Auxiliary slag changing device and method in small square billet casting process

Abstract

The invention relates to an auxiliary slag changing device and method in the small square billet casting process, and belongs to the technical field of continuous steel casting auxiliary equipment in the metallurgical industry. According to the technical scheme, the device comprises 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 driving motor (17) and a negative pressure pump (18), the lower slag suction bottle (1) and the upper slag suction bottle (3) are connected together through the connecting ring (2) to form the slag suction bottle, the slag suction bottle is connected with a suction pipe, a filter screen is arranged in the slag suction bottle, the slag suction bottle is connected with the negative pressure tank (14), and the driving motor (17) and the negative pressure pump (18) are arranged in the negative pressure tank (14); and a fixed connecting pipe (10) is arranged on the upper slag suction bottle (3) and is connected with a negative pressure tank (14). According to the method, the covering slag layer in the crystallizer can be rapidly and effectively pumped away, production accidents caused by water gap collision during slag replacement operation are avoided, and the slag replacement efficiency is improved.

Description

Technical Field

[0001] The invention relates to an auxiliary slag replacement device and method in a small square billet casting process, belonging to the technical field of auxiliary equipment for continuous steel casting in the metallurgical industry. Background Art

[0002] Billet casting has the characteristics of high flow rate and high casting speed. The key factor to ensure stable continuous casting production and billet quality is protective slag. Using protective slag with matching performance not only makes production stable, but also optimizes the surface quality of billets and obtains good rolled products.

[0003] During the continuous casting process, when mixing different steel grades or switching casting speeds, the mold slag replacement operation is involved. Operators often use a shovel-like slag removal tool to shovel the previous type of mold slag from the steel liquid surface in the crystallizer to the outside of the crystallizer, and then add the new type of mold slag. This operation method has the following two disadvantages: ① The cross-section of the small square billet crystallizer is small, and the submerged nozzle is inserted into it. If a slag removal tool similar to a shovel is used to remove slag and replace slag in the crystallizer, it is difficult to achieve due to the narrow internal space of the crystallizer. Even improper operation may break the nozzle, causing continuous casting production accidents, or scratch the copper plate of the crystallizer, resulting in an increase in the cost of process spare parts; ② The number of casting streams for small square billets is generally 5-7, and the replacement of protective slag for mixed casting of different steel grades must be operated simultaneously. If a shovel is used to remove the slag, it is difficult to do so. It requires the cooperation of multiple people to complete the operation in a short time, which is time-consuming and labor-intensive. Otherwise, due to the mismatch of protective slag performance in the crystallizer and uneven heat transfer of the billet, the surface of the billet will be concave and serpentine, resulting in unqualified rolled products and even rolling production accidents.

[0004] Based on the above background conditions, an auxiliary slag changing device and method for the casting process of small square billets are invented. The device can be installed with 3-5 slag suction bottles, each of which is equipped with a suction tube with a diameter of 10mm. The protective slag is collected by utilizing the negative pressure principle, and the protective slag in multiple crystallizers can be replaced at the same time. Summary of the invention

[0005] The purpose of the present invention is to provide an auxiliary slag changing device and method in the casting process of small square billets, which can quickly and effectively remove the protective slag layer in the crystallizer, avoid production accidents caused by collision with the water nozzle during slag changing operations, improve the slag changing efficiency, and solve the problems existing in the background technology.

[0006] The technical solution of the present invention is: The invention discloses an auxiliary slag changing device in a small square billet casting process, comprising a lower slag suction bottle, a connecting ring, an upper slag suction bottle, a negative pressure hose, a negative pressure tank, a driving motor and a negative pressure pump. The lower slag suction bottle and the upper slag suction bottle are connected together through a connecting ring to form a slag suction bottle. The slag suction bottle is connected to a suction pipe. A filter is arranged in 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 provided with a driving motor and a negative pressure pump.

[0007] The upper slag suction bottle is provided with a fixed connecting pipe, and the fixed connecting pipe is connected to the negative pressure tank through a negative pressure hose.

[0008] The filter screen in the residue suction bottle comprises a large filter screen and a small filter screen, the large filter screen is close to the connection between the lower residue suction bottle and the upper residue suction bottle and is fixed on the connecting ring, and the small filter screen is close to the fixed connecting pipe on the upper residue suction bottle.

[0009] The filter hole diameter of the small filter net is smaller than the filter hole diameter of the large filter net.

[0010] The lower slag suction bottle, the upper slag suction bottle and the connecting ring are connected together through threads.

[0011] The suction pipe comprises an internal suction pipe and an external suction pipe which are threadedly connected together, the internal suction pipe is located inside the lower slag suction bottle, and the external suction pipe is located outside the lower slag suction bottle.

[0012] The upper slag suction bottle is also provided with a portable handle and a slag suction switch.

