Vertical hollow round billet continuous casting machine and billet discharging method

Abstract

The present invention provides a vertical hollow round billet continuous casting machine and a billet discharging method. The vertical hollow round billet continuous casting machine comprises: a crystallizer; a pinch roller, which is arranged in the downstream direction of the crystallizer, and the pinch roller can cooperate with the hollow round billet dummy rod to clamp the hollow round billet dummy rod and move it; a billet clamping and lifting device, which is arranged in the downstream direction of the pinch roller, and the billet clamping and lifting device can clamp the hollow round billet dummy rod and move it in the vertical direction; a dummy rod hoisting assembly, which is arranged on one side of the billet clamping and lifting device, and the dummy rod hoisting assembly has a storage position, and the dummy rod hoisting assembly can drive the hollow round billet dummy rod to move between the storage position and the lower end of the billet clamping and lifting device. The beneficial effect of the present invention is that it can achieve the purpose of facilitating the feeding and retrieval of the hollow round billet dummy rod.

Description

Technical Field

[0001] The invention relates to the technical field of continuous casting in steel production, and in particular to a vertical hollow round billet continuous casting machine and a billet discharging method. Background Art

[0002] With the development of the steel industry, steel companies pay more and more attention to energy conservation and consumption reduction. Near-net-shape continuous casting technology can save energy, reduce investment and production costs in the subsequent process, and hollow round billet continuous casting technology is one of them. At present, seamless steel pipe manufacturers mainly use the method of solid round billet → perforation → oblique rolling rough pipe → continuous rolling pipe → reduction and sizing to produce seamless steel pipes. If the billet is made into a hollow round billet, the perforation process can be omitted, reducing the investment and production costs of pipe-piercing equipment, which has great economic benefits for steel companies.

[0003] At present, many enterprises are researching the production of hollow round billets and steel pipes by direct continuous casting process, but there is no report on industrial production. Due to the special shape of hollow round billets and the vertical production, the feeding and removal of the dummy bar requires a reasonable process flow, which can facilitate the feeding and removal of the dummy bar, simple storage, and convenient replacement and maintenance of the dummy bar head. Summary of the invention

[0004] The invention provides a vertical hollow round billet continuous casting machine and a billet discharging method, so as to achieve the purpose of facilitating the feeding and taking out of the dummy rod.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a vertical hollow round billet continuous casting machine, comprising: a crystallizer; a pinch roller, which is arranged in the downstream direction of the crystallizer, and the pinch roller can cooperate with the hollow round billet dummy rod to clamp the hollow round billet dummy rod for movement; a billet clamping and lifting device, which is arranged in the downstream direction of the pinch roller, and the billet clamping and lifting device can clamp the hollow round billet dummy rod and move it in the vertical direction; a dummy rod hoisting assembly, which is arranged on one side of the billet clamping and lifting device, and the dummy rod hoisting assembly has a storage position, and the dummy rod hoisting assembly can drive the hollow round billet dummy rod to move between the storage position and the lower end of the billet clamping and lifting device.

[0006] Furthermore, the vertical hollow round billet continuous casting machine includes an outer crystallizer and an inner crystallizer. The outer crystallizer has a accommodating cavity, and the inner crystallizer has a cylindrical structure. The inner crystallizer is sleeved in the outer crystallizer. The inner crystallizer can rotate relative to the outer crystallizer, and a lubricating oil hole for passing rapeseed oil to achieve heat transfer and lubrication is provided at the upper end of the side wall of the inner crystallizer.

[0007] Furthermore, along the direction in which the molten steel flows through the inner crystallizer, the outer diameter of the inner crystallizer gradually decreases.

[0008] Furthermore, the vertical hollow round billet continuous casting machine also includes a tundish, which is arranged upstream of the crystallizer, and the tundish is connected to the crystallizer through an immersed water inlet.

[0009] Furthermore, there are at least two submerged water inlets, and the at least two submerged water inlets are symmetrically arranged on two opposite sides of the crystallizer.

