JP2904643B2 - Inventory management method and device in storage tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for managing inventory in a storage tank.

[0002]

2. Description of the Related Art A sintering plant for producing sinter ore has a large number of ore tanks for temporarily storing ore, limestone and the like as raw materials. These ore tanks are prepared for different types of sintering raw materials with different properties, and when receiving or paying out ore, etc., in the ore tank, it is necessary to control not only the amount but also the accumulation state in the ore tank .

However, there is a problem that the ore or the like adheres to the inner wall of the ore tank and stays in a stationary state near the outlet of the ore tank due to the properties of the ore and the like. If the ore etc. newly charged to the ore tank are paid out first, ore that continues to remain in the tank and the ore newly charged may mix in the ore tank, There is also a problem that the quality of the sintering compound raw material is deteriorated. That is, FIG. 1 is a view showing the present invention to be described later.
When the ore or the like charged to 1 in the full tank position 13 is dispensed, if no special countermeasures are taken, the charged material accumulation shape is sequentially changed from 14 to 15, and the central portion becomes significantly concave. For this reason, the following measures have been conventionally taken so as not to cause such a problem in the ore storage tank.

(1) Installation of vibrator A vibrator is provided on the lower outer wall of the ore storage tank and is operated intermittently to vibrate to break ore and the like remaining in the ore storage tank.

(2) Attachment of ceramic to the inner surface of the ore tank Ceramic is attached to the inner peripheral surface of the lower part of the ore tank where ore or the like is likely to remain to prevent the ore or the like from adhering.

(3) Water injection into the ore storage tank A plurality of water injection pipes are provided in the inner circumferential direction of the ore storage tank, and residual ore and the like are broken by injecting water from the water injection pipe.

[0007]

However, the above prior art has the following problems. In other words, in the method of operating the vibrator intermittently to break down the residual ore, etc., vibration is applied to the ore storage tank itself, so that there is a problem that cracks are generated by the vibration on the peripheral wall of the ore storage tank, and in addition, the vibrator is operated intermittently. Even if it is operated, vibration may be applied to unnecessary times, such as when the storage tank is full, which is wasteful.

In the method of attaching ceramic to the inner peripheral surface of the lower part of the ore storage tank, there are some methods which are ineffective due to the characteristics of the brand, such as the water content and the particle size of the ore and the like. Ore and the like are likely to remain in the pit, and the time and cost required for maintenance are large.

[0009] Further, in the case of a method in which residual ore or the like is broken by pouring water into the ore storage tank, not only a large amount of water is required, but also the water content of the ore and the like is changed, and the compounding for sintering is changed. It is difficult to control the water content of raw materials.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to advantageously solve the problems of the prior art, and
The inventory level of ore and the like in the ore tank is measured from above the ore tank at the central part and the side wall part of the ore tank, and the difference between the measured values is obtained. A method for managing inventory in an ore storage tank, characterized in that compressed air is blown out from the side wall of the ore storage tank into the ore storage tank to break down the ore or the like that is concavely deposited in the ore storage tank. It is.

Also, an ultrasonic level meter installed downwardly above the central part and the side wall part of the ore storage tank, and an air jet nozzle is looked up into the ore storage tank, and a vertical step is formed on the outer wall of the ore storage tank. A plurality of compressed air reservoirs arranged in a shape, a level measurement value obtained by an ultrasonic level meter disposed above the central portion and the side wall portion and a difference between the values and a predetermined reference value, and A control device having a function of judging a timing at which compressed air is ejected from the air ejection nozzle and selecting a compressed air storage to be activated and issuing an operation command of compressed air ejection. Is an inventory management device.

