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
  • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
• • 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
  • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
  • B22D11/053—Means for oscillating the moulds

Definitions

• the invention relates to a sealing element for sealing an annular gap between a vibrating pouring tube and a stationary housing component of a continuous casting mold.
• the invention also relates to a continuous casting mold with at least one such sealing element.
• a classic vibrating device comprises a vibrating table on which the continuous casting mold is arranged as a unit.
• a mold which has a fixed housing with an integrated rocker arm.
• the pouring tube is carried in this mold by the rocker arm and is connected to an outer, fixed housing via two elastically deformable, annular sealing membranes in such a way that it can vibrate in the housing along the pouring axis.
• the annular sealing membranes seal an annular pressure chamber for a cooling liquid around the pouring tube.
• Patent application WO 95/03904 proposes both metallic and rubber-elastic ring membranes. These ring membranes are subject to extremely complex mechanical stresses. First, you have to endure a cooling water pressure of at least 5 bar, which already leads to significant tensile stresses in the ring membrane. They are also vibration loads with a frequency of several hundred Vibrations per minute exposed, the vertical stroke movements of the pouring tube cause large tensile stress peaks in the ring membrane. Furthermore, the strand can exert horizontal tensile forces on the pouring tube, which can stress the ring membrane. Under these complex loads, signs of fatigue on the ring membranes can be expected relatively quickly.
• the object of the present application is to create an improved sealing element for sealing an annular gap between a vibrating pouring tube and a stationary housing component of a continuous casting mold from a flexible material.
• the sealing element forms a circumferential bulge whose convex side is arranged on the pressure side when the sealing element is mounted.
• the sealing element according to the invention is structurally much more suitable for absorbing the extremely complex mechanical stresses in the continuous casting mold than the previously known flat sealing membranes. It shows signs of fatigue less quickly, which in turn results in a longer lifespan.
• This technical success can be explained approximately as follows. With an axial movement of the pouring tube relative to the stationary housing component, a deformation of the sealing element is determined, which essentially consists in a flattening of the bulge.
• the sealing element according to the invention is thereby stretched much less than the known flat ring membranes and is consequently subject to lower tensile stresses. Furthermore, the pressure acts on the convex side of the circumferential bulge of the sealing element and consequently essentially generates compressive stresses in this sealing element and no tensile stresses.
• the sealing element according to the invention is advantageously designed as a ring membrane which is installed horizontally in the continuous casting mold.
• the material of the ring membrane does not experience any radial or circumferential direction when the pouring tube moves axially. an essential extension.
• the sealing element according to the invention could also be designed as a pipe socket, which is installed coaxially to the casting axis in the continuous casting mold. In the design as a pipe socket, however, the material of the sealing element is slightly stretched in the region of the bulge in the circumferential direction.
• the sealing element according to the invention is advantageously made of a rubber-elastic material, such as an elastomer or rubber. It advantageously comprises reinforcing inserts, for example fabric inserts. In the embodiment as a pipe socket, such fabric inserts should have interruptions in the circumferential direction in order to take into account the extent in the circumferential direction.
• the invention also relates to a continuous casting mold which comprises a vibrating pouring tube, a stationary housing and at least one flexible sealing element for sealing an annular pressure chamber for a cooling liquid between the vibrating pouring tube and the stationary housing.
• this flexible sealing element forms a circumferential bulge, the convex side of which faces the annular pressure chamber.
• Such a mold advantageously comprises a vibrating device and a fixed support structure, the support structure carrying the vibrating device and the vibrating device carrying the pouring tube.
• the weight of the pouring tube is absorbed by the vibrating device and the sealing elements are no longer loaded by the weight of the pouring tube.
• No additional support elements need to be arranged between the housing and the pouring tube.
• a compact oscillating device is designed with an oscillating lever which is articulated in the support structure and is articulated to the pouring tube.
• This oscillating device advantageously comprises a hydraulic cylinder as the drive.
• the pouring tube could also be elastically suspended in its housing by means of spring elements, so that the vibrating device does not have to perform a supporting function and only the vibration energy has to be transferred to the pouring tube.
• the invention proposes several solutions as to how the sealing elements according to the invention can advantageously be arranged in a continuous casting mold.
• the mold has a lower and upper sealing element according to the invention, which delimit an annular pressure chamber for a cooling liquid around the entire pouring tube.
• This annular pressure chamber is advantageously divided by an inner sealing device with a rubber-elastic ring membrane into a lower and upper annular collector, which are connected to an inlet line or a return line for a cooling liquid.
• a water guiding jacket is advantageously arranged around the pouring tube in such a way that it forms an annular gap along the pouring tube, which on the one hand opens into the lower collector and on the other hand into the upper collector.
• the mold has a lower and upper flexible ring collector, which surrounds the lower and upper end of the pouring tube, these flexible ring collectors each comprising two directly opposite sealing elements according to the invention, which are arranged such that they are between one another define an annular pressure chamber for a coolant.
