Full-automatic control system for vinylene carbonate crystallization process

Abstract

The utility model belongs to the technical field of vinylene carbonate production, and particularly relates to a full-automatic control system for a vinylene carbonate crystallization process. Comprising a primary crystallization module, a secondary crystallization module and a temperature control module, wherein the primary crystallization module is used for primary crystallization, primary sweating and primary melting processes of a vinylene carbonate semi-finished product; the secondary crystallization module is connected with the primary crystallization module; the secondary crystallization module is used for carrying out secondary crystallization, secondary sweating and secondary melting processes on the vinylene carbonate solution output by the primary crystallization module; the temperature control module is connected with the primary crystallization module and the secondary crystallization module, and the temperature control module provides temperature control water for each technological process for the primary crystallization module and the secondary crystallization module respectively. According to the utility model, the automatic operation of the system can be realized, qualified products can be produced, and DCS operators only need to monitor, find abnormal alarms and process in time, so that the working efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of vinylene carbonate production, in particular to a fully automatic control system for vinylene carbonate crystallization process. Background Art

[0002] The semi-finished vinylene carbonate produced by the distillation unit has a content of approximately 99.5%, and needs to be purified to 99.999% through a crystallization process. The crystallization process involves many pieces of equipment and complex operating steps, requiring high proficiency from DCS operators. Once an operation error occurs, it may lead to problems such as unqualified products or low yields. The temperature of the vinylene carbonate material is relatively low during the crystallization process. When the ambient temperature is below 15 degrees for a long time, the vinylene carbonate in the equipment and pipelines is prone to solidification, resulting in abnormal operation. At the same time, if the temperature of the vinylene carbonate is above 45 degrees for a long time, it is easy to cause discoloration, making the product unqualified, so a temperature-controlled heating method is required. The temperature of the boiling water tank is kept constant at 35-40 degrees, which can meet the heating requirements of this set of crystallization process equipment and pipelines.

[0003] Existing DCS operators operate manually. The entire crystallization process is long, involving many pieces of equipment, and a greater number of regulating valves, shut-off valves, and instrument display data. During manual operation, DCS operators need to frequently adjust according to the data while also controlling each process node. Otherwise, problems such as unqualified products or low yields will occur, requiring extremely high operator proficiency. Traditional crystallizers use a one-in-one-out method, with water entering the shell at the bottom and exiting at the top. During dynamic crystallization, vinylene carbonate enters the crystallizer tube from the top and exits from the bottom, resulting in uneven temperature distribution during crystallization, with high temperatures at the top and low temperatures at the bottom. This makes it easier for impurities to accumulate at the bottom of the crystallizer during crystallization. During the sweating process, the temperature of the sweating water inlet area at the bottom of the crystallizer is high. After heat exchange in the crystallizer, the water outlet temperature at the top is low, causing excessive sweating of vinylene carbonate at the bottom of the crystallizer, affecting product yield. Utility Model Content

[0004] In view of the above problems, the purpose of the present invention is to provide a fully automatic control system for the vinylene carbonate crystallization process, which can realize fully automatic operation, reduce the dependence on skilled DCS operators, and stably produce qualified products.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides a fully automatic control system for vinylene carbonate crystallization process, comprising:

[0007] Primary crystallization module, used for primary crystallization, primary sweating and primary melting of vinylene carbonate semi-finished products;

[0008] The secondary crystallization module is connected to the primary crystallization module, and is used to perform secondary crystallization, secondary sweating and secondary melting processes on the vinylene carbonate solution output from the primary crystallization module;

[0009] The temperature control module is connected to the primary crystallization module and the secondary crystallization module, and provides temperature-controlled water for each process for the primary crystallization module and the secondary crystallization module respectively.

[0010] The primary crystallization module includes a primary raw material tank, a primary sweat tank and a primary crystallizer, wherein the shell of the primary crystallizer is a primary crystallization sandwich temperature control structure, and the primary crystallization sandwich temperature control structure is connected to the temperature control module;

[0011] The bottom of the primary crystallizer is connected to the primary raw material tank, the primary sweat tank and the secondary crystallization module through three branch pipelines, and each branch pipeline is provided with a control valve; the primary sweat tank is connected to the primary raw material feed port of the primary raw material tank through a primary sweat pump and a pipeline, and the primary raw material feed port is also connected to the vinylene carbonate semi-finished product feed line. The primary raw material tank is connected to the top of the primary crystallizer and the upstream distillation unit through a primary raw material circulation pump and a primary crystallization circulation pipeline, and each pipeline is provided with a control valve.

[0012] The secondary crystallization module includes a secondary raw material tank, a secondary sweat tank, a melting tank and a secondary crystallizer, wherein the shell of the secondary crystallizer is a secondary crystallization sandwich temperature control structure, and the secondary crystallization sandwich temperature control structure is connected to the temperature control module;

[0013] The bottom of the secondary crystallizer is connected to the secondary raw material tank, secondary sweat tank and melting tank through three branch pipelines respectively, and each branch pipeline is provided with a control valve; the secondary raw material tank is connected to the top of the secondary crystallizer through a secondary raw material circulation pump and a secondary raw material circulation pipeline, the secondary sweat tank is connected to the primary raw material tank through a secondary sweat pump and a pipeline, and the melting tank is connected to the finished product line through a melting pump.

[0014] The temperature control structure of the primary crystallization interlayer of the primary crystallizer is the same as the temperature control structure of the secondary crystallization interlayer of the secondary crystallizer, both of which include multiple sections of jackets with independent cavities arranged in sequence along the height direction. The inlet and outlet of each section of the jacket are respectively provided with a temperature sensor and an automatic regulating valve, and the value displayed by the temperature sensor is linked to the opening of the automatic regulating valve for interlocking control.

[0015] The primary raw material tank is provided with a raw material tank weighing module for weighing the raw materials; the secondary raw material tank is provided with a secondary raw material tank weighing module for weighing the secondary raw materials.

[0016] The temperature control module includes a chilled water control module, a sweating water control module and a boiling water control module;

[0017] The primary crystallizer is connected with the chilled water control module, sweating water control module and boiled water control module to form a primary chilled water circulation system, primary sweating water circulation system and primary boiled water circulation system.

[0018] The secondary crystallizer is connected with the chilled water control module, sweating water control module and boiled water control module to form a secondary chilled water circulation system, secondary sweating water circulation system and secondary boiled water circulation system.

[0019] The return pipeline of the primary crystallizer and the secondary crystallizer is connected with the compressed air pipeline to return the chilled water, sweating water and boiled water through compressed air.

[0020] The chilled water control module comprises a chilled water tank and a chilled water pump, wherein the water inlet of the chilled water pump is connected with the bottom of the chilled water tank, the water outlet of the chilled water pump is connected with the top of the chilled water tank, the primary crystallizer, the secondary crystallizer and the return water main through multiple branch pipelines, and each branch pipeline is provided with a control valve; the primary crystallizer and the secondary crystallizer are connected with the top of the chilled water tank through the chilled water return pipeline; and the top of the chilled water tank is connected with the 10℃ water inlet pipeline.

[0021] The sweating water control module comprises a sweating water tank and a sweating water pump, wherein the water inlet of the sweating water pump is connected with the bottom of the sweating water tank through a pipeline, the water outlet of the sweating water pump is connected with the top of the sweating water tank, the primary crystallizer and the secondary crystallizer through multiple branch pipelines, and each branch pipeline is provided with a control valve; the primary crystallizer and the secondary crystallizer are connected with the top of the sweating water tank through the sweating water return pipeline; and the top of the sweating water tank is connected with the process water inlet pipeline.

[0022] The boiled water control module comprises a boiled water tank and a boiled water pump, wherein the water inlet of the boiled water pump is connected with the bottom of the boiled water tank, the water outlet of the boiled water pump is connected with the top of the boiled water tank, the primary crystallizer and the secondary crystallizer through multiple branch pipelines, and each branch pipeline is provided with a control valve; the primary crystallizer and the secondary crystallizer are connected with the top of the boiled water tank through the boiled water return pipeline; and the top of the boiled water tank is connected with the process water inlet pipeline.

[0023] The temperature of the chilled water is 17-18℃, the temperature of the sweating water is 20-22℃, and the temperature of the boiled water is 35-40℃.

