JPS62227047A - Transferring method for sintered ore - Google Patents

Abstract

PURPOSE:To improve the stacked state of sintered ore so as to obtain superior cooling efficiency, by making the landing direction of sintered ore onto the conveyor of a cooling device face the traveling direction of the conveyor at the time of transferring sintered ore from a sintering machine to the cooling device. CONSTITUTION:The sintered ore 4 fallen from the ore discharge side of a Dwight-Loyd sintering machine 2 is crushed by a primary crusher 8 on a chute 5, which is al;lowed to land on the belt conveyor 7 of the cooling device 6 with changing its falling direction from direction D to direction E by means of a baffleplate 15. As a result, the sintered ore 4 lands in the direction E mutually opposite to the traveling direction B of the belt conveyor 7, so that large- diameter ores 10 are stacked on the lower layer side and small-diameter ores 11 on the upper layer side. In this way, by cooling the sintered ore 4 by means of a cooling gas passing through the belt conveyor 7 from the lower part to the upper part, heat exchange efficiency is improved and cooling efficiency is improved as well.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for transferring sintered ore, and specifically, a method for transferring sintered ore from a sintering machine to a conveyor of a belt conveyor type cooling device. When loading sintered ore onto a conveyor, the loading of sintered ore is related to a method of transferring sintered ore carried out to improve the situation and improve the cooling effect.

[Prior Art] The transfer characteristics of powder and granules largely depend on the particle size and shape of the powder and granules. For example, when the powder and granules are flown down along an inclined surface, the transfer characteristics of the powder and granules are particularly dependent on the particle size and shape. It is known that when the particles are a mixture of different sizes, the particles of different sizes aggregate and are stacked unevenly as a whole.

FIG. 2 is a schematic explanatory diagram showing the main parts of a conventional sintered ore production facility 1. As shown in FIG. The sintered ore 4 fired in the Dwight Lloyd type sintering machine 2 (hereinafter simply referred to as the sintering machine) is conveyed 8 in the direction of arrow A by the belt conveyor 3 of the sintering machine 2, reaches the ore discharge side, and is thrown into the chute 5. be done. The sintered ore 4 introduced into the chute 5 is passed through a primary crusher 8 installed in the middle of the chute 5.
(a crusher), and then falls along a chute 5 and is transferred onto a heat-resistant conveyor 7 of a belt conveyor type cooling device 6 (hereinafter simply referred to as a cooling device). The sintered ore 4 transferred onto the conveyor 7 is transported in the conveyor traveling direction (
It is cooled by cooling gas (for example, air) that is fed through the conveyor 7 from below to above in the direction of arrow B), and then passes through a crusher (secondary) (not shown), a product screen, etc., and then is sent to the blast furnace. It becomes sintered ore for charging. On the other hand, the cooling gas after cooling the sintered ore 4 becomes high in temperature due to heat exchange and is discharged as shown by arrow C through the exhaust hood 9.

In the existing sinter production equipment 1 as shown in Fig. 2,
Generally, the direction of drop and transfer from the sintering machine 2 to the conveyor 7 (the direction of the arrow) and the direction of conveyor travel of the cooling device 6 (the direction of the arrow B) are the same direction (both are rightward in the figure). It has been found that adopting such a configuration causes the following problems. That is, the sintered ore that falls from the ore discharge side of the sintering machine 2 is roughly crushed by the crusher 8, and then falls on the chute S in the lower right direction, but the granular sintered ore generated by the crushing is There is considerable variation in size. However, small particles fall gently from the chute 5 onto the belt conveyor 7 and are stacked as they are at the point where they fall onto the belt conveyor 7, but large lumps fall forcefully from the chute 5 onto the belt conveyor 7. Furthermore, it shows a tendency to move on the belt conveyor 7 and roll further away (towards the right in the figure). As a result, on the belt conveyor 7, as shown in FIG. 3, an unevenly deposited state is formed in which the small-diameter ore 11 occupies the lower layer and the large-diameter ore 10 occupies the upper layer.

