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

Large-section hollow billet continuous casting device

technical field

The utility model relates to a continuous casting device for a large-section hollow billet.

Background technique

With the development of petroleum, chemical, wind power, nuclear power and other industries, the demand for large-diameter tubular billets, cylindrical billets, ring billets, and large-section high-quality solid ingot billets continues to increase, which cannot be met by traditional ingot forging punching and hole expansion technologies. The demand for quality, efficiency, and cost, along with the increase of casting section diameter, central looseness, shrinkage cavity, segregation deterioration, low yield (50-65%), and low production efficiency seriously restrict the development of this industry.

In continuous casting technology, due to the influence of large cross-section heat transfer, the internal quality and production efficiency of the billet also decrease significantly with the increase of the cross-section diameter. The transmission of deformation to the center becomes weaker and weaker, so that the solid continuous casting slab with a diameter of more than 1000mm has become an insurmountable forbidden zone for continuous casting.

The same is true for the continuous casting pipe technology of large cross-section casting slabs. The continuous casting pipe of traditional mature technology mostly adopts the horizontal casting method, and the central casting hole adopts a solid graphite rod with a small draft angle. The wall thickness is also thinner and does not exceed 100mm. As the diameter increases, impurities such as solidification process impurities, precipitated gases, and segregation accumulate upward, and the quality will seriously deteriorate, thus limiting the possibility of horizontal casting.

Utility model content

The purpose of the utility model is to provide a large-section hollow billet continuous casting device, which is suitable for the manufacture of large-sized hollow billets.

Above-mentioned purpose of the utility model can adopt following technical scheme to realize:

A large-section hollow billet continuous casting device, the casting device includes an inner mold, an outer mold, an upper cover mechanism, a base mechanism, a circular cylindrical dummy with a circular section, and a heated intermediate ladle and strand distributor; the base mechanism and the inside of the upper cover mechanism communicate with each other, and the upper cover mechanism and the base mechanism are fixedly connected up and down; the outer mold is fixedly connected below the base mechanism; the inner mold is Columnar structure, the inner crystallizer is fixedly connected to the upper cover mechanism, and the lower part of the inner crystallizer is penetrated inside the upper cover mechanism and the base mechanism, so that the lower part of the inner crystallizer is located in the outer crystallizer The inner side of the mold is arranged concentrically around the outer mold. The strand distributor distributes the molten metal in the tundish into one or more streams and guides it into the upper cover mechanism. Between the inner mold and the outer mold The gap is filled with molten metal; at the initial stage of pouring, the circular cylindrical dummy is set at the bottom of the annular cavity between the inner and outer molds, and the molten metal is cooled by the inner and outer molds A solidified hollow shell is formed which rests on a circular cylindrical dummy.

The characteristics and advantages of the embodiment of the utility model are: it adopts the combination of the inner crystallizer and the outer molder to cool the slab in two directions, so that the effective section and wall thickness that can be adapted to the cooling and solidification of the slab are greatly increased, so that it can be suitable for In addition, the embodiment of the utility model can also realize continuous and semi-continuous casting.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention. For example, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is a structural cross-sectional schematic diagram of a large-section hollow billet continuous casting device according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of the assembly process of the continuous casting machine parts of the large-section hollow billet continuous casting device of the embodiment of the present invention;

Fig. 3 is a partial enlarged schematic diagram of the large-section hollow billet continuous casting device for displaying the outer mold of the utility model embodiment;

Fig. 4 is a partially enlarged schematic diagram showing the second water cooling system of the large-section hollow billet continuous casting device of the embodiment of the present invention;

Fig. 5 is a schematic structural view of the inner crystallizer of the large-section hollow billet continuous casting device of the embodiment of the present invention;

Fig. 6 is a schematic diagram of the assembly process of each part of the inner mold of the large-section hollow billet continuous casting device according to the embodiment of the present invention;

Fig. 7 is a schematic bottom view of the upper cover mechanism of the large-section hollow billet continuous casting device according to the embodiment of the present invention;

Fig. 8 is a schematic cross-sectional view along the A-O-A line of Fig. 7;

Fig. 9 is a schematic bottom view of the base mechanism of the large-section hollow billet continuous casting device according to the embodiment of the present invention;

Fig. 10 is a schematic cross-sectional view along the line B-O-O1-B of Fig. 9;

Fig. 11 is a schematic diagram of the simulation prediction results of continuous casting defects of the super-large-section hollow large-section billet of the large-section hollow billet continuous casting device of the embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Implementation Mode 1

As shown in Figures 1 to 5, the large-section hollow billet continuous casting device proposed by the embodiment of the present invention includes an inner mold 1, an outer mold 2, an upper cover mechanism 5, and a base mechanism 6, and the section is circular. An annular cylindrical dummy 10 with a heated tundish 7 and a strand distributor 8 . The insides of the upper cover mechanism 5 and the base mechanism 6 communicate with each other, and the upper cover mechanism 5 and the base mechanism 6 are fixedly connected up and down to form an annular molten metal pool 3 . The outer crystallizer 2 is fixedly connected below the base mechanism 6; the inner crystallizer 1 is a columnar structure, and the inner crystallizer 1 is fixedly connected to the upper cover mechanism 5, and the lower part of the inner crystallizer 1 It penetrates inside the upper cover mechanism 5 and the base mechanism 6, so that the lower part of the inner mold 1 is located inside the outer mold 2, and is concentrically surrounded by the outer mold 2, and the casting strand The distributor 8 distributes the molten metal in the tundish 7 into one or more streams and guides it into the upper cover mechanism 5, and the space between the inner mold 1 and the outer mold 2 is filled with molten metal. At the initial stage of casting, the circular cylindrical dummy 10 is arranged at the bottom of the annular cavity between the inner and outer crystallizers 1, 2, and the molten metal passes through the inner and outer molds 1, 2 Cooling forms a solidified hollow shell 4 , which is positioned on a circular cylindrical dummy 10 .

