JP5082556B2 - Raw material cutting feeder control method and apparatus - Google Patents

Description

  The present invention relates to raw material processing of a blast furnace, and in particular, in the conveying path from the raw material bunker to the raw material cut out, sieved with a screen, through a weighing hopper to the furnace charging conveyor, the amount of raw material such as coke and iron ore The present invention relates to a control method and apparatus for a raw material cutting feeder that stably cuts a raw material without being affected by moisture.

  As an example, iron ore and coke, which are one of the raw materials charged into the blast furnace, are cut out from a predetermined stocker by a target raw material amount while weighing the raw material cut out by a load cell attached to a weighing hopper. .

  These raw material dispensing techniques are disclosed in Patent Document 1. This open technology is a technology aimed at improving raw material dispensing speed control or improving the raw material dispensing start / stop timing control system. And the raw material discharge characteristic of the discharge gate are obtained in advance as the raw material discharge correction characteristic, and when the raw material discharge characteristic changes, the opening control characteristic of the discharge gate is corrected according to the raw material discharge correction characteristic.

  In the raw material payout characteristic calculation, the raw material payout characteristic is obtained according to the actual raw material payout result. These payout gate opening correction value calculation and raw material payout characteristic calculation enable the setting of the payout gate opening in accordance with the results by using the result collection data.

Further, Patent Document 2 discloses a technique for further improving the accuracy of the amount of a raw material finally cut out without increasing various data management and weighing in a relatively short time. . In this technology, the cutting speed of the raw material is within the allowable range of the cutting speed of the electric system and the mechanical system that controls the raw material, and is within the stable control range of the control system of the cutting speed control. The control function of quantity and cutting speed is realized. Further, the target cutting speed is obtained from the actual cutting remaining amount, and thereafter, the closed loop control is performed so that the actual cutting speed becomes the target cutting speed, and the actual cutting speed is continuously controlled to improve the weighing accuracy. This is a technique for shortening the weighing time.
JP-A-4-272110 JP-A-6-158125

  In the storage tank in the case of a blast furnace, a cutting feeder and a screen facility are generally installed. FIG. 4 is a diagram showing an example of equipment targeted by the present invention. In the figure, 1 is a raw material stocker, 2 is a raw material cutting feeder, 3 is a raw material cutting feeder drive controller, 4 is a drive motor, 5 is a screen, 6 is a belt conveyor, and 7 is coke. Each weighing hopper is shown.

  The raw material stored in the raw material stocker 1 is cut out by the raw material cutting feeder 2, sieved by the screen 5, and raw materials of a certain particle size or more are temporarily stored in the coke weighing hopper 7 after passing through the belt conveyor 6. (Not shown).

  The particle size of the raw material powder to be screened is determined by the screen size of the screen 5, and the speed of the feeder 2 is determined in consideration of the cutting time (equipment time cycle) and the screen efficiency of the screen 5, and the determined feeder 2 In general, the drive motor 4 is controlled by the raw material cutting feeder drive controller 3 so as to achieve a speed.

  However, if the moisture content of coke changes and increases due to weather conditions such as heavy rain, the coke powder content is reduced in the cutting mechanism system even if the speed of the cutting feeder 2 and the sieving screen speed are the same. This unsieved coke powder is charged into the furnace by a charging conveyor.

  FIG. 2 is a graph plotting the relationship between the coke moisture ratio and the coke powder rate. In the figure, the groups are divided into two groups, the group A data shows normal operation data, and the group B data shows the case where the coke moisture ratio increases due to heavy rain. When the water content of coke increases as in the case of Group B, powder adheres to the screen 5 due to water and the screen efficiency decreases, and the coke powder rate (weight of sieved powder / total weight of coke brought in) Go down.

  And the coke which was not sieved well and the ratio of the powder increased will be brought into the blast furnace. There was a problem in the operation of the blast furnace that the coke powder brought into the furnace greatly deteriorated the air permeability of the blast furnace and the liquid permeability of the hearth. The problems and solutions due to the fluctuation of the coke moisture ratio are not disclosed in the aforementioned Patent Documents 1 and 2.

  In view of the problems of these prior arts, the present invention provides a control method and apparatus for a raw material cutting feeder that stably cuts a raw material without affecting the amount of raw material powder such as iron ore and coke. Is an issue.

The invention according to claim 1 of the present invention is such that, in the control method of the raw material feeder using iron ore or coke as a raw material, the sieving efficiency of the raw material powder does not decrease based on the raw material moisture value stored in the raw material weighing hopper. The raw material cutting feeder control method is characterized by maintaining the raw material powder sieving efficiency by controlling the raw material cutting feeder speed.

The invention according to claim 2 of the present invention includes a raw material moisture meter for detecting raw material moisture provided in a raw material weighing hopper and a raw material weighing meter in a control device for a raw material cutting feeder using iron ore or coke as a raw material. A weighing detector that outputs a moisture value and a weighing value;
A control arithmetic unit for outputting a speed command value of the raw material cutting feeder based on the raw material moisture value and the weighing value from the weighing detector;
A raw material cutting feeder drive controller for controlling a drive motor of the raw material cutting feeder based on the raw material cutting feeder speed command value;
It is the control apparatus of the raw material cutting feeder characterized by providing.

