JP5776568B2 - Raw material handling with continuous unloader - Google Patents

Description

  The present invention relates to a method for unloading raw materials in a hold with a continuous unloader, and more particularly, to a method for unloading iron-containing raw materials containing moisture with a continuous unloader.

  When unloading iron-making raw materials such as iron ore and coal from a ship's hold that touches the quay, a continuous unloader is used to land the steel-making raw materials efficiently in a short time. The continuous unloader has a boom that can be swung and raised and lowered, and a bucket conveyor in which a plurality of buckets are mounted at a predetermined interval on an endless chain arranged in the vertical direction is attached to the tip of the boom. When handling steelmaking raw materials with a continuous unloader, the lower part of the bucket conveyor (scraping part) is inserted into the hold, and the bucket conveyor is operated to scrape the steelmaking raw material in the hold continuously with the bucket. Transfer to conveyor.

  However, since iron-making raw materials generally contain moisture, they have adhesiveness. Therefore, there is a problem that the steelmaking raw material adheres to the bucket, the bucket volume is reduced, and the cargo handling efficiency is lowered. There is also a problem that the weight on the bucket conveyor side becomes heavier than the weight on the counterweight side, the horizontal balance of the boom is lost, and the hoisting cylinder for hoisting the boom is overloaded.

Therefore, in Patent Document 1, a water pipe is provided on the bucket lowering side at the lower end of the bucket elevator (bucket conveyor), and a nozzle for injecting water toward the path of the bucket that is lowered during the idle operation of the bucket elevator is provided in the water pipe. Is disclosed.
Patent Document 2 discloses an invention in which a bucket cleaning tank capable of accommodating a scraping portion of a continuous unloader is provided on a pier, and a water discharge tool for discharging water toward the bucket is installed on an inner peripheral portion of the bucket cleaning tank. ing.

JP 2002-154634 A JP 2002-193429 A

In both of the inventions described in Patent Literature 1 and Patent Literature 2, bucket cleaning means is provided in the continuous unloader, and the material discharged to the bucket is removed to remove the material adhering to the bucket. It prevents the load.
However, since iron-making materials generally contain a lot of moisture, not only the problem of material adhering to the bucket, but also the iron-making materials slip on the material conveyance line after the continuous unloader, especially in the uphill part of belt conveyors and drop chutes. Then there is a problem of falling. Therefore, the conveyance speed of the raw material conveyance line has to be reduced, resulting in a decrease in cargo handling efficiency. Therefore, in the handling work of the iron-making raw material containing a lot of moisture, the handling efficiency (loading ability) over the entire material conveying line from scraping of the raw material in the cargo hold to loading of the iron-making raw material into the raw material yard becomes important.

  The ironmaking raw material to be landed is stacked in the raw material yard through an individual transfer device such as a continuous unloader, one or a plurality of belt conveyors, and a stacker constituting a raw material transfer line. The cargo handling efficiency in this series of operations is determined by being constrained by the transfer device having the lowest transfer capability (for example, transfer tonnage per unit time) among the transfer devices. In the case of an iron-making raw material having a high moisture content, slipping of the iron-making raw material on the belt conveyor may cause the cargo handling efficiency over the entire material conveying line to be limited by the conveying ability of the belt conveyor.

The present invention has been made in view of such circumstances, and in the handling work of iron-making raw materials containing moisture, the slip of the iron-making raw material in the raw material transfer line is prevented, and thus the handling efficiency over the entire raw material transfer line is improved. An object of the present invention is to provide a raw material handling method using a continuous unloader.
In the present specification, the “iron raw material” may be simply referred to as “raw material”.

