Intelligent control method for granulating by ammonia-acid method

Abstract

The invention relates to an ammonia-acid method granulation intelligent control method, which is based on a DCS (Distributed Control System) and according to real-time given value data, medium flow is subjected to low-frequency regulation through a regulating valve, so that the medium flow is close to a given value, automatic control of a loop is achieved, and automatic control of granulation is further realized. Wherein the real-time given value data is calculated on the basis of reference data of an acquisition loop and the feeding amount, the returning amount and the material moisture content which are acquired in real time in combination with a preset proportionality coefficient and a moisture adjustment coefficient; the specific calculation formula is as follows: SV = (M input * x / Q water + M return * x / Q water) * M total * y * A water (formula I); in the formula, SV is a given value outside a real-time calculation loop; m is the mean value of the feeding amount; m < return > is a return amount mean value; m < total > is the total material amount; x is a proportionality coefficient; y is a moisture adjustment coefficient; water A is the moisture content of the material; q water is primary water flow. The system has the advantages that the manual addition of saturated steam, primary water, concentrated sulfuric acid and liquid ammonia medium in the granulation process of the traditional double-drying double-cooling roller process is changed into DCS (Distributed Control System) automatic control; under the introduction of a material quantity mean value concept, the accuracy of basic parameters is ensured by combining feeding data comparison and timely correction, and then the automatic control adding of a medium is realized based on a self-adjusting loop, so that the stable and efficient operation of a granulation working section is realized.

Description

Technical Field

[0001] The invention relates to the field of preparation of amino acid-based compound fertilizers, and in particular to an intelligent control method for amino acid-based granulation. Background Art

[0002] In the process of compound fertilizer preparation, the commonly used compound fertilizer granulation method is the amino acid granulation method, which is to produce compound fertilizer in the granulator under the atmosphere of ammonia in the gas based on monoammonium phosphate, urea and potassium sulfate powder. In the granulation process, the three nutrient raw materials of nitrogen, phosphorus and potassium enter the granulation area in the form of powder materials (usually urea, monoammonium phosphate, potassium chloride and additives, etc.), concentrated sulfuric acid and water are diluted in a certain proportion in the acid mixer, and the diluted sulfuric acid enters the granulation bed layer, and reacts with the liquid ammonia transported to the bed layer at the same time to generate ammonium sulfate with a higher temperature. The powder material and the ammonium sulfate slurry form a solid solution of a certain liquid phase, which rolls into granules in the drum granulator; at the same time, monoammonium phosphate reacts with excess ammonia, and the molten solution of ammonium phosphate itself is used to bond other materials, and then the liquid phase of the material is controlled by saturated steam and primary water to granulate into balls; the granulator needs to control the appropriate temperature (55-75℃) and pH environment, the temperature in the granulator is provided by saturated steam, and the insufficient liquid phase is supplemented by primary water. In the above process, saturated steam, primary water, concentrated sulfuric acid, liquid ammonia and other media are quantitatively added by the operator according to the time to ensure the granulation effect. Generally, in the drum granulation process, the ball formation rate of the granulation process is about 60%, and the unqualified particle size materials are returned to the granulator after screening and crushing.

[0003] Since the drum granulation process has the control characteristics of "long control delay, dry rather than wet, low adjustment frequency", currently all granulation is carried out by manual addition, which is prone to the following problems: 1. The amount of each medium added cannot be changed in time with the change of machine time, resulting in poor intermittent granulation effect and low finished product output rate; 2. Personnel need to stay at one end of the granulation drum for 24 hours to monitor and adjust the feed amount. The on-site operating environment is harsh and the working environment of personnel is poor. 3. Since it takes 3-5 minutes for the raw materials to enter the granulator after the data measurement is generated, it is a large lag control loop, and conventional PID control technology cannot achieve automatic control at all; 4. The metering belt data fluctuates up and down within a small range, and there are intermittent abnormal conditions such as scale breakage and large fluctuations in return flow. Once the control result is calculated incorrectly, it will cause uneven dryness and wetness of the material in the granulator and poor granulation effect. 5. Due to the large number of granulation formulas and the large difference in the amount of reaction medium added, it is impossible to quantify the empirical data; at the same time, the effect verification after granulation has not been quantified;

[0004] In summary, how to achieve automatic granulation in the double-drying and double-cooling drum process and stable and efficient operation of the granulation section has become a problem that the device needs to tackle for a long time and needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an intelligent control method for amino acid granulation, which changes the addition of saturated steam, primary water, concentrated sulfuric acid and liquid ammonia media in the traditional double-drying and double-cooling drum process granulation process from manual addition to DCS automatic control; under the introduction of the concept of material quantity mean, combined with the data comparison of the feed, timely correction is made to ensure the accuracy of the basic parameters, and then the automatic control addition of the medium is realized based on the self-adjusting loop, so that the granulation section can operate stably and efficiently.

