JPH01200191A - Disassembly of refractory lining - Google Patents

Abstract

PURPOSE:To make it possible to carry out to advantage a minimum disassembly totally automatically by dividing a section to be disassembled into three zones and working to disassemble each zone by the conditions of shooting for a water jet which are set up for each zone. CONSTITUTION:A refractory object to be disassembled is divided into three zones, namely an A zone which is in contact with almost no metal scum, a B zone which is in contact with the metal scum and atmospheric air and where especially the contact with the slag becomes a problem, and a C zone which is in contact with the metal scum and where still metal is left sectionally. When disassembling a refractory lining each zone is worked according to the conditions of water jet shooting which are beforehand set for each zone. With this arrangement the refractory lining for a molten metal vessel can be disassembled easily and effectively while the lining is hot, and by setting beforehand proper disassembly conditions according to the section to be disassembled a minimum required disassembly can be made to advantage totally automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for dismantling fireproof linings of furnaces, molten metal containers, etc. used in the steel industry, etc. prior to repair work.

(Prior art) For example, as a molten metal container lined with refractory,
For example, in the steel industry, containers such as tap runners, pig iron mixers, converters, ladles, and tundishes consist of side walls and beds (lower parts).
Each is lined with a refractory material, and most have a permanent lining (permanent lining) and an inner lining (work lining).
It is composed of two layers. Work linings are directly damaged in various ways by high-temperature molten metal (hot metal or molten steel), so the remaining thickness of the work lining becomes thin after use for a relatively short period of time (several days to several months), so relining and repair work must be performed. It won't happen.

In addition, furnaces such as blast furnaces, converters, and electric furnaces are constructed of piled up refractory bricks, and when the remaining thickness becomes thin, the blast furnace is generally repaired to extend its life. When the furnace reaches its final stage, the refractory bricks will eventually need to be dismantled and rebuilt. During this repair work, the lining,
The remaining work lining in the damaged area and its surrounding area, that is, within the repair area, must be demolished, but due to the high temperature of the molten metal and other factors, the refractories of the remaining work lining have become hard and sintered inside and out, forming a rock-like shape. It often transforms into a strong organization.

Therefore, it is not easy to dismantle the remaining work lining, and as a disassembly method, for example,
As shown in Publication No. 9, a method of dismantling by injecting a static crushing agent into the refractory lining, or Utility Model Application No. 58-793
As shown in Japanese Patent No. 14, there is a method of driving a piston with compressed air and dismantling the refractory lining by moving a hammer back and forth. The present inventors also proposed a dismantling method and device using high pressure water (Japanese Patent Application No. 91286/1983,
-91287, patent application No. 1983-99519, patent application No. 1983
No. 2-227758) has already been developed.

Therefore, in such a disassembly method, it is preferable that no humans are involved and the work proceeds under fully automatic control. Demolition work involves harsh environments such as high temperatures and high dust, and considering the aging of workers and the need to save labor, a method to control the above-mentioned demolition technology is needed.

(Problems to be Solved by the Invention) As described above, the present inventors have already developed a method of dismantling a refractory lining using ultra-high pressure water in hot and cold conditions. Hot demolition, which involves thermal spalling and small steam explosions, is far superior to cold demolition. However, in order to carry out complex automatic control, precision equipment such as highly sensitive visual sensors and movable arms are required, and when used in high-temperature environments, equipment such as cooling equipment is required, making it a fairly large-scale device that can be easily installed anywhere. It cannot become a demolition machine that can be used at any time.

An object of the present invention is to set dismantling conditions in advance according to the properties of the refractory lining part to be dismantled, and to dismantle the fireproof lining easily and effectively in a fully automatic manner.

(Means for solving the problem) When dismantling the refractory lining with ultra-high pressure water, in order to obtain suitable impact conditions, distance meters, color sensors, roughness meters, etc. are used to detect the condition of the refractory lining. Various sensors are used for discrimination, but problems remain in installing them directly in a high-temperature atmosphere.

