JP3956430B2 - Steelmaking material supply method and steelmaking material supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for supplying a steelmaking material to a steelmaking furnace for melting steelmaking material such as scrap, and a steelmaking material supply apparatus.
[0002]
[Prior art]
In general, an arc furnace for steelmaking is known as a steelmaking furnace that melts and scraps scraps (steelmaking raw materials) such as scraps of automobile parts and empty cans with high heat. FIG. 9 shows a cross-sectional view of a main part of a conventional sealed steelmaking arc furnace. Reference numeral 2 denotes a furnace body, and 3 denotes a charging bucket which is a steelmaking material supply device.
[0003]
The furnace body 2 is a furnace top charging furnace that melts the scrap 1 using an arc generated by an electrode (not shown) as a heat source. The charging bucket 3 is a container for carrying the scrap 1 and is suspended from a movable overhead crane (not shown). The bottom portion of the charging bucket 3 is a bottom lid 3a that can be freely opened and closed.
[0004]
In the conventional method for supplying steelmaking material, first, a predetermined amount of scrap 1 is charged into a charging bucket 3 in a scrap yard (not shown). Subsequently, the overhead crane is driven, and the charging bucket 3 is moved to a position immediately above the furnace body 2 in a state where the operation is stopped. Here, after sliding the furnace lid 2a of the furnace body 2 to open the opening 2b, the bottom lid 3a of the charging bucket 3 is opened and the scrap 1 is dropped into the furnace body 2. As a result, the scrap 1 is heated by arc discharge, and the molten steel 4 is stored in the bottom of the furnace body 2.
[0005]
[Problems to be solved by the invention]
However, in the conventional steelmaking material supply method and steelmaking furnace, the operation of the furnace is interrupted, the furnace lid 2a is opened, and a large amount of scrap is supplied to the furnace body 2 at a time. For this reason, there existed a fault that the operation process of an arc furnace became complicated and the quantitative supply of the steelmaking material could not be performed.
[0006]
Moreover, since the furnace lid 2a is opened every time the scrap 1 is charged, the heat loss increases and the power supply becomes intermittent. For this reason, the power efficiency is deteriorated, the power consumption rate is remarkably increased, and the voltage fluctuation rate (flicker) is increased.
[0007]
Accordingly, the present invention has been made in view of such circumstances, and quantitatively supplies a steelmaking material without interrupting the operation of the steelmaking furnace, thereby simplifying the operation process and improving heat loss and the like. It is an object of the present invention to provide a method of supplying a steelmaking material and a steelmaking material supply device.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention described in claim 1, when the steelmaking material of the storage tank is supplied to the furnace body through the supply passage by the reciprocating pushing part, the steelmaking material is supplied from the storage tank to the supply passage. An initial supply step for supplying to the staying portion, a first extrusion step for pushing the steelmaking material of the staying portion to the furnace body by advancing the extrusion portion within a range less than the full stroke, and the supply of the pushing portion. It is characterized by comprising a returning step of retreating from the inside of the passage and a second extruding step of advancing the extruding part with a full stroke and extruding the steelmaking material remaining in the staying part to the furnace body.
[0009]
In the first extruding step, the bottom part of the steelmaking material deposited in a triangular shape in the retaining part is pushed out to the furnace body, and the top part collapses. In the returning process, the extruded portion comes out of the steel making material, and the steel making material is deposited at a certain height. Therefore, in the second extrusion step, the steelmaking material is quantitatively extruded into the furnace body by the movement of the extrusion portion.
[0010]
The invention described in claim 2 is the invention described in claim 1, wherein, in the return step, the pushing portion is moved at a speed higher than the moving speed in the first extruding step and the second extruding step. It is characterized by. By performing the return process at high speed, the steelmaking material is continuously supplied to the furnace body.
[0011]
A steelmaking material supply device according to a third aspect of the invention includes a storage tank for storing the steelmaking material, a supply passage for supplying the steelmaking material from the storage tank to the furnace body, and the steelmaking material from the supply passage. It is characterized by comprising an extruding part which can be advanced and retracted to be pushed out to the furnace body, and a control means for alternately moving the extruding part in a range smaller than the full stroke and moving in the full stroke.
