JPH04292787A - Electric furnace for manufacturing steel with cleaner of top elbow - Google Patents

Abstract

PURPOSE:To provide an electric furnace for manufacturing steel with a cleaner of a top elbow, in which the elbow can be automatically cleaned, a fear of an operator's accident is eliminated, a labor can be conserved, an efficiency thereof can be enhanced and a removed slag is dropped out of the furnace. CONSTITUTION:This invention provides an electric furnace for manufacturing steel with a cleaner of a top elbow comprising a cleaner 26 having a scraping member 38 disposed telescopically at an open end of the elbow 18 secured to a furnace cover in a state rotated to throw a material by opening the cover 15 to pass discharge gas, thereby automatically removing slag 91 by telescopically moving the member of the cleaner in the elbow.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric furnace for steelmaking equipped with a cleaning device for the furnace top elbow. Generally, in an electric furnace for steelmaking, the exhaust gas that is emitted when melting steel is attached to the furnace lid at an angle, bent horizontally, and discharged through a dogleg-shaped duct commonly known as the furnace top elbow to an exhaust gas purification system. However, the present invention relates to an electric furnace for steelmaking that is equipped with a device that automatically cleans dust contained in the exhaust gas that has adhered to the furnace top elbow.

[0002] Electric furnaces for steelmaking produced, for example, 34 million tons of the 110 million tons of crude steel produced in Japan in 1990, and account for one of the major industries that support the Japanese economy. This electric furnace is a facility that produces high-quality steel by recycling factory waste, scrapped cars, and recovered beverage cans as the main raw materials.

[0003] In the electric furnace, waste scraps are oxidized or reduced and refined, but waste products such as automobiles contain many plastics, fibers, etc. The above flame instantly combusts and turns into dust. Since this dust pollutes the atmosphere, it is required by law to purify it, and the exhaust gas containing this dust is sent to the exhaust purification device through the furnace top elbow. Therefore, this furnace top elbow is 300
As the flame at around 0°C flows, it receives a high thermal load,
It is cooled with a large amount of water to prevent melting and damage, and the inner wall surface is always kept close to the water temperature. Therefore, the dust in the exhaust gas and the substances melted at the high temperature of the exhaust gas are cooled by the pipe wall, harden and accumulate on the pipe wall, and the amount of accumulation increases gradually, narrowing the exhaust gas passage and fulfilling its role. It disappears.

0004

2. Description of the Related Art FIG. 6 schematically shows a conventional electric furnace for steelmaking. In this figure, 10 is the furnace body, and the furnace bottom 12
is made of refractory material, and the furnace wall 13 is water-cooled,
The upper surface is covered with a water-cooled furnace cover 15. Reference numeral 16 indicates three electrodes (only two are shown) made of graphite, and reference numeral 17 indicates a support device that supplies strong electric power to these electrodes and supports them. 18 is a furnace top elbow for discharging exhaust gas to the outside, and is water-cooled. Reference numeral 20 denotes a dust collection duct of an exhaust purification device (not shown). 90 is a raw material for steelmaking made of old scrap iron, etc., and the furnace lid is held at 90° with the electrode 16 pulled up.
It will be rotated and thrown in soon. After that, the furnace lid is closed, the electrode is lowered, and electricity is supplied to proceed with the melting process. Then,
The high-temperature exhaust gas generated during melting is sucked into the dust collection duct of the exhaust gas purification system through the furnace top elbow, but it is cooled by the furnace top elbow and does not accumulate on the first sloping section, but it accumulates considerably on the horizontal section. A large amount of slag 91 is deposited. Unless this slag 91 is removed, steelmaking work will not be possible.

[0005] The inventor of this invention is Japanese Patent Application Laid-open No. 62-2763.
As shown in Japanese Patent No. 93, we proposed a device that automatically cleans the dust collection duct of an exhaust purification device following the furnace top elbow in an electric furnace for steelmaking. However, although this dust collection duct can now be cleaned automatically, no device was used to automatically clean the furnace top elbow. Therefore, in order to manually clean the furnace top elbow, it was necessary to stop the electric furnace, rotate the furnace lid by about 15 degrees, build a scaffolding, and climb up to the electric furnace. However, there is a difference in height of more than 10 meters below the scaffolding, and a misstep could result in serious personal injury. Furthermore, the temperature above the electric furnace is as high as, for example, 50° C., making the work dangerous at high places and at high temperatures, and also having the disadvantage that the efficiency of the electric furnace decreases. Furthermore, most of the removed slag fell into the electric furnace.

[0006]

[Problems to be solved by the invention] This invention can automatically clean the furnace top elbow, eliminate the risk of personal injury, reduce labor, and further improve the efficiency of the electric furnace, and remove the removed slag from the electric furnace. The present invention provides an electric furnace for steelmaking with a falling furnace top elbow cleaning device.

[0007]

[Means for Solving the Problems] The present invention provides an electric furnace for steelmaking at the open end of a furnace top elbow which is fixed to the furnace lid when the furnace lid is opened and rotated to allow raw materials to be introduced, and which allows exhaust gas to pass through. The present invention includes a cleaning device having a scraping member arranged so as to be movable toward the furnace top, and is characterized in that the scraping member of the cleaning device is automatically moved forward and backward into the furnace top elbow to remove slag. The present invention provides an electric furnace for steelmaking with a cleaning device for the furnace top elbow.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In one embodiment of the present invention shown in FIGS. 1 to 5, parts similar to those in the prior art shown in FIG. 6 are given the same reference numerals. With particular reference to FIGS. 1 and 2, the furnace lid 15 is pivotable about an axis 22. As shown in FIGS. In general, the raw material 90 (not specifically shown) is introduced with the furnace lid 22 rotated by an angle of about 70 to 90 degrees, for example, as indicated by α in FIG. After this initial input, power is supplied, and when the material has melted considerably after about 30 minutes, for example, the power supply is cut off, the furnace cover is rotated, and the raw material is supplied again. Normally, raw materials are supplied two or three times for one melting. Reference numeral 23 designates an outlet through which the furnace body 10 is tilted to allow hot water, which is molten steel, to flow out, and reference numeral 25 designates a ladle that accommodates this hot water.

