RU2507028C1 - Hearth - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Proposed hearth comprises bearing plate, two sidewalls, rear and front walls located thereunder. Hearth walls have the ledge made at top section to extend inside the hearth. Hearth inner surface is composed by concave impact surface of said bearing plate and sidewall wavy surfaces. Wave peaks of hearth section perpendicular to sidewalls are located at concave curve as an circle arc or n ellipse.

EFFECT: localised metal flows and lower turbulence.

4 cl, 5 dwg

Description

The invention relates to the field of metallurgy and can be used, in particular, in the intermediate ladles of plants for continuous casting of steel.

Known shock pad casting device containing a base plate having an upper impact surface surrounded at least partially by a side wall. Passages are made in the wall. Vaulted-step structures surrounding the walkways and / or weir-like walls divide and distribute the exit stream (RU 2280535 dated 05.22.2002, IPC B22D 41/00).

The disadvantage of this product is the occurrence of additional turbulence in the volume of the intermediate ladle due to reflection and countercurrent to the incoming metal due to the absence of a refractory cover for the product, which would contribute to the localization of turbulence in the volume of the product. The lack of localization of turbulence in the volume of the product can lead to the slag of the tundish being pulled into the metal volume and the quality of the continuously cast billet may be deteriorated. Another disadvantage of this product is that the product is held at the bottom of the tundish due to the work of adhesion.

A refractory ceramic component is known that contains a bottom — impact surface and walls, which are inclined at the bottom of the bottom and at the free ends in opposite directions. The metal enters the product through the upper hole, which form the walls (RU 2284246 from 01.08.2003, IPC B22D 41/00).

The disadvantage of this product is the occurrence of turbulence in the upper layers of the metal in the intermediate ladle due to the deviation of the metal stream from the impact surface and the further movement of this jet along the walls of the product, creating a turbulent flow, which helps to draw the slag of the intermediate ladle into the metal volume and deteriorate the quality of the continuously cast billet . Another disadvantage of this product is that the product is held at the bottom of the tundish due to the work of adhesion.

Known shock pad for the intermediate bucket of refractory material, consisting of a base having a shock surface, which when used faces a stream of molten metal, from a wall extending upward from the base around the periphery of the shock surface, one or more parts of the upper part of the wall supporting one or more protrusion that protrude inwardly over the periphery of the base (WO 03082499 of 03/28/2002, IPC B22D 41/00).

The disadvantage of this product is the occurrence of additional turbulence in the volume of the product due to reflection and creation of a counterflow to the incoming metal due to the flat design of the impact surface and the right angle between the impact surface and the walls of the product, which contributes to the rapid destruction of the upper part of the product, after which, due to reflection and creation of a counterflow to the incoming metal, the lack of localization of turbulence in the volume of the product can lead to the pulling of the slag of the intermediate ladle into the volume of metal and deterioration in the quality of continuously cast billets. Another disadvantage of this product is that the product is held at the bottom of the tundish due to the work of adhesion.

Known shock pad, consisting of a wavy surface located on the flow path of molten steel, and a very flat square bottom surface to support the shock pillow, as well as four side surfaces extending between the wavy upper surface and the supporting surface (US 5072916 from 05.29.1990 g ., IPC B22D 11/10).

The disadvantage of this product is the occurrence of additional turbulence in the volume of the intermediate ladle due to reflection and countercurrent to the incoming metal due to the absence of walls of the product that would contribute to the localization of turbulence in the volume of the product. The lack of localization of turbulence in the volume of the product can lead to the slag of the tundish being pulled into the metal volume and the quality of the continuously cast billet may be deteriorated. Another disadvantage of this product is that the product is held at the bottom of the tundish due to the work of adhesion.

Known shock pad for continuous casting of steel, which is any geometric shape capacity with a wavy bottom or bottom covered with grooves. The width of the bottom of the shock pad is greater than the width of the neck, and the neck has a protrusion with respect to the inner side surface. (EP 1232814 dated 11/07/2001 IPC B22D 41/00).

The presence of a wavy surface of the bottom of this product leads to the emergence of additional turbulence and spatter when a jet of metal falls. The absence of a wavy surface of the side walls does not allow the localization of turbulence in the volume of the product. The occurrence of additional turbulence and the lack of localization of turbulence in the volume of the product can lead to an increased wear rate of the product, as well as to the slag of the tundish being pulled into the metal volume and deterioration of the quality of the continuously cast billet. Another disadvantage of this product is that the product is held at the bottom of the tundish due to the work of adhesion.

