JPH07150261A - Production of sintered ore and sintering apparatus - Google Patents

Abstract

PURPOSE:To shorten the sintering time and to drastically improve the productivity by arranging a pressure reducing device in a wind box below a pallet in a downward suction type sintering machine and adjusting oxygen-containing gas passing quantity so as to be uniformized in the width direction of the pallet. CONSTITUTION:At the time of producing sintered ore by the downward suction type sintering machine, the pressure reducing devices 20, 20a are arranged in both side wall parts in the width direction of the pallet 8 at the upper part of the wind box 9 below the pallet 8. The negative pressure of the pressure reducing devices 20, 20a is controlled by opening/closing dampers 21, 21a and the negative pressure in the width direction of the pallet is made higher as directing to the central part of the pallet and the oxygen-containing gas passing quantity is adjusted so as to be uniformized in the width direction of the pallet 8 to execute the sintering. By this method, the sintering rate in the width direction of the pallet is equalized and the sintering time can be shortened and the product quality is wholly improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sintered ore and a sintering apparatus which are raw materials for producing hot metal in a blast furnace or the like.

[0002]

2. Description of the Related Art A conventional sinter production process is shown in FIGS.

In the conventional method shown in FIG. 4, the ore which is the main raw material of the sintered ore, the limestone which is the auxiliary raw material, the coke of the fuel, and the sinter raw material in which the return ore is conditioned and granulated are conveyed to the surge hopper 2 and stored. After that, cut out from the drum feeder and shoot 3.
It is charged into the pallet 8 via the and the raw material filling layer 6 is formed. In the case of sintering using iron ore as a main raw material, the thickness of the raw material packed layer is usually 600 mm.

Next, the surface coke of the raw material packed bed 6 is ignited in the ignition furnace 7 to burn the coke while sucking air downward, and the combustion heat sinters the raw material sequentially from the upper layer to the lower layer.

In this conventional method, for example, Japanese Unexamined Patent Publication No.
In Japanese Patent Laid-Open No. 1-86702, a raw material-packed layer close to the inner wall of the pallet is compressed by a pressure roller to increase the bulk density of the raw material-packed layer to make the wind speed in the pallet width direction uniform and to uniformly sinter the pallet width direction. In Japanese Patent Laid-Open No. 57-2973, a vibrating body is inserted in a raw material-packed layer near the inner wall of the pallet to increase the bulk density of the raw material-packed layer to make the wind velocity in the pallet width direction uniform. A method for homogenizing widthwise sintering is described. Regarding the control of the negative pressure of the wind box, there is a method of controlling the negative pressure of the entire wind box by a damper of the entire wind box.

The conventional method shown in FIG. 5 is the exhaust gas circulation sintering method, but it is the same as the conventional method until the surface layer coke of the raw material packed bed 6 is ignited in the ignition furnace 7. Then, the wind box 9 is divided into the mining side and the mine side, and the flue gas containing oxygen-containing exhaust gas or the circulating exhaust gas in which oxygen-containing exhaust gas is mixed with air is supplied to the sintering layer on the mining side from the exhaust gas hood 14. The coke in the raw material-filled layer 6 is sucked to burn, and the combustion heat heats the raw material sequentially from the upper layer to the lower layer. The mine ore side burns the coke in the raw material packed bed 6 while sucking air, and the combustion heat sequentially sinters the raw material from the upper layer to the lower layer.

[0007]

In the conventional method, there is a distribution in which the wind speed in the pallet width direction increases as it approaches the pallet side wall. For this reason, sintering is accelerated closer to the pallet side wall, and as shown in FIG. 6, the sintering rate of the sinter layer closer to the pallet side wall is higher than that in the pallet width direction central part, and the part near the pallet side wall is sintered. Is completed and a sinter cake is made. Since this part of the sinter cake has a smaller ventilation resistance than the sintered layer in the center part of the pallet width direction, air is selectively sucked into the part of the sinter cake on the side wall of the pallet,
The progress of sintering at the center of the pallet width direction becomes extremely slow,
For this reason, the raw material layer 6a in the central portion remains forever, the sintering time is significantly lengthened, and the productivity is significantly reduced.

On the other hand, in the conventional exhaust gas circulation sintering method, the air having a higher oxygen concentration than the exhaust gas is sucked from the upper portion of the pallet side wall or the gap between the pallets into the sintered layer close to the pallet side wall, and the pallet widthwise center is formed. Since air or exhaust gas is less likely to be sucked into the part, the delay in the progress of sintering in the central part becomes longer than in the conventional method, and the productivity is further reduced.

