Automatic control system and method for solid feeding and dissolving configuration

Abstract

The invention relates to the technical field of solid feeding, and particularly discloses an automatic control system and method for solid feeding and dissolution configuration, the system comprises a downstream receiving tank, a preparation tank, a second weighing bin, a first weighing bin and a stock bin, the top of the downstream receiving tank is connected with the preparation tank through a fourth pipeline, and the preparation tank is provided with a preparation tank circulation pipeline; the top of the preparation tank is connected with a second weighing bin through a third pipeline, the top of the second weighing bin is connected with a first weighing bin through a second pipeline, and the top of the first weighing bin is connected with a stock bin through a first pipeline. A DCS (Distributed Control System) commonly used in chemical production is combined with solid feeding equipment, so that a configuration mode of any proportion can be realized under the condition of not changing any equipment and facilities. And moreover, an operator can realize the solid charging, dissolving, configuring and discharging processes only by one-key starting, so that the operation difficulty of the operator in the configuring process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of solid feeding, in particular to an automatic control system and method for solid feeding and dissolving configuration. Background Art

[0002] In chemical production, solid feeding is a common feeding method. Solid feeding is inevitably accompanied by dust and other problems. Therefore, a simple solid system has always been a key link affecting the beauty of the entire workshop, environmental pollution control, and the development of workers' occupational health. With the development of chemical technology, various new solid feeding equipment have emerged at home and abroad. However, in many fine chemical production links, solid materials are often added in batches at one time. At this time, a simple bucket solid feeder becomes the first choice because of its simple structure, convenient maintenance, and low cost. The defects of the commonly used feeding methods on the market: 1: Either manual weighing and feeding, low degree of automation. Or even if there is an automatic weighing system, it is impossible to achieve simple switching of different ratios; or the operation is complicated, and the operator needs to be very skilled to ensure that there will be no mistakes. For operators who have just joined the company, the operation is complicated and slow to get started; 2: The entire system is not sealed, which causes damage to the environment and personnel; 3: The recovery system is not designed, and the loss is large; For this reason, an automatic control system and method for solid feeding and dissolution configuration are provided. Summary of the invention

[0003] The purpose of the present invention is to provide an automatic control system and method for solid feeding and dissolving configuration in view of the defects of the prior art, so as to solve the problems raised by the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an automatic control system for solid feeding and dissolution configuration, comprising a downstream receiving tank, a preparation tank, a second weighing bin, a first weighing bin and a silo, the top of the downstream receiving tank is connected to the preparation tank through a fourth pipeline, a preparation tank circulation pipeline is installed on the preparation tank, the top of the preparation tank is connected to the second weighing bin through a third pipeline, the top of the second weighing bin is connected to the first weighing bin through a second pipeline, the top of the first weighing bin is connected to the silo through a first pipeline, the tops of the preparation tank, the second weighing bin, the first weighing bin and the silo are all connected to a nitrogen purge pipeline, and the preparation tank is also connected to a solvent addition pipeline.

[0005] As a preferred technical solution of the present invention, one end of the preparation tank circulation pipeline is connected to the top of the preparation tank, and the other end of the preparation tank circulation pipeline is connected to the feed pipeline at the top of the downstream receiving tank. A preparation tank circulation pump and a preparation tank circulation pipeline pump outlet valve are installed on the preparation tank circulation pipeline.

[0006] As a preferred technical solution of the present invention, a preparation tank feeding pipeline tuning fork and a preparation tank feeding valve are installed on the fourth pipeline connecting the bottom of the preparation tank with the top of the downstream receiving tank, and a feeding configuration system cleaning pipeline is connected to the fourth pipeline between the preparation tank feeding pipeline tuning fork and the preparation tank feeding valve.

[0007] As a preferred technical solution of the present invention, agitators are installed inside the preparation tank and the downstream receiving tank, a low liquid level tuning fork and a preparation tank liquid level gauge are also installed on the preparation tank, a solvent flow meter, a flow accumulator and a regulating valve are installed on the solvent addition pipeline, the solvent flow meter and the flow accumulator are electrically connected to the regulating valve, and a pressure relief pipeline is also connected to the top of the preparation tank, and a pressure relief valve is installed on the pressure relief pipeline.

[0008] As a preferred technical solution of the present invention, a fourth nitrogen purge valve is installed on the nitrogen purge pipeline connected to the silo, a third vibration motor is installed on the silo, and the third vibration motor is used to shake the material in the silo to the downstream, and a fifth valve and a hook are provided on the top of the silo.

