JPH05255724A - Method for operating smelting reduction furnace and apparatus therefor - Google Patents

Abstract

PURPOSE:To easily discharge slag from a smelting reduction furnace. CONSTITUTION:A trunnion ring 2 is arranged on the outer periphery of the smelting reduction furnace body 1 and also supporting brackets 11 are fixed at the upper outer periphery of the furnace body 1. Plural hydraulic cylinders 12 are inserted between this trunnion ring 2 and the support brackets 11, and by the extension of the hydraulic cylinders 12, the furnace body 1 is ascended and closely stuck to a furnace hole hood 25. Further, by contracting the hydraulic cylinders 12, after descending the furnace body 1, the furnace body 1 is tilted by inclining the trunnion ring 2 to easily discharge the slag from the furnace hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for operating a smelting reduction furnace used for producing molten iron.

[0002]

2. Description of the Related Art Generally, a blast furnace pig iron method is mainly used as a method for producing molten iron. This blast furnace ironmaking method is a nearly completed technology, and has the advantage that a large amount of molten iron can be produced most efficiently, but the blast furnace equipment cost is enormous, and the granular ore cannot be used as it is. There are also disadvantages. Therefore, in place of the blast furnace ironmaking method, other ironmaking methods have been researched and developed, and one of them is that the equipment cost is low, cheap coal and powdered ore can be used, and production is possible. There is a smelting reduction method which has advantages such as easy adjustment and labor saving by automatic control, and it is currently in the spotlight.
Various methods are also under development for such a smelting reduction method, but the essence thereof is to include a preliminary reduction furnace and a smelting reduction furnace, and preliminarily reduce powdered ore in the preliminary reduction furnace to obtain reduced iron and unreduced iron. After the mixture is charged into the smelting reduction furnace and melted, the unreduced ore is reduced.In the smelting reduction furnace, molten slag is generated together with the hot metal, and during normal operation, these are near the bottom of the furnace. It is a pig iron manufacturing method that is provided at the discharge port at a predetermined time interval (for example, Japanese Patent Publication No. 60-2
0441, JP-B-64-5081, JP-B-64-6242, JP-A-58-174513, etc.). By the way, when the slag is taken out together with the hot metal from the discharge port of the smelting reduction furnace using such a smelting reduction method, the discharge port may be blocked due to the viscosity of the slag, etc., and it is necessary to tilt and take out the furnace. Also, after the end of operation,
It is also necessary to tilt the furnace to discharge the remaining hot metal. Therefore, in the furnace described in Japanese Patent Publication No. Sho 64-5081 and Japanese Patent Publication No. Sho 64-6242, the hot metal is discharged while tilting the furnace from another tap hole provided near the furnace top. However, in the tap hole in the smelting reduction furnace described in such publication, since not only the hot metal but also the slag is taken out, the tap hole may still be blocked, and a lance or the like is inserted in the furnace port, and, Since the reducing gas duct for guiding the generated gas in the furnace is also connected, there is a problem that the furnace cannot be tilted easily.

[0003]

Therefore, the present invention was created in order to eliminate the disadvantages of the conventional example. The gist of the present invention is as follows: 1) The furnace body is raised and fixed, and After adhering to the furnace port hood where a reducing gas duct or the like is attached, refining is performed, the furnace body is lowered and tilted, and then slag is discharged from the furnace port of the melting and reducing furnace. In the operating method, 2) a furnace body, a trunnion ring arranged on the outer periphery of the furnace body and interlockingly connected to a tilting device, an elevating device for moving the furnace body up and down with respect to the trunnion ring, In a smelting reduction furnace characterized by comprising a furnace body guide device for controlling a horizontal displacement between the furnace body and the trunnion ring, further 3) a furnace opening of the furnace body, and covering the furnace opening, And, on the outer periphery of the joint with the fixed furnace port hood, Mouth and throat off - claim 2, characterized in that arranged a locking ring for coupling the de engaged detachably
In the smelting reduction furnace.

[0004]

