Mixture trough material level control method

Abstract

The invention discloses a mixture trough material level control method which comprises the following steps: S1, acquiring a current material level value, a material level value at a previous moment and a first duration; wherein the first duration is the time when the materials reach the mixing bin from the batching position; s2, the material level change speed is calculated according to the current material level value and the material level value at the previous moment; obtaining a predicted material level value according to the material level change speed, the first duration and the current material level value; s3, according to the current material level value and the predicted material level value, a preset material level state table is searched for to determine whether adjustment is needed or not; if yes, the step S4 is executed, and if not, the step S5 is executed; s4, determining an adjustment strategy and an adjustment amount, and adjusting the comprehensive feeding amount according to the adjustment strategy and the adjustment amount; and S5, the current comprehensive feeding amount is kept unchanged. Adjustment can be started in advance, and the problem that lag exists when the comprehensive feeding amount is increased or decreased through traditional arrangement of high and low material levels is solved.

Description

Technical Field

[0001] The invention relates to the technical field of sintering mixed material feeding, and in particular to a material level control method for a mixed material tank. Background Art

[0002] The mixing trough is a buffer trough before the sintering mixed raw materials enter the sintering machine trolley. It is installed at the head of the sintering machine as a buffer feeding device for distributing materials to the sintering machine. The mixed material is transported to the entrance of the mixing trough by a belt conveyor, and then distributed into the mixing trough by a shuttle distributor. At the outlet of the mixing trough, the material is evenly distributed on the sintering machine trolley through round rollers and nine rollers. The unstable material level of the mixing trough will affect the continuity of sintering. When the material level is too high, it will affect the operation of the mixing system. When the material level is too low, it will affect the operation of the sintering machine, thereby affecting the output and quality. Maintaining a certain material level stability in the mixing trough is conducive to stable feeding to the sintering machine and stabilizing the entire sintering production. Therefore, it is very important to realize automatic control of the material level of the mixing trough.

[0003] How to achieve automatic and precise control of the material level in a mixing trough is one of the important issues to be solved urgently in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a mixing trough material level control method to solve the deficiencies in the prior art. It can start the adjustment in advance and avoid the problem of lag in the traditional setting of high and low material levels to trigger an increase or decrease in the comprehensive feeding amount.

[0005] The present invention provides a method for controlling the material level of a mixing tank, which comprises the following steps:

[0006] S1, obtaining the current material level value, the material level value at the previous moment and the first duration; wherein the first duration is the time it takes for the material to reach the mixing silo from the batching place;

[0007] S2, calculating the material level change speed according to the current material level value and the material level value at the previous moment; and obtaining the predicted material level value according to the material level change speed, the first time duration and the current material level value;

[0008] S3, according to the current material level value and the predicted material level value, search the preset material level status table to determine whether adjustment is required; if yes, execute step S4, if not, execute step S5;

[0009] S4, determining an adjustment strategy and an adjustment amount, and adjusting the comprehensive feeding amount according to the adjustment strategy and the adjustment amount;

[0010] S5, keep the current comprehensive feeding amount unchanged.

[0011] The material level control method for the mixing trough as described above, optionally, further includes: step S4, after adjusting the comprehensive feeding amount, maintaining the first time length, and then executing step S1.

[0012] The mixing tank material level control method as described above, wherein, optionally, after step S5 is completed, it further includes, after maintaining the second time length, executing step S1; wherein the second time length is 2-10 seconds.

[0013] In the mixing trough material level control method as described above, optionally, the material level status table includes at least two current material level intervals, at least two predicted material level intervals and a material level status corresponding to any current material level interval and any predicted material level interval; the material level status is searched according to the current material level interval corresponding to the current material level value and the predicted material level interval corresponding to the predicted material level value.

[0014] In the mixing tank material level control method as described above, optionally, in the material level status table, the number of current material level intervals and the number of predicted material level intervals are both five; the five current material level intervals cover the entire range of current material level values, and there is no intersection between any two current material level intervals; the five predicted material level intervals cover the entire range of predicted material level intervals, and there is no intersection between any two predicted material level intervals.