In this embodiment, the lower part of the inner mold 1 is set 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 molten metal, that is, the inner mold 1 and the outer mold. Two-way cooling is implemented between the two crystallizers, and after cooling, the solidified hollow shell 4 is pulled out from the bottom of the two crystallizers. Furthermore, this embodiment uses the combination of the inner mold 1 and the outer mold 2 to cool the hollow shell 4 in two directions, so that the effective thickness of the hollow shell 4 to be cooled and solidified can be greatly increased, so that it can be suitable for larger molds. Manufacture of slabs to specifications.

In this embodiment, the above-mentioned inner crystallizer 1 and outer crystallizer 2 are fixedly connected together through the upper cover mechanism 5 and the base mechanism 6, so that the inner and outer crystallizers are fixed and concentrically arranged, so that the replacement of each part become easier and more convenient. In addition, in this embodiment, large-diameter tube blanks with different wall thickness specifications can be produced by replacing different outer diameters.

Referring to Fig. 5, the inner crystallizer 1 includes a water inlet straight conduit 1h, a return water conduit 1i and a cooling water circuit. The return water conduit 1i is arranged at intervals outside the straight water inlet conduit 1h. The return water conduit 1i includes a return water straight conduit 1j connected up and down and an inner crystallizer jacket 1k. The inner crystallizer jacket 1k is cylindrical. The outside of the return water conduit 1i is covered with a first heat insulation jacket 1g; the cooling water circuit is arranged inside the inner crystallizer 1 . The cooling water circuit includes a water inlet circuit 1a, a return water circuit 1b and a water hole 1c. The water inlet circuit 1a is located in the water inlet straight conduit 1h, and the upper end of the water inlet circuit 1a is the water inlet 1d; the gap between the water inlet straight conduit 1h and the return water conduit 1i constitutes the return water circuit 1b, the upper end of the return water circuit 1b is the water return port 1e; the water hole 1c is arranged between the lower end of the water inlet straight conduit 1h and the inner crystallizer jacket 1k, the water inlet circuit 1a and the return water The circuit 1b is connected through the water hole 1c.

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

Further, the straight water return pipe 1j also includes a water return flange 13a, the inner end of the water return flange 13a is connected to the straight water inlet pipe 1h, and the outer end is connected to the bottom of the straight water return pipe 1j; The inner crystallizer outer casing 1k includes an outer casing 13b and an outer casing flange 13c connected to the top of the outer casing 13b, and the inner side end of the outer casing flange 13c is connected to the straight water inlet conduit 1h;

The inner crystallizer 1 also includes an inner mold inner sleeve 13d, and the inner mold inner sleeve 13d includes an inner sleeve 13e and an inner sleeve upper flange 13f connected to the top of the inner sleeve 13e, and the inner sleeve upper flange 13f The inner end of the inner side is connected to the water inlet straight conduit 1h, and the inner casing 13e is arranged at intervals inside the outer casing 13b; the return water flange 13a, the outer casing flange 13c and the inner casing upper flange 13f are fixedly connected together up and down in turn; the lower part of the inner casing 13e is also provided with a partition 13g and an inner sleeve end cover 13h, the inner sleeve end cover 13h is located below the partition 13g, the partition 13g, the inner sleeve The inner end of the end cover plate 13h is connected to the water inlet straight conduit 1h, and the outer end is connected to the inner casing 13e;

The water holes include a first water hole 13i, a second water hole 13j, a third water hole 13k and a fourth water hole 13m, and the first water hole 13i radially penetrates the lower part of the water inlet straight conduit 1h, so The second water hole 13j radially penetrates the lower end of the inner casing 13e, and the first and second water holes 13i, 13j are both located between the partition plate 13g and the inner casing end cover plate 13h, the second Three water holes 13k radially penetrate the upper end of the inner casing 13e, the third water hole 13k is located above the partition plate 13g, the fourth water hole 13m runs through the return water flange 13a longitudinally, and the outer flange 13c and inner sleeve upper flange 13f.

In this embodiment, as shown in the direction of the arrow in Figure 5, the cooling water enters the water inlet straight conduit 1h from the water inlet 1d, and then enters between the outer casing 13b and the inner casing 13e from the first and second water holes 13i, 13j Then enter the gap between the inner casing 13e and the water inlet straight conduit 1h from the third water hole 13k, and then flow into the gap between the return water straight conduit 1m and the water inlet straight conduit 1h from the fourth water hole 13m The gap, and then flow out from the return port 1e.

The first heat insulation jacket 1g includes a high-temperature refractory pipe 1m and a high-strength graphite 1n, the high-temperature refractory pipe 1m is coated on the outside of the return water straight conduit 1j, and the high-strength graphite 1n is coated on the inner crystal The exterior of the device jacket 1k. In this embodiment, a high-temperature refractory pipe 1m is arranged on the periphery of the return water straight conduit 1j to separate the external high-temperature superheated metal liquid from the return water straight conduit 1j, and the high-strength graphite 1n is surrounded by the outer shell 1k of the inner mold to separate the inner mold The jacket 1k is separated from the molten metal to transfer heat while protecting the inner mold.

The top of the inner crystallizer 1 has an inner mold flange 1f, and the inner mold 1 is fixed on the upper cover mechanism 5 through the inner mold flange 1f, that is, in the inner mold 1 The part below the position of the inner mold flange 1f is in the annular molten metal pool 3 , and the part above the position of the inner mold flange 1f is outside the annular molten metal pool 3 .

