An auxiliary slag replacement device and method in the casting process of small square billets

Abstract

This invention relates to an auxiliary slag replacement device and method in the casting process of small billets, belonging to the technical field of auxiliary equipment for continuous steel casting in the metallurgical industry. The technical solution includes a lower slag suction bottle (1), a connecting ring (2), an upper slag suction bottle (3), a negative pressure hose (12), a negative pressure tank (14), a drive motor (17), and a negative pressure pump (18). The lower slag suction bottle (1) and the upper slag suction bottle (3) are connected together by the connecting ring (2) to form the slag suction bottle. The slag suction bottle is connected to a suction pipe, and a filter screen is provided inside the slag suction bottle. The slag suction bottle is connected to the negative pressure tank (14), which contains the drive motor (17) and the negative pressure pump (18). A fixed connecting pipe (10) is provided on the upper slag suction bottle (3), and the fixed connecting pipe (10) is connected to the negative pressure tank (14). This invention can quickly and effectively remove the protective slag layer inside the crystallizer, avoiding production accidents caused by collisions with the nozzle during slag replacement operations, and improving slag replacement efficiency.

Description

Technical Field

[0001] This invention relates to an auxiliary slag replacement device and method in the casting process of small billets, belonging to the technical field of auxiliary equipment for continuous steel casting in the metallurgical industry. Background Technology

[0002] Small billet casting is characterized by a high number of streams and a fast casting speed. The key factor in ensuring stable continuous casting production and billet quality is the protective slag. Using a protective slag with matching properties not only stabilizes production but also optimizes the surface quality of the billet, resulting in high-quality rolled products.

[0003] During continuous casting, when mixing different steel grades or changing casting speeds, the protective slag needs to be replaced. Operators typically use a shovel-like tool to remove the previous type of protective slag from the molten steel surface inside the mold to the outside before adding the new type. This method has the following two drawbacks:

[0004] ① The cross-section of the small billet crystallizer is relatively small, and the submersible nozzle is inserted into it. If a slag-removing tool similar to a shovel is used to remove slag and replace slag inside the crystallizer, it is difficult to do so due to the narrow internal space of the crystallizer. Improper operation may even break the nozzle, causing a continuous casting production accident, or scratch the copper plate of the crystallizer, resulting in increased cost of process spare parts.

[0005] ② The number of pouring streams for small square billets is generally 5-7. However, when different steel grades are mixed and the protective slag is replaced, the operation must be carried out simultaneously. If a shovel is used to remove the slag, it is difficult. It takes many people to complete the operation in a short time, which is time-consuming and labor-intensive. Otherwise, due to the mismatch of the properties of the protective slag in the crystallizer, the heat transfer of the billet is uneven, which causes the surface of the billet to be concave and serpentine, resulting in unqualified rolled products or even rolling production accidents.

[0006] Based on the above background conditions, an auxiliary slag replacement device and method for the casting process of small billets is invented. The device can be equipped with 3-5 slag suction bottles, each with a suction tube with a diameter of 10mm. It uses the principle of negative pressure to collect protective slag and can simultaneously perform slag replacement operations in multiple crystallizers. Summary of the Invention

[0007] The purpose of this invention is to provide an auxiliary slag replacement device and method in the casting process of small billets, which can quickly and effectively remove the protective slag layer in the crystallizer, avoid production accidents caused by collision with the sprue during slag replacement operations, improve slag replacement efficiency, and solve the problems existing in the background art.

[0008] The technical solution of this invention is:

[0009] An auxiliary slag replacement device in the casting process of small billets includes a lower slag suction bottle, a connecting ring, an upper slag suction bottle, a negative pressure hose, a negative pressure tank, a drive motor, and a negative pressure pump. The lower and upper slag suction bottles are connected together by the connecting ring to form a slag suction bottle. The slag suction bottle is connected to a suction pipe. A filter screen is installed inside the slag suction bottle. The slag suction bottle is connected to the negative pressure tank through a negative pressure hose. The negative pressure tank is equipped with a drive motor and a negative pressure pump.