[0009] As a preferred technical solution of the present invention, a sixth valve is installed on the first pipeline connecting the silo and the first weighing bin, a sieve plate is installed inside the first weighing bin, and a first vibration motor and a first weighing scale are also installed on the first weighing bin. The first vibration motor is used to vibrate the material in the first weighing bin, and the first weighing scale is used to weigh the material in the first weighing bin. A third nitrogen purge valve is installed on the nitrogen purge pipeline connected to the top of the first weighing bin.

[0010] As a preferred technical solution of the present invention, a fourth valve is installed on the second pipeline connecting the first weighing bin and the second weighing bin, a second vibration motor and a second weighing scale are installed on the second weighing bin, the second vibration motor is used to vibrate the material in the second weighing bin, the second weighing scale is used to weigh the material in the second weighing bin, a pressure relief pipeline with a third valve is connected to the top of the second weighing bin, and a second nitrogen purge valve is installed on the nitrogen purge pipeline connected to the top of the second weighing bin.

[0011] As a preferred technical solution of the present invention, a first valve is installed on the third pipeline connecting the second weighing bin and the preparation tank, a dust collecting pipeline is connected to the third pipeline near the bottom of the second weighing bin, one end of the dust collecting pipeline is connected to the dust collector, and a second valve is installed on the dust collecting pipeline. A preparation tank thermometer and a heating system are also installed on the preparation tank, a steam valve is installed on the heating system, the preparation tank thermometer is electrically connected to the steam valve, and the preparation tank thermometer is used to monitor and control the material in the preparation tank to maintain the required temperature.

[0012] A method for solid feeding and dissolving using the above automatic control system, the specific steps are as follows: Step 1: a fixed amount of solvent is transported to a preparation tank through a solvent adding pipeline, a solvent flow meter and a flow accumulator are arranged on the solvent adding pipeline, the signals of the solvent flow meter and the flow accumulator are connected to a DCS control system, and when the accumulated amount is reached, the regulating valve on the solvent adding pipeline will automatically close; a fixed amount of solvent is stirred in the preparation tank through a stirrer; at the same time, the operator selects whether the solvent starts to circulate in step 2 according to the solubility of the solid solute, so as to ensure that the solid solute will not accumulate in the preparation tank and affect the dissolution effect after being added under the action of gravity;

[0013] Step 2: After passing through the silo, the solid solute is weighed in the first weighing bin and the second weighing bin in turn, and the weighed solid solute is added to the preparation tank; in order to ensure that there is less solid solute remaining in the pipeline added to the preparation tank, a nitrogen purge pipeline is used for continuous nitrogen purge, and the solid dust is collected by the dust collector in the purge pipeline and recycled regularly;

[0014] Step 3: The solvent and solute are heated to the required dissolution temperature in the preparation tank so that the solid material can be better dissolved in the preparation tank; the preparation tank is provided with a temperature control system for controlling the dissolution temperature; at the same time, the preparation tank is provided with a preparation tank level gauge to detect whether the solvent is volatilized; in step 3, the operator determines whether to open the circulation pipeline of the preparation tank according to the needs to ensure that the solid material can be fully dissolved;

[0015] Step 4: Add the prepared solution in the preparation tank to the downstream receiving tank.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Combining the DCS control system commonly used in chemical production with the solid feeding equipment, any ratio of configuration can be achieved without changing any equipment or facilities. Moreover, the operator only needs to start with one button to realize the process of solid feeding dissolution configuration and feeding, which reduces the difficulty of the operator's operation during the configuration process.

[0018] 2. In addition, during the solid feeding process, the entire system is fully enclosed, which can greatly reduce problems such as dust and dust, and avoid secondary damage to personnel and the environment during operation.

[0019] 3. Design a recovery system to effectively improve solid utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 The present invention is a flow chart of the method.

