EP0859678B1 - Process and device for closing a tap hole - Google Patents

Abstract

PCT No. PCT/DE96/02133 Sec. 371 Date May 11, 1998 Sec. 102(e) Date May 11, 1998 PCT Filed Nov. 4, 1996 PCT Pub. No. WO97/18050 PCT Pub. Date May 22, 1997A process for closing a tap hole in a metallurgical vessel at least partially filled with a metal melt includes bringing a compressible fire-resistant material to the moth of a tubular closing element, providing a medium that substantially prevents contact between the fire resistant material and the metal melt, passing the closing element through the melt toward the bottom of the vessel, compressing the compressible material against the bottom of the vessel to form a seal between the outside of the closing element and the tap hole below the closing element, and moving a cut off device over the outside of the tap hole, thereby allowing the tap hole to be filled with a pourable refractory compound via the tubular closing element. A device for performing the process for closing a tap hole includes a tubular closing device with a groove at an end bottom facing the bottom of the metallurgical vessel. The open end of the groove also faces the bottom of the vessel and a closed end of the groove includes a compressible material. The sides of the groove are deflectable such that when the closing device is lowered onto the bottom of the vessel, the compressible material contacts the bottom of the vessel forming a seal.

Description

The invention relates to a method for closing a in the bottom of a metallic melt filled vessel, especially for steel Tap opening, with a tubular closing element arranged in the furnace vessel, which is vertically movable to and from the entrance of the tap hole, and one shut-off device and a device arranged below the bottom of the vessel to carry out the procedure.

In the so-called swamp procedure when tapping a metallurgical vessel In the case of steel in particular, locking devices are used with which it it is possible to leave a residue of the molten metal and the slag in the vessel hold back. Such vessels are regularly designed to tilt avoid the closure system being worn by the liquid metal or the slag is exposed.

From DE 34 37 810 is a closure device for a tap hole in Bottom of a metallurgical vessel known in which outside the vessel, in particular a metallic heating furnace, a shut-off device is provided in which a lower shut-off device can be moved from the outside against the tap opening. in the A tube is arranged inside the vessel, which extends from a release position into the Locking position can be lowered and its mouth is against the edge of the Tap hole. In the lowered locking position, pourable filling material becomes brought through the tube into the tap hole.

It is also proposed to close the tube at the bottom and in the Introduce a gas inside, which ensures that the melt through the lower Pipe opening cannot penetrate into the pipe.

The disadvantage of this closure device is the low wear in addition to its high wear Tightness. In rough steel mill operations, it is not just a matter of fact Wash out the entrance to the tap hole, including the aggressive slag and the high melt temperature unevenly destroy the bottom of the Sealing device.

The invention has set itself the goal of a method and a corresponding Device for the repeatable closing of a tap opening of a to create a metallurgical vessel with a long overall life safe shut-off even without tipping the Vessel is possible.

The invention achieves this goal by the characterizing features of Process claim 1 and device claim 6.

According to the invention, a compressible material is on the forehead of the closing element provided for closure when it comes into contact with the bottom of the vessel is compressed in the area of the tap hole.

While driving through the melt, the temperatures between 1500 and 1700 ° C, the sealing material against the effects of Melt and protected from the liquid metal. So according to the invention proposed this compressible used for sealing purposes To produce material from a refractory material and in the mouth groundbreaking inner area provided on the forehead of the locking device Groove. The rest of the interior of the groove is left free and serves as Chamber for a gas used to protect the sealing material when passing through the Melt is kept in this chamber.

This gas can come from a solid or liquid medium that is on the compressible material is brought and gasified under the influence of heat. It can be continuously supplied as a gas in a further advantageous embodiment or a gas is used, which during the residence time of the compressible material in the melt pool, experience has shown that it takes less than 30 seconds, expands when heated and displaces the melt as it expands, its total volume being sufficient for this process all the time maintain.

The overall process of closing is such that the im Upright furnace through the slag and liquid melt the tubular Closing element is guided until it touches the inner wall of the vessel bottom and seals them tightly to prevent the melt from flowing out. At that time it is Tap hole still open, so that the inside of the tubular element and melt or slag in the tap hole leaves the furnace vessel. Then the shut-off device arranged outside the vessel is turned on Slider or a flap, closed. There is now the possibility that Inspect tap hole. This can be done by direct inspection, however done by a camera or an endoscope. Furthermore, by the tubular closing element a tool with which the tap hole can be treated, for example by hitting bears or the like. Moreover can a device, for example a goalie machine, through the tubular Closing element are brought into the tap hole, with which a repair of the Refractory material is carried out. If the tap opening is usable viewed, a free-flowing material is known in the tap hole brought. This serves to protect the shut-off device and to facilitate Pour on after opening the barrier.