[0010] Furthermore, the vertical hollow round billet continuous casting machine also includes: an outer tube secondary cooling spray cooling system, which is arranged at the downstream position of the outer crystallizer, and the outer tube secondary cooling spray cooling system can cool the outer surface of the billet, and the pinch rollers are arranged in the downstream direction of the outer tube secondary cooling spray cooling system; an inner tube cooling system, which is arranged at the downstream position of the inner crystallizer, and the inner tube cooling system can cool the inner surface of the billet.

[0011] Furthermore, the vertical hollow round billet continuous casting machine also includes: a vertical fire cutting machine, which is arranged in the downstream direction of the clamping roller, and the vertical fire cutting machine can cut the ingot; a water retaining and cutting slag collecting device, which is arranged below the vertical fire cutting machine, and the water retaining and cutting slag collecting device is inclined between the horizontal plane; a cutting slag box, which is arranged below the water retaining and cutting slag collecting device and is used to receive cooling water and slag, and a drainage hole is provided at the bottom of the cutting slag box.

[0012] Furthermore, the vertical hollow round billet continuous casting machine also includes a steam and cutting fume collecting device, which is arranged in the downstream direction of the pinch roller and located on the opposite side of the vertical fire cutting machine.

[0013] The present invention also provides a method for discharging a hollow round billet from a vertical continuous casting machine, which adopts the above-mentioned vertical hollow round billet continuous casting machine for production operation. The method for discharging a hollow round billet from a vertical continuous casting machine comprises the following steps: step 10, transporting the hollow round billet dummy rod from a storage position to the lower end of a casting clamping and lifting device through a dummy rod hoisting assembly; step 20, transporting the hollow round billet dummy rod to a crystallizer through a casting clamping and lifting device and a pinch roller; step 30, producing castings at the crystallizer, and transporting the hollow round billet dummy rod and the castings through pinch rollers to the casting clamping and lifting device; step 40, separating the hollow round billet dummy rod from the casting, and transporting the hollow round billet dummy rod to a storage position through a dummy rod hoisting assembly.

[0014] Furthermore, the method for discharging hollow round billets from a vertical hollow round billet continuous casting machine further comprises step 50: separating a dummy bar body from a dummy bar head of a hollow round billet dummy bar, cleaning the dummy bar head outside the production line and installing the processed dummy bar head to the dummy bar body.

[0015] The beneficial effect of the present invention is that when the production operation starts, the dummy rod of the hollow round billet can be transported from the storage position to the lower end of the billet clamping and lifting device through the dummy rod winch assembly, and then the hollow round billet dummy rod is transported to the crystallizer through the billet clamping and lifting device and the clamping roller in turn. When the hollow round billet dummy rod is separated from the billet, the dummy rod of the separated hollow round billet can be transported back to the storage position through the dummy rod winch assembly, thereby achieving the purpose of facilitating the delivery and retrieval of the hollow round billet dummy rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 is a schematic diagram of a dummy bar in an embodiment of the present invention being located in a storage position;

[0018] Figure 2 is a schematic diagram of transporting a dummy bar according to an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of a dummy bar in the lowest position according to an embodiment of the present invention;

[0020] Figure 4 is a schematic diagram of a dummy bar in an embodiment of the present invention being transported to a crystallizer by pinch rollers;

[0021] Figure 5 Schematic diagram of the dummy bar in the pouring position according to the embodiment of the present invention;

[0022] Figure 6 Schematic diagram of the dummy bar at the billet head cutting position according to an embodiment of the present invention;

[0023] Figure 7 It is a schematic diagram of normal production of an embodiment of the present invention.

