JP3678379B2 - Electric arc furnace electrode support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrode support device for an electric arc furnace, which is applied to a steelmaking arc furnace or a refining furnace having a three-phase alternating current method or a direct current method, and by devising a cooling method for the electrode support beam or electrode holder. It relates to improvements to reduce weight and improve maintainability.
[0002]
[Prior art]
Generally, in an electric arc furnace, three graphite electrodes are inserted into the furnace in the case of the three-phase AC method, and one graphite electrode is inserted into the furnace in the case of the DC method. An arc is generated between a material such as scrap iron and the electrode to melt the material and heat the molten steel.
When the melting process and the refining process are performed separately, a steelmaking arc furnace and a refining arc furnace are provided for each process. The former is a three-phase AC arc furnace or a DC arc furnace, and the latter is a three-phase arc furnace. A phase AC arc furnace is applied.
[0003]
And in an electric arc furnace, it is necessary to control the amount of graphite electrodes inserted into the furnace, so an electrode support device consisting of an electrode holder for holding the electrode and an electrode support beam integrally formed with the electrode holder is indispensable. However, taking an electrode support device applied to a three-phase AC arc furnace as an example, it has a configuration as shown in FIG. 7 (plan view) and FIG. 8 (side view: AA arrow in FIG. 7). ing.
[0004]
In each figure, 1a to 1c are electrodes inserted into the furnace, 2a to 2c are electrode holders that hold the electrodes 1a to 1c, 3a to 3c are electrode support beams, 4a to 4c are terminals, and 5a to 5c (5c is (Omitted) indicates a flexible cable connecting the terminals 4a to 4c and a furnace transformer (not shown).
Here, the electrode support beams 3a to 3c are made of a conductor for supplying a large current (copper or aluminum alloy), and the electrode support beams 3a to 3c and the electrode holder 2a to the terminal 4a to 4c when the electric arc furnace is operated. Large power to electrodes 1a-1c via 2c Flow Supplied.
Each electrode support beam 3a-3c is mounted on a lifting mast 7a-7c (7c not shown) via insulating plates 6a-6c (6c not shown), and is lifted during operation. The masts 7a to 7c are driven and controlled in the vertical direction, and stable arcs are generated by adjusting the insertion amounts of the electrodes 1a to 1c into the furnace.
[0005]
7 and 8 are three-phase AC arc furnaces, so there are three electrodes 1a to 1c, and inevitably three electrode support devices including electrode holders 2a to 2c and electrode support beams 3a to 3c. However, in the case of a DC arc furnace, one unit is sufficient.
Furthermore, in the above example, the electrode support beams 3a to 3c themselves are used as a conductor for supplying a large current, but a conductive rod such as a copper tube is separately provided on the upper side of the electrode support beam to provide a large current supply path. Sometimes.
[0006]
[Problems to be solved by the invention]
By the way, the electrode support device (electrode holder and electrode support beam) generates heat due to its internal resistance when a large current is applied during operation, and fire or gas blown out of the furnace, or radiation from a red hot electrode, Since it is heated by heat conduction, it needs to be always cooled.
Therefore, in the conventional electrode support apparatus, as shown in FIG. 8, the electrode support beams 3a to 3c configured as hollow cylinders have a watertight structure, and partition plates 8a to 8c (8c not shown) are provided therein. The cooling water supply ports 9a to 9c (9c not shown) and drainage ports 10a to 10c (10c not shown) are provided above and below the rear end portion. A cooling system is adopted in which the water supplied from the supply ports 9a to 9c bypasses the front end sides of the partition plates 8a to 8c and returns to the drain ports 10a to 10c to be drained. That is, heat is absorbed from the inner wall surfaces of the electrode support beams 3a to 3c in the process of water flowing through the upper and lower spaces of the partition plates 8a to 8c, so that the electrode support beams 3a to 3c are maintained at a certain temperature or lower. ing.
Although not shown, the electrode holders 2a to 2c are also formed with meandering water passages with a partition plate inside thereof, and the water is supplied to the flexible tubes 11a to 11c (11c not shown). It is made to cool by circulating inside.
