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
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
• • 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
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0637—Accessories therefor
  • B22D11/0697—Accessories therefor for casting in a protected atmosphere
• • 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
  • B22D11/12—Accessories for subsequent treating or working cast stock in situ
  • B22D11/128—Accessories for subsequent treating or working cast stock in situ for removing
  • B22D11/1287—Rolls; Lubricating, cooling or heating rolls while in use
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D15/00—Casting using a mould or core of which a part significant to the process is of high thermal conductivity, e.g. chill casting; Moulds or accessories specially adapted therefor
  • B22D15/005—Casting using a mould or core of which a part significant to the process is of high thermal conductivity, e.g. chill casting; Moulds or accessories specially adapted therefor of rolls, wheels or the like
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C33/00—Making ferrous alloys
  • C22C33/02—Making ferrous alloys by powder metallurgy
  • C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
  • C22C33/0264—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements the maximum content of each alloying element not exceeding 5%
  • C22C33/0271—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements the maximum content of each alloying element not exceeding 5% with only C, Mn, Si, P, S, As as alloying elements, e.g. carbon steel

Definitions

• the invention relates to a two-roll casting plant with two casting rolls rotating in opposite directions about horizontal axes, with a casting gap for the formation and removal of a thin cast metal strip, with a sealed housing which has a bottom and which the transport path of the metal strip leaving the casting gap from a vertical casting direction bounded in an almost horizontal direction of transport, with diverters for the metal strip in this housing and with a movable scrap collection container for the removal of scrap and scale from the two-roll caster.
• the invention further relates to a method for initiating a casting process using the two-roll casting device according to the invention.
• Two-roll casting machines are used for the production of metal strips, preferably steel strips, with a wide range and with a strip thickness of less than 10 mm in a continuous casting process.
• metal strips preferably steel strips
• strip thickness of less than 10 mm
• a two-roll casting installation of the generic type is already known from WO 02/11924. It consists of two casting rolls rotating in opposite directions about horizontal axes of rotation, which together with side plates that can be placed on the end of the casting rolls form a melting space and a casting gap from which a cast metal strip is conveyed vertically downwards.
• the cast metal strip is deflected into the horizontal to form a sagging loop and fed to one or more further treatment devices. Leaving the casting gap, the hot metal strip passes through a sealed chamber with a protective gas atmosphere, through which oxidation processes on the surface of the metal strip are largely avoided. All openings in this chamber are provided with sealed gates or locks.
• the sealed chamber also includes a space open to the casting rolls for receiving a movable scrap wagon, which can be brought into a receiving position for the scrap and scale below the two casting rolls and removed from there via a lock system which can be flooded with protective gas ,
• a lock system which can be flooded with protective gas .
• large lock gates In order to manipulate the scrap car, large lock gates must be opened and large rooms accommodating the scrap car must be flooded with protective gas. Furthermore, complex sealing systems for the large lock gates must be installed.
• a pivotable guide flap for the cast metal strip is also known, which in an operating position supports the diversion of the metal strip into the horizontal and to a drive roller stand and, in a retracted position, enables the vertical derivation of a strand piece into the scrap bucket.
• Such a solution is also known from WO 01/23120.
• the object of the present invention is therefore to avoid the disadvantages of the known prior art and to propose a two-roll casting installation and a method for initiating a casting process using a two-roll casting installation, which makes it possible to keep the space insulated with protective gas for the passage of a hot metal strip as small as possible and at the same time to enable the continuous collection of scrap and any scale that may occur without or with very little leakage from the housing.
• Another object of the invention is to design the two-roll casting installation in such a way that the scrap or scale that is collected can be discharged with very little air entry into the insulated housing.
• the bottom of the housing forms a collecting trough for the scrap, which is part of an emptying device, and that a movable scrap collecting container is arranged in a receiving position below the emptying device.
• the emptying device comprises at least one collection trough for receiving the scrap, at least one support for this collection trough on a supporting frame or on the housing, which enables the collection trough to be actuated between a closed and an open position, and at least one adjusting drive for relocating the collection trough to be able to carry out an emptying and, if necessary, necessary seals in order to avoid the entry of false air into the housing.