In an advantageous embodiment, the head of the closing element is used as Exchange part trained. This exchange part is, if necessary, for one or exchanged several closing processes and with a new sealing lip, i.e. one Groove and the compressible refractory material.

This interchangeable part can have a wall thickness that is significantly larger than that of the remaining tubular closing element.

The walls of the groove have the task of the sealing material during the Protect driving through the melt. If the sealing material, for example, a mat or a molded part made of fibers, the bottom of the has reached the metallurgical vessel, the material of the walls of the groove is said Do not interfere with the compression of the sealing material. A material is an option metallic material, which is designed as a compensator. Furthermore, a metallic material are used, which after passing through the melt, ie in about 15 to 30 seconds, at least softens, melts or chars. For example, one Cardboard are used, which has a sufficient service life and which Charred contact with the melt.

It is also proposed to design the bottom of the groove in such a way that it adapts to the conditions of the entry of the tap hole. The Reason, i.e. the forehead of the interchangeable part, have a conical surface leading to Center axis tapers to a point. But it can also be with knowledge of the entry form of the Tap hole a corresponding shape of the bottom of the groove can be used with the result that the thickness of the later compressed sealing compound, ie the refractory fibers, is kept almost constant. In this way, one particularly high tightness safely achieved.

Figur 1

Einen Schnitt durch das Ofengefäß mit gerader Grundfläche des Verschließelementes

Figur 2

Einen Schnitt mit angepaßter Grundfläche des Verschließelementes

Figur 3

Eine Skizze eines Wechselteils

An example of the invention is set out in the accompanying sketch. Show it

Figure 1

A section through the furnace vessel with a straight base of the closing element

Figure 2

A cut with an adapted base of the closing element

Figure 3

A sketch of an interchangeable part

FIG. 1 shows a section through part of a metallurgical vessel 10 the metallic vessel jacket 11 and the refractory vessel lining 12. Im Vessel bottom 13 is a tap opening 14 is provided, the mouth 16 through a Shut-off device 20 is closed, here by a flap 21.

The tap opening 14 has a refractory lining 17, which in the region of the Entrance 15 may have a conical bevel.

In the metallurgical vessel 10, which can be covered by a cover 19, there is a tubular closing element 31 guided, on the end face 32 a groove 33 is provided. Compressible material F is in the groove interior 34 brought in. In the right part of the closing element 31 is a detachable Connection 36 on the main body 39 attachable interchangeable part 37 is provided.

In the left part of the closing element 31, a bore is provided through which a gas G can be conveyed into the groove area 34 of the groove 33. In FIG. 1, the inner diameter d _{i of} the closing element 31 is equal to or larger than the diameter D _{i of} the tap opening 14.

FIG. 2 shows a metal melt M on which slag S floats, filled metallurgical vessel 10, which is covered by a lid 19 by which the main body 39 of the closing element 31 can be guided. The closing element 31 is held by a support arm 42 which is moved by a displacement drive 41 is vertically movable. Furthermore, the closing element 31 is by a rotary drive 43 rotatable about its main axis l.

A filling funnel 45 is located on the main body 39 of the closing element 31 applied to facilitate the flow of pourable material into the Tap opening 14. There is also a feed 44 for repair compounds, for example the Torkret Masse T.

The head 37 of the closing element 31 is designed as an interchangeable part. On the right On the side of the present sketch, the base 35 is chamfered, the walls 36 are guided axially parallel to the main axis l. On the left side of the picture is the Base area 35 the current state of the entry 15 of the refractory lining 17 reproduced the tap opening 14. The walls 26 are also axially parallel to Main axis l guided.

Between the two shown base surfaces 35 and the respective entry sections 15, the compressible material F is shown how it is deformed and one tight seal between the molten metal M and the tap opening 14 forms.

In FIG. 2, the mouth 16 of the tap opening 14 is through a Shut-off device 20, here can be closed by a slide 22.

In FIG. 2, the inside diameter d _{i of} the closing element 31 is smaller than the inside diameter D _{i of} the tap opening 14.

Figure 3 shows part of the closing element 31, namely the main body 39 and the interchangeable part 37 fastened via a detachable connection 38. In the left half In the picture, the groove 33 has one arranged at a right angle to the main axis 1 Base 35 on and has walls 36 which in the left side as Compensator is formed and in the right side made of cardboard, for example is constructed. In the inner region 34 of the groove 33 is compressible material F intended. A free space is left up to the mouth of the walls 36, in which gas that can accumulate from a liquid or solid medium H after Transition to the gas phase due to heat accumulates.