[0015] In the above-mentioned mixing tank material level control method, optionally, the five current material level intervals are, in order from low to high, the first current material level interval, the second current material level interval, the third current material level interval, the fourth current material level interval and the fifth current material level interval; wherein the third current material level interval is the optimal material level interval;

[0016] The five predicted material level intervals are, in order from low to high, the first predicted material level interval, the second predicted material level interval, the third predicted material level interval, the fourth predicted material level interval and the fifth predicted material level interval; among them, the third predicted material level interval is the best predicted material level interval.

[0017] In the above-mentioned mixing tank material level control method, optionally, the corresponding relationship between the material level state and the adjustment strategy and the adjustment amount is:

[0018] If the current material level value is in the first current material level interval and the predicted material level value is in the first predicted material level interval, the comprehensive loading amount is increased and the adjustment amount is the first value;

[0019] If the current material level value is in the second current material level interval and the predicted material level value is in the first predicted material level interval, the comprehensive loading amount is increased and the adjustment amount is the second value;

[0020] If the current material level value is in the third current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the first predicted material level interval, the current comprehensive loading amount is maintained;

[0021] If the current material level value is in the first current material level interval, the second current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the second predicted material level interval, the current comprehensive loading amount is maintained;

[0022] If the current material level value is in the third current material level interval, and the predicted material level value is in the second predicted material level interval, the current comprehensive loading amount is maintained, or the comprehensive loading amount is increased;

[0023] If the current material level value is in the first current material level interval, the third current material level interval or the fifth current material level interval, and the current material level value is in the third predicted material level interval, the current comprehensive loading amount is maintained;

[0024] If the current material level value is in the second current material level interval or the fourth current material level interval, and the predicted material level value is in the third current material level interval, the comprehensive loading amount is adjusted, and the adjustment amount is the third value;

[0025] If the current material level value is in the first current material level interval, the second current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the fourth predicted material level interval, the current comprehensive loading amount is maintained;

[0026] If the current material level value is in the third current material level interval, and the predicted material level value is in the fourth predicted material level interval, the current comprehensive loading amount is maintained or reduced;

[0027] If the current material level value is in the first current material level interval, the second current material level interval or the third current material level interval, and the predicted material level value is in the fifth predicted material level interval, the current comprehensive loading amount is maintained;

[0028] If the current material level value is in the fourth current material level interval, and the predicted material level value is in the fifth predicted material level interval, the comprehensive loading amount is reduced, and the adjustment amount is the fourth value;

[0029] If the current material level value is in the fifth current material level interval and the predicted material level value is in the fifth predicted material level interval, the comprehensive loading amount is reduced, and the adjustment amount is the fifth value.

[0030] The mixing trough material level control method as described above, wherein, optionally, if the current material level value is in the third current material level interval, and the predicted material level value is in the second predicted material level interval; determine whether the current material level value is less than the middle value of the third current material level interval; if so, increase the comprehensive loading amount, and the adjustment amount is the third value; if not, maintain the current comprehensive loading amount.

[0031] The mixing tank material level control method as described above, wherein, optionally, if the current material level value is in the third material level interval, and the predicted material level value is in the fourth predicted material level interval;

[0032] Determine whether the current material level value is greater than the middle value of the third current material level interval; if so, reduce the comprehensive feeding amount, and the adjustment amount is the third value.

[0033] In the above-mentioned mixing tank material level control method, optionally, in step S2, the calculation formula for calculating the predicted material level value according to the material level change speed, the first time duration and the current material level value is:

[0034] LI predict =LI current +LI △ *T;

[0035] Among them, LI predict To predict the material level value, LI current is the current material level value, LI △ is the material level change speed, and T is the first duration.

