JP3858358B2 - Dismantling method of blast furnace hearth contents - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of dismantling the contents of a blast furnace hearth, and more particularly to a method of dismantling the contents of a blast furnace hearth when refurbishing a blast furnace using a furnace ring block dismantling method.
[0002]
[Prior art]
A method called a furnace ring block construction method has been proposed for dismantling and assembling a furnace body during blast furnace repair. As shown in FIG. 2, after the blast furnace body 1 after cooling is cooled, the blast furnace body 1 is horizontally cut into several ring blocks (iron blocks, staves, bricks, etc.) A, B, C, D, and E), and the divided ring blocks A to D are each integrally transported sequentially from the hearth level in the horizontal direction, thereby reducing the time required for on-site construction. This method is attracting attention as a method that can significantly reduce the blast furnace downtime due to blast furnace renovation work.
[0003]
In this construction method, as shown in FIG. 3, the blast furnace furnace body 1 is lifted by a jack 11 attached to a tower 10, and the iron core and bricks of the hearth part are disassembled over the entire circumference, and the residue remaining in the hearth part is left. The firewood 3 can be scraped out by a heavy machine (large civil engineering machine) 4. For this reason, there is an advantage that the construction period for dismantling the contents of the hearth part can be greatly shortened.
In the conventional demolition of a blast furnace at the time of blast furnace refurbishment, the inside of the furnace is usually sprinkled and cooled to near room temperature after the air supply is stopped, and then a part of the iron core on the bottom of the furnace is cut away to form a brick or hearth. It was common to scrape the hearth contents such as the remaining residue 3 and the like. At this time, a large civil engineering machine 4 such as a bulldozer is used to scrape out the contents of the hearth, so the side wall iron notch needs to be large enough to allow these heavy machines 4 to enter and exit. Is limited, it is difficult to use a plurality of heavy machinery 4, and workability is generally not good.
[0004]
In the above-mentioned furnace body ring block construction method, the upper furnace body is lifted upward, so that the iron skin of the entire circumference of the hearth can be disassembled, and heavy machinery can be used from the entire circumference. The workability of material dismantling is dramatically improved compared to the prior art.
[0005]
[Problems to be solved by the invention]
However, at the time of blast furnace renovation, the residue that could not be discharged from the furnace during the blast furnace blowing is usually solidified in the hearth by several hundred to 1,000 tons, especially in the furnace called residue. Since the pig iron has become a strong bullion, it takes time to dismantle. In the conventional technology that cuts out a part of the hearth core and scrapes it out, in order to destroy such a strong metal, there is a means to protect the core notch with a protective wall and blast the contents. Sometimes used. In the furnace ring block method, the iron skin is removed over the entire circumference of the hearth, so in order to adopt the blasting means, a protective wall is installed around the entire circumference in order to avoid affecting the installed equipment. It was necessary to install it, and in reality, the blasting means could not be used. For this reason, means such as fusing with oxygen must be taken for the dismantling of strong bullion, which has become a bottleneck in shortening the dismantling time.
[0006]
The present invention shortens the dismantling time at the time of blast furnace refurbishment by making it possible to implement blasting means in order to efficiently dismantle the solid bullion remaining on the hearth which has been a problem in the above-mentioned furnace body ring block method It is an object to plan.
[0007]
[Means for Solving the Problems]
The present invention relates to the dismantling of the hearth contents in the blast furnace refurbishment using the furnace ring block method, the blast furnace furnace body is lifted upward, the core of the hearth part and the ring carbon are disassembled over the entire circumference, and the hearth part Lowering the furnace body hung upward to a position covering the hearth contents, blasting the hearth contents, lifting and fixing the furnace body again, dismantling and removing the hearth contents, and then cutting the furnace body This is a method for disassembling the contents of the blast furnace hearth.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIG.
Fig.1 (a) shows the state which disassembled the iron core and brick of the hearth part in the furnace ring block construction method. At this time, if there is a strong residue 3 on the furnace bottom 2, it cannot be disassembled by an ordinary heavy machine such as a bulldozer or a giant breaker, and the metal is shredded by fusing with oxygen or the like. However, the dismantling time will be longer.
[0009]
Therefore, after placing the explosive on the bullion, as shown in FIG. 1 (b), the blast furnace body 1 suspended upward is lowered and covered with the residue 3. By doing so, the blast at the time of the demolition blast can be protected by the furnace body 1 without spreading in the lateral direction, so that there is no influence on surrounding auxiliary equipment.
The furnace body has openings such as instrument tube seats, furnace top inlet, and furnace top gas outlet, but the area of the opening is not so large. It is possible to minimize the influence of the blast on the surroundings by opening the lid in advance or setting a discharge port for the blast due to the blast.
[0010]
【Example】
In the renovation work of a blast furnace with an internal volume of 5000 m ³ (hearth diameter 15 m), the hearth ring block method was adopted to dismantle the hearth contents according to the present invention. After dismantling the iron skin of the ring block of the hearth, the brick was dismantled and the slag of the hearth contents was removed from the surrounding three directions. Therefore, 20 kg of explosives was placed in the bullion and the upper furnace body hung upward was lowered to cover the bullion. The seat of the furnace instrumentation tube and the furnace top entrance were closed by a partition plate during the brick removal operation. Of the four furnace top gas discharge ports, two were closed by partition plates, and two were opened as gas vents during the explosion.
[0011]
After the blasting, the furnace body was lifted again and fixed. This blasting crushed approximately 1000t of bullion into small chunks of up to several t, making it easy to disassemble and carry out with heavy equipment such as bulldozers and giant breakers. As a result, the work was completed in 12 days from the start of dismantling the iron ring of the ring block in the hearth to the completion of the contents removal in the hearth.
As a comparative example, a furnace ring block construction method was adopted in blast furnace refurbishment with an internal volume of 4800 m ³ (furnace floor diameter 14.8 m). At this time, about 900 tons of bullion remained in the hearth, and the contents were disassembled while being broken down into several tens of bullion by fusing the bullion with oxygen and crushing the bullion with a giant breaker. It took 19 days from the start of dismantling the iron ring of the ring block of the hearth to the completion of the removal of the contents of the hearth.
[0012]
As a result, the construction period of the present invention was shortened by about 7 days.
[0013]
【The invention's effect】
During the blast furnace renovation, the bottom residue can be efficiently dismantled by blasting.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an implementation state of the present invention.
FIG. 2 is an explanatory view showing a concept of a furnace body ring block dismantling method.
FIG. 3 is an explanatory view showing a state in which an iron skin and a brick of a ring block in the hearth are disassembled.
[Explanation of symbols]
1 Blast Furnace Furnace 2 Furnace Bottom 3 Remnant 4 Heavy Equipment (Large Civil Engineering)
5 Iron skin 6 Brick 10 Yagura 11 Jack

Claims (1)

When disassembling the hearth contents in the blast furnace refurbishment using the furnace ring block method, the blast furnace furnace body is lifted upward, the core and ring carbon of the hearth part are disassembled over the entire circumference and lifted above the hearth part. The furnace body is lowered to a position covering the hearth contents, the hearth contents are blown up, the furnace body is lifted and fixed again, the hearth contents are dismantled and removed, and then the furnace body is cut into rings. Dismantling method for blast furnace hearth contents.

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