JP2007204179A - Powder level control method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder level control method and a device controlling a powder level in a second hopper on a downstream side to a constant level. <P>SOLUTION: A weighing set value, i.e., a discharge target amount predetermined relative to a first discharge device is corrected based on a correction amount calculated based on a value obtained by measuring the present storage amount of the second storage hopper by a second weighing means and a discharge actual measurement value measured by a first weighing means to determine a discharge set value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, the granular material discharged from the storage hopper is transported using a transportation means such as a conveyor, put into a different receiving hopper, put into the receiving hopper, and then downstream from the receiving hopper. The present invention relates to a method and an apparatus for controlling the level of powder in a powder supply facility for supplying powder to a facility.

  As a method of charging the granular material, which is a raw material, into a processing facility (such as a blast furnace) using the granular material (coal, coke, etc.) as a raw material in a conventional steel process, a first storage hopper (hereinafter referred to as a first hopper) The granular material cut out from the second hopper is transported by using a conveyor, is put into a second storage hopper on the downstream side (hereinafter referred to as a second hopper), and the granular material charged into the second hopper is Furthermore, the method of supplying to the downstream processing equipment is usually taken. At this time, a fixed amount (a constant weight) of the granular material is cut out by a first raw material discharge device (hereinafter referred to as a first discharge device) that cuts a fixed amount from the first hopper, and transported to the second hopper by a conveyor. It takes the form of supplying a granular material from the 2nd hopper to the processing facility of a downstream by the 2nd raw material discharge device (henceforth a 2nd discharge device).

  The level control of the granular material thrown into this 2nd hopper is performed by increasing / decreasing the amount of the granular material cut out by the 1st discharge device from the 1st hopper, or performing starting stop of a conveyor.

  However, the measured values of the first hopper weigher and the second hopper weigher are not exactly the same, and an error occurs between the two, so that the amount of storage in the second hopper exceeds the capacity. In some cases, the amount of storage in the second hopper may be smaller than the amount of buffer scheduled in advance as a backup for backup.

  In such a case, in order to prevent the second hopper from becoming full and overflowing the granular material, there is a method of keeping the level setting value of the second hopper low. However, this second hopper usually has a storage capacity for several charges of the amount of equipment input as a buffer function in case of failure of the first hopper. If the value is too low, the amount of powder in the second hopper becomes too small, and the buffer function cannot be used effectively, and it is not easy to set the level without excess or deficiency.

  Also, if the conveyor is stopped when the amount of powder in the second hopper has increased, the load on the drive unit when the conveyor is restarted increases because of the particles remaining on the conveyor. This requires a large capacity electric motor.

As a technique for solving the above problems, Patent Document 1 describes the sum of the amount of powder on the conveyor and the amount of powder in the second hopper as the amount of powder in the second hopper. In view of this, a technique is disclosed in which the weight of the granular material is kept constant by a system including the conveyor and the second hopper by controlling the amount cut out to the conveyor.
JP 2000-118718 A

  However, even the technique described in Patent Document 1 does not eliminate the point that the measured values of the weighing device of the first hopper and the weighing device of the second hopper do not exactly coincide with each other. Therefore, an error is accumulated in the calculated weight of the powder on the conveyor. For this reason, there is a problem that a fundamental solution of the problem that the storage amount of the second hopper that has conventionally occurred is not constant has been reached.

  This invention is made | formed in view of the said situation, and it aims at providing the level control method and apparatus of a granular material which controls the granular material level in the downstream 2nd hopper uniformly.

  In the invention according to claim 1 of the present invention, when the powder is discharged from the first storage hopper that temporarily stores the granular material, and is transported to the second storage hopper that temporarily stores the granular material, the first By determining a discharge set value to be discharged from one storage hopper based on a discharge actual measurement value of the first storage hopper and a value obtained by measuring a storage amount of the second storage hopper, the second storage hopper It is a level control method of a granular material characterized by controlling a granular material level.