• the cooling water content of the mold is reduced in this second embodiment.
• an electromagnetic stirring device outside the cooling water can be arranged between the lower and upper flexible ring collector.
• a water guiding jacket can be arranged around the pouring tube in such a way that it forms an annular gap along the pouring tube, which on the one hand opens into the lower flexible ring collector and on the other hand into the upper flexible ring collector.
• This Wasserleitman ⁇ tel is then formed between the ring collectors as a pressure jacket.
• Casting tube act, at least one guide element between the vibrating pouring tube and the fixed housing be arranged such that there is a lateral pivoting of the pouring tube after at least a first Direction limited.
• This guide element is advantageously connected to the vibrating pouring tube or the fixed housing via at least one swivel joint.
• this swivel joint can have, for example, a horizontal play which allows the guide element to be displaced horizontally in a second direction, which is opposite to the first direction.
• the guide element can also be mounted in at least one swivel joint in an elastically compressible sleeve or can be designed telescopically.
• a leaf spring which is installed essentially horizontally and is firmly clamped on one side, is also a possible solution as a guide element.
• FIG. 1 shows a schematic longitudinal section through a mold with two sealing elements according to the invention
• FIG. 2 shows a schematic longitudinal section through a mold with four sealing elements according to the invention
• Figure 3 in an enlarged detail of Figure 1, a section through the sealing element according to the invention and a guide element;
• FIGS. 4-6 possible embodiments for fastening a sealing element according to the invention
• FIGS. 7-9 possible designs of a swivel joint for a guide element
• Figure 10 a plan view of an alternative embodiment of a guide element.
• FIG. 1 shows a first embodiment of a mold for a continuous caster.
• the mold comprises a pouring tube 10 which has a pouring channel 12 for the liquid
• This pouring tube 10 comprises, for example, a one-piece copper tube 12 made of pure copper or a copper alloy, which is attached to is provided at its lower end with a lower flange 16 and at its upper end with an upper flange 18.
• Vertical struts 20 connect the lower flange 16 to the upper flange 18 and give the pouring tube additional rigidity.
• the pouring tube 10 can of course also comprise individual shaped plates instead of the one-piece copper tube 12. These shaped plates are then held together by a frame construction in order to form the pouring tube.
• the mold can of course be designed to cast a wide variety of products, such as billets, pre-profiles (beam blanks), slabs, thin slabs, etc.
• the pouring tube 10 is surrounded by an outer cooling box 22, which has a lower frame 24 and an upper frame 26.
• This cooling box 22 is carried by a stationary support structure, which is indicated in FIG. 1 by the supports 28, for example.
• the pouring tube 10 is in this case carried by a rocker arm 30 which is connected to the fixed cooling box 24 via a cylindrical swivel joint 32.
• a second cylindrical swivel joint 34 connects the pouring tube 10 to the free end of the rocker arm 30.
• the other end of the rocker arm 30 is connected, for example, to a hydraulic cylinder which generates vibrations with a stroke of a few millimeters and with a frequency of a few Hertz. These vibrations are transmitted to the pouring tube 10 via the lever 30.
• the lower flange 16 of the pouring tube 10 is connected to the lower frame 24 of the cooling box 22 by means of a first flexible sealing element 36 according to the invention.
• the upper flange 18 of the pouring tube 10 is connected to the upper frame 26 of the cooling box 22 by means of a second sealing element 38 according to the invention.
• An annular chamber is accordingly axially sealed around the pouring tube 10 by the two sealing elements 36, 38 according to the invention, the pouring tube 10 being able to oscillate freely in the cooling box 22 along the pouring axis.
• the two sealing elements 36, 38 according to the invention consist of a flexible material, preferably a rubber-elastic material Fabric inserts.
• Each of the sealing elements 36, 38 forms an annular membrane, the outer edge of which is clamped in the upper or lower frame 26, 24 of the cooling box 22, and the inner edge of which is clamped in the upper or lower flange 18, 16 of the pouring tube 10 .
• the lower membrane 36 is described on the basis of FIG. 3, representative of all other membranes.
• the membrane 36 forms a circumferential bulge 40, the convex side of which faces the annular pressure chamber.
• An essentially flat ring body 42, 44 flows smoothly on both sides of this circumferential bulge 40.
• the wall thickness of the membrane and the reinforcing inserts are designed such that the circumferential bulge 40 keeps its convex bulge in the direction of the pressure chamber even after the annular pressure chamber has been pressurized.
• the membrane 36 assumes the shape indicated by broken lines. It is found that the deformation of the membrane consists essentially of a flattening of the bulge 40, that is to say a change in the radii of curvature. It should be noted that the material of the membrane 36, during an axial movement of the pouring tube 10, is not substantially stretched neither in the radial nor in the circumferential direction, that is to say that the stroke movements do not result in any significant tensile stresses in the membrane.
• the pressure in the annular pressure chamber acts on the convex side of the circumferential bulge 40 of the sealing element 36 and essentially generates compressive stresses in this sealing element 36.
• This prestressing of the sealing element 36 has a positive effect on the vibration stress of the sealing element, since it counteracts the remaining tensile stresses that arise during the oscillation process and thus reduces the tensile stress peak values in the material of the sealing element.
• the membrane 36 has an annular bead 24, 44 with a round cross-section both on its inner and on its outer edge.
• This annular bead 24, 44 is by means of a Fastening flange 16 ', or 24', in an annular groove of the flange 16 on the pouring tube, or in an annular groove of the frame 24 on the cooling box 22, fitted and clamped.
