Vacuum crystallization automatic control system and automatic control method thereof

Abstract

The invention provides a vacuum crystallization automatic control system, which belongs to the technical field of chemical automation control, and comprises a vacuum crystallization tank, a pre-crystallization titanium liquid tank and a spraying condensation tank, the vacuum crystallizing tank is connected with a vacuum crystallizing tank discharge valve and a spray condensing tank; a discharge valve of the vacuum crystallizing tank is connected with the post-crystallization storage tank; the top of the spray condensation tank is connected with one end of the non-pressure circulating water tank through a crystallization non-pressure water inlet valve, the bottom is connected with the other end of the non-pressure circulating water tank through a crystallization non-pressure water return valve, and the side surface of the top of the spray condensation tank is connected with the vacuum pump through a vacuum pump emptying valve. Automatic equipment is added, so that the labor intensity of workers is reduced, and the execution accuracy is improved; operation is easy and convenient, the automation degree is high, the safety coefficient is high, stability is good, automatic control over procedures is truly achieved, labor intensity is relieved, and production cost is reduced. The invention also relates to an automatic control method of the vacuum crystallization automatic control system.

Description

Technical Field

[0001] This invention relates to the field of chemical automation control technology, and more specifically, to an automatic control system for vacuum crystallization. The invention also relates to an automatic control method for this automatic control system for vacuum crystallization. Background Technology

[0002] Currently, the automation level of conventional vacuum crystallization processes in the industry is low, with control relying on manual operation on-site and partial remote manual control. The main problems with manual control of vacuum crystallization processes are as follows:

[0003] 1) The vacuum crystallization process has strict requirements for vacuum degree, temperature control, cooling rate, and crystallization nucleation time. The temperature control during the vacuum crystallization process is strictly controlled. If manual operation is not timely, the amount added will be inaccurate, affecting product quality. If the valve is not closed or the pump is not stopped, it will cause leakage of hazardous chemicals and material loss, and in severe cases, personnel injury.

[0004] 2) Manual feeding is prone to overflowing or shortage of materials, which affects production efficiency. In addition, concentrated sulfuric acid is a hazardous chemical, and sulfuric acid leakage poses a significant safety hazard.

[0005] Therefore, it is necessary to develop an automatic control system for vacuum crystallization and its automatic control method. Summary of the Invention

[0006] The primary objective of this invention is to overcome the shortcomings of the aforementioned background technology and to provide an automatic control system for vacuum crystallization.

[0007] The second objective of this invention is to provide an automatic control method for such an automatic vacuum crystallization control system.

[0008] To achieve the aforementioned first objective, the technical solution of the present invention is as follows: an automatic control system for vacuum crystallization, characterized in that it includes a vacuum crystallization tank, a pre-crystallization titanium liquid tank, and a spray condensation tank; the bottom side of the vacuum crystallization tank is provided with a side stirrer, the bottom is connected to the vacuum crystallization tank discharge valve, the top is provided with an air vent valve, and the top is connected to the spray condensation tank; the vacuum crystallization tank discharge valve is connected to a post-crystallization storage tank; the pre-crystallization titanium liquid tank is sequentially connected to the top of the vacuum crystallization tank via the pre-crystallization titanium liquid tank discharge valve and the vacuum crystallization tank inlet valve, and connected to one end of the hot water exchange tank via a crystallization cold water inlet valve, and connected to the other end of the hot water exchange tank via a crystallization cold water return valve; the top of the spray condensation tank is connected to one end of the unpressurized circulating water pool via a crystallization unpressurized water inlet valve, and connected to the other end of the unpressurized circulating water pool via a crystallization unpressurized water return valve; the top side of the spray condensation tank is connected to a vacuum pump via a vacuum pump air vent valve.

[0009] In the above technical solution, a liquid phase temperature measuring device is provided on the bottom side of the vacuum crystallizer; a vacuum crystallization feed flow meter is provided between the discharge valve of the titanium liquid tank before crystallization and the feed valve of the vacuum crystallizer.

[0010] In the above technical solution, the top of the vacuum crystallization tank is connected to the spray condenser tank via a demister.

[0011] In the above technical solution, the hot water exchange tank is connected to the crystallization cold water inlet valve in sequence through a low-temperature water circulation pump, a pressure measuring device, and a water distributor.

[0012] In the above technical solution, the crystallization pressureless water return valve is connected to the pressureless circulating water tank in sequence through a cooling water liquid seal tank and a spray water pump.