  Since the present invention maintains the sieving efficiency of the raw material powder by controlling the raw material cutting feeder speed based on the raw material moisture value, even if the raw material moisture such as iron ore and coke rises, It is sieved off and it is possible to prevent excess raw material powder from being charged into the furnace. As a result, it was possible to solve the problem in the operation of the blast furnace, which was caused when the raw material moisture rose, that the air permeability of the blast furnace and the liquid permeability of the hearth deteriorated.

  In the present invention, when the raw material powder such as iron ore and coke is wet, if the speed of the raw material cutting feeder provided below the stocker is decreased according to the raw material moisture content, the screen sieving effect is exhibited, and the raw material powder It was invented with the knowledge that the minutes were sieved.

  FIG. 1 is a system diagram for explaining an embodiment of a control method and apparatus for a raw material cutting feeder according to the present invention using coke as an example of the raw material. In the figure, 1 to 7 are the same as those in FIG. 1, 1 is a raw material stocker, 2 is a raw material cutting feeder provided below the raw material stocker 1, and 3 is a raw material cutting device incorporating control means such as a thyristor and INV. Feeder drive controller 4 is a drive motor.

  By adjusting the drive motor 4 according to a control command from the raw material cutting feeder drive controller 3, the speed of the raw material cutting feeder 2 is controlled.

  5 is a screen for sieving the coke from the coke raw material stocker 1, 6 is a belt conveyor for sieving the coke powder with the screen 5, and a coke having a constant particle size that has not been sieved is installed in the vicinity of a blast furnace (not shown). The coke weighing hopper 7 is transferred.

  Reference numeral 8 denotes a coke moisture meter that detects the moisture of coke installed in the coke weighing hopper 7, and a weighing detector that outputs a moisture value and a weighed value. For example, a neutron moisture meter, an infrared moisture meter, or the like may be used as the moisture meter. However, the present invention does not limit the method on the moisture meter side, and may be any device that can measure moisture appropriately. .

  Reference numeral 9 denotes a control arithmetic unit, which is composed of a PLC, a sequencer, and the like, which inputs a weighing value from the weighing detector 8 and outputs a speed command value of the raw material cutting feeder 2 to the raw material cutting feeder drive controller 3. Receiving the speed command value of the raw material cutting feeder 2, the raw material cutting feeder drive controller 3 adjusts the drive motor 4 to control the speed of the raw material cutting feeder 2.

  In the present invention, when the coke moisture is high due to the coke moisture of the coke weighing hopper 7 and the coke weighing value, the raw material cutting feeder 2 is slowed down so that the screen 5 is sufficiently sieved. This prevents excessive coke powder from being brought into the furnace.

  When the coke moisture rises, the control calculator 9 calculates the cutting speed set value VR of the raw material cutting feeder by the following equation (1), for example.

VR = a−bX (1)

Where a, b: constant X: average moisture value (%)
FIG. 3 is a diagram in which the case where the feeder speed is lowered is plotted in FIG. In the figure, the group C group is one in which the speed of the raw material cutting feeder 2 is lowered when the coke moisture ratio is large, and it can be seen that the coke powder ratio is increased. When the speed of the raw material cutting feeder 2 is decreased, the sieving efficiency is maintained, and the coke powder rate does not decrease as in the group indicated by C, and an effective coke particle size can be secured.

  Compared to Group B, which has a lot of moisture and no countermeasures, Group B has a low coke powder rate and a large amount of coke powder is brought into the furnace. It can be seen that the coke powder rate can be kept high and the amount of coke powder brought into the furnace can be reduced. As a result, it was possible to solve the problem in the operation of the blast furnace, which was caused when the coke moisture increased, that the air permeability of the blast furnace and the liquid permeability of the hearth deteriorated.

  Although the raw material in the case of a blast furnace was demonstrated with the example of coke as mentioned above, this invention is applicable widely also in the industrial field which handles other granular materials, such as an iron ore.

It is a systematic diagram explaining one Example of the control method and apparatus of the raw material cutting feeder which concerns on this invention. It is the figure which plotted the relationship between a coke moisture ratio and a coke powder rate. FIG. 3 is a diagram in which the case where the feeder speed is lowered is plotted in FIG. 2. It is a figure which shows the example of the installation which this invention makes object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw material stocker 2 Raw material cutting feeder 3 Raw material cutting feeder drive controller 4 Drive motor 5 Screen 6 Belt conveyor 7 Coke weighing hopper 8 Coke weighing detector 9 Control calculator

Claims (2)

In the control method of the raw material cutting feeder using iron ore or coke as a raw material
A raw material cutting feeder characterized by maintaining the raw material sieving efficiency by controlling the raw material cutting feeder speed so that the sieving efficiency of the raw material powder does not decrease based on the raw material moisture value stored in the raw material weighing hopper Control method. In the control device of the raw material cutting feeder made of iron ore or coke
A raw material moisture meter for detecting raw material moisture provided in a raw material weighing hopper and a raw material weighing meter, and a weighing detector for outputting a moisture value and a weighing value;
A control arithmetic unit for outputting a speed command value of the raw material cutting feeder based on the raw material moisture value and the weighing value from the weighing detector;
A raw material cutting feeder drive controller for controlling a drive motor of the raw material cutting feeder based on the raw material cutting feeder speed command value;
A raw material cutting feeder control device characterized by comprising:

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