CN108436071B - Spin-flow long nozzle for continuous casting - Google Patents

Abstract

The invention belongs to the technical field of continuous casting, and discloses a spin-flow long nozzle for continuous casting. The spiral flow guide device is a spiral guide rail, and the maximum outer diameter of the spiral guide rail is not larger than the inner diameter of the long water gap. The invention can fully exert the centrifugal effect of rotational flow continuous casting. The invention can disperse the outflow of molten steel into the tundish, reduce the impact depth, increase the upward reflux and facilitate the floating of steel slag. Is beneficial to the production of clean steel. And the residual quantity of molten steel in the ladle can be reduced, thereby being beneficial to energy conservation and emission reduction.

Description

A spinning flow long nozzle for continuous casting

Technical Field

The invention belongs to the technical field of continuous casting, and in particular relates to a self-spinning flow long nozzle for continuous casting.

Background technique

Continuous casting of steel is a process of cooling liquid steel with a certain degree of superheat continuously into a solid ingot with a certain shape through a water-cooled crystallizer. With the application and development of continuous casting technology, especially due to the increasingly high requirements of users for steel quality and the fierce competition in the international market, the quality of continuous casting ingots has received more and more attention. Strictly controlling the cleanliness of molten steel and reducing ingot defects have become important tasks in continuous casting production.

During the continuous casting process, the molten steel flows from the ladle through the ladle shroud into the tundish. The flow rate of the shroud is determined by the opening size of the sliding shroud. The flow rate of the molten steel from the tundish to the crystallizer is controlled by the stopper rod and another sliding shroud system. The molten steel forms an initial shell in the crystallizer and gradually solidifies into a continuous casting slab in the cooling and support roller system below. As the last metallurgical container before the molten steel solidifies, the tundish plays the role of stabilizing flow, diverting, continuous casting connection and secondary metallurgy in the continuous casting process. It is generally believed that the quality of the molten steel in the tundish is closely related to the flow field in the tundish. A reasonable tundish flow field is conducive to the floating removal of inclusions and improving the cleanliness of the molten steel. An unreasonable tundish flow field may cause a series of problems such as slag entrainment, air suction and refractory erosion, thereby greatly reducing the quality of the molten steel and affecting the continuous casting production efficiency. The traditional tundish flow field control technology is mainly achieved by the design of the tundish structure itself and turbulence controllers (such as retaining walls). Another method is to use the design of the ladle shroud to control the inlet stream of the tundish) and further control the flow field of the molten steel in the tundish. The ladle shroud is a material-resistant channel connecting the ladle and the tundish, and plays an important role in the continuous casting process. The inlet stream of the tundish flow field determined by the ladle shroud directly affects the flow characteristics of the tundish inlet area, and then extends to the entire tundish. For this reason, in addition to the traditional straight-cylinder shroud, people have designed new shrouds such as trumpet-type and dissipative-type.

Summary of the invention

The invention discloses a long nozzle which can automatically generate a swirl when molten steel flows through the nozzle, provides a self-swirl long nozzle for continuous casting, gives full play to the effect of swirl continuous casting, is not easy to be blocked, and does not affect the generation of swirl even if a certain section of swirl guide device is broken.

In order to achieve the above object, the technical solution of the present invention is:

A self-spinning flow shroud for continuous casting consists of a shroud and a swirl guide device, wherein the swirl guide device is arranged in the shroud and is a spiral guide rail, the maximum outer diameter of which is not greater than the inner diameter of the shroud.

Furthermore, the swirl guide device is formed by one spiral guide rail or two or more overlapping spiral guide rails.

Furthermore, the spiral guide rail is a variable diameter structure, and the spiral radius gradually decreases from the middle to both ends.

Furthermore, the length of the middle maximum spiral radius area of the above-mentioned spiral guide rail is 1/4 to 3/4 of the total length of the spiral guide rail.

Furthermore, the lower part of the water inlet is configured as a necking structure to facilitate clamping of the swirl guide device.

Furthermore, the swirl guide device is formed by static pressure using refractory materials.

The above-mentioned swirl guide device is made separately and can be directly placed in the long shroud.

The long nozzle of the present invention can satisfy the swirl of molten steel in different directions. If the swirl of molten steel is clockwise, the spiral guide rail of the nozzle structure adopts a clockwise spiral; if the swirl of molten steel is counterclockwise, the spiral guide rail of the nozzle structure adopts a counterclockwise spiral.

The beneficial effects of the present invention are that the centrifugal effect of swirl continuous casting can be fully utilized. The present invention can disperse the outflow of molten steel into the tundish, reduce the impact depth, increase the upward reflux, and facilitate the floating of slag. It is beneficial to the production of clean steel. It can also reduce the residual amount of molten steel in the ladle, which is beneficial to energy saving and emission reduction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of the structure of the spinning flow long nozzle of the present invention

FIG2 is a top view of a long nozzle of a spinning flow;

Figure 3 is a schematic diagram of different forms of built-in swirl guide devices; (a) variable diameter double helical guide rail built-in swirl guide device, (b) variable diameter single helical guide rail swirl guide device, (heat transfer) non-variable diameter double helical guide rail swirl guide device, (d) non-variable diameter single helical guide rail swirl guide device, (e) non-variable diameter multi-helical guide rail swirl guide device.

Detailed ways

The technical solution is described in detail with reference to the accompanying drawings and specific embodiments.

Example 1

The inner diameter of the developed long nozzle is 90mm and the length is 1200mm. The maximum outer diameter of the spiral guide rail of the built-in swirl guide device is 90mm and the length is 1000mm. The length of the spiral guide rail is a non-variable multi-spiral guide rail. The spiral guide rail spirals counterclockwise, and the length of the maximum spiral radius area in the middle of the spiral guide rail is 3/4 of the total length of the spiral guide rail.

Example 2

The inner diameter of the long nozzle is 80mm and the length of the nozzle is 1000mm. The maximum outer diameter of the spiral guide rail of the built-in swirl guide device is 70mm and the length is 700mm. The length of the spiral guide rail is a variable diameter double spiral guide rail. The spiral guide rail spirals counterclockwise, and the length of the maximum spiral radius area in the middle of the spiral guide rail is 1/2 of the total length of the spiral guide rail.

Example 3

The inner diameter of the long water inlet is 50mm, and the length of the water inlet is 800mm; the maximum outer diameter of the spiral guide rail of the built-in swirl guide device is 40mm, and the length is 700mm. The length of the spiral guide rail is a variable diameter single spiral guide rail. The spiral guide rail spirals clockwise, and the length of the maximum spiral radius area in the middle of the spiral guide rail is 1/4 of the total length of the spiral guide rail.

The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims (3)

1. The spin flow long nozzle for continuous casting consists of a long nozzle and a swirl flow guiding device, and is characterized in that the swirl flow guiding device is arranged in the long nozzle and is a spiral guide rail, and the maximum outer diameter of the spiral guide rail is not larger than the inner diameter of the long nozzle; the spiral guide rail is of a variable diameter structure, and the spiral radius from the middle to the two ends is gradually reduced; the rotational flow guiding device is formed by overlapping one spiral guide rail or two or more spiral guide rails; the long nozzle is provided with a necking structure at the lower part so as to conveniently clamp the rotational flow guiding device.

2. A spin-flow nozzle for continuous casting according to claim 1, wherein the length of the intermediate maximum spiral radius area of the spiral guide rail is 1/4 to 3/4 of the total length of the spiral guide rail.

3. A spin-flow nozzle for continuous casting according to claim 1 or 2, wherein the swirl guiding means is formed by hydrostatic forming of refractory material.