JP2001098312A - Pellet supplying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pellet supplying device capable of supplying pellet onto a rotary furnace hearth uniformly in the cross direction of the hearth while avoiding the stickiness and the jamming with a simple structure in a reduction furnace or a drier of a direct-reduced iron producing apparatus. SOLUTION: In a device for supplying green ball GB granulated with a pelletizer 43 onto the furnace hearth 50 of the rotary hearth type reduction furnace 30 or the drier 44, a dispersion plate 1 which can uniformly disperse the green ball GB in the cross direction of the furnace hearth as a front step chute part in multi-step chutes equipped in the device, is arranged so that the green ball GB is supplied onto the furnace hearth 50 without staying on the dispersion plate 1 and the other reflecting plate 2 and lower guide plate 3 constituting the multi-step chutes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellet feeder in a rotary bed type reduction furnace or a drying furnace (dryer) of a reduction iron production apparatus for reducing a mixture of a reducing agent and iron oxide in a high-temperature atmosphere of a reduction furnace. About.

[0002]

2. Description of the Related Art In the case of producing reduced iron, generally, first, iron ore powder, coal powder, limestone powder and a binder are humidified and mixed, and granulated to form a wet ball called green ball. Form. Next, after drying the wet ball to some extent (making it into a dry ball), it is heated to a high temperature in a reduction furnace to reduce iron oxide in iron ore with coal (reducing agent), thereby forming reduced iron pellets. Can be generated.

[0003] An example of a conventional reduced iron production apparatus will be described with reference to FIG. In the drawing, reference numeral 30 denotes a doughnut-shaped rotary bed type reduction furnace. A rotary hearth (not shown), which is horizontally continuous in a ring shape, is rotatably driven in the direction shown by the dotted arrow in the furnace chamber of the reduction furnace 30. It is provided to be.

[0006] Raw materials (pellets) are placed on the ceiling of the reduction furnace 30.
A supply device 31 is provided, and the material supply device 3
An apparatus 32 for discharging the reduced raw material is provided adjacent to the upstream side of the apparatus 1. In the figure, reference numeral 33 denotes a burner for heating the furnace, and reference numeral 34 denotes an exhaust gas duct of the reduction furnace 30.

In the figure, reference numeral 41 denotes a group of hoppers for accommodating raw material powder, 41a is for iron ore powder, 41b is for coal powder, 41
c is for binder powder. The raw material powders supplied from the respective hoppers 41a to 41c are mixed by a mixer 42, sent to a pelletizer 43 to produce pellets (green balls) having a diameter of 9 to 12 mm, and dried by a rotary bed dryer (drying oven) 44. After that, it is sent to the raw material supply device 31 of the reduction furnace 30 via the conveyor 45, and is continuously supplied onto the rotating hearth.

[0006] The reduced pellets processed in the reduction furnace 30 are taken out of the furnace in a sealed atmosphere from a screw type discharge device 32, stored in a container 46, and sent to a melting furnace or the like in a subsequent process. I have.

Conventionally, as a pellet supply device (for example, see the raw material supply device 31 of the reduction furnace 30 in the drawing) in the rotary bed type reduction furnace 30 or the dryer 44 as described above, a chute shown in FIGS. And the vibration type shown in FIGS.

According to the chute type shown in FIGS. 8 to 10, when the green balls GB conveyed by the conveyor 45 and the like are supplied onto the hearth 50 of the reduction furnace 30 or the dryer 44, the green balls GB are dried. In the case of the machine 44, the green ball G
In order to prevent drying unevenness of B, in the case of the reduction furnace 30, in order to prevent reduction unevenness, the loading height is uniform in the furnace width direction (arrow A in FIG. 8) and the furnace circumferential direction (arrow B in FIG. 8). Need to be supplied to

For this purpose, first, the green ball G
A box (commonly referred to as a stone box) 51 having a shape obtained by removing the side plate is provided to prevent cracking due to the dropping of B and dispersing in the direction of the arrow A, and a green ball GB of the same material is put into the stone box 51 in advance. In advance, it was used as a cushioning material for the green ball GB that would fall later.

