JP2001107122A - Discharging device of pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of a product and the working efficiency of an equipment by preventing the lack in drying by surely discharging pellets on a furnace hearth to the outside of the furnace, and also, by preventing the damage to a device, in the discharging device of the pellets. SOLUTION: In a drying furnace 17 of a producing apparatus for reduced iron, plural scrape-off plates 63 are provided as a scrape-off means for sraping off green balls GB stuck on the surface of a pallet 48 between a first pellet discharging part 57 and a second pellet discharging part 58. Then, after discharging the green ball GB which are not stuck on the surface of the pallet 48 at the first pellet discharging part 57, the green balls GB stuck on the surface of the pellet 48 are scraped off with plural scrape-off plates 63 and the green balls GB scraped off, are discharged in the second pellet discharging part 58.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a manufacturing apparatus for manufacturing reduced iron by reducing pellets obtained by granulating a mixed powder of an iron raw material and a reducing agent in a high-temperature atmosphere. The present invention relates to a pellet discharging device for discharging reduced pellets to the outside of a furnace.

[0002]

2. Description of the Related Art When producing reduced iron, first, iron ore powder, coal powder, limestone powder, and a binder are mixed and granulated to form wet balls called green balls. Next, this green ball is dried to some extent in a drying furnace, and then heated to a high temperature in a reduction furnace to reduce iron oxide in iron ore with coal, thereby producing pellet-like reduced iron. it can.

FIG. 11 schematically shows a conventional pellet discharging device in a drying furnace, and FIG. 12 schematically shows a pellet discharging device in a reduction furnace.

In a conventional drying furnace, as shown in FIG. 11, a hearth 002 is formed by a plurality of plate-shaped pallets 001 being continuous in a ring shape inside a drying furnace body (not shown) formed in a donut shape. And is rotatable in the circumferential direction by a driving device (not shown). A pellet supply unit (not shown) for supplying the green balls GB onto the hearth 002 and a pellet for discharging the dried green balls GB dried on the hearth 002 to a predetermined position of the drying furnace body. A discharge unit 003 is provided. That is, each pallet 001 is tiltably supported by the movable body 004 by the support shaft 005 along the width direction, and the cam roller 006 is supported by the guide portion 007. And this guide part 007 is the pellet discharge part 0
A bent portion 008 recessed downward is formed at a position corresponding to 03, and a hopper 009 is disposed below the bent portion 008.

[0005] Accordingly, the green balls GB are supplied from the pellet supply unit onto the hearth 002, and when the hearth 002 rotates at a predetermined speed, the green balls GB are dried by the high-temperature gas supplied into the furnace. Then, the pallet 001 is tilted by the cam roller 006 being guided by the bent portion 008 of the guide portion 007 at the pellet discharging portion 003 of the dried green ball GB, and the mounted green ball GB is moved to the hopper 009.
And is discharged out of the furnace.

On the other hand, in a conventional reduction furnace, as shown in FIG. 12, a ring-shaped hearth 011 is provided in a reduction furnace main body (not shown) formed in a donut shape, and a drive (not shown) is provided. The device can be rotated in the circumferential direction. A pellet supply unit (not shown) for supplying dried green balls GB onto the hearth 011 and a reduced pellet RP reduced on the hearth 011 are discharged to a predetermined position of the reduction furnace body. And a pellet discharge section 012 to be provided. That is, the base end of the support lever 014 is provided on the support shaft corresponding to the pellet discharge portion 012 on the frame 013 of the reduction furnace main body.
It is supported swingably up and down by 015.
A pellet discharge screw 017 is rotatably supported by the bearing 016 on the screw 14. Further, a hydraulic cylinder 018 and a stopper 019 are mounted on the horizontal portion of the frame 013, and the support lever 014 can be swung up and down by the hydraulic cylinder 018. The height of the support lever 014 by the stopper 019, that is, the hearth The height position of the screw 017 for discharging pellets with respect to 011 can be regulated.

Accordingly, the dried green balls GB are supplied from the pellet supply section onto the hearth 011. When the hearth 011 rotates at a predetermined speed, the inside of the furnace is heated by a burner (not shown) to form a high-temperature atmosphere. Become a Green Ball GB
The iron oxide in the iron ore is reduced by the coal to form reduced pellets RP. Then, the reduced pellet RP is dropped laterally by the pellet discharging screw 017 in the pellet discharging section 012, discharged out of the furnace, and packed in a container (not shown).