Further, the return water conduit 1i also includes a return water riser conduit 1p, and the return water riser conduit 1p is sheathed on the outside of the water inlet straight conduit at intervals and connected to the top of the return water straight conduit 1j, The gap between the water return pipe and the water inlet straight pipe is connected with the return water circuit, the water return port 1e is arranged on the water return pipe 1p, and the inner crystallizer flange 1f is located on the return water circuit. Water straight to the top of conduit 1j. Wherein, the return water conduit 1p can be directly connected with the return straight conduit 1j, such as welding; or, as shown in Figure 6, the lower end of the return conduit 1p is connected to the return flange 1q, and the return method The blue 1q is connected with the flange 1f of the inner crystallizer, so that the return water conduit 1p is connected with the return water straight conduit 1j.

As shown in Figures 1 and 3, the outer mold 2 includes an outer mold outer jacket 2a, an outer mold inner jacket 2b, and a mold copper tube 2c arranged at intervals from outside to inside, and the outer mold inner jacket 2b and the outer crystallizer jacket 2a are connected with a laterally placed isolation plate 2d, the inner end of the isolation plate 2d is connected to the outer mold inner sleeve 2b, and the outer end is connected to the outer crystallizer outer sleeve 2a, and the isolation plate 2d can be located in the outer crystallizer. The inner cover 2b of the device is in the middle position in the height direction; there is an electromagnetic stirrer 2e in the outer crystallizer and between the outer jacket 2b and 2a, and the electromagnetic stirrer 2e is located above the separation plate 2d; the outer crystallizer A water inlet 2f and a water outlet 2g are respectively provided on the outer casing 2a of the device, the water inlet 2f is located below the isolation plate 2d, and the water outlet 2g is located above the isolation plate 2d; Water flow holes 2h pass through the lower ends respectively; a second heat insulation sleeve 2i is provided at the joint between the outer mold 2 and the casting slab 4 , that is, the second heat insulation sleeve 2i is located inside the outer mold 2 .

Wherein, the outer mold 2 can be connected to the base mechanism 6 through the outer mold flange 2j, where the outer mold flange 2j is connected to the top of the mold copper pipe 2c, and the outer mold The flange 2j is combined with the second base flange 6g to connect the outer crystallizer 2 to the base mechanism 6 . The second heat insulation sleeve 2i can be high-strength graphite. The electromagnetic stirrer 2e is arranged in the external crystallizer 2, and can crush and stir the crystal grains to form a large number of crystal nuclei.

In the present embodiment, there is a gap between the inner and outer jackets 2b and 2a of the outer crystallizer, and the separation plate 2d separates the interval between the inner and outer jackets 2b and 2a into two independent spaces up and down; There is a gap between the device copper pipes 2c. As shown in the direction of the arrow in Figure 4, the cooling water enters the outer crystallizer from the water inlet 2f and in the gap below between the outer jacket 2b and 2a, and then flows into the outer crystallizer from the water flow hole 2h at the lower end of the outer crystallizer 2a The gap between the inner sleeve 2a and the crystallizer copper tube 2c 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 outer crystallizer 2a, and then flows out from the water outlet 2g. Cooling water flows in the outer crystallizer 2, and after heat exchange with the molten metal inside the outer crystallizer 2, hot water flows out from the water outlet 2g.

According to the embodiment of the present utility model, as shown in Fig. 7 and Fig. 8, the upper cover mechanism 5 includes an upper cover casing 5a in a shape, and a first upper cover is connected to the outside of the bottom of the upper cover casing 5a. The flange 5b is used to connect the base mechanism 6 . The inner cavity of the upper cover shell 5a is built with a thermal insulation liner 5c. The center of the upper cover mechanism 5 is axially provided with an inner crystallizer perforation 5d, and the upper cover mechanism 5 is axially provided with a nozzle penetration hole 5e, and the nozzle penetration hole 5e is located in the inner crystallizer. On the outside of the through hole 5d, the top of the upper cover shell 5a is provided with a second upper cover flange 5f at the position corresponding to the inner crystallizer through hole 5d for connecting the inner mold 1 . In this embodiment, the inner crystallizer 1 passes through the hole 5d of the inner mold and is fixed on the second upper cover flange 5f, so that the inner mold 1 and the upper cover mechanism 5 are combined together, and the molten metal passes through the nozzle hole 5e Flow in the loam cake mechanism 5, meanwhile, the water mouth penetrates the hole 5e and can be used for observing the situation of the liquid level. Here, two evenly distributed nozzle penetration holes 5e are provided around the inner crystallizer perforation 5d.

At the bottom of the thermal insulation liner 5c, a slag retaining plate 5g is extended from the edge of the inner crystallizer perforation 5d to the outside along the tangential direction, and the slag retaining plate 5g will distribute the metal in the annular molten metal pool 3 The liquid is separated from the upper layer of scum, as shown in Figure 9, where there are two slag retaining plates 5g. The upper cover mechanism 5 is provided with a release hole 5h in the axial direction, and the release hole 5h is located outside the inner crystallizer perforation 5d. The heat insulating cover plate 5i of 5h upper end, the heat insulating cover plate 5i can prevent the heat in the annular molten metal pool 3 from diffusing from the release hole 5h. Here, two evenly distributed release holes 5h are arranged around the perforation 5d of the inner mold, and the release holes 5h are used to discharge the gas generated and brought into the cavity of the annular molten metal pool 3 during the initial stage of casting and during the casting process. , In addition, the diffusion hole can also be used as an observation, temperature measurement hole, etc.