[0024] The advantages and beneficial effects of the present invention are as follows: The present invention provides a fully automatic control system for the vinylene carbonate crystallization process, enabling automatic system operation and producing qualified products. DCS operators only need to monitor the system and promptly address any abnormalities. The temperature difference between the chilled water, sweating water, and boiled water in the crystallizer is significant, requiring compressed air to return the water to the water tank after each use. Simultaneous freezing and crystallization within the crystallizer requires a significant amount of water, approximately 25 cubic meters per crystallizer. This control scheme utilizes a chilled water tank with sufficient capacity to cool only one crystallizer, with the remaining water being transferred from a 10-degree Celsius water storage tank used by the utility. While the chilled water tank temperature is controlled at 17-18 degrees Celsius, the public utility water source is 10-degree Celsius. Automatic temperature control allows for this transfer, significantly reducing the space occupied by the chilled water tanks in the workshop and the manufacturing cost of the chilled water tanks. The three water tanks are top-fed, primarily to keep them away from the suction port of the bottom pump, resulting in better mixing during water intake and more stable temperature during pump delivery.

[0025] The crystallizer of the utility model adopts a four-section shell structure, and the water inlet of each section is controlled separately, so that the temperature distribution of the upper and lower parts of the crystallizer is kept as uniform as possible during crystallization and sweating, which significantly improves the product processing efficiency and yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a fully automatic control system for a vinylene carbonate crystallization process according to the present invention;

[0027] Figure 2 This is a schematic structural diagram of the primary crystallization module in the present invention;

[0028] Figure 3 This is a schematic structural diagram of the secondary crystallization module in the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the chilled water control module in the present utility model;

[0030] Figure 5 This is a structural diagram of the sweat control module in the present invention;

[0031] Figure 6 This is a structural diagram of the Sinochem boiling water control module of the present utility model.

[0032] In the figure: 1-feed shut-off valve, 2-primary raw material tank, 3-raw material tank weighing module, 4-primary raw material circulation pump, 5-primary crystallizer feed regulating valve, 6-primary crystallizer inlet flow meter, 7-chilled water pump, 8-chilled water tank circulation regulating valve, 9-chilled water pump outlet pressure gauge, 10-chilled water tank thermometer, 11-chilled water tank steam regulating valve, 12-chilled water tank level gauge, 13-chilled water tank, 14-export regulating valve, 15-chilled water tank inlet regulating valve, 16-primary crystallization chilled water return shut-off valve, 17-primary crystallization drain shut-off valve, 18-primary crystallization chilled water inlet shut-off valve, 19-chilled water return regulating valve, 20-primary crystallization total inlet regulating valve, 21-sampling point, 22-primary crystallization inlet Water regulating valve a, 23-primary crystallization water inlet regulating valve b, 24-primary crystallization water inlet regulating valve c, 25-primary crystallization water inlet regulating valve d, 26-primary crystallizer thermometer a, 27-primary crystallizer thermometer b, 28-primary crystallizer thermometer c, 29-primary crystallizer thermometer d, 30-10 degree water return regulating valve, 31-chilled water tank inlet flowmeter, 32-10 degree water return flowmeter, 33-primary raw material tank circulation shut-off valve, 34-return upstream distillation unit shut-off valve, 35-chilled water return flowmeter, 36-primary crystallizer compressed air inlet shut-off valve, 37-primary crystallizer compressed air inlet flowmeter, 38-chilled water tank on-site vent line, 39-sweating water tank, 40-process water inlet regulating valve a, 41-sweating water tank level gauge, 42-10-degree water supply regulating valve, 43-sweating water tank steam regulating valve, 44-sweating water tank thermometer, 45-sweating water pump, 46-sweating water pump outlet pressure gauge, 47-sweating water circulation regulating valve, 48-primary sweating tank feed cut-off valve, 49-primary crystallization sweating inlet cut-off valve, 50-primary crystallization sweating return water cut-off valve, 51-primary crystallization return water main valve, 52-primary crystallization secondary line cut-off valve, 53-primary crystallization inlet flowmeter, 54-primary sweating tank, 55-primary sweating tank weighing module, 56-primary sweating pump, 57-primary sweating pump outlet cut-off valve, 58-process water inlet regulating valve b, 59-boiling water tank level gauge, 60-boiling water tank thermometer, 61 -Steam regulating valve for boiling water tank, 62-boiling water tank, 63-boiling water pump, 64-boiling water pump outlet pressure gauge, 65-boiling water return regulating valve, 66-primary crystallizer boiling water inlet shut-off valve, 67-primary crystallization return water shut-off valve, 68-boiling water tank on-site venting line, 69-secondary raw material tank, 70-secondary raw material tank weighing module, 71-secondary sweat tank, 72-secondary sweat tank weighing module, 73-primary crystallization discharge shut-off valve, 74-secondary raw material circulation pump, 75-secondary crystallizer feed regulating valve, 76-secondary crystallization circulation shut-off valve, 77-secondary crystallizer air inlet flowmeter, 78-delivery shut-off valve, 79-secondary crystallizer compressed air inlet flowmeter, 80-secondary crystallizer compressed air inlet shut-off valve,81-Secondary crystallization chilled water return cut-off valve, 82-Secondary crystallization sweating return cut-off valve, 83-Secondary crystallization return cut-off valve, 84-Secondary crystallization return cut-off valve, 85-Secondary crystallizer thermometer a, 86-Secondary crystallization inlet regulating valve a, 87-Secondary crystallizer thermometer b, 88-Secondary crystallization inlet regulating valve b, 89-Secondary crystallizer thermometer c, 90-Secondary crystallization inlet regulating valve c, 91-Secondary crystallizer thermometer d, 92-Secondary crystallization inlet regulating valve d, 93-Secondary crystallization drain cut-off valve, 94-Secondary crystallization total water inlet regulating valve, 95-Secondary crystallizer outlet Material shut-off valve, 96-secondary sweat tank feed shut-off valve, 97-secondary crystallizer melt water inlet shut-off valve, 98-secondary crystallization sweat water inlet shut-off valve, 99-secondary crystallization auxiliary line shut-off valve, 100-secondary sweat pump outlet shut-off valve, 101-secondary sweat pump, 102-melting tank, 103-melting tank weighing module, 104-melting pump, 105-equipment pipeline, 106-heating circulation pump, 107-sweating water tank on-site vent line, 108-primary crystallizer, 109-secondary crystallizer, 110-secondary crystallization water inlet flowmeter, 111-secondary crystallization chilled water inlet shut-off valve. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] See also Figures 1 to 6 As shown, the utility model provides a fully automatic control system for vinylene carbonate crystallization process, comprising a primary crystallization module, a secondary crystallization module and a temperature control module, wherein the primary crystallization module is used for the primary crystallization, primary sweating and primary melting process of the vinylene carbonate semi-finished product; the secondary crystallization module is connected to the primary crystallization module, and the secondary crystallization module is used to perform secondary crystallization, secondary sweating and secondary melting process on the vinylene carbonate solution output by the primary crystallization module; the temperature control module is connected to the primary crystallization module and the secondary crystallization module, and the temperature control module provides temperature-controlled water for each process for the primary crystallization module and the secondary crystallization module respectively.

[0035] See also Figure 1 、 Figure 2As shown, in the embodiment of the present invention, the primary crystallization module includes a primary raw material tank 2, a primary sweat tank 54 and a primary crystallizer 108, wherein the shell of the primary crystallizer 108 is a primary crystallization interlayer temperature control structure, and the primary crystallization interlayer temperature control structure is connected to the temperature control module; the bottom of the primary crystallizer 108 is connected to the primary raw material tank 2, the primary sweat tank 54 and the secondary crystallization module through three branch pipelines respectively, and each branch pipeline is provided with a primary raw material tank circulation shut-off valve 33, a primary sweat tank feed shut-off valve 48 and a primary crystallization discharge shut-off valve 73 in sequence; the primary sweat tank 54 is connected to the primary raw material feed port of the primary raw material tank 2 through a primary sweat pump 56, a primary sweat pump outlet shut-off valve 57 and a pipeline, and the primary raw material feed port is also connected to the vinylene carbonate semi-finished product feed line, and the vinylene carbonate semi-finished product feed line is provided with a feed shut-off valve 1. The primary raw material tank 2 is connected to the top of the primary crystallizer 108 and the upstream distillation unit through the primary raw material circulation pump 4 and the primary crystallization circulation pipeline. The primary crystallization circulation pipeline is provided with a primary crystallizer air inlet flowmeter 6 and a primary crystallizer feed regulating valve 5. The pipeline connected to the upstream distillation unit is provided with a return upstream distillation unit shut-off valve 34.