[0008]

However, in the above-described drying furnace, green balls GB having a particle size of about 10 to 20 mm are dried in a state of being stacked on the hearth 002 to a thickness of several layers. However, the lowermost green ball GB is pressed by its own weight or the upper green ball GB and pressed, or bites into the grating hole of the pallet 001. Then, when the pallet 001 is tilted in the pellet discharge section 003, the green ball GB cannot be discharged to the hopper 009 without dropping while being attached to the pallet 001, and a discharge failure occurs. And green ball GB is pallet 001
When the pellets are returned to the pellet supply section without being adhered to the pellets, the undried green balls GB are supplied on the dried green balls GB, and the flow of the high-temperature gas in the furnace deteriorates. Insufficient drying results in poor product quality.

In the above-mentioned reduction furnace, in order to increase productivity, the inside of the furnace is 1200 in order to make the residence time of pellets in a high-temperature atmosphere as short as possible.
It is heated to a high temperature of 1300C to 1300C. Therefore, a part of the reduced pellets RP is melted by heat generated from the reduced pellets RP on the hearth 011, and the reduced pellets RP may adhere to each other to form a large mass or may be welded on the hearth 011. .
Then, in the pellet discharging section 012, the pellet discharging screw 017 is connected to the large lump or hearth 0 of the reduced pellets RP.
Since the reduced pellets RP deposited on 11 are forcibly discharged to the outside of the furnace, the pellet discharging screw 017 is used.
An abnormal overload acts on the blade, which may cause problems such as damage to the blades and damage to the main body.

The present invention has been made to solve the above-mentioned problems, and it is possible to prevent insufficient drying and the like by reliably discharging the pellets on the hearth to the outside of the furnace, and to prevent the damage of the apparatus to improve the product quality and quality. It is an object of the present invention to provide a pellet discharging device with an improved facility operation rate.

[0011]

According to a first aspect of the present invention, there is provided a pellet discharging apparatus for granulating a mixed powder of an iron raw material and a reducing agent on a hearth moving in a high-temperature atmosphere. In a pellet discharging device that takes out the dried pellets after drying or reduction, a rotary hearth in which a plurality of pallets are continuously supported in a ring shape and each is rotatably supported, and the pellets are supplied to the surface, and the pallet. Pallet tilting means for discharging the loaded pellets downward by tilting the pallet at a predetermined rotation position,
Scraping means provided on the pallet moving direction upstream side of the tilting position of the pallet to scrape the pellets adhered to the pallet surface.

Further, in the pellet discharging device according to the present invention, the first pallet tilting means for discharging the mounted pellets downward by tilting the pallet upstream of the scraping means in the pallet moving direction is provided. And a second pallet tilting means provided downstream of the scraping means in the pallet movement direction to discharge the pellets scraped by the scraping means downward.

In the apparatus for discharging pellets according to a third aspect of the present invention, the scraping means inclines the plurality of scraping plates at the downstream end in the pallet moving direction so as to face the center of the pallet in the width direction. It is characterized by being arranged and configured.

Further, the pellet discharging apparatus according to the present invention is characterized in that pellets obtained by granulating a mixed powder of an iron raw material and a reducing agent on a hearth moving in a high-temperature atmosphere are dried or reduced and then taken out to the outside. In the discharge device, a rotary hearth, which is rotatably supported in a ring shape and is supplied with the pellets on its surface, is disposed along a width direction at a predetermined rotation position of the rotary hearth. A discharge screw for discharging the loaded pellet to the side, supporting means for supporting the discharge screw rotatably and movably in the vertical direction, and a bias for reducing the weight of the discharge screw by biasing the discharge screw upward. Means.

According to a fifth aspect of the present invention, there is provided an apparatus for discharging pellets, comprising: detecting means for detecting upward movement of the discharge screw; and alarm means for issuing an alarm when the detecting means detects upward movement of the discharge screw. Are provided.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic front view of a pellet discharging device according to a first embodiment of the present invention, FIG. 2 is a schematic plan view showing a pallet support structure, and FIG. 3 is a schematic plan view showing a mounting structure of a scraping plate. FIG. 4 schematically shows the mounting state of the scraping plate in FIG.
FIG. 5 schematically shows a modified example of the scraping plate, FIG. 6 is a schematic plan view showing a modified example of the mounting structure of the scraping plate, and FIG. 7 shows a reduction in which the pellet discharging device of the present embodiment is applied to a drying oven. The outline showing the whole structure of an iron manufacturing device is shown.

In the present embodiment, the apparatus for discharging pellets of the present invention is applied to a drying furnace used in an apparatus for producing reduced iron.