Known shock pad formed from a refractory material capable of withstanding molten steel, comprising a base used as a shock surface for molten metal, and a side wall extending upward; the specified side wall ends at the upper surface, which is located above the base so that the base and side wall form a receiver for molten metal, and the side wall contains at least one channel (patent EP 2047928A1 from 04.15.2009, IPC B22D 41/00).

The disadvantages of this product are: 1 - a flat impact surface of the bottom of the metal detector, 2 - the right angle between the impact surface and the side wall (including channels), 3 - rectangular or close to rectangular channel profiles in the side wall. The first 2 drawbacks lead to the appearance of additional turbulence in the volume of the product due to reflection and countercurrent to the incoming metal, and the 3rd drawback to the rapid destruction of the channels in the side wall of the product (which also contributes to the 2 first mentioned drawbacks). The lack of localization of turbulence in the volume of the product can lead to the slag of the tundish being pulled into the metal volume, and the rapid destruction of the channels in the side wall of the product can lead to a significant amount of non-metallic inclusions entering the metal, which together can lead to a deterioration in the quality of continuously cast billets. Another disadvantage of this product is that the product is held at the bottom of the tundish due to the work of adhesion.

The aim of the present invention is to improve the quality of continuously cast billets, as well as to increase the stability and manufacturability of the continuous casting process by preventing the slag of the intermediate ladle from being drawn into the metal volume, maintaining a stable distribution of metal flows in the intermediate ladle during casting, and the possibility of increasing the seriality of casting by the “fusion to melting. "

The technical result achieved in the claimed invention is to create localization conditions and reduce the degree of turbulence of metal flows inside the product due to partial mutual damping of the energy of the flows by creating local metal vortices inside the product when part of the jet is deflected back into the incoming metal flow. Also, due to the design of the internal profile of the metal receiver, an increased erosion resistance of the product is achieved, which reduces the rate of non-metallic inclusions entering the metal due to the slowdown of the destruction of the metal receiver during continuous casting.

The specified technical result is achieved by the fact that in the metal receiver containing the base plate, the back, front, made lower than the others, and two side walls of the product located along the periphery of the base plate and having in the upper part a protrusion towards the inner volume, ACCORDING to the invention, the inner surface the product is formed by a concave impact surface of the base plate, wavy side surfaces located longitudinally between the vertical surfaces of the front and rear walls, and Product sectional top waves are located on the concave curve as part of a circle or ellipse.

Outside, the side walls of the product can be made vertically or repeating the internal profile of the side walls of the intermediate bucket.

In order to organize the movement of metal flows in the intermediate ladle, the height of the front wall of the metal receiver can be 0.2-0.9 of the height of the remaining walls.

Also, in order to organize the movement of metal flows in the intermediate ladle, at least one hole can be made in the rear wall of the product.

The advantage of arranging the wave peaks of the inner surface of the side walls of the metal receiver on a concave curve in the form of a part of a circle or an ellipse when the section of the product is perpendicular to the side walls is to prevent the formation of additional turbulence of the metal entering through the upper hole of the product into its internal space. The wave-like surfaces of the side walls of the product, located in the longitudinal direction between the vertical surfaces of the front and rear walls, on both sides of the zone of incidence of the metal stream in the metal receiver, allow the turbulent metal flow to separate into separate local vortices, which are mutually quenched due to their random formation and multidirectional movement . Thus, the product creates conditions for localizing and reducing the degree of turbulence of a metal stream falling into it in its own volume (in the volume of the product).

The metal receiver with side walls vertically made from the outside is freely set to its working position in the volume of the intermediate bucket, while the metal receiver remains stable during operation due to adhesion to the bottom of the intermediate bucket.

A metal receiver with side walls, the external profile of which repeats the internal profile of the side walls of the intermediate bucket, is built into the structure of the intermediate bucket. This eliminates the possibility of displacement of the product relative to the place of impact of the metal stream or the ascent of the product, provides reliable fixation of the metal receiver by fixing the side walls of the product in the working layer of the lining of the intermediate bucket.

The essence of the invention is illustrated by drawings, not excluding other options within the claims of the invention.

On figa and 1b shows two sections of the metal receiver, which are indicated on figv (top view). The metal detector has a base plate 3 with a base 4, two side walls of the product 1 and 1 ′ having protrusions in the upper part towards the inner volume 2 and 2 ′. The base plate 3 has a concave inner impact surface 5. Two side walls from the inside have wave-like surfaces 7 and 7 ′ located in the longitudinal direction between the vertical surfaces of the front and rear walls, and in the product section perpendicular to the side walls, the wave peaks are located on a concave curve in the form of a part of a circle or ellipse 6 (the line 6 indicated in Fig. 1b is imaginary and is indicated to illustrate the relative position of the vertices of the undulating surfaces 7 and 7 ′).