[0036] Furthermore, the primary raw material tank 2 is provided with a raw material tank weighing module 3 for weighing the raw materials. The primary sweat tank 54 is provided with a primary sweat tank weighing module 55 for weighing the sweat.

[0037] See also Figure 3 As shown, in an embodiment of the present invention, the secondary crystallization module includes a secondary raw material tank 69, a secondary liquid tank 71, a melting tank 102, and a secondary crystallizer 109. The shell of the secondary crystallizer 109 is a secondary crystallization interlayer temperature control structure, which is connected to the temperature control module. The bottom of the secondary crystallizer 109 is connected to the secondary raw material tank 69, the secondary liquid tank 71, and the melting tank 102 via three branch pipelines, each of which is respectively equipped with a secondary crystallization circulation shut-off valve 76, a secondary liquid tank feed shut-off valve 96, and a secondary crystallization discharge shut-off valve 95. The front end of the secondary liquid tank feed shut-off valve 96 is provided with a sampling point 21. The secondary raw material tank 69 is connected to the top of the secondary crystallizer 109 via a secondary raw material circulation pump 74 and a secondary raw material circulation pipeline. The secondary raw material circulation pipeline is equipped with a secondary crystallizer air inlet flowmeter 77 and a secondary crystallizer feed regulating valve 75. Secondary sweat tank 71 is connected to primary raw material tank 2 via secondary sweat pump 101, secondary sweat pump outlet shut-off valve 100, and piping. This piping is connected to the secondary raw material circulation pipeline via a bypass line and delivery shut-off valve 78. Demolition tank 102 is connected to the finished product line via demolition pump 104 and is also equipped with a demolition tank weighing module 103.

[0038] Furthermore, the secondary raw material tank 69 is provided with a secondary raw material tank weighing module 70 for weighing the secondary raw material, the secondary sweat tank 71 is provided with a secondary sweat tank weighing module 72, and the melting tank 102 is provided with a melting tank weighing module 103.

[0039] In the embodiment of the present invention, the temperature control structure of the primary crystallization interlayer of the primary crystallizer 108 is the same as the temperature control structure of the secondary crystallization interlayer of the secondary crystallizer 109, both of which include multiple sections of jackets with independent cavities arranged in sequence along the height direction, and the inlet and outlet of each section of the jacket are respectively provided with a temperature sensor and an automatic regulating valve, and the value displayed by the temperature sensor is linked to the opening of the automatic regulating valve for interlocking control.

[0040] Specifically, see Figure 2 As shown, both the primary crystallization interlayer temperature control structure and the secondary crystallization interlayer temperature control structure are equipped with four jackets. The water inlets of the four jackets of the primary crystallization interlayer temperature control structure are equipped, from top to bottom, with primary crystallization water inlet regulating valves a22, b23, c24, and d25, respectively. These valves a22, b23, c24, and d25 are connected in parallel to the main water inlet pipeline and the return water main. The main water inlet pipeline is equipped with a primary crystallization main water inlet regulating valve 20 and a primary crystallization water inlet flowmeter 53. The return water main is equipped with a primary crystallization drain shut-off valve 17. The main water inlet pipeline and the return water main are connected via a primary crystallization secondary line shut-off valve 52. The four jackets are equipped with primary crystallizer thermometers a26, b27, c28, and d29, respectively, from top to bottom. The recovery ports of the four jackets are connected in parallel to the primary crystallization return line, which is connected to the primary crystallization return water main valve 51.

[0041] Specifically, see Figure 3As shown, the four-section jacket of the secondary crystallization interlayer temperature control structure is provided with secondary crystallizer thermometer a85, secondary crystallizer thermometer b87, secondary crystallizer thermometer c89 and secondary crystallizer thermometer d91 from top to bottom; the water inlet of the four-section jacket of the secondary crystallization interlayer temperature control structure is provided with secondary crystallization water inlet regulating valve a86, secondary crystallization water inlet regulating valve b88, secondary crystallization water inlet regulating valve c90 and secondary crystallization water inlet regulating valve d92 from top to bottom, the secondary crystallization water inlet regulating valve a86, secondary crystallization water inlet regulating valve b88, secondary crystallization water inlet regulating valve c90 and secondary crystallization water inlet regulating valve d92 are connected in parallel to the secondary crystallization main water inlet pipeline, and the secondary crystallization main water inlet pipeline is provided with a secondary crystallization main water inlet regulating valve 94 and a secondary crystallization water inlet flowmeter 110. The return ports of the four jackets are connected in parallel to the secondary crystallization return line, which is connected to the temperature control module and the compressed air line. A secondary crystallization return water shut-off valve 84 is installed on the secondary crystallization return line. The secondary crystallization main water inlet line is connected to the secondary crystallization return line via a secondary crystallization secondary line shut-off valve 99 and a pipeline. The secondary compressed air line is equipped with a secondary crystallizer compressed air inlet flowmeter 79 and a secondary crystallizer compressed air inlet shut-off valve 80.

[0042] See also Figures 1 to 6 As shown, in an embodiment of the present invention, the temperature control module includes a chilled water control module, a sweating water control module and a boiled water control module, the primary crystallizer 108 is connected to the chilled water control module, the sweating water control module and the boiled water control module to form a primary chilled water circulation system, a primary sweating water circulation system and a primary boiled water circulation system; the secondary crystallizer 109 is connected to the chilled water control module, the sweating water control module and the boiled water control module to form a secondary chilled water circulation system, a secondary sweating water circulation system and a secondary boiled water circulation system; the return pipelines of the primary crystallizer 108 and the secondary crystallizer 109 are connected to the compressed air pipeline, and the chilled water, sweating water and boiled water are pressed back by compressed air.

[0043] See also Figure 1 、 Figure 4As shown, in an embodiment of the present invention, the chilled water control module includes a chilled water tank 13 and a chilled water pump 7, wherein the water inlet of the chilled water pump 7 is connected to the bottom of the chilled water tank 13, and the water outlet of the chilled water pump 7 is connected to the top of the chilled water tank 13, the primary crystallizer 108, the secondary crystallizer 109 and the return water main through multiple branch pipelines, each branch pipeline is provided with a control valve, and a chilled water pump outlet pressure gauge 9 is provided at the water outlet of the chilled water pump 7; the primary crystallizer 108 and the secondary crystallizer 109 are connected to the top of the chilled water tank 13 through a chilled water return pipeline, and a chilled water return regulating valve 19 and a chilled water return flowmeter 35 are provided on the chilled water return pipeline, and the chilled water return pipeline is connected to the 10℃ return water main through a 10-degree water return flowmeter 32 and a 10-degree water return regulating valve 30. The top of the chilled water tank 13 is connected to a 10°C water inlet pipeline, which is equipped with a chilled water tank inlet flowmeter 31 and a chilled water tank inlet regulating valve 15. The top of the chilled water tank 13 is also equipped with a chilled water tank level gauge 12 and a chilled water tank on-site vent line 38. The bottom of the chilled water tank 13 is equipped with a chilled water tank thermometer 10 and a chilled water tank steam regulating valve 11.

[0044] Specifically, a chilled water tank circulation regulating valve 8 is installed on the circulation pipeline between the outlet of the chilled water pump 7 and the top of the chilled water tank 13. A delivery regulating valve 14 is installed on the pipeline connecting the outlet of the chilled water pump 7 to the 10°C return water main. A primary crystallization chilled water inlet shut-off valve 18 and a secondary crystallization chilled water inlet shut-off valve 111 are installed on the pipeline connecting the outlet of the chilled water pump 7 to the primary crystallizer 108 and the secondary crystallizer 109, respectively. A primary crystallization chilled water return shut-off valve 16 and a secondary crystallization chilled water return shut-off valve 81 are installed on the chilled water return pipeline connecting the primary crystallizer 108 and the secondary crystallizer 109, respectively.