[0036] Compared with the prior art, the present invention uses the current material level value and the predicted material level value obtained according to the current material level change speed to control the comprehensive feeding amount, and can start the adjustment in advance, avoiding the hysteresis problem of the traditional setting of high and low material level triggers to increase or decrease the comprehensive feeding amount. Compared with the size of the fuzzy control threshold, the number of times the comprehensive feeding amount is adjusted can be reduced. Due to the division of the material level interval, all possible material level values ​​are covered. This embodiment can adapt to various situations and has a wide adjustment range. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a flow chart of the steps of the present invention;

[0038] Figure 2 It is a schematic diagram of a mixing tank and a sintering machine proposed by the present invention;

[0039] Figure 3 is a flow chart of the steps of the control procedure of the method proposed by the present invention;

[0040] Figure 4 It is a sintering process flow chart applied by the method proposed in the present invention.

[0041] Description of reference numerals:

[0042] 1- batching trough, 2- primary mixing mechanism, 3- secondary mixer, 4- shuttle distributor, 5- mixing trough, 6- sintering machine. DETAILED DESCRIPTION

[0043] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but should not be construed as limiting the present invention.

[0044] In view of the problems raised in the background technology, the material level control of the mixing tank currently has the following problems in combination with the operating habits of the on-site operators and the existing control methods:

[0045] 1. In actual production, operators mostly control the material level in the mixing tank by adjusting the sintering machine speed. This method is fast and effective. However, this method is a means of dealing with abnormal situations such as sintering machine shutdown and mixing system shutdown. It is not in line with the sintering process control logic if it is used as a conventional control strategy.

[0046] 2. According to the production requirements of the sintering process, the material level control of the mixing tank is achieved by adjusting the comprehensive feeding amount, that is, by adjusting the total amount of materials entering the mixing tank to match the sintering output of the sintering machine, but it takes about 15-20 minutes for the materials to be transported from the batching place to the mixing tank. According to the traditional setting of high and low material levels to trigger the increase or decrease of the comprehensive feeding amount, there is a lag problem;

[0047] 3. The fuzzy control theory is used to comprehensively consider the state of the material level and the speed of the material level change. It is also a common means to control the material level balance of the mixing trough. However, the size of the fuzzy control threshold is difficult to adapt to various situations. Although it can achieve the purpose of controlling the material level, it will cause frequent adjustments. The mixing trough mainly plays a buffering role. According to production experience, the number of adjustments to the comprehensive feeding amount should be reduced as much as possible without interruption or overflow.

[0048] In order to solve the above problems and achieve the purpose of realizing automatic and accurate control of the material level in the mixing tank, the present invention proposes the following embodiments to solve the problems.

[0049] Example 1

[0050] Please refer to Figure 1 This embodiment proposes a mixing tank material level control method, which includes the following steps:

[0051] S1, obtain the current material level value, the material level value at the previous moment and the first time length; wherein the first time length is the time it takes for the material to reach the mixing silo from the batching place; the current material level value is detected by the weighing material level sensor, that is, it is used to reflect the current material level. Specifically, the first time length can be calculated according to the material delivery speed, which is related to the speed at which the material reaches the mixing silo from the delivery place.

[0052] S2, calculating the material level change speed according to the current material level value and the material level value at the previous moment; and obtaining the predicted material level value according to the material level change speed, the first time duration and the current material level value.

[0053] In this step, the calculation formula for calculating the predicted material level value according to the material level change speed, the first time length and the current material level value is:

[0054] LI predict =LI current +LI △ *T;

[0055] Among them, LI predict To predict the material level value, LI current is the current material level value, LI △ It is the material level change speed, that is, the speed at which the material level rises or falls, and the unit is t / min, that is, the difference between the current material level value and the material level value one minute ago, and T is the first time length.

[0056] S3, according to the current material level value and the predicted material level value, search the preset material level status table to determine whether adjustment is required; if yes, execute step S4, if not, execute step S5;

[0057] In specific implementation, the material level status table contains at least two current material level intervals, at least two predicted material level intervals, and the material level status corresponding to any current material level interval and any predicted material level interval; the material level status is searched according to the current material level interval corresponding to the current material level value and the predicted material level interval corresponding to the predicted material level value.