[0006] The present invention is achieved through the following technical solutions: On the one hand, a method for intelligent control of amino acid granulation is provided, which is based on a DCS control system, according to real-time given value data, and uses a regulating valve to perform low-frequency regulation on the medium flow rate so that it approaches the given value, thereby achieving automatic control of the loop and further realizing automatic control of granulation;

[0007] The real-time given value data is calculated based on the reference data of the acquisition circuit and the real-time collected feed amount, return amount and moisture content of the material, combined with the preset proportional coefficient and moisture adjustment coefficient; the specific calculation formula is as follows:

[0008] SV=(M 投 *x / Q 水 +M 返 *x / Q 水 )*M 总 *y*A 水 (Formula I);

[0009] Where, SV: real-time calculation of the given value outside the loop; M 投 : average feeding amount; M 返 : Mean value of returned material; M 总 : Total amount of material; X: Proportional coefficient; Y: Moisture adjustment coefficient; A 水 : Moisture content of materials; Q 水 : Primary water flow.

[0010] Furthermore, the benchmark data includes collected flow data, feeding data and return data; and the calculation formula is obtained as follows:

[0011] Step 1: Collect baseline quantities

[0012] At the moment when the corresponding self-regulating loop switches to the automatic mode, the feed amount, return amount and material moisture content are collected in real time, and the steam flow rate, the average feed amount and the average return amount are used as the reference control data; and the unit feed steam amount is calculated by the following formula;

[0013] Unit feed steam quantity = Q 蒸汽 / (feeding amount + return amount)*proportional coefficient (Formula II);

[0014] Step 2: Calculate the unit return steam volume

[0015] Feed steam volume = unit feed steam volume * feed volume

[0016] Unit return steam volume = (Q 流量 - Feed steam amount) / return amount (Formula III);

[0017] Step 3: Take the unit feed steam volume and unit return steam volume as the control parameter basis, and calculate the real-time SV value based on the transformation of feed volume and return volume.

[0018] SV = (unit feed steam volume * average feed volume + unit return steam volume * average return volume) * moisture analysis data * moisture adjustment coefficient (Formula IV).

[0019] Furthermore, the loop is selected from any one of a primary water self-regulating loop, a concentrated sulfuric acid self-regulating loop, a steam self-regulating loop, and a liquid ammonia self-regulating loop, and each control loop forms a closed-loop negative feedback control loop.

[0020] Furthermore, the primary water self-regulating circuit is interlocked with the concentrated sulfuric acid self-regulating circuit, and the primary water and concentrated sulfuric acid are mixed to prepare acid based on feed amount and concentration value.

[0021] Furthermore, the control process of the primary water self-adjusting loop is as follows: the average value is calculated according to the feed amount and return amount of the drum production line according to the time length, and then the benchmark data of the control loop is automatically collected at the moment of switching between manual / automatic modes, and then the unit primary water consumption is automatically calculated, and then the real-time given value data is calculated based on the unit primary water consumption combined with the average return amount, the average feed amount and the moisture content of the material at the outlet of the online quantitative granulator, and the frequency of the primary water pump is adjusted at a low frequency to make it close to the given value, so as to realize automatic control of the loop.

[0022] Furthermore, the control process of the concentrated sulfuric acid self-adjusting loop is as follows: the average value is calculated according to the feed amount and return amount of the drum production line according to the time length, and then the reference data of the control loop is automatically collected at the moment of switching between manual / automatic modes, and the unit sulfuric acid dosage is automatically calculated, and then the real-time given value data is calculated based on the unit sulfuric acid dosage combined with the average return amount, the average feed amount and the moisture content of the material at the outlet of the online quantitative granulator, and the frequency of the sulfuric acid pump is adjusted at a low frequency to make it approach the given value, thereby finally realizing automatic control of the loop.

