JPS6270506A - Method for throwing charge into blast furnace - Google Patents

Abstract

PURPOSE:To throw charge in an intended distribution state into a blast furnace by determining the deviation between the actual opening speed and set opening speed of a bell positioned in the lowermost stage, calculating the correction opening speed therefrom and correcting the next set opening speed with said speed. CONSTITUTION:The opening time TSi and opening degree PSi of a large bell 2 for an optional number of batches are optionally set and are inputted to an input board 14 for setting and are stored into a furnace top sequence control device 12. The values (TSi, PSi) area successively drawn out in conformity with the batch progression of the furnace top sequence and are calculated and converted to the speed set value VSi of the large bell=PSi/TSi. On the other hand, the control device 12 determines the correction opening speed DELTAVi by the prescribed equation in conformity with the batch progression of the furnace top sequence and corrects the speed set value VSi of the large bell by using the same. The large bell 2 operate in accordance with the control set value (VSi+DELTAVi) and stops finally at the set open position PSi by receiving the limination by the collation and calculation with the pulse signal of a pulse transmitter 13.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for charging materials into a blast furnace, and particularly, the present invention relates to a method for charging materials into a blast furnace, and in particular, an interior of a blast furnace equipped with one or more bells at the top of the furnace for charging raw materials into the furnace. Concerning improvement of container loading method.

[Conventional technology]

Generally, the charging and distribution control of raw materials into a blast furnace varies depending on the raw material properties and the amount of raw materials charged. Therefore, in order to maintain appropriate and stable gas distribution and temperature distribution in the furnace, for example, if the gas flow toward the center of the furnace is strong, it is necessary to charge ore toward the center of the furnace, or to charge coke into the furnace. It is necessary to suppress the excessive gas flow in the center by charging the gas toward the wall side. Conventionally, this control has been achieved by adjusting the position of the so-called movable armor notch and the level of the stock line. If the layer thickness of coke or ore in the radial direction inside the furnace is appropriately controlled through this adjustment, it becomes possible to improve the blast furnace gas utilization rate and operate at a low fuel ratio. However, when controlling the burden distribution in a bell-type blast furnace, it is difficult to achieve an appropriate burden distribution by adjusting only the position of the movable armor knot and the level of the stock line, which are limited distribution adjustment elements. It was pointed out that it is not possible to make fine adjustments. In other words, in a bell-type blast furnace, the charged material is discharged all at once from the bell, so it is difficult to charge the material evenly in the radial direction of the furnace. Even when it is desired to charge ore only to the second side, all the raw materials are charged at the same position, which has the disadvantage that fine adjustment of the gas distribution is not possible. As a technique to eliminate this drawback, Japanese Patent Application Laid-Open No. 59-9108
, No. 59-9109, and No. 59-41403. This method controls the charging amount and charging position of raw materials by adjusting the bell opening degree or bell opening speed, solving the disadvantage of the bell that the material is charged at the same position at the same time, and This is intended to optimize the distribution of the charge in the radial direction, that is, the gas distribution. The difference between this method and the previous method will be explained with reference to FIG. Figure 3 shows the motion diagram of the large bell, where the horizontal axis is the time T.
(sec > , I-axis is the large bell opening P (lTlm). The driving source of the large bell is a hydraulic cylinder,
The opening and closing of the large bell is controlled by the opening and closing operation of the solenoid valve in this hydraulic circuit. In the previous method, the solenoid valve of this hydraulic circuit was simply fully opened or fully opened, so as shown in the solid line graph in Figure 3, the large bell was at full speed (fastest speed) - the large bell fully open position Pa This has the disadvantage that the raw materials that move up to the top end fall in the same place all at once. On the other hand, according to the improved conventional ff, +J tIh method,
As shown in the dotted line graph in Figure 3, the large bell is not opened to its entire position Pa, but is kept at an opening halfway, and the opening operation time (speed) is adjusted to slowly feed the raw material. The final bell opening time and opening degree (Ti, P+) in this method are determined by the various dotted lines in Figure 3 for each raw material seed pot or batch. As shown in FIG. 2, the variation rate is set so that the optimum raw material distribution in the furnace is obtained. In this case, each final bell opening time and opening degree are set so as to be in an almost inversely proportional relationship. This means that if the bell opening time is short, it is necessary to ensure a sufficient opening for the raw material to fall, and conversely, if the bell opening is small, the raw material must be allowed to fall within the range of that small opening. This is because it is necessary to ensure sufficient opening time for the large bell to discharge water.When adjusting the operating speed of the large bell using this improved conventional control method, the solenoid valve of the hydraulic circuit described above must be This is done by adjusting the oil whistle to the hydraulic cylinder by narrowing down the opening, that is, by adjusting the opening position of the solenoid valve. ■If the bell opening degree is small or the bell opening speed is slow, more material will accumulate on the furnace core side. ■If the bell opening degree is large or the bell opening speed is fast,
A large amount of raw material accumulates on the furnace wall side. can be mentioned. Therefore, it is attracting attention as an effective method for adjusting the gas distribution in the blast furnace at present.