[0058] In implementation, the number of current material level intervals and predicted material level intervals is different, the material level status table is also different, and the number of corresponding material level states is also different. Specifically, the more the current material level intervals and predicted material level intervals are divided, the more refined the control is, and when there are too many intervals, the more complicated the control strategy is. Generally speaking, the current material level intervals are divided into 3 to 9, and the predicted material level intervals are also divided into 3-9.

[0059] In some cases, due to the different emphasis on the current material level and the predicted material level, the number of current material level intervals may be set to be different from the number of predicted material level intervals. In the present invention, it is not required that the number of predicted material level intervals must be the same as the number of current material level intervals.

[0060] However, in a better implementation, the current material level and the predicted material level are set to be equal, that is, in the material level status table, the number of current material level intervals and the number of predicted material level intervals are both five; the five current material level intervals cover the entire range of the current material level value, and there is no intersection between any two current material level intervals; the five predicted material level intervals cover the entire range of the predicted material level intervals, and there is no intersection between any two predicted material level intervals.

[0061] Specifically, the five current material level intervals are, in order from low to high, the first current material level interval, the second current material level interval, the third current material level interval, the fourth current material level interval and the fifth current material level interval; wherein the third current material level interval is the best material level interval; the five predicted material level intervals are, in order from low to high, the first predicted material level interval, the second predicted material level interval, the third predicted material level interval, the fourth predicted material level interval and the fifth predicted material level interval; wherein the third predicted material level interval is the best predicted material level interval. Specifically, the material level division thresholds Level_HH, Level_H, Level_L and Level_LL can be set, and the material level can be divided into five intervals accordingly.

[0062] S4, determining an adjustment strategy and an adjustment amount, and adjusting the comprehensive feeding amount according to the adjustment strategy and the adjustment amount.

[0063] In specific implementation, the corresponding relationship between the material level status and the adjustment strategy and adjustment amount is:

[0064] If the current material level value is in the first current material level interval and the predicted material level value is in the first predicted material level interval, the comprehensive loading amount is increased and the adjustment amount is the first value, that is, Level_L-Level_LL;

[0065] If the current material level value is in the second current material level interval and the predicted material level value is in the first predicted material level interval, the comprehensive loading amount is increased and the adjustment amount is the second value, that is, LIcurrent-Level_LL-LI△*60;

[0066] If the current material level value is in the third current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the first predicted material level interval, the current comprehensive loading amount is maintained.

[0067] If the current material level value is in the first current material level interval, the second current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the second predicted material level interval, the current comprehensive loading amount is maintained;

[0068] If the current material level value is in the third current material level interval, and the predicted material level value is in the second predicted material level interval, maintain the current comprehensive loading amount, or increase the comprehensive loading amount; specifically, determine whether the current material level value is less than the middle value of the third current material level interval; if so, increase the comprehensive loading amount, and the adjustment amount is the third value, that is, -LI △ *60; If not, keep the current comprehensive loading quantity.

[0069] If the current material level value is in the first current material level interval, the third current material level interval or the fifth current material level interval, and the current material level value is in the third predicted material level interval, the current comprehensive loading amount is maintained;

[0070] If the current material level value is in the second current material level interval or the fourth current material level interval, and the predicted material level value is in the third current material level interval, adjust the comprehensive feeding amount, and the adjustment amount is the third value, that is, -LI △ *60;

[0071] If the current material level value is in the first current material level interval, the second current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the fourth predicted material level interval, the current comprehensive loading amount is maintained;

[0072] If the current material level value is in the third current material level interval, and the predicted material level value is in the fourth predicted material level interval, maintain the current comprehensive loading amount or reduce the comprehensive loading amount; specifically, determine whether the current material level value is greater than the middle value of the third current material level interval; if so, reduce the comprehensive loading amount, and the adjustment amount is the third value, that is, -LI △ *60.