[0010] The upper slag suction bottle is equipped with a fixed connecting pipe, which is connected to the negative pressure tank through a negative pressure hose.

[0011] The filter screen inside the slag suction bottle includes a large filter screen and a small filter screen. The large filter screen is located near the connection between the lower and upper slag suction bottles and is fixed on the connecting ring. The small filter screen is located near the fixed connecting pipe on the upper slag suction bottle.

[0012] The diameter of the filter pores in the small filter screen is smaller than that in the large filter screen.

[0013] The lower suction bottle, the upper suction bottle, and the connecting ring are connected together by threads.

[0014] The straw comprises an inner straw and an outer straw that are threaded together. The inner straw is located inside the lower slag-sucking bottle, and the outer straw is located outside the lower slag-sucking bottle.

[0015] The upper slag suction bottle is also equipped with a portable handle and a slag suction switch.

[0016] The slag suction switch is connected to the drive motor and the negative pressure pump via cables.

[0017] The lower and upper suction bottles are connected together by a connecting ring to form 3-5 suction bottles, and each suction bottle is connected to the negative pressure tank through a negative pressure hose.

[0018] An auxiliary slag replacement method in the casting process of small billets is adopted. The auxiliary slag replacement device in the casting process of small billets described above is used. When the protective slag is replaced in the continuous casting machine of small billets, the suction pipe is placed inside the crystallizer and at a certain distance from the protective slag layer. The previous protective slag inside the crystallizer is sucked into the suction bottle by the negative pressure formed by the negative pressure tank (14), and then new protective slag is added. After the slag replacement work is completed, the lower suction bottle is opened and the powdered slag is poured out.

[0019] The beneficial effects of this invention are: it can quickly and effectively remove the protective slag layer inside the crystallizer, avoid production accidents caused by collisions with the nozzle during slag replacement operations, reduce quality risks caused by mismatch in protective slag performance, and, depending on the actual production situation, multiple slag suction bottles can be connected to improve slag replacement efficiency while reducing the labor intensity of workers. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the device of the present invention;

[0021] Figure 2 This is a front view of the slag suction bottle of the present invention;

[0022] Figure 3 for Figure 2 Cross-sectional view;

[0023] Figure 4 This is a left view of the slag suction bottle of the present invention;

[0024] Figure 5 for Figure 4 Cross-sectional view;

[0025] Figure 6 This is a top view of the large filter screen of the present invention;

[0026] Figure 7 This is a top view of the small filter screen of the present invention;

[0027] In the diagram: 1. Lower suction bottle; 3. Upper suction bottle; 2. Connecting ring; 4. Internal suction tube; 5. External suction tube; 6. Large filter screen; 7. Small filter screen; 8. Portable handle; 9. Suction switch; 10. Fixed connecting pipe; 11. Cable; 12. Negative pressure hose; 13. Electrically controlled valve; 14. Negative pressure tank; 15. Pressure gauge; 16. Control box; 17. Drive motor; 18. Negative pressure pump. Detailed Implementation

[0028] The invention will be further described below with reference to the accompanying drawings and examples.

[0029] See attached document Figure 1-6 An auxiliary slag replacement device in the casting process of small billets includes a lower slag suction bottle 1, a connecting ring 2, an upper slag suction bottle 3, a negative pressure hose 12, a negative pressure tank 14, a drive motor 17, and a negative pressure pump 18. The lower slag suction bottle 1 and the upper slag suction bottle 3 are connected together by the connecting ring 2 to form a slag suction bottle. The slag suction bottle is connected to a suction pipe and has a filter screen inside. The slag suction bottle is connected to the negative pressure tank 14 through the negative pressure hose 12. The negative pressure tank 14 is equipped with the drive motor 17 and the negative pressure pump 18.