• the annular bead 44 ' has a substantially rectangular cross-section with two concave, circumferential indentations in which one bead of the frame 24 or of the fastening flange 24' engages.
• the reference number 48 shows a through hole for a bolt in the bead 44 '. If the annular bead 44 'is relatively flat in FIG. 4, the annular bead 44 "in FIG. 6 has a greater height than width. As shown in FIG.
• the membrane 36 is advantageously spanned with at least one guide element 50.
• This guide element 50 transmits horizontal forces, which are exerted by the strand on the pouring tube 10, from the pouring tube 10 via the lower frame 24 to the supporting frame 28 (see FIG. 1).
• FIG 51, or 52 connected to the flange 16, or the frame 24.
• the joint 52 not only allows the guide element 50 to be rotated about the joint axis “O” but also to move the guide element 50 to the right by the amount "x", where:
• L length of the guide element 50
• ymax maximum stroke (positive or negative).
• the guide element 50 does not provide any substantial resistance to the vertical stroke movements of the pouring tube 10.
• the lifting movements of the pouring tube 10 cause neither tensile stresses nor bending stresses in the guide element 50.
• the guide element 50 works exclusively in the direction of the arrow 44 and is under compressive stress.
• the guide element 50 in FIG. 3 thus prevents the pouring tube 10 from moving in the direction of the arrow 54.
• a second guide element 56 (see Figure 1), which on the opposite Side of the pouring tube 10 is arranged, prevents the pouring tube 10 from moving in the opposite direction of the arrow 54.
• Further guide elements can, for example, be arranged in a plane perpendicular to the drawing.
• FIG. 8 corresponds to the design of the joint in FIG. 7, only one sliding sleeve 58 being provided for the cylindrical articulation pin 60 of the guide element 50.
• Figure 9 relates to an alternative embodiment of the joint of a guide element 50.
• two lateral bearing journals 60 are each equipped with an elastically compressible sleeve 62, for example made of rubber, and are each fitted into a bearing bore in a fastening tab 64.
• the elastically compressible sleeve 62 ensures that the guide element 50 'does not oppose any substantial resistance to the vertical stroke movements of the pouring tube 10.
• the guide element 50 can also be designed as a spring element (for example as a leaf spring). One end of the spring element is to be clamped rigidly and the second end is to be mounted in a joint corresponding to FIG. 7, 8 or 9. In this embodiment, the lifting movements of the pouring tube 10 in the spring element cause bending stresses, but no tensile stresses.
• the guide elements 50 can also be designed as a telescopic rod, with blocking means limiting the axial collapse of the telescopic rod. Although good guidance is ensured by the lever 30 at the upper end of the mold, guide elements can of course also be arranged between the upper flange 18 and the upper frame 26.
• This guide element 50 is designed as a metallic, spring-elastic ring membrane with radial, wedge-shaped openings 150.
• the guide element 50 has an outer ring flange 152 and an inner ring flange 154, which are connected to one another via spring-elastic webs 156 are connected.
• the outer ring flange 152 is clamped in the frame 24.
• the inner ring flange 154 is clamped in the flange 16 of the pouring tube 10.
• the reference number 70 denotes a sealing device which divides the annular chamber between the pouring tube 10 and the cooling box 22 into an upper collector 72 and a lower collector 74, while allowing the pouring tube 10 to move freely in the cooling box 22.
• This sealing device 70 advantageously comprises an inner ring plate 76 on the pouring tube 10 and an outer ring plate 78 on the cooling box 22, which are connected by means of an annular, flexible sealing membrane 80.
• This annular, flexible sealing membrane 80 advantageously has a circumferential bulge which is designed such that its convex side faces the collector in which the pressure is highest (in FIG. 1 this is the lower collector 74).
• the lower collector 74 is supplied with cooling water via an inlet line 82.
• This cooling water flows through an annular inlet slot 84 into an annular gap 86, which is formed by a water-conducting jacket 88 around the pipe 14.
• the cooling water flows into the upper collector 46 via an annular return slot 90 and finally leaves the mold via a return line 92.
• Ring lines 116, 118 with spray nozzles are arranged on the outside below or above the ring membranes 36, 38. The latter spray the side of the ring membranes 36, 38 facing away from the pressure chamber with a cooling liquid.
• FIG. 2 shows an embodiment of a mold for a continuous casting installation with four ring membranes 100, 102, 104 and 106 according to the invention.
• This embodiment differs from the embodiment of FIG. 1 essentially in that the upper and lower collectors 72, 74 of FIG flexible ring collectors 72 ', 74' each with two stacked ring membrane NEN 100, 102 and 104, 106 are formed. These ring membranes 100, 102 and 104, 106 are formed and fastened as described above.
• the actual cooling box 22 is therefore omitted in the mold according to FIG. 2.
• the pouring tube 10 is only surrounded by a supporting structure 108 in which the pouring tube 10 is suspended and the two pairs of ring plates 110, 112 and 114, 116 for connecting the ring membranes 100, 102 and 104, 106.
• the ring plates of each pair 110, 112 and 114, 116 are each connected to one another via an outer pressure jacket 111, or 115.
• Ring plate pair 110, 112 and pressure jacket 11 form an outer fixed boundary of the lower ring collector 74 '.
• Ring plate pair 1 14, 116 and pressure jacket 115 form an outer fixed boundary of the upper ring collector 72 '.
• Support brackets 118 connect the outer fixed boundary of the upper ring collector 72 'with that of the lower ring collector 72' and create axial space between the ring collectors 72 ', 74' for an electromagnetic stirring device 200. It should be noted that between the ring collectors 72 ', 74' of the water jacket 88 'is of course designed as a pressure jacket, since it has to withstand the cooling water pressure here. As in FIG. 1, the ring membranes 100 and 106 are also spanned with guide elements, and ring lines 120, 122, 124 and 126 are arranged with spray nozzles above and below the ring membranes 100, 102, 104 and 106.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Pipe Accessories (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Sealing Devices (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19731573

