JPH0438804B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to controlling the opening degree of a raw material control gate used for charging lump-like raw materials from the top of a bellless blast furnace, general shaft furnace, etc. into a furnace. This relates to an adjustment method.

[Prior Art] A general furnace top charging device for charging lumps and granular raw materials such as iron ore and coke into the furnace from the top of a bellless blast furnace is as shown in FIGS. 3 and 4, for example. , raw material 22 conveyed by belt conveyor 21
The raw material control gate 23 is temporarily stored at the bottom.
242 furnace top hoppers installed in parallel (Fig. 3),
Alternatively, they may be arranged in series (Fig. 4), and a distribution chute drive device 26 is provided above the furnace body 25, and the distribution chute drive device 26 drives the distribution chute and rotates the inside of the furnace at a constant speed with the center of the furnace body as the center. The structure includes a distribution chute 27 whose inclination angle can be adjusted in both directions. In addition, 28 in the figure is the lower seal valve,
29 is an upper seal valve.

The operation of the furnace top charging device is often carried out using a programmable controller.
The opening degree of the raw material control gate 23 is also set using this programmable controller. The setting method is to first set the gate opening to be used using the "raw material control gate opening table".
Register. Normally, the gate opening number is set between 1 and 10, and the opening angle is set to correspond to this number, for example, No. 1: 30°, No. 2: 33°, No. 3: 35°, etc. ,
Set and input the opening degree of the raw material control gate into the "dump mode table". Dumping refers to charging a certain amount of raw material into the furnace at once. Furthermore, input the opening number of the raw material control gate when executing the dump. For example, for No. 1 dump truck, gate opening is No. 1, and for No. 2 dump truck, gate opening is No. 1.
If you enter 2, the opening degree of the raw material control gate 23 will be 30 degrees when executing the No. 1 dump, and the opening degree of the raw material control gate 23 will be 30 degrees when executing the No. 2 dump.
It becomes 33°.

When charging raw materials into a furnace, it is customary to separate them into coke and iron ore and charge them separately. In addition to setting the opening degree of the raw material control gate 23 as shown in FIG. , so that the total number of turns of the distribution chute 27 becomes an integer. In this case, the distribution chute 27
Since the turning speed (t seconds/turning) is constant, once the total number of turns (N) is determined, the turning time, that is, the raw material discharge time (T), becomes T = N × n (seconds),
It is a certain value.

However, when the charging operation is actually carried out, there may be an excess or deficiency in the amount of raw material cut out during the discharge time, or an excess or deficiency in the number of revolutions of the distribution chute 27 at the time of completion of raw material cutting, and as a result, the raw material in the furnace may be Distribution becomes uneven. Recently, blast furnace operation has been
Systems that use AI (artificial intelligence) are increasingly being implemented, and one of the key points is controlling the flow distribution of gas in the reactor in the radial direction of the reactor body. The distribution of raw materials in the furnace is an important point as a means of controlling blast furnaces, and there was a problem that stable operation of the blast furnace could not be ensured unless the planned distribution of raw materials was achieved.

The causes of the above problem are as follows: (1) Because there is insufficient understanding of the time when raw material cutting actually starts and the time when it is completed, there is a gap between the actual raw material discharge time and the rotation time of the distribution chute 27; (2) The amount of raw material stored in the furnace top hopper 24 cannot be accurately grasped, or the furnace top hopper 24
(3) The opening degree of the raw material control gate 23 may be inappropriate due to various changes in the particle size of the raw material, and the above problems may be resolved. For (1)
Placing an acoustic or vibration detector on the inlet side of the distribution chute 27; (2) In addition to the above, placing a mass meter on the top hopper 24; and (3) opening the raw material control gate 23 based on past accumulated data. Measures were taken such as setting a
Publication No. 47728, Special Publication No. 59-38424, Special Publication No. 1987
-Refer to Publication No. 52404).

[Problems to be Solved by the Invention] However, despite implementing the above countermeasures, the error in the number of turns is ±0.5 to ±1.0 turns for the number of turns of the distribution chute 27, which is approximately 14 times per dump, and in severe cases. The number of turns reached ±2 in some cases, and it was recognized that further improvements were needed.

