KR101569592B1 - Apparatus for measuring the steel height in tap-hole of electric furnace - Google Patents

Abstract

An apparatus for measuring the level of a bath surface of an electric arc furnace is introduced.
To this end, the present invention relates to a lance for spraying a purging gas on a slag surface; A radar body provided at an upper end of the lance to emit a microwave; a housing capable of protecting the radar body from falling objects; a microwave irradiated by the molten steel bath surface, the microwave being reflected from the molten steel bath surface, And an antenna having one end connected to the radar body and the other end extended to a nozzle provided at the lower end of the lance so as to be able to detect the ladle body, And the housing is provided with an air supply port through which air can be injected to cool the lance and the antenna by the cold air supplied through the air supply port and to be installed at the lower end of the lance with the pressure of the supplied cold air, Preventing the dust from flowing through the nozzle, and adjusting the height measured by the bath surface level measuring unit So that the distance between the lance and the bath surface is kept constant.

Description

TECHNICAL FIELD [0001] The present invention relates to an apparatus for measuring a level of a bath surface of an electric furnace,

More particularly, the present invention relates to an apparatus for measuring the level of a bath surface of an electric arc furnace, and more particularly, to a system for measuring a bath surface level of an electric arc furnace using a radar body for emitting a microwave to the upper portion of a lancet and an antenna extending from the radar body. Contact type, and then maintains the injection amount of the gas ejected onto the bath surface and the injection pressure at an optimum state.

Generally, an electric furnace is used to heat and dissolve a metal or an alloy by using electricity. When a high current is passed through an electrode of a cover that opens and closes an upper part of the electric furnace, high temperature arc heat is generated, do.

In this electric furnace, slag leakage is a problem during the excavation. The leakage of slag during excavation occurs when the electric furnace is tilted for excavation, by vortex formation during excavation, or when the electric furnace is erected and reversed after excavation . In particular, when the molten steel is introduced through the ladle, a swirling phenomenon occurs from the molten steel bath surface to the ladle opening side, and the center of the molten steel is formed into a funnel shape, so that the slag present in the upper portion of the molten steel is mixed with the molten steel.

In order to solve such a problem, it is known in the prior art as "an apparatus for preventing leakage of electric furnace slag and a method thereof (Patent Laid-open Publication No. 10-2001-0061582) ".

On the other hand, an electric furnace is a furnace that uses heat to heat it. It is widely used for metal refining. This electric furnace has a resistance, an arc and an induction furnace. Generally, in steel making, the principle of generating intense light and high temperature heat The used acro is widely used.

Generally, the electric arc furnace is operated after the scrap iron and the limestone are charged, and after passing through the dissolving process of injecting oxygen through the start of burning and burner operation, the temperature is finally measured after the oxidation process of measuring the components and measuring the components.

The slag generated as a result of the melting process after scrap iron charging is drained to the ladle through the EBT hole during the final ladle process, and the slag thus discharged is a decisive factor in deteriorating the quality of steel products.

Currently, a system is being operated to prevent slag leakage by spraying inert gas against slag which adversely affects the quality of steel products.

In such a system, the flow rate and pressure of the injected gas due to the tilting of the electric furnace have a crucial influence on the amount of slag flowing out during the running, and it is operated to measure the distance between the electric furnace bath surface and the gas injecting apparatus and to reflect the data It is very important to improve the efficiency of the facility.

In view of this, an in-furnace level meter for measuring levels of molten steel and raw materials in a furnace or the like using a microwave, and an antenna for use in the furnace level meter (Korean Patent Publication No. 1994-0011332) 1 is a configuration diagram of such a conventional leveling device.