[0007]
As described above, the conventional electrode support device has a cooling function by a water flow method using water as a cooling medium, but the following problems have been pointed out.
(1) In order to allow water to flow while the inside is filled with water, the weight of the water reaches several tens of percent of the lifting and lowering weight, and it is necessary to have something that can supply a large driving force to the electrode lifting and lowering drive device Incurs a cost increase of the entire system.
In particular, when the electrode support beam is made of a highly conductive material and also serves as a large current supply conductor, it is necessary to increase the cross-sectional dimension of the beam itself. The load becomes very large.
(2) If the cross-sectional area of the water flow path in the electrode support beam increases, the water flow rate will slow down, causing problems such as sludge accumulation and reduced cooling capacity, and maintenance work must be performed frequently.
(3) Because cooling water is allowed to pass through under pressure, even if the electrode holder or electrode support beam is a hole due to minor damage due to a spark accident, water is ejected vigorously. Because there are many things that cannot be dealt with, the operation is forced to be interrupted.
(4) In the process of flowing water in a full state, only the layer part in contact with the inner surface of the beam actually contributes to the cooling of the electrode support beam. Its cooling efficiency is low.
[0008]
On the other hand, recently, an ultra-small cooler capable of injecting cold air at a very low temperature just by supplying high-pressure air has been developed.
A schematic diagram of the cooler is shown in FIG.
In the figure, 21 is a generator section, 22 is a cold air discharge nozzle, 23 is a heat exchange tube section, 24 is a hot air discharge port, and 25 is a control valve.
[0009]
In this cooler 20, when high-pressure air is supplied to the air supply port 21a of the generator unit 21, the air guiding unit 21b built in the generator unit 21 converts the air into an ultrahigh-speed vortex 26 to convert the air into a heat exchange cylinder. Guide to the inner peripheral surface of the part 23.
A large centrifugal force acts on the air of the ultra-high speed vortex 26 and advances backward while spirally rotating along the inner peripheral surface of the heat exchange cylinder portion 23.
On the other hand, a cavity is formed inside the ultra-high speed vortex 26, but the air drawn into the cavity becomes a driven vortex 27 rotated in the same direction as the vortex 26, and the vortex 25 It proceeds in the direction opposite to the direction of travel.
[0010]
In that case, in terms of energy, the outer ultra-high speed vortex 26 inside the heat exchanging cylinder portion 23 has an extremely high peripheral speed, so a substantially cylindrical stagnation surface is formed between the inner driven vortex 27 and the inner driven vortex 27. However, the pressure of the ultrahigh-speed vortex 26 gradually decreases as it progresses backward, while the inner driven vortex 27 exerts a braking action on the outer ultrahigh-speed vortex 26 near the stagnation surface. Therefore, the amount of heat of the driven vortex 27 moves to the super high speed vortex 26, the driven vortex 27 is cooled and advances to the front generator section 21 side, and the super high speed vortex 26 advances to the rear hot air outlet 24 side.
The air guide part 21b of the generator part 21 is formed with a through hole in its axial direction, and the cooled driven vortex 27 passes through the through hole and is injected from the cold air discharge nozzle 22.
Further, the super high speed vortex 26 takes heat from the driven vortex 27 and becomes hot air reduced in speed, and is discharged from the hot air outlet 24.
The control valve 25 plays a role of controlling the amount of hot air discharged from the hot air discharge port 24, and has a function of controlling the heat exchange rate by adjusting it (cooling air temperature adjusting function).
According to an example of the actual machine of the cooler 20, the generator has a total length of 165mm and a diameter of the generator section 21 of about 35mm. Air at normal temperature (21 ° C) is 7kg / cm from the air supply port 21a. ² When supplied with G pressure, 22 can inject cold air of −44.5 ° C. from the cold air discharge nozzle (however, atmospheric pressure 0 kg / cm ² G).
[0011]
Therefore, the present invention is based on the fact that the total weight of the device is increased because the conventional electrode support device passes water while cooling the electrode support beam while filling the electrode support beam, and the ultra-small cooling as described above. The present invention was created with the object of providing an electrode support device that solves the above-mentioned various problems in consideration of the fact that the device is being developed.