Problem 1 to be Solved by the Invention However, when this control method is actually applied, the following problems are pointed out. Even if the opening degree of the hydraulic solenoid valve is set corresponding to Δ, the opening speed specified by the digit (for example, P i / T i in Fig. 3), the temperature, viscosity, turbidity, etc. of the oil in the hydraulic circuit The actual speed of the large bell may vary due to changes in the properties of the raw materials on the large bell (particle size, wheel end, scales, blending ratio), and changes in weight due to the discharge of Ill from above the bell. is not constant, and as shown by the two-dot chain line in Figure 3, it moves quickly and moves quickly (Ti=,
Pi) or act slowly (Ti, Pt
), causing slight fluctuations, making it impossible to strictly control the in-furnace intake/distribution f[i (B) The opening time and opening degree (Ti, Pi) mentioned above must be changed frequently. The machine is easy to operate, and the operating time is short (MAX 40se
c), we are in a bad situation where we have to control il+ instantly. Therefore, a relatively large-scale calculation is required, leading to an increase in cost. (Objective of the Invention 1) The present invention has been made to solve the above problems, and is aimed at preventing changes in the temperature, viscosity, turbidity, etc. of the oil in the hydraulic circuit, or changes in the properties of the raw F8+ on the large bell. The bell can be controlled to the intended opening degree at the intended time, regardless of the change in Ifli due to the discharge of raw material from above the bell, and as a result, the radial direction of the charge inside the furnace can be controlled. A method of charging a blast furnace that allows for free and accurate adjustment of the distribution of particles, does not require large scales for adjustment, and can sufficiently handle frequent setting changes or short-time control. It is an object of the present invention to provide a material charging control method. [Means for solving the problem] The present invention adjusts the opening speed of a bell located at the bottom stage behind the bell provided at the top of a blast furnace. In a blast furnace charging method in which the charging material is charged into the furnace while
The procedure for calculating the opening speed deviation from the previously set opening speed and the actual opening speed, the procedure for calculating the corrected opening speed based on this opening speed deviation, and the procedure for correcting the set opening speed by this corrected opening speed. The above object is achieved by including a procedure of setting this as the next set opening speed. (Effect 1 As mentioned above, there are many uncertain factors that affect the opening speed of the large bell, such as changes in the properties of the oil, changes in the properties of the raw material on the large bell, and changes in weight due to the discharge of raw material from the top of the bell. They exist and they interfere with each other.The reality is that it is extremely difficult to grasp these individually and systematically, and there is no effective way to do so. Even if it were possible to understand the constant FL, it would require an extremely complicated program to reflect all of them in the control, and under adverse conditions such as frequent setting changes and short operating time. This is almost impossible to achieve. Therefore, in the present invention, these elements are relatively constant over a short period of time (for example, the oil temperature at the current charging is different from the oil temperature at the previous charging. We focused on the fact that the speed deviations do not change much), grasped the pixels of these changes from past speed deviation records, and controlled by sequentially reflecting this in the latest bell operation, regardless of these changing factors. First, it is possible to perform highly accurate quantity control, and as a result, it is possible to charge the charge with an intended distribution. [Examples] Examples of the present invention will be described in detail below based on the drawings. Figure 2 schematically shows a cross section near the top of a blast furnace to which the method for charging materials into a furnace according to the present invention is applied. First, to explain this device, there is a The large bell 2 is positioned via the bell rod 3 and the segment 4,
The balance is adjusted by a counterweight 5,
It is driven by a hydraulic cylinder 6. The hydraulic cylinder 6 is driven up and down by pressure oil from the hydraulic unit 7 through the valve 8, and this is connected to the opening movement of the large bell 2. On the other hand, the raw material is temporarily deposited on the small bell 1 by the rotating chute 9, and then deposited on the large bell 2 while adjusting the equal discharge pressure by the two bells, the small bell 1 and the large bell 2. Thereafter, due to the opening operation of the large bell 2, it collides with the removable armor 10 or the armor plate 10A, adjusts the falling position in the radial direction, and falls to the raw material stock line.
). Now, in the previous method of charging raw materials, large bell 2 was
Opens at full speed to the fully open position by switching control of the solenoid valve 8,
In addition, after all the questions are detected, the control is closed again (returning to the O position). In this embodiment, the specified opening time TSi and opening degree Ps
The opening speed based on i ■ Since the large bell 2 is driven according to Si, the furnace inner radius 1 on the raw material stock line Δ
) It is possible to finely adjust the drop position and Φ in the direction. Specifically, this opening speed control is achieved by providing a flow control valve 11 whose opening degree is adjusted by a servo moke 16 in the oil line 15 that becomes the return side piping during the large bell operation, and