As shown in Fig. 8, the heat insulating lining 5c includes a refractory knotting material 5j and a heat insulating and refractory lining 5k, and the heat insulating and refractory lining 5k is connected to the bottom of the inner cavity of the upper cover shell 5a, the The refractory knotting material 5j is filled between the upper cover shell 5a and the heat-insulating refractory lining 5k. When the inner crystallizer 1 is inserted into the inner mold perforation 5d, the refractory knotting material 5j and the heat-insulating refractory inner lining 5k surround the position of the inner mold 1 in the upper cover mechanism 5 respectively in the upper and lower positions.

As shown in Figures 9 and 10, the base mechanism 6 includes a recessed base housing 6a, and the top outside of the base housing is connected with a first base method for connecting the upper cover mechanism. flange 6b, the first base flange and the first upper cover flange 5b are fixedly combined by fastening connectors, and then the upper cover mechanism 5 and the base mechanism 6 are fixedly connected together, wherein the fastening connection The parts can be, for example, a combination of flange bolts 5m and flange nuts 6j. The base shell 6a is provided with a refractory lining 6c, the central axis of the base mechanism 6 is provided with a base center hole 6d, and the bottom of the base shell 6a corresponds to the base center hole 6d. The position is provided with a second base flange 6g for connecting the outer crystallizer 2 .

The upper part of the base mechanism 6 is provided with a tangential inrunner 6h arranged tangentially to the central hole of the base. The outer end of the tangential inrunner corresponds to the above-mentioned nozzle penetration hole 5e, and the inner end corresponds to the above-mentioned nozzle penetration hole 5e. The central hole 6d of the base is connected.

The lower part of the base mechanism is located on the upper part of the outer crystallizer and is provided with a frequency conversion induction coil 6e. The frequency conversion induction coil surrounds the outside of the base center hole 6d, and a coil protection cover 6f is provided outside the frequency conversion induction coil 6e. Wherein, the frequency conversion induction coil 6e and the molten metal can be separated by a refractory lining 6c. In the normal casting process, the frequency conversion induction coil 6e uses low frequency to assist stirring, break the primary grains, homogenize the internal and external temperature and transfer heat to the outside, and transfer the nucleation core to the core. Frequency or intermediate frequency, used for heating and heat preservation of the remaining molten steel. In addition, an avalanche permeable magnet 6p can be arranged outside the frequency conversion induction coil 6e and inside the coil protective cover 6f.

The base mechanism 6 is axially provided with a slag discharge port 3a, which corresponds to the above-mentioned release hole 5h, and a slag discharge ditch is connected between the slag discharge port and the central hole 6d of the base 6i. Here, there are two evenly distributed tangential inrunners 6h, and two evenly distributed slag discharge grooves 6i.

In this embodiment, the molten metal entering the upper cover mechanism 5 enters the base mechanism 6 from the tangential ingate 6h, and the tangential ingate 6h changes the molten metal from the vertical direction to the tangential direction along the annular cavity, and then along the annular cavity The body makes a circular motion, and the liquid slag floating above the molten metal is blocked by the slag retaining plate 5g on the upper cover mechanism 5 during the rotation with the molten metal, and flows out of the slag discharge port 3a along the slag discharge ditch 6i.

In addition, as shown in Figures 1 and 2, during installation, the base mechanism 6 can be installed on the steel structure foundation 3b, and the slag storage tray 3c can be placed on the steel structure foundation 3b corresponding to the slag discharge port 3a, The scum discharged from the slag outlet 3a falls into the slag storage pan 3c.

The refractory lining 6c includes a high-temperature refractory lining 6k, a carbon refractory brick lining 6m and a knotted refractory material 6n. The high-temperature refractory lining 6k is arranged on the upper part of the inner cavity of the base shell 6a. The plain refractory brick lining 6m is arranged at the lower part of the high-temperature refractory lining 6k and is located around the center hole 6d of the base, and the knotted refractory material 6n is filled between the high-temperature refractory lining 6k and the base shell 6a , and located outside the coil protection cover 6f. That is to say, in this embodiment, both the high-temperature refractory lining 6k and the carbon refractory brick lining 6m are in contact with the high-temperature molten metal, the lower end of the carbon refractory brick lining 6m is adjacent to the outer mold 2, and the frequency conversion induction coil 6e is set It is placed on the periphery of the carbon refractory brick lining 6m, and is protected by the coil protective cover 6f; the high-temperature refractory lining 6k and the carbon refractory brick lining 6m constitute the inner working lining of the base, and the base shell 6a works with the inner layer of the base. The interlining is filled with knotted refractory material 6n.

As shown in Figure 5, the casting device also includes a second water-cooling system 9, the second water-cooling system 9 is connected below the outer crystallizer 2, the second water-cooling system 9 includes two outer water-cooling injection assemblies 9a, two The cold segment foot roller 9e and the inner two water-cooled injection components 9f. The outer secondary water-cooling injection assembly 9a includes multiple rows of outer secondary cooling nozzle ring groups 9b arranged axially along the casting strand 4, and each row of outer secondary cooling nozzle ring group 9b has a plurality of outer secondary cooling nozzles uniformly distributed along the outer circumference of the casting strand 9c, a steam recovery box 9d is provided outside the outer two water-cooled injection components 9a. The foot roll 9e of the secondary cooling section is arranged between the two outer secondary water-cooling nozzle ring groups 9b adjacent up and down, so that the water flow ejected from the external secondary water-cooling nozzle 9c can be sprayed on the casting strand 4 as much as possible without being blocked by the secondary cooling nozzles. The foot roll 9e of the cold section is blocked, and the foot roll 9e of the second cold section can be used to clamp the red hot casting slab 4 with the liquid core. The inner two water-cooled injection assembly 9f includes a central water spray pipe 9g and multiple rows of inner two water-cooled nozzle groups 9j arranged axially along the central water spray pipe, and the central water spray pipe 9g is connected to the inner two water-cooled nozzle groups through the reducing joint 9h The nozzle conduit 9i inserted in the water inlet straight conduit 1h is connected to each other, the upper end of the nozzle conduit 9i passes through the water inlet straight conduit 1h and is exposed, and the lower end is located in the water inlet straight conduit 1h. Wherein, the upper and lower positions of each inner two water-cooled nozzle groups 9j may correspond to each outer two water-cooled nozzle groups 9b.

