JPH0733529B2 - Raw material load calculation method and raw material charging method in bellless top charging device - Google Patents

Description

Detailed Description of the Invention

TECHNICAL FIELD The present invention relates to a raw material load calculation method capable of accurately calculating the raw material load of each hopper in a bellless furnace top charging device having two or more hoppers installed in parallel, and the above. The present invention relates to a raw material charging method using a bellless furnace top charging device capable of charging raw materials into the furnace in a uniform distribution from the bellless furnace top charging device.

[Prior art]

A bellless charging device is known as a furnace top charging device for charging raw materials into a blast furnace. FIG. 4 is a schematic explanatory view showing an example of a raw material charging method from a bellless charging device to a blast furnace. When charging raw material into the blast furnace 10 from the hopper 12, the hopper
12 is charged with raw material, the raw material is weighed with a load cell 14, then the flow rate adjusting gate 16 is adjusted to an opening degree corresponding to the raw material amount, the seal valve 18 is opened, and the raw material is fed at a predetermined speed to the blast furnace 10. Charge to the furnace top of. The raw materials that are sequentially charged to the top of the furnace should be operated under stable furnace conditions.
It is distributed by the swirling chute 20 so as to have an even distribution in the blast furnace. As described above, in order to distribute the raw material in the blast furnace 10 in an even distribution, for example, the turning end of the turning chute 20 and the chute 20
It is necessary to match the end of the discharge of the raw materials from the hopper 12, that is, to complete the distribution of all the raw materials from the hopper 12 with just the planned number of turns of the turning chute 20. For that purpose, it is important to accurately weigh the raw material loaded in the hopper 12 and set the gate 16 at an appropriate opening degree corresponding to the raw material amount. By the way, the raw material is weighed by the load cell 14 as described above, but in the bellless charging device, the raw material is fed to the first expansion joint tube 24 for connection between the hopper 12 and the receiver 22 and the upper portion of the hopper 12. A second expandable joint pipe 26 for exhaust is continuously provided. Therefore, when the pressure in the hopper 12 increases, thrust is generated in the expandable portions 24A, 26A of the first and second expandable joint pipes 24, 26, and when the total weight of the hopper 12 increases, the beam receiving ( (Structure) 28 is deflected and the hopper 12 is displaced downward, so that a spring reaction force is generated in both of the elastic portions 24A and 26A.
When weighing the raw material in the hopper 12, with respect to the measurement value by the load cell 14, the both expansion and contraction section 24A, 26A
In order to improve the weighing accuracy, a correction was made in consideration of the influence of (Japanese Patent Laid-Open No. 62-156527).

[Problems to be achieved by the invention]

However, when the bellless charging device has a configuration in which two or more hoppers are arranged in parallel on the same structure, when the raw material loaded in one hopper is to be weighed by the load cell, the load cell In addition to the thrust force and the spring reaction force of the expansion and contraction portions 24A and 26A of the hopper, the influence of other hoppers arranged in parallel is added to the measured value by. That is, the material load in the other hopper, deflection due to the thrust force and spring reaction force due to the expansion and contraction portion thereof, and the like, the structure is deflected, and the deflection affects the measurement value of the load cell for the one hopper. It will be. The above relationship will be specifically described in the case of a bellless charging device in which, as shown in FIG. 5, three hoppers I to III are installed in parallel on the same beam (structure) 28. FIG. 6 is a plot of the output values (measured values) of the load cells 14 of the respective hoppers over time, focusing on the hoppers I and II in the bellless charging device. The upper and lower rows of FIG. 6 are hopper I and hopper II, respectively.
The output value of the load cell 14 is shown. From the empty state of any hopper, the supply of the raw material to the hopper I is started at the time point A ₁ , and the supply is ended at the time point A ₂ . During that time, the output value of the load cell of hopper I increases, but the output beam of the load cell of hopper II decreases because the receiving beam 28 bends as the raw material is supplied. Next, the raw material supply to the hopper II is started at time B ₁ , and is finished at time B ₂ . During that time, since the receiving beam 28 is bent due to the increase in the weight of the hopper II, the output value of the load cell of the hopper I is decreasing. After that, in order to be able to supply the raw material into the furnace,
The internal pressure of the hopper I is increased at the time point C ₁ to start the pressure equalizing operation to match the internal pressure of the furnace, and is finished at the time point C ₂ . Meanwhile, in the hopper I, the output value of the load cell is increased by the thrust of the expansion / contraction parts 24A and 26A caused by the increase in the internal pressure, but it is decreased in the hopper II. As described above, in the bellless charging device in which a plurality of hoppers are installed in parallel, the measured value (output value) of the load cell in one hopper is the raw material load, thrust force of the expansion / contraction part, and spring reaction force in the other hoppers. However, the raw material could not be accurately weighed by simply performing a simple correction on the measured value of the load cell as in the case of a single hopper bellless charging device. As a result, it is impossible to set the gate opening and the swirling speed of the swirling chute that are appropriate for the amount of the raw material loaded in each hopper, so that the raw material cannot be charged so as to form an even distribution in the blast furnace. There was a problem. The present invention has been made to solve the above problems,
Even in a bellless charging device in which multiple hoppers are installed side by side on the same structure, it is possible to calculate the raw material load in the bellless furnace top charging device that enables highly accurate calculation of the raw materials loaded in each hopper. It is a first object to provide a method. The present invention also appropriately controls and sets the opening of the control gate or the turning speed of the turning chute based on the calculation result of the raw material load, and charges the raw material so that an even distribution can be formed in the blast furnace. It is a second object to provide a raw material charging method using a bellless furnace top charging device that enables the above.