[0013] In the above technical solution, the vacuum pump is connected to the vacuum pump vent valve in sequence through a two-stage Roots pump and a first-stage Roots pump.

[0014] To achieve the second objective mentioned above, the technical solution of the present invention is: an automatic control method for a vacuum crystallization automatic control system, characterized by comprising the following steps:

[0015] Step 1: Click "Auto" to reset all timers and the step sequence, and initialize the device;

[0016] Step 2: Start the program, open the vacuum crystallizer feed valve, and start the side agitator;

[0017] Step 3: Open the discharge valve of the titanium liquid tank before crystallization;

[0018] Step 4: The vacuum crystallization feed flow meter starts to accumulate metering. When the set accumulated flow rate is reached, the discharge valve of the titanium liquid tank before crystallization is closed, and the feed valve of the vacuum crystallization tank is closed.

[0019] Step 5: Close the vent valve;

[0020] Step 6: Open the vacuum pump vent valve and turn on the vacuum pump;

[0021] Step 7: After the vacuum pump has been running for 120 seconds, close the vacuum pump vent valve.

[0022] Step 8: After the system vacuum reaches the set vacuum level, start the second-stage Roots pump first, and then start the first-stage Roots pump.

[0023] Step 9: When the vacuum degree of the vacuum crystallizer reaches the set vacuum degree, open the crystallization pressureless water return valve, while the crystallization cold water inlet valve and the crystallization cold water return valve are in the closed state.

[0024] Step 10: Open the unpressurized water inlet valve for crystallization;

[0025] Step 11: Detect the liquid phase temperature in the vacuum crystallizer using a liquid phase temperature measuring device until it reaches the set temperature T1, then close the pressureless water inlet valve for crystallization.

[0026] Step 12: Open the crystallization cold water inlet valve to the set opening degree 1;

[0027] Step 13: Start the cryogenic water circulation pump;

[0028] Step 14: Open the crystallization cold water return valve and close the crystallization unpressurized water return valve;

[0029] Step 15: When the liquid phase temperature of the vacuum crystallizer reaches the set value T2 of the crystallization point temperature, adjust the crystallization cold water inlet valve to the set opening degree 2.

[0030] Step 16: When the liquid phase temperature of the vacuum crystallizer is less than the set value of the crystallization point temperature T2, and the duration is greater than the set duration 1, adjust the crystallization cold water inlet valve to the set opening degree 1.

[0031] Step 17: When the liquid phase temperature of the vacuum crystallizer reaches the discharge set temperature T3 as detected by the liquid phase temperature measuring instrument, close the crystallization cold water inlet valve and the crystallization cold water return valve.

[0032] Step 18: Stop the vacuum pump; stop the second-stage Roots pump and the first-stage Roots pump;

[0033] Step 19: After the vacuum pump, the second-stage Roots pump and the first-stage Roots pump have all stopped, check the remaining volume V1 of the crystallization tank. If the remaining volume V1 is less than the set volume 1, return to the previous step to continue the judgment. If the remaining volume V1 is greater than the set volume 1, proceed to the next step.

[0034] Step 20: Open the vent valve, open the vacuum crystallizer discharge valve, and start the discharge timing;

[0035] Step 21: Once the feeding timer reaches the set feeding duration, the feeding is considered complete;

[0036] Step 22: Close the discharge valve of the vacuum crystallizer;

[0037] Step 23: Stop side stirring; program complete.

[0038] Step 24: Repeat steps 2-23.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] 1) This invention designs an automatic control system, which improves control accuracy and efficiency;

[0041] 2) This invention adds automated equipment to reduce the intensity of manual labor and improve the accuracy of execution; it is easy to operate, highly automated, safe, and stable, and truly realizes the automated control of the process, which not only reduces the intensity of labor but also reduces production costs.

[0042] 3) This invention provides an automatic control method for vacuum crystallization process. The method of this invention is simple, highly automated, safe, and stable. It realizes the automatic control of the entire operation of vacuum crystallization process, realizes one-button start of vacuum crystallization process, realizes automatic control and cycle process of vacuum crystallization process, reduces labor intensity, reduces production costs, and improves production efficiency.

[0043] 4) This invention establishes a calculation model for controlling the amount of material added, the crystallization rate, and the crystallization temperature. By controlling the temperature and time, the cooling rate is calculated in real time. This invention enables precise control of the temperature, material addition, and cooling process in the vacuum crystallization process, avoiding production instability caused by parameter misalignment. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of the present invention.