[0023] Furthermore, the control process of the steam self-regulating loop is: first, the instantaneous baseline data of the automatic mode is obtained, and then the unit steam consumption is automatically calculated. Then, according to the unit steam consumption combined with the average return amount, the average feed amount and the moisture content of the material on the online quantitative aging belt, the real-time given value data is calculated, and the steam regulating valve is adjusted at a low frequency to make it approach the given value, thereby finally realizing automatic control of the loop.

[0024] Furthermore, the control process of the liquid ammonia self-regulating loop is: automatically collecting the benchmark data at the moment of manual / automatic mode switching of each control loop, and then automatically calculating the unit liquid ammonia dosage, and then calculating the real-time given value data based on the unit liquid ammonia dosage combined with the average return material amount, the average feed amount and the moisture content of the material on the online quantitative aging belt, and adjusting the frequency of the liquid ammonia pump at a low frequency to make it close to the given value, so as to finally realize automatic control of the loop.

[0025] Furthermore, the feed amount and the return amount are both measured by a metering belt; and the moisture content of the material is measured in real time by an online moisture analyzer.

[0026] Preferably, the addition amount of saturated steam, primary water, concentrated sulfuric acid and liquid ammonia medium in the reaction medium is based on the material amount mean to achieve comparison and correction of the feeding data; the material amount mean refers to the average value calculated based on the feeding amount and return amount of the drum production line according to the time length.

[0027] Beneficial Effects

[0028] The invention changes the addition of saturated steam, primary water, concentrated sulfuric acid and liquid ammonia media in the traditional double-drying and double-cooling drum process granulation process from manual addition to DCS automatic control, and realizes automatic control of the drum granulation material through the control of the medium addition self-adjusting loop, thereby realizing intelligent control of the drum granulation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the present invention;

[0030] Figure 2 It is a pipeline arrangement diagram of four regulating loops embodied in the present invention;

[0031] Figure 3 It is a schematic diagram of the automatic granulation operation interface;

[0032] Figure 4 It is a pipeline arrangement diagram of a liquid ammonia regulating loop embodied in the present invention;

[0033] Figure 5 It is a pipeline arrangement diagram of a steam regulating loop embodied in the present invention.

[0034] 1. Primary water self-regulating circuit; 2. Concentrated sulfuric acid self-regulating circuit; 3. Steam self-regulating circuit; 4. Liquid ammonia self-regulating circuit; 5. Granulator; 6. DCS input control system; 7. Material metering. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The experimental methods without specific conditions in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, all percentages, ratios, proportions or parts are by weight.

[0037] Unless otherwise specified, the reagents and raw materials used in the examples and comparative examples of the present invention can be obtained through commercial channels.

[0038] Example 1

[0039] A method for intelligent control of amino acid granulation, which is based on a DCS control system, and adjusts the medium flow rate through a regulating valve at a low frequency according to real-time given value data to make it approach a given value, thereby achieving automatic control of the loop, and further realizing automatic control of granulation; wherein the real-time given value data is calculated based on the reference data of the acquisition loop and the real-time collected feed amount, return amount and moisture content of the material, combined with a preset proportional coefficient and a moisture adjustment coefficient; the specific calculation formula is as follows:

[0040] SV = (M input * x / Q water + M return * x / Q water) * M total * y * A water (Formula I);

[0041] In the formula, SV: given value outside the real-time calculation loop; Mput: average feed amount; Mreturn: average return amount; Mtotal: total material amount; X: proportional coefficient; Y: moisture adjustment coefficient; Awater: moisture content of material; Qwater: primary water flow rate.

[0042] Based on the above scheme, the benchmark data includes the collected flow data, feeding data and return data; and the acquisition process of the above calculation formula is as follows:

[0043] Step 1: Collect baseline quantities

[0044] At the moment when the corresponding self-regulating loop switches to the automatic mode, the feed amount, return amount and material moisture content are collected in real time, and the steam flow rate, the average feed amount and the average return amount are used as the reference control data; and the unit feed steam amount is calculated by the following formula;

[0045] Unit feed steam quantity = Q 蒸汽 / (feeding amount + return amount)*proportional coefficient (Formula II);

[0046] Step 2: Calculate the unit return steam volume

[0047] Feed steam volume = unit feed steam volume * feed volume

[0048] Unit return steam volume = (Q 流量 - Feed steam amount) / return amount (Formula III);

[0049] Step 3: Take the unit feed steam volume and unit return steam volume as the control parameter basis, and calculate the real-time SV value based on the transformation of feed volume and return volume.