[0012]

According to the present invention, an ultrasonic level meter or the like is provided above the ore storage tank to measure the amount of ore and the like in the ore storage tank at two locations in the radial direction near the center and the side wall of the ore storage tank. Then, by determining the difference between the measured values, the shape of the ore or the like deposited in the storage tank is determined. In particular, when dispensing ore and the like from the ore storage tank, since the central portion is concave and concave, the degree of the concave is known from the difference between the measured values, and the value of the concave is larger than a predetermined reference value. Sometimes this is resolved. For this purpose, compressed air is injected into the tank from the compressed air storage provided in steps on the outer wall of the ore tank to break down the ore etc. on the inner wall of the ore tank and eliminate the depression at the center of the ore tank .

An ultrasonic level meter according to the apparatus of the present invention comprises:
For example, the one disclosed in Japanese Patent Publication No. 52-7735 can be used. It is effective to provide ultrasonic level meters above the side wall of the ore storage tank at a plurality of locations in the circumferential direction of the ore storage tank. At this time, it is desirable to provide the compressed air storage at a plurality of locations as well. The ultrasonic level meter is located at the center of the ore storage tank at a radius of 10
%, And in the side wall portion, it is desirable to set a point separated by 3/4 of the radius from the center point of the ore tank as a reference, and to be within ± 10% of the radius from that point.

Further, in the apparatus of the present invention, the reason why the nozzle for jetting compressed air is provided via the compressed air reservoir is that if a large amount of air is jetted at a time if the nozzle is directly provided in the air supply pipe, the air is not discharged. This is because replenishment cannot keep up and the pressure drop becomes significant. As means for preventing pressure drop in such a case, a pressure reducing valve is provided near each nozzle,
Up to that point, air can be supplied at high pressure. However, it is more preferable to use a compressed air storage device because there are legal regulations on high-pressure gas and maintenance of a pressure reducing valve.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a schematic view illustrating the present invention.
Ultrasonic level meters 1 and 2 were provided above a sintering raw material storage tank 11 having a diameter of 8 m at the upper part. The ultrasonic level meter 1 was provided at the center of the ore storage tank 11 in the radial direction, and the level meter 2 was provided at a position closer to the center by 1 m from the side wall of the ore storage tank 11 so as to face downward.

The left and right side walls of the storage tank 11 have a capacity of 130 l.
(Air blaster) is provided in a stepped manner, and reference numerals 3, 5, and 7 are provided on the left side and reference numerals 4, 6, and 8 are provided on the right side in three stages. Each air blaster 3
-8 are supplied with compressed air from the compressor 10.

Numeral 12 denotes a control device, which is an ultrasonic level meter 1, 2
Has a function of performing an operation based on the level measurement result of the above, and issuing an operation command of compressed air ejection to necessary portions of the air blasters 3 to 8. Each of the air blasters 3 to 8 has an obliquely downward air ejection nozzle 3A to 8A in the ore storage tank 11, and the air blaster receiving the operation command ejects compressed air from the air ejection nozzle. The ore that adheres to the inner periphery of the storage tank and breaks down remains. 9 is an air pipe in the figure.

The control device 12 according to the present invention performs the following calculations. (1) The value (ab) of the difference c between the measured values a and b measured by the ultrasonic level meters 1 and 2 is calculated. (2) The difference c is compared with a predetermined reference value d, and it is determined whether the difference c is equal to or larger than the reference value d. (3) Compare whether the measured value b is larger or smaller than the distance to the installation position of each of the air blasters 3 to 8. (4) An air blaster to be operated according to the above (1) to (3) is selected. The control device is provided with a sequencer to control the operation sequence of the air blaster.

FIG. 2 is a sectional view showing an embodiment of the present invention, and shows the shape of ore accumulation in an ore tank over time. An ultrasonic level meter 1 is provided at the center of the ore tank having an upper diameter of 8 m and a height of about 11 m, and an ultrasonic level meter 2 is provided at a position closer to the center by 1 m from the left side wall. Was. The air blasters 3 and 4 are 4.
The air blasters 5 and 6 are similarly placed 6.5 m below the upper end face on the side wall 5 m lower, and the air blasters 7 and 8 are 9
The present invention was implemented based on the level measurement values obtained by the ultrasonic level meters 1 and 2 installed at m lower levels, respectively. The results are shown over time from FIG. The reference value d at this time was 3 m.