[0030] In this embodiment, as shown in the appendix Figure 1 As shown, the auxiliary slag replacement device in the small billet casting process includes a lower slag suction bottle 1, an upper slag suction bottle 3, a connecting ring 2, an internal suction pipe 4, an external suction pipe 5, a large filter screen 6, a small filter screen 7, a portable handle 8, a slag suction switch 9, a fixed connecting pipe 10, a cable 11, a negative pressure hose 12, an electrically controlled valve 13, a negative pressure tank 14, a pressure gauge 15, a control box 16, a drive motor 17, and a negative pressure pump 18, wherein:

[0031] The negative pressure tank 14 is connected to the upper suction bottle 3 via cable 11 and negative pressure hose 12. In addition, the start and stop of the drive motor 17 and the negative pressure pump 18 are controlled by pressure gauge 15 and control box 16 to maintain the internal pressure of the negative pressure tank 14.

[0032] The operator uses a handheld portable handle 8 to place the external suction pipe 5 inside the continuous casting machine crystallizer, adjusts the distance between it and the slag layer, and presses the slag suction switch 9 to control the opening of the electric control valve 13 to perform the slag suction operation; the large filter screen 6 and the small filter screen 7 can prevent dust from entering the negative pressure hose 12 and the negative pressure tank 14, ensuring stable operation of the equipment.

[0033] As shown in the attached diagram, the connection between the lower suction bottle 1 and the upper suction bottle 3 has a threaded structure that matches the thread on the inner side of the connecting ring 2. The lower suction bottle 1, the upper suction bottle 3, and the connecting ring 2 are connected together to form a sealed oval shell structure made of stainless steel. A portable handle 8 is installed on the surface of the upper suction bottle 3 shell, and a suction switch 9 is installed next to the portable handle 8. In addition, a fixed connecting pipe 10 is also provided on the tail surface of the upper suction bottle 3 shell. The lower suction bottle 1 is equipped with two suction tubes: an internal suction tube 4 and an external suction tube 5, both made of stainless steel. To ensure that the powder and slag in the lower suction bottle 1 do not flow back, one end of the internal suction tube 4 is close to the large filter screen 6, and the other end of the external suction tube 5 is connected to the lower suction bottle 1 with a threaded structure for easy replacement.

[0034] As shown in the attached diagram, the upper slag suction bottle 3 has two layers of filter screens inside its shell. The large filter screen 6 is a circular filter screen with a longitudinal cross-section in the shape of a "W". There are no filter holes in the central area of ​​the filter screen, which is the area where the powder and slag impact. The large filter screen 6 is installed near the connecting ring 2 and is removable. The small filter screen 7 has a hemispherical structure with a filter hole diameter smaller than that of the large filter screen 6. It is installed at the fixed connecting pipe 10 and is not removable. Both filter screens are made of metal.

[0035] As attached Figure 1 As shown, cable 11 extends from control box 16 and connects to drive motor 17, pressure gauge 15, electrically controlled valve 13, and slag suction switch 9, respectively, for transmitting control signals. Negative pressure hose 12 is connected to upper slag suction bottle 3 via fixed connecting pipe 10, with the other end connected to electrically controlled valve 13. The opening and closing of electrically controlled valve 13 is controlled by slag suction switch 9. Pressure gauge 15 monitors pressure changes inside negative pressure tank 14 and transmits the signal to control box 16 via cable 11. Control box 16 controls the start and stop of drive motor 17 based on the pressure inside negative pressure tank 14. Drive motor 17 drives negative pressure pump 18 to adjust the pressure inside negative pressure tank 14 to the set value.

[0036] First, set the preset pressure value according to the safe distance between the external suction pipe 5 and the protective slag inside the crystallizer. Write the preset program into the control box 16. Control the start and stop of the drive motor 17 and the negative pressure pump 18 according to the internal pressure of the negative pressure tank 14. After pressing the suction switch 9 on the suction bottle 3, the electric control valve 13 opens, and the suction bottle starts to pump air.