First, a process for producing reduced iron according to the present embodiment will be briefly described. As shown in FIG. 7, first, iron ore powder (iron raw material), coal powder (reducing agent), and limestone powder, which are raw materials for pellets, are placed in hoppers 11, 12, and 1, respectively.
3 and mixed with the binder supplied from the hopper 14 by the mixer 15. Next, the mixed powder is granulated by a pelletizer 16 into green balls (raw pellets) GB having a diameter of 10 to 20 mm, placed in a drying furnace 17, and dried by exhaust gas from a reduction furnace 19 described later. Then, the dried green balls GB are supplied to the reduction furnace 19 through the conveyor 18 by the pellet supply device 31.

The inside of the reduction furnace 19 is heated by a burner 32 and maintained in a high-temperature atmosphere, and the exhaust gas inside is discharged from an exhaust duct 33. Therefore, the green ball GB is heated to a high temperature when moving inside the reduction furnace 19, and the iron oxide in the iron ore is reduced by the coal to generate reduced iron in a pellet form. Then, the reduced pellets are carried out of the reduction furnace 19 by the pellet discharging device 34 and stored in the container 20.

The exhaust gas discharged from the exhaust duct is cooled by a water spray type primary cooler 21 and then sent to a heat exchanger 22, where it exchanges heat with air sent by a blower fan 23. Then, it is cooled again by the water spray type secondary cooler 24. The air heated by the heat exchanger 22 is sent to the reduction furnace 19 and supplied to the furnace together with the fuel. On the other hand, the exhaust gas cooled by the secondary cooler 24 is sent to the drying furnace 17 by the fan 25, and becomes the air for drying the green balls GB as described above. And
The exhaust gas discharged from the drying furnace 17 is purified by a dust collector 26 and further sent to a chimney 28 by an exhaust fan 27.
Released to the atmosphere after desulfurization.

Here, the drying furnace 17 will be described in detail. As shown in FIGS. 1 to 3, a drying furnace main body (not shown) formed in a donut shape has inner and outer portions 2 along the same direction.
It is supported by a plurality of guide rollers 41 and 42 in a row, and can be rotationally driven by a driving device (not shown). In addition, small and large diameter ring frames 43, 44 are arranged at predetermined intervals in the drying furnace main body, and the lower surfaces of the ring frames 43, 44 have rotating shafts 4 extending along the radial direction.
5 are wound around at predetermined intervals in the circumferential direction, and the end of each rotating shaft 45 is connected to the bearing 4 of each ring frame 43, 44.
6 and 47 rotatably supported. A large number of pallets 48 are arranged between the ring frames 43 and 44 in the circumferential direction and located above the respective rotation shafts 45.
The lower surface of each pallet 48 is fixed to the rotating shaft 45,
The pallet 48 is mounted on the ring frame 43 together with the rotating shaft 45.
44 is rotatable.

The plurality of pallets 4 arranged in parallel in the circumferential direction
The hearth 49 is formed by continuous ring shapes 8 in a horizontal state, and ring rails 50, 51 fixed to the lower surfaces of the respective ring frames 43, 44 are supported on a plurality of guide rollers 41, 42. Accordingly, the hearth 49 can rotate together with the ring frames 43 and 44. on the other hand,
A horizontal roller 52 is mounted on the inner ring frame 43, and is rotatable on a ring-shaped wall rail 53 fixed to a furnace support frame (not shown).

Each pallet 48 is fixed to the rotating shaft 45 so as to be shifted forward in the pallet moving direction. A cam lever 54 is provided at the shaft end of each rotating shaft 45 projecting outward from the outer ring frame 44. One end is fixed, and a cam roller 55 is attached to the other end of the cam lever 54. A ring-shaped upper guide rail 56 is disposed above and corresponding to each cam roller 55. In other words, the pallet 48 has its rotating shaft 45 shifted forward in the pallet movement direction, and therefore, the pallet 48 has a weight shown in FIG.
A clockwise rotation force acts on the pallet 48 at this time, and the pallet 48 is horizontally supported by a stopper (not shown).