As described above, conventionally, there has been a problem that productivity is lowered because the sintering is delayed. To solve this problem, JP-A-51-86702 or JP-A-57-2973
In the method described in the publication, there is a limit to making the sintering rate in the pallet width direction uniform, and it cannot be said that the method has been sufficiently solved.

It is an object of the present invention to make the sintering rate in the pallet width direction uniform when manufacturing a sintered ore with a downward suction type sintering machine.

[0011]

The gist of the present invention is to provide a pallet 8 in a method for producing a sintered ore by a downward suction sintering machine.
A method for producing a sintered ore, characterized in that sintering is performed while adjusting an oxygen-containing gas aeration amount to be uniform in the width direction of the pallet 8 by a pressure loss device 20 installed in a lower wind box 9, and This is a sintering ore sintering device characterized by having pressure loss devices 20 on both side walls in the width direction of the upper part of the pallet 8 inside the wind box 9 below the pallet 8 of the lower suction sintering machine.

[0012]

In the past, the amount of ventilation of air or circulating gas in the width direction of the pallet was non-uniform, but in the present invention, a pressure loss material is installed on both side walls of the upper part of the wind box at the bottom of the pallet, and suction is performed inside the wind box. The pressure is reduced toward the side wall of the pallet to make it uniform in the width direction of the pallet. Therefore, as shown in the sintering process of the latter half of the present invention in FIG. 3, the sintering speeds in the pallet width direction become equal, the sintering reaction layer 6b becomes equal to the lower layer in the pallet width direction, and the sintering stagnant portion The sintering time is shortened due to the elimination of
Further, since the sintering time is made uniform in the pallet width direction, the quality of the product is improved as a whole.

At least one set of pressure loss devices is arranged on both side walls of the upper part of the wind box in the pallet width direction, and the ventilation amount of the pallet width direction can be uniformly adjusted by adjusting the opening of the damper. One set of pressure drop devices may be installed on the wind box side wall to adjust the air flow between the pallet side wall and the center, but the number of pressure drop devices should be set to make the air flow more uniform in the pallet width direction. It is preferable to increase the number to two or more.

The sintering speed in the width direction of the pallet is determined by visually observing the cross-sectional red heat layer of the lowermost layer of the sinter in the discharge part. If the red heat layer of the pallet side wall is higher than the center of the pallet, the pallet side wall is sintered. Judging that the progress is slow, increase the damper opening and increase the negative pressure of the pressure loss device. On the contrary, if the red heat layer on the side wall of the pallet is located lower than the center of the pallet, it is determined that the progress of sintering on the side wall of the pallet is fast, and the damper opening is reduced to reduce the negative pressure of the pressure loss device.

[0015]

First Embodiment FIG. 1 shows a first embodiment of the present invention.

The sintering process is the same as the conventional one, and the layer thickness is 6
Coke in the surface layer portion of the raw material filling layer 6 of 00 mm was ignited in the ignition furnace 7 and then sintered while sucking air.

A pressure drop device 20, 2 is installed in the wind box 9.
Two sets of 0a are provided. The negative pressure of the pressure loss devices 20 and 20a is controlled by opening and closing the dampers 21 and 21a with an opening / closing device. The negative pressure inside the pressure loss device 20 at the side wall of the pallet is 1100 mmH ₂ O, and the pressure loss device 2 from the center of the pallet.
The negative pressure in 0a was 1300 mmH ₂ O, and the negative pressure in the wind box 9 was 1500 mmH ₂ O. The width of the pallet 8 is 3 m, the width of the pressure drop device is 0.3 m for the pressure drop device 20 on the side wall of the pallet, and the pressure drop device 2 from the center of the pallet is 2.
0a is 0.4 m.

Since the negative pressure in the pallet width direction is increased toward the center of the pallet, the sintering speed in the pallet width direction becomes equal to the lower layer as in the sintering process in the latter half of the present invention shown in FIG. As a result of eliminating the stagnation part of the table, Table 1
As shown in, shortened sintering time, productivity of the conventional method 28.6t / D / m ² than 6.5t / D / m ² high 3
It was significantly improved to 5.1 t / D / m ² .