In order to achieve the above object, the present invention provides a material handling method of scraping a steelmaking raw material in a hold with a bucket of a continuous unloader and transferring it to the outside of the ship.
A first step of scraping the surface portion of the loaded iron making raw material with the bucket to form a recess in the surface of the iron making raw material, and temporarily suspending the cargo handling operation of the iron making raw material, and moisture leaching from the iron making raw material A second step of collecting water in the concave portion, a third step of scooping out the water stored in the concave portion with the bucket and releasing it to the outside of the ship, and resuming the cargo handling operation of the iron making raw material, and releasing the moisture. And a fourth step of scraping the container with the bucket and transferring it to the outside of the ship.

  In the present invention, when the steelmaking raw material is landed using a continuous unloader, the ironmaking raw material and the water are separated in the hold so as not to transfer the steelmaking raw material containing moisture to the raw material conveyance line downstream from the continuous unloader. Then, only moisture is discharged out of the system. Specifically, the steelmaking raw material and the water can be separated by forming a concave portion that serves as a reservoir for the water contained in the ironmaking raw material on the surface of the loaded iron making raw material. Thereby, it becomes possible to easily remove moisture from the iron-making raw material.

Further, in the present invention , there is no need to newly provide a drainage facility for discharging the water stored in the recess to the outside of the ship, and the continuous unloader is used from the formation of the recess to the discharge of the water stored in the recess to the ship. be able to.

In the material handling method using the continuous unloader according to the present invention, water contained in the iron-making material can be efficiently separated and removed. That is, a concave portion is formed on the surface of the raw material with a bucket, the water accumulated in the concave portion is discharged to the outside of the ship, and then the iron-making raw material from which moisture has been released is scraped with the bucket and transferred to the outside of the ship. The steelmaking raw material does not slip. Therefore, it is not necessary to reduce the conveying speed of the iron-making raw material, and the cargo handling efficiency over the entire raw material conveying line can be improved.
Further, if the water stored in the concave portion is scooped up with a bucket and discharged to the outside of the ship, it is not necessary to newly provide a drainage facility, and the steel handling raw material can be efficiently handled.

It is a schematic diagram of a general continuous unloader. FIG. 3 is a layout diagram of a raw material conveyance line laid from a continuous unloader to a raw material yard. It is a schematic diagram for demonstrating the procedure of the raw material handling method by the continuous unloader which concerns on one embodiment of this invention, (A) is the state which has formed the recessed part in the raw material surface, (B) is a recessed part. A state where water is accumulated, (C) shows a state where water in the recess is being scooped up. It is a time history graph which shows the fluctuation | variation of the cargo handling efficiency from a cargo handling start to completion. It is a bar graph of average cargo handling efficiency from the start of cargo handling to completion.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.

An example of the continuous unloader 10 is shown in FIG. Moreover, an example of the raw material conveyance line (belt conveyors 31, 32, 33) laid from the continuous unloader 10 to the raw material yard 36 is shown in FIG.
The continuous unloader 10 is movable on the wharf 41 along the quay 40 where the ship 42 comes into contact with the berth, and the raw material S in the hold 43 is received by the bucket conveyor 15 attached to the tip of the boom 21 that can turn and undulate. It is a harbor facility that scrapes off and transfers it to a belt conveyor 31 installed outside the ship.

  The raw material S (iron-making raw material) generally contains a large amount of water W, and on average contains about 7 to 14% by mass of water W. Since the water W in the raw material S is unevenly distributed due to the influence of gravity, the particle size distribution of the raw material S, and the like, when viewed locally, there are many raw materials S containing the water W higher than the average value.

  The continuous unloader 10 includes a traveling frame 29 that can move on a pair of rails 34 laid along the quay 40, and a revolving frame that is pivotably installed on the traveling frame 29 and has a triangular shape when viewed from the side. 24 and a balancing beam 23 that undulates with the vertex of the swivel frame 24 as a fulcrum. Between the balancing beam 23 and the swivel frame 24, a hoisting cylinder 27 for hoisting the balancing beam 23 is provided.