[0045] Among them, 100-vacuum crystallizer, 110-side agitator, 120-vacuum crystallizer discharge valve, 130-drain valve, 140-vacuum crystallizer feed valve, 150-liquid phase temperature measuring device, 160-demister, 200-titanium liquid tank before crystallization, 210-titanium liquid tank discharge valve before crystallization, 220-vacuum crystallization feed flow meter, 300-spray condenser, 400-hot water exchange tank, 410-crystallization cold water inlet valve, 4 20-Crystallization cold water return valve, 430-Low temperature water circulation pump, 440-Pressure measuring instrument, 450-Water distributor, 500-Unpressurized circulating water tank, 510-Unpressurized crystallization water inlet valve, 520-Unpressurized crystallization water return valve, 530-Cooling water sealing tank, 540-Spray water pump, 600-Vacuum pump, 610-Vacuum pump vent valve, 710-Secondary Roots pump, 720-Primary Roots pump, 800-Post-crystallization storage tank. Detailed Implementation

[0046] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but these descriptions are not intended to limit the invention and are merely illustrative. The advantages of the present invention will become clearer and easier to understand through this description.

[0047] Referring to the accompanying drawings, the automatic control system for vacuum crystallization is characterized by comprising a vacuum crystallization tank 100, a pre-crystallization titanium liquid tank 200, and a spray condenser tank 300; the vacuum crystallization tank 100 has a side stirrer 110 installed on its bottom side, a bottom connection to a vacuum crystallization tank discharge valve 120, a top vent valve 130 installed, and a top connection to the spray condenser tank 300; the vacuum crystallization tank discharge valve 120 is connected to a post-crystallization storage tank 800; the pre-crystallization titanium liquid tank 200 is connected to the bottom of the vacuum crystallization tank 100 sequentially through a pre-crystallization titanium liquid tank discharge valve 210 and a vacuum crystallization tank feed valve 140;

[0048] The top of the spray condenser tank 300 is connected to one end of the hot water exchange tank 400 via a crystallization cold water inlet valve 410, and the bottom is connected to the other end of the hot water exchange tank 400 via a crystallization cold water return valve 420. The top of the spray condenser tank 300 is connected to one end of the pressureless circulating water tank 500 via a crystallization pressureless water inlet valve 510, and the bottom is connected to the other end of the pressureless circulating water tank 500 via a crystallization pressureless water return valve 520. The top side of the spray condenser tank 300 is connected to the vacuum pump 600 via a vacuum pump vent valve 610.

[0049] A liquid phase temperature measuring device 150 is provided on the bottom side of the vacuum crystallizer 100; a vacuum crystallization feed flow meter 220 is provided between the pre-crystallization titanium liquid tank discharge valve 210 and the vacuum crystallizer feed valve 140.

[0050] The top of the vacuum crystallizer 100 is connected to the spray condenser 300 via a demister 160.

[0051] The hot water exchange tank 400 is connected to the crystallization cold water inlet valve 410 in sequence through a low-temperature water circulation pump 430, a pressure measuring device 440, and a water distributor 450.

[0052] The crystallization pressureless water return valve 520 is connected to the pressureless circulating water tank 500 in sequence through the cooling water liquid seal tank 530 and the spray water pump 540.

[0053] The vacuum pump 600 is connected to the vacuum pump vent valve 610 in sequence through a secondary Roots pump 710 and a primary Roots pump 720.

[0054] An automatic control method for a vacuum crystallization automatic control system, characterized by comprising the following steps:

[0055] Step 1: Click "Auto" to reset all timers and the step sequence, and initialize the device;

[0056] Step 2: Start the program, open the vacuum crystallizer feed valve 140, and start the side agitator 110;

[0057] Step 3: Open the discharge valve 210 of the titanium liquid tank before crystallization;

[0058] Step 4: The vacuum crystallization feed flow meter 220 starts to accumulate metering. When the set accumulated flow rate is reached, the titanium liquid tank discharge valve 210 before crystallization is closed, and the vacuum crystallization tank feed valve 140 is closed.

[0059] Step 5: Close the vent valve 130;

[0060] Step 6: Open the vacuum pump vent valve 610 and turn on the vacuum pump 600;

[0061] Step 7: After vacuum pump 600 has been turned on for 120 seconds, close vacuum pump vent valve 610.