[0022] In the figure: 1- downstream receiving tank; 2- preparation tank circulation pump; 3- preparation tank circulation pipeline; 4- preparation tank circulation pipeline pump outlet valve; 5- preparation tank thermometer; 6- heating system; 7- steam valve; 8- preparation tank feeding pipeline tuning fork; 9- preparation tank feeding valve; 10- feeding preparation system cleaning pipeline; 11- low liquid level tuning fork; 12- preparation tank liquid level meter; 13- solvent flow meter and flow accumulator; 14- regulating valve; 15- first nitrogen purge valve; 16- second nitrogen purge valve; 17- third nitrogen purge valve; 18- fourth nitrogen purge Sweep valve; 19-second weighing bin; 20-first valve; 21-pressure relief valve; 22-second valve; 23-dust collector; 24-second vibration motor; 25-second weighing scale; 26-third valve; 27-fourth valve; 28-first vibration motor; 29-first weighing scale; 30-third vibration motor; 31-fifth valve; 32-hook; 33-agitator; 34-preparation tank; 35-first weighing bin; 36-sieve plate; 37-sixth valve; 38-solvent addition pipeline, 39-nitrogen purge pipeline; 40-silo. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0024] See also Figure 1 The present invention provides a technical solution: an automatic control system for solid feeding and dissolving configuration, comprising a downstream receiving tank 1, a preparation tank 34, a second weighing bin 19, a first weighing bin 35 and a silo 40, wherein the top of the downstream receiving tank 1 is connected to the preparation tank 34 via a fourth pipeline, a preparation tank circulation pipeline 3 is installed on the preparation tank 34, the top of the preparation tank 34 is connected to the second weighing bin 19 via a third pipeline, the top of the second weighing bin 19 is connected to the first weighing bin 35 via a second pipeline, and the top of the first weighing bin 35 is connected to the silo 40 via a first pipeline. The tops of the preparation tank 34, the second weighing bin 19, the first weighing bin 35 and the silo 40 are all connected with a nitrogen purge pipeline 39. The purpose of nitrogen purge is to prevent the powder in the pipeline from absorbing moisture after accumulation, which makes the material unloading inaccurate and blocks the pipeline in serious cases. Another important purpose is that if the downstream environment has high requirements for oxygen content, the purpose of nitrogen purge is to replace the powder with nitrogen to prevent oxygen from being brought into the downstream. The functions of the preparation tank 34, the second weighing bin 19, the first weighing bin 35 and the silo 40 are the same, which is to prevent the powder from absorbing moisture after accumulation in the pipeline and blocking the pipeline. In addition, another purpose of nitrogen purge of the preparation tank 34 is nitrogen replacement to prevent the negative impact of oxygen content. The preparation tank 34 is also connected with a solvent addition pipeline 38.

[0025] One end of the preparation tank circulation pipeline 3 is connected to the top of the preparation tank 34, and the other end of the preparation tank circulation pipeline 3 is connected to the feed pipeline at the top of the downstream receiving tank 1. The preparation tank circulation pipeline 3 is installed with a preparation tank circulation pump 2 and a preparation tank circulation pipeline pump outlet valve 4. The purpose of setting the circulation pump and pipeline is to prevent the material with low solubility from being poorly dissolved only under stirring, resulting in inconsistent mass fractions of the upper solution and the lower solution. In severe cases, solid materials are precipitated, and the amount added downstream is inaccurate. After adding the circulation pump and pipeline, the contact area between the solid material and the solute is increased, and stratification is not easy to occur.

[0026] The fourth pipeline connecting the bottom of the preparation tank 34 and the top of the downstream receiving tank 1 is installed with a preparation tank feeding pipeline tuning fork 8 and a preparation tank feeding valve 9. ， The purpose of the tuning fork is to determine whether the pipeline is empty during feeding and to ensure that the material is discharged. The fourth pipeline between the tuning fork 8 of the preparation tank feeding pipeline and the preparation tank feeding valve 9 is connected with a feeding configuration system cleaning pipeline 10. When the solid solute required downstream is replaced, for example, when the catalyst of the polyether polyol device is replaced from potassium hydroxide to sodium methoxide, in order to ensure the cleanliness of the system, the configuration system needs to be thoroughly cleaned, and the sewage after cleaning is sent to the sewage treatment through this pipeline.

[0027] A stirrer 33 is installed inside the preparation tank 34 and the downstream receiving tank 1 to ensure that the prepared solution can be evenly distributed in the receiving tank. A low liquid level tuning fork 11 and a preparation tank liquid level gauge 12 are also installed on the preparation tank 34. A solvent flow meter and flow accumulator 13 and a regulating valve 14 are installed on the solvent adding pipeline 38. ， The solvent flow meter and flow accumulator 13 are electrically connected to the regulating valve 14 to control the start and stop of the regulating valve and to adjust the opening of the valve. A pressure relief pipeline is also connected to the top of the preparation tank 34, and a pressure relief valve 21 is installed on the pressure relief pipeline to ensure that the pressure inside the preparation tank is within a suitable range to avoid the danger of overpressure.

[0028] A fourth nitrogen purge valve 18 is installed on a nitrogen purge pipeline 39 connected to the silo 40. A third vibration motor 30 is installed on the silo 40. The third vibration motor 30 is used to shake the material in the silo to the downstream. A fifth valve 31 and a hook 32 are provided on the top of the silo 40. ， The hook 32 is installed directly above the silo 40 to ensure that it does not hinder the operator's operation under safe conditions; the fifth valve 31 is installed on a floor bracket next to the silo 40; there are "start / stop, up, down, left, right" and other necessary buttons on it. After the operator clicks "start / stop", the hook starts, and by clicking the "up, down, left, right" buttons, the hook is connected to the top of the silo.

