JP3162610B2 - Arc furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc furnace for melting and refining metals using arc heating.

[0002]

2. Description of the Related Art A conventional arc furnace used for melting and refining a metal will be described with reference to FIG. An opening 2 for charging a raw material 9 such as scrap is provided on the upper surface of the furnace body 1, and the through hole 5 of the movable electrode 4 and a peripheral portion are formed in a central portion covering the opening 2 when the raw material 9 is melted and refined. A furnace lid 3 having a duct 6 for sucking exhaust gas is disposed in a removable manner. A water-cooling box 7 or a brick (not shown) for protecting the furnace body 1 from the radiant heat of the arc is provided on the inner surface of the furnace body 1, and the bottom where molten metal is stored is lined with a refractory 12.
Further, an annular reinforcing member 8 for securing strength is provided at an upper portion of the outer surface of the furnace body 1.

In the above-described conventional arc furnace, the furnace body 1, the water-cooled box 7 or the brick, and the annular reinforcing member 8
When the raw material is charged by opening the furnace lid 3 on the upper surface of the furnace, the spilled raw material 9 does not enter the furnace, but deposits 10 such as flash and dust generated during the refining, melting and refining of the spilled raw material 9 are deposited. A gap 11 is formed between the body 1 and the furnace lid 3, and a large amount of outside air is sucked into the furnace body 1, so that the melting efficiency is reduced,
There has been a problem that the exhaust gas suction capacity in the lower part of the furnace is reduced, so that gas and dust scatter from the furnace body 1 to the outside, thereby deteriorating the working environment. Therefore, the gap 11 between the furnace body 1 and the furnace lid 3
As a method of preventing the occurrence of
No. 97 proposes an arc furnace in which a sealing mechanism is interposed between a furnace body upper surface and a furnace lid outer periphery.

[0004]

However, in an arc furnace in which the above-mentioned sealing mechanism is interposed, a deposit 1 such as a raw material, splash, dust, etc.
Even if 0 accumulates, airtightness in the furnace can be ensured. However, as the sediment 10 increases as the melting and refining operations are repeated, the furnace lid 3 rides on the sediment 10 and the sealing mechanism does not operate. There is a problem that airtightness in the furnace can be ensured. In addition, in order to secure the airtightness in the furnace, there is also a problem that the operation of periodically removing the deposit 10 on the upper part of the furnace body 1 must be performed under a high temperature and dangerous condition with the furnace lid 3 opened. Occurs. An object of the present invention is to prevent the gap 11 between the furnace body 1 and the furnace lid 3 for a long period of time without performing the work of removing the deposit 10 on the upper part of the furnace body 1 and improve the airtightness in the furnace. An object of the present invention is to provide a secure arc furnace.

[0005]

In order to solve the above-mentioned problems, an arc furnace according to the present invention has a furnace body having an opening for charging a raw material such as scrap on an upper surface, and covers the opening. In an arc furnace provided with a furnace lid having an electrode through hole in a central portion, a top plate that is circumferentially divided and tiltable in the furnace direction is disposed at an upper circumferential end of the furnace body. An arc furnace in which a seal portion is formed between the upper surface of the furnace and the lower surface of the furnace lid.

[0006]

Since the arc furnace of the present invention has a tiltable top plate around the upper end of the furnace body, raw materials, splash, dust and the like do not accumulate on the top plate. As a result, there is no gap between the furnace body and the furnace lid for a long period of time, no outside air flows into the furnace, high melting efficiency can be obtained, and scattering of gas and dust to the outside can be prevented. .

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an arc furnace according to a first embodiment of the present invention, FIG. 2 is a plan view of the arc furnace according to the first embodiment of the present invention, and FIG. 3 is a detailed view of a portion A in FIG. Note that the same components as those of the conventional arc furnace shown in FIG. One end of the upper part of the furnace body 1 is connected to the annular reinforcing member 8 via a pin 15 and the other end of the outer periphery is connected to a driving device 16 such as a cylinder attached to the annular reinforcing member 8 or the furnace body 1 via a pin 17. Water-cooled top plates 13a and 13b are provided so as to maintain sufficient strength against radiation heat of the arc so as to be connected. The top plates 13a and 13b are divided in the circumferential direction, and can be tilted so that the sediment is dropped into the furnace by pushing and pulling the outer peripheral end by the driving device 16.

