CN202655586U - Continuous casting device for large-section hollow tube blank - Google Patents

Abstract

A continuous casting device for a large-section hollow pipe blank comprises an inner crystallizer, an outer crystallizer, an upper cover mechanism, a base mechanism, a circular-ring cylindrical dummy ingot device with a circular-ring-shaped section, a tundish with a heating function and a casting flow distributor; the interiors of the base mechanism and the upper cover mechanism are mutually communicated and fixed up and down; the outer crystallizer is fixed below the base mechanism; the inner crystallizer is of a columnar structure and is fixedly connected to the upper cover mechanism, the lower part of the inner crystallizer penetrates through the upper cover mechanism and the base mechanism, the lower part of the inner crystallizer is positioned at the inner side of the outer crystallizer and is concentrically surrounded by the outer crystallizer, the molten metal in the tundish is distributed into one stream or multiple streams by the casting flow distributor and is guided into the upper cover mechanism, and the molten metal is filled between the inner crystallizer and the outer crystallizer along a tangent line; in the initial casting stage, the annular cylinder dummy ingot device is arranged at the bottom of the annular cavity between the inner crystallizer and the outer crystallizer, molten metal is cooled by the inner crystallizer and the outer crystallizer to form a solidified hollow tube blank, and the hollow tube blank is positioned on the annular cylinder dummy ingot device.

Description

Continuous casting device for large-section hollow tube blank

Technical Field

The utility model relates to a large-section hollow pipe blank continuous casting device.

Background

Along with the development of industries such as petroleum, chemical industry, wind power, nuclear power and the like, the requirements of large-diameter tubular blanks, cylindrical blanks, annular blanks and large-section high-quality solid ingot blanks are continuously increased, the requirements of quality, efficiency and cost cannot be met by the traditional ingot casting forging and hole punching and hole expanding technology, along with the increase of the section diameter of a casting, the center is loose, the shrinkage cavity and segregation are worsened, the yield is low (50-65%), the production efficiency is low, and the like, and the development of the industry is severely restricted.

The continuous casting technology is influenced by large-section heat transfer, the internal quality and the production efficiency of a casting blank are obviously reduced along with the increase of the diameter of the section, and even if the liquid core soft reduction technology is further increased along with the diameter, the transmission of the deformation of the surface layer of the round blank to the center becomes weaker and weaker, so that the solid continuous casting blank with the diameter of more than 1000mm becomes a forbidden zone which is difficult to exceed in continuous casting.

The same is true for the continuous casting tube technology of large-section casting blanks, the continuous casting tube of the traditional mature technology mostly adopts a horizontal casting method, a central casting hole adopts a solid graphite rod with smaller draft angle, the diameter of the casting tube is usually not more than phi 500mm, and the wall thickness is also thinner not more than 100 mm. As the diameter increases, defects such as impurities, precipitated gases, segregation, etc. accumulate upward during solidification, and the quality is seriously deteriorated, thereby limiting the possibility of horizontal casting.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a large section hollow shell continuous casting device, it can be fit for the manufacturing of the hollow shell of big specification.

The above object of the present invention can be achieved by the following technical solutions:

a continuous casting device for a large-section hollow pipe blank comprises an inner crystallizer, an outer crystallizer, an upper cover mechanism, a base mechanism, a circular-ring cylindrical dummy ingot device with a circular-ring-shaped section, a tundish with a heating function and a casting flow distributor; the base mechanism is communicated with the inner part of the upper cover mechanism, and the upper cover mechanism is fixedly connected with the base mechanism up and down; the outer crystallizer is fixedly connected below the base mechanism; the inner crystallizer is of a columnar structure, the inner crystallizer is fixedly connected to the upper cover mechanism, the lower part of the inner crystallizer penetrates through the upper cover mechanism and the base mechanism, the lower part of the inner crystallizer is positioned at the inner side of the outer crystallizer and concentrically surrounded by the outer crystallizer, the molten metal in the tundish is distributed into one stream or multiple streams by the casting flow distributor and is guided into the upper cover mechanism, and the molten metal is filled between the inner crystallizer and the outer crystallizer; at the initial casting stage, the annular cylindrical dummy ingot device is arranged at the bottom of the annular cavity between the inner crystallizer and the outer crystallizer, the molten metal is cooled by the inner crystallizer and the outer crystallizer to form a solidified hollow tube blank, and the hollow tube blank is positioned on the annular cylindrical dummy ingot device.

The embodiment of the utility model provides a characteristics and advantage are: it adopts interior crystallizer and outer crystallizer to combine together, carries out two-way cooling to the casting blank, makes the casting blank cooling and solidifies adaptable effective section and wall thickness greatly increased to can be fit for the manufacturing of the hollow tube blank of big specification, in addition, the embodiment of the utility model provides a still can realize continuous and semicontinuous casting.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural section view of a large-section hollow shell continuous casting apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic view showing an assembly process of parts of a continuous casting machine of the large-section hollow shell continuous casting apparatus according to the embodiment of the present invention;

fig. 3 is a partially enlarged schematic view of a large-section hollow shell continuous casting apparatus according to an embodiment of the present invention for showing an outer mold;

fig. 4 is a partially enlarged schematic view of a large-section hollow shell continuous casting apparatus according to an embodiment of the present invention to show a second water cooling system;

FIG. 5 is a schematic structural view of an inner crystallizer of the large-section hollow shell continuous casting device according to the embodiment of the present invention;

FIG. 6 is a schematic view showing an assembly process of each part of an inner mold of a large-section hollow shell continuous casting apparatus according to an embodiment of the present invention;

fig. 7 is a schematic bottom view of an upper cover mechanism of a large-section hollow shell continuous casting apparatus according to an embodiment of the present invention;

FIG. 8 is A schematic sectional view taken along line A-O-A of FIG. 7;

fig. 9 is a schematic bottom view of a base mechanism of the large-section hollow shell continuous casting apparatus according to the embodiment of the present invention;

FIG. 10 is a schematic sectional view taken along line B-O-O1-B of FIG. 9;

fig. 11 is a schematic diagram of the simulation prediction result of the continuous casting defect of the ultra-large section hollow large-section casting blank of the large-section hollow shell continuous casting device according to the embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Implementation mode one