[0024] Reference numerals in the figure: 1. intermediate tank; 2. immersed water inlet; 3. crystallizer; 4. crystallizer vibration device; 5. inner tube cooling system; 6. outer tube secondary cooling spray cooling system; 8. clamping roller; 9. vertical fire cutting machine; 10. steam and cutting fume collecting device; 11. water retaining and cutting slag collecting device; 12. cutting slag box; 13. ingot clamping and lifting device; 14. ingot discharging inclined trolley; 15. hollow round ingot dummy rod; 16. dummy rod winch assembly. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] like Figures 1 to 7 As shown, an embodiment of the present invention provides a vertical hollow round billet continuous casting machine, comprising a crystallizer 3, a pinch roller 8, a billet clamping and lifting device 13, and a billet clamping and lifting device 13. The pinch roller 8 is arranged in the downstream direction of the crystallizer 3, and the pinch roller 8 can cooperate with the hollow round billet dummy rod 15 (dummy rod) to clamp the hollow round billet dummy rod 15 for movement. The billet clamping and lifting device 13 is arranged in the downstream direction of the pinch roller 8, and the billet clamping and lifting device 13 can clamp the hollow round billet dummy rod 15 and move it in the vertical direction. The dummy rod hoisting assembly 16 is arranged on one side of the billet clamping and lifting device 13, and the dummy rod hoisting assembly 16 has a storage position, and the dummy rod hoisting assembly 16 can drive the hollow round billet dummy rod 15 to move between the storage position and the lower end of the billet clamping and lifting device 13.

[0027] At the beginning of the production operation, the hollow round billet dummy rod 15 can be transported from the storage position to the lower end of the billet clamping and lifting device 13 by the dummy rod winch assembly 16, and then the hollow round billet dummy rod 15 is transported to the crystallizer 3 by the billet clamping and lifting device 13 and the pinch roller 8 in turn. When the hollow round billet dummy rod 15 is separated from the billet, the separated hollow round billet dummy rod 15 can be transported back to the storage position by the dummy rod winch assembly 16, so as to facilitate the delivery and retrieval of the hollow round billet dummy rod 15.

[0028] The vertical hollow round billet continuous casting machine in the embodiment of the present invention includes an outer crystallizer and an inner crystallizer. The outer crystallizer has a accommodating cavity, and the inner crystallizer has a cylindrical structure. The inner crystallizer is sleeved in the outer crystallizer. The inner crystallizer can rotate relative to the outer crystallizer, and a lubricating oil hole for passing rapeseed oil to achieve heat transfer and lubrication is provided at the upper end of the side wall of the inner crystallizer.

[0029] Injecting rapeseed oil through the lubricating oil hole on the inner crystallizer can carbonize the rapeseed oil under the action of the hot billet and fill the air gap between the billet shell and the inner crystallizer to play a role in heat transfer and lubrication. At the same time, the inner crystallizer has a rotating function, which is very conducive to demoulding and cooling when combined with the carbon layer formed by rapeseed oil, thereby effectively preventing the hollow billet from locking the inner crystallizer.

[0030] The outer diameter of the inner crystallizer gradually decreases along the direction in which the molten steel flows through the inner crystallizer. Specifically, the length of the inner crystallizer is 700 mm to 900 mm, and the taper of the inner crystallizer is 0.5% / m to 0.8% / m. The inner crystallizer is set to an inverted taper structure, which can facilitate the demoulding of the casting and prevent the casting from being easily stuck in the inner crystallizer.

[0031] It should be noted that the vertical hollow round billet continuous casting machine further includes a tundish 1, which is arranged upstream of the crystallizer 3, and the tundish 1 is connected to the crystallizer 3 through an immersion nozzle 2. Preferably, there are at least two immersion nozzles 2, and at least two immersion nozzles 2 are symmetrically arranged on two opposite sides of the crystallizer 3.

[0032] The molten steel flows into the intermediate tank 1 through the ladle, and then enters the crystallizer 3 through the submerged water inlet 2. There are two submerged water inlets 2, which are respectively distributed on the left and right sides of the crystallizer 3. The submerged water inlet 2 has a single-sided opening. After the molten steel comes out of the two submerged water inlets 2, it forms a counterclockwise circulation. Through the circulation movement, the slag inclusions and bubbles in the molten steel can float up, and at the same time, the temperature of the molten steel can be made uniform, reducing the slag inclusions, pores, and microcracks on the surface of the continuous casting billet, improving the quality of the continuous casting billet, and playing a role similar to the electromagnetic stirring of the crystallizer, but without the need for electricity.

[0033] The vertical hollow round billet continuous casting machine further comprises a mold vibrating device 4, which is arranged outside the crystallizer 3 and can oscillate the crystallizer 3. The crystallizer vibrating device 4 can make the crystallizer 3 perform arc-like motion along the radius of the continuous casting machine according to given amplitude, frequency and waveform deflection characteristics, making demoulding easier.