• An expedient embodiment consists in the fact that the collecting trough for the scrap can be displaced between a closed and an open position and is coupled to an adjusting drive and that the housing has a sealing element for sealing a gap between the housing and the collecting trough in the closed position is assigned.
• the collecting trough can be made in one piece or in several parts and the emptying can be carried out by a displacement movement, preferably in the case of a one-piece design, or by a pivoting movement about one or more pivot axes, preferably in the case of a multi-part design.
• An adjusting lever is assigned to the collecting trough, which can be formed by a controllable pressure medium cylinder or by at least one driven undercarriage wheel.
• the sealing elements effective between the housing and the collecting trough are expediently fastened to the housing and can be pressed against the housing in the closed position. Damage to the sealing element during the manipulation of the collecting trough and in particular during scrap unloading is thus avoided.
• a preferred embodiment of the sealing element consists in that the sealing element comprises a sealing ring which is movable relative to the housing and the collecting trough and can be pressed onto the collecting trough, which is carried by a displacement element which engages on the housing and is fastened to it, and which is coupled to a controllable displacement device.
• the displacement element can be formed, for example, by a bellows or another elastic element permitting a longitudinal extension
• the controllable displacement device can be formed, for example, by a pressure medium cylinder articulated on the housing.
• the collecting trough expediently has a trolley and a trolley, in particular rails, is assigned to this trolley.
• the distance between the collecting trough and the housing or the sealing element fastened to the housing can preferably be reduced to such an extent that a sealing closed position automatically or simultaneously with the approach to the closed position on the last section of the displacement path a small displacement of the sealing element is achieved.
• the collecting trough has sliding elements and a stationary slideway is assigned to these sliding elements.
• the closed can be started simultaneously with Position on the last section of the displacement path, the distance between the collecting trough and the housing or the sealing element fastened to the housing can be reduced to such an extent that a sealing closed position is achieved.
• a clearing sword is arranged at a distance from the collection trough on the housing for stripping off the scrap accumulated in the collection trough.
• the distance between the clearing sword and the collecting trough is selected so that there is no jamming of scrap parts between the stationary clearing sword and the collecting trough.
• the clearing sword can slide on the trough. For emergencies, the clearing sword can be retracted transversely to the shifting movement of the collecting trough.
• the collecting trough comprises a receiving area for the scrap, which can be designed differently.
• the receiving area for the scrap can be formed by a flat surface, the associated clearing sword having a straight clearing edge which is arranged at a short distance from the surface of the receiving area or slides on it.
• the receiving area for the scrap can also be designed as a trough-shaped depression, this depression preferably being on three sides of the collecting trough and on the fourth side, on which the emptying of the collecting trough takes place, the trough-shaped depression essentially runs out horizontally. Emptying with the help of a clearing sword, the clearing edge of which is adapted to the cross section of the trough-shaped depression, is equally possible.
• a sealing element assigned to the housing is designed such that it can be pressed against the movable scrap container in its receiving position when the collecting trough is in the open position.
• a further improvement of the seal can be achieved if a seal between the mobile scrap collection container and the housing is ensured on at least three sides during the ongoing displacement process of the collecting trough. This is achieved with a multi-part sealing element. In this way, it is expedient to minimize the air entry if a sealing element assigned to the housing is designed to be able to be pressed in its receiving position continuously or with sections on the mobile scrap container during the opening of the collecting trough.
• the harmful air minimization can be achieved if the housing is assigned a single circumferential sealing element, which is designed to be able to be pressed against the mobile waste container when the collecting container is in the closed position and against the mobile waste container when the container is in the open position.
• the harmful air minimization can be achieved if two mutually independent sealing elements are assigned to the housing, one of these sealing elements being designed to be able to be pressed against this collecting trough when the collecting trough is in the closed position, and the second sealing element is capable of being pressed against the mobile scrap collection container.