As shown in fig. 1 to 5, the embodiment of the present invention provides a continuous casting device for large-section hollow pipe blank, which includes an inner crystallizer 1, an outer crystallizer 2, an upper cover mechanism 5, a base mechanism 6, a ring cylindrical dummy ingot device 10 with a circular ring-shaped section, a tundish 7 with heating and a casting distributor 8. The inner parts of the upper cover mechanism 5 and the base mechanism 6 are mutually communicated, and the upper cover mechanism 5 and the base mechanism 6 are fixedly connected up and down to form an annular molten metal bath 3. The outer crystallizer 2 is fixedly connected below the base mechanism 6; the inner crystallizer 1 is of a columnar structure, the inner crystallizer 1 is fixedly connected to the upper cover mechanism 5, the lower portion of the inner crystallizer 1 penetrates through the upper cover mechanism 5 and the base mechanism 6, the lower portion of the inner crystallizer 1 is located on the inner side of the outer crystallizer 2 and is concentrically surrounded by the outer crystallizer 2, the molten metal in the tundish 7 is distributed into one stream or multiple streams by the casting flow distributor 8 and is guided into the upper cover mechanism 5, and the molten metal is filled between the inner crystallizer 1 and the outer crystallizer 2. At the initial casting stage, the annular cylinder dummy ingot device 10 is arranged at the bottom of the annular cavity between the inner crystallizer 1 and the outer crystallizer 2, the molten metal is cooled by the inner crystallizer 1 and the outer crystallizer 2 to form a solidified hollow tube blank 4, and the hollow tube blank 4 is positioned on the annular cylinder dummy ingot device 10.

In this embodiment, the lower part of the inner mold 1 is disposed at the center of the inner side of the outer mold 2, and the space between the inner mold 1 and the outer mold 2 is filled with the molten metal, that is, the molten metal is cooled bidirectionally by the two molds between the inner mold 1 and the outer mold 2, and is drawn out from below the two molds as a solidified hollow shell 4 after cooling. Further, in the embodiment, the inner crystallizer 1 is combined with the outer crystallizer 2, and the hollow pipe blank 4 is cooled in two directions, so that the effective thickness of the hollow pipe blank 4, which can be adapted to cooling and solidification, is greatly increased, and the method is suitable for manufacturing a large-size casting blank.

In this embodiment, the inner mold 1 and the outer mold 2 are fixedly connected together by the upper cover mechanism 5 and the base mechanism 6, so that the inner mold and the outer mold are fixed and concentrically arranged, and thus, the replacement of each component becomes easier and more convenient. In addition, the embodiment can produce large-diameter tube blanks with different wall thickness specifications by replacing different outer diameter sizes.

Referring to fig. 5, the inner mold 1 includes a water inlet straight conduit 1h, a water return conduit 1i and a cooling water circuit. The water return guide pipe 1i is arranged outside the water inlet straight guide pipe 1h at intervals in a surrounding mode, the water return guide pipe 1i comprises a water return straight guide pipe 1j and an inner crystallizer outer sleeve 1k which are connected up and down, the inner crystallizer outer sleeve 1k is in a column shape, and a first heat insulation sleeve 1g is wrapped outside the water return guide pipe 1 i; a cooling water circuit is provided inside the inner crystallizer 1. The cooling water loop comprises a water inlet loop 1a, a water return loop 1b and a water hole 1 c. The water inlet loop 1a is positioned in the water inlet straight conduit 1h, and the upper end of the water inlet loop 1a is provided with a water inlet 1 d; a gap between the water inlet straight conduit 1h and the water return conduit 1i forms the water return loop 1b, and the upper end of the water return loop 1b is provided with a water return port 1 e; the water hole 1c is arranged between the lower end of the water inlet straight conduit 1h and the inner crystallizer jacket 1k, and the water inlet loop 1a is communicated with the water return loop 1b through the water hole 1 c.

In this embodiment, the cooling water enters the water inlet circuit 1a from the water inlet 1d, then flows into the water return circuit 1b through the water holes 1c, and then flows out from the water return port 1 e. Wherein, the water inlet 1d and the water return port 1e are both positioned at the upper end of the inner crystallizer 1, the water hole is positioned at the lower end of the inner crystallizer 1, so that cooling water flows in the inner crystallizer 1, and the molten metal near the inner crystallizer 1 in the annular molten metal bath 3 can be fully cooled.

Further, the water return straight conduit 1j further comprises a water return flange 13a, the inner side end of the water return flange 13a is connected to the water inlet straight conduit 1h, and the outer side end is connected to the bottom of the water return straight conduit 1 j; the inner crystallizer outer sleeve 1k comprises an outer sleeve 13b and an outer sleeve flange 13c connected to the top of the outer sleeve 13b, and the inner side end of the outer sleeve flange 13c is connected to the water inlet straight conduit 1 h;

the inner crystallizer 1 further comprises an inner crystallizer inner sleeve 13d, the inner crystallizer inner sleeve 13d comprises an inner sleeve 13e and an inner sleeve upper flange 13f connected to the top of the inner sleeve 13e, the inner side end of the inner sleeve upper flange 13f is connected to the water inlet straight conduit 1h, and the inner sleeve 13e is arranged inside the outer sleeve 13b at intervals; the backwater flange 13a, the outer sleeve flange 13c and the inner sleeve upper flange 13f are fixedly connected together in sequence from top to bottom; the lower part of the inner sleeve 13e is also provided with a partition plate 13g and an inner sleeve end surface cover plate 13h, the inner sleeve end surface cover plate 13h is positioned below the partition plate 13g, the inner side ends of the partition plate 13g and the inner sleeve end surface cover plate 13h are connected to the water inlet straight conduit 1h, and the outer side ends of the partition plate 13g and the inner sleeve end surface cover plate 13h are connected to the inner sleeve 13 e;

the water hole includes first water hole 13i, second water hole 13j, third water hole 13k and fourth water hole 13m, first water hole 13i radially runs through the lower part of the straight pipe 1h of intaking, second water hole 13j radially runs through interior sleeve pipe 13 e's lower extreme, just first, two water holes 13i, 13j all are located between baffle 13g and the endotheca end cover board 13h, third water hole 13k radially runs through interior sleeve pipe 13 e's upper end, third water hole 13k is located baffle 13 g's top, fourth water hole 13m vertically runs through return water flange 13a, flange 13f on overcoat flange 13c and the endotheca.