[0050] SV = (unit feed steam volume * average feed volume + unit return steam volume * average return volume) * moisture analysis data * moisture adjustment coefficient (Formula IV).

[0051] On the basis of the above scheme, the addition amount of saturated steam, primary water, concentrated sulfuric acid, and liquid ammonia medium in the reaction medium is based on the material amount mean to achieve the comparison and correction of the feeding data; the material amount mean refers to the average value calculated based on the feeding amount and the return amount of the drum production line according to the time length. The addition amount of saturated steam, primary water, concentrated sulfuric acid, and liquid ammonia medium of the present invention is added according to the basic parameters of the feeding scale of the powdered material. In order to achieve the accurate addition of the above medium, the concept of the material amount mean is introduced in the design of the self-adjusting circuit, the instantaneous correction value of each feeding scale is increased, and the data comparison is timely corrected according to the feeding data comparison during the production process to ensure that the data collected by the control circuit is accurate. At the same time, a primary water self-adjusting circuit 1, a concentrated sulfuric acid self-adjusting circuit 2, a steam self-adjusting circuit 3, and a liquid ammonia self-adjusting circuit 4 are designed in the drum device. Through the ingenious design and operation mode design of the above self-adjusting circuit, the original manual feeding method of the granulation process is changed to realize DCS automatic control. The control scheme includes a primary water self-adjusting circuit 1 and a concentrated sulfuric acid self-adjusting circuit 2 to be interlocked, and the concentrated sulfuric acid is allowed to be put into operation and adjusted after the water flow is detected first.

[0052] Among them, the specific components of the four regulating loops are: flow meter, regulating valve (frequency converter) and DCS control system, among which the flow meter is used as the control basis and standard, the regulating valve (frequency converter) is the actuator to adjust the opening of the field regulating valve (the frequency of the frequency converter), and the DCS input control system 6 realizes the calculation of the field control data, which is then executed by the regulating valve (frequency converter), and finally forms a closed-loop negative feedback control loop.

[0053] Data collection process: At the moment of switching from manual to automatic mode of each control loop, the collected flow data, feeding data and return data are sent to the DCS input control system as reference data. For example, if the primary water flow data is 140m3 / h and the average feeding data is 20T, the unit water demand is 140 / 20=7m3 / h. Then, according to the subsequent collected average feeding amount, if the average feeding amount in the next cycle is 22 tons, the given value required for the primary water loop is 154m3 / h, and then the frequency of the inverter is changed to make the measured value and the given value the same. The principles of the other three loops are basically the same.

[0054] In the above technical solution, the loop is selected from any one of a primary water self-regulating loop, a concentrated sulfuric acid self-regulating loop, a steam self-regulating loop, and a liquid ammonia self-regulating loop, and each control loop is a closed-loop negative feedback control loop.

[0055] In the above technical solution, the primary water self-adjusting circuit is interlocked with the concentrated sulfuric acid self-adjusting circuit, and the primary water and concentrated sulfuric acid are mixed to prepare the acid based on the feed amount and concentration value.

[0056] In the above technical scheme, the control process of the primary water self-adjusting loop is: according to the feed amount and return amount of the drum production line, the average value is calculated according to the time length, and then the benchmark data of the control loop is automatically collected at the moment of switching between manual / automatic modes, and then the unit primary water consumption is automatically calculated, and then the real-time given value data is calculated based on the unit primary water consumption combined with the average return amount, the average feed amount and the moisture content of the material at the outlet of the online quantitative granulator, and the frequency of the primary water pump is adjusted at a low frequency to make it close to the given value, so as to realize automatic control of the loop.

[0057] In the above technical scheme, the control process of the concentrated sulfuric acid self-adjusting loop is: according to the feed amount and return amount of the drum production line, the average value is calculated according to the time length, and then the reference data of the control loop is automatically collected at the moment of switching between manual / automatic modes, and then the unit sulfuric acid dosage is automatically calculated, and then the real-time given value data is calculated based on the unit sulfuric acid dosage combined with the average return amount, the average feed amount and the moisture content of the material at the outlet of the online quantitative granulator 5, and the frequency of the sulfuric acid pump is adjusted at a low frequency to make it close to the given value, so as to finally realize automatic control of the loop.

[0058] In the above technical scheme, the control process of the steam self-regulating loop is: first, the baseline data of the automatic mode is obtained, and then the unit steam consumption is automatically calculated. Then, according to the unit steam consumption combined with the average return amount, the average feed amount and the moisture content of the material on the online quantitative aging belt, the real-time given value data is calculated, and the steam regulating valve is adjusted at a low frequency to make it approach the given value, thereby realizing automatic control of the loop.