On the right side of the sketch is the base 35 of the walls 36 having groove 33 arranged obliquely. In front of this sloping base 35 that is compressible material F introduced in the form of a molded part. To the groove 33 is a gas through a bore through the main body 39 and the interchangeable part 37 G feedable.

Position list

10th

Metallurgical vessel

11

Vessel jacket

12th

Refractory lining

13

Vessel bottom

14

Tap hole

15

Taphole entry

16

Taphole mouth

17th

Refractory lining taphole

19th

cover

20th

Shut-off device

21

flap

22

Slider

Locking device

31

Closing element

32

Forehead closing element

33

Groove

34

Groove area inside

35

Floor space

36

Wall

37

Exchange part

head

38

Detachable connection

39

Main body

Carrying device

41

Slider drive

42

Beam

43

Rotary drive

44

Repair mass supply

45

Hopper

S

slag

M

Molten metal

F

Compressible material

G

gas

R

Trickle-shaped refractory material

H

Liquid or solid medium

l

Main axis

d _i

Inner diameter of the locking element

D _i

Tap hole diameter

T

Doorstep mass

Claims (14)

1. A method of closing a tap opening located in the base of a vessel, in particular for steel, filled with molten metal, having a tubular closing element arranged in the furnace vessel, which may be moved vertically to and from the inlet of the tap hole, and a stop device arranged beneath the vessel base
   characterised by the following steps:

   a) prior to each closing procedure, a compressible refractory material is brought to the mouth of the closing element,

   b) immediately prior to immersion in the melt, a medium is provided upstream of the refractory material in the closing direction in an amount which extensively prevents contact between the refractory material and the melt,

   c) during the closing procedure, the mouth of the closing element is conveyed through the melt to close the tap hole and is pressed against the vessel base with such force that the refractory material is compressed,

   d) the stop device outside the vessel is subsequently brought in a known manner to a position in front of the tap mouth and the tap opening is filled with a pourable refractory composition via the tubular closing element.
2. A method according to claim 1,
   characterised in that,
   after placing of the mouth of the closing element on the base of the inner vessel, the closing element is rotated about its central axis.
3. A method according to claim 1,
   characterised in that
   the medium is a gas, e.g. nitrogen.
4. A method according to claim 3,
   characterised in that
   the gas is additionally introduced during passage of the mouth of the closing element through the melt.
5. A method according to claim 1,
   characterised in that
   the medium consists of liquid or solid material which is converted into the gaseous phase under the action of heat when the closing element is immersed in the melt and the gas then lies in a protective manner upstream of the refractory material.
6. A device for closing a tap opening arranged in the base of a metallurgical vessel, which tap opening may be closed from outside the vessel by a stop device and may be filled with a pourable refractory composition, having a tubular closing element which, on the inside of the vessel, may rest against the upper edge of the tap opening and, in a release position, may be displaced so as to release the tap opening, for performing the method according to claim 1,
   characterised in that,

   at the end (32) of the closing element (31), a forkshaped channel (33) is provided, the opening of which is oriented in the direction of the vessel base (13), in that the inner area (34) of the channel (33) including the base (35) is filled with compressible material F

   in that the remaining inner area (34) of the channel may be filled with gas G and

   in that the walls (36) of the channel (33) consist of a material which does not put up any substantial resistance to the pressure of the closing element (31) against the vessel base (13).
7. A device according to claim 6,
   characterised in that
   the material of the walls (36) is metallic and takes the form of an expansion joint.
8. A device according to claim 7,
   characterised in that
   the walls (36) are from 0.3 to 20.0 mm thick and the wall material (36) at least softens under the action of the heat of the melt (S).
9. A device according to one of claims 6 to 8,
   characterised in that
   the head (37) of the closing element (31), including the component comprising the channel (33), takes the form of a replaceable part and may be connected with the main body (39) of the closing element (31) by a releasable connection (38).
10. A device according to claim 9,
    characterised in that
    the wall thickness of the replaceable part (37) is 3 to 10 times the wall thickness of the main body (39) while exhibiting the same internal diameter (d_i).
11. A device according to claim 9 or claim 10,
    characterised in that
    the ratio of the internal diameter (d_i) of the closing element (31) to the diameter (D_i) of the tap opening (14) is d_i:D_i=0.7 to 2.0.
12. A device according to claim 6,
    characterised in that
    the compressible material (F) consists of refractory material, e.g. carbon-containing material, and is constructed from fibres as a mat or as a shaped article.
13. A device according to one of claims 6 to 12,
    characterised in that
    the base (35) of the channel (33) is conically inclined, with the tip pointing towards the main axis (I).
14. A device according to claim 13,
    characterised in that
    the base (35) of the channel (33) has a shape which matches the inlet (15) of the tap opening (14).

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