Reference numeral 26 denotes a cleaning device for the furnace top elbow 18, which is arranged so as to face the furnace top elbow 18 when the furnace lid 15 is rotated by a predetermined angle to feed raw materials, as shown by the chain line in FIG. 27 is a pedestal supporting this cleaning device, and 28 is a foundation of this pedestal. The cleaning device 26 is constructed as described below.

That is, referring to FIGS. 3 to 5, 30 is an air cylinder, 31 is a piston rod that moves forward and backward from the air cylinder, and 32 is a fixed cylinder. 33, 35, 3
Reference numeral 6 denotes an extensible member which is accommodated so as to be able to move forward and backward inward from the fixed cylinder and is expandable and retractable. The piston rod 31
When the telescopic member 33 moves forward, the telescopic member 33 connected thereto moves forward by the same length, and the telescopic members 35 and 36 further move forward twice and three times as much. 38 is the telescopic member 3
This is a scraping member consisting of a slightly stiff wire brush provided so as to protrude from the 6. This scraping member is attached to each telescopic member 33.
, 35, and 36 repeatedly expand and contract, they enter the furnace top elbow 18 and scrape off the slag 91, causing it to fall from both sides.

The telescopic movement of the telescopic members 35 and 36 is performed as follows. That is, the telescopic member 3
A sprocket 40 is attached near the tip of the sprocket 3, and a chain 41 is attached to the sprocket 40, which has one end connected to the rear end 32a of the fixed cylinder 32 and the other end connected to the rear end 35a of the telescopic member 35. There is. Further, a sprocket 42 is installed near the tip of the telescopic member 35, and one end is attached to the sprocket 42 near the distal end of the telescopic member 35.
A chain 43 is connected to the rear end 33a of the telescopic member 3 and the other end thereof is connected to the rear end 36a of the telescopic member 36. Therefore, the telescopic member 33 is moved by the air cylinder 30 for a distance d.
When the chain 41 moves forward by a distance d, the telescopic member 35 moves forward by a distance d relative to the telescopic member 33, and thus moves forward by a total of 2 d relative to the fixed cylinder 32. Similarly, the telescopic member 36 moves forward by 3d with respect to the fixed cylinder 32.

Further, a sprocket 45 is installed near the rear end inside the telescopic member 33, a part of which comes out through a notch 46 made in the telescopic member, and one end is attached to the fixed cylinder. A chain 47 is mounted, which is connected to the distal end 32b of the body 32 and whose other end is connected to the distal end 35b of the telescopic member 35. Further, there is a sprocket 48 near the rear end inside the telescoping member 35, a part of which comes out through a notch 50 made in the telescoping member, and one end is connected to the telescoping member 35.
A chain 51 is mounted, the other end of which is connected to the tip 33b of the telescopic member 36, and the other end is connected to the tip 36b of the telescopic member 36. Therefore, when the telescopic member 33 retreats by a distance d from the extended state, the telescopic member 35 retreats by a distance d, which is more than the telescopic member 33, by a total of 2d. Similarly, the telescopic member 36 is moved back by 3d. Further, each chain is always maintained in an extended state without sagging.

The cleaning device 26 is controlled by a computer or the like so that the air cylinder 30 automatically moves back and forth when the furnace lid 15 is rotated by a predetermined angle to feed raw materials. Therefore, the furnace top elbow 18 can be constantly cleaned and the accumulation of slag 91 can be completely prevented. In addition, in this invention, the number of extensible members may be increased or decreased as appropriate. Further, the furnace top elbow 18 may be cleaned every other time, for example, instead of being cleaned every time raw materials are supplied.

[0014]

[Effects of the Invention] Since the present invention is constructed as described above, the furnace top elbow 18 can be completely automatically cleaned and the accumulation of slag 91 can be prevented, thereby eliminating the risk of personal injury to workers. And it becomes possible to save labor,
This has the effect that the efficiency of the steelmaking electric furnace is increased, and the removed slag can be discharged outside without entering the furnace again.

[Brief explanation of the drawing]

FIG. 1 is a plan view schematically showing an embodiment of the present invention.

FIG. 2 is a side view thereof.

FIG. 3 is a side view showing a cleaning state of the cleaning device, partially in cross section.

FIG. 4 is a front view showing a scraping member of the cleaning device.

FIG. 5 is a cross-sectional view of the telescopic member of the cleaning device.

FIG. 6 is a longitudinal sectional view showing a conventional electric furnace for steelmaking.

[Explanation of symbols]

10 Furnace body 15 Hearth lid 16 Electrode 18 Furnace top elbow 26 Cleaning device 33　Extensible member 35 Expandable member 36 Expandable member 38 Scraping member 91 Slag

Claims (1)

[Claims] [Claim 1] The furnace lid of an electric furnace for steelmaking is fixed to the furnace lid when rotated to the state where the furnace lid is opened and raw materials are introduced, and is arranged so as to be movable toward the open end of the furnace top elbow that allows exhaust gas to pass through. A furnace top elbow cleaning device comprising a cleaning device having a scraping member, the cleaning device automatically moving the scraping member of the cleaning device forward and backward into the furnace top elbow to remove slag. Electric furnace for steelmaking.