In the present embodiment, as shown by the arrow direction in fig. 5, the cooling water enters the water inlet straight pipe 1h from the water inlet 1d, then enters the gap between the outer sleeve 13b and the inner sleeve 13e from the first and second water holes 13i, 13j, then enters the gap between the inner sleeve 13e and the water inlet straight pipe 1h from the third water hole 13k, then flows into the gap between the water return straight pipe 1m and the water inlet straight pipe 1h from the fourth water hole 13m, and then flows out from the water return port 1 e.

The first heat insulation sleeve 1g comprises a high-temperature fire-resistant pipe 1m and high-strength graphite 1n, the high-temperature fire-resistant pipe 1m is wrapped outside the water return straight conduit 1j, and the high-strength graphite 1n is wrapped outside the inner crystallizer outer sleeve 1 k. In the embodiment, the high-temperature refractory pipe 1m is arranged on the periphery of the water return straight conduit 1j to separate the external high-temperature overheated molten metal from the water return straight conduit 1j, the high-strength graphite 1n is arranged outside the inner crystallizer jacket 1k in a surrounding manner, and the inner crystallizer jacket 1k is separated from the molten metal to play a role in heat transfer and protection of the inner crystallizer.

An inner crystallizer flange 1f is arranged above the inner crystallizer 1, and the inner crystallizer 1 is fixed on the upper cover mechanism 5 through the inner crystallizer flange 1f, namely, the part of the inner crystallizer 1 below the position of the inner crystallizer flange 1f is positioned in the annular molten metal bath 3, and the part of the inner crystallizer flange 1f is positioned outside the annular molten metal bath 3.

Further, the backwater pipe 1i further comprises a backwater emitting pipe 1p, the backwater emitting pipe 1p is sleeved outside the water inlet straight pipe at intervals and is connected to the top of the backwater straight pipe 1j, a gap between the backwater emitting pipe and the water inlet straight pipe is communicated with the backwater loop, the backwater port 1e is arranged on the backwater emitting pipe 1p, and the inner crystallizer flange 1f is located at the top of the backwater straight pipe 1 j. Wherein, the backwater top pipe 1p can be directly connected with the backwater straight pipe 1j, such as welded; or, as shown in fig. 6, the lower end of the return water cap conduit 1p is connected with a return water cap flange 1q, the return water cap flange 1q is connected with the inner crystallizer flange 1f in a matching manner, and the return water cap conduit 1p is further connected with a return water straight conduit 1 j.

As shown in fig. 1 and fig. 3, the outer crystallizer 2 includes an outer crystallizer jacket 2a, an outer crystallizer inner jacket 2b and a crystallizer copper tube 2c, which are sequentially arranged from outside to inside at intervals, a transversely disposed isolation plate 2d is connected between the outer crystallizer inner jacket 2b and the outer crystallizer jacket 2a, the inner side end of the isolation plate 2d is connected with the outer crystallizer inner jacket 2b, the outer side end is connected with the outer crystallizer jacket 2a, and the isolation plate 2d can be located at the middle position of the outer crystallizer inner jacket 2b in the height direction; an electromagnetic stirrer 2e is arranged between the inner and outer jackets 2b and 2a of the outer crystallizer, and the electromagnetic stirrer 2e is positioned above the isolation plate 2 d; the outer crystallizer jacket 2a is respectively provided with a water inlet 2f and a water outlet 2g, the water inlet 2f is positioned below the isolation plate 2d, and the water outlet 2g is positioned above the isolation plate 2 d; the upper end and the lower end of the inner sleeve 2b of the outer crystallizer are respectively penetrated with a water flow hole 2 h; and a second heat insulation sleeve 2i is arranged at the joint of the outer crystallizer 2 and the casting blank 4, namely the second heat insulation sleeve 2i is positioned at the inner side of the outer crystallizer 2.

Wherein the outer mould 2 may be connected to the base means 6 by an outer mould flange 2j, where the outer mould flange 2j is connected to the top end of the mould copper tube 2c, the outer mould flange 2j being combined with a second base flange 6g for connecting the outer mould 2 to the base means 6. The second insulating sleeve 2i may be high strength graphite. The electromagnetic stirrer 2e is disposed in the outer mold 2, and can crush and stir crystal grains to form a large number of crystal nuclei.

In this embodiment, a gap is formed between the inner and outer jackets 2b, 2a of the outer crystallizer, and the partition plate 2d partitions the space between the inner and outer jackets 2b, 2a into two independent spaces; a gap is arranged between the outer crystallizer inner sleeve 2a and the crystallizer copper pipe 2 c. As shown by the arrow direction in fig. 4, the cooling water enters the lower gap between the inner and outer jackets 2b, 2a of the outer mold from the water inlet 2f, then flows into the gap between the inner jacket 2a of the outer mold and the copper tube 2c of the mold from the water flow hole 2h at the lower end of the inner jacket 2a of the outer mold, then flows into the upper gap between the inner and outer jackets 2b, 2a through the water flow hole 2h at the upper end of the inner jacket 2a of the outer mold, and then flows out from the water outlet 2 g. The cooling water flows in the outer crystallizer 2, exchanges heat with the molten metal in the outer crystallizer 2, and then flows out of the hot water outlet 2 g.

According to the embodiment of the present invention, as shown in fig. 7 and 8, the upper cover mechanism 5 includes an upper cover housing 5a in Jiong shape, and a first upper cover flange 5b is connected to the outside of the bottom of the upper cover housing 5a for connecting the base mechanism 6. And a heat insulation lining body 5c is built in the inner cavity of the upper cover shell body 5 a. An inner crystallizer through hole 5d is axially formed in the central shaft of the upper cover mechanism 5 in a penetrating manner, a water gap through hole 5e is axially formed in the upper cover mechanism 5 in a penetrating manner, the water gap through hole 5e is located on the outer side of the inner crystallizer through hole 5d, and a second upper cover flange 5f is arranged at the top of the upper cover shell 5a corresponding to the inner crystallizer through hole 5d and used for being connected with the inner crystallizer 1. In this embodiment, the inner mold 1 is fixed on the second upper cover flange 5f through the inner mold through hole 5d, so that the inner mold 1 and the upper cover mechanism 5 are combined together, the molten metal flows into the upper cover mechanism 5 through the water gap through hole 5e, and the water gap through hole 5e can be used for observing the liquid level. Here, two uniformly distributed water gap penetration holes 5e are provided around the inner mold penetration hole 5 d.

