JP3033036B2 - Oxygen and powder blowing equipment for electric furnaces - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric furnace used for melting metal materials such as scraps, refining molten metal, and the like. The present invention relates to a device for blowing oxygen and powder in a furnace.

[0002]

2. Description of the Related Art An electric furnace used for melting a metal material, refining a molten metal, etc., is attached to an electrode disposed above a metal material charged in the furnace and to a furnace wall such as a furnace bottom and a side wall. A DC electric furnace for melting a metal material and refining a molten metal, and a current between the three electrodes disposed above the metal material charged in the furnace. An AC electric furnace for melting a metal material and refining a molten metal is known.

[0003] This type of electric furnace is generally operated to blow oxygen and powder into the molten metal in the furnace using a consumable pipe in order to promote melting of the metal material and refining the molten metal. It has been done. Conventionally, the oxygen and powder were blown into the furnace while an operator held a consumable pipe while blowing the oxygen and powder. However, in recent years, a blowing method using a consumable pipe has been proposed. The non-consumable water-cooled lance system disclosed in Japanese Patent No. 219116 in which the upper blowing lance of the converter is applied to the electric furnace eliminates the need for a worker to connect a new pipe due to consumption of the pipe in front of the electric furnace. It is adopted as a method to release workers from work under heavy or high temperature environment.

FIG. 6A is a plan view of an oxygen lance and a powder lance of an oxygen and powder blowing apparatus inserted into a furnace of a conventional electric furnace, and FIG. 6B. Is
FIG. 4 is a partially enlarged view of the tip of each lance when the lance for oxygen and the lance for powder are inserted into the furnace, and the oxygen jet stream ejected from the tip nozzle of the lance for oxygen and the powder ejected from the tip of the lance for powder. FIG. FIG. 6C shows a side view thereof.

The powder lance 1 is provided below the oxygen lance 2, and the tip of the powder lance 1 is displaced rearward from the tip nozzle 3 of the oxygen lance 2 by a dimension L (about 300 to 500 mm). Fixedly attached to the lance holding hardware 8. Tip nozzle 3 provided at the tip of oxygen lance 2
Is directed downward by an angle (θ ₁ ) so that the oxygen jet 4 is directed toward the bath surface during operation. For this reason, the powder 5 ejected from the tip of the powder lance 1 collides with the central flow of the oxygen jet 4 ejected from the tip nozzle 3 of the oxygen lance 2, and can be efficiently added to the molten metal. It has a configuration.

[0006]

In the conventional oxygen or powder blowing apparatus, the positional relationship between the powder lance 1 and the tip nozzle 3 of the oxygen lance 2 is fixed. Since the powder 5 ejected from the tip cannot collide with an arbitrary position on the plane of the oxygen jet 4 and the collision distance (L ₂ ) cannot be adjusted arbitrarily, powder carburization into the molten metal is performed. Efficiency could not be adjusted, and there was a limit to maintaining an operation mode that could obtain an appropriate slag forming height according to the operation conditions.

For this reason, 1) the operation involving the extension of the refining time, the deterioration of the power consumption rate and the deterioration of the power consumption rate of the upper electrode is continued, which seriously hinders the improvement of the productivity. The challenge was to expand the degree of freedom to maintain the appropriate operation mode.

[0008] 2) Also, when the scrap is mostly occupied in the furnace, when only the oxygen is blown and the cutting work of the scrap is performed, the tip nozzle 12 of the powder lance 1 is prevented from being clogged by the rebound splash during the cutting. Therefore, it is necessary to flow a large amount of inert gas or the like into the powder lance 1. Since the use of an inert gas or the like greatly contributes to the productivity cost, it is an issue to reduce the use of the inert gas or the like as much as possible.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an electric furnace used for melting a metal material, refining a molten metal, etc., for accelerating the melting of the metal material and refining the molten metal. In a device for injecting oxygen or an oxygen-containing gas and powder through a lance from the upper part in an electric furnace, a powder lance is arranged substantially parallel below the oxygen lance, and the powder lance is connected to the oxygen lance. And the powder lance outlet is attached to the oxygen lance outlet so as to be able to move forward and backward with respect to the oxygen lance outlet.

[0010]

According to the present invention, 1) it is possible to cause the powder ejected from the tip of the powder lance to collide with an arbitrary position on the plane of the oxygen jet, and to adjust the amount of powder entrained in the oxygen jet; In addition, it is possible to arbitrarily adjust the collision distance (L ₂ ) to change the collision velocity (V) of the powder, and it is possible to adjust the efficiency of carburizing into the molten metal and the slag. As a result, the degree of freedom in maintaining the operation mode according to the operation conditions is expanded.