The hardness of the refractory lining surface to be dismantled is determined depending on the material and reaction with slag depending on the part, so if the dismantling conditions are set in advance according to the part, the above-mentioned Thus, dismantling can be done easily and effectively with high precision, without necessarily relying on visual sensors or the like.

The present invention is based on this technical idea and has developed a method for easily and effectively dismantling refractory linings using ultra-high pressure water. A zone, B zone in contact with hot metal slag and the atmosphere, C zone in contact with hot metal slag and some residual metal
This is a method for dismantling a refractory lining, which is characterized by dividing the refractory lining into zones, and disassembling the refractory lining by performing work under preset water jet impact conditions corresponding to each zone.

That is, in the present invention, the refractories to be dismantled are determined in advance by the types of refractories depending on their parts, and the parts that are susceptible to erosion due to contact with hot metal, slag, contact with the atmosphere, residual metal, etc. The lower part is divided into three sections in advance, the most preferable water jet impact conditions are set for each zone, and chisel work is performed for each zone based on the respective set conditions.

Each zone will be explained below.

Zone A is a region that does not normally come into contact with hot metal slag and is mainly exposed to high temperatures in an oxidizing atmosphere. Since there is no contact with hot metal slag, the materials used are low-cost raw materials and contain a large amount of Sin to prevent atmospheric oxidation. Since there are many 5in2 pieces, vitrification progresses during use, and the strength when dismantled is relatively strong.

The B zone mainly has a long contact time with the slag, and is a region where melting loss occurs due to reaction with the slag. The materials used are of high purity so that even if slag enters the pores, the melting point of the material will not drop. Furthermore, by incorporating a large amount of SlO, the slag erosion resistance is improved. Because it is mainly formulated with high-purity raw materials, sintering is not accelerated during use and its strength is relatively weak.

Zone C is a region that has the longest contact time with hot metal slag, and is particularly a region where contact with hot metal slag is the main one. The material used is A1□0. which is resistant to hot metal. A1.0. is oversintered, and the strength is the highest in each zone.

Accordingly, the present invention sets the impact conditions of the water jet depending on the material of the refractory material in each zone, the state of melting and damage, and the remaining state of slag, base metal, etc.

Next, the setting conditions corresponding to each zone will be explained.

The A zone has the least erosion loss and is easy to dismantle due to its material, so the basic conditions for a water jet are, for example, water pressure 1.
It can be easily hung at 500 atm and a distance between surfaces of 50 mm.

Zone B requires the most powerful water jet conditions to remove the reaction layer with the slag. Basically, for example, the water pressure is 2500 atm and the distance between surfaces is 1m! 201 Qm
, it is preferable to climb slowly.

If no bullion is mixed in the C zone, for example, the water pressure is 200.
It is possible to hang at 0 atmospheric pressure and a distance between surfaces of lII2Qmm, but if bare metal is mixed, the water pressure must be adjusted to 2500, for example.
Air pressure, water volume 81/min, nozzle movement speed 0.5 m7
It is preferable to cut the material into abrasive material by simultaneously blowing powder into the material for abrasive cutting.

A concrete explanation will be given below using a blast furnace gutter refractory lining as an example.

The tapped hot metal and blast furnace slag are separated in a large trough due to the difference in specific gravity, resulting in a cross-sectional view as shown in Figure 1. The length of the gutter is approximately 1
0 m, but the cross-sectional properties shown in Figure 1 are almost constant from upstream to downstream. Fireproof lining for gutter is divided into three zones A, B, and C as shown in Figure 1.
As shown in Table 1, each construction was made using different materials.

That is, the A zone is a region that hardly comes into contact with hot metal slag and has relatively little damage, the B zone is a region that mainly comes into contact with blast furnace slag and comes into contact with the atmosphere during pig iron storage, and is the region where the most severe erosion occurs. Zone C mainly comes into contact with hot metal, and even during storage, there are areas that are in contact with hot metal slag, and there are areas where overall erosion loss and some bare metal remain.

Table 1 Materials are selected and constructed as shown in Table 1 to suit each zone A to B-C.