[0013] The slag suction switch is connected to the driving motor and the negative pressure pump through a cable.

[0014] The lower slag suction bottle and the upper slag suction bottle are connected together by a connecting ring to form 3-5 slag suction bottles, and each slag suction bottle is connected to the negative pressure tank through a negative pressure hose.

[0015] A method for assisting slag replacement during the casting process of a small square billet is provided, using the above-mentioned device for assisting slag replacement during the casting process of a small square billet. When the protective slag is replaced in a small square billet continuous casting machine, a suction tube is placed inside a crystallizer at a certain distance from the protective slag layer, and the previous protective slag inside the crystallizer is sucked into a slag suction bottle through the negative pressure formed by a negative pressure tank (14), and 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.

[0016] The beneficial effects of the present invention are as follows: the present invention can quickly and effectively extract the protective slag layer in the crystallizer, avoid production accidents caused by collision with the water outlet during slag changing operations, and reduce quality risks caused by mismatch of protective slag performance. In addition, multiple slag suction bottles can be connected according to actual production conditions to improve slag changing efficiency and reduce the labor intensity of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the device of the present invention; Figure 2 This is a front view of the slag suction bottle of the present invention; Figure 3 for Figure 2 sectional view of Figure 4 This is a left view of the residue suction bottle of the present invention; Figure 5 for Figure 4 sectional view of Figure 6 A top view of a large filter screen of the present invention; Figure 7 A top view of a small filter screen of the present invention; In the figure: lower slag suction bottle 1, upper slag suction bottle 3, connecting ring 2, built-in suction straw 4, external suction straw 5, large filter 6, small filter 7, portable handle 8, slag suction switch 9, fixed connecting pipe 10, cable 11, negative pressure hose 12, electric control valve 13, negative pressure tank 14, pressure gauge 15, control box 16, drive motor 17, negative pressure pump 18. DETAILED DESCRIPTION

[0018] The present invention will be further described below by way of examples with reference to the accompanying drawings.

[0019] See attached Figure 1-6 , an auxiliary slag changing device in the casting process of small square billets, comprising 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 driving motor 17 and a negative pressure pump 18. The lower slag suction bottle 1 and the upper slag suction bottle 3 are connected together through the connecting ring 2 to form a slag suction bottle, the slag suction bottle is connected to a suction pipe, a filter is arranged in the slag suction bottle, the slag suction bottle is connected to the negative pressure tank 14 through the negative pressure hose 12, and the negative pressure tank 14 is provided with a driving motor 17 and a negative pressure pump 18.

[0020] In this embodiment, as shown in the attached Figure 1 As shown, the auxiliary slag replacement device in the casting process of the small square billet includes a lower slag suction bottle 1, an upper slag suction bottle 3, a connecting ring 2, a built-in suction pipe 4, an external suction pipe 5, a large filter 6, a small filter 7, a portable handle 8, a slag suction switch 9, a fixed connecting pipe 10, a cable 11, a negative pressure hose 12, an electric control 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: The negative pressure tank 14 is connected to the upper slag suction bottle 3 through a cable 11 and a negative pressure hose 12. In addition, the start and stop of the driving motor 17 and the negative pressure pump 18 are controlled by a pressure gauge 15 and a control box 16 to keep the internal pressure of the negative pressure tank 14 stable. The operator holds the portable handle 8 to place the external suction tube 5 inside the continuous casting machine crystallizer, adjusts the distance from the slag layer, presses the slag suction switch 9 to control the electric control valve 13 to open, and then performs the slag suction operation; the large filter 6 and the small filter 7 can prevent dust from entering the negative pressure hose 12 and the negative pressure tank 14, ensuring stable operation of the equipment.

[0021] As shown in the attached drawings, the connection between the lower slag suction bottle 1 and the upper slag suction bottle 3 has a threaded structure, which matches the thread on the inner side of the connecting ring 2. The lower slag suction bottle 1, the upper slag suction bottle 3 and the connecting ring 2 are connected together to form a sealed oval shell structure, which is made of stainless steel. A portable handle 8 is installed on the shell surface of the upper slag suction bottle 3, and a slag 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 shell of the upper slag suction bottle 3. The lower slag suction bottle 1 is equipped with two sections of suction pipes: an internal suction pipe 4 and an external suction pipe 5, both of which are made of stainless steel. In order to ensure that the powder slag in the lower slag suction bottle 1 does not flow back, one end of the internal suction pipe 4 is close to the large filter 6, and the other end of the external suction pipe 5 and the internal suction pipe 4 are connected to the lower slag suction bottle 1 with a threaded structure for easy replacement.