[0029] A sixth valve 37 is installed on the first pipeline connecting the silo 40 and the first weighing bin 35. A sieve plate 36 is installed inside the first weighing bin 35. A first vibration motor 28 and a first weighing scale 29 are also installed on the first weighing bin 35. The first vibration motor 28 is used to vibrate the material in the first weighing bin 35. The first weighing scale 29 is used to weigh the material in the first weighing bin 35. A third nitrogen purge valve 17 is installed on the nitrogen purge pipeline 39 connected to the top of the first weighing bin 35.

[0030] A fourth valve 27 is installed on the second pipeline connecting the first weighing bin 35 and the second weighing bin 19, a second vibration motor 24 and a second weighing scale 25 are installed on the second weighing bin 19, the second vibration motor 24 is used to vibrate the material in the second weighing bin 19, the second weighing scale 25 is used to weigh the material in the second weighing bin 19, a pressure relief pipeline with a third valve 26 is connected to the top of the second weighing bin 19, and a second nitrogen purge valve 16 is installed on the nitrogen purge pipeline 39 connected to the top of the second weighing bin 19.

[0031] A first valve 20 is installed on the third pipeline connecting the second weighing bin 19 and the preparation tank 34. A dust collecting pipeline is connected to the third pipeline near the bottom of the second weighing bin 19. The dust collecting pipeline is used to collect solid dust raised during feeding to reduce occupational health hazards. One end of the dust collecting pipeline is connected to the dust collector 23. A second valve 22 is installed on the dust collecting pipeline. A preparation tank thermometer 5 and a heating system 6 are also installed on the preparation tank 34. A steam valve 7 is installed on the heating system 6. The preparation tank thermometer 5 is electrically connected to the steam valve 7. The preparation tank thermometer 5 is used to monitor and control the material in the preparation tank 34 to maintain the required temperature.

[0032] like Figure 2 As shown, a method for solid feeding and dissolving configuration using the above-mentioned automatic control system, the specific steps are as follows: Step 1: a fixed amount of solvent is transported to the preparation tank 34 through the solvent adding pipeline 38, and a solvent flow meter and a flow accumulator 13 are arranged on the solvent adding pipeline 38. The signals of the solvent flow meter and the flow accumulator 13 are connected to the DCS control system. When the accumulated amount is reached, the regulating valve 14 on the solvent adding pipeline 38 will be automatically closed; the fixed amount of solvent is stirred in the preparation tank 34 by the stirrer 33; at the same time, the operator selects whether the solvent starts to circulate in step 2 according to the solubility of the solid solute, so as to ensure that the solid solute will not accumulate in the preparation tank and affect the dissolution effect after being added under the action of gravity;

[0033] Step 2: After passing through the silo 40, the solid solute is weighed in the first weighing bin 35 and the second weighing bin 19 in turn, and the weighed solid solute is added to the preparation tank 34; in order to ensure that there is less solid solute remaining in the pipeline added to the preparation tank 34, a nitrogen purge pipeline 39 is used for continuous nitrogen purge, and the solid dust is collected by the dust collector 23 in the purge pipeline and recycled regularly;

[0034] Step 3: The solvent and the solute are heated to the required dissolution temperature in the preparation tank 34 so that the solid material can be better dissolved in the preparation tank; the preparation tank 34 is provided with a temperature control system for controlling the dissolution temperature; at the same time, the preparation tank 34 is provided with a preparation tank level gauge 12 to detect whether the solvent is volatilized; in step 3, the operator determines whether to open the preparation tank circulation pipeline 3 according to the needs to ensure that the solid material can be fully dissolved;

[0035] Step 4: Add the prepared solution in the preparation tank 34 to the downstream receiving tank 1.

[0036] Example 1: 400 kg of potassium hydroxide is used as solid material, and 4000 kg of water is used as solvent. First, these two values ​​are input into the DCS system as set values. These two values ​​can be modified to configure solutions with different solubilities. And these two data are used as judgment conditions for specific steps to reduce the difficulty of operation for the operator during the configuration process. The preparation tank 34 is provided with a preparation tank circulation pipeline 3, and it can be selected whether to open the circulation according to the solubility of different substances and to increase the start-up circulation pipeline after dissolving to a certain extent. In addition, the above instruments are all in the DCS system, and are programmed accordingly according to the operating steps. The operator only needs to click start, and the DCS system will operate according to the corresponding steps, truly realizing one-key operation.