[0034] Further, the vertical hollow round billet continuous casting machine further comprises an outer tube secondary cooling spray cooling system 6 and an inner tube cooling system 5. The outer tube secondary cooling spray cooling system 6 is arranged at a downstream position of the outer crystallizer 3, and the outer tube secondary cooling spray cooling system 6 can cool the outer surface of the billet, and the pinch roller 8 is arranged in the downstream direction of the outer tube secondary cooling spray cooling system 6. The inner tube cooling system 5 is arranged at a downstream position of the inner crystallizer 3, and the inner tube cooling system 5 can cool the inner surface of the billet.

[0035] After the solidified billet leaves the outer crystallizer, an outer tube secondary cooling spray cooling system 6 is provided at the outer tube billet. The outer tube secondary cooling spray cooling system 6 is consistent with the cooling configuration of conventional round billets and adopts mist cooling. After the solidified billet leaves the inner crystallizer, an inner tube cooling system 5 is provided at the inner tube billet to cool the inner tube of the billet to prevent the billet from being overheated and causing steel leakage. The cooling medium of the inner tube cooling system 5 is high-temperature steam for cooling, not water, to prevent the molten steel from exploding in contact with water after steel leakage.

[0036] Preferably, the vertical hollow round billet continuous casting machine also includes a vertical fire cutting machine 9, a water retaining and cutting slag collecting device 11 and a cutting slag material box 12. The vertical fire cutting machine 9 is arranged in the downstream direction of the clamping roller 8, and the vertical fire cutting machine 9 can cut the ingot. After the ingot reaches the set length, it can be cut by the vertical fire cutting machine 9, so that the ingot is divided into ingot segments of set length. The water retaining and cutting slag collecting device 11 is arranged below the vertical fire cutting machine 9, and the water retaining and cutting slag collecting device 11 is inclined to the horizontal plane. The cutting slag material box 12 is arranged below the water retaining and cutting slag collecting device 11 and is used to receive cooling water and slag, and a drainage hole is arranged at the bottom of the cutting slag material box 12.

[0037] A water retaining and cutting slag collecting device 11 is provided below the cutting gun of the vertical flame cutting machine 9. The cutting slag and secondary cooling water enter the cutting slag material box 12 through the water retaining and cutting slag collecting device 11. A drainage hole is provided at the bottom of the cutting slag material box 12. The drainage is collected and discharged through a submersible pump.

[0038] The vertical hollow round billet continuous casting machine further comprises a steam and cutting fume collecting device 10, which is arranged in the downstream direction of the pinch roller 8 and on the opposite side of the vertical fire cutter 9. The steam and cutting fume collecting device 10 is used to collect the steam ejected from the inner tube cooling system 5 and the fume generated by the vertical fire cutter 9 when cutting the billet.

[0039] The embodiment of the present invention further includes a billet discharging inclined trolley 14, which is arranged on one side of the billet clamping and lifting device 13 and is located below the dummy bar hoist assembly 16. After the vertical flame cutting machine 9 cuts the billet, the billet is transported downward to the billet discharging inclined trolley 14, which transports the billet to a horizontal position, and then the billet is unloaded by a transport roller or a crane to realize the production of the billet.

[0040] It should be noted that the above-mentioned ingot rod hoisting assembly 16 is arranged above the billet discharge inclined-pull trolley 14, and the two do not interfere with each other, and the track of the billet discharge inclined-pull trolley 14 and the track of the ingot rod hoisting assembly 16 are mostly parallel to each other, so as to achieve the purpose of not interfering with the billet discharge system and sharing space as much as possible.