[0073] If the current material level value is in the first current material level interval, the second current material level interval or the third current material level interval, and the predicted material level value is in the fifth predicted material level interval, the current comprehensive loading amount is maintained;

[0074] If the current material level value is in the fourth current material level interval, and the predicted material level value is in the fifth predicted material level interval, the comprehensive loading amount is reduced, and the adjustment amount is the fourth value, that is, LIcurrent-Level_H+LI △ *60;

[0075] If the current material level value is in the fifth current material level interval, and the predicted material level value is in the fifth predicted material level interval, the comprehensive loading amount is reduced, and the adjustment amount is the fifth value, that is, Level_HH-Level_H.

[0076] In a specific implementation, the first value, the second value, the third value, the fourth value and the fifth value may all be fixed values, or all be variables, or some may be fixed values ​​and some may be variables.

[0077] It also includes that after adjusting the comprehensive feeding amount, step S4 maintains the first time length, and then executes step S1. That is, since there is a certain distance between the adjustment position of the feeding amount and the trough, after the comprehensive feeding amount is adjusted, it will reach the trough after the first time length. Therefore, no adjustment is made within the first time length after the comprehensive feeding amount is adjusted. Repeat the above process after the first time length. It should be pointed out that in order to ensure the accuracy of the second monitoring, the data in the buffer is updated within the first time length after the comprehensive feeding amount is adjusted, but the calculation of the predicted material level value is not performed.

[0078] S5, keep the current comprehensive feeding amount unchanged.

[0079] The method further includes: after step S5 is completed, the second time period is maintained, and then step S1 is executed; wherein the second time period is 2-10 seconds. That is, the predicted material level value is calculated once every second time period. In order to obtain the corresponding material level change speed, the corresponding material level change speed can be calculated once every second time period.

[0080] The adjustment amount of the comprehensive feeding amount is calculated according to the material level change rate, which is recorded as WT and the unit is t / h. The setting value of the comprehensive feeding amount is read from the basic automation system, which is recorded as WQ and the unit is t / h. It is manually set by the operator. In the automatic control mode of the present invention, the system automatically calculates the adjustment amount of the comprehensive feeding amount, and WQ=WQ q +WT, to adjust the comprehensive feeding amount, where WQ q This is the comprehensive material loading quantity before this adjustment.

[0081] Specifically, taking the second time length of 5 seconds as an example, every five seconds, the current material level is read in the material level data buffer Buffer_Lev, and the data buffer length is 12, that is, the data buffer can store data of 12 material levels. Then,

[0082] LI △ = Buffer_Lev

[11] -Buffer_Lev[0], when the material level is on an upward trend, LI△>0, when the material level is on a downward trend, LI △ <0;

[0083] LI current =Buffer_Lev

[11]

[0084] WT=LI △ *60+WT △ , WT △ In order to ensure that the final material level is stable in the optimal current material level range, the amount of adjustment is made based on the specific situation to ensure the balance, so that the material level moves to the optimal current material level range. Different material level states WT △ The value of is different; where WT is the adjustment amount of the comprehensive loading amount.

[0085] When the second duration is 2 seconds, the buffer length should be 30, corresponding to LI △ = Buffer_Lev

[29] -Buffer_Lev[0], that is, the time length corresponding to the buffer length is 1 minute, LI △ is the difference between the current material level and the material level in 1 minute. When the second time length is 6 seconds, the buffer length should be 10.

[0086] Specifically, when writing the control program, you can refer to Figure 3 .

[0087] Through the above steps, the comprehensive feeding amount is controlled by using the current material level value and the predicted material level value obtained according to the current material level change speed, and the adjustment can be started in advance, avoiding the hysteresis problem of the traditional setting of high and low material level triggers to increase or decrease the comprehensive feeding amount. Compared with the size of the fuzzy control threshold, the number of times the comprehensive feeding amount is adjusted can be reduced. Since the division of the material level interval covers all possible material level values, this embodiment can adapt to various situations and has a wide adjustment range.