EXAMPLES The operation method of the smelting reduction furnace of the present invention will be described in detail with reference to the examples of the smelting reduction furnace equipment shown in the drawings. 1 is an overall view showing an outline of a smelting reduction furnace, FIG. 2 is an operation state diagram of FIG. 1, FIG. 3 is a detailed view of a main part of FIG. 1, FIG. 4 is a sectional view taken along arrow A of FIG. 3, and FIG. 3 is a detailed view of the B portion of FIG. 3, FIG. 6 is a detailed view of the C portion of FIG. 3, FIG. 7 is a sectional view of the seal portion, and FIG. 8 is an operation explanatory view of the seal portion. In this example, powdered ore (crushed to a particle size of 0.5 mm or less) preliminarily reduced in a preliminary reduction furnace was loaded with coal and lime into a smelting reduction furnace having a furnace diameter of about 3 m and a height of 7 to 10 m. In this furnace, hot metal is charged as seed water in advance, and oxygen gas is blown from the lance inserted from the top of the furnace and the tuyeres opened at the bottom of the furnace, respectively. It is suitable for a smelting reduction furnace that produces molten pig iron at a pressure of ² to 10 kg / cm ² . In these figures,
Reference numeral 1 denotes a smelting reduction furnace (hereinafter simply referred to as a furnace body) similar to a trunnion ring type converter.
The trunnion ring 2 is arranged via the space d. The trunnion ring 2 is supported by a pair of left and right trunnion shafts 3, 3. These trunnion shafts 3 are supported by bearings 3a, but a tilting device 4 is connected to one of the trunnion shafts 3 and this tilting device 4
Is driven by the motor 5. Further, the inside of the furnace body 1 is lined with a refractory material 6, and a plurality of tuyeres 7, 7 ... Are provided at the bottom thereof.
Further, a tap hole 8 having an open / close valve is provided near the bottom of the furnace so that the hot metal 9 and the slag 10 are discharged at predetermined intervals during normal operation. Here, the furnace body 1 is supported by the trunnion ring 2 via an elevating device including a ring-shaped support bracket 11 and a hydraulic cylinder 12. That is, the support bracket 11 is fixed to the furnace body 1 above the arrangement position of the trunnion ring 2, and the support bracket 11 is supported by the eight hydraulic cylinders 12 provided in the trunnion ring 2. One end of the hydraulic cylinder 12 is connected to the lower surface of the support bracket 11 via a pin connecting member 13, and the other end of the hydraulic cylinder 12 is connected to a pin connecting member 14 protruding inward from the lower end of the trunnion ring 2. .. Therefore, the hydraulic cylinder 12 is arranged in the space d formed between the furnace body 1 and the trunnion ring 2. Therefore, in order to prevent the hydraulic cylinder 12 from the heat of the furnace body 1, a heat insulating jacket 15 is interposed (see FIG. 5). Although the support bracket 11 is moved up and down with respect to the trunnion ring 2 by these hydraulic cylinders 12, the support bracket 11, that is, the furnace body 1
The following furnace body guide device is provided in order to regulate the horizontal deviation of the above and to facilitate the vertical movement. That is, on the upper surface of the trunnion ring 2, a pair of left and right elevating guide rods 16 and 16 are provided upright, and the support bracket 11
A guide hole 17 is provided in the front of the guide hole. Also,
On the upper surface of the trunnion ring 2, a pair of upper guide holding pieces 18, 18 are erected at right angles to the installation positions of these elevating guide rods 16, and the support bracket 11 holds a pair of stoppers that face each other. 19 is projected in the horizontal direction. The stopper-19 also functions as a rib.
Further, a pair of guide bars 20 and 20 for preventing tipping are horizontally provided on the outer periphery of the lower portion of the furnace body 1, and a lower guide holding piece 21 facing the trunnion ring 2 is suspended below the trunnion ring 2. ing. And, in the elevating guide rod 16,
As shown in FIG. 6, a cotter insertion port 22 is provided, and a cotter 23 is provided on the support bracket 11 so as to reciprocate by a hydraulic cylinder 24. Next, a bowl-shaped furnace port hood 25 is provided at the upper furnace port of the furnace body 1, and the furnace port hood 25 has a reducing gas duct 26, a lance 27, a sublance 28, and a coal shred. -29 and powder ore sheet 30
Is installed. The furnace port hood 25 is attached to the furnace port hood moving carriage 31. Further, in consideration of the furnace port hood blowing-up force due to the furnace pressure, the furnace port hood 25 is robust in the building during normal operation. It is fixed. This furnace port hood moving carriage 31 travels on a structure beam 32, and can be retracted from the furnace when the refractory material 6 is replaced. Also, a pipe for cooling water and the like are attached to this. Further, the furnace opening and the furnace opening hood 25 are the following sheets.
It is firmly sealed by a reel device. That is, in the furnace, a combustible product gas is generated at a high temperature of several hundreds of degrees Celsius or more and a pressure of several kg / cm ² or more. There is also a danger of gas poisoning of workers, so in order to prevent this from leaking,
As shown in FIG. 7, a lower seat ring 3 is attached to the outer peripheral edge of the furnace opening.
3 and an upper seat ring 34 is provided at the lower edge of the furnace port hood 25. A heat resistant seal material 35 and an elastic seal material 36 are embedded on the lower surface side of the upper sheet ring 34 so as to be joined to the lower sheet ring 33. Also,
The joint between the furnace body 1 and the furnace hood 25 is, for example, 200
Since the gas pressure of ton acts, a lock ring 37, which is rotatably locked to the upper seat ring 34, is provided on the outer periphery of the joint between the seat rings 33 and 34 and around the joint. Inside the lock ring 37, a plurality of lock ring claws 38 are provided, and the lower seat ring 3 is provided.
A plurality of lower seat ring claws 39 are provided on the outer periphery of the cuff 3 so that the claws 38 and 39 can be bayonet-coupled. The connecting surfaces are surfaces inclined with respect to each other as shown by arrows in FIG. 8B to facilitate the connecting and disconnecting. Further, since the lock ring 37 can counter the pressure in the furnace that tends to separate the furnace body 1, the supporting force capacity of the hydraulic cylinder 12 can be reduced.