At the bottom of the heat-insulating and heat-preserving lining body 5c, a slag trap 5g is provided extending from the edge of the inner mold penetration hole 5d to the outside in the tangential direction, and the slag trap 5g separates molten metal distributed in the annular molten metal bath 3 from upper dross, and as shown in fig. 9, there are two slag traps 5 g. The upper cover mechanism 5 is axially provided with a dispersion hole 5h in a penetrating manner, the dispersion hole 5h is positioned outside the inner crystallizer perforation 5d, the upper part of the upper cover shell 5a is provided with a heat insulation cover plate 5i covering the upper end of the dispersion hole 5h, and the heat insulation cover plate 5i can prevent heat in the annular molten metal bath 3 from being dispersed from the dispersion hole 5 h. Here, two diffusing holes 5h are uniformly distributed around the inner mold penetration hole 5d, the diffusing holes 5h are used for discharging gas generated and brought in the cavity of the annular molten metal bath 3 at the initial casting stage and during casting, and the diffusing holes can also be used as observation and temperature measuring holes and the like.

As shown in fig. 8, the heat insulation and preservation lining body 5c includes a refractory ramming material 5j and a heat insulation refractory lining 5k, the heat insulation refractory lining 5k is connected to the bottom of the inner cavity of the upper cover shell 5a, and the refractory ramming material 5j is filled between the upper cover shell 5a and the heat insulation refractory lining 5 k. After the inner mold 1 is inserted into the inner mold through hole 5d, the refractory ramming material 5j and the heat-insulating refractory lining 5k respectively surround the inner mold 1 at the upper cover mechanism 5 in the vertical position.

As shown in fig. 9 and 10, the base mechanism 6 includes a base housing 6a in a shape of a Chinese character 'ao', a first base flange 6b for connecting the cover mechanism is connected to the top outer side of the base housing, and the first base flange is fixedly combined with the first cover flange 5b through a fastening connector, such as a combination of a flange bolt 5m and a flange nut 6j, to fixedly connect the cover mechanism 5 and the base mechanism 6 together. A refractory lining body 6c is arranged on the base shell 6a, a base center hole 6d is arranged in the center axial direction of the base mechanism 6 in a penetrating mode, and a second base flange 6g used for being connected with the outer crystallizer 2 is arranged at the position, corresponding to the base center hole 6d, of the bottom of the base shell 6 a.

The upper part of the base mechanism 6 is provided with a tangent ingate 6h which is tangentially arranged with the central hole of the base, the outer end of the tangent ingate corresponds to the water gap penetrating hole 5e, and the inner end of the tangent ingate is communicated with the central hole 6d of the base.

And a variable frequency induction coil 6e is annularly arranged at the lower part of the base mechanism and positioned at the upper part of the outer crystallizer, the variable frequency induction coil is annularly arranged at the outer side of the central hole 6d of the base, and a coil protection cover 6f is arranged outside the variable frequency induction coil 6 e. Wherein, the variable frequency induction coil 6e and the molten metal can be separated by a refractory lining body 6 c. In the normal throwing process, the variable frequency induction coil 6e adopts the functions of low frequency auxiliary stirring, primary crystal grain crushing, internal and external temperature homogenization and outward heat transfer, and transmits a nucleation core to the core part, and adopts power frequency or intermediate frequency for heating and heat preservation of residual molten steel in the later stage of throwing. In addition, a magnetic magnetizer 6p may be further enclosed outside the variable frequency induction coil 6e and inside the coil protecting cover 6 f.

The base mechanism 6 is axially provided with a slag discharge port 3a corresponding to the dispersion hole 5h, and a slag discharge groove 6i is connected between the slag discharge port and the base center hole 6 d. Here, there are two evenly distributed tangential ingates 6h and two evenly distributed gutters 6 i.

In this embodiment, the molten metal entering the upper cover mechanism 5 enters the base mechanism 6 through the tangent ingate 6h, the tangent ingate 6h changes the molten metal from the vertical direction to the tangential direction of the annular cavity, and then moves circumferentially along the annular cavity, and the liquid slag floating above the molten metal is stopped by the slag baffle 5g on the upper cover mechanism 5 in the process of rotating along with the molten metal and flows out of the slag discharge port 3a along the slag discharge groove 6 i.

In addition, as shown in fig. 1 and 2, the base mechanism 6 may be mounted on the steel structure foundation 3b, and a slag storage tray 3c may be placed on the steel structure foundation 3b at a position corresponding to the slag discharge port 3a, so that the dross discharged from the slag discharge port 3a falls into the slag storage tray 3 c.

The refractory lining body 6c includes a high temperature refractory lining 6k, a carbon refractory lining 6m and a knotted refractory 6n, the high temperature refractory lining 6k is provided at an upper portion of an inner cavity of the base housing 6a, the carbon refractory lining 6m is provided at a lower portion of the high temperature refractory lining 6k and is located around the base center hole 6d, and the knotted refractory 6n is filled between the high temperature refractory lining 6k and the base housing 6a and is located outside the coil protecting cover 6 f. That is, in this embodiment, the high temperature refractory lining 6k and the carbon refractory lining 6m are both in contact with the high temperature molten metal, the lower end of the carbon refractory lining 6m is adjacent to the outer mold 2, and the variable frequency induction coil 6e is disposed on the periphery of the carbon refractory lining 6m and protected by the coil protection cover 6 f; the high-temperature refractory lining 6k and the carbon refractory brick lining 6m constitute a base inner layer working lining, and a knotted refractory 6n is filled between the base shell 6a and the base inner layer working lining.