[0059] In the above technical scheme, the control process of the liquid ammonia self-regulating loop is: automatically collect the benchmark data at the moment of manual / automatic mode switching of each control loop, and then automatically calculate the unit liquid ammonia consumption, and then calculate the real-time given value data based on the unit liquid ammonia consumption combined with the average return material amount, the average feed amount and the moisture content of the material on the online quantitative aging belt, and adjust the frequency of the liquid ammonia pump at a low frequency to make it close to the given value, so as to finally realize automatic control of the loop.

[0060] In the above technical solution, both the feeding amount and the returning amount are measured by the metering belt 7; the moisture content of the material is measured in real time by the online moisture analyzer.

[0061] The specific process of realizing the self-adjusting circuit of the above-mentioned medium is as follows: primary water flow control of the primary water self-adjusting circuit 1: calculate the average value according to the feeding amount and return amount of the drum production line according to the time length, and then automatically collect the benchmark data of the control loop (primary water flow, return amount average, feeding amount average) at the moment of switching between manual / automatic modes, and then automatically calculate the unit primary water consumption of feeding (returning), and then calculate the real-time given value data based on the unit primary water consumption combined with the return amount average, the feeding amount average and the moisture content of the material at the outlet of the online quantitative granulator, and adjust the frequency of the primary water pump at a low frequency to make it close to the given value, so as to finally realize automatic control of the circuit.

[0062] Sulfuric acid flow control of concentrated sulfuric acid self-adjusting loop 2: calculate the average value according to the feed amount and return amount of the drum production line according to the time length, and then automatically collect the benchmark data of the control loop (sulfuric acid flow, return amount average, feed amount average) at the moment of switching between manual and automatic modes, and then automatically calculate the unit sulfuric acid dosage of the feed (return), and then calculate the real-time given value data based on the unit sulfuric acid dosage combined with the return amount average, the feed amount average and the moisture content of the material at the outlet of the online quantitative granulator, and adjust the frequency of the sulfuric acid pump at a low frequency to make it close to the given value, so as to finally realize automatic control of the loop.

[0063] The steam self-regulating loop 3 refers to the automatic addition of saturated steam, calculating the average value according to the feed amount and return amount of the drum production line according to the time length, and then automatically collecting the benchmark data (steam flow, return amount, feed amount) of the control loop at the moment of switching between manual / automatic modes, and then calculating the unit steam consumption of the feed (return), and then according to the unit steam consumption, combined with the average return amount, the average feed amount and the moisture content of the material on the online quantitative aging belt, calculate the real-time given value data, adjust the steam regulating valve to make it close to the given value, and finally realize the automatic control of the loop.

[0064] Liquid ammonia flow control of liquid ammonia self-regulating loop 4: calculate the average value according to the feed amount and return amount of the drum production line according to the time length, and then automatically collect the benchmark data of the control loop (liquid ammonia flow, return amount average, feed amount average) at the moment of switching between manual and automatic modes, and then automatically calculate the unit liquid ammonia dosage of the feed (return), and then calculate the real-time given value data based on the unit liquid ammonia dosage combined with the return amount average, the feed amount average and the moisture content of the material on the online quantitative aging belt, and adjust the opening of the liquid ammonia regulating valve at a low frequency to make it close to the given value, so as to finally realize automatic control of the loop.

[0065] On the basis of the above scheme, the system control adjustment proportional coefficient and the moisture adjustment coefficient are set in advance according to experience to guide automatic control. This coefficient can be continuously adjusted and optimized according to actual production until it is finally solidified. After the start of feeding production, when a certain amount of material reaches the granulator, first set the unit set value according to experience, manually adjust the primary water frequency converter to a certain frequency, and observe the instantaneous flow rate after stabilization to be roughly consistent with the loop given value or slightly less than the loop given value, then it can be put into automatic mode; after the start of feeding production, when a certain amount of material reaches the granulator, manually adjust the liquid ammonia regulating valve to a certain valve position according to experience, and observe the instantaneous flow rate after stabilization to be roughly consistent with the set value or slightly less than the loop given value, then it can be put into automatic mode; after the primary water flow is stable, manually and step by step adjust the concentrated acid flow frequency converter to a certain value, and observe the instantaneous flow rate after stabilization to be roughly consistent with the set value or slightly less than the loop given value. When the steam flow rate is slightly less than the given value of the loop, it can be put into automatic mode; after starting feeding production, when a certain amount of material reaches the granulator, first set the unit setting value according to experience, and then manually adjust the steam regulating valve to a certain valve position. After stabilization, observe that the instantaneous flow rate is roughly consistent with the setting value or slightly less than the given value of the loop, then it can be put into automatic mode, and observe the granulation effect at the same time, and make fine adjustments to the feeding steam setting value in time according to the granulation effect; when return material occurs, observe whether the movement direction and amplitude of the regulating valve basically match the return material quantity according to the pre-set return material steam unit setting value. At this stage, we should also focus on the granulation effect and make fine adjustments to the return material setting value according to the granulation effect.

