JPS58136981A - Method of collecting dust of arc furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention significantly reduces dust collection power, extends the life of the small ceiling,
This invention relates to a dust collection method for an arc furnace that aims to reduce the amount of consumption of graphite electrodes.

To explain a conventional arc furnace with reference to Fig. 1, 1 is a furnace wall, 2 is a working opening provided below the furnace wall, 3 is a tapping port also provided below the furnace wall, 4 is a furnace lid, and 5 is a furnace wall. A graphite electrode 6 inserted into the arc furnace through the furnace lid 4 is a duct connected at one end to the furnace lid 4 and at the other end to a dust collector.

However, when the temperature inside such an arc furnace is high, the furnace body generates natural ventilation and acts as a chimney.

Therefore, when the suction of the dust collector is weak, air (outside air) is sucked from the tapping port 3 and working port 2 at a low location, and high temperature Furnace gas blows out into the atmosphere. Dust collector @1 must suck in enough cloudy gas to prevent blowouts from these high places, so the amount of outside air sucked in from low places (tapping port 3, working port 2) increases significantly. . Therefore, a large amount of outside air is needlessly sucked in, which not only cools the inside of the furnace, but also increases the amount of suction required by the dust collector.
Power consumption is increasing and power costs are increasing. Furthermore, when the high-temperature furnace gas blows out from the electrode penetration part 7, the graphite electrode 5 and the furnace lid 4 are also exposed to the high-temperature gas.
The amount of consumption increases, and the life of the bricks in the small ceiling portion 4a of the furnace lid 4 is shortened.

The present invention features a jib provided around the electrode penetration part and the furnace lid contact surface.
A sealing gas such as air or nitrogen gas is supplied to the seal chamber, and the pressure inside the sealing chamber is kept at the same level as the pressure inside the furnace. By preventing the above-mentioned metal from blowing out into the atmosphere, the amount of outside air flowing into the furnace from the tapping port 3 and working port 2 is reduced, reducing the amount of suction required by the dust collector, thereby reducing power consumption. The seal gas supplied to the seal chamber cools the small ceiling part of the furnace lid to extend the life of the small ceiling part, and the seal gas in the seal chamber cools the graphite electrode to the bottom. The aim is to reduce the consumption of

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

FIGS. 2 and 3 show an embodiment of the present invention, in which a seal chamber 9 is disposed around the outside of the furnace of the Kurofune electrode 5, which is penetrated through the small ceiling part 4a of the brick structure of the furnace cover 4. The chamber 9 is communicated with the furnace interior 11 through the electrode penetration gap 10, and a refractory bushing 12 is attached to the upper surface of the seal chamber 9. and refractory bushing 1
2, and a blower is connected to the other end of the duct 14, one end of which is connected to the seal chamber 9.
Connect 15.

During operation of the arc furnace, a dust collector (not shown) is driven to exhaust gas in the furnace through the duct 6, and a blower is operated.
15 is driven to feed outside air or a sealing gas such as nitrogen gas into the sealing chamber 9, so that the pressure inside the chamber 9 is equal to or higher than the pressure inside the furnace 11. Therefore, part of the sealing gas leaks into the furnace 11 from the electrode penetration gap 10, and the other part leaks into the atmosphere from the electrode penetration gap 13. For this reason, the seal chamber 9 is always filled with seal gas having a low temperature, and the furnace gas having a higher temperature than the furnace interior 11 does not enter the seal chamber 9.

Therefore, since only a small amount of outside air enters the furnace 11 from the work opening 2 and tapping opening 3, the amount of exhaust gas from the duct 6 can be reduced, and the power of the dust collector can be significantly reduced.

Moreover, the small ceiling part 4a of the furnace I4 is cooled from above by the seal gas in the seal chamber 9, resulting in a long life.Similarly, the graphite electrode 5 is also cooled down to the bottom of the small ceiling part 4 by the seal gas in the seal chamber 9. consumption is reduced. Further, since the seal gas having a low temperature is always fed into the seal chamber 9, the seal chamber 9 itself does not need to be particularly water-cooled.

FIG. 4 shows another embodiment of the present invention, in which a seal chamber 16 is provided not only at the electrode penetration section 1 of the small ceiling section 4a but also at the furnace lid contact surface 8. By setting the pressure in the seal chamber 9.16 to a predetermined differential pressure, the amount of air forced into the furnace 11 (or gas I) can be reduced to the minimum, and the dust collector can be Power savings can be measured.

FIG. 5 shows still another embodiment of the present invention, in which the electrode penetration part 7 and the furnace lid contact surface 8 are surrounded by a common seal chamber 9'.

With such a configuration, there is no need to divide the seal chamber into an electrode penetration part and a furnace cover contact surface, making the operation easier.

In FIGS. 2 to 5, the same reference numerals as those shown in FIG. 1 indicate the same parts.

In addition, in the embodiments of the present invention, the case where the gas fed into the seal chamber is air or nitrogen gas has been explained, but it is also possible to use other inert gases, and the gist of the invention is explained below. Of course, various changes may be made within the scope.

According to the dust collection method for an arc furnace of the present invention, (1) a sealing gas having a pressure equal to or higher than the pressure inside the furnace is supplied to the seal chamber provided at the electrode penetration part or the furnace lid contact surface, and the This prevents the gas inside the furnace from blowing out.
The amount of outside air that enters the furnace through the work openings and tapping ports located low on the furnace wall is significantly reduced, and as a result, the power consumption of the dust collector is greatly reduced, resulting in a significant reduction in dust collection power costs.

α) Since seal gas is constantly leaking from the seal chamber into the furnace and the atmosphere, low temperature seal gas is always supplied to the seal chamber. Therefore, since the small ceiling part of the furnace cover is constantly cooled, the life of the bricks in the small ceiling part is extended.

(To) The graphite electrode is also cooled downward, reducing its consumption.

etc., various excellent effects can be achieved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional arc furnace, FIG. 2 is an explanatory diagram of an embodiment of the dust collection method for an arc furnace of the present invention, and FIG. 3 is a detailed diagram of a part of the seal chamber shown in FIG. FIG. 4 is an explanatory diagram of another embodiment of the dust collection method for an arc furnace according to the present invention, and FIG. 5 is an explanatory diagram of still another embodiment of the dust collection method for an arc furnace according to the present invention. In the figure, 4 is the furnace lid, 4a is the small ceiling, 7 is the electrode penetration part, and 8 is the furnace! Contact surface, 9, 9' seal chamber, 10 electrode penetration gap, 11 inside furnace, 13 electrode penetration gap, 16
indicates a sealed chamber. Patent application person Ishikawajima Harima Heavy Industries Co., Ltd. Patent applicant agent

Claims (1)

[Claims] 1) A seal gas at a pressure equal to or higher than the pressure inside the furnace is supplied into the seal chamber provided around the electrode penetration part of the furnace lid or the contact surface between the electrode penetration part of the furnace lid and the furnace lid. The furnace gas is prevented from being ejected from the inside of the furnace to the atmosphere, and the furnace gas is exhausted from the electrode penetration part of the furnace body and the part where the furnace contact surface is located to collect dust. Dust collection method for arc furnaces.