• the two sealing elements are preferably fastened concentrically to one another on the outer wall of the housing and can be actuated independently of one another.
• a further reduction in the remaining, very low, entry of harmful air can be achieved if the mobile scrap collection container is positioned in its receiving position in a closed scrap chamber, which sealingly connects to the housing below it.
• a treatment chamber with a strip transport device for example a roller table, and optionally further strip treatment devices for the metal strip, for example a temperature compensation furnace in front of a roll stand, adjoin the housing flooded with protective gas, the bottom of this treatment chamber being emptied by at least one Collecting container for scale and possibly scrap, for example trimming scrap from a band trimming system, is formed.
• a strip transport device for example a roller table
• further strip treatment devices for the metal strip for example a temperature compensation furnace in front of a roll stand
• the collecting container is preferably designed as a collecting trough with a closing device and can be formed, for example, by a funnel-shaped collecting bunker with a closing flap.
• One or more receiving positions for a movable scrap collecting container are provided under the collecting containers.
• the mobile scrap collection container is equipped with a drive control, which enables a controlled approach to all pick-up positions below the transport path of the metal strip.
• the recording positions are determined, for example, by electrical sliding contacts or light barriers.
• an operating method for initiating a casting process is proposed, which enables the derivation and removal of a first section of the cast metal strip, which is produced in an unsteady start phase of the two-roll casting plant and does not yet meet the quality requirements of the product to be produced.
• a scrap manipulation is proposed that minimizes the entry of false air during this start-up phase as much as possible, but also allows the subsequent production steps and scrap removal from the plant with minimized air access.
• the actual starting procedure can be done in different ways.
• molten metal is introduced into the melt chamber up to an operational casting level and the metal strip is started to be conveyed out during this filling process.
• This process can start with standing or already rotating casting rolls.
• the width of the casting gap can also differ from that of an operating casting gap.
• the filling process in the melt chamber, the casting speed and the casting gap width can follow a predetermined start-up curve.
• the first section thus produced under transient casting conditions is separated under the effect of the dead weight of this strip section.
• the casting speed and the width of the casting gap can follow a curve.
• a preferred starting method for the casting process in a two-roll casting plant without taking the scrap industry into account has already been described in detail in the Austrian patent application AT-A 1367/2002 and should be regarded as an integral part of this application.
• Fig. 1 shows a longitudinal section through a two-roll casting machine with an inventive
• FIG. 2 shows an embodiment of a sealing element between the housing and a
• FIG. 3 a first operating case of the two-roll casting plant according to the invention
• Fig. 4 a second operating case of the two-roll casting plant according to the invention
• Fig. 5 a third operating case of the two-roll casting plant according to the invention
• Fig. 6 a further embodiment of a sealing element between the housing and a collecting bowl or a scrap container.
• Fig. 1 shows a schematic representation of a two-roll casting plant of the type according to the invention for the continuous production of a steel strip.
• the two-roll casting plant With its core device for forming the metal strip, the two-roll casting plant consists of two driven casting rolls 1, 2 rotating in opposite directions about horizontal axes, which together with two side plates 3, only one of which is shown in FIG. 1, one Form melt chamber 4 for the reception of molten metal, which is fed from an intermediate vessel 5 via a dip tube 6 into the melt chamber 4 and forms a melt bath there.
• the melt chamber 4 is largely sealed airtight with a cover 7, which enables a protective gas atmosphere to be maintained above the melt bath.
• the two cooled casting rolls 1, 2 and the side plates 3 lying against the end faces of the casting rolls form a casting gap 8, from which the metal melt previously solidified on the casting roll surfaces in the form of strand shells is conveyed out as a cast metal strip 9 in the vertical casting direction and deflected in a horizontal transport direction a drive roller stand 10 is fed to various further processing devices in the direction of the arrow.
• a pivotable skid-shaped diverter 11 is provided below the casting gap 8, which is shown from a threading position shown with thick lines, in which the metal strip 9 is diverted to the drive roller frame 10, into a substantially vertical one with dash-dotted lines Treatment position can be pivoted. In this retracted position, strip sections, such as occur at the start and end of casting, can be disposed of as scrap vertically downwards.