[0037] S1: The steps are as follows:

[0038] S1-1: Water from a storage tank or directly from a pipeline is introduced into the preparation tank 34 through the solvent addition pipeline 38. A flow meter, a flow accumulator 13 and a regulating valve 14 are provided on the solvent addition pipeline 38. The flow meter and the flow accumulator 13 are connected to the regulating valve 14. Before the deionized water is introduced, the flow accumulation FIQ will be cleared. When the value of FIQ reaches 3000kg, the signal is transmitted to the regulating valve 14, and the opening of the regulating valve 14 will be adjusted from a higher opening of 80-90% to an opening of 30%, and then the introduction will continue at this opening. When the value of FIQ reaches 4000kg, the opening of the regulating valve 14 is adjusted to 0%. The preparation tank 34 is equipped with a preparation tank level gauge 12 and a low liquid level tuning fork 11. When the deionized water added is less than 300kg, the low liquid level tuning fork 11 is always in an activated state, and when it exceeds 300kg, the low liquid level tuning fork 11 will not be activated. When 2000 kg of deionized water is added, the preparation tank level meter 12 shows that the liquid level of the preparation tank is 33%. At this time, the stirrer 33 will start stirring because the liquid level value is met. The purpose of setting these two level meters at the same time can also ensure that deionized water is added to the preparation tank 34 again, and the accuracy and repeatability of the same concentration can be compared from the DCS curves of the two level meters.

[0039] S1-2: After 4000 kg of deionized water is added, the solvent flow meter and flow accumulator 13 will stop accumulating, the regulating valve 14 will be closed, and the valve closing signal will be transmitted to the DCS to ensure that deionized water will not be added to the preparation tank 34. The operator chooses whether to open the preparation tank circulation pipeline 3. If the preparation tank circulation pipeline 3 is opened, then the process proceeds to step S1-3. If the preparation tank circulation pipeline 3 is not opened, then the process proceeds to step S2-1.

[0040] S1-3: After the deionized water is added, the preparation tank feed valve 9 will be opened, and when the preparation tank feed pipeline tuning fork 8 changes from an activated state to an inactivated state, the preparation tank circulation pipeline pump outlet valve 4 will be opened, and after the preparation tank circulation pipeline pump outlet valve 4 is opened for 30 seconds and the preparation tank feed pipeline tuning fork 8 shows that there is material, the preparation tank circulation pump 2 will be started. At this time, step S1 is completed. The preparation tank 34 keeps the stirring turned on and the pump running in a circulating state. Next or at the same time as this step, the weighing of solid potassium hydroxide is carried out. If the solubility of the added solid material in the solvent is low, step S1-3 can be skipped first.

[0041] S2: The steps are as follows: S2-1; The operator transports a bag of 500kg potassium hydroxide to the potassium hydroxide feeding system, and then starts the hook 32 to lift the 500kg potassium hydroxide. The fifth valve 31 will open at the moment the hook 32 is started. The fifth valve is installed on the floor bracket next to the silo. There are "Start / Stop, Up, Down, Left, Right" and other necessary buttons on it. After the operator clicks "Start / Stop", the hook starts, and by clicking the "Up, Down, Left, Right" buttons, the hook is connected to the top of the silo.

[0042] S2-2: After 500 kg of potassium hydroxide is added to the silo, the outer packaging bag will be torn open, and then the hook will fall off, and the fifth valve 31 will be closed. The outer packaging bag will be temporarily sealed in the silo, but the packaging bag will be separated from the potassium hydroxide.

[0043] S2-3: Then the third vibration motor 30 in the silo will start and vibrate the material in the silo into the first weighing bin 35. A snap-fit ​​sieve plate 36 is provided in the first weighing bin 35 to separate the large particles of potassium hydroxide that absorb moisture and agglomerate. After the weighing is completed, the separated large particles will be collected and processed regularly. The usable potassium hydroxide filtered by the sieve plate 36 will be weighed by the first weighing scale 29 in the first weighing bin 35. When the weighing reaches 300kg±0.5kg, the vibration frequency of the third vibration motor 30 of the silo will be reduced to 50% of the original, and then the solid material will be added at a low-frequency vibration speed. When the first weighing scale 29 weighs 400kg±0.5kg, the third vibration motor 30 will stop, and the sixth valve 37 between the silo 40 and the first weighing bin 35 will be closed. The first weighing of 400kg potassium hydroxide is completed.