However, in the case of the above-mentioned invention, (a) a transmission antenna of a microwave to be launched towards the bath surface and a reception antenna to receive a reflected microwave are provided separately, which complicates the structure of the equipment itself, (B) the inner diameters 110a and 110b of the enlarged diameter portion each function as an antenna horn. Since the material of the antenna horn is made of ordinary steel, it can be easily attached and easily removed at the time of operation. (C) Coolant flows through the cooling water path (95a) on the outside and the cooling water path (95b) on the inside, thereby protecting the lance which operates in the high temperature inside the cooling water. There is a limitation in that a safety accident may occur due to an explosion when the cooling water flows into the bath surface.

It should be understood that the foregoing description of the background art is merely for the purpose of promoting an understanding of the background of the present invention and is not to be construed as adhering to the prior art already known to those skilled in the art.

Korean Patent Laid-Open Publication No. 10-2001-0061582 (published July, 2001) Korean Patent Registration No. 1994-0011332 (published on December 20, 1991)

In order to solve the above-mentioned conventional problems, the present invention provides a microwave oven capable of accurately measuring the level of the bath surface on the side of the electric furnace entrance by providing a radar body and an antenna capable of emitting microwaves on the top of the lance, (B) Prevent the safety accident problem caused by the outflow of the conventional cooling water by adopting the air cooling method by air injection instead of the cooling water method, (c) It is an object of the present invention to provide an apparatus for measuring the level of a bath surface of an electric arc furnace in which a material is changed.

An apparatus for measuring the level of a bath surface of an electric arc furnace is introduced.

To this end, the present invention relates to a lance for spraying a purging gas on a slag surface; A radar body provided at an upper end of the lance to emit a microwave; a housing capable of protecting the radar body from falling objects; a microwave irradiated by the molten steel bath surface, the microwave being reflected from the molten steel bath surface, And an antenna having one end connected to the radar body and the other end extended to a nozzle provided at the lower end of the lance so as to be able to detect the ladle body, And the housing is provided with an air supply port through which air can be injected to cool the lance and the antenna by the cold air supplied through the air supply port and to be installed at the lower end of the lance with the pressure of the supplied cold air, Preventing the dust from flowing through the nozzle, and adjusting the height measured by the bath surface level measuring unit So that the distance between the lance and the bath surface is kept constant.

delete

delete

And a horn antenna composed of a gray iron material is installed at the front end of the antenna so that molten steel can be easily removed.

delete

On the other hand, an electric furnace equipped with the bath surface level measuring device of the electric furnace entrance and exit as described above is introduced.

To this end, the present invention provides a post bar comprising: a post bar positioned adjacent to an electric furnace; A swing bar rotatably connected to the post bar so as to rotate in a direction in which the tool of the electric furnace is located; A boom comprising a support frame connected to the swing bar in a horizontal direction and a guide frame bent in a direction perpendicular to an end of the support frame; A lance that injects a purging gas to a slag surface located at a laden port of the electric furnace; And a radar body disposed at an upper end of the lancet, a radar body installed inside the radar body to emit electromagnetic waves toward the bath surface, and an antenna having one end connected to the radar body and the other end extended to a nozzle provided at the lower end of the lancet A tumbling level measuring unit for measuring a tumbling surface height at the side of the lubrication port where molten steel is discharged; Wherein the housing is provided with an air supply port through which the air can be injected to cool the lance and the antenna by the cold air supplied through the air supply port and pressurize the lance with the pressure of the supplied cold air, And the distance between the lance and the bath surface is kept constant by using the height measured by the bath surface level measuring unit.

delete

A horn antenna made of a gray iron is provided at the tip of the antenna, and an air supply port through which air can be injected is formed in the housing.

According to the apparatus for measuring the level of the bath surface of the electric arc furnace of the present invention constructed as described above, the following various effects are realized.

First, the use of radar waves that are less influenced by strong light and dusts of molten steel has the advantage of increasing the reliability of data when measuring the level of the hot water level.

Second, by providing the measured distance value to the slag leakage preventing device, the distance between the bath surface and the lance for spraying the purging gas is maintained, thereby reducing the amount of slag flowing out by controlling the tilting angle at the time of launch.