The inventor of this case focused on the unreasonableness of correcting the gate opening degree of the raw material control gate 23 based only on past accumulated data because the particle size distribution width of the raw material was unexpectedly large, and developed a raw material Before loading, compare the raw material discharge speed at the previous charging time and the gate opening degree of the raw material control gate 23 at that time with a preset standard discharge characteristic value,
A new method for setting the opening degree of the raw material control gate 23 for the next time has been invented. The gist of the invention will be explained below.

The raw material to be charged into the blast furnace is stored in a plurality of raw material bins, and the amount equivalent to one dump is sequentially cut out from the raw material bins and supplied to the blast furnace. Therefore, the remaining raw material in a raw material bin gradually decreases, and when it reaches a certain amount, it is switched to another raw material pin and cutting continues, and during this time, raw materials with a small remaining amount are used in preparation for the next cutting. The cycle of refilling the bottle with raw materials is repeated.

On the other hand, the average particle size of raw materials, especially coke, is about 50〓, and the individual particle sizes are widely distributed between 10〓 and 70〓. Similar to fluid storage, many fine particles are deposited in the center of the raw material bottle and large lumps are deposited on the outside. Therefore, the mixing ratio of fine particles and large lumps in the raw material cut out from the raw material bottle changes significantly before and after the raw material is cut out. Therefore, the conventional method of setting the gate opening degree of the raw material control gate using average accumulated data is applicable only to raw materials having an average particle size mixing ratio, and the above-mentioned rotation number This is causing errors. On the other hand, according to the present invention, corrections can be made in accordance with previous performance data, and accurate gate opening control of the raw material control gate can be expected.

[Means for Solving the Problems] The present invention has been made based on the above-mentioned considerations, and has been made in order to provide a method for setting the gate opening degree of the raw material control gate with high accuracy. A standard that expresses the relationship between the raw material control gate opening degree and raw material discharge rate for each raw material brand in the method of adjusting the opening degree of the raw material control gate when charging and distributing bulk and granular raw materials into the furnace via the control gate and distribution chute. The discharge characteristic curve is set in advance, and the raw material discharge rate at the time of the previous raw material charging is compared with the value of the raw material discharge rate on the previous standard discharge characteristic curve at the actual raw material control gate opening at that time, and the deviation value is calculated. The deviation value is subtracted from the next scheduled raw material discharge rate to determine the next raw material discharge rate, and the opening degree of the raw material control gate corresponding to the determined next raw material discharge rate is determined using the reference discharge characteristic curve. The gate opening is used as the next raw material control gate opening.

[Function] Before charging the raw material, the raw material discharge rate from the previous charging is ascertained, and the next raw material control gate opening degree is adjusted by comparing it with the standard discharge characteristic curve, so the particle size mixing in the furnace top hopper is controlled. Even if the ratio changes significantly, the gate opening degree can be set accurately, and the error in the number of turns of the distribution chute can be minimized.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show an example of an apparatus for carrying out the method of the present invention, in which a weighing hopper 1 is disposed under a raw material storage tank (not shown).
and a weighing device 2 that weighs the raw material in the weighing hopper 1.
and a weighing device 3 which aggregates the measurement results of the weighing device 2 and outputs the weight WiKg of the raw material for each dump loaded into the blast furnace as an electric signal a, and a weighing device 3 disposed at the top of the furnace body (not shown). , a furnace top hopper 5 that temporarily stores raw materials and has a raw material control gate 4 at the bottom, an actuator 6 that operates the raw material control gate 4, and an actuator 6 that operates the raw material control gate opening degree θ _i in conjunction with the actuator 6. a gate opening transmitter 7 that outputs as an electric signal b;
Directly below the furnace top hopper 5, there is a distribution chute 8 for dispersing raw materials into the furnace, and a setting device 9 for inputting and storing the total number of lines N for each dump of the distribution chute 8 and outputting it as an electric signal c. The previous charging raw weight actual value W _i for each dump truck is input as an electric signal a for each raw material brand M, and the total number of rotations N, the opening degree θ _i of the raw material control gate 4, and the raw material A memory unit 10 inputs and stores the discharge time T _i as electric signals c, b, and d and outputs them as an electric signal e, and calculates the opening degree θ of the raw material control gate and the raw material for each raw material brand M based on the accumulated past information. The standard discharge characteristic curve A shown in FIG. 2, which is a function of the relationship between the discharge speeds Q, is stored, and calculations are performed based on the electric signals e of various data inputted from the memory section 10, and the calculation results are calculated. A calculating section 11 calculates the raw material control opening degree for the next raw material charging in comparison with the standard discharge characteristic curve A, and outputs the set opening degree as an electric signal f; The next dump execution mode setting device 12 memorizes the inclination angle of the distribution chute 8, the number of revolutions N, and the opening degree θ of the material control gate at the time, and outputs it as an electric signal g, and inputs the electric signal g and issues a command to start material charging. It consists of a raw material control gate opening degree controller 13 that transmits the electric signal h as an electric signal h.