[0088] The principle of this embodiment is:

[0089] Please refer to this embodiment, which proposes a control method that uses the current material level of the mixing tank and the predicted material level to achieve the control of the material level of the mixing tank. The combination of the current material level and the predicted material level is equivalent to using a material level interval instead of using only one material point as a condition to trigger the adjustment, such as Figure 2 As shown, at any time, the current material level status only includes three possibilities: rising, stable and falling. When the material level is in a downward trend, the upper end of the "material level interval" in the figure indicates the current material level, and the lower end indicates the predicted material level; similarly, when the material level is in an upward trend, the lower end of the "material level interval" indicates the current material level, and the upper end indicates the predicted material level. Through the above division, combined with the actual production division of high and low material levels, it is possible to adjust the feeding amount in advance and adjust it according to the actual production requirements, avoiding frequent adjustment of the feeding amount, thereby ensuring that the material level is stable within a certain range.

[0090] Example 2

[0091] This embodiment is proposed on the basis of the embodiment 1, and the similarities are not repeated here. The following is a further description of the material level status table.

[0092] In this embodiment, the material level interval is divided into five intervals as an example, and the current material level value and the predicted material level value share the five material level intervals. In other words, it is equivalent to the first current material level interval in Example 1 being the same as the first predicted material level interval, the second current material level interval being the same as the second predicted material level interval, the third current material level interval being the same as the third predicted material level interval, the fourth current material level interval being the same as the fourth predicted material level interval, and the fifth current material level interval being the same as the fifth predicted material level interval.

[0093] In this embodiment, the material level division thresholds Level_LL, Level_L, Level_H, and Level_HH are set, and the thresholds are used as critical points to divide the material levels into the first material level interval, the second material level interval, the third material level interval, the fourth material level interval, and the fifth material level interval in order from low to high.

[0094] According to the above classification, the material level status table is shown in Table 1.

[0095] Table 1 Material level status table

[0096]

[0097] In the above table, different numbers represent different material level states. Through analysis, we can derive the specific working conditions of each state, that is, one of the following: material level increase, material level decrease, and material level stability. The specific state analysis and adjustment strategies are as follows:

[0098] State 1 means that both the current material level and the predicted material level are in the first material level interval. The material level is judged to be in the first material level interval and is in a stable state. According to production operation experience, although the current material level is stable, it is in the first material level interval state, so the comprehensive feeding amount is increased, and the adjustment amount is Level_L-Level_LL.

[0099] State 2 means that the current material level is in the second material level interval, the predicted material level is in the first material level interval, the material level is in a decreasing state, the comprehensive feeding amount is increased, and the adjustment amount is LI current -Level_LL-LI △ *60;

[0100] In states 3, 4, and 5, the predicted material level is in the first material level interval, and the material level is on a downward trend, so no adjustment is made;

[0101] State 6 means that the current material level is in the first material level interval, the predicted material level is in the first material level interval, the material level is increasing, and no adjustment is made;

[0102] State 7 means that the current material level is in the second material level interval, the predicted material level is in the second material level interval, the material level is in a stable state, and no adjustment is made;

[0103] State 8 means that the current material level is in the third material level interval, and the predicted material level is in the second material level interval. This state is distinguished by whether the current material level is less than the optimal material level Level_OK (Level_OK = Level_L + (Level_H - Level_L) / 2). If the current material level LIcurrent is in the (Level_L, Level_OK] interval, the comprehensive feeding amount is increased, and the adjustment amount is -LI △ *60;

[0104] Status 9 and 10 indicate that the predicted material level is in the second material level interval, the material level is on a downward trend, and no adjustment is made;

[0105] State 11 means that the current material level is in the first material level interval, the predicted material level is in the third material level interval, the material level is increasing, and no processing is performed;

[0106] State 12 means that the current material level is in the second material level interval, and the predicted material level is in the third material level interval. The material level is increasing, and the feeding amount is reduced. The adjustment amount is -LI△*60;

[0107] State 13 means that the current material level is in the third material level interval, and the predicted material level is also in the third material level interval. It is considered that the material level is relatively stable and no processing is performed;

[0108] State 14 means that the current material level is in the fourth material level interval, and the predicted material level is in the third material level interval. The material level is decreasing, and the feeding amount is increased, and the adjustment amount is -LI△*60;