At a predetermined position of the drying furnace 17, a pellet supply unit (not shown) for supplying green balls (raw pellets) GB onto the hearth 49, and dried pellets dried in the hearth 49 are provided. First and second pellet discharging portions 57 and 58 for discharging to the outside are provided. That is, a tilting portion 56 a is formed so that the upper guide rail 56 is bent downward so as to correspond to the first pellet discharging portion 57, and the upper guide rail 56 is lowered corresponding to the second pellet discharging portion 58. A tilting portion 56b bent so as to be concave is formed.
And each tilting portion 56a, 5 of the upper guide rail 56
A lower guide rail 59 of the same shape is provided below 6b. A cam roller 55 is movably supported between the upper guide rail 56 and the lower guide rail 59.
The tilt angle of the tilting portion 56b is larger than that of the tilting portion 56a of the upper guide rail 56. On the other hand, hoppers 60, 61 are disposed below the first and second pellet discharge sections 57, 58.

Accordingly, when the pallet 48 moves to reach the first pellet discharging portion 57 or the second pellet discharging portion 58, the cam roller 55 is guided by the tilting portions 56a, 56b of the upper guide rail 56 and the lower guide rail 59. As a result, the rotating shaft 45 rotates counterclockwise in FIG. 1, so that the pallet tilts by a predetermined angle via the cam lever 54, and the green ball GB on the pallet 48 is
0,61. Here, the cam lever 54, the cam roller 55, and the respective tilting portions 56a and 56b of the upper guide rail 56 constitute a pallet tilting means.

In such a drying furnace 17, the green balls GB are dried in a state where the green balls GB are stacked on the hearth 49 to a thickness of several layers. It is pressed by the green ball GB and pressed against the surface of the pallet 48. Therefore, in the present embodiment, between the first pellet discharging section 57 and the second pellet discharging section 58, a scraping means for scraping the green ball GB attached to the surface of the pallet 48 is provided.
The scraping means includes a plurality (six in the present embodiment) of scraping plates 63 hanging from the ceiling 62 of the drying furnace main body.
The downstream end of the pallet 48 in the moving direction is inclined so as to face the center of the pallet 48 in the width direction. Specifically, as shown in FIG. 4, the horizontal support plate 6 is provided by a plurality of vertical support plates 64 suspended from the ceiling 62.
5 are arranged in the width direction of the pallet 48, and the upper end of each scraping plate 63 is attached to this horizontal support plate 65 via an angle plate 66 by bolts (nuts) 67. 63 and the pallet 48 (hearth 4
A slight gap is provided between the surface and the surface of 9). Each scraping plate 63 is attached at a predetermined angle (approximately 30 degrees) with respect to the moving direction of the pallet 48, so that the entire area of the pallet 48 in the width direction can be scraped.

Accordingly, the pallet 48 is tilted by the first pellet discharging portion 57 to drop the green ball GB into the hopper 60, but the green ball GB adhering to the surface of the pallet 48 moves together with the pallet 48 as it is. Then, the pallet 48 is scraped by the plurality of inclined scraping plates 63, and the pallet 48 is tilted by the second pellet discharge unit 58 to transfer the remaining green balls GB to the hopper 64.
Can be dropped.

In the drying furnace 17 configured as described above, as shown in FIGS. 1 to 3, when the plurality of guide rollers 41 and 42 are driven by the driving device, the ring rails 50 and 5 are driven.
A plurality of pallets 48 constituting a hearth 49 together with the ring frames 43 and 44 are rotatingly moved in a direction indicated by an arrow at a predetermined speed through the ring 1, and the exhaust gas of the reduction furnace 19 is cooled to a predetermined temperature in the furnace. It is supplied and discharged and has a high temperature atmosphere. In this state, the green balls GB are supplied from the pellet supply unit onto the hearth 49, that is, on each pallet 48, and are dried while moving in the high-temperature atmosphere. Then, the dried green balls GB are supplied to the first and second pellet discharge units 57 and 58.
From the furnace.

That is, first, when the pallet 48 on which the dried green balls GB are loaded reaches the first pellet discharging portion 57, the cam roller 55 is guided by the tilting portions 56a of the upper guide rail 56 and the lower guide rail 59. The pallet 48 is tilted by a predetermined angle via the cam lever 54 and the rotating shaft 45. Then, the pallet 48 is inclined for a predetermined period, and the mounted green ball GB is moved to the hopper 60.
Is dropped. At this time, the lowermost green ball GB stacked on the pallet 48 is
The green ball GB may adhere to the surface of the hopper 60 and does not fall onto the hopper 60. Then, when the tilted pallet 48 passes through the first pellet discharging section 57, the cam roller 55 is guided by the upper guide rail 56 and the lower guide rail 59 and returns to a horizontal state.

