JPS6236064Y2 - - Google Patents

Description

[Detailed description of the invention] This invention allows the charging bucket to run inside the enclosure, thereby eliminating unnecessary openings and preventing smoke leakage from the enclosure when charging raw materials into the arc furnace. The present invention relates to an enclosure for an arc furnace that prevents this, further improves the work environment and work efficiency, and makes it possible to effectively utilize energy in exhaust gas.

In recent years, while the energy situation has worsened, regulations on improving the work environment and preventing pollution have become even more stringent, and the operating environment for steelmaking arc furnaces is extremely harsh.

During the operation of an arc furnace for steelmaking, the smoke and dust generated from the arc furnace significantly deteriorates the working environment.
Therefore, if we try to prevent such pollution by collecting dust from buildings, steel factories have many openings.
Dust collectors suck in a large amount of air in addition to smoke. Therefore,
Since a large amount of air must be exhausted, a large fan is required, which increases equipment costs and operation and maintenance costs. Furthermore, arc furnaces for steelmaking generate loud noises reaching up to 120 dBA, which can cause occupational diseases such as hearing loss.

Therefore, in order to solve the above problems, the entire arc furnace was enclosed in an enclosure to prevent the leakage of smoke and dust, and the noise level was reduced to a level where normal conversation could be carried out.This significantly improved the working environment for general work. Also, it has become possible to reduce the amount of exhaust air by more than half.

To explain such a conventional enclosure with reference to FIG. 1, an enclosure main body a surrounding an arc furnace has an opening b through which a bucket passes when raw materials are introduced into the arc furnace, and a wire for suspending the bucket. An opening c is provided through which the rope passes, and large doors d and e are attached to these openings b and c.

However, the above enclosure has various problems as follows.

The opening b through which the bucket passes is large, and
Since the opening c through which the wire rope passes is located directly above the arc furnace where smoke is generated most intensely, the working environment deteriorates due to smoke leakage when charging raw materials.

To prevent smoke leakage when charging raw materials, either install ducts around openings b and c to absorb smoke with a large air volume, or install air curtains near openings b and c to prevent smoke leakage. However, it is not possible to completely prevent smoke leakage. Particularly when reloading, a large amount of combustible material containing impurities is thrown into the high-temperature furnace, and a large amount of smoke is emitted, causing a large amount of smoke to be blown up by the rising air, making it extremely difficult to prevent this with smoke suction or air curtains. It is.

Since there must be no obstacles in the way of the wire rope suspending the bucket to the top of the arc furnace, the upper beam cannot be passed through point f in Figure 1, so the enclosure is extremely rigid. This is economically disadvantageous because the rigidity of other members must be increased.

It is necessary to pass the bucket accurately through the opening b, and if the operation is incorrect, there is a risk that the enclosure may be damaged due to a collision.

Since it is necessary to move two larger doors compared to a general electric furnace, the operating time is slightly longer.

It is also possible to house the crane itself for transporting buckets within the enclosure, but in this case, even though the opening and door in the ceiling are unnecessary, the door in the side wall would be very large, making it uneconomical. Moreover, it takes time to operate due to the large door, and it is not possible to prevent smoke leakage.

At the final stage of melting and during the refining stage, very high temperature gas is generated, but this gas must be cooled before passing through the bag filter to prevent damage to the bag filter. However, cooling high-temperature gas and discarding the heat in the gas is
Unfavorable from the perspective of energy conservation.

The gas generated from the arc furnace contains a large amount of carbon monoxide gas and is combusted in the air outside the furnace. Therefore, there is a risk of explosion if inhaled directly.