Since the fireproof lining of a gutter will normally wear out considerably if it continues for 10,000 tons, for example, by setting the dismantling conditions shown in Table 2 according to each zone in advance, it is possible to easily and effectively dismantle it fully automatically. Can be done.

Table 2 As with the gutter lining, the materials for the pig iron mixer, pot, etc. are selected to achieve an overall even balance of erosion, taking into account the slag line, hot water contact area, etc. Figure 2 shows a cross-sectional view of the pig iron mixing car, and the A zone, which has almost no contact with the hot metal slag,
Zone B is in contact with hot metal slag and the atmosphere, and contact with slag in particular is a problem, and Zone C7 is in contact with hot metal slag and some residual metal remains. I'm using it.

Table 3 Therefore, by setting the demolition conditions in advance according to each zone as shown in Table 4, it is possible to easily and effectively perform fully automatic demolition.

Table 4 (Example) The fireproof lining of a gutter was constructed using the method of the present invention under appropriate demolition conditions according to each zone shown in (a), (b), and (viii) below (a). The dismantling conditions for zone A in Figure 1 were as follows: water pressure 1500 atm, face-to-face ratio lllll 50 mm, water flow rate 4 cycles/min, nozzle movement speed 3 turtles/min, and a thickness of 15 to 20 m+n could be easily removed.

(b) Demolition conditions for Zone B in Figure 1 Water pressure 2500 atm, face-to-face ratio 11!20 mm, water volume 8/
With a nozzle movement speed of 1 mm/min, a thickness of 25 to 30 mm could be slowly drawn.

(8) Demolition conditions for Zone C in Figure 1 Since there was almost no metal mixed in, the water pressure was 2000 atm and the surface ratio was Ili! 20 mm, a water flow rate of 6 λ/min, and a nozzle movement speed of 2 mm/min, it was possible to sew a thickness of 15 to 20 mm.

The above dismantling conditions are set in advance, and the chipping work is carried out while controlling the high-pressure pump shown in FIG. went.

In addition, when the entire surface is dismantled under the same conditions (Comparative Example-1
) and the case of dismantling with a visual sensor installed in a cold state (Comparative Example-2) are shown in Table 5.
Shown below.

Table 5 Comparative Example 2 was cooled until the refractory lining temperature reached approximately 50°C, and the distance between the surfaces was always 20+n using a laser distance meter.
The water pressure was controlled between 1,500 and 2,500 atmospheres depending on the hardness of the refractory lining while maintaining the pressure at 1,500 to 2,500 atmospheres. The chipping width was approximately 15 mm, and a color sensor was used to determine whether or not a healthy layer had been dismantled. According to this method, only the minimum necessary amount is dismantled, so the amount of repair material can be minimized to 21 tons, but it takes time to cool down, and the demolition ability is lower in the cold than in the hot, so the water pressure must be increased and the nozzle movement speed must be increased. It is necessary to slow down the speed to 0.5 m/min, which is not preferable when compared with the wood-based method.

(Effects of the Invention) As explained above, according to the present invention, the refractory lining of a molten metal container can be easily and effectively dismantled in hot conditions, and appropriate dismantling conditions can be set in advance according to the part to be dismantled. This makes it possible to advantageously carry out the minimum necessary disassembly fully automatically without using visual sensors that are sensitive to high temperatures.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a mode in which the present invention is implemented for dismantling the refractory lining of a large gutter, and FIG. 2 is a partially sectional explanatory diagram of the refractory lining of a pig iron mixer car. 1... High pressure water pump 2... Injection nozzle 3...
・Movable trolley 4...Movable arm 5...Gutter lining Diagram 2

Claims (1)

[Scope of Claims] When dismantling the refractory lining using ultra-high pressure water, the part to be demolished is divided into three zones: A zone that hardly comes into contact with the hot metal slag, a B zone that comes into contact with the hot metal slag and the atmosphere, and a part that comes into contact with the hot metal slag. A method for dismantling a refractory lining, which is divided into a C zone in which bare metal remains, and a C zone in which bare metal remains, and the dismantling is carried out under preset water jet impact conditions corresponding to each zone.