[0045] See also Figure 1 、 Figure 5 As shown, in an embodiment of the present invention, the sweating water control module includes a sweating water tank 39 and a sweating water pump 45, wherein the water inlet of the sweating water pump 45 is connected to the bottom of the sweating water tank 39 through a pipeline, and the water outlet of the sweating water pump 45 is connected to the top of the sweating water tank 39, the primary crystallizer 108 and the secondary crystallizer 109 through multiple branch pipelines, each branch pipeline is provided with a control valve, and a sweating water pump outlet pressure gauge 46 is provided at the water outlet of the sweating water pump 45; the primary crystallizer 108 and the secondary crystallizer 109 are connected to the top of the sweating water tank 39 through the sweating water return pipeline; the top of the sweating water tank 39 is connected to the process water inlet pipeline, and the process water inlet pipeline is provided with a process water inlet regulating valve a40. A sweating water tank level gauge 41 and a sweating water tank on-site vent line 107 are provided on the top of the sweating water tank 39, and a sweating water tank thermometer 44, a 10-degree water supply regulating valve 42 and a sweating water tank steam regulating valve 43 are provided at the bottom of the sweating water tank 39.

[0046] Specifically, a sweating water circulation regulating valve 47 is provided on the circulation pipeline between the water outlet of the sweating water pump 45 and the top of the sweating water tank 39. A primary crystallization sweating water inlet shut-off valve 49 and a secondary crystallization sweating water inlet shut-off valve 98 are provided on the sweating water inlet pipeline connecting the water outlet of the sweating water pump 45 to the primary crystallizer 108 and the secondary crystallizer 109, respectively. A primary crystallization sweating water return shut-off valve 50 and a secondary crystallization sweating water return shut-off valve 82 are provided on the sweating water return pipeline connecting the primary crystallizer 108 and the secondary crystallizer 109, respectively.

[0047] See also Figure 1 、 Figure 6 As shown, in an embodiment of the present invention, the boiling water control module includes a boiling water tank 62 and a boiling water pump 63, wherein the water inlet of the boiling water pump 63 is connected to the bottom water outlet of the boiling water tank 62, and the water outlet of the boiling water pump 63 is connected to the top of the boiling water tank 62, the primary crystallizer 108 and the secondary crystallizer 109 through multiple branch pipelines, each branch pipeline is provided with a control valve, and a boiling water pump outlet pressure gauge 64 is provided at the water outlet of the boiling water pump 63; the primary crystallizer 108 and the secondary crystallizer 109 are connected to the top of the boiling water tank 62 through the boiling water return pipeline; the top of the boiling water tank 62 is connected to the process water inlet pipeline, and the process water inlet pipeline is provided with a process water inlet regulating valve b58. The top of the boiling water tank 62 is also provided with a boiling water tank level gauge 59 and a boiling water tank on-site vent line 68, and the lower part of the boiling water tank 62 is provided with a boiling water tank thermometer 60 and a boiling water tank steam regulating valve 61.

[0048] Furthermore, the bottom water outlet of the boiling water tank 62 is connected to the top of the boiling water tank 62 through a heat-tracing circulation pump 106 and an equipment pipeline 105. A boiling water return regulating valve 65 is provided on the circulation pipeline between the water outlet of the boiling water pump 63 and the top of the boiling water tank 62. A primary crystallizer boiling water inlet shut-off valve 66 and a secondary crystallizer boiling water inlet shut-off valve 97 are provided on the boiling water inlet pipeline between the water outlet of the boiling water pump 63 and the primary crystallizer 108 and the secondary crystallizer 109, respectively. A primary crystallizer return water shut-off valve 67 and a secondary crystallizer return water shut-off valve 83 are provided on the pipeline connecting the boiling water return pipeline to the primary crystallizer 108 and the secondary crystallizer 109, respectively.

[0049] Specifically, the temperature of frozen water is 17-18°C, the temperature of sweating water is 20-22°C, and the temperature of boiling water is 35-40°C.

[0050] In the embodiment of the present invention, all shut-off valves have a switch signal feedback function and a timer alarm function after the partial shut-off valve is opened. All shut-off valve commands need to receive a feedback signal, otherwise an alarm is triggered. The timing function is triggered when the partial shut-off valve is opened. If it is not closed after the set time, the timeout alarm function is triggered. When an alarm is found, the operator promptly confirms the cause of the abnormality. This system is explained using a primary crystallizer and a secondary crystallizer as an example. In reality, it can be a combination of many crystallizers. The control system is more complex, but the principle is the same.

[0051] The utility model provides a fully automatic control system for vinylene carbonate crystallization process, the working principle of which is:

[0052] Primary raw material circulation process: Click the system start button on the operation interface. The system automatically detects the raw material quantity in the upstream vinylene carbonate semi-finished product storage tank. When it exceeds 35 tons, the system automatically opens the feed shut-off valve 1 and feeds the primary raw material tank 2. The feed weight is displayed on the raw material tank weighing module 3. When the displayed value reaches 30 tons, the system automatically closes the feed shut-off valve 1. The system automatically detects the closing signal of the feed shut-off valve 1 and the value displayed on the raw material tank weighing module 3 is not changing. Then, the next instruction is issued to open the primary raw material tank circulation shut-off valve 33 and start the primary raw material circulation pump 4. The system automatically detects the operating current of the pump. During the stage of excessive starting current, the primary crystallizer feed regulating valve 5 is closed. After the current stabilizes for 3 seconds, the primary crystallizer feed regulating valve 5 gradually opens automatically to 35% opening. When the opening is reached, it automatically links to the data displayed by the primary crystallizer inlet flowmeter 6. The set value is 18 t / h. The primary crystallizer feed regulating valve 5 automatically stabilizes at around 18 t / h based on the value displayed by the primary crystallizer inlet flowmeter 6.

[0053] Chilled water tank startup process: After the raw material circulation pump 4 has been running stably for 1 minute, the system automatically detects the reading of the chilled water tank level gauge 12. When the reading is lower than 20%, the chilled water tank inlet regulating valve 15 of 10-degree water is automatically opened; when the reading of the chilled water tank level gauge 12 reaches 20%, an instruction to start the chilled water pump 7 is issued. After the machine pump current stabilizes for 3 seconds, the chilled water tank circulation regulating valve 8 gradually opens automatically to 50% opening. When the opening is reached, it is automatically linked to the chilled water pump outlet pressure gauge 9, and the displayed data setting value is 0.5 MPa. The chilled water tank circulation regulating valve 8 is automatically controlled. The system automatically detects the status of the chilled water tank 13. When the chilled water tank thermometer 10 is between 17 and 18 degrees, the chilled water tank steam regulating valve 11 is always in automatic status. When the temperature is lower than 17 degrees, the chilled water tank steam regulating valve 11 is automatically opened. When the temperature reaches 17 degrees, the chilled water tank steam regulating valve 11 is closed. If the temperature exceeds 18 degrees, the system automatically detects the display of the chilled water tank level gauge 12. When it is lower than 80%, the chilled water tank water inlet regulating valve 15 is opened to replenish water to the chilled water tank 13. At this time, the temperature adjustment and water replenishment valve position is limited to 20% at the maximum. When the chilled water tank thermometer 10 shows that it reaches 18 degrees, the water replenishment is stopped. If the chilled water tank level gauge 12 reaches 80% and the chilled water tank thermometer 10 has not yet exceeded 18°C, the external flow regulating valve 14 gradually opens fully, and the water output from the chilled water tank 13 exceeds the water inlet. When the temperature reaches 18°C, the external flow regulating valve 14 closes. When the chilled water tank level gauge 12 reaches 80%, the chilled water tank inlet regulating valve 15 closes. Thereafter, the external flow regulating valve 14 remains in the automatic state, and the chilled water tank level gauge 12 opens when it reaches 80%. This way, the chilled water tank thermometer 10 will display between 17-18°C and the chilled water tank level gauge 12 will display 80%. This process only needs to be started during the first batch of material; the system will run continuously thereafter.