As shown in fig. 5, the casting apparatus further includes a second water cooling system 9, the second water cooling system 9 is connected below the outer mold 2, and the second water cooling system 9 includes an outer two-water-cooling spray assembly 9a, a two-cold-section foot roller 9e and an inner two-water-cooling spray assembly 9 f. The outer two-water-cooling spraying assembly 9a comprises a plurality of rows of outer two-water-cooling nozzle ring groups 9b arranged along the axial direction of the casting blank 4, each row of outer two-water-cooling nozzle ring group 9b is provided with a plurality of outer two-water-cooling nozzles 9c uniformly distributed along the outer circumference of the casting blank, and a steam recovery box 9d is arranged outside the outer two-water-cooling spraying assembly 9 a. The double-cooling-section foot roller 9e is arranged between two outer two water-cooling nozzle ring groups 9b which are adjacent up and down, so that water flow sprayed by the outer two water-cooling nozzles 9c is sprayed to the casting blank 4 as much as possible and is not blocked by the double-cooling-section foot roller 9e, and the double-cooling-section foot roller 9e can be used for clamping the red hot casting blank 4 with a liquid core. The inner two water-cooling spraying assembly 9f comprises a central water spraying pipe 9g and a plurality of rows of inner two water-cooling nozzle groups 9j arranged along the axial direction of the central water spraying pipe, the central water spraying pipe 9g is connected with a nozzle guide pipe 9i inserted in the water inlet straight guide pipe 1h through the reducing joint 9h, the upper end of the nozzle guide pipe 9i penetrates out of the water inlet straight guide pipe 1h to be exposed, and the lower end of the nozzle guide pipe is positioned in the water inlet straight guide pipe 1 h. Wherein, the upper and lower positions of each inner two water-cooling nozzle set 9j and each outer two water-cooling nozzle set 9b can correspond.

In addition, the central water spraying pipe 9g can be communicated with the nozzle guide pipe 9i, and the upper end of the nozzle guide pipe 9i is provided with a water quantity control switch 9k for controlling the water spraying quantity of the inner two water-cooling nozzle groups 9 j; or, the nozzle conduit 9i is rotatably arranged, the bottom end of the nozzle conduit 9i is provided with a valve, when the inner two water-cooling nozzle groups 9j are required to spray water, the valve is opened to enable the water of the nozzle conduit 9i to flow into the central water spraying pipe 9g, when the inner two water-cooling nozzle groups 9j are not required to spray water, the valve is closed, and the water of the nozzle conduit 9i cannot flow into the central water spraying pipe 9 g.

The inner two water-cooled spray assemblies 9f of this embodiment are used to continue cooling the inner walls of the hollow cast blank 4 of the inner and outer molds 1, 2.

In this embodiment, the outer two water-cooling spray nozzles 9c of the outer two water-cooling spray assembly 9a are used for continuously cooling the outer surface of the casting slab of the mold, the outer two water-cooling spray assembly 9a includes six rows of outer two water-cooling spray nozzle ring sets 9b arranged along the length direction of the casting slab 4, the figure is only schematic, the number of the spray nozzles in the nozzle view cooling length may be 5 to 50 rows, each outer two water-cooling spray nozzle ring set 9b has a plurality of outer two water-cooling spray nozzles 9c, the number of the outer two water-cooling spray nozzles 9c may be determined according to the requirement and the diameter of the casting slab 4, and here, each outer two water-cooling spray nozzle ring set 9b has 6 to 12 outer two water-cooling spray nozzles.

As shown in fig. 1, the tundish 7 can be a tundish which is heated by electromagnetic heating, and the bottom of the tundish 7 is provided with a tapping hole; the top of the casting flow distributor 8 is provided with a molten steel receiving port, 1 to 4 shunt pipes 8a can be uniformly distributed at the lower part of the casting flow distributor 8, the number of the shunt pipes 8a is the same as that of water gap penetrating holes 5e of the upper cover mechanism 5, and two shunt pipes 8a are arranged at the position, namely, the casting flow distributor 8 distributes water flow in the tundish 7 into two flows which are symmetrical 180 degrees and are guided into the upper cover mechanism 5; of course, the flow distributor 8 may also distribute the flow of water in the tundish 7 into one flow, three flows, or more flows, and introduce the flow into the cover mechanism 5, as necessary.

A plurality of rows of clamping guide rollers 12 are annularly arranged below the outer crystallizer 2 and are used for clamping the red hot casting blank 4 with the liquid core from the inner crystallizer 1 and the outer crystallizer 2.

The casting device further comprises a lifting push rod 11, wherein the lifting push rod 11 is connected to the bottom of the circular cylindrical dummy ingot device 10 and drives the circular cylindrical dummy ingot device 10 to move up and down. In this embodiment, in the initial casting stage, the bottom of the annular cavity below the inner and outer crystallizers 1 and 2 is sealed by the annular cylinder dummy ingot device 10, and as casting progresses, the lifting push rod 11 drags the annular cylinder dummy ingot device 10 downward and vibrates periodically up and down, so that the casting blank shell moves up and down relative to the inner and outer crystallizers 1 and 2, and the purpose of shelling the casting blank shell and the inner and outer crystallizers 1 and 2 is achieved.

Besides, the casting blank shell respectively makes up-and-down relative motion with the inner crystallizer 1 and the outer crystallizer 2, besides the lifting push rod 11 drives the circular ring cylinder dummy ingot device 10 to move up and down, the method also comprises the following steps:

a blank drawing mechanism is arranged on the circular ring cylindrical dummy ingot device 10, the blank drawing mechanism drives the circular ring cylindrical dummy ingot device 10 to move up and down, and the upper inner crystallizer 1 and the upper outer crystallizer 2, the base mechanism 6 and the upper cover mechanism 5 are not moved; or,

a hydraulic vibration mechanism is arranged between the steel structure foundations 3b, and the base mechanism 6 and the inner and outer crystallizers 1 and 2 are dragged by the hydraulic vibration mechanism to perform vertical periodic motion.

The blank drawing mechanism and the hydraulic vibration mechanism are well known to those skilled in the art and will not be described herein.

