DE3530959A1 - Refractory brick in an intermediate pan with the possibility of introducing gas into the steel manufacturing process - Google Patents

Description

The present invention relates to improvements in a v / erwendeten in the steel-making process tundish, in particular a novel refractory brick for the separation of inclusions in molten steel without productivity b to affect economy and further steel processing.

During the steel making process, tiny refractory particles are left over from the weathering of the Refractory converter lining, as well as metal oxides, which are used in the reaction of the metals in the molten material Steel is created with the atmosphere and is finely distributed in liquid steel. These are particles and metal oxides known as inclusions, which give the finished steel undesirable properties. Therefore, the Eliminating these inclusions is a significant improvement in terms of the quality of the steel represent.

The following procedures are already known in an effort to reduce inclusions in steel:

1. Increase the capacity of the intermediate pan and thereby longer service life of the steel in the ladle, during which the inclusions naturally adhere to the Can settle on the surface of the melt.

2. Equipping the intermediate pan with guide walls and thereby lengthening the aisle through which the liquid steel must flow through the pan, reducing the time for a natural alluvial treatment of the inclusions prolonged will.

3. Addition of a synthetic slag coating to the surface of the liquid steel, which with the Inclusions reacts and binds them with the slag.

4. Introduction of a protective gas through pores (porous plugs) or nozzles, which develops a stirring effect and a conveying effect in the direction of the surface of the liquid steel.
5

Known pores or nozzles are cylindrical or conical formed, which results in a conveying effect limited to the area immediately above them. they are formed as part of the tundish lining and are level with the bottom of the refractory lining. They are protected by a non-porous block, which means that they and the block are not permanent Constituent parts of the lining are, as their lifespan only allows about 1 to 5 melts before they are replaced Need to become. The replacement can only be done by removing all of the steel and slag from the container is removed, this cools and then finally the pores or nozzles with rods or hammers by hand or mechanically removed or freed. It is Hence the object of the invention to increase the effectiveness of the inclusion removal from the liquid steel. Furthermore, the installation and repair times of corresponding devices should be shortened.

The job is done through an in the steel manufacturing process applied porous refractory brick with in its interior encapsulated pipeline released. The refractory stone has a ramp-like surface that deflects the liquid steel flowing on it upwards. The in Inside the stone located pipeline can be connected to a protective gas source and has a number of Openings through which the protective gas gets into the interior of the porous stone.

The upward deflection of the liquid steel flow initially causes the steel with the finely graded inclusions therein to be deflected upwards. The protective gas is introduced along the entire length of the ER b inventive refractory stone. This causes a further conveyance of the steel upwards and results in a protective gas layer over the entire width of the tundish and in the entire cross section above the refractory brick. All of the steel is deflected upwards by the ramp-like surface of the stone and passed through the protective gas layer, whereby more of the finely divided inclusions are carried to the surface of the liquid steel and eventually the slag is absorbed.

The refractory brick can be installed very easily, which takes much less time. It can be installed in a hot pan, without great manual or mechanical effort. This is achieved simply by the fact that the refractory brick is placed on the refractory lining without forming part of the lining.

The invention is explained in more detail with reference to the drawings. Here / own:

Fig. 1 is an elevation of an intermediate pan with the invention Refractory brick

FIG. 2 shows a section along the line II - II in FIG. 1; FIG. 3 shows a section along the line III - III in
Fig. 1 and

4 is a perspective view of a porous refractory brick, which has the features of the invention.

An intermediate pan in general is a large container, the liquid steel absorbs during its manufacture. In Figure 1 to 3 has an intermediate pan 10 side walls and a bottom 14. A refractory lining 16 for the tundish 10 is on the inside of the Side walls 12 and the bottom 14 are provided. A porous refractory brick 18 is on top 19 of the floor lining · set . The refractory brick 18 is independent from the lining 16. In practice, it is fastened by means of grooves and wedges (notches and wedges) in the exchangeable side and bottom lining 16. The grooves and wedges hold the refractory brick 18 in position during operation. He will be removed and replaced during the removal of slag from the Intermediate pan, because it and the side wall and bottom lining are designed in such a way that they are supported by the Intermediate pan can slide freely (flow freely).

As illustrated in Figures 1 to 4, the refractory brick 18 has a ramp-like surface 20, which faces the flow of liquid steel. The surface 20 is sloping or curved in order to to deflect the liquid steel upwards. Like Fig. 2 shows, the refractory brick 18 extends over the entire width of the intermediate pan. A pipe 22 is encapsulated in the refractory brick 18. It runs parallel to the main axis of the refractory brick 18 and thus practically over the entire width of the intermediate pan.