[0054] During the primary crystallization process, the system detects normal chilled water operation. This detection condition includes normal operating signals and current readings from chilled water pump 7, and normal operation of the chilled water tank thermometer 10 and chilled water tank level gauge 12. At this point, the primary crystallization instruction begins, sequentially opening the primary crystallization chilled water return shutoff valve 16, the primary crystallization return main valve 51, the primary crystallization chilled water inlet shutoff valve 18, and the chilled water return regulating valve 19. At this point, the chilled water return regulating valve 19 is 100% open. The chilled water return regulating valve 19 setting logic automatically adjusts to 100% when chilled water is being used in the crystallizer. The system automatically opens the primary crystallization main inlet regulating valve 20, automatically controlling the flow rate with the primary crystallization inlet flowmeter 53. The flow rate is set to 30 t / h. Based on multiple manual calibrations, the output valve position of primary crystallization water inlet regulating valve a22 is 85%, the output valve position of primary crystallization water inlet regulating valve b23 is 63%, the output valve position of primary crystallization water inlet regulating valve c24 is 57%, and the output valve position of primary crystallization water inlet regulating valve d25 is 50%. At these valve positions, the vinylene carbonate crystallization rate is relatively fast. At the end of crystallization, the temperatures of primary crystallizer thermometers a26, b27, c28, and d29 in primary crystallizer 108 are similar. Post-melting analysis shows very few crystallized impurities, demonstrating that the output valve positions are optimized for the process under these equipment operating conditions. Because the material temperature in the primary raw material tank 2 is relatively high, generally at 30-40 degrees, the temperature in the chilled water tank 13 will gradually rise during the crystallization cycle. When the chilled water tank thermometer 10 reaches 18 degrees, the system automatically opens the chilled water tank inlet regulating valve 15. At this time, the chilled water tank inlet regulating valve 15 is automatically associated with the chilled water tank thermometer 10, and the set value is 18 degrees. With the entry of 10-degree water, the chilled water tank level will gradually rise; when the chilled water tank level gauge 12 shows that the liquid level reaches 70%, the 10-degree water return valve is opened. The regulating valve 30, the 10-degree water return regulating valve 30 and the 10-degree water return flowmeter 32 are automatically associated, and the chilled water tank inlet regulating valve 15 and the chilled water tank inlet flowmeter 31 are automatically associated. At this time, the system instructs the chilled water tank inlet flowmeter 31 and the 10-degree water return flowmeter 32 to be in an equivalent relationship, the purpose of which is to ensure that the liquid level of the chilled water tank 13 is stable at 70%; at the same time, the chilled water tank inlet flowmeter 31 and the chilled water tank thermometer 10 are automatically associated, the purpose of which is to ensure that the temperature in the chilled water tank 13 is stable at 18 degrees.The chilled water return regulating valve 19 is automatically linked to the chilled water return flowmeter 35. The setpoint logic for the chilled water return regulating valve 19 defaults to 100% when the crystallizer is using chilled water. When the chilled water tank level gauge 12 reaches 70%, another control logic is triggered. This control method automatically detects the crystallization status of the primary and secondary crystallizers and confirms the switch status of the primary crystallizer's chilled water inlet shut-off valve 18 and the secondary crystallizer's chilled water inlet shut-off valve 111. If they are open, the circulation flow rate for one channel is 30 t / h, and for both channels it is 60 t / h. The automatic setpoint for the chilled water return flowmeter 35 is the total circulation flow rate required for the primary and secondary crystallizations minus the value displayed by the chilled water tank inlet flowmeter 31. This ensures stable control of the chilled water tank level. During the primary crystallization process, the material in the primary raw material tank 2 gradually decreases. When the raw material tank weighing module 3 displays a value of 3 t, the primary raw material crystallization is complete. Close the primary crystallizer feed regulating valve 5. Three minutes later, close the primary raw material tank circulation shutoff valve 33 to allow the liquid vinylene carbonate in the crystallizer to flow back into the raw material tank. Open the return upstream distillation unit shutoff valve 34. When the raw material tank weighing module 3 displays a value of 0t, close the return upstream distillation unit shutoff valve 34 and stop the primary raw material circulation pump 4.

[0055] Primary crystallization cooling chilled water process: The system automatically closes the primary crystallization chilled water inlet shut-off valve 18, the primary crystallization total water inlet regulating valve 20 and the primary crystallization chilled water return shut-off valve 16, opens the primary crystallization drain shut-off valve 17, fully opens the primary crystallization water inlet regulating valve a22, the primary crystallization water inlet regulating valve b23, the primary crystallization water inlet regulating valve c24 and the primary crystallization water inlet regulating valve d25, opens the primary crystallizer compressed air inlet shut-off valve 36, pressurizes the chilled water in the primary crystallizer 108 to the 10-degree water storage tank of the public works, and the primary crystallizer compressed air inlet flowmeter 37 displays the inlet flow, and the flow rate is 300Nm when the water is steadily pressed. 3 When the water in the primary crystallizer 108 is drained, the compressed air flow rate will instantly rise to 550Nm 3 / h, at which point the system automatically closes the primary crystallizer compressed air inlet shut-off valve 36, the primary crystallizer drain shut-off valve 17, the primary crystallizer water inlet regulating valves a22, b23, c24, and d25. A chilled water tank on-site vent line 38 is installed at the top of the chilled water tank 13 to prevent overpressure or negative pressure in the chilled water tank 13 during water inlet and outlet.

[0056] Primary Crystallization Sweating Process: The primary crystallization sweating process lasts approximately 16 hours. The volume of the sweating water tank 39 is designed to match the shell-side volume of all system crystallizers, meeting the requirement for simultaneous sweating of the maximum number of crystallizers. During system operation, the system automatically checks the sweating water tank level gauge 41. When the level falls below 30%, the process water inlet regulating valve a40 opens, replenishing water until the level gauge 41 reaches 80%. The process water inlet regulating valve a40 automatically closes, the sweating water pump 45 starts, and the sweating water circulation regulating valve 47 opens. The pressure is automatically controlled by the sweating water pump outlet pressure gauge 46, with a set value of 0.5 MPa to ensure uniform temperature mixing within the subsequent sweating water tank 39. The system automatically checks the reading of the sweating water tank thermometer 44. If it exceeds 22.1°C, the 10°C water supply regulating valve 42 is automatically adjusted. If it falls below 21.9°C, the sweating water tank steam regulating valve 43 is automatically adjusted. To save time controlling the temperature, the system is manually refilled to 80% of the water level before operation. This temperature control program is then activated to maintain the water tank temperature at 22°C. The system automatically detects the level gauge 41 in the sweating water tank. If the level falls below 30%, the system pauses and resumes the program after the crystallizer sweating water has been fully returned. This situation generally does not occur. The system detects that the sweating water tank level gauge 41 is greater than 30%, and the sweating water tank thermometer 44 is at 22±0.1 degrees, and opens the primary sweating tank feed cut-off valve 48, the primary crystallization sweating return water cut-off valve 50, the primary crystallization return water main valve 51 and the primary crystallization sweating water inlet cut-off valve 49; the primary crystallization water inlet regulating valve a 22 valve opening is 30%, the primary crystallization water inlet regulating valve b 23 valve opening is 30%, the primary crystallization water inlet regulating valve c 24 valve opening is 30%, the primary crystallization water inlet regulating valve d 25 valve opening is 30%, and the primary crystallization total water inlet regulating valve 20 is opened. The primary crystallization total water inlet regulating valve 20 is automatically associated with the primary crystallization water inlet flowmeter 53, and the flow rate is set to 15t / h. Under these conditions, the readings on primary crystallizer thermometers a 26, b 27, c 28, and d 29 in primary crystallizer 108 gradually increase. When one of these thermometers reaches 21.6°C, the setting for primary crystallization water inlet flowmeter 53 is changed to 10 t / h. The valve positions of primary crystallization water inlet regulating valve a 22, b 23, c 24, and d 25 are changed to 10% and 2% respectively. Under these conditions, impurities flow into the primary sweat tank 54 along with the sweat. When the reading on the primary sweat tank weighing module 55 reaches 4 t, sweating is complete, and the primary sweat tank feed shut-off valve 48 is closed.Before the next feeding of the primary raw material tank 2, first check the reading of the primary sweat tank weighing module 55. After confirming the presence of sweat, start the primary sweat pump 56, open the primary sweat pump outlet shut-off valve 57, and transport sweat into the primary raw material tank 2. When the reading of the primary sweat tank weighing module 55 is 0, close the primary sweat pump outlet shut-off valve 57, stop the primary sweat pump 56, and use the sweat as the next crystallization raw material.

