl Gmbh | Distributor for continuous casting plants |
| CN105537573A (en) * | 2015-12-28 | 2016-05-04 | 南阳汉冶特钢有限公司 | Tundish transformation method and tundish which are capable of improving metal yield |
| CN108889933B (en) * | 2018-07-07 | 2020-11-03 | 池州海琳服装有限公司 | Pouring equipment for steel manufacturing |
| CN109759577A (en) * | 2019-01-29 | 2019-05-17 | 大连交通大学 | The method of intensified by ultrasonic wave metal melt filtering purification |
| CN109604577A (en) * | 2019-01-29 | 2019-04-12 | 大连交通大学 | Ultrasonic wave assisted casting melt filtration purification device |
| CN112170824A (en) * | 2020-10-30 | 2021-01-05 | 张琪 | Tundish for molten steel casting |
| CN113560515B (en) * | 2021-06-21 | 2023-01-03 | 杭州电子科技大学 | Tundish for rare earth magnetic material rapid-hardening casting belt and casting method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2840871A (en) * | 1955-12-09 | 1958-07-01 | Kaiser Aluminam & Chemical Cor | Apparatus and method for casting metal |
| US4032124A (en) * | 1975-03-28 | 1977-06-28 | Swiss Aluminium Ltd. | Apparatus and method for in-line degassing and filtration of molten metal |
| JPS6138911Y2 (en) * | 1980-12-27 | 1986-11-08 | ||
| US4455238A (en) * | 1982-04-14 | 1984-06-19 | Daniel E. Groteke | Apparatus and method for filtration of a molten metal stream |
| DE3618284A1 (en) * | 1986-05-30 | 1987-12-03 | Steuler Industriewerke Gmbh | CARRYING TROUGH FOR INTERCHANGEABLE HIGH-TEMPERATURE METAL MELT FILTERS |
-
1996
- 1996-02-08 KR KR1019960002983A patent/KR960031024A/en not_active Application Discontinuation
- 1996-02-09 CN CN96101269A patent/CN1138507A/en active Pending
- 1996-02-12 EP EP96890018A patent/EP0726115A1/en not_active Withdrawn
- 1996-02-12 CA CA002169320A patent/CA2169320A1/en not_active Abandoned
- 1996-02-13 JP JP8025275A patent/JPH08252666A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| CN1138507A (en) | 1996-12-25 |
| EP0726115A1 (en) | 1996-08-14 |
| JPH08252666A (en) | 1996-10-01 |
| KR960031024A (en) | 1996-09-17 |
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