[Problems to be Solved by the Invention] As described above, the cooling system in the cooling device 6 is such that cooling gas is supplied from below the belt conveyor 7, and sintering i12. It is common practice to cool the sintered ore while a cooling gas passes upward through the bed. When sintered ore in an unevenly piled state as shown in Fig. 3 is cooled by such a cooling method, it will reach a high temperature because the specific surface area of the large-diameter ore 10 is small and the cooling gas has passed through the small-diameter ore. Due to this, the higher up the sintered ore layer, especially the large-diameter ore 10, is not effectively cooled and is discharged from the cooling device 6 while remaining at a high temperature. As mentioned above, the sintered ore 4 discharged from the cooling device 6 is then further conveyed toward the blast furnace by another belt conveyor (conveyor exclusively for conveyance), etc.; 4 is assumed to be transferred in a cooled state, and generally does not have a heat-resistant structure. Therefore, the dedicated conveyor is burnt out by the sintered ore 4 which remains at a high temperature, and a situation arises in which the operation is forced to be suspended for a long time for repair. As a way to avoid this situation, it is possible to make the above-mentioned transport conveyor a heat-resistant structure, but retrofitting the existing equipment to a heat-resistant structure is not only not a fundamental solution, but also requires a considerable amount of expense. There is a problem with bulk.

Therefore, it was recognized that the essential measure was to improve the cooling device 6 side, that is, to improve the cooling efficiency, and for example, using a leveler to suppress or equalize the thickness of the sintered ore layer was considered. . As a result, Inukai ore 1 is unevenly distributed in the upper part of the sedimentary layer.
It was hoped that shifting 0 to the lower layer side would eliminate the uneven deposition situation all at once, but it was found that this was hardly effective in practice.

The present invention has been made in view of the above-mentioned current situation, and its purpose is to:
It is an object of the present invention to provide a method for transferring sintered ore that is carried out in order to bring the stacked state of sintered ore into a state with good cooling efficiency.

[Means for Solving the Problems] The present invention provides a method for transferring sintered ore in an inclined direction from the ore discharge side of a Dwight Lloyd type sintering machine onto the conveyor of a belt conveyor type cooling device. The main feature is that the direction in which the cooling device lands on the conveyor and the direction in which the cooling device runs on the conveyor are opposite to each other.

[Operation] The present invention is configured as described above, but the important point is that the direction in which the sintered ore lands on the conveyor (falling and transferring direction) and the direction in which the cooling device runs on the conveyor are opposite to each other. This is intended to make large-diameter ore unevenly distributed in the lower layer, thereby effectively cooling large-diameter sintered ore.

The present inventors first conducted various studies on the occurrence of the uneven deposition phenomenon using FIG.

First, it is assumed that the sintered ore after crushing consists of two types of spherical particles, large diameter and small diameter. Since the uneven deposition phenomenon occurs during the process in which these sintered ores are transferred on the chute 5 and on the stationary particles on the conveyor 7, it is necessary to study the transfer status of large-diameter particles and small-diameter particles separately. .

First, expressing the 10 equations of motion on the large diameter is as follows (1)
, expressed as equation (2).

du/dt=g (cos ψ-μ sin φ): (on the flat chute 5) (1) u=V: (on the stationary particle layer) (2) where μ is the particle friction coefficient.

On the other hand, the small-diameter ore 11 is filled with the gap between the large-diameter ore 10 using the gravity outflow formula [
(3) below], descends at a relative velocity of v and r, and stops when it reaches the surface of the stationary particle layer.

V,, = a (De - ds)' (n = 2.
67) However, α: Constant De: Effective diameter of the gap between large-diameter ore 10 ds: Small particle diameter The above equation of motion shows that when the conventional technique shown in FIG. This confirms that the phenomenon occurs. That is, when the sintered ore 4 falls 8ai from the chute 5 onto the belt conveyor 7 of the cooling device 6, the small diameter ore 11 lands on the upstream side of the belt conveyor 7, and the large diameter i
10 lands further away, that is, on the downstream side. As a result, as shown in Figure 3, a phenomenon occurs in which the small-diameter ore is deposited in the lower layer and the large-diameter ore is deposited in the upper layer.