In addition, the central water spray pipe 9g can be communicated with the nozzle conduit 9i, and a water volume control switch 9k is set at the upper end of the nozzle conduit 9i to control the water spray volume of the inner two water-cooled nozzle groups 9j; or, the nozzle conduit 9i can be It can be set rotatably, and the bottom end of the nozzle conduit 9i is provided with a valve. When it is necessary to spray water from the inner two water-cooled nozzle groups 9j, open the valve so that the water in the nozzle conduit 9i flows into the central water spray pipe 9g. When the group 9j sprays water, the valve is closed, and the water in the nozzle conduit 9i cannot flow into the central spray pipe 9g.

The two inner water-cooling injection assemblies 9f of this embodiment are used to continue cooling the inner walls of the hollow cast tube blanks 4 of the inner and outer crystallizers 1 and 2 .

In this embodiment, the outer two water-cooling nozzles 9c of the outer two water-cooling spray assemblies 9a are used to continue to cool the outer surface of the cast slab out of the mold, and the outer two water-cooled spray assemblies 9a include six rows of outer nozzles arranged along the length direction of the cast slab 4. The second water-cooled nozzle ring group 9b, the figure is only for illustration, the number of nozzles depends on the cooling length can be 5 to 50 rows, each outer two water-cooled nozzle ring group 9b has a plurality of outer two water-cooled nozzles 9c, the number of outer two water-cooled nozzles 9c can be according to It depends on the requirement and the diameter of the casting slab 4, here, each outer two water-cooling nozzle ring group 9b has 6-12 outer two water-cooling nozzles 9c.

As shown in Figure 1, the tundish 7 can be a tundish that adopts electromagnetic heating, and the bottom of the tundish 7 has a molten steel opening; the top of the strand distributor 8 has a molten steel opening, and the strand distributor The bottom of 8 can be evenly distributed with 1 to 4 shunt pipes 8a, the number of shunt pipes 8a is the same as the number of the nozzle penetration hole 5e of loam cake mechanism 5, here, there are two shunt pipes 8a, that is, here The strand distributor 8 distributes the water flow in the tundish 7 into two symmetrical 180° streams and introduces them into the upper cover mechanism 5; of course, the strand distributor 8 can also distribute the water flow in the tundish 7 into one flow , three streams or more than three streams into the upper cover mechanism 5.

A plurality of rows of clamping guide rollers 12 are arranged around the lower part of the outer mold 2 for clamping the red hot casting slab 4 with a liquid core coming out of the inner mold 1 and the outer mold 2 .

The casting device also includes a lifting push rod 11, which is connected to the bottom of the circular cylindrical dummy 10, and drives the circular cylindrical dummy 10 to move up and down. In this embodiment, at the initial stage of casting, the circular cylindrical dummy 10 seals the bottom of the circular cavity below the inner and outer crystallizers 1 and 2, and as the casting progresses, the lifting push rod 11 moves toward the Periodically vibrate up and down while dragging the circular cylindrical dummy 10 downwards, so that the slab shell moves up and down relative to the inner and outer molds 1 and 2, so that the slab shell and the inner and outer molds 1 2. The purpose of shelling.

In addition, the slab shell and the inner and outer crystallizers 1 and 2 move up and down relative to each other. In addition to the above-mentioned lifting push rod 11 driving the circular cylindrical dummy 10 to move up and down, the following methods can also be used:

A billet drawing mechanism is set on the circular cylindrical dummy 10, and the blank drawing mechanism drives the circular cylindrical dummy 10 to move up and down to realize it. The cover mechanism 5 does not move; or,

A hydraulic vibration mechanism is installed between the steel structure foundations 3b, and the hydraulic vibration mechanism drags the base mechanism 6 and the inner and outer crystallizers 1, 2 to perform periodic up and down movements.

Wherein, the drawing mechanism and the hydraulic vibration mechanism are well known to those skilled in the art, and will not be repeated here.

Fig. 11 shows the results of simulation defect prediction and analysis of an actual case of the present invention. The experimental scheme is semi-continuous casting of a hollow billet with an outer diameter of Φ1800mm, a wall thickness of 500mm, a height of 11000mm, an inner hole diameter of Φ1000mm, and a test material of Q345R container steel. As shown in Figure 11, the test results: the slab casting yield is over 90%; there is no shrinkage cavity defect in the center; there is a slight loose defect in the center that can be forged and rolled. When the casting length is 20,000mm, continuous casting can be realized, and the casting yield can reach 95% to 98%.