The green ball GB that has fallen into the stone box 51 is
The green ball GB, which is piled up in a mountain shape and spills from the side of the stone box 51, is temporarily stored on the plate 53 and the rubber plate 54 while being guided by the chute 52, and supplied at a uniform height (loading). When the lever 55 is manually moved at the time when it is accumulated to the extent possible, the rubber plate 54 is opened by manually moving the lever 55 in the direction of arrow D, and the green ball GB is moved by the vertically movable cutting gate 56 which can adjust the supply height in the direction of arrow E. It was cut out at a certain height by the hearth 50 moving in the direction. The opening and closing of the rubber plate 54 is only at the beginning of the operation, and remains open during the operation.

According to the vibration type shown in FIGS. 11 to 14, the reduction furnace 30 is formed in a tunnel shape with the furnace wall 60 and the ceiling 61 on both sides rising from the floor, and the hearth 50 is disposed inside. I have. The hearth 50 has wheels 63 on a floor rail 62.
And is in contact with a number of horizontal guide rollers 64 fixedly arranged on the side by a horizontal ring rail 65 on the hearth side, and is rotationally driven by a driving device (not shown).

A water ring groove 66 is provided in the lower part of the furnace wall 60 in a ring shape in the horizontal direction, and a skirt 67 on the furnace wall 60 side is provided.
The skirt 68 on the side of the hearth 50 is immersed in the water sealing groove 66 to form a water seal portion. The furnace chamber 69 is located in the gap between the furnace wall 60 and the ceiling 61 above the water seal portion and the hearth 50, and the inside of the furnace chamber 69 is heated by the burner 33.

The vibration feeder 70 constituting the pellet supply device 31 has the reduction furnace 30 arranged radially over the same, and is provided with a vibration drive device 71. G in the figure
B is a green ball (raw pellet).

As shown in FIGS. 12 and 13, the pallet-shaped flat floor 70a of the vibrating feeder 70 is divided into a plurality of grooves by a plurality of longitudinally extending partition plates 72 from the vicinity of the outlet of the conveyor 45 to the end thereof. , The flat floor 7 in the range overlapping with the hearth 50
In the groove 0a, a sloped boot-shaped drop hole 73 is provided one in each groove in a staggered arrangement.

The boot-shaped front end and the narrow-angled rear end of each drop hole 73 are provided so as to coincide with the same circumferential line in the direction of rotation of the hearth 50. The plurality of boot-shaped drop holes 73 are formed such that the boot length is increased from the side of the conveyor 45 toward the tip end and the inclination angle of the boot is gradually reduced, and the same amount of green flowing through each groove is provided. As the ball GB approaches from the outer peripheral side to the inner peripheral side of the hearth 50, the hearth 50
It is considered that the amount of green ball GB dropped per unit length of the width gradually decreases.

Although not shown, the ceiling 61 of the reduction furnace 30 immediately below the flat floor 70a is provided with a plurality of the drop holes 73.
A similar boot-shaped drop hole is provided, which is slightly larger to fit. With the vibration of the vibration feeder 70, the green ball GB falls from the conveyor 45 onto the flat floor 70a, is separated into a plurality of grooves, and is sent to the front end side.
From the furnace through a drop hole in the ceiling of the reduction furnace, and falls seamlessly onto the entire width surface of the hearth 50 so that the whole is supplied to a uniform thickness.

[0017]

[0008] However, FIGS.
In the case of the chute type shown in FIG. 0, depending on the water content and the surface condition of the green ball GB, the fixation in the stone box 51 is severe and a large mass is formed.
Temporary accumulation in four parts causes sticking, and in the cutout gate 56, the direction of rotation of the hearth 50 (arrow B)
When the green ball GB is cut out at the set height, the green ball GB is pressed down from above, which causes the green ball GB to adhere to the hearth 50 or to cause cracking or clogging. there were.