[0066] In addition, except for the interlocking of primary water and concentrated acid (water first and then acid), liquid ammonia and steam can be freely selected to be put into use according to the actual situation. For example, when only steam is used for granulation, the other three regulating loops can be left unused; when production is abnormal, the four control loops can be switched to manual with one key, and the valve position and frequency number can be appropriately reduced to ensure that the material does not form scars, and then manually adjusted to stabilize and then put into automatic again; the one-key stop button in the main control room is activated (emergency stop), and all regulating loops are automatically set to 0.

[0067] Specifically, before the system was put into operation, the operators relied on manual experience to control the system. After the frequency of the tail wash water pump reached a certain HZ, it was basically no longer fine-tuned, and could not change in time with the change of the material entering the granulator, resulting in unstable granulation effect and indirectly increasing the amount of system return material. In addition, the amount of tail wash water used should be determined according to the different compatibility of the materials. The amount used for each formula is different, and the amount of steam added must also be considered before it can be finally determined.

[0068] After the system was put into operation, under the premise of accurate material measurement, the granulation effect was basically stable, the system return material was greatly reduced and basically stable, and the adjustment frequency was significantly reduced. With the continuous use time and the continuous accumulation of experience data, a batch of experience data for each formula will be formed to guide production.

[0069] Example 2

[0070] Before this system was put into operation, operators relied entirely on manual experience for control. After the frequency of the sulfuric acid pump reached a certain HZ, it was basically no longer fine-tuned and could not change in time with the changes in the material entering the granulator, resulting in unstable granulation effects and indirectly increasing the amount of returned material in the system.

[0071] After the system was put into operation, under the premise of accurate material measurement, the granulation effect was basically stable, the system return material was greatly reduced and basically stable, and the adjustment frequency was significantly reduced.

[0072] Example 3

[0073] Before the system was put into operation, the operators relied entirely on manual experience for control. After the manual valve was opened to a certain degree, it was adjusted intermittently based on the operator's operating experience. It could not change in time with the changes in the materials entering the granulator, resulting in unstable granulation effects and indirectly increasing the amount of system return materials. In addition, as the operating experience of different operators is different, the steam consumption fluctuates greatly and the shift output varies greatly.

[0074] After the system is put into operation, under the premise of accurate material measurement, the steam consumption can be adjusted in time according to the amount of material entering the granulator, the granulation effect is basically stable, and the system return material is greatly reduced and basically stable.

[0075] The amount of steam used should be determined according to the different compatibility of materials. The amount used for each formula is different. At the same time, the amount of feed and return material added must be considered before the final determination can be made. After the system was put into operation, the granulation effect was basically stable, the system return material was greatly reduced and basically stable, and the adjustment frequency was significantly reduced. With the continuous use time and the continuous accumulation of experience data, a batch of experience data for each formula will be formed to guide production.

[0076] Example 4

[0077] Before this system was put into operation, operators relied entirely on manual experience for control. After the opening of the manual valve was basically fixed, it was basically no longer fine-tuned, and it could not change in time with the changes in the material entering the granulator, resulting in unstable granulation effects and indirectly increasing the amount of returned materials in the system.

[0078] After the system is put into operation, under the premise of accurate material measurement, the amount of liquid ammonia can be adjusted in time according to the amount of material entering the granulator. The granulation effect is basically stable, the system return material is greatly reduced and basically stable, and the adjustment frequency is significantly reduced.