As shown in Figure 1, the operation process of the utility model embodiment is illustrated below:

(1) Assembly: As shown in Figure 2 and Figure 6, complete the assembly work of each component, and set the dummy 10 in the lower annular cavity of the inner mold 1 and the outer mold 2, and process the peripheral gaps, that is ready for casting;

(2) Casting: Lift the qualified molten steel to the top of the tundish 7, open the ladle nozzle control system, and open the liquid outlet of the tundish 7 after the amount of molten steel in the tundish 7 reaches 80%, and the molten steel flows from the tundish 7 The molten steel outlets are respectively introduced into the nozzle penetration holes 5e of the upper cover mechanism 5 at 180 degrees to each other through the casting stream distributor 8, and the molten steel is then rotated into the round billet casting cavity of the base mechanism 6 by the tangential inrunner 6h Inside, the molten metal makes a circular motion in the casting cavity, and the scum floating on the surface of the molten metal realizes the separation of steel and slag by the difference in specific gravity during the rotation process, and is separated by the slag retaining plate 5g installed on the upper cover mechanism 5 Enter the slag discharge ditch 6i, and discharge from the slag discharge port 3a;

The molten metal is cooled and solidified by the inner crystallizer 1 and the outer mold 2 to form a billet shell. While the billet shell is drawn downward through the dummy 10, the lifting push rod 11 drives the dummy, and the billet is opposite to the mold 1, 2 Vibrate up and down to separate the billet shell from the crystallizer, and gradually move downward at the casting speed, while the effective section and wall thickness gradually increase, forming in the mold along both sides of the inner and outer molds 1 and 2 Solidify the billet shell and core liquid core; when the billet shell is pulled out of the inner and outer crystallizers, the red hot billet shell is exposed to the air and enters the second water cooling system 9;

(3) Cooling control: the red-hot large-section tube blank with liquid core entering the second water cooling system 9, the outer surface is cooled by the outer two water cooling nozzles 9c below the outer crystallizer 2, and the inner surface is cooled by the inner two water cooling nozzles The cooling temperature gradually drops, and the liquid core ratio gradually decreases until the V-shaped bottom completely forms a solid;

(4) Electromagnetic stirring and heating stop pouring: After the superheated molten metal is injected into the cavity, the cooling water circuit on the inner mold 1 and the outer mold 2 and the cooling temperature of the frequency conversion induction coil 6e drop, forming a Weak solidification layer or supercooled metal layer;

In the normal casting process, the frequency conversion induction coil 6e mainly uses periodic low-frequency alternating magnetic field to stir the supercooled metal layer, mixes the supercooled molten metal with the higher temperature liquid in the middle of the liquid, and increases the number of non-uniform cores in the molten metal; casting In the later stage, when the pulling speed is gradually reduced until the drawing is stopped, and the upper feeding liquid is only used to replenish the part equivalent to the riser required for the solidification of the V-shaped liquid core, the working frequency of the frequency conversion induction coil 6e is changed to power frequency or Intermediate frequency continuous power supply, at this time, the water-cooled frequency conversion induction coil 6e acts as an induction heating and holding furnace, and plays the role of heat preservation and heating of the riser;

Subsequently, as the liquid core decreases and the end of the liquid core gradually enters the mold, the cooling water in the inner mold 1 is gradually reduced, and the inner mold 1 is slowly raised until the remaining molten metal in the frequency conversion induction coil 6e completely enters the billet In the shell, pull out the inner crystallizer 1 completely, and cover the heat preservation material above the remaining molten metal until it is completely solidified;

(5) Stripping: In the normal continuous casting process at the lower end of the completely solidified area, the solidified billet is taken out from the casting system through the heat sink to realize continuous casting; after a certain length of continuous casting, the casting is stopped until the remaining molten metal is completely Until it is solidified (as in the step of stopping pouring in (4) above), the whole billet is finally taken out at one time to realize semi-continuous billet casting.

Compared with the traditional method, the utility model embodiment has the following advantages:

1. Since the embodiment of the utility model adopts the special fixing method of the upper cover mechanism 5, the base mechanism 6 and the central inner crystallizer 1, the fixing and concentric replacement of the inner and outer crystallizers 1 and 2 become easier and more convenient.

2. Since the embodiment of the utility model adopts the two-way cooling of the inner and outer crystallizers 1 and 2 for the billet, the effective thickness of the billet to be cooled and solidified is greatly increased, and the thickness of the billet that can be cast is nearly doubled.

3. Since the billet casting system of the embodiment of the utility model adopts the second water-cooling system of spraying water inside and outside, compared with the traditional mechanism of spraying water on a single outer surface, the cooling intensity is higher, the liquid core of the billet is short, the product is high in density, and the segregation is light ,Good quality.

4. Since the embodiment of the utility model adopts the vertical casting casting method, it avoids the inconsistency of solidification in the upper and lower sides of the circumference of the large section, and the accumulation of impurities or segregation in the upper part, which ensures the consistency of the quality of the entire billet.

5. Since the casting system of the embodiment of the utility model adopts a double tangential ingate structure, the molten metal enters the mold cavity from the tangential ingate 6 hours, which avoids the temperature and solidification inconsistency of the entire section, especially the super large section casting, and at the same time There is also the effect of separating steel slag by using the difference in specific gravity of steel slag.

6. Since the embodiment of the utility model is equipped with a slag-iron separation baffle mechanism on the track of the liquid metal rotation on the upper cover, that is, a slag baffle plate 5g, the separation and discharge of scum and pure molten metal can be effectively realized.

7. Since the inner and outer crystallizers 1 and 2 of the embodiment of the utility model both use high-strength graphite composite working linings, they can effectively protect the copper-sheathed crystallizers, have the auxiliary function of lubricating and shelling, and can realize no protective slag cast.

8. Since the embodiment of the utility model is equipped with a frequency conversion induction coil 6e, the beneficial effects of electromagnetic stirring, grain refinement, and adjustment of the temperature of the molten metal in the cavity are realized in the normal production process, and the change of the casting speed of the tail blank is also played. The heating and heat preservation of the riser of the tail billet is an important effect of shortening the shrinkage cavity and tube shrinkage of the tail billet and improving the yield of the cast billet.