In the vibration type shown in FIGS. 11 to 14, the green ball GB is dropped to a uniform layer height according to the difference in the peripheral speed between the outer peripheral side and the inner peripheral side of the hearth 50. Therefore, the setting of the shape of the boot-shaped drop hole 73 is complicated, and it is difficult to obtain a uniform layer height of the green ball GB. Further, as shown in FIG. 14, a drop hole 7 is provided at a boundary between the drop hole 73 near the conveyor 45 and the next drop hole 73.
3, the area where the amount of fall is small on the right end side and the area where the amount of fall is excessive on the left end side of the next drop hole 73 occurs. This is a stripe pattern in which the layer height changes in a waveform as shown in FIG. There is a problem that the heat reduction reaction of the green ball GB may be insufficient in a region where the falling amount is excessive, though partially, in some cases.

The present invention has been proposed in view of the above circumstances, and has a simple structure in which pellets are fixed on a rotary hearth in a reduction furnace or a dryer of a reduced iron manufacturing apparatus to avoid sticking and clogging, thereby preventing the pellets from being fixed in the floor width direction. It is an object of the present invention to provide a pellet supply device capable of uniformly supplying the pellets.

[0020]

According to a first aspect of the present invention, there is provided a pellet supplying apparatus for supplying pellets granulated by a pelletizer to a rotary bed type reduction furnace or a hearth of a dryer. The apparatus is characterized in that a dispersion plate capable of uniformly dispersing the pellets in the width direction of the hearth is provided as a former chute portion of a multistage chute disposed in the apparatus.

Further, in the pellet feeder according to the second aspect of the present invention, the dispersion plate has a plurality of guide surfaces in a width direction of the hearth.

Further, in the pellet feeder according to the invention of claim 3, the dispersion plate has a liner having a lower frictional resistance than the base material.

A pellet feeder according to a fourth aspect of the present invention is an apparatus for feeding pellets granulated by a pelletizer onto a hearth of a rotary bed type reduction furnace or a dryer, and a vibratory feeder attached to the apparatus. Is provided with a single drop hole, and the drop hole is constituted by a quadratic curve represented by the following equation. L ₁ = L × (R ² −Rin ² ) / (Rout ² −Rin ² ) where L ₁ : distance in the width direction of the supply device L: total width of the supply device R: position in the radial direction of the supply device from the furnace center Rin: supply The radially innermost position Rout in the width radial direction is the radially outermost position in the supply width radial direction.

The pellet supplying device according to a fifth aspect of the present invention is characterized in that the drop hole is constituted by a group of straight lines approximating the quadratic curve.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings by way of examples.

[First Embodiment] FIG. 1 is a plan view of a pellet feeder in a reduced iron production apparatus according to a first embodiment of the present invention, FIG. 2 is a view taken in the direction of arrows II-II in FIG. 1, and FIG. FIG. 7 and 8 to 1 in these figures.
The same members as those of 0 are denoted by the same reference numerals, and redundant description will be omitted.

The present apparatus is an apparatus for supplying the green balls GB to the rotating hearth 50 at a uniform loading height in the width direction in the rotary bed type reduction furnace 30 or the dryer 44.
This apparatus has a simple plate structure, and is composed of three chute plates of a dispersion plate 1, a reflection plate 2, and a lower guide plate 3. These chute plates are appropriately supported via brackets on support beams 5a to 5c provided between a pair of left and right side walls of the frame structure 4.

The dispersion plate 1 as a pre-stage chute portion is
Three flat guide surfaces 1a, 1b,
Consists of 1c, both sides of the guide face 1a to the center of the guide surface 1b, the angle theta ₁ of 1c is 0 to 30 °, and positioned to form a theta _2, the inclination angle θ _1, θ ₂ is required It is determined according to the supply amount. The green ball GB that has fallen on the dispersion plate 1 spreads along the inclination in the center of the hearth 50 (arrow F) and in the hearth width direction (arrow G).

The reflecting plate 2 is formed in a rectangular shape in plan view having a bent plate portion 2a facing the front end surface of the conveyor 45 or the like.
The falling direction of B is changed and guided so that the supply height in the hearth width direction becomes uniform. Therefore, the green ball G is rotated in the direction of rotation of the hearth 50 (arrow C).
When B enters parallel, the reflector 2 becomes straight without bending. The lower guide plate 3 guides the green ball GB to the hearth 50 finally.
Supply.