  The invention according to claim 2 of the present invention includes a first storage hopper for temporarily storing powder particles, and a first weighing means for discharging the powder particles from the first storage hopper. 2nd in the granular material supply equipment provided with the discharge | emission apparatus, the transport means which conveys the discharged | emitted granular material, and the 2nd storage hopper which has a 2nd weighing | measuring means further temporarily stored in the downstream. A granular level control device for controlling a granular level of a storage hopper, wherein the level control device sets a discharge set value for the discharge device, a weighing set value that is a predetermined discharge target amount, and It is calculated | required based on the correction amount computed based on the value which measured the present storage amount of the 2nd storage hopper with the 2nd weighing means, and the discharge actual value measured by the 1st weighing means. It is a level control apparatus of a granular material.

  Note that the present invention is not limited to the combination of two hoppers, and even if it is a conveying device for powder particles from more than two hoppers, a set of two front and rear ("i + 1th (downstream side) Needless to say, it is possible to apply the information by feeding back the information of “hopper” to the “i-th (upstream hopper)” in a plurality of sets.

  In the present invention, the discharge target set value of the first discharge device is set to a correction amount calculated based on a value obtained by measuring a current storage amount in the second hopper, and an actual measurement value measured by the weighing device of the first hopper. Since the feedback is provided, the second hopper level can be controlled to be constant, and there is no trouble such as overflow from the second hopper or less than the planned buffer amount.

  The best mode for carrying out the present invention will be described below with reference to the drawings and equations. FIG. 1 is a diagram showing an outline of a granular material supply apparatus according to the present invention. In the figure, 1 is a first hopper, 2 is a second hopper, 3 is a first discharge device, 4 is a weighing device, 5 is a second discharge device, 6 is a level meter, 7 is a conveyor, and 8 is a level control device. Represent each.

  The powder (raw material such as coal and coke) is transferred onto the conveyor 7 by the first discharge device 3 equipped with a weighing device 4 capable of cutting out a predetermined weight from the first hopper 1 containing the powder. To be discharged. Then, it is conveyed to the second hopper 2 by the conveyor 7 and is put into the second hopper 2. Further, a predetermined amount of the granular material is cut out from the second hopper 2 and supplied to a processing facility (not shown, for example, a blast furnace).

  In this invention, it controls so that the granular material level stored in the 2nd hopper 2 may be kept constant, and the granular material cut out with the 1st discharge device 3 in the 1st hopper 1 which temporarily stores a granular material. It is for adjusting the amount of the body.

  In addition, the 2nd hopper 2 has a capacity | capacitance several times (for example, about 3 to 5 times) the quantity supplied to the processing equipment at once. Further, the amount of the granular material cut out from the first hopper 1 is about one-fifth the amount of the second hopper 2. Therefore, even when a failure such as discharge from the first hopper 1 or operation trouble of the conveyor 7 occurs, the supply amount of at least several times can be stored in the second hopper and supplied to the processing equipment. Therefore, it is possible to operate without stopping the entire equipment.

  Note that the cutout amount (discharge amount), cutout (discharge) timing, and the like of the powder particles in these two storage hoppers are controlled and adjusted by the hopper control device 8.

  FIG. 2 is a block diagram showing a signal processing flow in the level control apparatus according to the present invention. FIG. 3 is a flowchart showing a signal processing flow in the level control apparatus according to the present invention.

  First, a weighing set value SV0, which is a target set value of the amount to be cut out by the first discharging device, is given to the first hopper. This value is a predetermined amount based on the conveying capacity of the conveyor and the amount of one time supplied from the second hopper to the processing facility.

  In the present invention, the correction amount calculated based on the value obtained by measuring the current storage amount in the second hopper and the value of the actual measurement value measured by the first hopper weighing device are fed back to the weighing setting value. To determine the cutout amount to the first hopper and set the value in the cutout device.