Note that the above-mentioned standard emission characteristic curve A shown in FIG. 2 is provided for each brand of raw material used in the blast furnace. Furthermore, an acoustic or vibration detector, a mass meter, or the like may be used to measure the raw material discharge time T _i . Further, the subscript i is the measured value of the dump dump that has been completely charged from the furnace top hopper 1, and i+1 is the actual value or planned value when the same brand of raw material that was charged at the completion of the i-th charging is to be charged next time.

The actual measured value W _i of the weight of the previous charged raw material stored in the memory unit 10, the actual measured value T _i of the discharge time of the previously charged raw material,
When the previously charged raw material discharge speed Q _i , the next measured raw material weight W _i+1 , and the total number of revolutions N of the distribution chute at the previous charging time are input to the calculation unit 11 as an output electric signal e, the calculation unit 11 From the above data and the fixed value distribution chute rotation speed t (seconds/turn), the previous charging material discharge speed Q i and the next charging material discharge speed Q _i can be calculated according to the following equations (1) and (2). Calculate the raw material discharge rate Q _i+1 .

Q _i = W _i /T _i Kg/sec (1) Equation Q _i+1 = W _i+1 / (N+t) Kg/sec (2) Equation This calculation result is input to the calculation unit 11,
Compare with the standard emission characteristic curve A for the same brand of raw material.
For example, when entering the coordinates of the previous raw material control gate opening θ _i and the previously charged raw material discharge speed Q _i , the intersection of the two axes is not at point A of the standard discharge characteristic curve A in Figure 2, but is off by ΔQ. If it is at point B, it means that the properties of the raw material when the standard discharge characteristic curve A was created and the properties of the previously charged raw material have changed, and in the method of the present invention, the opening degree θ of the raw material control gate is Assuming that the discharge characteristics of raw materials are approximate even if they fluctuate, a curve B passing through point B shown in Figure 2 and parallel to the standard discharge characteristic curve A is assumed, and this curve B is used as the discharge characteristic curve of the raw materials currently in use. By considering this, the deviation ΔQ, which is the cause of the error in the total number of turns of the distribution chute, is eliminated.

Next, find the intersection point D between the next charging raw material discharge rate Q _i+1 obtained by the above calculation and the curve B, and θ ₂ on the perpendicular line passing through the intersection D is the opening of the raw material control gate at the next raw material charging time. degree. It is not the opening degree θ ₁ obtained from the intersection point C of Q _i+1 and curve A.

In the method of the present invention, the next charging raw material discharge rate Q _i+1 is corrected and compared with the standard discharge characteristic curve A to obtain the raw material control gate opening degree for the next raw material charging.

The next charging material discharge speed correction value Q _{is is} calculated by the following equation (3) from the next charging material discharge speed _i+1 , the previous charging material discharge speed deviation value ΔQ, and the previous charging material discharge speed correction value Q ₀ . Calculate according to.

Q _iS = Q _i+1 −ΔQ=Q _i+1 −(Q _i −Q ₀ ) (3) Equation When comparing this calculation result with the standard emission characteristic curve A in Figure 2, the intersection E with the curve A can be found. and the intersection E
θ ₂ on the perpendicular line passing through is the opening degree of the raw material control gate when charging the next raw material.

Generally, the properties of the raw material discharged from the storage tank change with each dump. Normally, one tank is drained 16 to 20 times, and when a certain level of remaining capacity is reached, it is switched to another storage layer and then refilled. Therefore, even if the same brand of raw material is used, its properties will be significantly different between the first and 16th to 20th batches. However, the properties of the first and second times are similar,
Since the 10th and 11th times are also similar, it is possible to determine the opening degree of the raw material control gate for the next input raw material using the input results of the previous input raw material of the same brand.