• the transport path of the metal strip 9 from the exit from the casting gap 8 to the entry into the drive roller frame 10 is delimited by a housing 13, which is usually formed by sheet metal walls with a refractory lining on the inside.
• a housing 13 In the entry area of the metal strip into the housing 13, seals, not shown, are provided between the wall of the housing and the casting rolls 1, 2 and the side plates 3, as described in the Austrian patent application AT-A 303/2002.
• the housing 13 is sealed by a treatment chamber 14, likewise flooded with protective gas, in which the metal strip is transported further on a roller table 15 and fed to further treatment devices, not shown.
• the bottom 16 of the housing 13 forms an emptying device 17 and is formed in an area below the casting gap 8 by a collecting trough 18, in which falling, short strip sections separated from the production process and scale which occasionally falls off from the cast metal strip are collected.
• the start-up piece of the cast metal strip formed at the start of casting during an unsteady start phase does not meet the required product requirements and is therefore at least partially not diverted into the horizontal transport direction for further processing to the first drive roller stand, but rather is diverted directly vertically downward into the collecting trough 18.
• the collecting trough 18 has a trough-shaped receptacle for the scrap and is equipped with a chassis 19 which comprises bicycles 20 which roll on a roadway 21 formed by a horizontal longitudinal member or a rail. Via a hinged, controllable shifting device 22, which is formed by a long-stroke pressure medium cylinder 23, the collecting trough 18 can be displaced from a closed position shown in thick lines for receiving the scrap into a retracted open position shown in dash-dotted lines. With a clearing sword 27, which is arranged at a short distance above the collecting trough 18 and transversely to its direction of displacement, the accumulated scrap is removed from the collecting trough during the displacement movement into the open position and brought into a scrap collecting container 25 provided underneath.
• the scrap collecting container is inserted in a traveling frame 28 and can be manipulated on the two-roll casting machine independently of the ongoing production process.
• an adjustable sealing element 30 is arranged between these components.
• a possible embodiment is shown schematically in FIG. 2 in a partial section. 2 shows a partial area of the lower end of the housing 13 and the collecting trough 18 for the scrap positioned at a distance below it.
• a circumferential support flange 32 for fastening the sealing element 30 is welded to the outer wall 31 of the housing or its supporting structure.
• a sealing ring 34 On a support plate 33 of the trough 18, which forms a sealing surface, there is a sealing ring 34 which is inserted in a sealing ring support frame 35 and fastened there. Between the support flange 32 and the sealing ring support frame 35 there is a displacement element 37 for the sealing ring support frame 35, which allows a change in length and is formed by a bellows 36, which is fastened sealingly on the one hand to the support flange 32 and on the other hand to the sealing ring support frame 35.
• synchronously controllable shifting devices 38 which are formed by pressure medium cylinders 39, are arranged at several points, distributed over the circumference of the housing 13, with which the sealing ring 34 is connected to the support plate 33 of the collecting trough 18 in the closed position of the trough can be pressed or lifted from it if the trough is to be moved to its open position for emptying.
• fenders 40 which can be telescopically pushed into one another are fastened both on the support flange 32 and on the sealing ring support frame 35 between the bellows and the outer wall 31 of the housing 13.
• the sealing ring 34 is made of an elastic material such as fabric, fiber material and the like. But it can also be replaced by another type of seal, such as a sand seal, the support plate on the trough being designed as a trough-shaped receptacle for sand and instead of the sealing ring, a sealing plate is immersed in this sand fill in the closed position of the trough.
• the sealing plate is in turn adjustable in height with a displacement element, such as a pressure medium cylinder.
• FIGS. 3-5 analogously to FIG. 2, a further embodiment of the most efficient possible seal between the housing 13 and the collecting trough 18 arranged underneath it and the scrap collecting container 25 is shown.