[0062] Step 8: After the system vacuum reaches the set vacuum level (≥90 kPa required), start the second-stage Roots pump 710 first, and then start the first-stage Roots pump 720.

[0063] Step 9: When the vacuum degree of the vacuum crystallizer 100 reaches the set vacuum degree, open the crystallization pressureless water return valve 520, while the crystallization cold water inlet valve 410 and the crystallization cold water return valve 420 are in the closed state.

[0064] Step 10: Open the crystallization pressureless water inlet valve 510;

[0065] Step 11: Detect the liquid phase temperature of the vacuum crystallizer 100 by the liquid phase temperature measuring device 150. When the liquid phase temperature reaches the set temperature T1, close the pressureless water inlet valve 510 for crystallization. T1 is the temperature of the titanium liquid when switching between pressureless water spray and cold water spray during the titanium liquid crystallization process. It is mainly determined based on the crystallization cooling rate.

[0066] Step 12: Open the crystallization cold water inlet valve 410 to the set opening degree 1;

[0067] Step 13: Start the cryogenic water circulation pump 430;

[0068] Step 14: Open the crystallization cold water return valve 420 and close the crystallization unpressurized water return valve 520;

[0069] Step 15: When the liquid phase temperature of the vacuum crystallizer 100 reaches the set value T2 of the crystallization point temperature detected by the liquid phase temperature measuring instrument 150, adjust the crystallization cold water inlet valve 410 to the set opening degree 2; T2 is the temperature point at which ferrous iron in the titanium liquid begins to crystallize.

[0070] Step 16: When the liquid phase temperature of the vacuum crystallizer (100) is less than the set value T2 of the crystallization point temperature, and the duration is greater than the set duration 1 (the set duration 1 refers to the nucleation time period of the crystallization nuclei given by the process), adjust the crystallization cold water inlet valve (410) to the set opening degree 1.

[0071] Step 17: When the liquid phase temperature of the vacuum crystallizer 100 reaches the discharge set temperature T3 as detected by the liquid phase temperature measuring instrument 150, close the crystallization cold water inlet valve 410 and the crystallization cold water return valve 420; T3 is the endpoint temperature controlled by the crystallization process, which is mainly determined based on the process control index iron-titanium ratio.

[0072] Step 18: Stop vacuum pump 600; stop secondary Roots pump 710 and primary Roots pump 720;

[0073] Step 19: After the vacuum pump 600, the second-stage Roots pump 710 and the first-stage Roots pump 720 have all stopped, check the remaining volume V1 of the crystallized storage tank 800. If the remaining volume V1 is less than the set volume 1, return to the previous step to continue the judgment. If the remaining volume V1 is greater than the set volume 1, proceed to the next step.

[0074] Step 20: Open the vent valve 130, open the vacuum crystallizer discharge valve 120, and start the discharge timing;

[0075] Step 21: Once the feeding timer reaches the set feeding duration, the feeding is considered complete;

[0076] Step 22: Close the discharge valve 120 of the vacuum crystallizer;

[0077] Step 23: Stop side stirring 110, program complete;

[0078] Step 24: Repeat steps 2-23.

[0079] All other unspecified parts belong to the prior art.

Claims

1. An automatic control system for vacuum crystallization, characterized by: The application relates to a vacuum crystallization device, which comprises a vacuum crystallization tank (100), a pre-crystallization titanium liquid tank (200) and a spray condensing tank (300); the bottom side of the vacuum crystallization tank (100) is provided with a side stirring device (110), the bottom is connected with a vacuum crystallization tank discharge valve (120), the top is provided with a discharge valve (130), and the top is connected with the spray condensing tank (300); the vacuum crystallization tank discharge valve (120) is connected with a post-crystallization storage tank (800); the pre-crystallization titanium liquid tank (200) is sequentially connected with the vacuum crystallization tank (100) through a pre-crystallization titanium liquid tank discharge valve (210) and a vacuum crystallization tank feeding valve (140); The top of the spray condensing tank (300) is connected with one end of a heat exchange water tank (400) through a crystallization cold water inlet valve (410), the bottom is connected with the other end of the heat exchange water tank (400) through a crystallization cold water return valve (420), the top of the spray condensing tank (300) is connected with one end of a non-pressure circulating water pool (500) through a crystallization non-pressure water inlet valve (510), the bottom is connected with the other end of the non-pressure circulating water pool (500) through a crystallization non-pressure water return valve (520), and the top side of the spray condensing tank (300) is connected with a vacuum pump (600) through a vacuum pump discharge valve (610).