A support link 25 that rotates in the vertical plane with the tip as a fulcrum is attached to the tip of the balancing beam 23 on the ship 42 side, and a bucket conveyor that extends in the vertical direction is attached to the tip of the support link 25. A bucket elevator 16 in which 15 is accommodated is attached. Further, a boom 21 including a boom conveyor 22 for conveying the raw material S is attached between the distal end portion of the support link 25 and an intermediate portion of the diagonal member 26 constituting the revolving frame 24. The support link 25, the diagonal member 26, the boom 21, and the balancing beam 23 constitute a parallel link. When the balancing beam 23 is raised and lowered, the bucket elevator 16 moves up and down while maintaining a vertical state.
On the other hand, a counterweight 28 is attached to the tip of the balancing beam 23 on the raw material yard 36 side so as to balance the weight on the bucket elevator 16 side.

  The bucket elevator 16 includes a cylindrical frame 11 fixed to the distal end portion of the support link 25, and a cylindrical column member 12 that extends downward from the cylindrical frame 11 and is rotatably supported by the cylindrical frame 11. I have. The bucket conveyor 15 has a pair of sprockets 17 disposed above the column member 12 and an endless chain 13 wound around a pair of sprockets 18 disposed below the column member 12 and the endless chain 13 spaced apart from each other by a predetermined interval. And a plurality of buckets 14 that are mounted. The lower part of the bucket conveyor 15 is L-shaped in a side view, and has a function of a scraping unit 19 that scrapes the raw material S.

The bucket 14 from which the raw material S has been scraped is conveyed upward and is reversed at the position of the pair of sprockets 17 disposed on the upper part of the column member 12. At that time, the raw material S in the bucket 14 is dropped onto the rotary feeder 20 disposed below the sprocket 17 and transferred to the boom conveyor 22 installed in the boom 21 via the rotary feeder 20. The raw material S conveyed to the swivel frame 24 by the boom conveyor 22 is dropped onto a belt conveyor 31 disposed immediately below the continuous unloader 10 through a hopper 30 installed in the swivel frame 24.
As shown in FIG. 2, the raw material S dropped on the belt conveyor 31 is transported to the raw material yard 36 by the belt conveyors 31, 32, and 33 disposed on the wharf 41 and stacked in a mountain shape by the stacker 37.

Next, a material handling method using a continuous unloader according to an embodiment of the present invention, that is, a method of landing a material S such as iron ore or coal containing a large amount of water W using the continuous unloader 10 will be described. .
(1) The surface portion of the raw material S loaded in the hold 43 is scraped by the bucket 14 of the bucket conveyor 15 to form a bowl-shaped concave portion 45 on the surface of the raw material S (see FIG. 3A). The scraped raw material S is transferred from the bucket conveyor 15 to the boom conveyor 22 via the rotary feeder 20.
(2) Since the water W oozes out from the raw material S into the recess 45, the leached water W is stored in the recess 45 (see FIG. 3B).

  The seepage of the water W into the recess 45 is frequently seen in iron ore when the raw material load (ton) in the hold 43 becomes 50% or less of the load capacity (ton) of the ship 42. If it becomes 40% or less, it will also be seen in coal. This is because the height distribution of the water W contained in the raw material S is affected by the balance between the gravity acting on the water W and the capillary phenomenon due to the surface tension, so that the raw material loading amount has decreased to the extent described above. Therefore, it is considered that the leaching of the water W easily occurs.

(3) The water W collected in the recess 45 is scooped up by the bucket 14 of the bucket conveyor 15 (see FIG. 3C). In order to prevent the scooped water W from being discharged onto the rotary feeder 20, the bucket conveyor 15 is stopped before the bucket 14 containing the scooped water W is reversed. Next, after the ship 42 side of the balancing beam 23 is turned upward to pull out the bucket conveyor 15 from the hold 43, the balancing beam 23 is turned to move the bucket conveyor 15 out of the ship. Then, the bucket conveyor 15 is operated in a direction opposite to the direction in which the raw material S is scraped, and the water W in the bucket 14 is discharged from the bucket 14 .
(4) After almost all of the water W accumulated in the recess 45 is discharged out of the ship, the scraping and transfer of the raw material S in the hold 43 by the bucket 14 is resumed.