• the sealing element 30, as described in relation to FIG. 2 providing a tight connection to the collecting trough 18 and the further sealing element 30a arranged concentrically with this sealing element 30 Connects to the scrap container 25.
• the construction of the two sealing elements 30, 30a is identical and corresponds to the explanations for FIG. 2. Any other sealing element with the same effect can be used in the same way. As a result of this double arrangement, a sealing connection always remains, either to the collecting trough 18 or to the scrap collecting container 25 on at least three sides during all operating cases.
• the trough 18 here is trough-shaped, double-walled and water-cooled and filled with sand.
• FIG. 3 illustrates an operating case as it occurs in the start-up phase of the casting process.
• the scrap trough 18 is moved into the open position, so that the housing 13 to the scrap collection container 25 is open and falling strip parts fall directly into the scrap collection container.
• the sealing element 30 encompassing the housing 13 on all sides rests with its sealing ring 34 on the support plate 33 of the scrap collecting container 25 and is in its deepest operating position and seals the gap between the housing and the scrap collecting container.
• FIG. 4 illustrates an operating case in which the collecting trough 18 assumes the closed position below the housing 13 and the sealing element 30 with its sealing ring 34 rests on the support plate 33 of the collecting trough 18. Any scrap and scale falling down are collected in the trough until the scrap collection container 25 returns to its receiving position below the closed trough after it has been emptied. During this closed position of the collection trough 18, the scrap collection container 25 can be operated without impairment of the production process on the two-roll casting system can be briefly driven out of the system at any time to empty it.
• FIG. 5 illustrates the operating case in which accumulated scrap is emptied from the collection trough 18 into the scrap collection container.
• the sealing element 30, which closes the gap between the housing 13 and the collecting trough 18 in an air-tight manner, is raised into a release position, the collecting trough 18 is brought into its open position by a transverse movement and, at the same time, scrap collected with the clearing sword 27 in the collecting trough is collected in the collecting trough Scrap container pushed.
• the sealing element 30 is placed on the scrap collection container. With a sealing element segmented along its circumferential extent, individual segments can be placed on the scrap collection container immediately after the collection trough has been moved away.
• the treatment chamber 14 immediately following on the transport path of the cast metal strip of the housing 13 can also be flooded with protective gas.
• the bottom of this treatment chamber 14 below the belt transport device 15 formed by a roller table, on which the still hot metal belt is transported is equipped with two emptied, funnel-shaped collecting containers 41 with closure flaps 43, which are opened by pressure medium cylinders 42 and can be closed.
• a scrap collecting container 25 equipped with a driving control can move to the emptying position below the closed collecting trough 18 as well as individual emptying positions below the closing flaps 43, which are opened after the respective emptying position has been assumed.
• the individual emptying positions are determined by sliding contacts or light barriers.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Continuous Casting (AREA)
• Processing Of Solid Wastes (AREA)
• Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Moulding By Coating Moulds (AREA)

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• 2003
  • 2003-05-06 AT AT0067803A patent/AT412539B/de not_active IP Right Cessation
• 2004
  • 2004-04-22 DE DE502004002305T patent/DE502004002305D1/de not_active Expired - Lifetime
  • 2004-04-22 CN CNB2004800124028A patent/CN100534668C/zh not_active Expired - Lifetime
  • 2004-04-22 US US10/555,564 patent/US7156150B2/en not_active Expired - Lifetime
  • 2004-04-22 EP EP04728773A patent/EP1620217B1/fr not_active Expired - Lifetime
  • 2004-04-22 MX MXPA05011789A patent/MXPA05011789A/es active IP Right Grant
  • 2004-04-22 WO PCT/EP2004/004264 patent/WO2004098814A1/fr active IP Right Grant
  • 2004-04-22 AT AT04728773T patent/ATE347951T1/de not_active IP Right Cessation
  • 2004-04-22 AU AU2004235896A patent/AU2004235896B2/en not_active Ceased
• 2005
  • 2005-11-04 KR KR1020057021053A patent/KR101209825B1/ko active IP Right Grant

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