Next, the green ball GB attached to the surface of the pallet 48 moves as it is with the pallet 48,
By coming into contact with the plurality of inclined scraping plates 63, they are peeled off and pass between the scraping plates 63. And
When the green ball GB attached to the surface becomes free on the pallet 48 and the pallet 48 on which the green ball GB is placed reaches the second pellet discharging section 58, the same as in the case of the first pellet discharging section 57. , The cam roller 55 is a tilting portion 56 a of the upper guide rail 56 and the lower guide rail 59.
The cam lever 54 and the rotating shaft 45
, The pallet 48 tilts by a predetermined angle. Then, the pallet 48 is inclined for a predetermined period, and the green ball GB is dropped into the hopper 61. Further, at this time, the tilting portion 56b has a larger tilt angle than the tilting portion 56a, so that the tilting speed of the pallet 48 is increased, and the discharge of the green ball GB is promoted. When the tilted pallet 48 passes through the second pellet discharging section 58,
The cam roller 55 is guided by the upper guide rail 56 and the lower guide rail 59 and returns to a horizontal state.

As described above, in the pellet discharging device of the present embodiment, the green ball GB attached to the surface of the pallet 48 is scraped between the first pellet discharging portion 57 and the second pellet discharging portion 58 in the drying furnace 17. A plurality of scraping plates 63 are provided as scraping means for removing. Therefore,
Green ball GB not attached to the surface of pallet 48
Is discharged by the first pellet discharging section 57, and then the pallet 4
8 can be scraped off by a plurality of scraping plates 63, and the GBs scraped off by the second pellet discharger 58 can be discharged. The deterioration of the quality of the product can be prevented by preventing the deterioration of the flow of the high-temperature gas in the inside.

In the above embodiment, a plurality of scraping plates 63 are provided as the scraping means at a predetermined angle with respect to the moving direction of the pallet 48, but the present invention is not limited to this structure.

That is, as shown in FIG. 5 (a), a horizontal support plate 65 is disposed below the ceiling 62 of the drying furnace main body in the width direction of the pallet 48, and the horizontal support plate 65 is angled. The upper end of the scraping plate 71 is attached by bolts (nuts) 67 via the plate 66. In the case of the present embodiment, the scraping plate 71 is formed by laminating three plates having high corrosion resistance, for example, three stainless plates, and between the lower end of the central stainless plate and the surface of the pallet 48 (furnace floor 49). A slight gap is provided. With this configuration, the elasticity of the lower portion of the scraping plate 71 is increased, and when the green ball GB attached to the pallet 48 is peeled off, the scraping plate 7 is removed.
1 can be prevented from being damaged. In this case, as shown in FIG. 5B, a number of thinner stainless steel plates are stacked, and a slight gap is provided between the lower end of the stainless steel plate at the center and the surface of the pallet 48 (hearth 49). Scraping plate 72
May be configured.

As shown in FIG. 6, a pair of scraping plates 63 located at the center in the width direction of the pallet 48 and facing in opposite directions are displaced from each other in the front and rear directions of movement of the pallet 48. Thus, the entire area in the width direction of the pallet 48 may be scraped.

Further, in the above-described embodiment, the first pellet discharging section 57, the scraping means (scraping plate 63), and the second pellet discharging section 58 are disposed in the drying furnace 17 along the moving direction of the pallet 48. First, the green balls GB that have not adhered to the pallet 48 are discharged, then the adhered green balls GB are peeled off, and then the peeled green balls GB are discharged. However, in the drying furnace 17, along the moving direction of the pallet 48, the scraping means (the scraping plate 63), the second pellet discharging portion 58
May be arranged so that all the green balls GB pass through the scraping means (scraping plate 63) to peel off the green balls GB attached to the pallet 48, and then discharge all the green balls GB. .

In the above embodiment, the pellet discharging device of the present invention is applied to the drying furnace 17.
9 may be applied. FIG. 8 is a schematic side view of a pellet discharging device according to a second embodiment of the present invention, FIG. 9 is a schematic front view of the pellet discharging device, and FIG. 10 is a schematic diagram illustrating a support structure of a pellet discharging screw. Note that members having the same functions as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

In the reduction furnace 19, as shown in FIGS. 8 to 10, a pair of parallel rails 82
Are laid in a ring shape. On the other hand, a ring-shaped hearth 84 is fixed to the upper surface of the ring-shaped rotating body 83, and a pair of left and right wheels 85 rotatable on rails 82 is fixed to the lower surface of the rotating body 83 in the circumferential direction. Are installed along. Further, a frame (not shown) is provided so as to cover the hearth 84 from above to form a donut-shaped high-temperature space, and a horizontal guide roller 87 fixed to the base is provided.
The rotating body 83 is guided through a horizontal ring-shaped guide rail 88 fixed to the rotating body 83, and the hearth 84 can be rotated by driving and rotating the rotating body 83 by a driving device (not shown).