[0012]
In this invention, the steelmaking material is supplied from the preheating tank into the furnace body through the supply passage, and is melted and made by high heat in the furnace body. During this operation, by the control of the control means, a first extrusion step of pushing out the steelmaking material to the furnace body by advancing the extruding portion in a range smaller than the entire stroke, and the extruding portion are advanced by the full stroke and remain. The second extrusion process of extruding the steelmaking material to the furnace body is performed alternately.
[0013]
In the first extruding step, the lower hem portion of the steelmaking material deposited in a triangular shape in the retention portion is pushed out to the furnace body, and the top portion collapses and the steelmaking material has a certain height. accumulate. Therefore, in the second extrusion step, the steelmaking material is quantitatively extruded into the furnace body by the movement of the extrusion portion.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Subsequently, an embodiment of a method for supplying a steelmaking material and a device for supplying a steelmaking material according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional view of the main part of a closed-type steelmaking arc furnace according to the present invention. Reference numeral 12 denotes a preheating tank (storage tank), 13 denotes a throat part (supply passage), and 14 denotes a furnace body. It is. Among these, the steel-making material supply device is roughly configured by a preheating tank 12 and a throat portion 13.
[0015]
The preheating tank 12 is a hollow shaft-like container having an upper end opened and serving as an inlet. For example, scrap 1 or HBI (hot briquet iron) that is reduced iron or scrap and HBI that is charged into the furnace body 14 is used. Are stored in a mixed state at an appropriate ratio.
[0016]
Openable and closable movable shelves 21 and 21 are mounted inside the preheating tank 12. The movable shelves 21 and 21 are normally closed to seal the preheating tank 12. The preheating tank 12 is connected to exhaust pipes 22 for discharging exhaust gas. The bottom portion of the preheating tank 12 is gently lowered to the throat portion 13 side, and serves as a scrap cutting chute 23 that is a dropping path for guiding the scrap 1. On the bottom side of the preheating tank 12, an upper extrusion means 31 for extruding the scrap 1 to the throat portion 13 is provided.
[0017]
The upper push-out means 31 includes a bar-like upper pusher 32 that can advance and retreat along the inclination of the upper cutout chute 23, an upper pusher storage chamber 33 in which the upper pusher 32 at the standby position is stored, and an upper portion that drives the upper pusher 32. And a hydraulic cylinder 34.
[0018]
The throat portion 13 has an upper end connected to the bottom side surface of the preheating tank 12 and a lower end connected to a scrap charging port 15 provided at the top of the furnace body 14 to form a supply path for the scrap 1. The throat section 13 also serves as a passage for guiding the high-temperature exhaust gas generated in the furnace body 14 to the preheating tank 12, and is advantageous for reducing the power consumption by preheating the scrap 1 before being charged by the exhaust gas. is there.
[0019]
A lower cutout chute (retention part) 24 that forms a horizontal plane in which the scrap 1 extruded from the preheating tank 12 is temporarily retained is formed in the lower part inside the throat part 13. Lower extrusion means 41 for extruding the scrap 1 on the lower cutout chute 24 is provided.
[0020]
The lower push-out means 41 includes a rod-like lower pusher (extrusion part) 42 that can be moved back and forth horizontally along the lower cutout chute 24, a lower pusher storage chamber 43 in which the lower pusher 42 in the standby position is stored, and a lower pusher 42. And a lower hydraulic cylinder 44 for driving the motor.
[0021]
The entire stroke of the lower pusher 42 is set so as to reach the front end portion of the lower cutout chute 24 when the lower pusher 42 moves forward to the foremost position. This is because the scrap 1 remaining on the lower cutout chute 24 can be pushed out into the furnace body 14 without remaining.
[0022]
As shown in FIG. 2, the steel material supply apparatus includes a drive control unit (control unit) 51 that controls the operation of the upper pusher unit 31 and a movement amount that detects the movement amount and the movement speed of the upper pusher 32. A detection unit 52, a drive control unit (control unit) 53 that controls the operation of the lower push-out means 41, and a movement detection unit 54 that detects the movement amount and movement speed of the lower pusher 42 are provided.
[0023]
These drive control units 51 and 53 are connected to respective signal lines so that signals from the operation monitoring unit 55 are input, and the movement amount detection units 52 and 54 are input to the operation monitoring unit 55. Each signal line is connected.