In summary, due to the application of the above measures, the continuous casting of the super-large diameter and thick-walled hollow billets in the embodiment of the present invention can be realized. The phase tamping method and the heating and heat preservation effect of the tail blank of the frequency conversion induction coil have played a role in improving the quality of the casting and increasing the yield of the finished product.

The above are only a few embodiments of the present utility model, and those skilled in the art can make various changes or modifications to the embodiments of the present utility model according to the disclosure of the application documents without departing from the spirit and scope of the present utility model.

Claims (15)

1. a large-section hollow billet continuous casting device is characterized in that, said casting device comprises inner crystallizer (1), outer crystallizer (2), loam cake mechanism (5), base mechanism (6), An annular cylindrical dummy (10) with an annular cross section, a heated tundish (7) and a strand distributor (8); the base mechanism (6) and the upper cover mechanism (5) are mutually The upper cover mechanism and the base mechanism are fixedly connected up and down; the outer crystallizer is fixedly connected below the base mechanism; the inner crystallizer (1) is a columnar structure, and the inner mold (1) is fixedly connected to the On the upper cover mechanism (5), and the bottom of the inner crystallizer is passed through the inside of the upper cover mechanism and the base mechanism, so that the lower part of the inner crystallizer (1) is located at the inner side of the outer crystallizer, and Surrounded concentrically by the outer crystallizer (2), the strand distributor (8) distributes the molten metal in the tundish (7) into one or more streams and guides them into the upper cover mechanism (5), the inner The molten metal is filled between the mold (1) and the outer mold (2); at the initial stage of casting, the circular cylindrical dummy (10) is set in the annular cavity between the inner and outer molds The bottom of the body, the molten metal is cooled by the inner and outer crystallizers to form a solidified hollow tube blank (4), and the hollow tube blank is located on the circular cylindrical dummy. the 2. The large-section hollow billet continuous casting device according to claim 1, characterized in that, the inner mold (1) comprises a water inlet straight conduit (1h), a return water conduit and a cooling water circuit; the return water conduit Surrounded at intervals outside the water inlet straight conduit, the return water conduit includes a return water straight conduit connected up and down and an inner crystallizer jacket, the inner crystallizer jacket is cylindrical, and the outside of the return water conduit is coated with The first heat insulation jacket; the cooling water circuit is arranged in the inside of the inner crystallizer; the cooling water circuit includes the water inlet circuit (1a), the return water circuit (1b) and the water hole (1c); the water inlet circuit (1a ) is located in the straight water inlet conduit, the upper end of the water inlet circuit is the water inlet (1d); the gap between the straight water inlet conduit and the return water conduit (1i) constitutes the return water circuit (1b) , the upper end of the water return circuit (1b) is the water return port (1e); the water hole (1c) is arranged between the lower end of the water inlet straight conduit (1h) and the inner crystallizer jacket (1k), so The water inlet circuit (1a) and the water return circuit (1b) are connected through the water hole (1c). the 3. The large-section hollow billet continuous casting device according to claim 2, characterized in that, the first heat-insulating jacket (1g) includes a high-temperature refractory pipe (1m) and high-strength graphite (1n), and the high-temperature The refractory pipe is coated on the outside of the return water straight conduit (1j), and the high-strength graphite is coated on the outside of the inner crystallizer jacket (1k). the 4. The large-section hollow billet continuous casting device according to claim 2, characterized in that an inner mold flange (1f) is provided above the inner mold, and the inner mold (1) passes through the The inner crystallizer flange is fixed on the upper cover mechanism (5); The return water conduit (1i) also includes a return water riser conduit (1p), and the return water riser conduit is sleeved on the outside of the water inlet straight conduit at intervals and connected to the top of the return water straight conduit (1j) , the gap between the water return pipe and the water inlet straight pipe is connected with the return water circuit, the water return port (1e) is arranged on the water return pipe, and the inner crystallizer flange (1f ) is located at the top of the return water straight conduit (1j). the 5. The large-section hollow billet continuous casting device according to claim 2, characterized in that, the return water straight conduit (1j) also includes a return water flange (13a), and the inner end of the return water flange is connected to On the water inlet straight conduit (1h), the outer end is connected to the bottom of the return water straight conduit; the inner crystallizer outer casing (1k) includes an outer casing (13b) and an outer casing flange (13c) connected to the top of the outer casing , the inner end of the jacket flange is connected to the water inlet straight conduit; The inner crystallizer (1) also includes an inner mold inner sleeve (13d), and the inner mold inner sleeve includes an inner sleeve (13e) and an inner sleeve upper flange (13f) connected to the top of the inner sleeve, The inner end of the upper flange of the inner sleeve is connected to the straight water inlet pipe (1h), and the inner sleeve is arranged at intervals inside the outer sleeve; the return flange (13a), the outer flange (13c) and the upper flange of the inner sleeve are fixedly connected together up and down; the lower part of the inner sleeve (13e) is also provided with a partition (13g) and an inner sleeve end cover (13h), and the inner sleeve end cover is located at the partition Below the plate, the inner end of the partition and the end cover of the inner sleeve are connected to the straight water inlet pipe (1h), and the outer end is connected to the inner sleeve; The water holes include a first water hole (13i), a second water hole (13j), a third water hole (13k) and a fourth water hole (13m), and the first water hole radially passes through the water inlet The lower part of the conduit (1h), the second water hole radially penetrates the lower end of the inner casing (13e), and the first and second water holes are located between the partition (13g) and the inner sleeve end cover (13h), the third water hole radially penetrates the upper end of the inner casing (13e), the third water hole is located