Family Applications (1)

Country Status (12)

Cited By (1)

Citations (7)

• 1996
  • 1996-01-18 LU LU88701A patent/LU88701A1/de unknown
  • 1996-12-12 CZ CZ982235A patent/CZ223598A3/cs unknown
  • 1996-12-12 JP JP09525621A patent/JP2000515069A/ja active Pending
  • 1996-12-12 EP EP96943925A patent/EP0874702A1/de not_active Withdrawn
  • 1996-12-12 PL PL96328240A patent/PL328240A1/xx unknown
  • 1996-12-12 TR TR1998/01364T patent/TR199801364T2/xx unknown
  • 1996-12-12 BR BR9612441A patent/BR9612441A/pt not_active Application Discontinuation
  • 1996-12-12 AU AU13705/97A patent/AU1370597A/en not_active Abandoned
  • 1996-12-12 KR KR1019980705462A patent/KR19990077316A/ko not_active Application Discontinuation
  • 1996-12-12 WO PCT/EP1996/005549 patent/WO1997026098A1/de not_active Application Discontinuation
  • 1996-12-23 TW TW085115881A patent/TW369445B/zh active
• 1998
  • 1998-07-17 NO NO983321A patent/NO983321D0/no not_active Application Discontinuation

Patent Citations (7)

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