[0024]
Then, the supply method of the steelmaking material by this invention is demonstrated. This steelmaking material supply method includes an initial supply process, a first extrusion process, a return process, and a second extrusion process.
[0025]
First, in the initial supply step, as shown in FIG. 1, the charging bucket 3 charged with the scrap 1 is lowered to enter the charging port 12 a of the preheating tank 12, and the bucket bottom cover 3 a is opened. As a result, the scrap 1 falls and is stored on the movable shelves 21 and 21.
[0026]
Next, the movable shelves 21 and 21 are opened, and the scrap 1 is charged into the preheating tank 12. Thus, as shown in FIG. 3, the preheating tank 12 is filled with the scrap 1. In this state, the scrap 1 remains in the preheating tank 12 and is not supplied to the throat portion 13.
[0027]
Then, as shown in FIG. 4, the upper pusher 32 is advanced into the preheating tank 12 by the upper hydraulic cylinder 34 (see FIG. 8). As a result, the scrap 1 in the preheating tank 12 is pushed out from the upper cutout chute 23, and a part of it is dropped onto the lower cutout chute 24. The extruded scrap 1 ′ is deposited on the lower cut chute 24 in a triangular cross section.
[0028]
Note that the amount of scrap 1 cut out from the upper cutout chute 23 is proportional to the amount of movement of the upper pusher 32. Therefore, the amount of movement of the upper pusher 32 is appropriately set in advance corresponding to the amount of scrap 1 that can be melted at once in the furnace body 14.
[0029]
In the first extrusion step, as shown in FIG. 5, the lower pusher 42 is moved by a lower hydraulic cylinder 44 within a range smaller than the entire stroke, for example, 0.30 L to 0.85 L with respect to the length L of the lower cutting chute 24. Move forward by a distance (intermediate stroke) (see FIG. 8).
[0030]
By the lower pusher 42, the scrap 1 'accumulated in a triangular shape is pushed out little by little from the tip, that is, the lower hem portion. Further, the lower pusher 42 penetrates into the lower part of the pile of the scrap 1 ′, and the top part of the scrap 1 ′ collapses on the lower pusher 42.
[0031]
In the return step, as shown in FIG. 6, the lower pusher 42 is moved back to the standby position of the lower pusher storage chamber 43 (see FIG. 8). At this time, when the lower pusher 42 comes out of the scrap 1 ″ from the scrap 1 ″ that has collapsed, the scrap 1 ″ falls on the lower cut chute 24 to form a mountain whose upper portion is substantially flat.
[0032]
In this return process, the lower pusher 42 is controlled to move backward at a higher speed than the moving speed of the lower pusher 42 in the first extrusion process and the second extrusion process. Although the scrap 1 is not supplied in the return process, the interruption of the supply of the scrap 1 can be minimized by shortening the time required for the return process.
[0033]
In the second extrusion step, as shown in FIG. 7, the lower pusher 42 is advanced by the lower hydraulic cylinder 44 with a full stroke (see FIG. 8). Since the front end of the lower pusher 42 is set so as to reach the front end of the lower cut chute 24 when the lower pusher 42 moves in the entire stroke, all the scrap 1 ″ remaining on the lower cut chute 24 is completely removed from the furnace body 14 ( 1).
[0034]
Since the scrap 1 ″ is accumulated as a mountain with a flat top, it is quantitatively dropped to the furnace body 14 as the lower pusher 42 moves. The lower pusher 42 is slower than the moving speed in the return process. Since it is set, the scrap 1 is cut out in small amounts and supplied to the furnace body 14.
[0035]
Thereafter, the lower pusher 42 is returned to the standby position of the lower pusher storage chamber 43. This return operation is also performed at high speed, and the interruption of the supply of the scrap 1 can be minimized.
[0036]
One cycle including these initial supply process, first extrusion process, return process, and second extrusion process is sequentially repeated. As described above, the operation process can be simplified, and the scrap 1 is continuously and quantitatively supplied to the furnace body 14 little by little.
[0037]
Further, since the furnace body 14 is not opened, it is sufficient to supply power continuously with little heat loss, power efficiency is improved, power consumption is reduced, and voltage fluctuation rate (flicker) can be suppressed.