[0057] The process of sweating water removal in the primary crystallization: the system automatically closes the primary crystallization sweating water inlet cut-off valve 49, closes the primary crystallization main water inlet regulating valve 20, closes the primary crystallization return water main valve 51, opens the primary crystallization auxiliary line cut-off valve 52, fully opens the primary crystallization water inlet regulating valve a22, primary crystallization water inlet regulating valve b23, primary crystallization water inlet regulating valve c24 and primary crystallization water inlet regulating valve d25, opens the primary crystallization compressed air inlet cut-off valve 36, and presses the sweating water in the primary crystallizer 108 into the sweating water tank 39. When the reading of the primary crystallizer compressed air flow meter 37 reaches 550Nm 3 / h, the system automatically closes the primary crystallizer compressed air inlet shut-off valve 36, the primary crystallizer auxiliary line shut-off valve 52, the primary crystallizer sweat water return shut-off valve 50, the primary crystallizer auxiliary line shut-off valve 52, the primary crystallizer water inlet regulating valve a22, the primary crystallizer water inlet regulating valve b23, the primary crystallizer water inlet regulating valve c24, and the primary crystallizer water inlet regulating valve d25. A sweat water tank on-site vent line 107 is installed at the top of the sweat water tank 39 to promptly discharge compressed air during water compression and prevent overpressure in the sweat water tank 39.

[0058] The crystallization process takes about an hour, so the volume of the boiling water tank 62 only needs to meet the volume required for the crystallization of one crystallizer. The system automatically detects the boiling water tank level gauge 59. When the liquid level reading is below 70%, the system automatically opens the process water inlet regulating valve b58 and begins to feed water into the boiling water tank 62. When the reading of the boiling water tank level gauge 59 reaches 70%, the process water inlet regulating valve b58 is closed and the boiling water pump 63 is started. The boiling water return regulating valve 65 is automatically linked to the boiling water pump outlet pressure gauge 64, and the pressure setting value is 0.5 MPa to ensure the continuous and normal operation of the boiling water pump 63. The boiling water tank thermometer 60 is automatically linked to the boiling water tank steam regulating valve 61, and the setting value is 40 degrees. If the temperature is below 40 degrees, steam heating is automatically applied. When the temperature reaches 40 degrees, the boiling water tank steam regulating valve 61 is closed. After the system detects that the reading on the boiling water tank level gauge 59 is greater than 65% and the reading on the boiling water tank thermometer 60 is greater than 35°C, it sequentially opens the primary crystallizer return water shutoff valve 67, the primary crystallizer return water main shutoff valve 51, and the primary crystallizer melting water inlet shutoff valve 66. The primary crystallizer main inlet regulating valve 20 is opened to 50%, and the valve positions of the primary crystallizer inlet regulating valves a22, b23, c24, and d25 are opened to 30%. This valve opening maintains a stable reading on the boiling water tank thermometer 60 between 35 and 40°C. Excessive opening can result in excessively low temperatures in the boiling water tank 62. When the readings on the primary crystallizer thermometers a26, b27, c28, and d29 in the primary crystallizer 108 all reach 30°C, the primary crystallizer melting process is complete.

[0059] Primary crystallization degraded water process: the system automatically closes the primary crystallizer dehydrated water inlet shut-off valve 66, the primary crystallization return water main valve 51 and the primary crystallization total water inlet regulating valve 20, opens the primary crystallization secondary line shut-off valve 52, fully opens the primary crystallization water inlet regulating valve a22, the primary crystallization water inlet regulating valve b23, the primary crystallization water inlet regulating valve c24 and the primary crystallization water inlet regulating valve d25, opens the primary crystallization compressed air inlet shut-off valve 36, pressurizes the dehydrated water in the primary crystallizer 108 to the dehydrated water tank 62; when the reading of the primary crystallizer compressed air inlet flowmeter 37 reaches 550Nm 3 / h, the system automatically closes the primary crystallizer compressed air inlet shut-off valve 36, the primary crystallizer auxiliary line shut-off valve 52, the primary crystallizer boiled water return shut-off valve 67, the primary crystallizer water inlet regulating valves a22, b23, c24, and d25. A boiled water tank vent line 68 is located at the top of the boiled water tank 62 to promptly discharge compressed air during water compression and prevent overpressure in the boiled water tank 62.

[0060] Primary crystallization degradation cutting process: The system automatically detects the reading of the secondary raw material tank weighing module 70. When it is less than 1t, the primary crystallization discharge shut-off valve 73 is opened, and the vinylene carbonate with a purity of 99.95% in the primary crystallizer 108 enters the secondary raw material tank 69; when the reading of the secondary raw material tank weighing module 70 is greater than 22t and remains stable for three minutes without changing, the primary crystallization discharge shut-off valve 73 is closed.

[0061] Secondary raw material circulation process: the system automatically opens the secondary crystallization circulation shut-off valve 76 and starts the secondary raw material circulation pump 74. The system automatically detects the pump operating current. During the startup current excessive stage, the secondary crystallizer feed regulating valve 75 is in a closed state. After the current stabilizes for 3 seconds, the secondary crystallizer feed regulating valve 75 gradually opens automatically to 35% opening; when the opening is reached, it is automatically linked to the secondary crystallizer air inlet flowmeter 77 display data, and the set value is 16t / h. The secondary crystallizer feed regulating valve 75 automatically stabilizes at about 16t / h according to the value displayed by the secondary crystallizer air inlet flowmeter 77.

[0062] Secondary crystallization process: The system detects normal chilled water operation. This detection condition includes normal operating signals and current readings from chilled water pump 7, and normal operation of the chilled water tank thermometer 10 and chilled water tank level gauge 12. At this point, the secondary crystallization command begins, sequentially opening the secondary crystallization chilled water return shut-off valve 81, secondary crystallization return shut-off valve 84, and secondary crystallization chilled water inlet shut-off valve 111. The system automatically opens the secondary crystallization main inlet regulating valve 94, automatically controlling the flow rate with the secondary crystallization inlet flowmeter 36. The flow rate is set to 30 t / h. At this point, the chilled water return regulating valve 19 is 100% open, and the 10-degree water return regulating valve 30 is closed to maintain a slow decrease in the chilled water tank level. Simultaneously, temperature control automatically operates to maintain the chilled water tank temperature. Based on multiple manual calibrations, the output valve position of secondary crystallization inlet regulating valve a 86 is 61%, the output valve position of secondary crystallization inlet regulating valve b 88 is 50%, the output valve position of secondary crystallization inlet regulating valve c 90 is 37%, and the output valve position of secondary crystallization inlet regulating valve d 92 is 23%. At this valve position, the vinylene carbonate crystallizes relatively quickly. At the end of crystallization, the temperatures of secondary crystallizer thermometers a 85, b 87, c 89, and d 91 within secondary crystallizer 109 are similar. Post-melt analysis shows very few crystalline impurities, demonstrating that the output valve position is optimally aligned with the process under these equipment operating conditions. As 10°C water enters the chilled water tank, the liquid level gradually rises. When the chilled water tank level gauge 12 reaches 70%, the 10°C water return regulating valve 30 opens. This valve is automatically linked to the 10°C water return flowmeter 32, and the chilled water tank inlet regulating valve 15 is automatically linked to the chilled water tank inlet flowmeter 31. The system now sets the chilled water tank inlet flowmeter 31 and the 10°C water return flowmeter 32 to an equivalent value, ensuring the liquid level in the chilled water tank 13 remains stable at 70%. Simultaneously, the chilled water tank inlet flowmeter 31 is automatically linked to the chilled water tank thermometer 10, ensuring the temperature in the chilled water tank 13 remains stable at 18°C. The chilled water return regulating valve 19 is automatically linked to the chilled water return flowmeter 35. The setpoint logic for the chilled water return regulating valve 19 defaults to 100% when the crystallizer is using chilled water. When the chilled water tank level gauge 12 reaches 70%, another set of control logic is triggered. The control method automatically detects the crystallization status of the primary and secondary crystallizers and confirms the switch status of the primary crystallizer's chilled water inlet shut-off valve 18 and the secondary crystallizer's chilled water inlet shut-off valve 111. If they are open, the circulation flow rate for one channel is 30 t / h, and for two channels it is 60 t / h. The chilled water return flowmeter 35 is automatically set to the total circulation flow required for crystallization minus the value displayed by the chilled water tank inlet flowmeter 31. This ensures stable control of the chilled water tank liquid level. During the secondary crystallization process, the vinylene carbonate in the secondary raw material tank 69 gradually decreases. When the secondary raw material tank weighing module 70 displays a value of 3 t, the secondary raw material crystallization is complete.Close the secondary crystallizer feed regulating valve 75. Three minutes later, close the secondary raw material tank circulation shut-off valve 76 and stop the secondary raw material circulation pump 74. Three tons of mother liquor remain in the secondary raw material tank. Each time the primary crystallization raw material tank pumps out excess mother liquor to the upstream distillation unit, start the secondary raw material pump 74, open the delivery shut-off valve 78, and deliver the mother liquor to the primary raw material tank 2 to be used as the feedstock for the next crystallization. Because the secondary crystallization cycle is shorter than the primary crystallization cycle, there is no conflict in system operation.