In FIG. 2, the ore accumulation shape when the tank is full is shown as 21.
In addition, the accumulation shape before the air blaster was operated is indicated by 22 (A to D), the air blaster operation is indicated by 23 (A to D), and the time at that time is indicated by a numeral.

In FIG. 2 (a), the ore, which had been deposited in a convex shape when the tank was full (21A), became concave as the ore was discharged from the lower part (22A). At 9:56, the ore was measured by an ultrasonic level meter. The difference c between the values a and b has reached 3 m. For this reason, the air blasters 3, 4, 5, and 6 were operated to eject compressed air. As a result, at 10:01, the depression at the center decreased by about 1.5 m as shown by the curve of 23A.

At 10:45 pm, as shown in FIG. 2 (b), a noticeable depression appeared at the center (22 B), and the difference c also exceeded 3 m. So air blaster 3,4,5,6
At 10:48, three minutes later, the depression at the center decreased by about 1.5 m (23B). 11: 6
Since a remarkable depression appeared at the center in the minute (22C), the air blasters 3, 4, 5, and 6 were operated to improve the depression (23C). Further, at 12:38, a depression appeared in the center (22D), and the difference c exceeded 3 m.
Then, the air blasters 5, 6, 7, and 8 were actuated to eliminate the depression (23D). At this time, the value measured by the ultrasonic level meter 2 was lower than the positions of the air blasters 3 and 4, so the air blaster was used. 3, 4 were not activated.

As described above, according to the present invention, the ore accumulation shape in the ore storage tank is grasped, and when a significant depression is generated in the center, the air blaster is operated to break the ore on the inner wall of the ore storage tank. It was confirmed that it was possible to solve the problem by filling the depression.

[0024]

As described above, according to the present invention, when the ore and the like in the ore tank are discharged from the lower part of the ore tank, the ore and the like are deposited on the inner wall of the ore tank, particularly on the lower inner peripheral wall. It is possible to eliminate the phenomenon of sticking and accumulating and causing a significant depression in the center, preventing a decrease in the supply capacity of ore and the like, and solving the problem of mixing different types of ores in the storage tank.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating the present invention.

FIGS. 2A to 2D are cross-sectional views showing a charge accumulation shape according to an embodiment of the present invention.

[Explanation of symbols]

 1, 2 Ultrasonic level meter 3-8 Compressed air storage unit 3A-8A Air ejection nozzle 10 Compressor 11 Mineral tank 12 Controller

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinichi Matsunaga 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Corporation Kimitsu Works (72) Inventor Masahiro Saito 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Kimitsu Works, Ltd. (56) References JP-A-57-189931 (JP, A) JP-A-59-49695 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B65G 65/30-65/48 G01F 23/28

Claims (2)

(57) [Claims] 1. An inventory level of ore and the like in an ore tank from above the ore tank is measured at a central portion and a side wall portion of the ore tank, and a difference between the measured values is obtained. Ore characterized by breaking compressed ore etc. in the ore storage tank by blowing compressed air from the side wall of the ore storage tank into the ore storage tank when the value exceeds the reference value Inventory management method in the tank. 2. An ultrasonic level meter installed downward above the central part and the side wall part of the ore storage tank, and an air ejection nozzle is looked up into the ore storage tank, and is vertically attached to the outer wall of the ore storage tank. From a plurality of compressed air reservoirs installed in a stepped manner, and a level measurement value by an ultrasonic level meter installed above the central part and the side wall part and a difference between the values and a predetermined reference value,
A controller for judging a timing at which compressed air is ejected from the air ejection nozzle of the compressed air storage, selecting a compressed air storage to be operated, and issuing an operation command for compressed air ejection. Inventory control device in ore tank.