[0012]
[Means for Solving the Problems]
In a first aspect of the present invention, there is provided an electrode support device for an electric arc furnace in which an electrode support beam having a cavity structure is cooled from the inside. The inside of the electrode support beam is configured to be able to store water, and a drainage pipe is attached to the lower side wall portion of the electrode support beam to supply high pressure water to the high pressure water supply pipe. An electric arc characterized in that water is injected from the injection nozzle onto the inner wall surface of the electrode support beam to cool the wall portion, and the water stored in the lower portion of the electrode support beam is discharged from the drainage pipe. The present invention relates to a furnace electrode support device.
[0013]
In this invention, a wall part can be cooled by the water sprayed in the spray form without filling the inside of an electrode support beam, and the water stored slightly in the lower part, and the total weight of an electrode support apparatus can be reduced significantly.
In addition, since no great pressure is applied to the cooling water, a perfect watertight structure is not required for the electrode support beam, and even if a slight damage occurs to the electrode support beam, a large amount of water does not spout. .
Even if the electrode support beam is filled with water and passed therethrough, only water near the wall surface contributes to cooling, but in this embodiment, high cooling efficiency can be realized with a small flow rate.
[0014]
According to a second aspect of the present invention, there is provided an electrode support device for an electric arc furnace using a system in which an electrode support beam having a cavity structure is cooled from the inside. A large number of small coolers that separate the cold air and hot air by supplying high-pressure air, with the cold air injection port facing the inner wall surface of the electrode support beam. Attach along the axial direction of the beam, connect the high pressure air supply port to the high pressure air supply tube, connect the hot air discharge port to the hot air exhaust tube, and connect the high pressure air supply tube with high pressure Air is supplied to cool the wall of the electrode support beam by ejecting cold air from the cold air outlet of each of the small coolers, and hot air discharged from the hot air outlet is passed through the hot air exhaust pipe. Exhausted outside According to the electrode supporting device for an electric arc furnace, wherein Rukoto.
[0015]
The present invention enables cooling of the electrode support beam by forced air cooling.
As the small cooler, the one corresponding to the cooler shown in Fig. 9 can be applied, and since it is small and lightweight, it is compared with the conventional method of filling water with water even when the weight of the pipes is combined. Thus, a much lighter electrode support device can be constructed.
Moreover, since it is cooled by ultra-low temperature air, it is efficient, and all the various problems caused by using water as a cooling medium in the prior art because water is not particularly used are all eliminated.
[0016]
According to a third aspect of the present invention, there is provided an electrode support device for an electric arc furnace that cools an electrode support beam having a cavity structure from the inside, wherein a plurality of holes are formed in at least a front end wall portion and all side wall portions, and a rear end A box-shaped housing provided with a cooling air supply port on the wall was loaded inside the electrode support beam with a gap interposed therebetween, and the cooling air supply port of the box-shaped housing was generated by an external cooler. The present invention relates to an electrode support apparatus for an electric arc furnace, characterized by supplying high-pressure cooling air to cool a wall portion of the electrode support beam.
[0017]
According to the present invention, unlike the second invention, a large number of small coolers are not mounted inside the electrode support beam, but cooling air is collectively supplied from the external large-capacity cooler to the box-shaped housing. The cooling air can be evenly sprayed onto the wall surface of the electrode support beam from a large number of holes.
The box-shaped casing can be easily configured with a relatively thin plate, and since no mechanical elements other than the box-shaped casing are mounted, the total weight of the electrode support device can be extremely reduced.
Since this invention is also a forced air cooling system using cooling air as in the second invention, there are no problems caused by the use of water.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
The structure of the electrode support device of this embodiment is shown in FIG. 1 (side view) and FIG. 2 (cross-sectional view). However, although FIG. 1 is a side view, the electrode support beam 31 is a cross-sectional view, and FIG. 2 corresponds to a cross-sectional view taken along the arrow BB in FIG.
In the figure, 1 is a graphite electrode and 2 is an electrode holder, which have substantially the same configuration as that shown in FIGS.