The tilting operation of the top plates 13a and 13b is performed by, for example, starting to tilt the top plate 13a first and then slightly delaying the top plate 13b so that adjacent top plates do not interfere with each other when tilting. The top plate 13b is controlled to be tilted and to stop the top plate 13b at a tilt angle θ smaller than the tilt angle of the top plate 13a. Although FIG. 2 shows a case where the number of divisions of the top plates 13a and 13b is eight, the number of divisions is
Is appropriately determined depending on the size of the furnace body 1 so as not to hinder the tilting. A water-cooling box 7 installed on the inner surface of the furnace body 1 to protect the furnace body 1 from the radiant heat of the arc has raw materials, splashes, dusts, and the like deposited on the upper surface thereof.
In order not to hinder the tilting of a and b, the upper surface is inclined so as to lower the inside of the furnace.

With the above configuration, the top plate 1 is supplied by inputting the raw materials 9 for the operation of the previous charge and the operation of the next charge.
The sediment 10 remaining on the upper surfaces of the tops 3a and 3b is removed by tilting the top plates 13a and 13b before closing the furnace lid 3 to start operation, and the top plates 13a and 13b are always flat. And the seal between the furnace lid 3 and the top plates 13a and 13b is always maintained in a good state. Further, when the furnace lid is closed, the top plates 13a and 13b are placed on a seal ring 14 provided over the entire circumference of the annular reinforcing member 8, and the top plates 13a and 13b and the annular reinforcing member The airtightness in the furnace is ensured without any gaps between the furnaces 8.

FIGS. 4 and 5 are a plan view and a detailed view, respectively, of a second embodiment of the present invention. The same components as those in FIGS. 2 and 3 are denoted by the same reference numerals and description thereof is omitted. The top plate provided on the upper part of the furnace body 1 described in the first embodiment includes the pins 15 and 17.
The upper side plates 13a 'and b' are connected to the annular reinforcing member 8 and the driving device 16 through the upper plate 13a 'and the upper side plate 13a' and b 'via the pin 18, respectively. , B ". The tips of the furnace inner top plates 13a "and 13" are in operation, that is, the upper
3a 'and b' rest on the upper surface of the water-cooled box 7 when they are placed on the seal ring 14, and splashes and dust generated in the furnace during operation are reduced to lower portions of the upper top plates 13a 'and b'. Prevent entry.

When the sediment 10 is dropped by tilting the upper top plates 13a 'and b', the furnace inner top plate 13a ",
The tip of b ″ is pushed out to the inside of the furnace so as to slide on the upper surface of the water-cooling box 7, so that it functions as a scraper and the deposit 10 on the water-cooling box 7 can be reliably removed. In the example, the removal of the deposit 10 described in the first embodiment can be performed more reliably and stably, and the airtightness in the furnace can be sufficiently ensured.

[0012]

According to the present invention, the following effects can be obtained. (1) Since the upper part of the furnace body is provided with a tiltable top plate to remove deposits, a sufficient seal between the upper part of the furnace body and the furnace lid is always ensured, and the airtightness in the furnace is maintained. Can be secured. (2) As described above, airtightness in the furnace can be secured.
Melting efficiency is improved, and energy can be reduced. Further, the lowering of the exhaust gas suction capacity in the lower part of the furnace can be prevented, and the scattering of gas and dust is eliminated, so that a favorable working environment can be maintained. (3) Since the sediment can be automatically removed by providing a tiltable top plate at the upper part of the furnace body, there is no need to periodically perform the sediment removal work under high temperature and dangerous conditions. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an arc furnace according to a first embodiment of the present invention;

FIG. 2 is a plan view of the arc furnace according to the first embodiment of the present invention,

FIG. 3 is a detailed view of a part A in FIG. 1,

FIG. 4 is a plan view of a second embodiment of the present invention,

FIG. 5 is a detailed view of a second embodiment of the present invention,

FIG. 6 is a longitudinal sectional view of a conventional arc furnace.

[Explanation of symbols]

 1 Furnace 2 Opening 3 Furnace lid 4 Movable electrode 5 Through hole 6 Duct 7 Water-cooled box 8 Annular reinforcing member 9 Raw material 10 Deposit 1 1 Gap 1 2 Refractory 1 3 a, b Top plate 1 3 a ', b' Upper top plate 13a ", b" Furnace inner top plate 14 Seal ring 15, 17, 18 pin 16 Drive unit

Continued on the front page (56) References Japanese Utility Model Hei 6-51791 (JP, U) Japanese Utility Model 62-41189 (JP, Y2) Japanese Utility Model Utility Model 62-37105 (JP, Y2) (58) Field surveyed (Int) .Cl. ⁷ , DB name) F27B 3/08-3/28 F27D 1/18 F27D 7/06

Claims (1)

(57) [Claims] 1. An arc furnace having a furnace body having an opening for charging raw materials such as scraps on the upper surface and a furnace lid having an electrode through hole in a central part covering the opening. An arc furnace having a top plate that is divided in the circumferential direction and that can be tilted in the furnace direction at the upper end of the circumference, and a seal portion is formed by an upper surface of the top plate and a lower surface of the furnace lid.