Next, the operation of the raw material control gate 4 when starting to discharge raw material from the furnace top hopper and the procedure for controlling the opening degree of the gate will be explained.

When a command signal to start charging the raw material is input from the raw material control gate opening degree controller 13 to the actuator 6, the actuator 6 is activated and the raw material control gate 4 begins to open. The gate opening degree transmitter 7 connected in series sequentially outputs the gate opening degree θ of the raw material control gate 4 as an electric signal b to the raw material control gate opening degree control 13, and receives the gate opening degree θ according to the electric signal b. The raw material control gate opening degree controller 13 sets the gate opening degree θ to be the same as the raw material control gate opening degree θ ₂ at the time of the next raw material charging, which has been previously input to the dump execution mode setting device 12. At this point, a command to stop the operation of the raw material control gate 4 is sent to the actuator 6, and the raw material control gate opening degree θ is maintained at a predetermined opening degree _θ2 . At this time, due to equipment operating errors, etc.
Since a slight error will occur in the gate opening degree, in order to reflect this influence in the setting of the raw material control gate opening degree the next time the raw material is charged, input the actual gate opening degree θ _i+1 ′ into the memory section. The memory section does not store the gate opening setting value θ _i+1 output by the calculation section.
Store θ _i+1 ′ and save [W _i+1 , θ _i+1 ′, T _i+1 ].

We compiled a variety of information accumulated in the past regarding the various raw materials used in blast furnaces, compared and examined the standard discharge characteristic curve created for each raw material brand with the actual value of the raw material discharge rate during the previous charging, and calculated the deviation value between the two. The standard discharge characteristic curve is adjusted accordingly, and the raw material control gate opening degree is automatically set each time raw material is charged, so that the particle size mixing ratio of the raw material in the furnace top hopper is adjusted. Even if there is a large change, it is now possible to accurately set the gate opening to follow this change, and it is now possible to minimize errors in the number of turns of the distribution chute.

It should be noted that the present invention is not limited to the above-mentioned embodiments; for example, the standard discharge characteristic curve is modified based on the latest data stored in the memory section, and the latest properties of the charged raw material are updated. It goes without saying that the characteristic curve reflecting the above may be changed, and that various other changes may be made without departing from the gist of the present invention.

[Effects of the Invention] As explained above, according to the method for adjusting the opening degree of the raw material control gate of the present invention, various excellent effects as described below can be achieved.

() There is no need to reset the opening degree of the raw material control gate.

() The excess or deficiency in the number of turns of the distribution chute for each dump truck is minimized.

() Can follow changes in raw material properties.

() The effects of the previous () () () () on blast furnace operation are enormous.

[Brief explanation of drawings]

1 and 2 show an embodiment of the method for adjusting the opening of the raw material control gate of the present invention, FIG. 1 is a block diagram of a calculation device for carrying out the method of the present invention, and FIG. are standard emission characteristic curve diagrams for carrying out the method of the present invention, FIGS. 3 and 4.
The figure is a conceptual diagram of a general furnace top charging device. In the figure, 1 is a weighing hopper, 3 is a weighing device, 4 is a raw material control gate, 5 is a furnace top hopper, and 6
is the actuator, 7 is the gate opening transmitter, 8
1 is a distribution chute, 10 is a memory section, 11 is a calculation section, 12 is a dump execution mode setting device, and 13 is a raw material control gate opening degree controller.

Claims (1)

[Claims] 1. In the method of adjusting the opening of the raw material control gate when charging and distributing lumpy and granular raw materials into the furnace from the furnace top hopper through the raw material control gate and distribution chute, the raw material control gate opening and raw material discharge for each raw material brand are A standard discharge characteristic curve representing the speed relationship is set in advance, and the raw material discharge rate at the time of previous raw material charging is compared with the value of the raw material discharge rate on the previous standard discharge characteristic curve at the actual raw material control gate opening at that time. Then, calculate the deviation value, subtract the deviation value from the next planned raw material discharge rate to determine the next raw material discharge rate, and use the reference discharge characteristic curve to determine the opening degree of the raw material control gate corresponding to the determined next raw material discharge rate. A method for adjusting the opening degree of a raw material control gate, characterized in that the obtained gate opening degree is used as the next raw material control gate opening degree.