[0063] Secondary crystallization cooling chilled water process: The system automatically closes the secondary crystallization chilled water inlet shut-off valve 111, the secondary crystallization total water inlet regulating valve 94 and the secondary crystallization chilled water return shut-off valve 81, opens the secondary crystallization drain shut-off valve 93, fully opens the secondary crystallization water inlet regulating valve a 86, the secondary crystallization water inlet regulating valve b 88, the secondary crystallization water inlet regulating valve c 90 and the secondary crystallization water inlet regulating valve d 92, opens the secondary crystallizer compressed air inlet shut-off valve 80, pressurizes the chilled water in the secondary crystallizer 109 to the 10-degree water storage tank of the public works, and the secondary crystallizer compressed air inlet flowmeter 79 displays the inlet flow rate. The flow rate is 300Nm when the water is steadily pressurized. 3 When the water in the secondary crystallizer 109 is drained, the compressed air flow rate will instantly rise to 550Nm 3 / h, at this time the system automatically closes the secondary crystallizer compressed air inlet shut-off valve 80, the secondary crystallizer drain shut-off valve 93, the secondary crystallizer water inlet regulating valve a 86, the secondary crystallizer water inlet regulating valve b 88, the secondary crystallizer water inlet regulating valve c90 and the secondary crystallizer water inlet regulating valve d92.

[0064] Secondary crystallization sweating process: The secondary crystallization sweating time is about 10 hours. The system detects that the sweating water tank liquid level gauge 41 is greater than 30%, and the sweating water tank thermometer 44 is at 22±0.1 degrees. The secondary sweat tank feed cut-off valve 96, the secondary crystallization sweating return water cut-off valve 82, the secondary crystallization return water cut-off valve 84 and the secondary crystallization sweat inlet cut-off valve 98 are opened. The secondary crystallization total water inlet regulating valve 94 has a valve opening of 30%, the secondary crystallization water inlet regulating valve a 86 has a valve opening of 30%, the secondary crystallization water inlet regulating valve b 88 has a valve opening of 30%, the secondary crystallization water inlet regulating valve c 90 has a valve opening of 30%, the secondary crystallization water inlet regulating valve d 92 has a valve opening of 30%, and the secondary crystallization total water inlet regulating valve 94 is automatically associated with the secondary crystallization water inlet flowmeter 110, and the flow rate is set to 15t / h. Under this condition, the readings of the secondary crystallizer thermometer a 85, secondary crystallizer thermometer b 87, secondary crystallizer thermometer c 89 and secondary crystallizer thermometer d 91 in the secondary crystallizer 109 will gradually increase; when the reading of one of the thermometers reaches 21.6 degrees, the set value of the secondary crystallization water inlet flowmeter 110 is changed to 10t / h, the valve position of the secondary crystallization water inlet regulating valve a 86 is changed to 10%, the valve position of the secondary crystallization water inlet regulating valve b 88 is changed to 7%, the valve position of the secondary crystallization water inlet regulating valve c 90 is changed to 4%, and the valve position of the secondary crystallization water inlet regulating valve d 92 is changed to 1%. Under these conditions, impurities flow into the secondary sweat tank 71 along with the sweat. When the reading on the secondary sweat tank weighing module 72 reaches 2.5 tons, the system automatically issues an alarm. On-site personnel collect samples at sampling point 21 and send them to the laboratory for analysis. The analysis indicates that the ethylene carbonate content is less than 99.995%. Based on the analysis results, the sweating time is determined to continue until the sample analysis indicates that the ethylene carbonate content is greater than 99.995%, marking the end of the sweating process. The purpose of sample testing is to ensure product quality. The operator in the DCS automatically closes the secondary sweat tank feed shut-off valve 96 by clicking the secondary melt start button on the operation screen. Before the next feed to the primary raw material tank 2, the reading on the secondary sweat tank weighing module 72 is checked. Once the presence of sweat is confirmed, the secondary sweat pump 101 is activated, and the primary sweat pump outlet shut-off valve 100 is opened to pump sweat into the primary raw material tank 2. When the reading on the secondary sweat tank weighing module 72 reaches 0, the secondary sweat pump outlet shut-off valve 100 is closed, the secondary sweat pump 101 is stopped, and the secondary sweat is used as raw material for the next crystallization.

[0065] Secondary crystallization sweat water removal process: the system automatically closes the secondary crystallization sweat water inlet cut-off valve 98, closes the secondary crystallization total water inlet regulating valve 94, closes the secondary crystallization return water cut-off valve 84, opens the secondary crystallization secondary line cut-off valve 99, fully opens the secondary crystallization water inlet regulating valve a 86, the secondary crystallization water inlet regulating valve b 88, the secondary crystallization water inlet regulating valve c 90 and the secondary crystallization water inlet regulating valve d 92, opens the secondary crystallizer compressed air inlet cut-off valve 80, and presses the sweat water in the secondary crystallizer 109 to the sweat water tank 39; when the secondary crystallizer compressed air inlet flow meter 79 shows 550Nm 3 / h, the system automatically closes the secondary crystallizer compressed air inlet shut-off valve 80, the secondary crystallization auxiliary line shut-off valve 99, the secondary crystallization sweat water return shut-off valve 82, the secondary crystallization water inlet regulating valve a 86, the secondary crystallization water inlet regulating valve b 88, the secondary crystallization water inlet regulating valve c 90 and the secondary crystallization water inlet regulating valve d 92.

[0066] Secondary crystallization process: The secondary crystallization time is about 0.7 hours. After the system detects that the reading of the boiling water tank level gauge 59 is greater than 65% and the reading of the boiling water tank thermometer 60 is greater than 35 degrees, the system opens the secondary crystallization return water cut-off valve 83, the secondary crystallization return water cut-off valve 84 and the secondary crystallizer boiling water cut-off valve 97 in sequence, and the secondary crystallization total water inlet regulating valve 94 is opened to 50%. The valve positions of the secondary crystallization water inlet regulating valve a 86, the secondary crystallization water inlet regulating valve b 88, the secondary crystallization water inlet regulating valve c 90 and the secondary crystallization water inlet regulating valve d92 are opened to 30%. This regulating valve position opening can maintain the reading of the boiling water tank thermometer 44 stable at 35-40 degrees. Excessive opening will cause the boiling water tank temperature to be too low. When the readings of the secondary crystallizer thermometers a 85, b 87, c 89 and d 91 in the secondary crystallizer 109 all reach 30 degrees, the secondary crystallization process is completed.

[0067] Secondary crystallization degraded boiling water process: the system automatically closes the secondary crystallizer degraded boiling water cut-off valve 97, the secondary crystallization return water cut-off valve 84 and the secondary crystallization total boiling water regulating valve 94, opens the secondary crystallization secondary line cut-off valve 99, fully opens the secondary crystallization boiling water regulating valve a86, the secondary crystallization boiling water regulating valve b88, the secondary crystallization boiling water regulating valve c90 and the secondary crystallization boiling water regulating valve d92, opens the secondary crystallization compressed air intake cut-off valve 80, and pressurizes the boiling water in the secondary crystallizer 109 to the boiling water tank 62; when the secondary crystallizer compressed air intake flow meter 79 shows 550Nm 3 / h, the system automatically closes the secondary crystallizer compressed air inlet shut-off valve 80, the secondary crystallization auxiliary line shut-off valve 99, the secondary crystallization return water shut-off valve 83, the secondary crystallization water inlet regulating valve a86, the secondary crystallization water inlet regulating valve b 88, the secondary crystallization water inlet regulating valve c 90 and the secondary crystallization water inlet regulating valve d92.