Hereinafter, a correction method performed based on the current storage amount in the second hopper will be described.
First, in order to measure the storage amount (storage weight) of the second hopper, a level meter 6 set at the upper part of the second hopper is used. The level meter 6 is generally a distance sensor that can measure the surface position of the stored granular material, and a laser distance meter, for example, is sufficient. With this level meter, the height of the stored granular material (raw material) is calculated, and based on this height level, calibration data for converting a preset level into weight is used. 2 Calculated by converting to the weight in the hopper.

The storage amount W is compared with a predetermined storage target weight W ₀ set in advance, and the correction amount δ of the cut-out amount of the first hopper is determined by the deviation ΔW.

ΔW = W−W ₀ (1)
In addition, if the 2nd hopper has the measuring instrument which can be measured directly, you may measure the storage amount of a 2nd hopper.

The procedure of the correction amount calculation process is as follows.
Assuming that Wmax is the correction judgment weight upper limit value and Wmin is the correction judgment weight lower limit value, the storage amount of the second hopper is too large when the following expression (2) is satisfied.

ΔW> Wmax (2)
Alternatively, when the following expression (3) is satisfied, it is determined that the storage amount of the second hopper is too small.

ΔW <Wmin (3)
As described above, when the condition of the expression (2) or (3) is satisfied, it is determined that it is necessary to correct the cutout amount in the first hopper, and the deviation ΔW is added as the correction amount δ.
If the following expression (4) is satisfied, it is determined that the operation is normal, and the correction amount δ = 0 is output (that is, not corrected).

Wmin ≦ ΔW ≦ Wmax (4)
Note that the present invention is not limited to the combination of two hoppers, and even if it is a conveying device for a granular material from more than two hoppers, the upstream hopper is the first in the above description. By considering the hopper and the downstream hopper as the second hopper, in the facility equipped with N hoppers, the i + 1 hopper (which is counted as No. 1 and No. 2 from the upstream) is the second hopper at the downstream hopper. If the information is considered to be fed back to the first hopper of the i-th (upstream hopper), it can be applied by combining more than two hoppers in order and combining them sequentially. Needless to say. Moreover, you may apply to all the hoppers, and you may apply limiting to arbitrary hoppers.

When the correction value δ is obtained as described above, the set value SV1 is obtained from the weighing set value SV0 as shown in equation (5).
Set value SV1 = Weighing set value SV0-Correction amount δ (5)
Further, a weighing result PV is obtained from the weighing device of the first discharging device, and a weighing correction value ΔV is obtained as in equation (6).
Weighing correction value ΔV = Setting value SV1 – Actual weighing PV (6)
Then, the set value SV2 finally given to the first discharging device of the first hopper is obtained as in equation (7).
Set value SV2 = Set value SV1 – Weighing correction value ΔV (7)

It is a figure which shows the outline | summary of the granular material supply apparatus which this invention concerns. It is a block diagram which shows the signal processing flow in the level control apparatus which concerns on this invention. It is a flowchart which shows the signal processing flow in the level control apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st hopper 2 2nd hopper 3 1st discharge device 4 Weighing device 5 2nd discharge device 6 Level meter 7 Conveyor 8 Level control device

Claims (2)

When discharging from the first storage hopper for temporarily storing the powder, and transporting the powder to the second storage hopper for temporary storage,
The second storage is determined by determining a discharge set value to be discharged from the first storage hopper based on a measured discharge value of the first storage hopper and a value obtained by measuring a storage amount of the second storage hopper. A method for controlling the level of powder particles, comprising controlling the level of powder particles in a hopper. A first storage hopper for temporarily storing powder, a first discharge device having a first weighing means for discharging the powder from the first storage hopper, and transporting the discharged powder For controlling the granular material level of the second storage hopper in the granular material supply facility comprising a transporting means for transporting and a second storage hopper having a second weighing means for further temporary storage downstream thereof A body level control device,
The level controller is
The discharge setting value for the discharge device is
A weighing set value which is a predetermined discharge target amount;
A correction amount calculated based on a value obtained by measuring the current storage amount of the second storage hopper by the second weighing means;
A level control apparatus for a granular material, which is obtained based on an actual discharge value measured by a first weighing means.

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