[0044] S2-4: After the third vibration motor 30 of the silo 40 stops for 30 seconds, the fourth nitrogen purge valve 18 is opened and closed after 30 seconds. The purpose of opening the fourth nitrogen purge valve 18 is to purge the silo with nitrogen so that the potassium hydroxide floating on the upper part of the silo is deposited to the bottom of the silo under the action of nitrogen.

[0045] S2-5: The 400kg potassium hydroxide weighed in the first weighing bin 35 is added to the second weighing bin 19. The fourth valve 27 between the first weighing bin 35 and the second weighing bin 19 is opened, and the first vibration motor 28 is started. When the second weighing scale 25 weighs 300kg±0.5kg, the vibration frequency of the first vibration motor 28 of the first weighing bin 35 will be reduced to 50% of the original, and then the solid material will be added at a low frequency vibration speed. When the second weighing scale 25 weighs 400kg±0.5kg, the first vibration motor 28 will stop, and the fourth valve 27 will be closed. The second weighing of 400kg potassium hydroxide is completed.

[0046] S2-6: After the first vibration motor 28 of the first weighing bin 35 stops for 30 seconds, the third nitrogen purge valve 17 is opened and maintained for 60 seconds before being closed. The purpose of opening the third nitrogen purge valve 17 is to purge the first weighing bin 35 with nitrogen so that the potassium hydroxide floating on the upper part of the bin is deposited to the bottom of the first weighing bin 35 under the action of nitrogen. Only then is the potassium hydroxide weighing completed.

[0047] S2-7: The potassium hydroxide weighed twice is transferred from the second weighing bin 19 to the preparation tank 34. First, it is required that the bottom of the second weighing bin 19 and the top of the preparation tank 34 are installed vertically at 90 degrees and the distance between the two is the shortest, so that there is less potassium hydroxide remaining in the pipeline and the moisture backflow process in the preparation tank 34 is reduced. The first valve 20 and the second valve 22 are managed as a set of valve groups. When the first valve 20 is opened, the second valve 22 remains closed, and when the first valve 20 is closed, the second valve 22 remains open. When the potassium hydroxide in the second weighing bin 19 is added to the preparation tank 34, the second valve 22 is closed first, and the first valve 20 is opened only after the DCS receives the feedback signal of the second valve 22 being closed. After the DCS simultaneously receives the closing feedback signal of the second valve 22 and the opening feedback signal of the first valve 20, the second vibration motor 24 is turned on to vibrate all the potassium hydroxide in the second weighing bin 19 into the preparation tank 34. When the weighing scale in the second weighing bin 19 is 0, the second vibration motor 24 stops after vibrating for 30 seconds. If the value of the second weighing scale 25 in the second weighing bin 19 is greater than 0 at this time, the second vibration motor 24 is started again and stops after continuing to vibrate for 30 seconds. Until the second vibration motor 24 stops, the value of the weighing scale 25 in the second weighing bin 19 is ≤0. The first valve 20 is closed after the dual signal of the value of the weighing scale 25 ≤0 and the second vibration motor 24 stops. After the first valve 20 is closed, the second valve 22 is opened so that nitrogen can continue to purge the solid materials in the pipeline to the dust collector 23 in the purge line for collection.

[0048] S2-8: The operator confirms whether the fifth valve 31 is open and takes out the packaging bag. If it is not open, the packaging bag can be temporarily stored in the silo and taken out before the next feeding. This can effectively reduce the probability of the operator being exposed to dust.

[0049] S3: The steps are as follows:

[0050] S3-1: After potassium hydroxide is added to the preparation tank 34, it is first stirred and circulated and dissolved in the preparation tank 34. If it is a poorly soluble substance, the solute is only stirred and dissolved.

[0051] S3-2: This step will be performed if there are oxygen content requirements in the preparation tank, or if there are special requirements for oxygen content downstream of the preparation tank.

[0052] S3-2a: After potassium hydroxide is added to the preparation tank 34, the first nitrogen purge valve 15 of the preparation tank 34 is opened until the pressure of the preparation tank 34 reaches 0.2-0.3 MPaG, and then the first nitrogen purge valve 15 of the preparation tank is closed;

[0053] S3-2b: The pressure relief valve 21 of the preparation tank 34 is opened until the pressure of the preparation tank 34 drops to 0-0.1 MPaG, and then the pressure relief valve 21 of the preparation tank is closed. Repeat steps S3-2a and S3-2b 2-10 times to ensure that the oxygen content in the preparation tank meets the requirements.