Each of the plates 1, 2, and 3 may be provided with an inclination angle of 50 ° or more with respect to the horizontal when supplying a green ball GB having a large amount of water. When adjusting the supply amount to the outer peripheral side, the dispersion plate 1
In addition, the inclination angle of the reflection plate 2 may be variable. The dispersion plate 1 is in the hearth width direction (a direction perpendicular to the arrow C).
May be configured to be movable in parallel with the above, so that the drop position of the green ball GB from the conveyor 45 can be adjusted. Reference numeral 6 in the figure denotes a shielding plate for preventing gas flow from the inside of the furnace.

With this configuration, the conveyor 45
The green ball GB inserted into the pellet supply device from the like passes through the dispersion plate 1, the reflection plate 2, the lower guide plate 3, and
It is supplied onto the hearth 50 of the reduction furnace 30 or the dryer 44.

At this time, the green ball GB falling from the upper part falls over the guide surfaces 1a, 1b, 1c. Therefore, the green ball GB moves along the dispersion plate 1
Green ball GB by dropping in the direction
Will spread evenly in the left-right width direction along the inclination.

Further, in order to adjust the dispersion of the green balls GB in the hearth width direction, a reflecting plate 2 having a part thereof bent is provided to change the sliding direction of the green balls GB in the width direction using the same principle. An even distribution can be additionally adjusted. For example, in FIG.
The angle distribution of the green balls GB supplied in the width direction of the hearth 50 can be made ± 20% or less by making the inclination angles of the angle θ ₁ and θ ₂ from 0 ° to 30 °. it can. The dispersion of the reflection plate 2 is an auxiliary to the dispersion plate 1 and does not need to be divided into three in the width direction unlike the dispersion plate 1.
Two divisions in the width direction plate are sufficient.

Further, since the dispersion plate 1, the reflection plate 2, and the lower guide plate 3 are of a multi-stage chute type, the drop height per stage can be suppressed to as low as about 300 mm.
The crack and deformation of the green ball GB can be prevented.
In addition, the dispersion plate 1, the reflection plate 2, and the lower guide plate 3 include a Teflon liner having the lowest frictional resistance of 0.2 to 0.04, and an Ultra High Molecular Weight liner having the next lowest frictional resistance,
By using what is commonly called a UHMW liner (ultra high molecular weight material liner) or stainless steel, and by setting the inclination angle to 50 degrees or more, even if the green ball GB has a water content close to 10%, the green ball GB can be used. And clogging in the device can be prevented.

Further, the present apparatus has a simple plate structure and is easy to manufacture and maintain. Further, by making the inclination angles of the dispersion plate 1 and the reflection plate 2 variable, it is possible to adjust the dispersion of the height of the green ball GB so as to minimize the variation.

[Second Embodiment] FIG. 4 is a plan view of a pellet feeder in a reduced iron production apparatus according to a second embodiment of the present invention, and FIG. 5 is a view taken in the direction of arrows VV in FIG. In these figures, the same members as those shown in FIGS. 7, 12, and 13 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Vibration feeder (pellet supply device) 70
Is provided along with a vibration driving device (not shown in FIG. 11) in a radially straddling manner with respect to the rotary hearth 50 of the reduction furnace 30, and is provided independently on an end portion projecting outside the hearth 50. An arranged conveyor 45 is provided. The vibrating feeder 70 has a flat floor 7 of a flat pallet shape with no partition.
0a, and a quadratic curved single drop hole 1 is formed on the floor of the flat floor 70a so as to overlap from the outer peripheral edge to the inner peripheral edge of the hearth 50.
0 is provided in the diagonal direction. Also, a similar large single drop hole 10 is provided at the same position on the ceiling 61 of the reduction furnace 30 immediately below the vibration feeder 70.