[0019]
The feature of this embodiment is as follows.
First, a pipe 32 for passing cooling water along the axial direction of the electrode support beam 31 is piped inside the electrode support beam 31, and the pipe 32 has an opposite portion between the upper side wall and both side walls. A large number of injection nozzles 33 are arranged in alignment along the axial direction.
The tip of the tube 32 reaches the front wall surface of the electrode support beam 31 but is sealed at that portion, while the rear end side of the tube 32 is bent downward, and the electrode support beam 31 It is connected to a cooling water supply port 34 provided on the lower side wall. Further, a drain port 35 is provided on the rear end side of the lower side wall of the electrode support beam 31.
[0020]
In the electrode support beam 31 according to this embodiment, high-pressure water is supplied from the outside to the port 34 during operation of the electric arc furnace.
The supplied water flows into the pipe 32 and enters a high pressure state, but the water in the pipe 32 is ejected from each injection nozzle 33 with a certain spread, and as shown in FIG. It collides with the inner surface of both side walls, wets each surface sufficiently and flows down.
Then, a certain amount of the water that has flowed is collected on the lower side wall of the electrode support beam 31, but is always discharged to the outside through the rear drain port 35.
[0021]
By the way, the water ejected from each ejection nozzle 33 constantly removes the heat accumulated in each wall portion because the upper wall of the electrode support beam 31 and the inner surfaces of both side walls are always wetted and flow down.
Further, the water that has flowed downward and has always accumulated a certain amount is removed from the lower wall of the electrode support beam 31 and discharged from the drain port 35.
Therefore, even if the electrode support beam 31 is heated by resistance heat due to energization of a large current or a flame or gas blown from an electric arc furnace, the amount of heat is always taken away and released to the outside, so the electrode support beam 31 is reduced. It can be cooled efficiently with the amount of water and kept below a certain temperature.
In consideration of the fact that the electrode support beam 31 is heated at the front part closer to the electric arc furnace and the temperature thereof becomes higher, and that the temperature rise is usually not seen only by resistance heat on the rear side, It is also possible to adopt a configuration in which the arrangement pitch of the injection nozzles 33 is reduced and the pitch is increased in the rear, or the injection nozzles 33 are intensively provided only in the front portion.
[0022]
Here, when compared with the cooling method of the electrode support beam 3b according to FIG. 8 shown in the prior art, in this method, the electrode support beam 3b must be constantly filled with water for cooling without passing water. However, according to this embodiment, only the water sprayed in the form of spray and the water that accumulates a little on the lower side are contained in the electrode support beam 31, Even if the weight is added, the total weight is much smaller than that of the conventional electrode support beam 3b.
Further, in this embodiment, since no large water pressure is applied to the inside of the electrode support beam 31, it is not necessary to make the structure a perfect watertight structure, and even if a hole due to minor damage occurs due to a spark accident or the like, However, the water does not erupt vigorously from the hole, and since it can be dealt with by emergency measures, the electric arc furnace will not be shut down.
Furthermore, since the water accumulated below the electrode support beam 31 flows at a relatively high speed and is discharged from the drain port 35, accumulation of sludge and the like can be prevented.
As for the cooling of the electrode holder 2, the conventional water flow method is adopted, but since the amount of water required for cooling is small, the total weight of the entire electrode support device is not significantly affected.
[0023]
<< Embodiment 2 >>
The structure of the electrode support device of this embodiment is shown in FIG. 3 (side view) and FIG. 4 (cross-sectional view). However, although FIG. 3 is a side view, the electrode support beam 41 is a cross-sectional view, and FIG. 4 corresponds to a cross-sectional view taken along the CC line in FIG.
Also in this embodiment, except for the structure of the electrode support beam 41, it has substantially the same configuration as that shown in FIGS.
[0024]
The feature of this embodiment is as follows.
First, a high-pressure air supply tube 42 and hot air discharge tubes 43a and 43b (arranged above and below the tube 42) are provided inside the electrode support beam 41 in a manner along the axial direction of the beam.