[0022] As shown in the accompanying drawings, two layers of filters are provided inside the shell of the upper slag suction bottle 3, wherein the large filter 6 is a circular filter with a longitudinal cross-section of "W" shape. There are no filter holes in the central area of ​​the filter, which is the powder slag impact area. The large filter 6 is installed close to the connecting ring 2 and is removable; the small filter 7 is a hemispherical structure, and the filter hole diameter is smaller than the large filter 6. It is installed in the fixed connecting pipe 10 and cannot be removed. Both filters are made of metal.

[0023] As attached Figure 1 As shown, the cable 11 is led out from the control box 16, and is respectively connected to the drive motor 17, the pressure gauge 15, the electric control valve 13 and the slag suction switch 9 for transmitting control signals. The negative pressure hose 12 is connected to the upper slag suction bottle 3 through the fixed connecting pipe 10, and the other end is connected to the electric control valve 13. The opening and closing of the electric control valve 13 is controlled by the slag suction switch 9. The pressure gauge 15 monitors the pressure change inside the negative pressure tank 14, and transmits the signal to the control box 16 through the cable 11. The control box 16 controls the start and stop of the drive motor 17 according to the pressure inside the negative pressure tank 14, and the drive motor 17 drives the negative pressure pump 18 to adjust the pressure inside the negative pressure tank 14 to the set value.

[0024] First, a preset pressure value is set according to the safe distance between the external suction tube 5 and the protective slag in the crystallizer, and a preset program is written into the control box 16. The start and stop of the drive motor 17 and the negative pressure pump 18 are controlled according to the internal pressure of the negative pressure tank 14. After pressing the slag suction switch 9 on the upper slag suction bottle 3, the electric control valve 13 is opened, and the slag suction bottle starts to pump air.

[0025] When replacing the protective slag in the small square billet continuous casting machine, the worker holds the portable handle 8, places the outer end of the external suction tube 5 inside the crystallizer at a certain distance from the protective slag layer, then presses the slag suction switch 9, and after the previous protective slag inside the crystallizer is sucked out, 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.

[0026] The present invention can quickly and effectively extract the protective slag layer in the crystallizer, avoid production accidents caused by collision with the water outlet during slag replacement operation, and reduce quality risks caused by mismatch of protective slag performance. In addition, according to actual production conditions, multiple slag suction bottles can be connected to improve slag replacement efficiency and reduce the labor intensity of workers.

Claims

1. An auxiliary slag replacement device in a billet casting process, characterized in that: The invention comprises 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 driving motor (17) and a negative pressure pump (18); the lower slag suction bottle (1) and the upper slag suction bottle (3) are connected together via the connecting ring (2) to form a slag suction bottle; the slag suction bottle is connected to a suction pipe; a filter screen is arranged in the slag suction bottle; the slag suction bottle is connected to the negative pressure tank (14) via the negative pressure hose (12); and the driving motor (17) and the negative pressure pump (18) are arranged in the negative pressure tank (14).

2. The auxiliary slag replacement device in the billet casting process according to claim 1, characterized in that: The upper slag suction bottle (3) is provided with a fixed connecting pipe (10), and the fixed connecting pipe (10) is connected to the negative pressure tank (14) via a negative pressure hose (12).

3. The auxiliary slag replacement device in the billet casting process according to claim 2 is characterized in that: The filter screen in the residue suction bottle comprises a large filter screen (6) and a small filter screen (7), the large filter screen (6) being close to the connection between the lower residue suction bottle (1) and the upper residue suction bottle (2) and being fixed on the connection ring (3), and the small filter screen (7) being close to the fixed connection pipe (10) on the upper residue suction bottle (3).

4. The auxiliary slag replacement device in the billet casting process according to claim 3 is characterized in that: The filter hole diameter of the small filter screen (7) is smaller than the filter hole diameter of the large filter screen (6).

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

6. The auxiliary slag replacement device in the billet casting process according to claim 1, characterized in that: The suction pipe comprises an internal suction pipe (4) and an external suction pipe (5) which are threadedly connected together, the internal suction pipe (4) being located inside the lower slag suction bottle (1), and the external suction pipe (5) being located outside the lower slag suction bottle (1).

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

8. The auxiliary slag replacement device in the billet casting process according to claim 7, 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).

9. The auxiliary slag replacement device in the 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 via a connecting ring (2) to form 3 to 5 slag suction bottles, and each slag suction bottle is connected to a negative pressure tank (14) via a negative pressure hose (12).

10. An auxiliary slag replacement method during billet casting, characterized in that: An auxiliary slag changing device in the casting process of a small square billet as described in claims 1-8 is used. When the protective slag is replaced in the small square billet continuous casting machine, a suction tube is placed inside the crystallizer at a certain distance from the protective slag layer. The negative pressure formed by the negative pressure tank (14) sucks the previous protective slag inside the crystallizer into the slag suction bottle, and then new protective slag is added; after the slag changing work is completed, the lower slag suction bottle is opened to pour out the powdered slag.

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