Therefore, the inventors of the present invention found that if the direction in which the sintered ore 4 lands on the belt conveyor 7 and the direction in which the cooling device 6 runs on the conveyor are opposite to each other, a favorable uneven deposition phenomenon as shown in FIG. 4 described later can be achieved. The present invention was completed based on the idea that an opposite uneven deposition phenomenon might be formed in which large-diameter ore 10 is present in the lower layer and small-diameter ore is present in the upper layer.

[Example] Fig. 1 is a schematic explanatory diagram showing the main parts of a sintered ore manufacturing equipment 1 configured to carry out the present invention, and the parts corresponding to the conventional technology shown in Fig. 2 are the same. Attach the reference sign.

The sintered ore manufacturing equipment 1 shown in FIG.
An arrow is drawn on the baffle plate 15, and the object is dropped onto the belt conveyor 7 and placed thereon while changing the direction in the E direction. In this process, the sintered ore 4 is transferred to the next crusher 8 as in the case of Fig. 2.
It is crushed and sent down 8 along the chute 5. In the middle of the chute 5, there is a conveyor 7 which directs the direction of transport of the sintered ore 4.
A baffle plate 15 is provided to change the running direction (B direction) to the opposite direction. By providing the baffle plate 15 in the middle of the chute 5, the sintered ore 4 collides with the baffle plate 15, and the sintered ore 4 lands in the direction of landing on the belt conveyor 7 (in the direction of arrow E) and in the conveyor running direction of the cooling device 6 ( The directions of arrow B) may be opposite directions.

Considering the above-mentioned equation of motion, the large diameter ore 10 falls faster and is blown farther than the small diameter ore 11, so in adopting the configuration shown in Fig. 1, 1: +
The ore 10 will land on the upstream side in the conveyor running direction, and the small diameter ore 11 will land on the downstream side in the conveyor running direction. As a result, as shown in FIG. 4, on the belt conveyor 7, the large diameter ore 10 is on the lower layer side and the small diameter ore 11 is on the upper layer side. By achieving such a state of loading the sintered ore 4, the low-temperature cooling gas supplied from below the belt conveyor 7 first effectively cools the large-diameter sintered ore 10, and then the temperature is raised. The small-diameter sintered ore 11 is brought into contact therewith and cooled. That is, since the heat exchange efficiency of the cooling gas is improved, the temperature of the exhaust gas from the duct 9 is also improved, which is advantageous when exhaust heat is recovered and used.

There are no particular restrictions on the means for forming the landing direction of the sintered ore 4 on the belt conveyor 7 and the running direction of the belt conveyor 7 of the cooling device 6 to be opposite to each other, such as a chute. 5 or a screen-like material through which only the small-diameter ore 11 passes can be installed in place of the baffle plate 15 to change only the landing direction of the dog-diameter ore 10. May be adopted.

Next, the present inventors conducted experiments aiming at the following objectives (1) to (3).

(1) The inclination angle θ (see FIG. 1) of the baffle plate 15 is varied and its optimum value and allowable range are investigated.

(2) The feeding speed of the belt conveyor 7 is kept constant, the ore discharge speed from the belt conveyor 3 is varied, and the degree of uneven accumulation is investigated.

(3) Using the same self-lining type as the chute 5 and baffle plate 15 as in the actual machine, it is confirmed whether the desired uneven deposition reversal effect can be obtained.

The conditions for conducting each experiment (1) and (2) are as follows.
Shown in the table. That is, the feed rate was kept constant at 1.0 m/min, and the inclination angle θ was 36'', 40', 45°, and 50°.
and when the inclination angle θ is kept constant at 36°, the ore discharge rate from the sintering machine 2 is 1.0.1.5.2.0, 3.
．． 0 (m/min).

Table 1 The number of repetitions is 2 times when the ore discharge speed is 3.0 m/min, and 3 times in each of the other cases. The respective results are shown in FIGS. 6 and 7. FIG. 6 is a graph showing the effect of the inclination angle θ on segregation, and FIG. 7 is a graph showing the effect of the amount of discharged ore on segregation.