[0038]
In FIG. 2, the moving amount and moving speed of the upper pusher 32 and the lower pusher 42 can be appropriately changed by input from the operation monitoring unit 55 shown in FIG. 2 according to the scrap melting amount of the furnace body 14. .
[0039]
The operation monitoring unit 55 is supplied with signals relating to the movement speed and movement amount of the upper and lower pushers 32, 42, and the operator can monitor the operation status of the arc furnace by the display of the operation monitoring unit 55.
[0040]
In this embodiment, the case where the two extruding means 31 and 41 are provided has been described. However, the extruding means may be constituted by only the lower extruding means or may be constituted by three or more extruding means. In this embodiment, the upper and lower pushers 32, 42 are driven by the hydraulic cylinders 34, 44, but other driving means, for example, an electric type may be used.
[0041]
【The invention's effect】
As described above, according to the first aspect of the present invention, after the steelmaking material is formed into a substantially flat mountain in the first extrusion step and the return step, the steelmaking material is extruded into the furnace body in the third extrusion step. Therefore, the steelmaking material can be continuously and quantitatively supplied to the furnace body little by little with a simple operation process. In addition, since it is not necessary to open the furnace body, heat loss is small, power efficiency is improved, power consumption is reduced, and flicker can be suppressed.
[0042]
According to the second aspect of the present invention, the time required for the return process can be shortened, so that the steelmaking material can be continuously supplied to the furnace body.
[0043]
According to the third aspect of the present invention, the steelmaking material is made to be a substantially flat mountain by moving the extruded portion in a range smaller than the entire stroke, and then the steelmaking material is extruded to the furnace body by moving the extruded portion of the entire stroke. Therefore, it becomes possible to supply steelmaking material to the furnace body quantitatively in small portions continuously.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a steelmaking material supply apparatus according to the present invention.
FIG. 2 is a block diagram showing a configuration of a steelmaking material supply device according to the present invention.
FIG. 3 is a cross-sectional view (1/5) showing a method for supplying a steelmaking material of the present invention.
FIG. 4 is a cross-sectional view (2/5) showing a method for supplying a steelmaking material according to the present invention.
FIG. 5 is a cross-sectional view (3/5) showing a method for supplying a steelmaking material according to the present invention.
FIG. 6 is a cross-sectional view (4/5) showing a method for supplying a steelmaking material according to the present invention.
FIG. 7 is a cross-sectional view (5/5) showing a method for supplying a steelmaking material according to the present invention.
FIG. 8 is a diagram for explaining the operation of each pusher in the steelmaking material supply method of the present invention.
FIG. 9 is a view showing a conventional method for supplying a steelmaking material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scrap 2 Furnace 3 Charging bucket 12 Preheating tank 13 Throat part 14 Furnace 15 Scrap inlet 23 Upper cut chute 24 Lower cut chute 31 Upper pushing means 32 Upper pusher 33 Upper pusher storage chamber 34 Upper hydraulic cylinder 41 Lower pushing means 42 Lower pusher 43 Lower pusher storage chamber 44 Lower hydraulic cylinder 51, 53 Drive control unit 53, 54 Movement detection unit 55 Operation monitoring unit

Claims (3)

When supplying the steelmaking material in the storage tank to the furnace through the supply passage by the reciprocating extrusion section, an initial supply step of supplying the steelmaking material from the storage tank to the retention section in the supply passage, and the extrusion section at full stroke A first extruding step of pushing out the steelmaking material of the staying portion to the furnace body in a smaller range, a returning step of retracting the extruding portion from within the supply passage, and advancing the extruding portion with a full stroke. And a second extruding step of extruding the steel making material remaining in the staying portion to the furnace body. 2. The method for supplying a steelmaking material according to claim 1, wherein in the returning step, the extruding part is moved at a speed higher than the moving speed in the first extruding step and the second extruding step. A storage tank for storing steelmaking materials;
A supply passage for supplying the steelmaking material from the storage tank to the furnace body;
An extruding part that can freely advance and retract to extrude the steelmaking material from the supply passage to the furnace body;
Control means for alternately performing movement of the pushing portion in a range smaller than the full stroke and movement of the full stroke;
An apparatus for supplying a steelmaking material, comprising:

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