[0079] In summary, the addition of saturated steam, primary water, concentrated sulfuric acid, and liquid ammonia media in the traditional double-drying and double-cooling drum process granulation process is changed from manual addition to DCS automatic control. Specifically, the amount of saturated steam, primary water, concentrated sulfuric acid, and liquid ammonia media added is based on the basic parameters of the feeding scale of the powdered material. In order to achieve the precise addition of the above media, the concept of material quantity mean is introduced for the first time, that is, the instantaneous correction value of each feeding scale is increased, and timely corrections are made based on the data comparison of the feeding to ensure the accuracy of the basic parameters, thereby ensuring the accuracy of the data collected by the control loop, so as to achieve automatic control of the addition of the above media. The material quantity mean is the average value calculated based on the feeding amount and return amount of the drum production line according to the length of time. The specific content of the self-adjusting circuit of the above media is as follows:

[0080] Primary water flow control: calculate the average value according to the feeding amount and return amount of the drum production line according to the length of time, and then automatically collect the benchmark data of the control loop (primary water flow, return amount average, feeding amount average) at the moment of switching between manual and automatic modes, and then automatically calculate the feeding (returning) unit primary water consumption, and then calculate the real-time given value data based on the unit primary water consumption combined with the return amount average, feeding amount average and the moisture content of the material at the outlet of the online quantitative granulator, and adjust the frequency of the primary water pump at a low frequency to make it close to the given value, and finally realize automatic control of the loop.

[0081] Sulfuric acid flow control: Calculate the average value of the feed and return amounts of the drum production line according to the length of time, and then automatically collect the benchmark data of the control loop (sulfuric acid flow, return amount average, feed amount average) at the moment of switching between manual and automatic modes, and then automatically calculate the unit sulfuric acid dosage of the feed (return), and then calculate the real-time given value data based on the unit sulfuric acid dosage combined with the return amount average, feed amount average and the moisture content of the material at the outlet of the online quantitative granulator, and adjust the frequency of the sulfuric acid pump at a low frequency to make it close to the given value, and finally realize automatic control of the loop.

[0082] Steam flow control: Calculate the average value of the feed and return amounts of the drum production line according to the length of time, and then automatically collect the benchmark data (steam flow, return amount, feed amount) of the control loop at the moment of switching between manual and automatic modes, and then calculate the unit steam consumption of the feed (return). Then, based on the unit steam consumption, combined with the average return amount, the average feed amount and the moisture content of the material at the outlet of the online quantitative granulator, calculate the real-time given value data, adjust the steam regulating valve to make it close to the given value, and finally realize automatic control of the loop.

[0083] Liquid ammonia flow control: Calculate the average value of the feed and return amounts of the drum production line according to the length of time, and then automatically collect the benchmark data of the control loop (liquid ammonia flow, return amount average, feed amount average) at the moment of switching between manual and automatic modes, and then automatically calculate the unit liquid ammonia dosage of the feed (return), and then calculate the real-time given value data based on the unit liquid ammonia dosage combined with the return amount average, feed amount average and the moisture content of the material at the outlet of the online quantitative granulator, and adjust the opening of the liquid ammonia regulating valve at a low frequency to make it close to the given value, and finally realize automatic control of the loop.

[0084] Through the design of the above medium addition self-adjusting loop, the automatic control of the drum granulation material is realized, and the intelligent control of the drum granulation device is realized. The patent of this invention sets the control scheme through the core control idea, designs the operation mode, thereby realizing the quantification of the formulation process parameters, and improving the control stability and granulation stability.

[0085] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent control method for amino acid granulation, characterized in that: The method is based on the DCS control system, which adjusts the medium flow rate at a low frequency through the regulating valve according to the real-time given value data, so as to make it approach the given value, achieve automatic control of the loop, and then realize automatic control of granulation; The real-time given value data is calculated based on the reference data of the acquisition circuit and the real-time collected feed amount, return amount and moisture content of the material, combined with the preset proportional coefficient and moisture adjustment coefficient; the specific calculation formula is as follows: SV = (M 投 * x / Q 水 + M 返 * x / Q 水 ) * M 总 * y * A 水 (Equation Ⅰ); Where, SV: real-time calculation of the given value outside the loop; M 投 : average feeding amount; M 返 : Mean value of returned material; M 总 : Total amount of material; X: Proportional coefficient; Y: Moisture adjustment coefficient; A 水 : Moisture content of materials; Q 水 : Primary water flow.