The single falling hole 10 has the same falling pellet layer height (thickness) per unit hearth area on the hearth 50 throughout the inner circumference and the outer circumference having different peripheral velocities. It is constituted by a quadratic curve represented by the following equation.

L ₁ = L × (R ² −Rin ² ) / (Rout ² −
Rin ² ) where L ₁ : distance in the width direction of the supply device L: total width of the supply device R: radial position of the supply device from the furnace center Rin: radially innermost position in the radial direction of the supply Rout: radially outermost position in the radial direction of the supply width is there.

That is, as shown in FIG. 4, the single drop hole 10 constituted by the quadratic curve extends from the hearth outer periphery exit side intersection of the substantially square section where the vibrating feeder 70 and the hearth 50 overlap. It is configured as a single drop hole concaved in the traveling direction of the hearth 50 (see the white arrow in FIG. 4) between the intersections on the inner circumference entrance side.

With such a configuration, the green balls GB charged through the conveyor 45 from the drying step are:
The vibrating feeder 70 is fed to the feeder tip side with a uniform thickness. Green ball G sent out
B automatically reaches the edge of the single drop hole 10 and falls automatically onto the hearth 50, and is supplied as a continuous film-like flow having a uniform pellet layer height from the front side of the outer periphery to the rear side of the inner periphery of the hearth 50. Is done.

At this time, the single drop hole 10 is calculated in advance so that the height (thickness) of the falling pellet layer per unit area is the same on the entire inner circumferential side and outer circumferential side of the rotating hearth 50. In the quadratic curve, the outer peripheral side of the hearth 50 has a larger inclination, so that more green balls GB are dropped on the outer peripheral side having a higher peripheral velocity, and the hearth 50 is always under normal operating conditions. The green ball GB can be continuously supplied at a constant layer height over the entire width.

Further, since the drop hole 10 is provided as one continuous hole from the outer periphery to the inner periphery of the hearth 50, the variation in the height of the supplied green ball GB layer is maintained as long as the supply of the green ball GB is not interrupted. Will not occur. For this reason,
In the reduction furnace 30, an effect is obtained that enables stable heating and reduction of the green balls GB. Also, when manufacturing the vibrating feeder 70 for supplying the green ball GB, the design and processing of the drop hole 10 become remarkably easy, and a stable green ball GB supply device can be provided.

[Third Embodiment] FIG. 6 is a plan view of a pellet feeder in a reduced iron manufacturing apparatus according to a third embodiment of the present invention.

In this embodiment, the shape of the single drop hole used for the vibrating feeder 70 in the second embodiment is calculated by two calculations.
Single drop hole 10 composed of a group of straight lines approximating a quadratic curve
A is assumed. Other configurations are the same as those of the second embodiment.

In this embodiment, since the single drop hole 10A is formed by linear cutting, the processing of the drop hole 10A can be performed more easily. Other functions and effects are the same as those of the first embodiment.

The present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0048]

As described above in detail, according to the pellet feeder of the first aspect of the present invention, there is provided a device for feeding pellets granulated by a pelletizer onto a rotary bed type reduction furnace or a hearth of a dryer. There is provided a dispersion plate capable of uniformly dispersing the pellets in the width direction of the hearth, as a pre-chute portion of the multi-stage chute disposed in the apparatus, so that stagnation of the pellets on the chute is eliminated, The pellets can be uniformly supplied to the rotary hearth in the floor width direction with a simple structure while avoiding sticking, clogging and cracking.

According to the pellet feeder of the second aspect of the present invention, since the dispersion plate has a plurality of guide surfaces in the width direction of the hearth, in addition to the same operation and effect as the first aspect of the present invention, By changing the inclination angle and the size of each guide surface, there is an advantage that the pellets can be more uniformly supplied in the floor width direction according to the arrangement direction of the conveyor or the like.

According to the third aspect of the present invention, the dispersing plate has a liner having a lower frictional resistance than the base material. There is an advantage that the stagnation of the pellets can be more reliably eliminated.