The outer surfaces 8 and 9, as well as 8 ′ and 9 ′ of the side walls of the product 1 and 1 ′, respectively, repeat the internal profile of the surface of the side walls of the intermediate bucket in which the metal receiver is installed. The internal volume of the product is determined by the concave impact surface 5, the wavy surfaces 7 and 7 ′ of the side walls 1 and 1 ′, as well as the internal surfaces of the front and rear walls of the product: 10 and 11, respectively. The product has an opening 12 through which metal must flow.

An axonometric projection of the metal detector is shown in FIG.

Figure 2 shows a diagram of the supply of metal from a steel pouring ladle (not shown) in the metal receiver. The metal receiver is installed by the base plate 3 on the layer of the working lining 13 of the bottom (Fig. 2) of the intermediate bucket (the drawing shows only a fragment of the inner surface of the working lining of the intermediate bucket). The working lining 13 of the intermediate bucket is located on the surfaces 14 and 14 ′ of the metal receiver, reliably securing it.

The supply of metal from a steel pouring ladle (not shown) to the metal receiver is carried out through a refractory metal wire pipe 15 to protect the metal stream from spatter and secondary oxidation. The metal stream 16, opening at a certain angle α, enters the product volume (the incoming metal stream is shown by arrows 17), collides with a concave impact surface 5 and is reflected (reflected metal stream 18) to the center of the incoming metal stream 17. The stream of incoming and reflected turbulence is suppressed by undulating surfaces 7 and 7 ′, which divide the general turbulent metal flow into local vortices 19. The incoming and reflected flows directed towards each other alla mutually cancel each other in the volume of the metal receiver, while turbulent flows do not go beyond the metal receiver. After the turbulence is extinguished, a steady metal flow flows out of the metal receiver first through the front wall 10, and then through the side 1 and 1 ′ and rear 11 walls of the metal receiver, thereby forming metal flows in the intermediate ladle.

It is possible that part of the metal flow will be reflected in the direction of the hole 12 through which the metal should enter, but this part of the flow will be reflected by the protrusions 2, 2 ′ of the side walls, as well as the protrusions 10 ′ and 11 ′, respectively, on the front 10 and rear 11 walls into the internal volume of the product.

Made in accordance with the claimed invention, the product allows you to localize the turbulence inside the product by deflecting part of the jet back into the incoming metal stream and its partial mutual quenching. Improving the quality of continuously cast steel billets is ensured by preventing the formation of additional non-metallic inclusions due to a decrease in the degree of turbulence of the falling jet of liquid steel from the steel pouring ladle into the intermediate ladle, as well as by localizing the turbulence of the falling jet in the volume of the metal receiver. An increase in the stability and manufacturability of the continuous casting process is achieved due to the separation of metal flows into separate local vortices, which are mutually quenched due to their random formation and multidirectional movement. Also, due to the design of the internal profile of the metal receiver, an increased erosion resistance of the product is achieved, which reduces the rate of non-metallic inclusions entering the metal due to the slowdown of the destruction of the metal receiver during continuous casting. The design of the inventive metal receiver provides reliable fastening of the product not only due to the adhesion forces between the product and the bottom of the tundish, but also by fixing the side walls of the product by embedding it in the construction of the tundish (the product actually becomes part of the working lining of the tundish, see figure 2) .

Thus, the goals set by the present invention are fulfilled, the claimed technical result is achieved.

Claims (4)

1. A metal detector containing a base plate, two side walls, a rear wall and a front wall made lower than the rest, which are located along the periphery of the base plate and have a protrusion in the upper part toward the inner volume, characterized in that the inner surface of the metal detector is formed by a concave impact surface of the base plates and wavy surfaces of the side walls, while in the section of the metal receiver, perpendicular to the side walls, the wave peaks are located on a concave curve in the form of a circle or an ellipse. 2. The metal detector according to claim 1, characterized in that the side walls are made vertically or repeating the internal profile of the side walls of the intermediate bucket from the outside. 3. The metal detector according to claim 1, characterized in that the height of the front wall is 0.2-0.9 of the height of the side walls. 4. The metal detector according to claim 1, characterized in that at least one hole is made in the rear wall of the metal receiver.

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