The pipe 22 has a number of openings 23 on its surface.

An impact pad 30 made of suitable fireproof Material is in the direct path of the liquid steel flow, which is passed into the tundish, is provided. The refractory brick 18 does not act like an insulation

only by the deflection of the liquid steel upwards, but also by the formation of a swamp or Accumulation of liquid steel essentially on the surface of the impact buffer 30.

^l > The refractory brick 18 is made of refractory, highly porous material. This creates a permeability for the protective gas emerging from the pipeline 2 2. The composition of the refractory brick material must provide sufficient fire resistance and strength to protect the pipeline 22 and remove inclusions for the duration of the melting sequence. The usual refractory compounds or combinations of alumina, silica, zirconia, zircon, chromium and magnesia will beat yellow, with magnesia and silicon being the most preferred ingredients.

During operation, that directed to the intermediate trough 10 flows liquid steel on the ramp-like surface 20 des Refractory brick 18 too. There the flow of the Liquid steel deflected upwards. The gas flowing out of the pipe 22 flows through the porous refractory brick and occurs on its top off, so that there is a protective gas layer over the entire width of the intermediate trough and in the entire cross-section

2 "? Above the Fouerf est stone. This "Inert gas curtain" 28 is symbolically identified in the drawings. The entire flow of molten steel is deflected upwards by the ramp-like surface 20 of the refractory brick 18. Farther the entire flow of liquid steel must pass through the protective gas layer. By issuing the Upward component and by passing the Flow through the protective gas layer, more of the finely distributed inclusions become the surface of the steel

5'j carried and absorbed by the slag.

As a result, the whole steel making process becomes more productive increased because there are fewer intermediate pans must participate in the rotation principle. A shortened cycle of each tundra results in more Tons of steel per hour, in greater availability the pouring machine and fewer man-hours for the maintenance of the tundish.

In addition to the aforementioned advantages with regard to the inclusion elimination becomes the life of the Intermediate pan is extended and costs are reduced because of the Refractory brick 18 acts as a danun, consequently the the stream flowing into the tundish is melted Steel forms a build-up on the surface of the impact buffer 30. Therefore, the incoming one hits Steeled on this cluster rather than the impact buffers. This makes the heat cycle the Intermediate pan to replace the impact buffer, and significantly reduces the shelf life of the intermediate pan elevated.

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Claims (5)

Λ ». Refractory brick in a tundish with the option of introducing gas in the steel manufacturing process. 1. Porous refractory brick for use in an intermediate ladle in the steel manufacture Jung process, which has a base, side walls and a refractory lining provided on the inside thereof as well as an inlet for the steel supplied and into which protective gas can be introduced,
characterized,
that it can be placed on the top (19) of the refractory lining (16) of the bottom (14) of the tundish (10), that its main axis runs practically over the entire width of the intermediate pan (10), that it has a ramp-like surface (20) for deflecting the flow of steel upwards towards the surface of the molten steel shows that he has a pipeline that can be connected to a protective gas source (22) with a number of openings (23) one closes, from which protective gas can flow into its interior, after which it passes through the porous material of the refractory brick (10) flows and a protective gas layer on the Gesaintbrei te of the tundish (10) and above !> Refractory brick (18) forms. 2. Porous refractory brick according to claim 1,
characterized, that he has a pipe (22) inside includes and a sloping surface for deflecting the liquid steel towards its surface having. 3. Porous refractory brick according to claim 2,
l '> characterized by that the pipeline (22) can be connected to a protective gas source; s and a number of openings (23) has, from which the protective gas can flow into the interior of the refractory brick (18).
20th 4. Intermediate pan / around use in the steel manufacturing process with a bottom, side panels and an interchangeable one refractory lining on the inner surfaces of the floor and side walls and with an inlet device for delivered steel, marked by a porous refractory brick on the surface of the refractory lining (16) with one extending over the entire width of the Zuuischenwanne (10) .50 main axis, which is a ramp-like surface (20) for deflecting the steel flow towards its surface and by a fireproof impact buffer (30) upstream of the refractory brick (18) the surface of the liner is provided, wherein the refractory brick (18) a part of the hitting it Directs the liquid jet to the impact buffer (30), so that an accumulation of liquid steel forms over it. 5. intermediate trough according to claim 4, characterized, that the refractory brick (18) is a pipe (22) encapsulated, which runs parallel to said main axis, is connected to a protective gas quutille and a number of openings (23), from which the protective gas into the interior of the refractory brick (18) flows, wherein the openings (23) guide the escaping protective gas so that these :; up through the porous refractory brick (18) and a *! Protective gas layer over the entire width of the intermediate pan (10) and above the top of the refractory brick (18) forms.