According to a fourth aspect of the present invention, there is provided an apparatus for supplying pellets granulated by a pelletizer onto a rotary bed type reduction furnace or a hearth of a dryer, which is attached to the apparatus. A single drop hole is provided in the vibrating feeder, and the drop hole is constituted by a quadratic curve represented by the above-mentioned formula. It can be supplied stably at a uniform height in the direction.

According to the pellet supply device of the fifth aspect of the present invention, since the falling hole is constituted by a group of straight lines approximating the quadratic curve, the same operation and effect as those of the fourth aspect of the present invention are obtained. Therefore, there is an advantage that the processing of the drop hole is easy.

[Brief description of the drawings]

FIG. 1 is a plan view of a pellet feeder in a reduced iron manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a perspective view of the same.

FIG. 4 is a plan view of a pellet supply device in a reduced iron production device according to a second embodiment of the present invention.

FIG. 5 is a view taken in the direction of arrows VV in FIG. 4;

FIG. 6 is a plan view of a pellet supply device in a reduced iron production device according to a third embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an apparatus for producing reduced iron.

FIG. 8 is a plan view of a pellet supply device in a conventional reduced iron production device.

9 is a view taken in the direction of arrows IX-IX in FIG.

FIG. 10 is a perspective view of the same.

FIG. 11 is a cross-sectional view of a pellet supply device in a different conventional reduced iron production device.

FIG. 12 is a plan view of the same main part.

FIG. 13 is a view taken in the direction of arrows XIII-XIII in FIG. 12;

FIG. 14 is a view taken in the direction of arrows XIV-XIV in FIG. 12;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dispersion plate 2 Reflection plate 3 Lower guide plate 4 Frame structure 5a-5c Support beam 6 Shield plate 10, 10A Drop hole 30 Reduction furnace 31 Pellet supply device 32 Discharge device 33 Burner 34 Exhaust gas duct 41 Raw material hopper group 42 Mixer 43 Pelletizer 44 Dryer 45 Conveyor 46 Container 50 Hearth 51 Stone box 52 Chute 53 Plate 54 Rubber plate 55 Lever 56 Cutout gate 60 Furnace wall 61 Ceiling 62 Floor rail 63 Wheel 64 Horizontal guide roller 65 Horizontal ring rail 66 Water sealing groove 67 Skirt 68 Skirt 69 Furnace room 70 Vibration feeder M Stripe pattern GB Green ball

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroki Fujioka 4-22, Kannonshinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. Hiroshima Works (72) Inventor Hideaki Mizuki 4-chome, Kannonshinmachi, Nishi-ku, Hiroshima-shi, Hiroshima No. 6-22 Mitsubishi Heavy Industries, Ltd. Hiroshima Works (72) Inventor Keiichi Sato 4--22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima F-term in Hiroshima Research Laboratory Mitsubishi Heavy Industries, Ltd. 4K012 DE01 DE08

Claims (5)

[Claims] An apparatus for supplying pellets granulated by a pelletizer onto a hearth of a rotary bed type reduction furnace or a dryer, wherein the pellets are used as a pre-stage chute section of a multi-stage chute disposed in the apparatus. A pellet feeder, comprising a dispersion plate that can be uniformly dispersed in the hearth width direction. 2. The pellet supplying apparatus according to claim 1, wherein the dispersion plate has a plurality of guide surfaces in a hearth width direction. 3. The pellet supply device according to claim 1, wherein the dispersion plate has a liner having a lower frictional resistance than a base material. 4. An apparatus for supplying pellets granulated by a pelletizer onto a hearth of a rotary bed type reduction furnace or a dryer, wherein a vibratory feeder attached to the apparatus is provided with a single drop hole, A pellet feeder, wherein the holes are formed by a quadratic curve represented by the following equation. L ₁ = L × (R ² −Rin ² ) / (Rout ² −Rin ² ) where L ₁ : distance in the width direction of the supply device L: total width of the supply device R: position in the radial direction of the supply device from the furnace center Rin: supply The radially innermost position Rout in the width radial direction is the radially outermost position in the supply width radial direction. 5. The pellet supply device according to claim 4, wherein said drop hole is constituted by a group of straight lines approximating said quadratic curve.