JP2558364B2 - Plate valve plate slide repair method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for repairing a plate brick for a slide valve, and in the present invention, a plate brick is a bottom plate (upper plate), a slide plate (middle plate).
And the seal plate (lower plate).

Conventional technology As this kind of repairing means, (1) mix the high-alumina refractory material, sodium silicate and graphite lubricant on the sliding surface of the plate (bottom plate and slide plate) removed from the ladle. "Refining method of sliding nozzle plate" (Japanese Patent Application Laid-Open No. 56-109877) and (2) applying a preteau to a molten metal container and then softening or heat it "A method for preventing damage to a sliding surface of a plate in a sliding nozzle device, performing repairs and other necessary treatments" characterized by supplying a damage preventive material or a damage repair material that is liquefied (JP-A-57-152366) Gazette) etc. are known.

SUMMARY OF THE INVENTION However, the method of (1) described above involves applying a sliding surface lubricant to the sliding surface of a plate brick and drying it.
The effect of repair cannot be expected because it does not penetrate into the inside of the microcracks. In the method (2), a refractory aggregate formed by adding pitch or the like or a formed refractory material having pores impregnated with tar or pitch is formed on the sliding surface of the fixed plate or the sliding plate. Although it is to be inserted or embedded in the recess or the through hole (the right column on the upper side of page 3 of the publication), it is unavoidable that the plate becomes structurally complicated, which in turn causes the occurrence of cracks. Be thought

Means for Solving the Problems The inventors of the present invention have developed the repair method of the present invention as a result of various studies and experiments in order to solve the various drawbacks of the conventional method as described above, and the technical configuration of the present invention is as follows. As specified in the claims, after polishing the sliding surface of the repaired slide valve plate brick removed from the slide valve device, the plate brick is impregnated with a pitch or tar to make fine pitch or tar. Fill cracks,
Next, the surface deposits are removed, mortar is rubbed on the damaged parts of the sliding surface and the cracks with openings, and then the sliding surface is smoothed. The method will be described in more detail below.

Plate brick for slide valve (bottom plate,
Since slide plates and seal plate bricks) are used under severe conditions as is well known, these plate bricks generate thermal strain, surface roughness and cracks, and after a certain number of uses, these plates are repaired. , Will need to be replaced. Therefore, after the used plate bricks were separated for the purpose of cost reduction, and for the reusable plate bricks, the sliding surface was polished to correct the strain, and then a fluid carbon-containing substance of pitch or tar was generated. Impregnate into cracks. vacuum·
After the pressure impregnation treatment, a refractory mortar is used to repair a partially remaining damaged portion and a cracked portion having an opening, and restore the function as a plate to obtain a usable plate brick.

By performing such a repair process, the carbon material is hermetically filled (porosity 1% or less) even inside the cracks.
Air leaks essential for slide valves are prevented.

Example The present invention selects after-use products of plate bricks (bottom plate, slide plate, and seal plate) used for slide valves for dandesh, and performs the following repairs for repairable products: (1) Since plate strains of high alumina quality, alumina carbonaceous quality, magnesia quality, etc. generate thermal strain during use, the surface accuracy of the sliding surface is corrected before repairing the method of the present invention.
Perform polishing. This polishing is not done by cutting and polishing until the damaged portion (generally, in the form of a groove in the range where the slide plate slides back and forth in close contact with the bottom plate) is completely removed. Polish the surface by about 0.5 mm (smoothness within 0.05 mm) to secure the required thickness. Therefore, a part of the damaged part (depth of about 1.5 mm or less) may remain.

This is because the pretotes are strongly stressed by heating during use, and thermal strain, cracks and surface damage occur. If these damaged parts are cut and polished until they are completely removed, the plate itself becomes thin and its strength decreases, cracks occur when it is reused, or because it becomes thin, the surface pressure of the sliding surface decreases, This is because there is a risk of intake of air (atmosphere) from the sliding surface portion or a steel leak accident in which molten steel flows out.

(2) Next, air entrainment (the inside of the molten steel is depressurized due to the molten steel discharged from the injection holes of both plates downward at high speed, and air (atmosphere) is taken in from the gaps or cracks in the plates As a preventive measure against steel quality, it is reimpregnated with pitch or tar by a conventional method, and fine cracks (crack width about 0.1 to 0.5
mm) inside.

However, in the case of a crack having a so-called opening with a crack width of about 0.5 mm or more, when the treated plate is taken out from the pitch or tar liquid, the re-impregnated pitch or tar is cooled and shrinks to cause the surface layer portion to shrink. Since it may be concave, it is added to the next step (3).

(3) Further, after rubbing alumina-based or alumina-carbon-based mortar on the damaged part that partially remains on the sliding surface and the cracked part (0.5 mm or more) having an opening, and thoroughly drying it, the sliding surface becomes smooth. To remove unnecessary mortar.

By rubbing the mortar in this way, it is possible to repair the damaged part that partially remains as it is, and also to repair the part where the pitch or the like is contracted and has a concave shape as before.

Further, since the pits and the like filled in the deep part of the crack are covered with the mortar from the surface, the pits and the like do not wastefully flow out during reuse and can be effectively used.

EFFECTS OF THE INVENTION It has been confirmed that repairing by the method of the present invention provides a function as a plate brick and can be used without problems in actual use.

Continuation of front page (56) References JP-A-57-17472 (JP, A) JP-B-60-39730 (JP, B2)

Claims (1)

(57) [Claims] 1. A slide valve plate brick for repairing, which has been removed from a slide valve device, has its sliding surface polished, and then the plate brick is impregnated with pitch or tar to fill fine cracks with the pitch or tar. Then, after removing the deposits on the surface, rubbing and applying mortar to the sliding surface damaged part and the cracked part with the opening, the sliding part is smoothed, repairing the slide valve plate brick Method.