The present invention eliminates the above-mentioned drawbacks of the conventional arc furnace enclosure, completely prevents smoke leakage, has sufficient rigidity, has good operability and work efficiency, and saves energy. It was designed for the purpose of providing a highly safe enclosure for an arc furnace, and has a protrusion on one side and a planar shape of approximately L.
The arc furnace is surrounded by a letter-shaped enclosure body, and a dust collection duct is arranged above the enclosure body, and the material is charged into the arc furnace along both side walls of the enclosure body. A pair of left and right rails are provided on which the beam carrying the charging bucket can run, and when the beam carrying the charging bucket runs on the rails to the end on the opposite side of the arc furnace, the charging bucket is located outside the enclosure main body. One rail is extended to the vicinity of the end of the protruding part of the enclosure main body, and the other rail is extended to the outside of the enclosure main body, so that the beam passes through the part of the wall surface of the enclosure main body where the beam carrying the charging bucket is mounted. An opening that also serves as an air intake port is provided so as not to interfere with running, an opening is provided in the wall of the enclosure main body where the charging bucket passes, and a shutter is provided to open and close the opening so that it can be raised and lowered,
A dust collection elbow is provided on the arc furnace lid so that gas from the arc furnace is introduced into the charging bucket main body when the charging bucket stops at a predetermined position outside the enclosure main body and the shutter is closed. In addition, in addition to connecting the ducts to the charging bucket, the shutter is provided with a small opening that passes through the shutter so that the dust collection elbow of the arc furnace lid communicates with the duct of the charging bucket. , the dust collection elbow is connected to a fixed duct provided at a predetermined position outside the enclosure when closed, so that the gas from the arc furnace preheats the raw material in the charging bucket and then the gas is discharged through the fixed duct; It is characterized by a fixed lid that can be opened and closed.

Embodiments of the present invention will be described below with reference to the drawings.

A dust collection elbow 3 with a horizontal upper end is attached to the furnace cover 2 of the arc furnace 1 installed at a required position, and a beam 6 is placed via wheels 5 on rails 4a and 4b laid so as to extend toward the arc furnace 1 side. A traveling drive device 7 is mounted on the beam 6, and a charging bucket 8 for charging raw materials is fixed so that the charging bucket 8 can travel directly above the arc furnace. A switching device 9 is provided.

A duct 10 is fixed to the lower side of the charging bucket 8 so that it can face the dust collecting elbow 3 at a required distance, and the lid 1 of the charging bucket 8 is fixed.
A dust collecting elbow 12 with a horizontal upper end is attached to the fixed duct 1, and the dust collecting elbow 12 is connected to a fixed duct 1 equipped with a dust collecting fan.
It is configured so that it can be confronted with 3.

The entire arc furnace 1 and rail 4a as well as the rail 4
b is surrounded by the enclosure main body 14 up to a predetermined position, so that raw materials can be loaded into the charging bucket 8 by a crane or the like outside the enclosure main body 14. An opening 15 that also serves as an air intake port is provided so as not to impede the running of the enclosure body 14, and an opening 16 is provided in the charging bucket 8 passing portion of the enclosure body 14, and the opening 16 is connected to the lifting drive device 17. Shutter 1 that can be raised and lowered
8, and an opening 19 is bored in the shutter 18 so that high-temperature gas can be charged into the charging bucket 8 from the duct 3 through the duct 10 during operation, and the arc furnace inside the enclosure main body 14 is opened. 1. Install the dust collection duct 20 directly above. Furthermore, if the leakage of noise from the opening 15 is large, a silencer 21 is attached to the beam 6 to prevent noise.

Next, the operation of the present invention will be explained.

When charging raw materials into the charging bucket 8, the charging bucket 8 is placed at a required position outside the enclosure, the shutter 18 is closed, the lid 11 is opened, and the raw materials are loaded into the charging bucket 8 using a crane or the like (not shown). The raw materials are put in and the lid 11 is closed after being put in.

When the lid 11 is closed, the dust collecting elbow 3 is opened at the opening 1.
9. The charging bucket 8 is connected to the charging bucket 8 through the duct 10, and the charging bucket 8 is connected to the dust collecting fan through the dust collecting elbow 12 and the fixed duct 13, so that the high temperature generated by the operation of the arc furnace 1 The gas is introduced into the charging bucket 8 through the dust collection elbow 3, the opening 19, and the duct 10, where the raw material is preheated to become a low-temperature gas, and then passed through the dust collection elbow 12 and the fixed duct 13 to the outside. is discharged to.

Once the raw materials have been preheated, the shutter 18 is opened and the furnace lid 2 is also opened, the charging bucket 8 is moved together with the beam 6 into the enclosure, and the shutter 1 is opened.
8 is closed, the charging bucket 8 is moved to just above the arc furnace 1, the lower part of the charging bucket 8 is opened, and the raw material is charged into the arc furnace 1. The smoke emitted at this time is
The dust enters the dust collection duct 20 together with the air taken in through the opening 15 and is discharged to the outside.