For example, in an operation state in which the carburizing efficiency into the molten metal is high and the slag forming is not sufficient, the amount of powder entrained in the oxygen jet is adjusted by swinging the lance for powder, and the collision distance ( By taking L ₂ ) longer and lowering the collision speed (V) of the powder, the carburization in the slag that suppresses the carburization into the molten metal increases, and the slag forming can be promoted. . Ensuring proper slag forming according to the operating conditions will suppress heat radiation from the surface of the molten metal, shortening the refining time, reducing power consumption, and preventing the scattering of the molten metal. And suppresses the wear of the upper electrode, greatly contributing to the improvement of the electrode unit consumption.

[0012] 2) The tip of the powder lance can be located at a position outside the furnace (L ₁ ) which is not affected by a rebound splash or the like at the time of cutting, and a large amount of inertness occurs when powder is not blown. Use of gas and the like can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 5 is a plan view showing an outline of a blowing device installed in front of the furnace of the electric furnace main body 6 of this embodiment, and an operating range of the lance 2 for oxygen and the lance 1 for powder. The lance 2 for oxygen and the lance 1 for powder are provided at the tip of the arm 14. The arm 14 is swiveled by a swivel mechanism 15 so that the ends of the lance 2 for oxygen and the lance 1 for powder can be moved to the working port 7.
Can be swung up to an angle (θ ₃ ) from the left end to the right end of the working port 7 by the swing cylinder 16 provided beside the. At this time, the positional relationship between the oxygen lance 2 and the powder lance 1 is as shown by 17-1 and 17-2.

FIG. 1A shows a lance 2 for powder and a lance 1 for powder of an oxygen and powder blowing apparatus to which the present invention is applied.
FIG. 3 is a plan view showing a plan view inserted into the electric furnace. FIG. 1 (b)
Fig. 3 is a partially enlarged view of the tip of the lance when the lance for oxygen and the lance for powder are inserted into the furnace, and the oxygen jet ejected from the tip nozzle of the lance for oxygen and the powder ejected from the lance for powder. FIG. FIG. 1 (c) is a diagram (b)
FIG.

The powder lance 1 is provided below the oxygen lance 2, and the relationship between the nozzle lance 2 and the oxygen lance 2 is shifted rearward by a dimension (L), and is angled on a plane. The oxygen lance 2 is shifted from the center by (θ ₂ ). The tip 3 of the tip provided on the oxygen lance 2 is directed downward by an angle (θ ₁ ) so that the oxygen jet 4 is directed toward the upper surface of the molten metal during operation. Therefore, the powder 5 ejected from the tip of the powder lance 1 collides with the central flow of the oxygen jet 4 ejected from the tip nozzle 3 of the oxygen lance 2, and can be efficiently added to the molten metal. It has become.

FIG. 2A is a plan view of a lance holding hardware provided with the adjusting mechanism of the present invention, and FIG.
It is a side view of (a). The powder lance 1 is sandwiched by upper and lower movable blocks 10-1 and 10-2 placed on a lance holding metal as shown in FIG. It is held by friction. Therefore,
Powder tip nozzle 12 of powder lance 1 and oxygen lance 2
Can be arbitrarily adjusted by releasing the frictional holding of the movable blocks 10-1 and 10-2 provided above and below the powder lance 1.

For example, in order to improve the carburizing efficiency of the powder, the relational dimension (L) between the powder tip nozzle 12 and the oxygen tip nozzle 3 of the powder lance 1 is reduced so that the powder A method of increasing the collision speed (V) can be considered. When the carburizing efficiency is reduced, the operation reverse to the above is performed. Further, by adjusting the angle (θ ₂ ) from the center of the oxygen lance 2 on the plane, the collision range of the powder 5 with the oxygen jet 4 changes, and the powder 5 is caught in the oxygen jet 4 and carburized into the molten metal. Powder 5 can be adjusted.

The angle (θ ₂ ) is adjusted by moving the lower movable block 10-1 provided below the powder lance 1 by jack bolts 9 attached to the side surfaces of the lance holding hardware 8. Since the position of the oxygen lance 2 needs to be held by the lance holding hardware 8, the upper movable block 10-2 provided on the powder lance 1 is divided so as to be slidable.