[0041] The present invention also provides a method for discharging a hollow round billet from a vertical continuous casting machine, wherein the vertical continuous casting machine is used for production operation, and the method for discharging a hollow round billet from a vertical continuous casting machine comprises the following steps:

[0042] Step 10: The hollow round billet dummy bar 15 is transported from the storage position to the lower end of the billet clamping and lifting device 13 by the dummy bar hoisting assembly 16;

[0043] Step 20, transport the hollow round billet dummy rod 15 to the crystallizer 3 through the billet clamping and lifting device 13 and the pinch roller 8;

[0044] Step 30, producing a cast billet at the crystallizer 3, and transporting the hollow round billet dummy rod 15 and the cast billet to the billet clamping and lifting device 13 through the pinch rollers 8;

[0045] Step 40 , separate the hollow round billet dummy bar 15 from the cast billet, and transport the hollow round billet dummy bar 15 to a storage position via the dummy bar hoist assembly 16 .

[0046] Step 50: Separate the dummy bar body and the dummy bar head of the hollow round billet dummy bar 15, clean the dummy bar head outside the production line, and install the processed dummy bar head to the dummy bar body.

[0047] The specific steps will refer to Figures 1 to 7 For detailed explanation:

[0048] like Figure 1 As shown, the hollow round billet dummy bar 15 is in the storage position, and the billet clamping and lifting device 13 is in the lowest position. The production of the vertical hollow round billet continuous casting machine starts with sending the dummy bar, and the dummy bar hoisting assembly 16 sends the hollow round billet dummy bar 15 from the storage position downward to the bottom of the continuous casting machine foundation pit.

[0049] exist Figure 2 In the position shown, the dummy bar trolley of the dummy bar hoisting assembly 16 slides down along the track to the lowest position. Due to the guidance of the guide wheel and the guide rail, the hollow round billet dummy bar 15 can be kept vertical when it is in the lowest position.

[0050] exist Figure 3 In the position shown, after the hollow round billet dummy bar 15 enters the lowest position, the clamping device of the billet clamping and lifting device 13 clamps the hollow round billet dummy bar 15, and the dummy bar trolley of the dummy bar hoisting assembly 16 releases the hollow round billet dummy bar 15.

[0051] like Figure 4 As shown, the billet clamping and lifting device 13 clamps the hollow round billet dummy rod 15 and moves upward. When the rod body of the hollow round billet dummy rod 15 enters the second-to-last pinch roller 8, the billet clamping and lifting device 13 stops running, and the pinch rollers 8 of the first and second-to-last frames are pressed down to clamp the hollow round billet dummy rod 15. Then, the clamping device of the billet clamping and lifting device 13 releases the hollow round billet dummy rod 15. The pinch rollers 8 are started to send the hollow round billet dummy rod 15 upward. When the head of the hollow round billet dummy rod 15 passes through the pinch rollers of the third frame, the pinch rollers of the third frame are pressed down, and the pinch rollers of the following frames are also pressed down. When the last pinch roller is 500mm away from the tail of the hollow round billet dummy rod 15, the last pinch roller is lifted and released, and the other pinch rollers are also 500mm away from the tail of the hollow round billet dummy rod 15. When the dummy head enters the bottom of the crystallizer 3 by 100mm, the pinch roller 8 stops running. At this moment, the hollow round billet dummy rod 15 enters the pouring position, as shown in the attached figure. Figure 5 shown.

[0052] After the workers seal the ingot, they are ready to start pouring. The molten steel flows from the ladle into the tundish 1, and then enters the crystallizer 3 through the immersion nozzle 2. The molten steel forms a hollow billet under the cooling of the inner and outer crystallizers. When the liquid level of the crystallizer 3 reaches a certain height, the pinch roller 8 is started, and the hollow round billet ingot rod 15 is clamped and moved downward, and the hollow round billet ingot rod 15 pulls the billet downward together. After the newly solidified billet leaves the outer crystallizer, the outer tube billet has an outer tube secondary cooling spray cooling system 6. After the newly solidified billet leaves the inner crystallizer, the inner tube billet has an inner tube cooling system 5 to cool the inner tube of the billet to prevent the billet from heating up too high and causing steel leakage.

[0053] When the hollow round billet dummy rod 15 runs into the billet clamping and lifting device 13, the billet clamping and lifting device 13 clamps the hollow round billet dummy rod 15. The billet clamping and lifting device 13 moves with the billet. When the head of the hollow round billet dummy rod 15 passes through the vertical flame cutting machine 9, the vertical flame cutting machine 9 starts to cut off the head of the billet. Figure 6 shown.