[0019]

[Table 1]

As described above, the sintering speed in the pallet width direction is determined by the cross-section red heat layer of the lowermost layer of the sinter of the discharge part. If it is determined that the pallet side wall progresses slowly, the pressure loss device 20,
The dampers 21 and 21a of the 20a are opened by the damper opening / closing device to increase the negative pressure of the pallet side wall portion, and if it is determined that the sintering progress of the pallet side wall portion is fast, the dampers 21 and 21a of the pressure drop devices 20 and 20a are opened by the damper opening / closing device. Closed to reduce the negative pressure on the side wall of the pallet.

[0021]

Second Embodiment FIG. 2 shows a second embodiment of the present invention.

The sintering process is the same as the conventional one. After the coke in the surface layer portion of the raw material filling layer 6 is ignited in the ignition furnace 7,
Sintered while sucking air.

The wind box 9 was divided into a mining side and a mine side, and flue gas at 180 ° C. and an oxygen concentration of 15% was supplied to the flue gas introduction pipe 13 of the flue gas hood 14. One set of pressure loss device 20 was provided in the wind box 9. The exhaust gas introduction pipe 13 was installed at five positions in the exhaust gas hood 14. Air was supplied to the exhaust gas introduction pipe 13 so that the oxygen concentration in the exhaust gas hood 14 became 18%.

The negative pressure of the pressure loss device 20 is controlled by opening and closing a damper 21 in switchgear and 1250mmH ₂ O the negative pressure in the pressure loss device 20, the negative pressure in the wind box 9 and 1500mmH ₂ O. The pallet 2 has a width of 5 m, and the pressure loss device 20 has a width of 0.8 m.

Since the negative pressure in the pallet width direction is increased in the central portion of the pallet, the sintering speed in the pallet width direction becomes equal to the lower layer as in the latter half of the sintering process of the present invention shown in FIG. As a result of eliminating the stagnation part, as shown in Table 2, the sintering time was shortened and the productivity was 26.4 t compared with the conventional method.
/ D / m ² than 7.5t / D / m ² high 33.9t / D
Significantly improved to / m ² .

[0026]

[Table 2]

The sintering speed in the width direction of the pallet is determined by the cross-section red heat layer of the lowermost layer of the sintering in the discharge part, as in the first embodiment, and the damper 21 of the pressure loss device 20 is opened / closed by the damper opening / closing device. The negative pressure of the section was raised and lowered.

[0028]

According to the present invention, the sintering in the width direction of the pallet is made uniform, the sintering becomes faster, and the productivity is improved as compared with the conventional method.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a sintering apparatus of the present invention.

FIG. 2 is a cross-sectional view of an example of the sintering apparatus of the present invention.

FIG. 3 is a diagram showing a sintering process of an example of the present invention.

FIG. 4 is a diagram showing a conventional sinter production process.

FIG. 5 is a diagram showing a conventional sinter production process.

FIG. 6 is a diagram showing the progress of sintering in a conventional sintered ore manufacturing process.

[Explanation of symbols]

 1 Sintering raw material 2 Surge hopper 3 Chute 4 Bedding hopper 5 Bedding 6 Raw material filling layer 6a Raw material layer 6b Sintering reaction layer 6c Sinter cake 7 Ignition furnace 8 Pallet 8a Pallet side wall 9 Windbox 10 Circulating gas dust collector 11 Circulating gas blower 12 Circulating gas flue 13 Exhaust gas introduction pipe 14 Exhaust gas hood 15 Dust collector 16 Desulfurizer 17 Blower 18 Chimney 20, 20a Pressure loss device 21, 21a Damper

Claims (4)

[Claims] 1. A method for producing a sintered ore by a downward suction sintering machine, wherein a pressure loss device (20) installed in a wind box (9) below a pallet (8) allows an oxygen-containing gas aeration rate to be increased. A method for producing a sintered ore, which comprises sintering while adjusting so as to be uniform in the width direction of the sinter. 2. An oxygen-containing gas in the width direction of the pallet (8) by adjusting the opening of a damper (21) of a pressure drop device (20) installed in the width direction of the pallet (8) inside the wind box (9). The air flow rate is adjusted, and the air flow rate is adjusted.
A method for producing the sinter according to the description. 3. Sintering characterized by having pressure loss devices (20) on both side walls in the width direction of the upper pallet (8) inside the wind box (9) below the pallet (8) of the lower suction sintering machine. Ore sintering equipment. 4. A pressure drop device (2) having a damper (21).
The apparatus for sintering ore according to claim 3, wherein at least one set of 0) is provided on both side walls in the width direction of the upper pallet (8) inside the wind box (9) below the pallet (8).