FI111188B - Method and apparatus for partial reconstruction of a wall lining for a steel sideboard - Google Patents

Description

111188

Method and apparatus for the partial remodeling of a steel casting wall liner Förfarande och anordning för partiell reconstructing av väggfodring 5 för en stälskänk

The present invention relates to a method for producing a refractory lining in the upper zone of a wall of a steel bucket or similar metallurgical vessels for casting and treating steel and to an apparatus for carrying out this method.

The structure of the fire-resistant lining of metallurgical vessels usually comprises a duration-15 and a work-lining. For permanent lining, refractory bricks or insulating bricks are usually attached in one or more layers to the steel sheath inside the vessel. A working liner is then fixed over the permanent liner, which subsequently comes into contact with the molten steel pulp and wears away due to erosion, in particular the movement of the metal pulp, and chemical corrosion, in particular slag floating on the molten steel pulp 20.

The work liner can be made of fire-resistant brick or it can be formed as a fire-resistant mass which hardens into a monolithic layer. Combinations of both lining methods are also possible.

25

From an economic point of view, taking into account both material costs and durability, as well as lining times and requirements for workers, monolithic lining is often a better solution than masonry lining.

Modified methods associated with modern steelmaking lead to increased demands on the fire-resistant lining of castings. In particular, after the transition to continuous rod casting, higher lowering temperatures and longer residence times of molten steel mass in the bucket have resulted in greater wear resistance of the fire resistant liner.

Because wear is usually different in different wall and bottom areas of the bucket, the liner 5 is often divided into zones containing different thicknesses for the liner and / or different fire-resistant liner types.

After several refills and emptying of the bucket, the work liner is either completely broken at the end of the bucket's journey and replaced or repaired in the event of only partial wear on the 10 zones. When the top of the bucket is covered with a chemically corrosive slag layer approximately one meter from the top of the liner, the liner in this slag zone must be repeatedly broken during replacement of the bucket and replaced or repaired accordingly.

For the new liner, a device is known from SU-A-178955 for sealing the fill mass to the bucket walls by means of radial clamps using retractable and height adjustable model rings.

20 A cladding method is also known for lining steel castings using fire-resistant concrete. For wall cladding, a template is needed to form the internal contour of the pre-concreted cladding. The concrete mass is cast into the ring space between the permanent liner and the template.

25 For complete re-lining, use a template that extends from the bottom of the bucket to the top. For technical reasons, it may be divided into its central part. The casting operation is usually carried out using a mixer, pump and internal vibrator. For example, a three hour casting operation must be performed continuously to avoid possible hardening of the surface. Vibrators prevent the formation of hollow spaces and cavities to achieve good sealing. For example, when the concrete mass is set after 24 hours, the molds can be pulled out again.

3, 111188

In connection with the monolithic lining of the entire wall of the Sango, it has been found to be detrimental that, in the event of rapid wear of the slag zone, the intermediate repairs in this area are so difficult that this area must subsequently be brick fired in Stahl u. Eisen Special, October 1992, as described.

5

It is therefore an object of the present invention to provide a monolithic lining steel casting and treatment barrel in an economically advantageous manner by reconstructing the upper zone of the wall area with a fire resistant mass.

ir 10 This object is achieved by sealing the gap between the lower end of the template and the liner below the area to be remanufactured by blowing tubular sealing material which is relieved of tension before the template is removed.

In this case, it is advantageous that the upper liner does not need to be completely broken. Also, no special equipment is required for surface treatment, but steel scraps and other adhered components can be adequately removed by a conventional disassembly machine which includes a flat-blade chisel. Lining times and material requirements are less than with complete lining breakage and 20 bricks lining. The permanent liner below is not damaged.

The device for carrying out this method is implemented as set forth in claims 2 and 4.

The invention will now be described in more detail with reference to Figures 1 and 2.

Figure 1 is a schematic view of a steel sheath (1), a permanent liner (2) and a work liner (3) and (4). The liner in the lower region (3) still has sufficient thickness. Instead, the liner in the upper region (4) is worn out so that 30 buckets can no longer be used. The liner in the upper region (4) has already been cleaned of steel debris and other adhered components. Place the template (5) in the bucket from above. An inwardly displaced ring 4 111188 (6) is attached to the underside of the template. Attached to the ring (6) is a tubular sealing piece (7) made of resilient material that can be blown. It may also be made of a plastic-reinforced rubber. For protection against damage, a protective sheath (8) is provided between the liner (3) and the sealing piece (7), which is secured at its upper edge, for example, by 5 latches to the lower edge of the template (5). It is made of a tear-resistant flexible material and cut so as to exert prestressed pressure on the sealing member (7).

i

After inserting the template, the sealing piece (7) is blown, whereby it is seated tight against the lining of the lower region (3) in the transition area of the lining in the upper region (4).

The template is then ready to repair the liner in the upper area (4) by post-casting the fire-resistant casting compound into the space between the residual liner and the wall of the template (5).

Figure 2 shows the situation after the completion of the remedy. The tubular sealing piece (7) is no longer under pressure. The protective sheath (8) no longer rests against the liner in the lower region (3) but, due to internal biasing 20, clamps the tubular sealing piece (7) against the ring (6) at the bottom of the template. The template can now be pulled up without damaging the sealing piece (7) or the re-molded liner in the upper area (4).

Claims (4)

A method of re-making a refractory liner in the upper zone of the wall area of a casting and treating ladle by casting a refractory casting material in the space between a template (5) and the resilient working liner (4), characterized in that the gap between the lower end of the stencil (5) and the working liner (3) below the area to be made reseal are sealed by inflating a hose-shaped sealing body (7) and removing the tension in the sealing body (7) before removing the stencil (5). 10 2. A device provided with a stencil (5) and with a mixer, a pump, and an internal vibrator for carrying out the method according to claim 1, characterized in that an inlet for the lower end of the stencil (5) is provided. -shaped ring (6), on whose outer circumference a hose-shaped inflatable sealing body (7) is attached. Device according to claim 2, characterized in that an elastic protective sheath (8) is attached to the lower end of the stencil (5), which surrounds the sealing body on the outer side. 20 4. Device according to claim 3, characterized in that the elastic protective sheath (8) presses the tensionless sealing body (7) against the inset displaced ring (6). 25