A water seal portion 91 is attached to the left and right furnace walls 86 by a water seal.
2 and the lower end of the skirt 93 of the hearth 84 are submerged in the water seal portion 91.

At a predetermined position of the reduction furnace 19, a pellet supply device 34 for supplying green balls GB onto a hearth 84,
Reduced pellets (reduced iron) RP reduced in the hearth 84
A pellet discharging device 35 that discharges to the outside is provided adjacently. In the pellet discharging device 35, the base ends of the L-shaped support levers 95 are respectively supported on the left and right vertical frames 94 of the above-described frames by a support shaft 96 so as to be swingable up and down. The screw 9 for discharging pellets across the hearth 84 in the width direction
The shaft portion 7 is rotatably supported by a bearing 98.
A driving pulley 99 is fixed to the pellet discharging screw 97, and the hearth 84 is driven by a driving device (not shown).
Can be driven to rotate at a speed corresponding to the rotation speed.

The upper ends of two support rods 100 are fixed to the lower surface of each support lever 95, and a positioning nut 102 is screwed to the screw portion 101.
On the other hand, the horizontal frame 1 located below each support lever 95
03 has two through holes 1 against each support rod 100.
04 are formed, and washers 105 are fixed at the same positions as the respective through holes 104. Then, a compression spring 106 as urging means is sandwiched between the washer 107 and the washer 105,
Inserting the support rod 100 from above and positioning nut 1
When the 02 comes into contact with the washer 107, the pellet discharging screw 97 is elastically supported by the frame via the support lever 95. The support lever 9
5 and the screw 97 for discharging pellets
The position of the positioning nut 102 is adjusted so that the elastic force P of the compression spring 106 becomes small. The compression spring 1
It is desirable that the elastic force P of 06 is adjusted to about 1/2 with respect to its own weight of the support lever 95 and the screw 97 for discharging the pellets, and the elasticity P is such that the pellets not adhered to the hearth 84 can be reliably discharged. Set to force.

A hydraulic cylinder 108 and a stopper 109 are mounted on the horizontal frame 103, and the hydraulic cylinder 1
08 is connected to the distal end of the support lever 95. The hydraulic cylinder 108 moves the pellet discharging screw 97 upward through the support lever 95 by the expansion and contraction driving thereof to the standby position where the pellet discharging screw 97 is located above the hearth 84.
It can be moved to an operating position close to. The stopper 109 defines the operating position of the screw 97 for discharging pellets. Further, the horizontal frame 103 is provided with a detection sensor (proximity sensor, positioner, or the like) 111 for detecting the height position of the support lever 95 for the horizontal frame 103, that is, the pellet discharging screw 97. An alarm device 112 that issues an alarm when the upward movement of the pellet discharging screw 97 is detected based on the detection result of the detection sensor 111 is connected to the device 111.

When the green ball GB is reduced in the reduction furnace 19 having the above-described structure, the hydraulic cylinder 1
08, the support lever 95 is moved downward by contracting,
In addition, the pellet discharging screw 97 at the upper standby position is moved to the operating position close to the surface of the hearth 84, and the stopper 109 regulates the downward movement of the pellet discharging screw 97 from the operating position. Then, the compression spring 106 is moved by the positioning nut 102 so that an elastic force smaller than its own weight acts on the pellet discharging screw 97 and the like.
Is adjusted. Then, at the same time when the operation of the reduction furnace 19 is started or the preparation is completed, the supply and discharge of the hydraulic pressure to and from the hydraulic cylinder 108 are set to the free state.

When the operation of the reduction furnace 19 is started, the hearth 84 rotates at a predetermined speed, and the inside of the furnace is brought into a high temperature atmosphere by the burner 32. In this state, green ball GB
Is supplied from the pellet supply unit onto the hearth 84, and while moving in the high-temperature atmosphere, the iron oxide in the iron ore is reduced by the coal by the radiant heat of the high-temperature gas to become reduced iron. Then, the reduced green balls GB (reduced pellets RP) are discharged outside the furnace by the pellet discharging screw 97 in the pellet discharging section 34.