above the partition (13g), and the fourth water hole longitudinally penetrates the Return water flange (13a), outer flange and inner upper flange (13f). the 6. The large-section hollow billet continuous casting device according to claim 1, characterized in that, the upper cover mechanism (5) comprises a Z-shaped upper cover shell (5a), the upper cover shell The outer side of the bottom is connected with a first upper cover flange (5b) for connecting the base mechanism (6), and the inner cavity of the upper cover shell is built with a thermal insulation liner (5c); the upper cover mechanism The inner crystallizer perforation (5d) is provided through the central axis of the upper cover mechanism, and the nozzle penetration hole (5e) is axially penetrated on the upper cover mechanism, and the nozzle penetration hole is located in the inner mold perforation (5d) The outer side of the upper cover housing (5a) is provided with a second upper cover flange (5f) for connecting the inner crystallizer (1) at the position corresponding to the perforation of the inner crystallizer. the 7. The large-section hollow billet continuous casting device according to claim 6, characterized in that, at the bottom of the thermal insulation liner (5c), along the outer edge of the inner mold perforation (5d) A slag retaining plate (5g) is provided extending in the tangential direction; a relief hole (5h) is axially penetrated on the upper cover mechanism (5), and the relief hole is located outside the perforation hole (5d) of the inner crystallizer. The upper part of the upper cover housing (5a) is provided with an insulating cover plate (5i) covering the upper end of the release hole; The thermal insulation liner (5c) includes a refractory knotting material (5j) and a thermal insulation and refractory inner lining (5k), and the thermal insulation and refractory inner lining is connected to the bottom of the inner cavity of the upper cover shell (5a), so The refractory knotting material (5j) is filled between the upper cover shell and the heat-insulating refractory lining. the 8. The large-section hollow billet continuous casting device according to claim 1, characterized in that, the base mechanism (6) includes a concave-shaped base shell (6a), the base shell The outer side of the top is connected with a first base flange (6b) for connecting the upper cover mechanism, and the first base flange and the first upper cover flange (5b) are fixedly combined by fastening connectors, The base shell is provided with a refractory lining (6c), the central axis of the base mechanism is provided with a base center hole (6d), and the bottom of the base shell (6a) corresponds to the base The position of the central hole is provided with a second base flange (6g) for connecting the outer crystallizer (2). the 9. The large-section hollow billet continuous casting device according to claim 8, characterized in that, the upper part of the base mechanism (6) is provided with a tangential inrunner (6h ), the outer end of the tangential inrunner corresponds to the nozzle penetration hole (5e), and the inner end communicates with the center hole (6d) of the base. the 10. The large-section hollow billet continuous casting device according to claim 8, characterized in that, the lower part of the base mechanism is located on the upper ring of the outer mold with a frequency conversion induction coil (6e), and the frequency conversion induction coil surrounds Outside the center hole of the base, a coil protection cover (6f) is arranged outside the frequency conversion induction coil. the 11. The large-section hollow billet continuous casting device according to claim 8, characterized in that, the base mechanism (6) is axially provided with a slag outlet (3a), and the slag outlet is connected to the above-mentioned release Corresponding to the hole (5h), a slag discharge ditch (6i) is connected between the slag discharge port and the central hole (6d) of the base. the 12. The large-section hollow billet continuous casting device according to claim 10, characterized in that, the refractory lining (6c) comprises a high-temperature refractory lining (6k), a carbon refractory brick lining (6m) and a knotted Refractory material (6n), the high-temperature refractory lining is arranged on the upper part of the inner cavity of the base shell (6a), and the carbon refractory brick lining is arranged on the lower part of the high-temperature refractory lining and is located on the base Around the center hole (6d) of the seat, the knotted refractory material is filled between the high temperature refractory lining and the base shell, and is located outside the coil protective cover (6f). the 13. The large-section hollow billet continuous casting device according to claim 2, characterized in that, the casting device also includes a second water cooling system (9), and the second water cooling system is connected to the external mold Below, the second water-cooling system includes the outer two water-cooling injection assemblies (9a), the inner two water-cooling injection assemblies (9f) and the second cooling section foot roll (9e); the outer two water-cooling injection assemblies include along the casting strand (4 ) multiple rows of outer secondary cooling nozzle ring groups (9b) arranged in the axial direction, each row of outer secondary cooling nozzle ring groups has a plurality of outer secondary water cooling nozzles (9c) uniformly distributed along the outer circumference of the slab, and outside the outer secondary water cooling injection assembly is provided Steam recovery box (9d); said inner two water-cooled injection assemblies (9f) include a central water spray pipe (9g) and multiple rows of inner two water-cooled nozzle groups (9j) arranged axially along the central water spray pipe, said central The water spray pipe is connected to the nozzle conduit (9i) inserted in the water inlet straight conduit (1h) through a reducing joint (9h), and the upper end of the nozzle conduit (9i) passes through the water inlet straight conduit to The lower end is exposed, and the lower end is located in the water inlet straight pipe; the foot roller (9e) of the secondary cooling section is arranged between the two adjacent outer secondary water-cooling nozzle ring groups up and down, and is used to clamp the red-hot casting slab with a liquid core (4). the 14. The large-section hollow billet continuous casting device according to claim 1, characterized in that, the casting device further comprises a lifting push rod (11), and the lifting push rod is connected to the circular cylindrical dummy ingot The bottom of the device (10), and drives the dummy to move up and down. the 15. The large-section hollow billet continuous casting device according to claim 1, characterized in that, a plurality of rows of clamping guide rollers (12) are arranged around the lower part of the outer mold (2). the

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