Fig. 11 shows the result of the simulation defect prediction analysis of an actual case of the present invention, and the experimental scheme is semi-continuous casting of hollow shell of container steel with outer diameter phi 1800mm, wall thickness 500mm, height 11000mm, inner hole diameter phi 1000mm and test material Q345R. As shown in fig. 11, the test results: the casting yield of the casting blank is more than 90%; the center has no shrinkage cavity defects; the center has slight porosity-like defects that can be forged and rolled. When the length of the drawing billet is 20000mm, continuous casting can be realized, and the casting yield of the casting billet can reach 95-98 percent.

As shown in fig. 1, the following describes the operation of the embodiment of the present invention:

(1) assembling: as shown in fig. 2 and 6, the assembly of each component is completed, the dummy ingot device 10 is arranged in the annular cavity below the inner crystallizer 1 and the outer crystallizer 2, and the peripheral gap is processed, so that the casting of the material can be carried out;

(2) casting: the qualified molten steel is hung above a tundish 7, a molten steel ladle water gap control system is opened, a liquid outlet of the tundish 7 is opened after the molten steel amount in the tundish 7 reaches 80%, the molten steel is respectively led into water gap penetrating holes 5e of upper cover mechanisms 5 which are 180 degrees from each other from a molten steel outlet of the tundish 7 through a casting flow distributor 8, then the molten steel rotates to enter a round billet casting cavity of a base mechanism 6 through a tangent inner pouring gate 6h, the molten metal makes circular motion in the casting cavity, dross floating on the molten metal surface realizes steel-slag separation through specific gravity difference in the rotating process, is separated by a slag baffle 5g arranged on the upper cover mechanism 5 to enter a slag discharge groove 6i, and is discharged from a slag discharge port 3 a;

the molten metal is cooled and solidified by the inner crystallizer 1 and the outer crystallizer 2 to form a blank shell, the blank shell is pulled downwards by the dummy ingot device 10, and simultaneously, the lifting push rod 11 drives the dummy ingot device and the casting blank to vibrate up and down relative to the crystallizers 1 and 2, so that the blank shell is separated from the crystallizers, the blank shell gradually moves downwards at the blank pulling speed, meanwhile, the effective section and the wall thickness are gradually increased, and solidified blank shells and core liquid cores along the two sides of the inner crystallizer 1 and the outer crystallizer 2 are formed in the crystallizers; when the shell is pulled out of the inner crystallizer and the outer crystallizer, the red hot shell is exposed in the air and enters a second water cooling system 9;

(3) and (3) cooling control: the outer surface of the red hot large-section tube blank with the liquid core entering the second water cooling system 9 is cooled by the outer two water cooling nozzles 9c from the lower part of the outer crystallizer 2, the inner surface of the red hot large-section tube blank is cooled by the inner two water cooling nozzles, the temperature is gradually reduced, and the proportion of the liquid core is gradually reduced until the bottom of the V-shaped tube blank is completely formed into a solid;

(4) electromagnetic stirring and heating stop pouring: after the superheated molten metal is injected into the cavity, a weak solidified layer or a supercooled metal layer is formed on the inner cavity of the cylindrical surface under the cooling temperature reduction of the cooling water loops on the inner crystallizer 1 and the outer crystallizer 2 and the variable frequency induction coil 6 e;

in the normal casting process, the variable-frequency induction coil 6e mainly uses a periodic low-frequency alternating magnetic field to stir the supercooled metal layer, and mixes the supercooled molten metal with the liquid with higher temperature in the middle of the liquid to increase the number of non-uniform cores in the molten metal; in the later stage of casting, the pulling speed is gradually reduced in a matching manner until the pulling is stopped, when feeding liquid above the feeding liquid is only used for supplementing the part which is identical to the feeder head and is needed by solidification of the V-shaped liquid core, the working frequency of the variable-frequency induction coil 6e is changed into power frequency or medium frequency continuous power supply, and at the moment, the water-cooling variable-frequency induction coil 6e serves as an induction heating holding furnace to play a role in holding and heating the feeder head;

then, with the continuous reduction of the liquid core, when the tail end of the liquid core gradually enters the crystallizer, the cooling water in the inner crystallizer 1 is gradually reduced, the inner crystallizer 1 is slowly lifted until the residual metal liquid in the variable frequency induction coil 6e completely enters the blank shell, the inner crystallizer 1 is completely pulled out, and a heat insulation material is covered above the residual metal liquid until the residual metal liquid is completely solidified;

(5) stripping ingots: taking out the solidified steel billet from the casting system through a hot moment in the normal continuous casting process at the lower end of the complete solidification zone to realize continuous casting blank; after the continuous casting is performed for a certain length, the casting may be stopped until the remaining molten metal is completely solidified (the casting stop step in (4) above), and finally the entire ingot blank may be taken out at once to realize a semicontinuous cast slab.

The embodiment of the utility model provides a compare with traditional approach and have following advantage:

1. because the embodiment of the utility model provides an adopt the special fixed mode of upper cover mechanism 5, base mechanism 6 and crystallizer 1 in the center, make the fixed of inside and outside crystallizer 1, 2, change with one heart and become more easy convenient.

2. Because the embodiment of the utility model provides an adopt inside and outside crystallizer 1, 2 to the two-way cooling of casting blank, make the casting blank cooling, solidify adaptable effective thickness greatly increased, the casting blank thickness bodiness that can cast is nearly one time.

3. Because the utility model discloses the pipe casting system has adopted the second water cooling system of inside and outside water spray, and the traditional mechanism cooling strength of single surface water spray relatively is high, and casting blank liquid core is short, the product density is high, the segregation is light, of high quality.

4. Because the embodiment of the utility model provides an adopt vertical casting throwing method, it is inconsistent to have avoided the solidification from top to bottom of big section circumference, and impurity or segregation have guaranteed the uniformity of whole casting blank quality at the not enough of the first half gathering.

5. Because the embodiment of the utility model provides a casting system has adopted two tangent line formula ingate structures, and the molten metal is followed the tangent line and is watered the rotatory die cavity that gets into of 6h, has avoided the especially very large section cast temperature of whole section, has solidified inconsistent phenomenon, still utilizes the slag proportion difference to separate the slag effect simultaneously.

6. Because the embodiment of the utility model provides a set up sediment indisputable separation baffle mechanism on the rotatory orbit of upper cover metal liquid, have slag trap 5g promptly, separation, the discharge that can effectual realization dross and pure metal liquid.