Here, the tip of the high-pressure air supply tube 42 reaches the front wall surface of the electrode support beam 41, but is sealed at that portion, while the rear end side of the tube 42 is bent downward. It is connected to an air supply port 44 provided on the lower side wall of the electrode support beam 41. The hot air discharge tubes 43a and 43b are sealed at the front end portions of the front wall surfaces of the electrode support beams 41, and the open ends at the rear ends penetrate the end plates 45 at the rear portions of the electrode support beams 41. And protrudes to the outside.
The end plate 45 does not have the electrode support beam 41 in a sealed structure, and an open port 46 is formed between the end plate 45 and the lower side wall of the electrode support beam 41.
[0025]
In this embodiment, a large number of the above-described microminiature coolers 20 are applied to cool the electrode support beam 41. However, in the following description, the reference numerals with () indicate the cooler shown in FIG. 9 and its respective elements, and the figure is referred to.
Specifically, as shown in FIG. 4, the cooler 20 a, 20 b, 20 c, 20 d of the cool air discharge nozzle (22) is directed to the upper and lower and both side walls of the electrode support beam 41, and the generator section ( An air supply port (21a) 21) is screwed into the high-pressure air supply pipe 42 with a sealing function.
However, as shown in FIGS. 3 and 4, a set of coolers 20a and 20b used for the upper and lower wall surfaces of the electrode support beam 41 and a set of coolers 20c and 20d used for the left and right wall surfaces are In each group unit, they are arranged at the same position in the axial direction of the tube 42 and at different positions between the groups.
[0026]
Each of the hot air discharge ports (24) of the coolers 20a and 20d is connected to a lower hot air discharge pipe 43b via connection pipes 47a and 47d, and the hot air discharge ports (24 of the coolers 20b and 20c ) Is connected to the upper hot air discharge pipe 43a through connection pipes 47b and 47c.
Furthermore, for each of the coolers 20a and 20b used for the upper and lower wall surfaces, the distance between the cold air discharge nozzle (22) and the upper and lower wall surfaces becomes too large. It is configured to hit the upper and lower wall surfaces.
[0027]
In the electrode support beam 41 according to this embodiment, high-pressure air is supplied from the air supply port 44 during operation of the electric arc furnace.
The high-pressure air is supplied to the air supply port (21a) of the generator section (21) of each cooler (20) through the pipe 42, but the cold air from the cool air discharge nozzle (22) of each cooler (20) is cooled. , And hot air by heat exchange is discharged from the hot air discharge port (24).
The cool air blown from the cool air discharge nozzle (22) of each cooler 20a, 20b passes through the extension pipes 47a, 47b, and the cool air blown from the coolers 20c, 20d directly passes through the electrode support beam 41, respectively. It collides with the wall surfaces on the top and bottom and both sides and takes heat from each heated wall surface to cool each wall surface efficiently.
In addition, since all the coolers (20) spray cold air, the inside of the electrode support beam 41 is in a low temperature state like a freezer, and not only the region where the cold air is strongly blown but also the electrode support beam 41 The amount of heat is always taken from the entire inner wall surface, and the entire wall is cooled almost uniformly.
In addition, since the internal space of the electrode support beam 41 has a higher pressure than the outside, the cold air that takes heat from each wall surface flows to the rear side and is discharged from the opening 46, and the inside of the electrode support beam 41 is It continues to be filled with cold air blown from the cooler (20) for a while.
[0028]
On the other hand, hot air discharged from the hot air discharge port (24) of each cooler (20) flows into the hot air discharge tubes 43a and 43b, passes through the tubes 43a and 43b, and passes through the tubes 43a and 43b. It exhausts from the rear end.
In that case, since the heat exchange efficiency of each cooler (20) is influenced by the hot air discharge load, it is necessary to ensure a sufficient inner diameter in the tubes 43a and 43b. Is connected to the pipes 43a and 43b by the connecting pipes 47a, 47b, 47c and 47d, but the fluid resistance between them needs to be as small as possible.