This is done by controlling the oil flow rate. In this embodiment, in order to give an appropriate opening command to the flow control valve 11, a large bell 2 is also provided.
A furnace top sequence control device 12 is installed which has full memory for opening speed correction control. This P-top sequence device 12 receives output signals from a pulse generator 13 provided on the rotating shaft 17 of the segment 40 in order to capture every movement of the large bell 2 during the opening operation, and a desired output signal. It is configured to receive an output signal from a large bell opening time/opening degree setting input panel 14 for setting the opening time TSi and opening degree Psi of the large bell 2. Next, from the large bell opening time/opening degree setting input panel 14, we will explain in detail the operation contents of the program memory function of the opening speed supplement TJ1 control of the large bell 2 of this embodiment device. The large bell opening time and opening degree (T
(Si, Psi) are set and input as desired. Thatlff1(
TSi, Psi) are all controlled by the top sequence controller Go2.
is captured and stored in memory. This stored value (TS
i, Psi) are drawn out sequentially as the batch progresses in the furnace top sequence to obtain the large bell speed set value VSi=PSi/T.
Calculated and converted to Sr. On the other hand, apart from this, the furnace top sequence control 7Il device 1
2, the following (1
) The corrected opening speed ΔVi is obtained by calculating the equation, and this is executed one by one. 8V'+ -K ΔV r-+ + (1-k)
8Vi−x−(1) Here, ΔV +−+ is the previous time (i
-1) large bell speed setting value V S r-+ and the actual resultant value V i-+ of control based thereon which is the difference value. Note that this actual result value V i-1 is determined by the pulse generator 13
pulse count (actual final large bell opening P i-+ based on ID and timer count value T that reached that position)
+−+Which result (P i−+ /T +−+ ) is obtained. Δv, -2 is the large bell speed setting value VSi-2 up to the previous time (i-2) and the actual resultant value of control based on it ■1-
This is the calculation result of the moving average value with the difference value from 2. k is a constant that adjusts the weight balance of either the previous actual VI difference value ΔV i-1 or the previous actual moving average difference value Δ■1-2. In this embodiment, k is set to a value close to 1 in order to preferentially reflect the previous performance ΔV i-+ in the next control as much as possible. Note that when k=1, the correction is based only on the previous performance. Next, the aforementioned large bell speed set value VS+ is corrected using the calculation result Δ■1 based on the above. That is, (VSi+△
Vi) is given to the flow control valve 11 as the control setting (direct) for this time (i).Flow control valve 1
1, the opening degree Sl! of the oil line 15 to the solenoid valve 8 is controlled by the servo motor 16 as position control proportional to the set value ff1lJl! 1 adjustment is made. The large bell 2 operates according to the control setting value (VS i + ΔVi), and finally stops at the setting amount position PS+ due to the collision with the pulse generator 13's valve swing g. Here, the reason why the stop is not limited to the set amount time TSi is because the operating speed is abnormally fast and the set amount position P
This is to avoid stopping before reaching Si and not being able to discharge the raw material sufficiently. In this embodiment, the above introduction method is used to perform optimal control while correcting subtle process changes over time. Effects of the Invention As explained above, according to the present invention, changes in processes that have a high degree of change over time, such as changes in properties such as oil temperature, viscosity, and turbidity, ff! due to changes in properties such as particle size, 4L type, blending ratio, etc., or due to discharge of raw materials from the top of the bell. It is now possible to control the opening degree and opening speed of the large bell with high precision regardless of changes in the load, and as a result, the charge can be directed in the radial direction inside the furnace.
An excellent effect can be obtained in that it becomes possible to feed the liquid in this distributed state. In addition, since the control system is relatively simple, it can be executed with a simple computer, and it can sufficiently cope with frequent setting changes or short-term control.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the gist of the method for charging materials into a blast furnace according to the present invention, FIG. 2 is a skeleton diagram of the vicinity of the top of a blast furnace to which an embodiment of the present invention is applied, and FIG. ,
It is a V diagram showing the relationship between the opening time and opening degree of the large bell. 1...small bell, 2...large bell, 6...
Hydraulic cylinder, 7... Hydraulic unit, 8... Solenoid valve, 10... Movable armor, 11.
...Flow control valve, 12...Furnace top sequence control device, 13...Pulse transmitter, 14...Large bell opening time/opening degree setting input panel.

Claims (1)

[Claims] (1) In a blast furnace charging method in which the charging material is charged into the furnace while adjusting the opening speed of the bell located at the lowest level among the bells installed at the top of the blast furnace, A procedure for calculating the opening speed deviation from the set opening speed and the actual opening speed, a procedure for calculating the corrected opening speed based on this opening speed deviation, and a procedure for correcting the set opening speed by this corrected opening speed. , and a step of setting this as the next set opening speed.