[0054] After the vertical flame cutting machine 9 cuts off, the billet clamping and lifting device 13 starts and moves downward quickly to transport the hollow round billet dummy bar 15 and the billet head to the lowest position. The dummy bar trolley of the dummy bar hoist assembly 16 clamps the hollow round billet dummy bar 15, and the billet clamping and lifting device 13 releases the hollow round billet dummy bar 15. The dummy bar hoist assembly 16 starts and moves upward to transport the hollow round billet dummy bar 15 and the billet head to the dummy bar storage position, as shown in the attached Figure 7 shown.

[0055] The head of the hollow round billet dummy bar 15 is disassembled from the rod body of the hollow round billet dummy bar 15 by means of a workshop overhead crane or a special electric hoist on the hollow round billet dummy bar 15, and the head of the hollow round billet dummy bar 15 and the billet head are hoisted away together, and after the off-line processing is completed, the head of the hollow round billet dummy bar 15 is installed back on the rod body of the hollow round billet dummy bar 15. This process does not interfere with production and does not occupy production preparation time.

[0056] The billet clamping and lifting device 13 clamps the billet before the vertical fire cutting machine 9 cuts it and moves with the billet. After the vertical fire cutting machine 9 cuts the billet, the billet is transported downward to the billet discharge inclined trolley 14. The billet clamping and lifting device 13 releases the billet, and the billet discharge inclined trolley 14 clamps the billet, which is then transported to a horizontal position by the billet discharge inclined trolley 14. After reaching the horizontal position, the clamping is released and the billet is taken off the production line by a transport roller or an overhead crane, thereby realizing the production of hollow round billets.

[0057] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: when the production operation starts, the hollow round billet dummy rod can be transported from the storage position to the lower end of the billet clamping and lifting device through the dummy rod winch assembly, and then the hollow round billet dummy rod is transported to the crystallizer through the billet clamping and lifting device and the clamping roller in turn; when the hollow round billet dummy rod is separated from the billet, the separated hollow round billet dummy rod can be transported back to the storage position through the dummy rod winch assembly, so as to facilitate the delivery and retrieval of the hollow round billet dummy rod.

[0058] The production of hollow round billets is realized, which can effectively prevent the billet from being stuck to the copper tube of the inner crystallizer. At the same time, the rotation of the billet in the crystallizer is realized through the single-side opening of the double water nozzle, which improves the billet quality and saves energy.

[0059] The above is only a specific embodiment of the present invention, and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the patent of the present invention, should still fall within the scope of this patent. In addition, the technical features of the present invention can be freely combined with each other, with each other, and with each other.

Claims

1. A vertical hollow round billet continuous casting machine, characterized in that: include: Crystallizer (3); A pinch roller (8) is arranged in the downstream direction of the crystallizer (3), and the pinch roller (8) can cooperate with the hollow round billet dummy rod (15) to clamp the hollow round billet dummy rod (15) for movement; A casting blank clamping and lifting device (13) is arranged in the downstream direction of the pinch roller (8), and the casting blank clamping and lifting device (13) is capable of clamping the hollow round billet dummy rod (15) and moving it in the vertical direction; A dummy bar hoist assembly (16) is arranged on one side of the billet clamping and lifting device (13), the dummy bar hoist assembly (16) having a storage position, and the dummy bar hoist assembly (16) can drive the hollow round billet dummy bar (15) to move between the storage position and the lower end of the billet clamping and lifting device (13); A vertical fire cutting machine (9) is arranged in the downstream direction of the pinch roller (8), and the vertical fire cutting machine (9) is capable of cutting the ingot; The billet discharging inclined trolley (14) is arranged on one side of the billet clamping and lifting device (13) and is located below the dummy rod hoist assembly (16). After the vertical fire cutting machine (9) cuts the billet, the billet discharging inclined trolley (14) transports the billet to a horizontal position; the dummy rod hoist assembly (16) is arranged above the billet discharging inclined trolley (14), and the two do not interfere with each other, and the track of the billet discharging inclined trolley (14) and the track of the dummy rod hoist assembly (16) are mostly parallel to each other, so as to achieve the purpose of not interfering with the billet discharging system and sharing space as much as possible.