[0029]
As described above, in this embodiment, a large number of ultra-small coolers (20) that generate cryogenic and hot air just by supplying high-pressure air are built in the electrode support beam 41, and high-pressure air is supplied through the pipe 42. Supplying to each cooler (20), the generated cold air collides with the inner wall surface of the electrode support beam 41 to cool the whole efficiently, and the generated hot air is exhausted to the outside through separate pipes 43a, 43b. Yes.
Therefore, since it is a forced cooling method using cold air, even if the weight of the built-in cooler (20) and pipes are combined, water is filled as in the electrode support beam shown in FIGS. Compared to the case, the total weight of the electrode support beam 41 is much lighter, and all the problems caused by using water as a cooling medium can be solved.
In particular, the latter effect is epoch-making. In addition, the internal structure of the electrode support beam 41 can be prevented from being corroded and its life can be extended. There is also an advantage that it is not necessary.
In this embodiment as well, considering the distribution state of the heating temperature in the longitudinal direction of the electrode support beam 41, the arrangement pitch of the coolers (20) is reduced in the front, and the pitch is increased in the rear. Further, a configuration in which the cooler (20) is concentrated on only the front portion can also be adopted.
[0030]
Further, according to this embodiment, on the basis of the configuration shown in FIG. 5, the cooling of the electrode holder 2 and the portion 49 between the electrode holder 2 and the electrode support beam 41 and in contact with the graphite electrode 1 is also performed by cold air. It is easy to use forced cooling.
As shown in the figure, a flow path for circulating and releasing air is formed inside the electrode holder 2, and penetrates the upper wall portion of the electrode support beam 41 from the front end portion of the high pressure air supply pipe 42. The induction tube 50 is piped up to the upper side of the electrode holder 2, and the cold air discharge nozzle (22) of the cooler 20e is attached to the cold air supply port 51 formed on the upper surface of the electrode holder 2, and the induction tube 50 is connected to the air supply port (21a) of the cooler 20e. The guide tube 50 is a flexible tube.
Further, a flow path for circulating air is formed inside the contact portion 49 with the graphite electrode 1, and the electrode support beam 41 is connected from the front end portions of the high pressure air supply pipe 42 and the hot air discharge pipe 43b. The guide pipes 52 and 53 led through the front wall surface to the abutting portion 49 side are piped, and on the other hand, at one end of the flow path formed in the abutting portion 49, a cool air discharge nozzle ( 22) is attached, and the guide tube 52 from the tube 42 side is connected to the air supply port (21a), and the guide tube 53 from the tube 43b is connected to the hot air discharge port (24). Here, the description has been made in relation to the lower contact portion 49, but the upper contact portion has the same configuration, and in that case, a tube instead of the tube 43b is used as shown in the figure. High pressure air of 43a is used.
[0031]
Accordingly, when the cooler 20e and the cooler 20f are respectively supplied with high-pressure air from the tube 42 on the electrode support beam 41 side, the cooler 20e and the cooler 20f supply cryogenic cold air to the electrode holder 2 and the air flow path of the contact portion 49 (upper and lower) The cold air blows away heat from the inside of the electrode holder 2 and the contact portion 49 (upper and lower) and flows out from the other open end of the flow path.
As a result, the electrode holder 2 and the contact portion 49 (upper and lower) are strongly cooled, but the same effect is obtained because of the forced cooling method using air as in the case of the electrode support beam 41. .
[0032]
<< Embodiment 3 >>
The basic structure of the electrode support beam according to this embodiment is shown in FIG.
In this embodiment, a forced cooling method using cold air is adopted as in the second embodiment, but the cooler (20) is not built in the electrode support beam, but a large capacity cooler is installed outside. Guide to the inside of the electrode support beam 61.
Specifically, in addition to the electrode support beam 61 main body, the front end wall portion and the upper and lower and left and right wall portions are plates in which a large number of holes 62 are formed substantially equally, and only the rear end wall portion is formed with holes. A box-shaped casing 63 is formed as a non-plate, and the box-shaped casing 63 is loaded into the electrode support beam 61 to form a so-called double structure.