[0068] Secondary Crystallization Degradation Cutting Process: When the system automatically detects that the reading on the melting tank weighing module 103 is less than 30 tons, the secondary crystallization discharge shut-off valve 95 opens, allowing the 99.999% pure vinylene carbonate in the secondary crystallizer 109 to enter the melting tank 102. After the reading on the melting tank weighing module 103 remains stable for three minutes, the secondary crystallization discharge shut-off valve 95 closes. If the reading on the melting tank weighing module 103 exceeds 30 tons, the system suspends material withdrawal and issues an alarm. The workshop operator promptly activates the melting pump 104 according to the packaging process schedule, pumping the vinylene carbonate in the melting tank downstream to maintain continuous system operation.

[0069] Crystallization heating process: When the reading of the liquid level gauge 59 of the melt tank is greater than 20%, the heating circulation pump 106 can be enabled to provide heating to the equipment pipeline 105 of the workshop crystallization unit.

[0070] The utility model collects data based on the manual operation of the operator, and then controls the entire crystallization process through the instrument automation program, which greatly reduces the requirements for the operator's operating proficiency, makes the process node control more precise, avoids misoperation, and at the same time, the efficiency and yield of the output product are higher. By optimizing the shell structure of the crystallizer, the purpose of improving yield and efficiency can also be achieved. Through the secondment control of the chilled water tank and the public engineering 10-degree water storage tank, and the use of the boiling water tank water source for the equipment and pipeline heating water of the crystallization unit, the actual needs of the process are met, the equipment construction cost is greatly reduced, and the workshop space is saved.

[0071] The jackets of the primary and secondary crystallizers of this utility model are replaced with segmented jackets, which evenly distribute the jackets on the entire device, reducing and concentrating the internal circulating medium. This allows for faster heating or cooling, reduces heating or cooling time, and increases heat transfer or cooling efficiency. A temperature sensor and an automatic regulating valve are added to the inlet and outlet of each section of the barrel jacket. The value displayed by the temperature sensor is linked to the opening of the automatic regulating valve to control the temperature within the specified value range, ensuring temperature stability more accurately and enabling the material to be purified in one go, thereby increasing production capacity, reducing material consumption, and saving costs.

[0072] The above description is only an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the scope of protection of the present invention.

Claims

1. A fully automatic control system for vinylene carbonate crystallization process, characterized in that: include: Primary crystallization module, used for primary crystallization, primary sweating and primary melting of vinylene carbonate semi-finished products; The secondary crystallization module is connected to the primary crystallization module, and is used to perform secondary crystallization, secondary sweating and secondary melting processes on the vinylene carbonate solution output from the primary crystallization module; The temperature control module is connected to the primary crystallization module and the secondary crystallization module, and provides temperature-controlled water for each process for the primary crystallization module and the secondary crystallization module respectively.

2. The fully automatic control system for vinylene carbonate crystallization process according to claim 1, characterized in that: The primary crystallization module comprises a primary raw material tank (2), a primary sweat tank (54) and a primary crystallizer (108), wherein the shell of the primary crystallizer (108) is a primary crystallization sandwich temperature control structure, and the primary crystallization sandwich temperature control structure is connected to the temperature control module; The bottom of the primary crystallizer (108) is connected to the primary raw material tank (2), the primary sweat tank (54) and the secondary crystallization module respectively through three branch pipelines, and each branch pipeline is provided with a control valve; the primary sweat tank (54) is connected to the primary raw material feed port of the primary raw material tank (2) through a primary sweat pump (56) and a pipeline, and the primary raw material feed port is also connected to the vinylene carbonate semi-finished product feed line. The primary raw material tank (2) is connected to the top of the primary crystallizer (108) and the upstream distillation unit through a primary raw material circulation pump (4) and a primary crystallization circulation pipeline, and each pipeline is provided with a control valve.

3. The fully automatic control system for vinylene carbonate crystallization process according to claim 2, characterized in that: The secondary crystallization module comprises a secondary raw material tank (69), a secondary sweat tank (71), a melting tank (102) and a secondary crystallizer (109), wherein the shell of the secondary crystallizer (109) is a secondary crystallization sandwich temperature control structure, and the secondary crystallization sandwich temperature control structure is connected to the temperature control module; The bottom of the secondary crystallizer (109) is connected to the secondary raw material tank (69), the secondary sweat tank (71) and the melting tank (102) through three branch pipelines, and each branch pipeline is provided with a control valve; the secondary raw material tank (69) is connected to the top of the secondary crystallizer (109) through a secondary raw material circulation pump (74) and a secondary raw material circulation pipeline, the secondary sweat tank (71) is connected to the primary raw material tank (2) through a secondary sweat pump (101) and a pipeline, and the melting tank (102) is connected to the finished product line through a melting pump (104).

4. The fully automatic control system for vinylene carbonate crystallization process according to claim 3, characterized in that: The primary crystallization interlayer temperature control structure of the primary crystallizer (108) is the same as the secondary crystallization interlayer temperature control structure of the secondary crystallizer (109), both of which include multiple sections of jackets with independent cavities arranged in sequence along the height direction, and the inlet and outlet of each section of the jacket are respectively provided with a temperature sensor and an automatic regulating valve, and the value displayed by the temperature sensor is linked to the opening of the automatic regulating valve for control.

5. The fully automatic control system for vinylene carbonate crystallization process according to claim 3, characterized in that: The primary raw material tank (2) is provided with a raw material tank weighing module (3) for weighing the raw material; and the secondary raw material tank (69) is provided with a secondary raw material tank weighing module (70) for weighing the secondary raw material.

6. The fully automatic control system for vinylene carbonate crystallization process according to claim 3, characterized in that: The temperature control module includes a chilled water control module, a sweating water control module and a boiling water control module; The primary crystallizer (108) is connected to the chilled water control module, the sweating water control module and the boiling water control module to form a primary chilled water circulation system, a primary sweating water circulation system and a primary boiling water circulation system; The secondary crystallizer (109) is connected to the chilled water control module, the sweating water control module and the boiling water control module to form a secondary chilled water circulation system, a secondary sweating water circulation system and a secondary boiling water circulation system; The return pipelines of the primary crystallizer (108) and the secondary crystallizer (109) are connected to the compressed air pipeline, and the chilled water, sweating water and boiled water are pressed back by compressed air.

7. The fully automatic control system for vinylene carbonate crystallization process according to claim 6, characterized in that: The chilled water control module includes a chilled water tank (13) and a chilled water pump (7), wherein the water inlet of the chilled water pump (7) is connected to the bottom of the chilled water tank (13), and the water outlet of the chilled water pump (7) is connected to the top of the chilled water tank (13), the primary crystallizer (108), the secondary crystallizer (109) and the return water main through multiple branch pipelines, and each branch pipeline is provided with a control valve; the primary crystallizer (108) and the secondary crystallizer (109) are connected to the top of the chilled water tank (13) through a chilled water return pipeline; and the top of the chilled water tank (13) is connected to a 10°C water inlet pipeline.

8. The fully automatic control system for vinylene carbonate crystallization process according to claim 6, characterized in that: The sweating water control module includes a sweating water tank (39) and a sweating water pump (45), wherein the water inlet of the sweating water pump (45) is connected to the bottom of the sweating water tank (39) through a pipeline, and the water outlet of the sweating water pump (45) is connected to the top of the sweating water tank (39), the primary crystallizer (108) and the secondary crystallizer (109) through multiple branch pipelines, and each branch pipeline is provided with a control valve; the primary crystallizer (108) and the secondary crystallizer (109) are connected to the top of the sweating water tank (39) through a sweating water return pipeline; and the top of the sweating water tank (39) is connected to the process water inlet pipeline.

9. The fully automatic control system for vinylene carbonate crystallization process according to claim 6, characterized in that: The boiling water control module comprises a boiling water tank (62) and a boiling water pump (63), wherein the water inlet of the boiling water pump (63) is connected to the bottom of the boiling water tank (62), and the water outlet of the boiling water pump (63) is connected to the top of the boiling water tank (62), the primary crystallizer (108) and the secondary crystallizer (109) through multiple branch pipelines, and each branch pipeline is provided with a control valve; the primary crystallizer (108) and the secondary crystallizer (109) are connected to the top of the boiling water tank (62) through a boiling water return pipeline; and the top of the boiling water tank (62) is connected to a process water inlet pipeline.

10. The fully automatic control system for vinylene carbonate crystallization process according to claim 6, characterized in that: The temperature of the frozen water is 17-18°C, the temperature of the sweating water is 20-22°C, and the temperature of the boiled water is 35-40°C.

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