7. Because the embodiment of the utility model provides an inside and outside crystallizer 1, 2 all adopted the compound work lining of high strength graphite, can effectually play the effect of protection copper sheathing crystallizer, have lubricated shelling auxiliary efficiency, can realize not having the casting of covering slag.

8. Because the embodiment of the utility model provides a set up frequency conversion induction coil 6e, realized the beneficial effect of normal production process electromagnetic stirring, refine crystalline grain, adjustment intracavity metal liquid temperature, cooperation tail billet drawing speed's change has played the heating of tail billet rising head simultaneously and has kept warm, shortens tail billet shrinkage cavity, draw, improves the important effect of casting blank lumber recovery.

In conclusion, owing to the application of above measure, make the utility model discloses super large diameter, the hollow shell continuous casting of thick wall can be realized, and the effect that improves the foundry goods quality, improves the lumber recovery has been played to the second water cooling system and the semi-solid phase tamping method of inside and outside crystallizer cooling system, inside and outside surface water spray, frequency conversion induction coil tail base heating heat preservation effect.

The above description is only for the embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention according to the disclosure of the application document without departing from the spirit and scope of the present invention.

Claims (15)

1. A continuous casting device for a large-section hollow pipe blank is characterized by comprising an inner crystallizer (1), an outer crystallizer (2), an upper cover mechanism (5), a base mechanism (6), a circular-ring cylindrical dummy ingot device (10) with a circular-ring-shaped section, a tundish (7) with a heating function and a casting flow distributor (8); the base mechanism (6) is communicated with the inside of the upper cover mechanism (5), and the upper cover mechanism is fixedly connected with the base mechanism up and down; the outer crystallizer is fixedly connected below the base mechanism; the inner crystallizer (1) is of a columnar structure, the inner crystallizer (1) is fixedly connected to the upper cover mechanism (5), the lower part of the inner crystallizer penetrates through the upper cover mechanism and the base mechanism, the lower part of the inner crystallizer (1) is located on the inner side of the outer crystallizer and is concentrically arranged by the outer crystallizer (2), the molten metal in the tundish (7) is distributed into one stream or multiple streams by the cast stream distributor (8) and is led into the upper cover mechanism (5), and the molten metal is filled between the inner crystallizer (1) and the outer crystallizer (2); at the initial casting stage, the annular cylindrical dummy ingot device (10) is arranged at the bottom of the annular cavity between the inner crystallizer and the outer crystallizer, the molten metal is cooled by the inner crystallizer and the outer crystallizer to form a solidified hollow tube blank (4), and the hollow tube blank is positioned on the annular cylindrical dummy ingot device.

2. The continuous casting device of a large-section hollow shell according to claim 1, characterized in that the inner crystallizer (1) comprises a water inlet straight conduit (1h), a water return conduit and a cooling water loop; the water return guide pipe is arranged outside the water inlet straight guide pipe in a surrounding mode at intervals and comprises a water return straight guide pipe and an inner crystallizer outer sleeve which are connected up and down, the inner crystallizer outer sleeve is in a column shape, and a first heat insulation sleeve is wrapped outside the water return guide pipe; the cooling water loop is arranged inside the inner crystallizer; the cooling water loop comprises a water inlet loop (1a), a water return loop (1b) and a water hole (1 c); the water inlet loop (1a) is positioned in the water inlet straight conduit, and the upper end of the water inlet loop is provided with a water inlet (1 d); a gap between the water inlet straight conduit and the water return conduit (1i) forms the water return loop (1b), and the upper end of the water return loop (1b) is provided with a water return port (1 e); the water hole (1c) is arranged between the lower end of the water inlet straight conduit (1h) and the inner crystallizer jacket (1k), and the water inlet loop (1a) is communicated with the water return loop (1b) through the water hole (1 c).

3. The continuous casting device of a large-section hollow shell according to claim 2, characterized in that the first heat insulating sleeve (1g) comprises a high-temperature fire-resistant pipe (1m) and high-strength graphite (1n), the high-temperature fire-resistant pipe is wrapped outside the water return straight conduit (1j), and the high-strength graphite is wrapped outside the inner crystallizer jacket (1 k).

4. The continuous casting device for large-cross-section hollow shell according to claim 2, characterized in that an inner mold flange (1f) is arranged above the inner mold, and the inner mold (1) is fixed on the upper cover mechanism (5) through the inner mold flange;

the backwater guide pipe (1i) further comprises a backwater emitting guide pipe (1p), the backwater emitting guide pipe is sleeved outside the water inlet straight guide pipe at intervals and is connected to the top of the backwater straight guide pipe (1j), a gap between the backwater emitting guide pipe and the water inlet straight guide pipe is communicated with the backwater loop, the backwater port (1e) is arranged on the backwater emitting guide pipe, and the inner crystallizer flange (1f) is located at the top of the backwater straight guide pipe (1 j).

5. The continuous casting device of the large-section hollow pipe blank according to claim 2, wherein the water return straight conduit (1j) further comprises a water return flange (13a), the inner side end of the water return flange is connected to the water inlet straight conduit (1h), and the outer side end of the water return flange is connected to the bottom of the water return straight conduit; the inner crystallizer outer sleeve (1k) comprises an outer sleeve (13b) and an outer sleeve flange (13c) connected to the top of the outer sleeve, and the inner side end of the outer sleeve flange is connected to the water inlet straight conduit;

the inner crystallizer (1) further comprises an inner crystallizer inner sleeve (13d), the inner crystallizer inner sleeve comprises an inner sleeve (13e) and an inner sleeve upper flange (13f) connected to the top of the inner sleeve, the inner side end of the inner sleeve upper flange is connected to the water inlet straight conduit (1h), and the inner sleeve is arranged inside the outer sleeve at intervals; the backwater flange (13a), the outer sleeve flange (13c) and the inner sleeve upper flange are fixedly connected together in sequence from top to bottom; the lower part of the inner sleeve (13e) is also provided with a partition plate (13g) and an inner sleeve end surface cover plate (13h), the inner sleeve end surface cover plate is positioned below the partition plate, the inner side ends of the partition plate and the inner sleeve end surface cover plate are connected to the water inlet straight conduit (1h), and the outer side ends of the partition plate and the inner sleeve end surface cover plate are connected to the inner sleeve;

the water hole includes first water hole (13i), second water hole (13j), third water hole (13k) and fourth water hole (13m), first water hole radially runs through the lower part of the straight pipe of intaking (1h), the second water hole radially runs through the lower extreme of interior sleeve pipe (13e), just first, two water holes all are located between baffle (13g) and the endotheca end cover board (13h), the third water hole radially runs through the upper end of interior sleeve pipe (13e), the third water hole is located the top of baffle (13g), the fourth water hole vertically runs through return water flange (13a), flange (13f) on overcoat flange and the endotheca.

