CN210817448U - Immersion type water gap for continuous casting of square and round billets - Google Patents

Abstract

The utility model relates to a square, for circle base continuous casting immersion nozzle belongs to continuous casting technical field. The four side holes of the water gap are uniformly distributed on the circumference of the central hole of the water gap, and the distance between the plane of the inner wall of each side hole and the symmetrical plane of the central hole parallel to the plane is 1/4-1/3 of the radius of the central hole of the water gap; the outer wall of the side hole consists of two vertical planes which are intersected to form an obtuse angle, wherein the vertical plane close to the central hole is along the radial direction of the nozzle, and the distance between the intersection line and the wall surface of the central hole of the nozzle is within the range of 1/3-1/2 nozzle wall thickness. The inner wall of the side hole and the radial section of the outer wall of the side hole form a certain angle. The side hole of the water gap forms a certain angle with the horizontal direction. The utility model can reduce the impact depth of molten steel in the crystallizer, form a horizontal upward rotational flow, and meanwhile, the side hole can not generate strong impact action on the solidified shell, thereby being beneficial to the upward floating removal of impurities and improving the cleanliness of the molten steel; on the other hand, the temperature of the molten steel in the lower area of the crystallizer is reduced, so that the components and the temperature are uniformly distributed, the central segregation degree of the casting blank is improved, and the quality of the casting blank is improved.

Description

Immersion type water gap for continuous casting of square and round billets

Technical Field

The utility model belongs to the technical field of the continuous casting, a immersion nozzle is used in square, round billet continuous casting is related to.

Background

The submerged nozzle of the continuous casting crystallizer is one of the most important devices for controlling the quality of a casting blank in a continuous casting link, and the geometric structure of the submerged nozzle directly influences the flowing state of molten steel in the crystallizer, the floating removal of impurities and the growth condition of a solidified blank shell. Therefore, the design and optimization of the continuous casting submerged nozzle structure have important significance for improving the quality of casting blanks and reducing the production cost. At present, some high-end steels such as bearing steel, spring steel, free-cutting steel and the like are produced by a large square billet or round billet continuous casting machine, and a straight cylinder type submerged nozzle is generally selected during protective casting. When a straight cylinder type submerged nozzle is adopted for casting, high-temperature molten steel with a certain superheat degree directly enters the interior of the crystallizer at a higher speed, and the impact depth of the molten steel in the interior of the crystallizer is higher, so that the floating removal of inclusions and bubbles wrapped in the molten steel is not facilitated; on the other hand, a high-temperature area in the crystallizer moves downwards, the molten steel temperature of a lower area is higher, the growth of isometric crystals is not facilitated, the center segregation of a casting blank is easily caused, the thickness of a solidified blank shell at the outlet of the crystallizer is influenced, and the possibility of leakage is increased.

In recent years, with the improvement of the quality requirement of people on steel products and the deep research on continuous casting processes and equipment, researchers have proposed continuous casting submerged nozzles with different structures. Chinese patent CN202527702U, "submersed nozzle of large square billet continuous casting crystallizer", the characteristic of this patent is that the submersed nozzle contains symmetrical side opening, the wall all around of side opening is by inside to outside slope, be the loudspeaker form that expands outward to improve the impact depth of molten steel in the crystallizer. However, in the technology, the molten steel flowing out of the side holes can directly impact the solidified shell in the crystallizer, so that the thickness of the solidified shell at the impact point is reduced, the probability of leakage is increased, and simultaneously, rising rotational flow is difficult to form in the crystallizer to promote floating removal of inclusions and bubbles. Chinese patent CN202479461U "submerged cyclone nozzle for continuous casting" is characterized in that a spiral cyclone guide groove is formed on the inner wall of the nozzle, thereby generating the effect of molten steel cyclone in the crystallizer. JP2000237852 discloses a submerged entry nozzle, wherein a plate-shaped swirl vane is arranged in the nozzle, and when molten steel flows through the swirl vane from top to bottom, an upward molten steel swirl is generated in a crystallizer due to the flow guiding effect of the vane. However, the swirl guide groove or the plate-shaped swirl vane of the nozzle has a complicated structure and is difficult to process, and impurities in molten steel are likely to adhere to the swirl guide groove or the plate-shaped swirl vane to cause nozzle clogging.

SUMMERY OF THE UTILITY MODEL

The utility model provides a not enough to prior art exists, the utility model provides a spiral-flow type mouth of a river is used in square, round billet continuous casting, the mouth of a river is at the inside ascending whirl of level that forms of crystallizer, is favorable to the even growth of base shell circumference, and the molten steel of side opening outflow can not produce violent impact to the primary base shell simultaneously. The utility model provides a square, for the continuous casting immersion nozzle of circle base, square, for the continuous casting immersion nozzle of circle base includes: the submerged nozzle comprises a submerged nozzle main body, wherein the submerged nozzle main body is a cylinder with a hole in the center, the top end of a central hole of the submerged nozzle is of an open structure, the bottom end of the central hole of the submerged nozzle is of a closed structure, four nozzle side holes are uniformly distributed in the lower portion of the side wall of the submerged nozzle, the inner wall and the outer wall of each side hole are vertical smooth planes, and the distance between the plane where the inner wall of each side hole is located and the symmetrical plane of the central hole parallel to the plane where the; the outer wall of the side hole is composed of two intersected vertical planes, the flat surface of the outer wall close to the central hole is in the radial direction of the water gap, the plane of the other outer wall is intersected with the plane of the outer wall close to the central hole in an obtuse angle, the obtuse angle ranges from 120 degrees to 135 degrees, the distance between the intersection line of the two intersected planes of the outer wall of the side hole and the wall surface of the central hole of the water gap is in the range of 1/3 degrees to 1/2 degrees of the wall thickness of the water gap, and the angle range between the vertical plane where the inner wall of.