After charging the raw materials, close the lower part of the charging bucket 8, open the shutter 18, take the charging bucket 8 out of the enclosure, close the shutter 18 and the furnace lid 2,
Open the lid 11 and put the raw material into the charging bucket 8,
The lid 11 is closed and the raw material is preheated with high-temperature gas generated by the operation of the arc furnace 1, and the charging bucket 8 stands by in preparation for the next charging. The raw materials charged into the arc furnace 1 from the charging bucket 8 include scrap, auxiliary raw materials, and the like.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

According to the arc furnace enclosure of the present invention, there is no large opening in the enclosure when charging raw materials, so there is no risk of smoke leakage.
The working environment will become even better.

Since there is no need for an opening for passing the rope on which the bucket is suspended, sufficient rigidity within the enclosure can be achieved with a simple structure, which is economical.

Since erroneous operations that may occur during crane operation are eliminated, there is no risk of the bucket colliding with the enclosure and damaging the enclosure or other equipment, thus significantly improving safety.

Since raw materials can be charged into the charging bucket regardless of the operating state of the furnace, the operating rate of the device can be improved.

Since there is no risk of incorrect operation, raw materials can be reliably charged into the furnace.

Material charging time is shorter and more accurate than with a crane, which improves the operating rate of the arc furnace.
Productivity can be increased.

High-temperature gas generated during the final stage of melting and refining can be used effectively, making it possible to save energy and lower the unit power consumption.

Because heat is absorbed by preheating the raw material, the gas temperature decreases and gas cooling for the dust collector is not required. Therefore, since there is no need to install a cooling tower, equipment costs and operation and maintenance costs are reduced.

The carbon monoxide gas generated has a lower temperature,
It does not burn and is mixed with the gas from inside the enclosure, reducing its concentration, making safe processing possible.
NOx generation is reduced.

Various excellent effects can be achieved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory view of the conventional example, Fig. 2 is an explanatory plan view of the present invention, Fig. 3 is a view taken in the - direction arrow of Fig. 2, and Fig. 4 is a view taken in the - direction arrow of Fig. 3. be. In the figure, 1 is an arc furnace, 3 is a dust collection elbow, 8 is a charging bucket, 10 is a duct, 12 is a dust collection elbow, 1
3 is a fixed duct, 14 is an enclosure body, 15, 16
18 is a shutter, and 19 is an opening.

Claims (1)

[Scope of utility model registration request] The arc furnace is surrounded by an enclosure main body having a protrusion on one side and a substantially L-shaped planar shape, and a dust collection duct is arranged above the enclosure main body, and a dust collection duct is installed on both side walls of the enclosure main body. Along the line, a pair of left and right rails are installed on which the beam carrying the charging bucket for feeding raw materials into the arc furnace can run, and the beam carrying the charging bucket runs on the rails to the end on the opposite side of the arc furnace. When the charging bucket is placed outside the enclosure body, one rail is extended to the vicinity of the end of the protruding part of the enclosure body, and the other rail is extended to the outside of the enclosure body, so that the charging bucket can be located outside the enclosure body. An opening that also serves as an air intake port is provided in the portion of the beam carrying the charging bucket that passes through so as not to hinder the beam's travel, and an opening is provided in the wall of the enclosure main body that passes through the charging bucket. A shutter that opens and closes is arranged to be able to be raised and lowered, and when the charging bucket stops at a predetermined position outside the enclosure body and the shutter is closed, gas from the arc furnace is introduced into the charging bucket main body. In addition, a dust collection elbow is connected to the arc furnace lid and a duct is connected to the charging bucket, and the shutter is penetrated so that the dust collection elbow of the arc furnace lid and the duct of the charging bucket communicate with each other. A small opening is provided in the upper part of the charging bucket, which communicates with a fixed duct provided at a predetermined position outside the enclosure when closed, so that the gas from the arc furnace preheats the raw materials in the charging bucket, and then the gas flows into the charging bucket. An enclosure for an arc furnace, characterized in that a lid to which a dust collection elbow is fixed is attached so that the dust can be opened and closed so that the dust can be discharged through a fixed duct.