6. The continuous casting device of the large-section hollow shell as claimed in claim 1, wherein the upper cover mechanism (5) comprises an Jiong-shaped upper cover shell (5a), a first upper cover flange (5b) used for connecting the base mechanism (6) is connected to the outer side of the bottom of the upper cover shell, and a heat insulation lining body (5c) is built in the inner cavity of the upper cover shell; an inner crystallizer through hole (5d) is formed in the central shaft of the upper cover mechanism in an axially penetrating mode, a water gap through hole (5e) is formed in the upper cover mechanism in an axially penetrating mode and is located on the outer side of the inner crystallizer through hole (5d), and a second upper cover flange (5f) used for being connected with the inner crystallizer (1) is arranged on the top of the upper cover shell (5a) corresponding to the position of the inner crystallizer through hole.

7. The continuous casting apparatus of a large-cross-section hollow shell according to claim 6, wherein a slag trap (5g) is provided at the bottom of the heat-insulating and heat-retaining lining body (5c) so as to extend tangentially outward from the edge of the inner mold penetration hole (5 d); a dispersion hole (5h) axially penetrates through the upper cover mechanism (5), the dispersion hole is positioned at the outer side of the inner crystallizer perforation (5d), and a heat insulation cover plate (5i) covering the upper end of the dispersion hole is arranged at the upper part of the upper cover shell (5 a);

the heat-insulation and heat-preservation lining body (5c) comprises a refractory ramming material (5j) and a heat-insulation refractory lining (5k), the heat-insulation refractory lining is connected to the bottom of the inner cavity of the upper cover shell (5a), and the refractory ramming material (5j) is filled between the upper cover shell and the heat-insulation refractory lining.

8. The continuous casting device for the large-section hollow shell as claimed in claim 1, wherein the base mechanism (6) comprises a concave base shell (6a), a first base flange (6b) used for connecting the upper cover mechanism is connected to the outer side of the top of the base shell, the first base flange is fixedly combined with the first upper cover flange (5b) through a fastening connector, a refractory lining body (6c) is arranged on the base shell, a central axial direction of the base mechanism is provided with a base center hole (6d) in a penetrating mode, and a second base flange (6g) used for connecting the outer crystallizer (2) is arranged at the bottom of the base shell (6a) corresponding to the position of the base center hole.

9. The continuous casting device for the large-section hollow shell as claimed in claim 8, wherein the upper part of the base mechanism (6) is provided with a tangent ingate (6h) which is tangentially arranged with the central hole of the base, the outer end of the tangent ingate corresponds to the water gap through hole (5e), and the inner end of the tangent ingate is communicated with the central hole (6d) of the base.

10. The continuous casting apparatus for large-diameter hollow shell according to claim 8, wherein the lower part of the base mechanism is provided with a variable frequency induction coil (6e) at the upper part of the outer mold, the variable frequency induction coil surrounds the outer side of the center hole of the base, and a coil protecting cover (6f) is provided outside the variable frequency induction coil.

11. A large-section hollow shell continuous casting device according to claim 8, characterized in that a slag discharge port (3a) is axially arranged on the base mechanism (6), the slag discharge port corresponds to the dispersion hole (5h), and a slag discharge groove (6i) is connected between the slag discharge port and the base center hole (6 d).

12. The continuous casting apparatus for large-diameter hollow shell as claimed in claim 10, wherein the refractory lining body (6c) comprises a high temperature refractory lining (6k) provided at an upper portion of the inner cavity of the base shell (6a), a carbon refractory brick lining (6m) provided at a lower portion of the high temperature refractory lining and located around the base center hole (6d), and a knotting refractory (6n) filled between the high temperature refractory lining and the base shell and located outside the coil protecting cover (6 f).

13. The continuous casting device of the large-section hollow shell as claimed in claim 2, wherein the casting device further comprises a second water cooling system (9) connected below the outer crystallizer, and the second water cooling system comprises an outer second water-cooling injection assembly (9a), an inner second water-cooling injection assembly (9f) and a second cold-section foot roll (9 e); the outer two-water-cooling spraying assembly comprises a plurality of rows of outer two-water-cooling nozzle ring groups (9b) which are axially arranged along the casting blank (4), each row of outer two-water-cooling nozzle ring group is provided with a plurality of outer two-water-cooling nozzles (9c) which are uniformly distributed along the outer circumference of the casting blank, and a steam recovery box (9d) is arranged outside the outer two-water-cooling spraying assembly; the inner two water-cooling spraying assembly (9f) comprises a central water spraying pipe (9g) and a plurality of rows of inner two water-cooling nozzle groups (9j) which are arranged along the axial direction of the central water spraying pipe, the central water spraying pipe is connected with a nozzle guide pipe (9i) inserted in the water inlet straight guide pipe (1h) through a reducing joint (9h), the upper end of the nozzle guide pipe (9i) penetrates out of the water inlet straight guide pipe to be exposed, and the lower end of the nozzle guide pipe is positioned in the water inlet straight guide pipe; the two-cold-section foot roll (9e) is arranged between the two outer two water-cooling nozzle ring groups which are adjacent up and down and is used for clamping the red hot casting blank (4) with the liquid core.

14. A large-section hollow shell continuous casting device according to claim 1, characterized in that the casting device further comprises a lifting push rod (11) which is connected to the bottom of the annular cylindrical dummy ingot device (10) and drives the dummy ingot device to move up and down.

15. A large-section hollow shell continuous casting apparatus as claimed in claim 1, wherein a plurality of rows of pinch guide rolls (12) are provided annularly below the outer mold (2).

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