Optionally, the side holes are inclined downward at a certain angle with the horizontal direction, and the side holes form an included angle α with the horizontal direction, which is in the range of 12 degrees to 23 degrees.

Optionally, when casting a square billet or a rectangular billet, the inner wall of the side hole forms an included angle β with the wide and narrow faces of the crystallizer of the square billet or the rectangular billet, and the included angle ranges from 45 degrees to 60 degrees.

Compare with current immersion nozzle, the utility model has the advantages of: the water gap has wide application range, simple structure and easy processing and production; when molten steel flows through a water gap and enters the crystallizer, the molten steel flows upwards to impact a split stream on the rear part of the wall surface of the crystallizer, a horizontal upward rotational flow is formed inside the crystallizer, floating removal and overheating dissipation of impurities are facilitated, the cleanliness of a casting blank is improved, the central segregation degree of the casting blank is improved, meanwhile, as the outer wall of the side hole is composed of two obtuse-angle surfaces, a certain buffering effect is generated on the molten steel, strong impact on a primary solidified blank shell inside the crystallizer is avoided, and uniform growth of a circumferential blank shell is facilitated.

Drawings

FIG. 1 is a top view of the nozzle structure of the present invention

FIG. 2 is a cross-sectional view of the steps shown in FIG. 1A-A

Fig. 3 the installation schematic diagram of the utility model during the square billet casting

α is the angle formed by the side hole and the horizontal direction

β is the angle formed by the inner wall of the side hole and the wide and narrow faces of the square or rectangular billet crystallizer

Detailed Description

As shown in figure 3, the submerged nozzle for the continuous casting of the square and round billets has the advantages that the top end of the central hole of the submerged nozzle is of an open structure, the bottom end of the central hole of the submerged nozzle is of a closed structure, four nozzle side holes are uniformly distributed on the lower portion of the side wall of the submerged nozzle, the inner wall and the outer wall of each side hole are both vertical smooth planes, the distance between the plane where the inner wall of each side hole is located and the symmetrical plane of the central hole parallel to the plane is 0.3 time of the radius of the central hole of the nozzle, the outer wall of each side hole is composed of two intersected vertical planes, the straight plane of the outer wall close to the central hole is in the radial direction of the nozzle, the plane of the other outer wall is intersected with the plane of the outer wall close to the central hole in an obtuse angle, the obtuse angle range is 125 degrees, the distance between the intersection line of the two planes of the outer walls of the side holes and the wall of the central hole is 0.4 times of the wall thickness of the nozzle, the angle range between the vertical plane where the inner wall of the vertical plane of the inner wall of the side hole is located and the vertical plane of the outer wall of the side hole is 40 degrees, the horizontal direction, the side holes are inclined angle, the side holes and the horizontal direction is inclined angle range is 16 degrees, the angle of the horizontal direction, the side holes are inclined angle, the horizontal direction, the angle of the rectangular hole is inclined angle range is 120mm, the rectangular hole.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims (3)

1. The utility model provides a square, for the continuous casting of circle base immersion nozzle which characterized in that, square, for the continuous casting of circle base immersion nozzle include: the submerged nozzle comprises a submerged nozzle main body, wherein the submerged nozzle main body is a cylinder with a hole in the center, the top end of a central hole of the submerged nozzle is of an open structure, the bottom end of the central hole of the submerged nozzle is of a closed structure, four nozzle side holes are uniformly distributed in the lower portion of the side wall of the submerged nozzle, the inner wall and the outer wall of each side hole are vertical smooth planes, and the distance between the plane where the inner wall of each side hole is located and the symmetrical plane of the central hole parallel to the plane where the; the outer wall of the side hole is composed of two intersected vertical planes, the flat surface of the outer wall close to the central hole is in the radial direction of the water gap, the plane of the other outer wall is intersected with the plane of the outer wall close to the central hole in an obtuse angle, the obtuse angle ranges from 120 degrees to 135 degrees, the distance between the intersection line of the two intersected planes of the outer wall of the side hole and the wall surface of the central hole of the water gap is in the range of 1/3 degrees to 1/2 degrees of the wall thickness of the water gap, and the angle range between the vertical plane where the inner wall of.

2. The submerged entry nozzle for continuous casting of square or round billets as claimed in claim 1, wherein the side opening is inclined downward at an angle with the horizontal direction, and an included angle α formed between the side opening and the horizontal direction is in a range of 12 ° to 23 °.

3. The submerged nozzle for the continuous casting of square and round billets as claimed in claim 1, wherein when the submerged nozzle for square and round billets is applied to the casting of square and rectangular billets, the included angle β formed by the inner wall of the side hole and the wide and narrow surfaces of the crystallizer of the square or rectangular billets is in the range of 45-60 degrees.

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