The following considerations can be made from FIGS. 6 and 7. That is, (1) it could not be said that variations in the inclination angle θ had a large effect on the uneven deposition, and (2) an increase in the amount of discharged ore reduced the degree of uneven deposition. In other words, it is effective to reduce the amount of ore discharged in order to achieve a good uneven deposition condition as shown in Figure 4, but in actual operation, reducing the amount of ore discharged will lead to a reduction in production. Undesirable. However, the inclination angle θ
is preferably about 36° in consideration of the angle of repose ψ (see FIG. 5 above).

Next, the present inventors mixed sintered ore of each particle size as shown in Table 2 below at a predetermined ratio, and stacked it on the belt conveyor 3 of the sintering machine 2 (layer thickness 100 mm), which was equipped with a cyclo reducer. The belt conveyors 3 and 7 are driven by a motor, and the upper and lower layers of the sintered ore 4 transferred to the belt conveyor 7 on the side of the cooling device 6 are sampled, and the particle size distribution and bulk density are measured. As is clear from Table 2, Figure 8, sintered ore with larger grain sizes exists in the lower layer, and sintered ore with smaller grain sizes exists in the upper layer, resulting in the good uneven deposition shown in Figure 5 above. It is understood that the condition has been achieved. As a result, the sintered ore 4 in the cooling device 6
The cooling efficiency of the system was further improved, and the problems of the conventional system were solved all at once. Incidentally, when large-diameter ore with a grain size of 30 mmφ was cooled by the method of the present invention while stacked on the upper layer side, it was found that the temperature could be reduced by 40° C. compared to the conventional method.

FIG. 9 shows an example in which the chute 5 and the baffle plate 15 have a self-lining structure. That is, a wear-resistant material 17 is fixed to the corner of the stepped steel plate 16a for the chute 5, and to the lower end of the inclined steel plate 16b for the baffle plate 15, and the sintered ore is fed from the upper part of the chute at the start of operation. The sintered ore is held up to the position indicated by the broken line, and the held sintered ore itself is used as a falling slope, and the sintered ore to be fed later is transferred on the held sintered ore and falls onto the belt conveyor 7. It is something that forces you to do something. With such a chute system, wear of the steel plate is suppressed, and the chute 5 and baffle plate 15 can have a long life.

Moreover, FIGS. 10(a) and 10(b) show the cross-sectional shape of the chute 5, and the central parts 5a and 5b of the bottom of the chute are configured to have a medium height so that drifting of the sintered ore on the chute 5 can be prevented. The baffle plate 15 can be constructed in the same manner.

[Effects of the Invention] As described above, according to the present invention, by employing the above-described configuration, the stacked state of the sintered ore is made into a state with good cooling efficiency, thereby solving the conventional problems at once. It is something that

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram showing the main parts of a sintered ore manufacturing equipment 1 configured to carry out the method of the present invention, Fig. 2 is a schematic explanatory diagram showing the prior art, and Fig. 3 is a schematic explanatory diagram showing the main parts of sintered ore manufacturing equipment 1 configured to carry out the method of the present invention. FIG. 4 is a cross-sectional view showing a conventional uneven deposition state, FIG. 4 is a cross-sectional view showing a good uneven deposition state formed according to the method of the present invention, FIG. 5 is a diagram assuming an uneven deposition phenomenon, and FIG. 6 is an inclination angle θ Figure 7 is a graph showing the influence of discharged ore on uneven deposition. Figure 8 is a graph showing the relationship between the average particle diameter and bulk density of sintered ore. Figures 9 and 10 (a), (
b) is an explanatory cross-sectional view showing another example of a chute used in the present invention. 2...Sintering machine 3.7...Belt conveyor 4...Sintered ore 5...Chute 6...Cooling device

Claims (1)

[Claims] When sintered ore is transferred from the ore discharge side of the Dwight Lloyd type sintering machine to the conveyor of the belt conveyor type cooling device in an inclined direction, the landing direction of the sintered ore on the conveyor and the conveyor of the cooling device are determined. A method for transferring sintered ore characterized by forming the traveling directions to be opposite to each other.