Next, the operation of this embodiment will be described. When the hydraulic cylinder 12 is extended, the furnace body 1 rises and the furnace opening and the furnace opening hood 25 are joined to each other so that the heat-resistant seal material 35 and Elastic sea
The rule material 36 comes into close contact with the lower sheet ring 33. Then
The lock ring 37 is rotated to connect the claws 38 and 39 to the bayonet as shown by the arrow in FIG. Hot metal 9 is charged into the furnace body 1 in advance as a seed bath. After such preparation, the fine ore preliminarily reduced in the prereduction furnace (not shown) from the fine ore sheet 30, oxygen gas from the lance and tuyere 7,
When coal or the like is blown from the coal shoot 29, the coal is dissolved in the hot metal 9 in the furnace, and the carbon of the coal is oxidized by the oxygen gas to generate oxidation heat. This heat melts the fine ore and reduces it with the carbon in the coal. Therefore, a predetermined refining time (for example, 1
Time), open the tap hole 8 and slag 10 the hot metal 9
Take out with. Since product gas is generated in the furnace body 1 during refining, this product gas is guided to the reduction duct 26 and sent to the preliminary reduction furnace. Since the slag 10 is also taken out during such tapping, the tap hole 8 may be closed due to the viscosity of the slag 10. At that time, the operation is interrupted and the lock ring 37 is rotated to release the bayonet connection of the claws 38 and 39. Next, the hydraulic cylinder 12 is contracted, and the furnace port
The furnace body 1 is lowered from the door 25 to the position of the arc-shaped solid line a shown in FIG. On the other hand, the lifting guide rod 16 has a guide hole 1
The cotter 23 is inserted into the cotter insertion opening 22 by the hydraulic cylinder 24 because it projects upward through 7 When the trunnion ring 2 is tilted by the tilting device 4, the furnace body 1 and the trunnion ring 2 are engaged with the upper guide holding piece 18 and the stopper-19, and the lower guide holding piece 21 and the guide bar 20. Since the horizontal force due to the weight of the furnace body does not act on the hydraulic cylinder 12, the furnace body 1 tilts, and the hot metal 9 and the slag 1 from the furnace mouth are tilted.
You can get 0. Although the furnace body raising / lowering device of the present embodiment is performed by using a hydraulic cylinder, the present invention is not limited to this, and a screw jack may be provided and the furnace body may be raised and lowered by this screw jack.

[0006]

According to the method for operating a smelting reduction furnace of the present invention, since the furnace body is lifted and brought into close contact with the furnace opening hood, unlike the case where the furnace opening hood itself is moved up and down, a reducing gas duct is provided. It is possible to separate the ore ore ore shoe from the furnace hood without removing it from the building. Therefore, the furnace body can be tilted by a labor-free operation, and the slag can be smoothly discharged from the furnace port. As a result, it is possible to easily discharge slag in an emergency. Further, according to the smelting reduction furnace of the present invention, while exhibiting the effects described above,
Further, since the lifting device for raising and lowering the furnace body with respect to the trunnion ring is provided, the tilting device linked to the trunnion ring can be installed on the floor, and the tilting of the furnace body can be reliably performed. Furthermore, according to the smelting reduction furnace of the present invention, since the furnace body and the furnace hood are locked by the lock ring, this lock ring can counteract the pulling down force of the furnace body by the internal pressure of the furnace,
The capacity of the furnace body lifting device can be reduced.

[Brief description of drawings]

FIG. 1 is an overall view showing an outline of a smelting reduction furnace.

2 is an operation state diagram of FIG. 1. FIG.

FIG. 3 is a detailed view of a main part of FIG.

FIG. 4 is a cross-sectional view taken along arrow A in FIG.

FIG. 5 is a detailed view of part B in FIG.

FIG. 6 is a detailed view of a C portion of FIG.

FIG. 7 is a sectional view of a seal portion.

FIG. 8 is an operation explanatory view of a seal portion.

[Explanation of symbols]

 1 Furnace Body 2 Trunnion Ring 4 Tilt Device 10 Slug 11 Support Bracket 12 Hydraulic Cylinder 16 Lifting Guide Rod 17 Guide Hole 18 Upper Guide Clamping Piece 19 Stopper 20 Guide Bar 21 Lower Guide Clamping Piece 25 Furnace Hood 37 Lock Ring

Claims (3)

[Claims] 1. A furnace body is lifted and brought into close contact with a furnace port hood which is fixed and equipped with a reducing gas duct or the like, and then refined, and after the furnace body is lowered and tilted, A method for operating a smelting reduction furnace, which comprises discharging slag from a furnace opening. 2. A furnace body, a trunnion ring arranged on the outer periphery of the furnace body and interlockingly connected to a tilting device, and an elevating device for elevating the furnace body with respect to the trunnion ring.
A smelting reduction furnace comprising: a furnace body guide device that regulates a horizontal deviation between the furnace body and the trunnion ring. 3. A furnace opening of a furnace body and a furnace opening covering the furnace opening and being fixed to the outer circumference of a joint between the furnace opening and the furnace opening. The smelting reduction furnace according to claim 2, wherein a lock ring to be connected is provided.