2. The vertical hollow round billet continuous casting machine according to claim 1, characterized in that: The invention comprises an outer crystallizer and an inner crystallizer, wherein the outer crystallizer has a containing cavity, the inner crystallizer is in a cylindrical structure, the inner crystallizer is sleeved in the outer crystallizer, the inner crystallizer can rotate relative to the outer crystallizer, and a lubricating oil hole for introducing rapeseed oil to achieve heat transfer and lubrication is arranged at the upper end of the side wall of the inner crystallizer.

3. The vertical hollow round billet continuous casting machine according to claim 2, characterized in that: Along the direction in which the molten steel flows through the inner crystallizer, the outer diameter of the inner crystallizer gradually decreases.

4. The vertical hollow round billet continuous casting machine according to claim 1, characterized in that: The vertical hollow round billet continuous casting machine further comprises a tundish (1) which is arranged upstream of the crystallizer (3); the tundish (1) is connected to the crystallizer (3) via a submerged water inlet (2).

5. The vertical hollow round billet continuous casting machine according to claim 4, characterized in that: There are at least two submerged water inlets (2), and at least two of the submerged water inlets (2) are symmetrically arranged on two opposite sides of the crystallizer (3).

6. The vertical hollow round billet continuous casting machine according to claim 2, characterized in that: The vertical hollow round billet continuous casting machine also includes: An outer tube secondary cooling spray cooling system (6) is arranged at a downstream position of the outer crystallizer, the outer tube secondary cooling spray cooling system (6) is capable of cooling the outer surface of the ingot, and the pinch roller (8) is arranged in the downstream direction of the outer tube secondary cooling spray cooling system (6); An inner tube cooling system (5) is arranged at a downstream position of the inner crystallizer, and the inner tube cooling system (5) is capable of cooling the inner surface of the cast billet.

7. The vertical hollow round billet continuous casting machine according to claim 6, characterized in that: The vertical hollow round billet continuous casting machine also includes: A water retaining and cutting slag collecting device (11) is arranged below the vertical flame cutting machine (9), and the water retaining and cutting slag collecting device (11) is arranged obliquely with respect to a horizontal plane; A cutting slag box (12) is arranged below the water retaining and cutting slag collecting device (11) and is used to receive cooling water and slag. A drainage hole is arranged at the bottom of the cutting slag box (12).

8. The vertical hollow round billet continuous casting machine according to claim 7, characterized in that: The vertical hollow round billet continuous casting machine further comprises a steam and cutting fume collecting device (10), which is arranged in the downstream direction of the pinch roller (8) and is located on the opposite side of the vertical fire cutting machine (9).

9. A method for discharging a hollow round billet from a vertical continuous casting machine, using the vertical hollow round billet continuous casting machine according to any one of claims 1 to 8 for production operation, characterized in that: The method for discharging a hollow round billet from a vertical hollow round billet continuous casting machine comprises the following steps: Step 10, transporting the hollow round billet dummy bar (15) from the storage position to the lower end of the billet clamping and lifting device (13) by means of the dummy bar hoisting assembly (16); Step 20, transporting the hollow round billet dummy rod (15) to the crystallizer (3) via the billet clamping and lifting device (13) and the pinch rollers (8); Step 30, producing a cast billet at the crystallizer (3), and transporting the hollow round billet dummy rod (15) and the cast billet to the cast billet clamping and lifting device (13) via the pinch rollers (8); Step 40: Separate the hollow round billet dummy rod (15) from the cast billet, and transport the hollow round billet dummy rod (15) to the storage position via a dummy rod hoist assembly (16).

10. The method for discharging a hollow round billet from a vertical continuous casting machine according to claim 9, characterized in that: The method for discharging a hollow round billet from a vertical continuous casting machine further comprises step 50: separating a dummy bar body and a dummy bar head of the hollow round billet dummy bar (15), cleaning the dummy bar head outside the production line and installing the processed dummy bar head onto the dummy bar body.

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