Next, tests conducted to verify the effects of the present invention will be described.
The cargo handling work of the material in the hold was carried out by each method of the present invention (Example) and the conventional method (Comparative Example), and the fluctuation of the cargo handling efficiency (raw material transfer amount per unit time) from the start to the completion of the cargo handling was investigated. In FIG. 4, the time history change of each cargo handling efficiency of an Example and a comparative example is contrasted and shown. In addition, the comparative example implemented only bucket washing | cleaning, and the Example did not use bucket washing | cleaning together.

  In the comparative example, since bucket cleaning is performed, there is no reduction in bucket capacity. Therefore, high handling efficiency is maintained until 3 hours after the start of handling. However, as the cargo handling operation proceeds, the amount of water contained in the raw material increases. Therefore, after 4 hours from the start of cargo handling, the conveyor speed of the belt conveyor must be reduced to prevent the material from slipping. As a result, it took 32 hours from the start of cargo handling to completion.

  On the other hand, in the example, since bucket cleaning was not performed, the bucket capacity decreased, and when 1 hour passed from the start of cargo handling, the cargo handling efficiency gradually began to decline. For this reason, the cargo handling is temporarily stopped, a concave portion is formed on the surface of the raw material, and the moisture contained in the raw material is discharged out of the ship (a total of 2 hours between the 5th and 6th hours, and between the 11th and 12th hours). After that, the material handling work resumed. As a result, high cargo handling efficiency was maintained, and the cargo handling work was completed in 18 hours from the start of cargo handling. In addition, since a raw material will not adhere to a bucket any more if a certain amount of raw material adheres to a bucket, the influence which the reduction | decrease in bucket capacity has on cargo handling efficiency is limited.

  FIG. 5 shows, in a bar graph, the average cargo handling efficiency obtained by dividing the total amount of raw material transferred by the cargo handling time from the start to the completion of cargo handling for each of the example and the comparative example. From the figure, it can be seen that the average cargo handling efficiency of the example is 1.4 times or more larger than that of the comparative example. That is, it can be seen that the cargo handling efficiency is improved by implementing the present invention.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the configuration described in the above-described embodiment, and is within the scope of matters described in the claims. Other possible embodiments and modifications are also included. For example, in the above embodiment, bucket cleaning is not used together, but it goes without saying that it may be used together.

10: continuous unloader, 11: cylindrical frame, 12: column member, 13: endless chain, 14: bucket, 15: bucket conveyor, 16: bucket elevator, 17, 18: sprocket, 19: scraper, 20: Rotating feeder, 21: boom, 22: boom conveyor, 23: balancing beam, 24: turning frame, 25: support link, 26: diagonal material, 27: hoisting cylinder, 28: counterweight, 29: travel frame, 30: hopper , 31, 32, 33: belt conveyor (raw material conveyance line), 34: rail, 36: raw material yard, 37: stacker, 40: quay, 41: wharf, 42: ship, 43: hold, 45: recess, S: Raw material (steel making raw material), W: Water (moisture)

Claims (1)

In the material handling method of scraping the steelmaking raw material in the hold with the bucket of the continuous unloader and transferring it to the outside of the ship,
A first step of scraping the surface portion of the loaded iron making raw material with the bucket to form a recess in the surface of the iron making raw material, and temporarily suspending the cargo handling operation of the iron making raw material, and moisture leaching from the iron making raw material A second step of collecting water in the concave portion, a third step of scooping out the water stored in the concave portion with the bucket and releasing it to the outside of the ship, and resuming the cargo handling operation of the iron making raw material, and releasing the moisture. And a fourth step of scraping the material with the bucket and transferring it to the outside of the ship. A material unloading method using a continuous unloader.

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