[0054] S3-3: The preparation tank 34 will be heated by the heating system 6, and the temperature of the preparation tank 34 will be detected by the preparation tank thermometer 5. When the temperature of the preparation tank is lower than the required dissolution temperature of 50°C, the steam valve 7 in the heating system 6 will be opened; when the temperature of the preparation tank is higher than the required dissolution temperature of 50°C, the steam valve 7 in the heating system 6 will be closed, and the condensate drain valve will be opened. To ensure that the preparation tank 34 is maintained within the required range of 50°C ± 2°C. When the temperature is reached, the DCS system will remind the operator whether to start the circulation of the preparation tank. If the operator clicks No, it will enter S4. If the operator clicks Yes, then the S3-4 step will be executed.

[0055] S3-4: The preparation tank feed valve 9 will be opened, and when the preparation tank feed pipeline tuning fork 8 changes from the activated state to the inactivated state, the preparation tank circulation pipeline pump outlet valve 4 will be opened. After the preparation tank circulation pipeline pump outlet valve 4 is opened for 30 seconds and the preparation tank circulation pipeline liquid level tuning fork shows that there is material, the preparation tank circulation pump 2 will be started. In order to make potassium hydroxide dissolve better, the cycle time is also set. The time from starting the pump to stopping the pump is defined as the cycle time. The cycle time can be modified arbitrarily by the operator in the DCS.

[0056] S3-5: Stop the preparation tank circulation pump 2 and close all valves and instruments on the preparation tank circulation pipeline 3.

[0057] S4: The steps are as follows:

[0058] S4-1: Open the preparation tank feed valve 9, and the material in the preparation tank 34 will be fed into the downstream receiving tank 1. Whether the material in the tank is emptied is confirmed by two instruments: the low liquid level tuning fork 11 and the preparation tank feed pipeline tuning fork 8. The two instruments have a double confirmation function to prevent one instrument from giving a false alarm and not emptying the tank.

[0059] S4-2: After the solution is emptied, the first nitrogen purge valve 15 is opened to purge the material in the preparation tank into the downstream receiving tank 1 again. After the purge is completed, the first nitrogen purge valve 15 is closed.

[0060] Post-processing process: Because some solvents are volatile substances, solid materials in the weighing system are easily dampened and adhere to the pipeline. In order to reduce the solid wall adhesion, we have adopted a continuous nitrogen purge process. In addition, the feeding system needs to be cleaned regularly to prevent the solid materials adhering to the wall from corroding the pipe wall and valves. During cleaning, the cleaning waste liquid will be collected in the preparation tank 34 and sent to the downstream waste liquid treatment system through the feeding configuration system cleaning pipeline 10 for unified treatment.

[0061] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. An automatic control system for solid feeding and dissolving configuration, comprising a downstream receiving tank (1), a preparation tank (34), a second weighing bin (19), a first weighing bin (35) and a silo (40), characterized in that: The top of the downstream receiving tank (1) is connected to a preparation tank (34) via a fourth pipeline, a preparation tank circulation pipeline (3) is installed on the preparation tank (34), the top of the preparation tank (34) is connected to a second weighing bin (19) via a third pipeline, the top of the second weighing bin (19) is connected to a first weighing bin (35) via a second pipeline, the top of the first weighing bin (35) is connected to a silo (40) via a first pipeline, the tops of the preparation tank (34), the second weighing bin (19), the first weighing bin (35) and the silo (40) are all connected to a nitrogen purge pipeline (39), and the preparation tank (34) is also connected to a solvent addition pipeline (38).

2. The automatic control system for solid feeding and dissolving configuration according to claim 1, characterized in that: One end of the preparation tank circulation pipeline (3) is connected to the top of the preparation tank (34), and the other end of the preparation tank circulation pipeline (3) is connected to the feed pipeline at the top of the downstream receiving tank (1). The preparation tank circulation pipeline (3) is installed with a preparation tank circulation pump (2) and a preparation tank circulation pipeline pump outlet valve (4).

3. The automatic control system for solid feeding and dissolving configuration according to claim 2 is characterized in that: A fourth pipeline connecting the bottom of the preparation tank (34) and the top of the downstream receiving tank (1) is provided with a preparation tank feed pipeline tuning fork (8) and a preparation tank feed valve (9). ， A fourth pipeline between the preparation tank feeding pipeline tuning fork (8) and the preparation tank feeding valve (9) is connected to a feeding and preparation system cleaning pipeline (10).