[Means for achieving the object]

The present invention uses a bellless charging device in which two or more hoppers are arranged side by side on the same structure, and load measuring means is attached to each hopper and an expansion joint tube is connected. The raw material load loaded in the one hopper is calculated by correcting the raw material load value in the hopper by the internal pressure of the one hopper and the raw material load measurement value in another hopper and the internal pressure. This achieves the first object. Further, according to the present invention, the raw material load loaded in one hopper is calculated by the above calculation method, and the raw material loaded in the one hopper is introduced into the swirling chute installed at the furnace top through the control gate. Then, when the raw material is discharged from the turning chute into the furnace while charging while turning the turning chute a target number of times, based on the raw material load calculated, the turning end of the target number of turns of the turning chute and the turning are performed. By controlling the opening of the control gate or the turning speed of the turning chute in the one hopper so that the end of the discharge of the raw material from the chute coincides with the second hopper.
Has achieved the task of.

[Action and effect]

In the present invention, the load measurement value of the raw material in one hopper is corrected by the internal pressure of the one hopper, and the load measurement value of the raw material in another hopper and the correction by the internal pressure are performed to load the one hopper. Since the calculated raw material load is calculated, an accurate raw material load can be obtained. Then, the raw material loaded in the one hopper is introduced into a swirling chute installed at the top of the furnace through a control gate, and the raw material is discharged from the swirling chute into the furnace while rotating the swirling chute a target number of times. Then, based on the calculated raw material load, the end of turning of the target number of turns of the turning chute and the end of discharging the raw material from the turning chute are matched so that the control gate of the one hopper By controlling the opening and introducing the raw material from the one hopper into the furnace top, the raw material can be charged at an appropriate gate opening corresponding to the amount of the raw material loaded in the hopper. It is possible to supply the raw material according to the target number of turns of the turning chute installed in the. Further, similarly, by controlling the turning speed of the turning chute, it becomes possible to match the number of turns of the chute with the target even when the opening of the control gate is fixed. Therefore, it becomes possible to exactly coincide with the end of turning of the target number of turns of the turning chute and the completion of discharging the raw material from the turning chute into the furnace, and as a result, the distribution of the raw material in the circumferential direction in the furnace can be made. Since it can be carried out according to the target, the improvement of the reactor condition is achieved.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing an example of a bellless charging device applicable to one embodiment of the present invention. The bellless charging device is provided with two hoppers 12A and 12B installed in parallel above the blast furnace 10. A conveyor chute 30 is arranged above the hoppers 12A and 12B, and a raw material can be supplied to each hopper via a receiving chute 32. The raw materials supplied to and loaded into the above hoppers 12A and 12B are
Each is measured by a load cell (load measuring means) 14.
The hoppers 12A and 12B are connected to an upper receiver 34 via expansion joint tubes 24, and the upper receiver 34 is connected to a furnace top of the blast furnace 10 via a lower receiver 36. Flow rate control gate 16 for raw materials from 12A and 12B
After that, the blast furnace 10 can be charged into the furnace top. The raw materials charged from the hoppers 12A and 12B are
A swirling chute 20 installed at the top of the furnace and swung by a drive device 38 distributes it so as to form an even distribution in the furnace. As described above, in order to distribute the raw material so as to form an even distribution, for example, the end point of the planned number of turns of the turning chute 20 and the end of discharging the raw material from the chute 20 should be substantially matched. Is required, and for that purpose, for each hopper 12A, 12B, the opening of the gate 16 can be adjusted by setting an appropriate initial opening corresponding to the amount of the loaded raw material in the flow rate adjusting gate 16. Need to be properly controlled. Therefore, in order to supply the raw material into the blast furnace 10 in a uniform distribution, it is extremely important to accurately determine the raw material loaded in each hopper that serves as a reference for determining the opening of the flow rate adjusting gate 16. . Next, regarding a bellless charging device in which two or more hoppers are arranged side by side on the same structure, the