The box-shaped housing 63 is fixed to the inside of the electrode support beam 61 via a spacer 64, and a port 65 for supplying cold air is provided on the rear end wall portion of the tube 66 for supplying cooling air. The high-pressure air cooled from the external cooler is supplied to the port 65 via the.
The rear end portion of the electrode support beam 61 main body is open.
[0033]
According to the structure of the electrode support beam 61 of this embodiment, when the cooled high-pressure air is sent into the box-shaped housing 63, the inside becomes high pressure, and the box-shaped housing 63 has a buffer function. The cooling air is ejected from each hole 62 and collides with the inner wall surface of the electrode support beam 61 main body.
Accordingly, the jetted cooling air strikes the entire inner wall surface of the electrode support beam 61 main body substantially evenly, and efficient cooling becomes possible.
As for the cooling of the electrode holder 2 and the like, it is sufficient to adopt a conventional water cooling method or to use the configuration of FIG. 5 by a method of separately supplying high-pressure air.
[0034]
The box-shaped housing 63 of this embodiment can be manufactured very easily by using a punching board or the like on the wall portion having a large number of holes 62, and the thickness thereof is reduced by increasing the interposing pitch of the spacers 64. Since it is possible, it can be configured extremely light.
Accordingly, it is natural that the total weight can be made much smaller than that of the conventional water-cooled electrode support beam that is filled with water and is comparable or lighter than the method of the second embodiment. Can be achieved.
Naturally, since it is a forced air cooling system, the same effect as the system of Embodiment 2 is obtained, and above all, it is a great advantage that the structure can be simplified.
In this embodiment as well, a method of changing the density of the holes 62 drilled in the box-shaped housing 63 in accordance with the distribution state of the heating temperature in the longitudinal direction of the electrode support beam 41 can be adopted, and the cooling air Can be used more efficiently.
[0035]
【The invention's effect】
The “electrode support device for an electric arc furnace” according to the present invention has the following effects due to the above configuration.
According to the first aspect of the present invention, since the electrode support beam is cooled by the water injected from the injection nozzle of the high-pressure water supply pipe provided therein, the water is filled as in the prior art. Compared with the cooling method, the entire device can be significantly reduced in weight.
Thereby, an inexpensive electrode driving device having a small driving force can be applied, and driving response can be improved.
Also, sludge can be prevented from accumulating inside the electrode support beam, reducing the burden of maintenance work, and even if a hole occurs in the electrode support beam due to a spark accident or the like, water can be ejected vigorously. In addition, since it can be dealt with with simple emergency measures, it is possible to prevent a decrease in operating efficiency of the electric arc furnace due to water leakage.
Further, since a completely watertight structure is not required unlike the conventional electrode support beam, there is an advantage that the design and manufacture becomes easy.
The invention of claim 2 provides an efficient water injection condition in the invention of claim 1.
The invention of claim 3 employs an air cooling system in which a large number of small coolers are built in the electrode support beams, thereby eliminating all problems caused by using water as a cooling medium and greatly increasing the overall apparatus. Thus, the same effects as those of the invention of claim 1 can be obtained.
The invention according to claim 4 adopts an air cooling method for the electrode gripping portion to enable efficient cooling, and realizes the effect by not using water as in the case of claim 3. In particular, the combined use with the invention of claim 3 has an advantage that high-pressure air supplied to the small cooler can be diverted.
The invention of claim 5 relates to a method for efficiently cooling the electrode support beam by installing a cooler outside, and realizes a simple and extremely light structure of the electrode support beam.
Moreover, since it is an air cooling system, it naturally has the same effect as Claim 3.
[Brief description of the drawings]
FIG. 1 is a side view of an electrode support device according to Embodiment 1 (a portion of an electrode support beam is a cross-sectional view).
2 is a cross-sectional view taken along arrow BB in FIG. 1. FIG.
FIG. 3 is a side view of an electrode support device according to a second embodiment (a portion of an electrode support beam is a cross-sectional view).
4 is a cross-sectional view taken along the CC line in FIG. 3;
FIG. 5 is a side view showing a front end portion of an electrode support beam and an electrode gripping portion (a contact portion and the electrode support beam portion are cross-sectional views).