The reduced pellets R are placed on the hearth 84.
A part of P may be melted and adhere to the surface to form a pellet mass. When the pellet mass adhering to the hearth 84 reaches the pellet discharging device 35, the pellet discharging screw 97 runs up without being able to discharge the pellet mass outside the furnace. That is, the pellet discharging screw 97
Is reduced in weight by the elastic force P of the compression spring 106, and is easily lifted upward together with the support lever 95 by the reaction force of collision with the pellet mass to escape.

Then, the detection sensor 111 detects the upward movement of the pellet discharge screw 97, and the alarm device 112 issues an alarm according to the amount of movement of the pellet discharge screw 97. That is, if the upward movement amount of the pellet discharge screw 97 is equal to or more than a predetermined amount, it is determined that the pellet mass is relatively large, and a warning is issued to warn the user of confirmation of the operating conditions of the reduction furnace 19, and the operation is performed if necessary. To stop. Then, an operator performs an inspection work of the reduction furnace 19, removes a pellet lump adhering on the hearth 84, and performs an abnormal recovery action.

As described above, in the pellet discharging device of the present embodiment, the pellet discharging screw 9 in the reduction furnace 19 is used.
7 is supported by a support lever 95 so as to be tiltable upward, and the compression spring 106 urges the support lever 95 and the pellet discharge screw 97 and the like upward to reduce their own weight. Therefore, if there is a pellet mass adhering to the hearth 84, the pellet discharging screw 97 can be easily lifted up with the support lever 95 by the reaction force of the collision with the pellet mass and escape, thereby preventing damage and the like. it can. Then, the detection sensor 111 detects the upward movement of the pellet discharging screw 97 and detects the alarm device 1.
When the alarm 12 is issued, the operation of the reduction furnace 19 is stopped, and the operator can immediately perform recovery measures of the reduction furnace 19.

In the above-described embodiment, two compression springs 106 are provided on the left and right support levers 95 as urging means. However, the number is not limited, and the number of the support springs is not limited. May be set as appropriate according to the shape and weight of the device. Further, instead of the compression spring 106, a tension spring, a torsion coil spring, a hydraulic cylinder, or the like may be used as the urging means in consideration of the mounting position.
08 may be applied with hydraulic pressure so that a predetermined extension force is applied.

[0049]

As described above in detail in the embodiment, according to the pellet discharging device of the first aspect of the present invention,
In a pellet discharge device that removes pellets obtained by drying or reducing pellets obtained by granulating a mixed powder of an iron raw material and a reducing agent on a hearth moving in a high-temperature atmosphere, a plurality of pallets are continuously formed in a ring shape on the surface. Pallet tilting means for rotatably supporting the rotary hearth to which the pellets are supplied and tilting the pallet at a predetermined rotation position to discharge the loaded pellets downward, and a pallet upstream from the tilting position of the pallet Since the scraping means for scraping the pellets attached to the surface was provided, the pellets attached to the surface of the pallet were scraped off by the scraping means, and the pallet was tilted to discharge all the pellets. Improving product quality by preventing insufficient drying due to deterioration of the flow of high-temperature gas inside the furnace by reliably discharging it outside the furnace Rukoto can.

According to the pellet discharging device of the second aspect of the present invention, the first pallet tilting means is provided upstream of the scraping means in the pallet moving direction, and the second pallet tilting downstream of the scraping means is provided. Since the scraping means discharges the pellets scraped downward by the means, the pellets not adhered to the surface of the pallet are discharged, and then the pellets adhered to the surface of the pallet are scraped and discharged. Thus, the processing amount of the scraping means is reduced, the load is reduced, and the life of the scraping means can be extended.

According to the third aspect of the present invention, the scraping means is configured such that the plurality of scraping plates are inclined such that the downstream ends of the plurality of scraping plates in the pallet moving direction face the center of the pallet in the width direction. Since it is arranged and configured, all the pellets attached to the surface of the pallet are scraped and moved to the center side of the pallet, whereby the pellets can be reliably discharged.

According to the apparatus for discharging pellets of the present invention, the pellets obtained by granulating the mixed powder of the iron raw material and the reducing agent on a hearth moving in a high-temperature atmosphere are dried or reduced and then discharged to the outside. In the discharge device of the pellets to be taken out, the rotary hearth in which the pellets are supplied to the surface in a ring shape is rotatably supported, and the discharge screw for discharging the loaded pellet to the side is rotated at a predetermined rotation of the rotary hearth. The discharge screw is rotatably supported by the support means so as to be rotatable and vertically movable, and is biased upward by the biasing means to reduce its own weight. When the discharge screw collides with the pellet mass adhering to the hearth, the collision reaction force easily causes the discharge screw to be lifted upward and to escape, thereby preventing damage to the discharge screw. It is possible to stop.