2. The intelligent control method for amino acid granulation according to claim 1, characterized in that: The benchmark data includes the collected flow data, feeding data and return data; and the acquisition process of the calculation formula is as follows: Step 1: Collect baseline quantities At the moment when the corresponding self-regulating loop switches to the automatic mode, the feed amount, return amount and moisture content of the material are collected in real time, and the steam flow rate, the average feed amount and the average return amount are used as the benchmark control data; And calculate the unit feed steam quantity by the following formula; Unit feed steam quantity = Q 蒸汽 / (feeding amount + return amount)*proportional coefficient (Formula II); Step 2: Calculate the unit return steam volume Feed steam volume = unit feed steam volume * feed volume Unit return steam volume = (Q 流量 - Feed steam amount) / return amount (Formula III); Step 3: Take the unit feed steam volume and unit return steam volume as the control parameter basis, and calculate the real-time SV value based on the transformation of feed volume and return volume. SV = (unit feed steam volume * average feed volume + unit return steam volume * average return volume) * moisture analysis data * moisture adjustment coefficient (Formula IV).

3. The intelligent control method for amino acid granulation according to claim 2, characterized in that: The loop is selected from any one of a primary water self-regulating loop, a concentrated sulfuric acid self-regulating loop, a steam self-regulating loop, and a liquid ammonia self-regulating loop, and each control loop is a closed-loop negative feedback control loop.

4. The intelligent control method for amino acid granulation according to claim 3, characterized in that: The primary water self-regulating circuit is interlocked with the concentrated sulfuric acid self-regulating circuit, and the primary water and concentrated sulfuric acid are mixed to prepare acid based on feed amount and concentration value.

5. The intelligent control method for amino acid granulation according to claim 3, characterized in that: The control process of the primary water self-adjusting loop is as follows: the average value of the feed amount and the return amount of the drum production line is calculated according to the time length, and then the benchmark data of the control loop is automatically collected at the moment of switching between manual / automatic modes, and then the unit primary water consumption is automatically calculated, and then the real-time given value data is calculated based on the unit primary water consumption combined with the average return amount, the average feed amount and the moisture content of the material at the outlet of the online quantitative granulator, and the frequency of the primary water pump is adjusted at a low frequency to make it close to the given value, so as to realize automatic control of the loop.

6. The intelligent control method for amino acid granulation according to claim 3, characterized in that: The control process of the concentrated sulfuric acid self-adjusting loop is as follows: the average value of the feed amount and the return amount of the drum production line is calculated according to the time length, and then the reference data of the control loop is automatically collected at the moment of switching between manual and automatic modes, and then the unit sulfuric acid dosage is automatically calculated, and then the real-time given value data is calculated based on the unit sulfuric acid dosage combined with the average return amount, the average feed amount and the moisture content of the material at the outlet of the online quantitative granulator, and the frequency of the sulfuric acid pump is adjusted at a low frequency to make it approach the given value, so as to finally realize the automatic control of the loop.

7. The intelligent control method for amino acid granulation according to claim 3, characterized in that: The control process of the steam self-regulating loop is: first, the instantaneous benchmark data of the automatic mode is obtained, and then the unit steam consumption is automatically calculated. Then, according to the unit steam consumption combined with the average return material amount, the average feed amount and the moisture content of the material on the online quantitative aging belt, the real-time given value data is calculated, and the steam regulating valve is adjusted at a low frequency to make it approach the given value, thereby finally realizing automatic control of the loop.

8. The intelligent control method for amino acid granulation according to claim 3, characterized in that: The control process of the liquid ammonia self-regulating loop is as follows: automatically collect the benchmark data at the moment of manual / automatic mode switching of each control loop, and then automatically calculate the unit liquid ammonia dosage, and then calculate the real-time given value data based on the unit liquid ammonia dosage combined with the average return material amount, the average feed amount and the moisture content of the material on the online quantitative aging belt, and adjust the frequency of the liquid ammonia pump at a low frequency to make it close to the given value, so as to finally realize automatic control of the loop.

9. The intelligent control method for amino acid granulation according to claim 1 or 2, characterized in that: The feeding amount and the returning amount are both measured by a metering belt; the moisture content of the material is measured in real time by an online moisture analyzer.

10. The intelligent control method for amino acid granulation according to any one of claims 1 to 8, characterized in that: The addition amount of saturated steam, primary water, concentrated sulfuric acid and liquid ammonia medium in the reaction medium is based on the comparison and correction of the feeding data by the mean value of the material amount; the said mean value of the material amount refers to the average value calculated by the feeding amount and the return amount of the drum production line according to the length of time.

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