Third, the use of air other than the cooling water reduces the risk of explosion that may occur due to the leakage of the conventional cooling water, and it also provides various advantages such as reducing the amount of dust flowing through the lance due to air pressure.

1 is a cross-sectional view of a conventional in-furnace level meter;
FIG. 2A is an internal cross-sectional view of a lance of a bath surface level measuring apparatus of an electric arc furnace of the present invention. FIG.
2B is an enlarged view of a radar main body which is one component of the present invention.
3 is an overall view of an electric furnace equipped with an apparatus for measuring the level of a bath surface of an electric arc furnace of the present invention.
4 is an enlarged front view of the bath surface level measuring device of the lap.
Fig. 5 is an enlarged plan view of a bath surface level measuring apparatus of a lubrication port. Fig.
Figs. 6 and 7 are a side view and a plan view of the guide frame; Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a bath surface level measuring apparatus for an electric launch hall of the present invention will be described with reference to the accompanying drawings.

2A is an internal cross-sectional view of a lance of a bath surface level measuring apparatus of an electric arc furnace of the present invention.

As shown in the drawing, the present invention mainly includes a lance 100 and a bath surface level measuring unit 200 installed on the lance 100.

In general, the purging gas uses nitrogen (N ₂ ) or argon (Ar). The purging gas is injected toward the slag located above the inlet 30 at the end of the lance 100.

The bath surface level measuring unit 200 is installed on the lance 100 to measure the bath surface height on the side of the lap 30 through which the molten steel is discharged and emits an electromagnetic wave toward the bath surface through the bath surface level measuring unit 200 do.

Before describing the bath surface level measuring unit 200 in detail, the characteristics of the radar and the microwave will be briefly described as follows.

Radar is an abbreviation of Radio Detecting And Ranging. It emits an electromagnetic wave of microwave (microwave, 10cm ~ 100cm wavelength) to an object and receives the electromagnetic wave reflected from the object to measure the distance, direction, altitude And the like.

This microwave is short in wavelength and has straightness like light and is not reflected by the ionosphere. Therefore, the radio wave emitted from the directional antenna goes straight to the target and then reflects back.

You can find the distance, direction, and altitude of the target by measuring the time of reflected electromagnetic waves. You can find the position, topography, formation, etc. of the object through this information.

In the case of using the radar and the antenna, unlike the laser leveler using light, which is another non-contact type measuring instrument, and the ultrasonic leveler using sound waves, there is an advantage of obtaining data that can measure an accurate distance to an object by using electromagnetic waves.

The present invention is an apparatus for accurately obtaining a bath surface distance from a bottom of a lance to a side of a molten steel lance by providing a radar and an antenna having the above advantages on the lancet. Hereinafter, the bath surface level measuring unit 200 will be described in detail As follows.

As shown in the drawing, the bath surface level measuring unit 200 includes a radar body 210 and a housing 220.

The radar body 210 is connected to an antenna 230 that emits a microwave to be described later on a bath surface, and a waveform amplifier is installed in the radar body 210, and is located at the top of the lance 100.

A specific configuration of the radar body 210 will be described with reference to FIG. 2B.

A main body upper cover 211 is provided at an upper end of the lance 100 and a cable inlet 213 for signal transmission is provided at a lower portion of the lance 100. A ground terminal 212 is provided between the cable inlets 213, And a radar collector 214 of Teflon, which has high heat resistance so as to be capable of emitting / collecting radar waves, is provided at the lower end.

The ground terminal 212 and the cable inlet 213 for signal transmission are peripherals installed in the conventional radar, and a detailed description thereof will be omitted.

Meanwhile, the environment in which the lance 100 is driven may include various dusts in the electric furnace at a high temperature, and dust or drops may flow into the lance 100, which may cause equipment failure. In the case of the required radar body 210, there is a need to protect it from the surroundings.