6 is a side view of an electrode support device according to a third embodiment (the electrode support beam portion is a cross-sectional view). FIG.
FIG. 7 is a plan view of an electrode support device applied to a three-phase AC arc furnace.
8 is a side view taken along the CC line in FIG. 7. FIG.
FIG. 9 is a simplified structural diagram for explaining the principle of a micro cooler;
[Explanation of symbols]
1,1a-1c ... graphite electrode, 2,2a-2c ... electrode holder, 3a-3c, 31,41,61 ... electrode support beam, 4a-4c ... terminal, 5a-5c ... flexible cable (5c not shown) ), 6a to 6c ... insulating plate (6c not shown), 7a to 7c ... elevating mast (7c not shown), 8a to 8c ... partition plate (8c not shown), 9a to 9c ... supply Port (9c not shown), 10a to 10c ... Drain port (10c not shown), 20, 20a to 20d, 20e, 20f ... Cooler, 21 ... Generator section, 21a ... Air supply port, 21b ... Air Guide part, 22 ... Cool air discharge nozzle, 23 ... Heat exchange tube part, 24 ... Hot air discharge port, 25 ... Control valve, 26 ... Super high speed vortex, 27 ... Following vortex, 32,42,43a, 43b, 66 ... Pipe 33 ... Injection nozzle, 34,35,44,51,65 ... Port, 45 ... End plate, 46 ... Open port, 47a to 47d ... Connecting pipe, 48a, 48b ... Extension pipe, 49 ... Contact part, 50,52 , 53 ... induction tube, 62 ... hole, 63 ... box-shaped housing, 64 ... spacer.

Claims (5)

In the electrode support device of the electric arc furnace by the method of cooling the electrode support beam of the cavity structure from the inside, a high pressure water supply pipe having a large number of injection nozzles formed on the outer peripheral surface is piped inside the electrode support beam, The lower part inside the electrode support beam is configured to be able to store water, and a drainage pipe is attached to the lower side wall part, and high pressure water is supplied to the high pressure water supply pipe to supply the electrode from the injection nozzle. An electrode support device for an electric arc furnace, wherein water is injected to an inner wall surface of a support beam to cool the wall portion, and water stored in a lower portion of the electrode support beam is discharged from the drain pipe. The electrode support device for an electric arc furnace according to claim 1, wherein the injection nozzles formed in the high-pressure water supply pipe are aligned to face at least the upper wall surface and both wall surfaces of the electrode support beam. In an electrode support device for an electric arc furnace that cools a hollow electrode support beam from the inside, at least a part of the rear end of the electrode support beam is open inside a high-pressure air supply pipe and hot air exhaust A large number of small coolers that separate and generate cold air and hot air by supplying high-pressure air are provided along the axial direction of the electrode support beam with the cold air injection port facing the inner wall surface of the electrode support beam. And connecting the high-pressure air supply port to the high-pressure air supply tube, connecting the hot air discharge port to the hot-air exhaust tube, and supplying high-pressure air to the high-pressure air supply tube Cooling the wall of the electrode support beam by discharging cold air from the cold air injection port of each of the small coolers, and discharging the hot air discharged from the hot air discharge port to the outside through the hot air exhaust pipe. Characteristic Electric arc furnace electrode support device. A cold air injection port of a small cooler that separates and generates cold air and hot air by supplying high-pressure air to one end of the air passage is formed inside the electrode gripping part connected to the electrode support beam. The electrode support device for an electric arc furnace according to claim 3, wherein the electrode gripping part is cooled by connecting, supplying high-pressure air to the high-pressure air supply port, and discharging cold air from the cold-air injection port. In an electrode support device for an electric arc furnace that cools a hollow electrode support beam from the inside, a large number of holes are drilled in at least the front end wall and all the side walls, and cooling air is supplied to the rear end wall. A box-shaped housing with an opening is loaded inside the electrode support beam with a gap interposed therebetween, and high-pressure cooling air generated by an external cooler is supplied to the cooling air supply port of the box-shaped housing An electrode support device for an electric arc furnace, wherein the wall portion of the electrode support beam is cooled.

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