[0109] State 15 means that the current material level is in the fifth material level interval, the predicted material level is in the third material level interval, the material level is decreasing, and no processing is performed;

[0110] Status 16 and 17 indicate that the current state is in the second material level interval or the first material level interval, the material level is rising, and no processing is performed;

[0111] State 18 indicates that the current material level is in the third material level interval, and the predicted material level is in the fourth material level interval. This state is distinguished by whether the current material level is greater than the optimal material level Level_OK (Level_OK = Level_L + (Level_H - Level_L) / 2). If the current material level LI is satisfied current In the (Level_OK, Level_H] range, the comprehensive feeding amount is reduced, and the adjustment amount is -LI △ *60;

[0112] Status 19 and 20 indicate that the current material level is in the fifth material level interval or the fourth material level interval, and the material level is in a decreasing or stable state, and no processing is performed;

[0113] States 21, 22 and 23 indicate that the predicted material level is in the fifth material level interval, the material level is rising, and no processing is performed;

[0114] State 24 means that the current material level is in the fourth material level interval, the material level is rising, and the comprehensive feeding amount is reduced. The adjustment amount is LI current -Level_H+LI △ *60;

[0115] State 25 means that the current material level and the predicted material level are both in the fifth material level interval. The material level is relatively stable, but in the HH interval. Reduce the feeding amount, and the adjustment amount is Level_HH-Level_H.

[0116] According to the above control logic, the system obtains the material level data of the mixing silo every 5 seconds, calculates the current material level and the predicted material level, and calculates the adjustment amount of the comprehensive feeding amount according to the status of the current material level and the predicted material level. Each adjustment is delayed and waited for the first time period T before another judgment and adjustment can be made. The first time period T is the time it takes for the material to reach the mixing silo from the batching point. This cycle is repeated to achieve automatic control of the material level in the mixing trough.

[0117] It should be noted that the symbols in this embodiment have the same meanings as those in Embodiment 1. They will not be repeated here.

[0118] In order to facilitate the implementation of the above embodiments 1 and 2, the structure of the mixing tank used in the entire sintering process is introduced below.

[0119] Please refer to Figure 4 In the whole sintering process, the batching ore trough 1, the primary mixing mechanism 2, the secondary mixer 3, the shuttle distributor 4, the mixing trough 5 and the sintering machine 6 are included in sequence.

[0120] The material passes through the primary mixer 2, the secondary mixer 3, and the shuttle distributor 4 from the batching trough 1, and then enters the mixing trough 5. After passing through the mixing trough 5, it is placed on the sintering machine 6.

[0121] It should be pointed out that, in the present invention, the material level change speed refers to a direction, that is, positive means upward, and the material level has an increasing trend, and negative means downward, and the material level has a decreasing trend.

[0122] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the drawings. Any changes made according to the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the protection scope of the present invention.

Claims

1. A method for controlling the material level of a mixing tank, Features: The following steps are included: S1, obtaining the current material level value, the material level value at the previous moment and the first duration; wherein the first duration is the time it takes for the material to reach the mixing silo from the batching place; S2, calculating the material level change speed according to the current material level value and the material level value at the previous moment; and obtaining the predicted material level value according to the material level change speed, the first time duration and the current material level value; S3, according to the current material level value and the predicted material level value, search the preset material level status table to determine whether adjustment is required; if yes, execute step S4, if not, execute step S5; S4, determining an adjustment strategy and an adjustment amount, and adjusting the comprehensive feeding amount according to the adjustment strategy and the adjustment amount; S5, keep the current comprehensive feeding amount unchanged.

2. The mixing tank material level control method according to claim 1, Features: The method further includes: after adjusting the comprehensive feeding amount, step S4 maintains the first time length and then executes step S1.

3. The mixing tank material level control method according to claim 2, Features: After step S5 is completed, the method further includes: after maintaining the second time length, executing step S1; wherein the second time length is 2-10 seconds.

4. The mixing tank material level control method according to claim 3, Features: The material level status table includes at least two current material level intervals, at least two predicted material level intervals, and the material level status corresponding to any current material level interval and any predicted material level interval; the material level status is searched according to the current material level interval corresponding to the current material level value and the predicted material level interval corresponding to the predicted material level value.