FIG. 3 is a plan view of the lance 2 for oxygen and the lance 1 for powder during the scrap cutting by the oxygen and powder blowing apparatus of the present invention at the time of melting and the like. 2 shows a state of the scrap 11 at the site of the work port 7 which has been set.

FIG. 4 shows a telescopic device 13 such as a hydraulic cylinder having one end attached to the side surface of the lance holding hardware 8 and the other end attached to the rear end of the powder lance 1. At the time of scrap cutting, a position (L) where there is no influence of nozzle blockage due to rebound splash or the like at the time of cutting the powder lance 1 by the telescopic device 13 such as a hydraulic cylinder.
It is possible to pull out up to ₁ ).

[0021]

As described above, according to the non-consumable oxygen blowing apparatus for oxygen or oxygen-containing gas and charcoal powder of the electric furnace according to the present invention, 1) an appropriate non-consumable lance according to the operating conditions of the lance. The degree of freedom in maintaining the operation form for securing the slag forming height is expanded. As a result, it is possible to prevent the refining time from being prolonged, the power consumption from being deteriorated, and the power consumption from being deteriorated in the upper electrode. Further, damage to the lance itself due to scattered molten metal and slag can be suppressed, and the lance life can be extended. 2) It is possible to reduce a large amount of inert gas or the like for preventing clogging of the tip nozzle of the powder lance, which greatly contributes to reduction of productivity cost, and the effect is extremely large.

[Brief description of the drawings]

FIG. 1 is an explanatory view when an oxygen lance and a powder lance of an oxygen and powder blowing apparatus to which the present invention is applied are inserted into an electric furnace, (a) is a plan layout view, (b) () Shows a partially enlarged view of the tip of the lance, and (c) shows a side view of FIG. (B).

FIG. 2 is a view showing a lance holding hardware of the present invention,
(A) is a plan view, and (b) is a side view of (a).

FIG. 3 shows a lance 2 for oxygen at the time of scrap cutting, melting period and the like by the oxygen and powder blowing apparatus of the present invention.
It is a figure which shows the plane layout drawing of the lance 1 for powders.

FIG. 4 is an explanatory view of a telescopic device used in the present invention.

FIG. 5 is a plan view showing an outline of a blowing device installed in front of a furnace of an electric furnace main body 6 of the present embodiment, and an operating range of a lance 2 for oxygen and a lance 1 for powder.

6A and 6B are views showing a use state of an oxygen lance and a powder lance of an oxygen and powder blowing device inserted into a furnace of a conventionally used electric furnace, and FIG. FIG. 6B is a partially enlarged view of the tip of each lance, and FIG. 6C is a side view of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 powder lance 2 oxygen lance 3 oxygen tip tip 4 oxygen jet 5 powder 6 electric furnace main body 7 working port 8 lance holding hardware 9 jack bolt 10-1 lower movable block 10-2 upper movable block 11 scrap 12 powder Body tip nozzle 13 Telescopic device 14 Arm 15 Rotating mechanism 16 Swing cylinder

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Makoto Takahashi 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Machinery & Plant Business Department (72) Inventor Kiyosuke Mori Tobata, Kitakyushu-shi, Fukuoka 46-59 Nakahara, Nippon Steel Corporation Machinery & Plant Business Department (72) Inventor Kenji Shirakawa 59 Nippon Steel Plant Design Co., Ltd., 46-46 Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Prefecture (72) Inventor Matsushita 1 Shokan Yachiman-cho, Sakai City, Osaka Pref., Kansai Billet Center Co., Ltd. (72) Inventor Yukio Hatanaka, 1 Chikan Yawata-cho, Sakai City, Osaka Pref., Kansai Billet Center Co., Ltd. (58) Field surveyed (Int.Cl. ⁷⁾ , DB name) C21C 7/072 C21C 1/00 F27B 3/22 F27D 3/18

Claims (1)

(57) [Claims] 1. An electric furnace used for melting a metal material, refining a molten metal, etc., through a lance from an upper part of the electric furnace through a lance for accelerating the melting of the metal material and refining the molten metal. In a device for blowing powder, a lance for powder is disposed substantially in parallel below the lance for oxygen, the lance for powder is swingably mounted on the lance for oxygen, and a lance outlet for the lance for oxygen. An oxygen and powder blowing apparatus for an electric furnace, characterized in that a powder lance outlet is mounted so as to be able to move forward and backward.