raw materials loaded in each hopper are respectively considered in consideration of the measured value of the load cell and the internal pressure of each hopper. A calculation method that enables highly accurate calculation will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic explanatory view showing types of loads acting on the load cell 14 with respect to the single hopper 12. FIG. 2A shows a state in which the hopper 12 is loaded with the raw material having the load W, and the load W directly acts on the load cell 14. FIG. 2 (B) shows a case where the internal pressure P is applied to the hopper 12, and thrust is generated in each of the expansion / contraction parts 24A and 26A. Here, assuming that the proportional coefficients in the expanding and contracting portions 24A and 26A are A ₁ and A ₂ , respectively, and the angle formed with the vertical direction of the second expanding and contracting joint pipe 26 is θ, the thrust force acting on the load cell 14 due to the internal pressure P is given. L _P is given by the following equation (1). _{L P = -P × A 1 +} P × A 2 sinθ = (- A 1 + A 2 sinθ) P = K P · P (K P: constant) ... (1) FIG. 2 (C), the load W and shows a case where the deflected receiving beam 28 due to the thrust L _P and the like to the position of the dashed line (deflection amount = [delta]), in this case, each spring reaction force in the stretchable portion 24A and 26A are generated. The elastic modulus of the stretchable portion 24A K _1, the elastic coefficient K _2L tube direction of stretch unit 26A, when the elastic modulus in the direction perpendicular to the tube direction is K _2C, a spring reaction force L _E acting on the load cell 14 It is given by the following equation (2). _{L E = -K 1 δ-K} 2L δ sinθ -K 2C δ cosθ = - (K 1 + K 2L sinθ + K 2C cosθ) δ = K E · δ (K E: constant) (2) Now, according to the load cell 14 Assuming that the load measurement value of only the raw material is L _I , the raw material load W in the hopper is given by the following equation (3). W = L _I + L _P + L _E (3) Further, in the equation (2), the deflection amount δ is given by the following equation (4) when the deflection coefficient of the receiving beam 28 is F.
By substituting the expressions (1) and (2) into the expression, the expression (5) is obtained. δ = F (W + L _P + L _E ) ... (4) δ = F (W + K _P · P + K _E · δ) ∴δ = F (W + K _P · P) / (1−F · K _E ) = {F / (1 −F · K _E )} · W + {F · K _P / (1−F · K _E )} · P (5) Therefore, the raw material load W is obtained from the formula (3) as follows. It is given by the following equation (6). W = L _I + L _P + L _E = L _I + K _P · P + K _E · δ = L _I + K _P · P + K _E [{F / (1-F · K _E )} · W + {F · K _P / (1 −F · K _E )} · P] ∴W = {1-K _E · F / (1-F · K _E )} ⁻¹ × [L _I + {K _P + F · K _E · K _P / (1 -F
K _E )} · P] = A · L _I + B · P (6) (A, B: coefficient) From the above formula (6), in the case of a single hopper, the raw material load W loaded in the hopper is W. Is the measured value L by the load cell
_It can be expressed as a linear function of _I and the internal pressure P. Next, a case where a plurality of hoppers are arranged side by side will be described by taking the three bell-less charging devices shown in FIG. First, considering the hopper 12 (1), the hopper 12
For the deflection amount δ ₁ of the receiving beam 28 according to (1), the other hopper 12
Deflection amounts δ ₂ and δ due to (2) and 12 (3) respectively
Affected by ₃ . Therefore, the deflection amount δ ₁ can be expressed by the following formula (7) by applying the formula (5). δ ₁ = k _1W · W ₁ + k _1P · P ₁ + k ₁₂ × δ ₂ + k ₁₃ · δ ₃ (7) where W ₁ and P ₁ are the raw material load and the internal pressure in the hopper 12 (1), Each k is a coefficient. Substituting the equation (5) for δ ₂ and δ ₃ into the equation (7), δ ₁ can be expressed as the following equation (8). δ ₁ = k _1W · W ₁ + k _1P · P ₁ + k _12W · W ₂ + k _12P · P ₂ + k _13W · W ₃ + k _13P · P ₃ (8) Where W ₂ and P ₂ are hoppers 12 (2 ) Is the weight load and the internal pressure, and W ₃ and P ₃ are the weight load and the internal pressure in the hopper 12 (3). Further, each k is a coefficient. Applying the equation (3), the raw material load W ₁ can be expressed by the following equation (9). W ₁ = L _I1 + L _P1 + K _E1 · δ ₁ (9) δ ₁ is a linear function of W _i and P _i (i = 1,2,3) according to the equation (8). That is, δ ₁ is L _i , P _i (i = 1,2,
It is a linear function of 3). Therefore, the equation (9) can be expressed by the following equation (10). W ₁ = A ₁₁ L _I1 ＋ B ₁₁ P ₁ ＋ A ₁₂ L _I2 ＋ B ₁₂ P ₂ ＋ A ₁₃ L _I3 ＋ B ₁₃ P ₃ … (10) where A _{11 to} A ₁₃ are correction factors for the measured values by the load cell, B _{11 to} B ₁₃ are correction coefficients for the internal pressure. The same operation as above is executed for each of the hoppers 12 (2) and 12 (3), and when the raw material loads W ₂ and W ₃ are obtained, these W ₂ and W ₃ are respectively equivalent to the above equation (10). It can be represented by a formula. Therefore, the hoppers 12 (1) -12 (3)
The raw material loads W _{1 to} W ₃ can be expressed as the product of the matrices shown in the following equation (11). Here, L _I1 , L _I2 and L _I3 are respectively in the hopper 12