4. The automatic control system for solid feeding and dissolving configuration according to claim 1 is characterized in that: The preparation tank (34) and the downstream receiving tank (1) are both equipped with a stirrer (33), the preparation tank (34) is also equipped with a low liquid level tuning fork (11) and a preparation tank liquid level meter (12), and the solvent adding pipeline (38) is equipped with a solvent flow meter and a flow accumulator (13) and a regulating valve (14). ， The solvent flow meter and flow accumulator (13) are electrically connected to the regulating valve (14). The top of the preparation tank (34) is also connected to a pressure relief pipeline, and a pressure relief valve (21) is installed on the pressure relief pipeline.

5. The automatic control system for solid feeding and dissolving configuration according to claim 1, characterized in that: A fourth nitrogen purge valve (18) is installed on a nitrogen purge pipeline (39) connected to the silo (40), a third vibration motor (30) is installed on the silo (40), and the third vibration motor (30) is used to shake the material in the silo to the downstream, and a fifth valve (31) and a hook (32) are arranged on the top of the silo (40).

6. The automatic control system for solid feeding and dissolving configuration according to claim 1, characterized in that: A sixth valve (37) is installed on the first pipeline connecting the material bin (40) and the first weighing bin (35); a sieve plate (36) is installed inside the first weighing bin (35); a first vibration motor (28) and a first weighing scale (29) are also installed on the first weighing bin (35); the first vibration motor (28) is used to vibrate the material in the first weighing bin (35); the first weighing scale (29) is used to weigh the material in the first weighing bin (35); and a third nitrogen purge valve (17) is installed on the nitrogen purge pipeline (39) connected to the top of the first weighing bin (35).

7. The automatic control system for solid feeding and dissolving configuration according to claim 1, characterized in that: A fourth valve (27) is installed on the second pipeline connecting the first weighing bin (35) and the second weighing bin (19); a second vibration motor (24) and a second weighing scale (25) are installed on the second weighing bin (19); the second vibration motor (24) is used to vibrate the material in the second weighing bin (19); the second weighing scale (25) is used to weigh the material in the second weighing bin (19); a pressure relief pipeline installed with a third valve (26) is connected to the top of the second weighing bin (19); and a second nitrogen purge valve (16) is installed on the nitrogen purge pipeline (39) connected to the top of the second weighing bin (19).

8. The automatic control system for solid feeding and dissolving configuration according to claim 1, characterized in that: A first valve (20) is installed on the third pipeline connecting the second weighing bin (19) and the preparation tank (34); a dust collecting pipeline is connected to the third pipeline near the bottom of the second weighing bin (19); one end of the dust collecting pipeline is connected to the dust collector (23); a second valve (22) is installed on the dust collecting pipeline; a preparation tank thermometer (5) and a heating system (6) are also installed on the preparation tank (34); a steam valve (7) is installed on the heating system (6); the preparation tank thermometer (5) is electrically connected to the steam valve (7); and the preparation tank thermometer (5) is used to monitor and control the material in the preparation tank (34) to maintain a required temperature.

9. A method for solid feeding and dissolving using the automatic control system according to claims 1-8, characterized in that: The specific steps are as follows: Step 1: a fixed amount of solvent is delivered to a preparation tank (34) through a solvent adding pipeline (38). A solvent flow meter and a flow accumulator (13) are provided on the solvent adding pipeline (38). The signals of the solvent flow meter and the flow accumulator (13) are connected to a DCS control system. When the accumulated amount is reached, a regulating valve (14) on the solvent adding pipeline (38) is automatically closed. The fixed amount of solvent is stirred in the preparation tank (34) by a stirrer (33). At the same time, the operator selects whether to circulate the solvent in step 2 according to the solubility of the solid solute, so as to ensure that the solid solute does not accumulate in the preparation tank under the action of gravity after being added, thereby affecting the dissolution effect. Step 2: After passing through the silo (40), the solid solute is weighed in turn through the first weighing bin (35) and the second weighing bin (19), and the weighed solid solute is added to the preparation tank (34); in order to ensure that less solid solute remains in the pipeline for adding to the preparation tank (34), a nitrogen purge pipeline (39) is used for continuous nitrogen purge, and solid dust is collected by a dust collector (23) in the purge pipeline and recycled regularly; Step 3: The temperature of the solvent and the solute in the preparation tank (34) is raised to the required dissolution temperature so that the solid material can be better dissolved in the preparation tank; the preparation tank (34) is provided with a temperature control system for controlling the dissolution temperature; at the same time, the preparation tank (34) is provided with a preparation tank liquid level meter (12) to detect whether the solvent is volatilized; in step 3, the operator determines whether to open the preparation tank circulation pipeline (3) according to the needs to ensure that the solid material can be fully dissolved; Step 4: Add the prepared solution in the preparation tank (34) to the downstream receiving tank (1).

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