2. The automatic vacuum crystallization control system of claim 1, wherein: The bottom side of the vacuum crystallization tank (100) is provided with a liquid phase temperature measurer (150); a vacuum crystallization feeding flowmeter (220) is arranged between the pre-crystallization titanium liquid tank discharge valve (210) and the vacuum crystallization tank feeding valve (140).

3. The automatic vacuum crystallization control system of claim 1, wherein: The top of the vacuum crystallization tank (100) is connected with the spray condensing tank (300) through a defoaming device (160).

4. The automatic vacuum crystallization control system of claim 1, wherein: The heat exchange water tank (400) is sequentially connected with the crystallization cold water inlet valve (410) through a low-temperature water circulating pump (430), a pressure measurer (440) and a water distributor (450).

5. The automatic vacuum crystallization control system of claim 1, wherein: The crystallization non-pressure water return valve (520) is sequentially connected with the non-pressure circulating water pool (500) through a cooling water liquid seal tank (530) and a spray water pump (540).

6. The automatic vacuum crystallization control system of claim 1, wherein: The vacuum pump (600) is sequentially connected with the vacuum pump discharge valve (610) through a secondary Roots pump (710) and a primary Roots pump (720).

7. An automatic control method of a vacuum crystallization automatic control system, characterized by, The application further discloses a vacuum crystallization method, which comprises the following steps: Step 1: click automatic, clear all timers, clear step sequence, and initialize the equipment; Step 2: start the program, open the vacuum crystallization tank feeding valve (140), and start the side stirring device (110); Step 3: open the pre-crystallization titanium liquid tank discharge valve (210); Step 4: the vacuum crystallization feeding flowmeter (220) starts to accumulate measurement, reaches the set accumulated flow, closes the pre-crystallization titanium liquid tank discharge valve (210), and closes the vacuum crystallization tank feeding valve (140); Step 5: close the discharge valve (130); Step 6: open the vacuum pump discharge valve (610) and start the vacuum pump (600); Step 7: after the vacuum pump (600) is started for 120 seconds, the vacuum pump discharge valve (610) is closed; Step 8: after the system vacuum degree reaches the set vacuum degree, start the secondary Roots pump (710) first, and then start the primary Roots pump (720). Step 9: Open the crystallization unpressurized water return valve (520), while the crystallization cold water inlet valve (410) and the crystallization cold water return valve (420) are closed; Step 10: Open the crystallization pressureless water inlet valve (510); Step 11: When the liquid phase temperature of the vacuum crystallizer (100) reaches the set temperature T1 by the liquid phase temperature measuring instrument (150), close the crystallization pressureless water inlet valve (510); Step 12: Open the crystallization cold water inlet valve (410) to the set opening degree 1; Step 13: Start the cryogenic water circulation pump (430); Step 14: Open the crystallization cold water return valve (420) and close the crystallization unpressurized water return valve (520); Step 15: When the liquid phase temperature of the vacuum crystallizer (100) reaches the set value T2 of the crystallization point temperature by the liquid phase temperature measuring instrument (150), adjust the crystallization cold water inlet valve (410) to the set opening degree 2. Step 16: When the liquid phase temperature of the vacuum crystallizer (100) is less than the set value of the crystallization point temperature T2, and the duration is greater than the set duration 1, adjust the crystallization cold water inlet valve (410) to the set opening degree 1. Step 17: When the liquid phase temperature of the vacuum crystallizer (100) reaches the discharge set temperature T3 by the liquid phase temperature measuring instrument (150), close the crystallization cold water inlet valve (410) and close the crystallization cold water return valve (420). Step 18: Stop the vacuum pump (600); stop the second-stage Roots pump (710) and the first-stage Roots pump (720); Step 19: After the vacuum pump (600), the second-stage Roots pump (710) and the first-stage Roots pump (720) have all stopped, check the remaining volume V1 of the crystallized storage tank (800). If the remaining volume V1 < the set volume 1, return to the previous step to continue the judgment. If the remaining volume V1 > the set volume 1, proceed to the next step. Step 20: Open the vent valve (130), open the vacuum crystallizer discharge valve (120), and start the discharge timing; Step 21: Once the feeding timer reaches the set feeding duration, the feeding is considered complete; Step 22: Close the discharge valve (120) of the vacuum crystallizer; Step 23: Stop side stirring (110), program complete; Step 24: Repeat steps 2-23.

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