The measured values of the load cell in (1), (2), and (3), and P ₁ , P _2, and P ₃ are the internal pressures in each hopper, respectively. In the above formula (11), an example of a combination of measurements by an actual machine when calculating each coefficient for the raw material load W ₁ is specifically shown in Table 1 below. Although it is possible to obtain each coefficient theoretically,
Since it is complicated and inferior in accuracy, it is better to obtain it as the unknown number from the measurement data of the actual machine (it goes without saying that it may be obtained theoretically). In that case, the unknown number is 18, so if 3 × 3 × 2 = 18 cases, the unknown number can be obtained. However, as shown in Table 1 below, it is desirable to focus on the case where the coefficient has a large influence. The relation of the expression (11) is also established for a bellless charging device in which an arbitrary number n of hoppers are installed in parallel on the same structure. Therefore, it can be expressed by the following general formula. Here, W _i : raw material load in the i-th hopper L _i : measured value of load cell in the i-th hopper P _i : internal pressure in the i-th hopper A _ij : coefficient for multiplying Li _i coefficient for multiplying B _ij : P _i As described above, in the bellless charging device in which two or more hoppers are arranged in parallel, the weighing is performed by the product of the vector having the measured value L _i and the internal pressure P _i of the load cell in each hopper and the correction matrix for each component. The corrected raw material load W _i in each hopper can be obtained by calculating the vector having the correction value as a component. Therefore, even for a bellless charging device in which an arbitrary number of hoppers are installed side by side, it is possible to accurately determine the raw material load in each hopper, so that the flow rate adjustment gate under each hopper is set based on the raw material load. It is possible to control to an appropriate opening (for example, to set the initial opening to a predetermined opening). As a result, it is possible to match the end of the target number of turns of the swirling chute provided in the blast furnace with the end of discharge of the raw material charged into the furnace top through the flow rate adjusting gate and then discharged from the swirling chute. Because it will be possible
It is achieved that the raw materials are evenly distributed in the furnace according to the target. Therefore, conventionally, in the case of a bellless charging device in which a plurality of hoppers are installed in parallel, there was a concern that the distribution control of the raw material at the furnace top would not work and the furnace condition would deteriorate, but according to this embodiment, Since the target material distribution can be formed in the circumferential direction in the furnace, the furnace condition can be improved and the controllability and stability of the furnace condition can be improved. When charging the raw material into the furnace from the bellless charging device, the turning speed of the turning chute 20 may be controlled, and the gate opening is controlled by controlling the turning speed in this manner. The same effect as the case can be obtained. For example, as a result of calculating the load of the raw material loaded in the hopper, the raw material can be charged into the furnace by the swirling chute at the target number of times of swirling. When the gate opening is large, the swirling speed is also increased, so that the distribution amount of the raw material at the target position in the furnace can be appropriately adjusted. A case where the opening degree of the control gate and the turning speed of the turning chute are controlled will be described with a specific example. Now, it is assumed that it is set as a standard to load 120 tons of ore loaded in the hopper into the furnace by turning the turning chute 12 times a target number of times in 100 seconds. If the ore in the hopper calculated from the measured value of the load cell by the above-mentioned method exceeds 120t, the turning speed should be fixed and the gate opening should be increased to make the charging end coincide with 100 seconds. Or, fix the gate opening and reduce the turning speed so that 12 turns can be achieved after 100 seconds. Conversely, if the ore in the hopper is less than 120 tons, fix the turning speed and lower the roll opening so that the charging time matches 100 seconds, or fix the gate opening and change the turning speed. Raise it so that 12 turns are achieved earlier than 100 seconds. By executing the above-described control operation any number of times within one raw material charging time, it is possible to always match the end of raw material charging with the end of the turning of the target number of turning shoots. Although the present invention has been specifically described above, it is needless to say that the present invention is not limited to the above-mentioned embodiments. For example, the load measuring means is not limited to the load cell, and various means having the same function can be used, and the concrete structure of the bellless charging device can be variously changed.

[Brief description of drawings]

FIG. 1 is a front view showing a bellless charging device applicable to one embodiment of the present invention, and FIG. 2 is a schematic explanatory view showing kinds of loads acting on a load cell in the case of a single hopper, FIG. 3 is a schematic explanatory view for explaining a load acting on the load cell in the case of three parallel hoppers, FIG. 4 is a schematic configuration diagram showing a bellless charging device of a single hopper, and FIG. FIG. 6 is a schematic configuration diagram showing a main part of a bellless charging device for explaining the prior art, and FIG. 6 is a diagram showing an output of a load cell in the bellless charging device of FIG. 10 …… Blast furnace, 12 …… Hopper, 14 …… Load cell, 16 …… Flow adjustment gate, 20 …… Swivel chute, 24,26 …… Expansion joint pipe, 28 …… Bee beam.

Claims (2)

[Claims] 1. A bellless charging device in which two or more hoppers are arranged in parallel on the same structure, and each hopper is provided with a load measuring means and an expansion joint pipe is connected thereto, For the load measurement value of the raw material in the hopper, the raw material load loaded in the one hopper is calculated by performing the correction by the internal pressure of the one hopper and the correction of the raw material load value in the other hopper and the internal pressure. A method for calculating a raw material load in a bellless furnace top charging device, comprising: 2. A bellless charging device in which two or more hoppers are arranged in parallel on the same structure, and a load measuring means is attached to each hopper and an expansion joint pipe is connected thereto. For the load measurement value of the raw material in the hopper, the raw material load loaded in the one hopper is calculated by performing the correction by the internal pressure of the one hopper and the correction of the raw material load value in the other hopper and the internal pressure. Then, the raw material loaded in the one hopper is introduced through a control gate to a swirling chute installed at the top of the furnace, and the raw material is discharged from the swirling chute into the furnace while rotating the swirling chute a target number of times. Then, based on the calculated raw material load, the above-mentioned one hook is set so that the end of turning of the target number of turns of the turning chute and the end of discharging the raw material from the turning chute coincide with each other. Material charging method in bell-less furnace ItadakiSo input apparatus characterized by controlling the opening or rotation speed of the rotating chute control gate in.