The housing 220 is also located at the upper end of the lance. The housing 220 has a generally cylindrical shape, and the housing 220 has a generally cylindrical shape. And serves to protect the radar body 210 from falling objects around the electric furnace.

Meanwhile, as shown in FIG. 2A, an antenna is connected to the radar body.

The antenna 230 not only emits microwaves to the molten steel bath surface but also detects the waves reflected from the molten steel bath surface by the microwaves.

One end of the antenna is connected to the radar body 210 and the other end of the antenna is connected to a nozzle 10 disposed at the lower end of the lance so as to accurately measure the level of the molten steel located above the louver 30 ).

Referring to FIG. 2A again, the present invention is characterized in that a horn antenna 231 made of a gray iron material is provided at the tip of the antenna. Before the detailed description, the horn antenna 231 will be described as follows.

A horn antenna is a kind of microwave antenna. It is used to send a wave directly to a space by extending the end of a circular or rectangular waveguide into a trumpet shape.

Gray cast iron is a cast iron in which a large amount of carbon precipitates in the form of graphite when the casting speed is extremely low when the cast iron is injected into the casting mold and its fracture surface is grayed.

On the other hand, SiMn, FeSi, FeMn and the like are additionally added to the components of the molten steel in addition to C, Si and Al. The molten steel is also formed in the molten steel. However, It is possible to facilitate the dropping of molten steel now and which can be attached to the horn antenna when the gas is purged by the molten steel located above the louver 30.

That is, the components of the molten steel and the present horn are different from those of the horn antenna, so that the molten steel and the present horn can be easily separated from each other due to the heterogeneity of the components when they are separated from the horn antenna.

The present invention is characterized in that the material of the horn antenna is made of gray cast iron so that the above properties can be utilized.

Referring to FIG. 2A again, the present invention is characterized in that an air supply port 300 is formed at one side of a housing 220 that protects the radar body 210, into which air can be injected.

Conventionally, a lance has a double structure composed of an inner pipe and an outer pipe. The inner pipe is a pipe through which a purging gas flows. A gas cable is connected to the inner pipe to form a gas flow path through which the purging gas moves. So that the peripheral equipment is protected from the high temperature in the electric furnace.

In addition, when the conventional antenna described in the background art is installed in the above-described structure, if the cooling water flowing in the wave guide pipe flows into the bath surface due to the breakage due to the attachment, there is a problem of causing an explosion.

The present inventor has recognized that such a problem is caused by providing an air supply port 300 capable of injecting cold air into one side of the housing 220 and a compressor capable of supplying cold air to the air supply port 300. [ (Not shown), and protects surrounding equipment including the lance 100 by cold air rather than cooling water.

The air supply port 300 is installed through the housing 220 at a predetermined depth from one side of the housing 220. Air is injected through the passage to protect the lance while flowing inside the lance.

Air having a predetermined pressure is injected through the air supply port 300 to prevent the inflow of dust that enters the nozzle 10 installed at the lower end of the lance into the air pressure so as to protect the radar body 210 .

Fig. 3 is an overall configuration view of an electric furnace equipped with an apparatus for measuring the level of a bath surface of an electric arc furnace of the present invention. Fig. 4 is an enlarged front view of the apparatus for measuring the bath surface level of the furnace, Fig.

As shown in the figure, the present invention mainly includes a post bar 400, a swing bar 500, a boom 600, a lance 100, and a bath surface level measuring unit 200.

Specifically, the post bar 400 is a frame for supporting the swing bar 500, the boom 600 and the lance 100, and supports the lower end of the swing bar 500 so as to allow the swing bar 500 to rotate And is located adjacent to the electric furnace 700 having the can opener 20.

The lancing tool 100 according to the present invention is an entrance and exit of the lance 100 according to the present invention. The lance 100 is positioned opposite to the upper side of the lance opening 30 through which the molten steel is discharged. do.

The lower end of the post bar 400 is fixed to the upper part of the electric furnace 700 or fixed to the upper part of the electric furnace 700 by a separate pedestal and the swing bar 500 is rotatably connected to the upper end thereof.