According to the apparatus for discharging pellets of the present invention, the detecting means for detecting the upward movement of the discharge screw, and the alarm means for issuing an alarm when the detecting means detects the upward movement of the discharge screw. When the discharge screw collides with the pellet mass adhering to the hearth and moves upward, the detecting means detects the upward movement of the discharge screw and an alarm device issues an alarm, thereby operating the reduction furnace. Is stopped, the operator can immediately perform a recovery operation of the reduction furnace, and the operation rate of the reduction furnace can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a pellet discharging device according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view showing a pallet support structure.

FIG. 3 is a schematic plan view illustrating a mounting structure of a scraping plate.

FIG. 4 is a schematic view illustrating a mounting state of a scraping plate.

FIG. 5 is a schematic view illustrating a modified example of a scraping plate.

FIG. 6 is a schematic plan view illustrating a modified example of the mounting structure of the scraping plate.

FIG. 7 is a schematic diagram illustrating an entire configuration of a reduced iron manufacturing apparatus in which the pellet discharging device of the present embodiment is applied to a drying furnace.

FIG. 8 is a schematic side view of a pellet discharging device according to a second embodiment of the present invention.

FIG. 9 is a schematic front view of a pellet discharging device.

FIG. 10 is a schematic view showing a support structure of a screw for discharging pellets.

FIG. 11 is a schematic view of a conventional pellet discharging device in a drying furnace.

FIG. 12 is a schematic view of a pellet discharging device in a reduction furnace.

[Explanation of symbols]

 17 Drying furnace 19 Reduction furnace 31 Pellet supply part 32 Burner 33 Water seal part 34 Pellet discharge part 43, 44 Ring frame 45 Rotating shaft 48 Pallet 49 Hearth floor 54 Cam lever 55 Cam roller 56 Upper guide rail 56a, 56b Tilting part 57 First pellet Discharge part 58 Second pellet discharge part 59 Lower guide rail 60, 61 Hopper 84 Hearth 86 Furnace wall 95 Support lever 97 Pellet discharge screw 100 Support rod 105, 107 Washer 106 Compression spring 108 Hydraulic cylinder 109 Stopper 111 Detection sensor 112 Alarm apparatus

 ──────────────────────────────────────────────────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 City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Laboratory F-term (reference) 4K001 AA10 BA02 CA23 GA10 GA12 GB02 4K012 CA08 DE02 DE08 4K055 AA00 BA05 EA07 GA01

Claims (5)

[Claims] 1. A pellet discharging device for drying or reducing pellets obtained by granulating a mixed powder of an iron raw material and a reducing agent on a hearth moving in a high-temperature atmosphere, and extracting the pellets to the outside, the plurality of pallets are formed in a ring shape. A rotary hearth which is continuously rotatably supported and the pellets are supplied to the surface thereof; and a pallet tilting means for tilting the pallet at a predetermined rotation position of the pallet to discharge the loaded pellets downward. And a scraping means provided on the pallet moving direction upstream side of the tilting position of the pallet to scrape the pellets adhered to the pallet surface. 2. A pellet discharging device according to claim 1, further comprising a first pallet tilting means for tilting the pallet upstream of the scraping means in the pallet moving direction to discharge the loaded pellets downward. And a second pallet tilting means provided downstream of the scraping means in the pallet moving direction to discharge the pellets scraped off by the scraping means downward. 3. The pellet discharging device according to claim 1, wherein the scraping means inclines the downstream ends of the plurality of scraping plates in the pallet movement direction so as to face the center of the pallet in the width direction. An apparatus for discharging pellets, wherein the apparatus is arranged and arranged. 4. A pellet discharging device for drying or reducing pellets obtained by granulating a mixed powder of an iron raw material and a reducing agent on a hearth moving in a high-temperature atmosphere, and taking out the pellets to form a ring-shaped rotatable unit. A rotary hearth supported on the surface and the pellets are supplied to the surface, and a discharge screw disposed laterally at a predetermined rotation position of the rotary hearth and discharging the mounted pellets to the side. A pellet means, comprising: supporting means for rotatably supporting the discharge screw and movably in the vertical direction; and urging means for urging the discharge screw upward to reduce its own weight. Discharge device. 5. A discharging device for a pellet according to claim 4, wherein said detecting means detects an upward movement of said discharge screw, and an alarm means for issuing an alarm when said detecting means detects an upward movement of said discharging screw. An apparatus for discharging pellets, comprising: