A precise control method for discharging under the blast furnace trough

Abstract

The application discloses a kind of accurate control methods of blast furnace tank under discharge, comprising the following steps: a. install blast furnace tank under discharge device;B. read empty hopper scale value, determine the hopper scale discharge amount set value, calculate full hopper scale value, set the initial value of material stopping advance u;C. update full hopper scale value;D. update empty hopper scale value;E. calculate the actual discharge value of hopper scale;F. calculate hopper scale discharge error;G. calculate hopper scale loading comprehensive set value;H. update full hopper scale value, calculate hopper scale loading error;I. update empty hopper scale value;J. the value of material stopping advance u is corrected;K. repeat step e-step j, until the total discharge amount reaches predetermined value stops.The application uses all parameters and discharge characteristics affecting the discharge process to recalculate the material stopping advance after each discharge of hopper scale, timely corrects discharge deviation, completely solves the discharge error problem, improves the batching accuracy of blast furnace, and ensures product quality.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of high-precision control method of blast furnace tank under discharge, can completely solve the problem of discharge error, can improve the batching accuracy of blast furnace, ensure product quality, belong to metallurgical technology field. BACKGROUND

[0002] There are about 20 batching bins under the blast furnace tank, such as sinter bin, lump ore bin and coke bin. Each bin automatically discharges according to the set value. The discharge method is as follows: first, start the feeder and vibrating screen at the lower part of the bin, and discharge the material in the bin to the hopper scale at a certain speed. The hopper scale weighs the material in real time. When the weight of the material entering the hopper scale reaches the set value, the feeder and vibrating screen stop running, the gate at the bottom of the hopper scale is opened, and the material in the hopper scale is discharged to the upper belt conveyor. The upper belt conveyor feeds the material into the blast furnace, completing a discharge. Repeat the above process until the total discharge reaches the predetermined value. Since the residual material in the vibrating screen will still fall into the hopper scale after the vibrating screen stops running, and the feeder and vibrating screen will stop when the weight of the hopper scale reaches the set value, the discharge amount may exceed the set value. To solve the problem of material over-discharge, the operator needs to set a stop discharge advance for each bin to stop the feeder and vibrating screen in advance to ensure that the discharge amount is close to the set value. However, due to factors such as material particle size and moisture, a fixed stop discharge advance cannot adapt to changes in material, resulting in a large or small discharge amount each time, i.e., the discharge error is always positive or negative. The cumulative error of multiple discharges can sometimes reach more than 300 kg, seriously affecting the batching accuracy of the blast furnace and reducing product quality. After the discharge error exceeds the limit and an alarm is triggered, the operator can only manually set the stop discharge advance for each of the 20 batching bins based on the positive and negative values and sizes of the discharge error. This not only increases the workload of the operator and affects the smooth progress of production, but also cannot fundamentally solve the problem of error exceeding the limit. Therefore, how to completely solve the problem of discharge error has been a difficult problem for relevant personnel. SUMMARY

[0003] The present application aims to solve the problems of the prior art and provide a high-precision control method for blast furnace tank under discharge to completely solve the problem of discharge error and improve the batching accuracy of the blast furnace.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A high-precision control method for blast furnace tank under discharge, the method comprising the following steps:

[0006] a. Install a blast furnace tank under discharge device:

[0007] A feeder, a vibrating screen, a hopper scale and a feeding belt are installed in turn under the discharge port at the bottom of the bin 1, and a gate is installed at the bottom discharge port of the hopper scale;

[0008] b. Read the weighing value of the hopper scale when there is no material in the hopper scale, and record it as the empty hopper scale value W 空 , determine the hopper scale discharge setting value W 设 , calculate the full hopper scale value W 满 = W 设 +W 空 , set the initial value of the stop material advance u;

[0009] c. Start the feeder and the vibrating screen to transport material to the hopper scale, when the weighing value of the hopper scale reaches W 满 -u, stop the feeder and the vibrating screen, when the remaining material on the vibrating screen is discharged, take the weighing value of the hopper scale at this time as the new full hopper scale value W 满 , open the gate to discharge the material in the hopper scale to the feeding belt;

[0010] d. Close the gate after the hopper scale is discharged, and take the weighing value of the hopper scale at this time as the new empty hopper scale value W 空 ;

[0011] e. Calculate the actual hopper scale discharge value W 实 :

[0012] W 实 = W 满 -W 空 ;

[0013] f. Calculate the hopper scale discharge error E:

[0014] E = W 实 -W 设 ;

[0015] g. Calculate the hopper scale loading comprehensive setting value W 综设 :

[0016] W 综设 = W 设 -E+W 空 ;

[0017] h. Start the feeder and the vibrating screen again to transport material to the hopper scale, when the weighing value of the hopper scale reaches W 综设 -u, stop the feeder and the vibrating screen, when the remaining material on the vibrating screen is discharged, take the weighing value of the hopper scale at this time as the new full hopper scale value W 满 , calculate the hopper scale loading error e:

[0018] e = W 满 -W 综设 ;

[0019] i. open the gate, discharge the material in the hopper scale to the feeding belt, close the gate after the hopper scale is discharged, take the weighing value of the hopper scale at this time as the new empty hopper scale value W 空 ;

[0020] j. correct the value of the stop material advance u: set the value of the coefficient a, add the stop material advance u and ae to obtain the new stop material advance u;

[0021] k. repeat steps e-j until the total discharge amount reaches the predetermined value.

[0022] The above-mentioned precise control method of the discharge of the blast furnace tank sets the value range of the stop material advance u:

[0023] u min ≤u≤u max

[0024] In the formula, u min is the lower limit value of the stop material advance, and u max is the upper limit value of the stop material advance. When the value of the stop material advance u is corrected, if the new stop material advance u obtained is less than u min , the value of u is u min , and if the new stop material advance u obtained is greater than u max , the value of u is u max .

[0025] The above-mentioned precise control method of the discharge of the blast furnace tank sets the upper limit value u max of the stop material advance as W 设 ×10%, and sets the lower limit value u min of the stop material advance as -W 设 ×10%.

[0026] The above-mentioned precise control method of the discharge of the blast furnace tank sets the value range of the coefficient a as 0

[0027] The above-mentioned precise control method of the discharge of the blast furnace tank sets the initial value of the stop material advance u as 0.

[0028] The present application re-calculates the stop material advance by using all the parameters and discharge characteristics affecting the discharge process after the hopper scale is discharged each time, so that it can adapt to the changes of the physical properties of the material, automatically and timely corrects the discharge deviation of each bin, completely solves the discharge error problem, improves the batching accuracy of the blast furnace, and ensures the product quality. BRIEF DESCRIPTION OF DRAWINGS

[0029] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0030] Figure 1This is a schematic diagram of the blast furnace trough discharge device.

[0031] The following are the labels in the diagram: 1. Hopper, 2. Feeder, 3. Vibrating screen, 4. Hopper scale, 5. Gate, 6. Feeding belt conveyor.

[0032] The symbols in the text are as follows: W 空 W is the empty bucket scale value. 设 W is the set value for the discharge capacity of the hopper scale. 满 W represents the full capacity of the bucket scale, where u is the material stopping lead time. 实 E represents the actual discharge value of the hopper scale, and W represents the discharge error of the hopper scale. 综设 Here, e represents the overall setting value for hopper scale loading, a is the loading error of hopper scale, and u is the coefficient. min This is the lower limit of the material stoppage lead time, u max This is the upper limit of the lead time for material stoppage. Detailed Implementation

[0033] This invention provides a precise control method for blast furnace trough discharge. This method can automatically and promptly correct the discharge deviation of each bin, achieve precise discharge of blast furnace trough discharge bins, improve the accuracy of blast furnace feed ratio, and reduce the repetitive workload of operators.

[0034] See Figure 1 The blast furnace trough discharge device of this invention includes, from top to bottom, a hopper 1, a feeder 2, a vibrating screen 3, a hopper scale 4, and a charging conveyor belt 6. A gate 5 is located at the bottom of the hopper scale 4. During discharge, the feeder 2 and vibrating screen 3 are started first, discharging the material from the hopper 1 into the hopper scale 4 at a certain speed. The hopper scale 4 collects the material discharged from the vibrating screen 3 and weighs the material in real time. When the weight of the material entering the hopper scale 4 reaches a set value, the feeder 2 and vibrating screen 3 stop operating, the gate 5 at the bottom of the hopper scale 4 is opened, and the material in the hopper scale 4 is discharged onto the charging conveyor belt 6. The charging conveyor belt 6 then feeds the material into the blast furnace, completing one discharge cycle. This process is repeated until the total discharge volume reaches a predetermined value.

[0035] During each batch of material discharge from the trough, the bins to be discharged are selected. Under the control of the control system, the feeder 2, vibrating screen 3, hopper scale 4, and gate 5 below the selected bins sequentially convey materials to the feeding conveyor 6 according to the discharge setting value. However, due to the influence of factors such as material particle size, humidity, and residual material on the vibrating screen, simply discharging according to the discharge setting value results in a large error and unstable discharge. Since the changes in material particle size, humidity, and vibrating screen conditions are continuous and there are basically no large abrupt changes, based on the above situation, the technical solution of this invention is to enable the material stop advance amount to adapt to the discharge situation and achieve the purpose of accurate material discharge.

[0036] This invention includes the following steps:

[0037] a. Install the blast furnace tank under the discharge device:

[0038] The feeder 2, the vibrating screen 3, the hopper scale 4 and the feeding belt conveyor 6 are sequentially installed below the discharge port at the bottom of the bin 1, and the gate 5 is installed at the bottom discharge port of the hopper scale 4;

[0039] b. Read the weighing value of the hopper scale 4 when there is no material, and record it as the empty hopper scale value W 空 , determine the hopper scale discharge amount set value W 设 , calculate the full hopper scale value W 满 = W 设 +W 空 , the full hopper scale value refers to the weighing value when the hopper scale 4 is full of material; set the initial value of the stop material advance amount u, which can be set to 0;

[0040] c. Start the feeder 2 and the vibrating screen 3 to transport material to the hopper scale 4, when the weighing value of the hopper scale 4 reaches W 满 -u, stop the feeder 2 and the vibrating screen 3, when the remaining material on the vibrating screen 3 is discharged, take the weighing value of the hopper scale 4 at this time as the new full hopper scale value W 满 , open the gate 5 to discharge the material in the hopper scale 4 to the feeding belt conveyor 6;

[0041] d. Close the gate 5 after the hopper scale 4 is discharged, and take the weighing value of the hopper scale 4 at this time as the new empty hopper scale value W 空 ;

[0042] e. Calculate the actual hopper scale discharge value W 实 :

[0043] W 实 = W 满 -W 空 ;

[0044] f. Calculate the hopper scale discharge error E:

[0045] E = W 实 -W 设 ;

[0046] g. Calculate the hopper scale loading comprehensive set value W 综设 :

[0047] W 综设 = W 设 -E+W 空 ;

[0048] h. Start the feeder 2 and the vibrating screen 3 again to transport material to the hopper scale 4, when the weighing value of the hopper scale 4 reaches W 综设When u, the feeder 2 and the vibrating screen 3 are stopped, and when the residual material on the vibrating screen 3 is discharged, the weighing value of the hopper scale 4 at this time is taken as a new full hopper weighing value W 满 The hopper scale loading error e is calculated:

[0049] e = W 满 -W 综设 ;

[0050] i. The gate 5 is opened, and the material in the hopper scale 4 is discharged onto the feeding belt conveyor 6. After the hopper scale 4 is discharged, the gate 5 is closed, and the weighing value of the hopper scale 4 at this time is taken as a new empty hopper weighing value W 空 ;

[0051] j. The value of the material stopping advance u is corrected. The value of the coefficient a is set, the material stopping advance u is added to ae, and a new material stopping advance u is obtained. The corrected material stopping advance u is taken as the material stopping advance of the next time;

[0052] k. Steps e-j are repeated until the total discharge amount reaches a predetermined value.

[0053] The value of the coefficient a can be adjusted according to specific control conditions. The maximum value range of the coefficient a is 0

[0054] To prevent the material stopping advance from being too large due to the hopper scale loading error being too large in special cases, the value range of the material stopping advance u is set as:

[0055] u min ≤ u ≤ u max

[0056] In the formula, u min is the lower limit value of the material stopping advance, and u max is the upper limit value of the material stopping advance. When the value of the material stopping advance u is corrected, if the new material stopping advance u obtained is less than u min , the value of u is u min , and if the new material stopping advance u obtained is greater than u max , the value of u is u max .

[0057] The value range of the material stopping advance u is set as:

[0058] -W 设 ×10% < u < W 设 ×10%.

[0059] In the control system, each bunker under the trough corresponds to a device control screen, and the control mode of the stop material advance u is selected in the screen, if the constant is selected, the set stop material advance u initial value is used to control the feeder and the vibrating screen, and the control mode can be selected when the abnormal situation occurs, if the calculated value is selected, the stop material advance u of each time of material discharge is calculated according to the formula, so that the self-adaptive control is realized, and the purpose of precise material discharge control is achieved.

[0060] The stop material advance initial value and the hopper scale material discharge set value W 设 can be set in the device control screen, and the calculated values of the stop material advance, the hopper scale charging error and the hopper scale material discharge error can also be displayed.

[0061] The present application calculates the stop material advance u each time, so that the material discharge amount of the feeder 2 and the vibrating screen 3 can automatically adapt to the change of the physical properties of the material, such as the change of the material particle size and humidity, and the calculation process of the stop material advance u contains all parameters and material discharge characteristics affecting the material discharge process, such as the full hopper scale value W 满 , the empty hopper scale value W 空 , the actual hopper scale material discharge value W 实 and the hopper scale material discharge error E, so that the material discharge deviation of each bin can be automatically and timely corrected, the precise material discharge control under the trough is realized, and the blast furnace material proportioning precision is improved.

[0062] Taking the sintering material bin material discharge process as an example, the calculation process between the variables and the meaning and value taking method of the variables are described. The appropriate stop material advance is calculated each time of material discharge, and the effect of precise material discharge is achieved. The specific implementation steps are as follows:

[0063] a. The feeder, the vibrating screen, the hopper scale, the gate and other devices are installed on the site. The DCS control system is installed in the electrical room. The DCS is installed in the DCS cabinet, the operation station and the engineer station are installed in the main control room, and the DCS controller, the operation station and the engineer station are connected through the Ethernet.

[0064] b. The empty hopper scale value W 空 is read, the hopper scale material discharge set value W 设 is determined, the full hopper scale value W 满 is calculated, and the initial value of the stop material advance u is set.

[0065] c. The feeder 2 and the vibrating screen 3 are started, when the weighing value of the hopper scale 4 reaches W 满 -u, the feeder 2 and the vibrating screen 3 are stopped, when the residual material on the vibrating screen 3 is discharged, the full hopper scale value W 满 is read, the gate 5 is opened, and the material in the hopper scale 4 is discharged to the upper material belt conveyor 6;

[0066] d. The gate 5 is closed after the hopper scale 4 discharges the material, and the empty hopper scale value W空 ;

[0067] e. Calculate the actual discharge value of the hopper scale W 实 ;

[0068] f. Calculate the hopper scale discharge error E;

[0069] g. Calculate the hopper scale loading comprehensive set value W 综设 ;

[0070] h. Start the feeder 2 and the vibrating screen 3, when the weighing value of the hopper scale 4 reaches W 综设 -u, the feeder 2 and the vibrating screen 3 are stopped, when the remaining material on the vibrating screen 3 is discharged, the full hopper scale value W 满 is updated, the hopper scale loading error e is calculated;

[0071] i. Open the gate 5 to discharge the material in the hopper scale 4 to the feeding belt conveyor 6, close the gate 5 when the hopper scale 4 is discharged, and update the empty hopper scale value W 空 ;

[0072] j. Set the value of the coefficient a to correct the value of the stopping advance u, and the corrected stopping advance u is used as the stopping advance of the next time;

[0073] k. Repeat steps e-j until the total discharge reaches the predetermined value.

[0074] The present application avoids the problems of frequent setting and setting lag of the stopping advance of the operation personnel to adapt to the changes of the physical properties of the material, improves the accuracy of the blast furnace burdening circle number, makes the accuracy more than 98%, improves the central coke quantity, is beneficial to the control of the central airflow, and reduces the labor intensity of the operation personnel.

Claims

1. A method for precise control of the tapping of a blast furnace, characterized in that, The method comprises the following steps: a. installing a blast furnace under the discharge device: A feeder (2), a vibrating screen (3), a hopper scale (4) and a feeding belt conveyor (6) are sequentially installed below the discharge port at the bottom of the bin (1), and a gate (5) is installed at the bottom discharge port of the hopper scale (4); b. reading the empty hopper scale value W 空 , determining the hopper scale discharge setting value W 设 , calculating the full hopper scale value W 满 = W 设 + W 空 , setting the initial value of the stop material advance u; c. Start the feeder (2) and the vibrating screen (3) to deliver material to the hopper scale (4), and when the weight of the hopper scale (4) reaches W 满 , the feeder (2) and the vibrating screen (3) are stopped, and when the residual material on the vibrating screen (3) is discharged, the weight of the hopper scale (4) at this time is taken as the new full hopper weight W 满 , the gate (5) is opened to discharge the material in the hopper scale (4) to the feeding belt conveyor (6). d. After the hopper scale (4) is discharged, the gate (5) is closed, and the weighing value of the hopper scale (4) at this time is taken as a new empty hopper scale value W 空 ; e. Calculate the actual discharge value W of the hopper scale 实 : W 实 = W 满 - W 空 ; f. calculating the hopper scale discharge error E: E = W 实 - W 设 ; g. The hopper scale loading integrated set value W is calculated 综设 : W 综设 = W 设 - E + W 空 ; h.The feeder (2) and the vibrating screen (3) are started again to feed material into the hopper scale (4), and when the weighing value of the hopper scale (4) reaches W 综设 , the feeder (2) and the vibrating screen (3) are stopped, and the weighing value of the hopper scale (4) at this time is taken as the new full-hopper weighing value W 满 , and the hopper scale loading error e is calculated: e = W 满 - W 综设 ; i. open the gate (5) to discharge the material in the hopper scale (4) onto the feeding belt conveyor (6), and close the gate (5) after the hopper scale (4) is discharged, taking the weighing value of the hopper scale (4) at this time as the new empty hopper scale value W 空 ; j. correcting the value of the stop material advance u: setting the value of the coefficient a, adding the stop material advance u and ae to obtain a new stop material advance u; k. repeating steps e-j until the total discharge amount reaches the predetermined value.

2. The method for precise control of the discharge of a blast furnace according to claim 1, characterized in that, The value range of the stop material advance u is set as: u min ≤u≤u max wherein u min is the lower limit value of the stoppage advance amount, u max is the upper limit value of the stoppage advance amount, and when the value of the stoppage advance amount u is corrected, if the new stoppage advance amount u obtained is smaller than u min , the value of u is set to u min , and if the new stoppage advance amount u obtained is larger than u max , the value of u is set to u max .

3. The method for precise control of the discharge of a blast furnace according to claim 2, characterized in that, the upper limit value u of the stoppage advance amount max is set to W 设 × 10%, the lower limit value u of the stoppage advance amount min is set to -W 设 × 10%.

4. The method for precise control of the discharge of a blast furnace according to claim 3, characterized in that, The value range of the coefficient a is 0 < a < 1.

5. The method for precise control of the discharge of a blast furnace according to claim 4, characterized in that, The initial value of the stop material advance u is set as 0.

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