A swing bar 500 may be provided between the post bar 400 and the swing bar 500 to allow the swing bar 500 to rotate So that the boom 600 equipped with the lance 100 is rotated in the lateral direction in which the dog tool 20 of the electric furnace 700 is located. To this end, a swing bar 500 is provided at one side thereof with a rotation motor 40 for providing a swinging force to the swing bar 500.

For example, a rotary motor 40 having a pinion gear may be mounted on one side of the swing bar 500 and a rake-shaped gear engaged with the pinion gear may be formed on the outer circumferential surface of the swing bar 500, The swing bar 500 may be rotated on the upper side of the post bar 400 during operation

The structure in which the pinion gear of the rotary motor 40 is engaged with the rake-tooth is merely an example of allowing the swing bar 500 to be rotated at the upper end of the post bar 400, Between the bars 400, various types of rotating structures for rotating the swing bars 500 may be applied.

The boom 600 is a frame connecting the swing bar 500 and the lance 100 and is connected to the swing bar 500 such that the swing bar 500 can rotate at a predetermined angle with the swing bar 500 as a rotation axis. The boom 600 is composed of a support frame 610 and a guide frame 620 which are connected in a "?"

In addition, the flexible tube T shown in FIG. 4 is a tube into which inert gas is introduced into the lance 100, and the purging gas moves through the channel.

6 and 7 are a side view and a plan view of the guide frame.

As shown, the support frame 610 is connected to the swing bar 500 in a horizontal direction, the guide frame 620 is connected to the end of the support frame 610 so as to be bent in the vertical direction, And the first and second limit switches 322a and 322b for sensing the first and second limit strikers 451a and 451b are provided at the upper and lower ends of the first and second limit strikers 451a and 451b.

Particularly, a guide rail 623 is extended from the guide frame 620 to slide the movement cart 450 of the lance 100 in the longitudinal direction thereof. A driving sprocket 321 to which a chain (not shown) is connected is provided. An elevating motor 311 drivingly connected to the driving sprocket 321 is mounted on the supporting frame 610.

Accordingly, when the drive sprocket 321 is rotated by the operation of the elevating motor 311, the chain (not shown) is lifted by the rotation of the drive sprocket 321 and the moving cart 450 is moved up and down, The lance 100 can be moved into and out of the open tool 20 of the electric furnace 700 while being moved in the vertical direction by the movement of the moving cart 450. [

On the other hand, when the chain is lifted and lowered by the operation of the elevating motor 311, the cart rollers 451 of the moving cart 450 are moved up and down along the guide rails 623 of the guide frame 620, When the first or second limit strikers 451a and 451b are detected by the first or second limit switches 322a and 322b when the first and second limit strikers 450 and 450 are positioned at the upper and lower ends of the guide frame 620, The distance of movement of the magnet 450 can be limited.

On the other hand, in the bath surface level measuring apparatus for an electric furnace riser including the post bar 400, the swing bar 500, the boom 600, the lance 100 and the bath surface level measuring unit 200, The unit 200 includes a housing 220 located at an upper end of the lance 100 and a radar body 210 installed therein. One end of the housing 220 is connected to the radar body 210, And a horn antenna 231 made of a gray iron is provided at the tip of the antenna 230. The horn antenna 231 is connected to an air supply port (300) is formed. The detailed structure and function of the substrate 300 have already been described.

Hereinafter, the operation of the present invention will be described.

First, the elevating motor 311 of the opening / closing unit 800 is operated to open the can opener 601 in the process of opening and closing the electric furnace 700. The swing bar 500 is rotated by a predetermined angle such that the swing bar 500 is positioned at a position where the guide frame 620 of the boom 600 is opposed to the tool 20 by operating the rotary motor 40, When the guide frame 620 of the boom 600 is positioned at a position opposed to the dog tool 601, the elevating motor 311 is operated to move the moving cart 450 in the downward direction, Is located on the upper side of the slag surface. When the end of the lance 100 is positioned on the upper side of the slag surface, the purging gas is sprayed to the slag surface through the nozzle 10 of the lance to remove the slag on the surface of the molten steel, thereby preventing the slag from flowing out to the slit.