5. The mixing tank material level control method according to claim 4, Features: In the material level status table, the number of current material level intervals and the number of predicted material level intervals are both five; the five current material level intervals cover the entire range of current material level values, and there is no intersection between any two current material level intervals; the five predicted material level intervals cover the entire range of predicted material level intervals, and there is no intersection between any two predicted material level intervals.

6. The mixing tank material level control method according to claim 5, Features: The five current material level intervals are, in order from low to high, the first current material level interval, the second current material level interval, the third current material level interval, the fourth current material level interval and the fifth current material level interval; among which, the third current material level interval is the optimal material level interval; The five predicted material level intervals are, in order from low to high, the first predicted material level interval, the second predicted material level interval, the third predicted material level interval, the fourth predicted material level interval and the fifth predicted material level interval; among them, the third predicted material level interval is the best predicted material level interval.

7. The mixing tank material level control method according to claim 6, Features: The corresponding relationship between material level status, adjustment strategy and adjustment amount is: If the current material level value is in the first current material level interval and the predicted material level value is in the first predicted material level interval, the comprehensive loading amount is increased and the adjustment amount is the first value; If the current material level value is in the second current material level interval and the predicted material level value is in the first predicted material level interval, the comprehensive loading amount is increased and the adjustment amount is the second value; If the current material level value is in the third current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the first predicted material level interval, the current comprehensive loading amount is maintained; If the current material level value is in the first current material level interval, the second current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the second predicted material level interval, the current comprehensive loading amount is maintained; If the current material level value is in the third current material level interval, and the predicted material level value is in the second predicted material level interval, the current comprehensive loading amount is maintained, or the comprehensive loading amount is increased; If the current material level value is in the first current material level interval, the third current material level interval or the fifth current material level interval, and the current material level value is in the third predicted material level interval, the current comprehensive loading amount is maintained; If the current material level value is in the second current material level interval or the fourth current material level interval, and the predicted material level value is in the third current material level interval, the comprehensive loading amount is adjusted, and the adjustment amount is the third value; If the current material level value is in the first current material level interval, the second current material level interval, the fourth current material level interval or the fifth current material level interval, and the predicted material level value is in the fourth predicted material level interval, the current comprehensive loading amount is maintained; If the current material level value is in the third current material level interval, and the predicted material level value is in the fourth predicted material level interval, the current comprehensive loading amount is maintained or reduced; If the current material level value is in the first current material level interval, the second current material level interval or the third current material level interval, and the predicted material level value is in the fifth predicted material level interval, the current comprehensive loading amount is maintained; If the current material level value is in the fourth current material level interval, and the predicted material level value is in the fifth predicted material level interval, the comprehensive loading amount is reduced, and the adjustment amount is the fourth value; If the current material level value is in the fifth current material level interval, and the predicted material level value is in the fifth predicted material level interval, the comprehensive loading amount is reduced, and the adjustment amount is the fifth value.

8. The mixing tank material level control method according to claim 7, Features: If the current material level value is in the third current material level interval, and the predicted material level value is in the second predicted material level interval; determine whether the current material level value is less than the middle value of the third current material level interval; If yes, increase the comprehensive feeding amount, and the adjustment amount is the third value; if no, keep the current comprehensive feeding amount.

9. The mixing tank material level control method according to claim 7, Features: If the current material level value is in the third material level interval, and the predicted material level value is in the fourth predicted material level interval; Determine whether the current material level value is greater than the middle value of the third current material level interval; if so, reduce the comprehensive feeding amount, and the adjustment amount is the third value.

10. The mixing tank material level control method according to any one of claims 1 to 9, Features: In step S2, the calculation formula for calculating the predicted material level value according to the material level change speed, the first time duration and the current material level value is: LI predict =LI current +LI △ *T; Among them, LI predict To predict the material level value, LI current is the current material level value, LI △ is the material level change speed, and T is the first time duration.

Images