[0037] When changing the protective slag on the small billet continuous casting machine, the worker holds a portable handle 8 and places the outer end of the external suction tube 5 inside the crystallizer at a certain distance from the protective slag layer. At this time, the worker presses the slag suction switch 9 to suck out the previous protective slag inside the crystallizer. Then, new protective slag is added. After the slag replacement work is completed, the lower slag suction bottle is opened to pour out the powdered slag.

[0038] This invention can quickly and effectively remove the protective slag layer inside the crystallizer, avoiding production accidents caused by collisions with the nozzle during slag replacement operations, reducing quality risks caused by mismatch in protective slag performance, and, depending on actual production conditions, multiple slag suction bottles can be connected to improve slag replacement efficiency while reducing the labor intensity of workers.

Claims

1. An auxiliary slag-changing device in the casting process of small square billets, characterized in that: It includes a lower suction bottle (1), a connecting ring (2), an upper suction bottle (3), a negative pressure hose (12), a negative pressure tank (14), a drive motor (17), and a negative pressure pump (18). The lower suction bottle (1) and the upper suction bottle (3) are connected together by the connecting ring (2) to form a suction bottle. The suction bottle is connected to a suction pipe. A filter screen is provided inside the suction bottle. The suction bottle is connected to the negative pressure tank (14) through the negative pressure hose (12). The negative pressure tank (14) is equipped with a drive motor (17) and a negative pressure pump (18). The upper slag suction bottle (3) is provided with a fixed connecting pipe (10), which is connected to the negative pressure tank (14) through a negative pressure hose (12); The filter screen inside the slag suction bottle includes a large filter screen (6) and a small filter screen (7). The large filter screen (6) is close to the connection between the lower slag suction bottle (1) and the upper slag suction bottle (3) and is fixed on the connecting ring (3). The small filter screen (7) is close to the fixed connecting pipe (10) on the upper slag suction bottle (3). The large filter (6) is a circular filter with a longitudinal cross-section in the shape of a "W", and there are no filter holes in the central area of ​​the filter. The small filter (7) has a hemispherical structure, and the diameter of the filter holes of the small filter (7) is smaller than that of the large filter (6).

2. The auxiliary slag replacement device in the small billet casting process according to claim 1, characterized in that: The lower suction bottle (1), the upper suction bottle (3), and the connecting ring (2) are connected together by threads.

3. The auxiliary slag replacement device in the small billet casting process according to claim 1, characterized in that: The straw includes an internal straw (4) and an external straw (5) that are threaded together. The internal straw (4) is located inside the lower slag bottle (1), and the external straw (5) is located outside the lower slag bottle (1).

4. The auxiliary slag replacement device in the small billet casting process according to claim 1, characterized in that: The upper slag suction bottle (3) is also equipped with a portable handle (8) and a slag suction switch (9).

5. An auxiliary slag-changing device in the casting process of small square billets according to claim 4, characterized in that: The slag suction switch (9) is connected to the drive motor (17) and the negative pressure pump (18) via a cable (11).

6. The auxiliary slag replacement device in the small billet casting process according to claim 1, characterized in that: The lower slag suction bottle (1) and the upper slag suction bottle (3) are connected together by a connecting ring (2) to form 3-5 slag suction bottles. Each slag suction bottle is connected to the negative pressure tank (14) through a negative pressure hose (12).

7. An auxiliary slag replacement method in the casting process of small square billets, characterized in that: Using the auxiliary slag replacement device in the casting process of small billets as described in any one of claims 1-6, when the protective slag is replaced in the small billet continuous casting machine, the suction pipe is placed inside the crystallizer and at a certain distance from the protective slag layer. The previous protective slag inside the crystallizer is sucked into the suction bottle by the negative pressure formed by the negative pressure tank (14), and then new protective slag is added. After the slag replacement work is completed, the lower suction bottle is opened and the powdered slag is poured out.

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