After the end of the lance 100 is positioned above the slag surface through the lifting motor 311 and the moving cart 450 as described above, the purging gas is supplied to the slag surface through the nozzle 10 of the lance 100 The distance between the bottom of the lance and the bath surface on the side of the lubrication port is measured through the bath surface level measuring unit 200 which is installed on the lance 100 and blows electromagnetic waves toward the bath surface before and during the spraying.

That is, the antenna 230, which is connected to one end of the radar body 210 located at the upper end of the lance 100 and the other end of which is connected to the nozzle 10 provided at the lower end of the lance, And the distance from the bottom to the bath surface on the side of the lubrication port is measured.

The measured value is used to maintain the distance between the utilization bath surface and the lance 100 injecting the purging gas at a constant value, and by controlling the tilting angle of the electric furnace at the time of using the distance value, the amount of slag discharged can be reduced The effect is realized.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. It will also be appreciated that many modifications and variations will be apparent to those skilled in the art without departing from the scope of the present invention.

10: Nozzle 40: Rotary motor
100: lance 200: bath surface level measuring unit
210: radar body 211: main body upper cover
212: ground terminal 213: cable entry
214: Radar collector 220: Housing
230: antenna 231: horn antenna
300: air supply port 311: elevating motor
321: drive sprocket 322a, 322b: first and second limit switches
400: Post bar 450: Guide rail
451a and 451b: first and second limit strikers
500: Swing bar 600: Boom
610: Support frame 620: Guide frame
623: Go cart 700: Electric furnace
800: opening / closing unit

Claims (8)

A lance for spraying a purging gas on the slag surface;
A radar body provided at an upper end of the lance to emit a microwave; a housing capable of protecting the radar body from falling objects; a microwave irradiated by the molten steel bath surface, the microwave being reflected from the molten steel bath surface, And an antenna having one end connected to the radar body and the other end extended to a nozzle provided at the lower end of the lance so as to be able to detect the ladle body, Including,
The housing is provided with an air supply port through which air can be injected. The lance and the antenna are cooled by the cold air supplied through the air supply port, and the pressure of the supplied cold air is supplied through a nozzle Preventing dust from entering,
And the distance between the lance and the bath surface is kept constant by using the height measured by the bath surface level measuring unit.
delete delete The method according to claim 1,
And a horn antenna made of a gray cast iron material is installed at the front end of the antenna so that molten steel can be easily removed therefrom.
delete A post bar positioned adjacent to the electric furnace;
A swing bar rotatably connected to the post bar so as to rotate in a direction in which the tool of the electric furnace is located;
A boom comprising a support frame connected to the swing bar in a horizontal direction and a guide frame bent in a direction perpendicular to an end of the support frame;
A lance that injects a purging gas to a slag surface located at a laden port of the electric furnace; And
A radar body disposed at an upper end of the lance; a radar body provided inside the radar body to emit electromagnetic waves toward the bath surface; and an antenna having one end connected to the radar body and the other end extended to a nozzle provided at the lower end of the lancet, A bath surface level measuring unit for measuring a bath surface height at the side of the inlet and outlet where molten steel is discharged; Lt; / RTI >
The housing is provided with an air supply port through which air can be injected. The lance and the antenna are cooled by the cold air supplied through the air supply port, and the pressure of the supplied cold air is supplied through a nozzle Preventing dust from entering,
And the distance between the lance and the bath surface is kept constant by using the height measured by the bath surface level measuring unit.
delete The method of claim 6,
A horn antenna made of gray iron is provided at the tip of the antenna,
Wherein the housing is provided with an air supply port through which air can be injected.

Images