A production system of methomyl

Abstract

This application discloses a methomyl production system. A filter cylinder is connected to the bottom of the methomyl reactor via a jacketed feed pipe and a methomyl concentrate pump. In operation, raw materials are added to the methomyl reactor and kept at a constant temperature for reaction. The resulting solution is then pumped through the jacketed feed pipe to the filter cylinder for filtration to remove excess activated carbon. The filtered solution is then transferred through the jacketed pipe to a methomyl crystallization reactor for crystallization at 2-60°C. The crystallized material is then fed into a filter press to remove moisture. Wastewater is discharged into a wastewater tank, and the material is dried in a dryer. When the liquid level in the filter cylinder reaches the high level, it is returned to the methomyl reactor through the jacketed reflux pipe. The use of hot water prevents crystallization of the synthesized compound in the filter cylinder, jacketed feed pipe, jacketed pipe, and jacketed reflux pipe. This production system can filter out activated carbon mixed in the synthesized material in the reactor, thereby improving the purity and quality of the finished methomyl product and ensuring its insecticidal effect.

Description

Technical Field

[0001] This utility model relates to the field of methomyl production and preparation technology, and in particular to a methomyl production system. Background Technology

[0002] Methomyl is a carbamate insecticide with broad-spectrum and high efficacy. It is a white crystalline solid that primarily controls various pests on crops, such as aphids, planthoppers, and stem borers, through contact and stomach poison action. It is suitable for fruit trees, vegetables, and cotton, and can be mixed with some pesticides but not with alkaline pesticides. It is stable at room temperature but decomposes easily in moist soil and poses a toxic risk to fish.

[0003] This substance undergoes an exothermic reaction with methylthioacetaldehyde oxime (methomyl oxime) and methyl isocyanate in the presence of a solvent (water). After crystallization, pressure filtration, and drying, methomyl technical is obtained. Traditionally, refined methomyl oxime is used as the raw material. However, refined methomyl oxime is expensive. Therefore, in order to reduce production costs, crude methomyl oxime is currently used as the raw material to produce methomyl technical. However, the existing production system cannot filter out the activated carbon mixed in the reaction vessel, which affects the purity and quality of the finished methomyl product, and thus affects the insecticidal effect. Utility Model Content

[0004] The purpose of this application is to provide a methomyl production system to solve the problem that in the current methomyl preparation process, it is impossible to filter out the activated carbon mixed in the synthesis material in the reactor, which affects the purity and quality of the finished methomyl product and thus affects the insecticidal effect.

[0005] To solve the above-mentioned technical problems, this application provides a methomyl production system, comprising:

[0006] The methomyl reaction vessel has a filter cylinder connected to its bottom outlet via a jacketed feed pipe and a methomyl concentrate pump. The bottom outlet of the filter cylinder is connected to a methomyl crystallizing vessel via a jacketed pipe. The lower outlet of the methomyl crystallizing vessel is connected to a filter press via a discharge pipe. One end of the filter press's wastewater discharge pipe is connected to a wastewater tank, and the other end of the filter press's discharge pipe is connected to a dryer.

[0007] The jacketed feed pipe is connected to a jacketed return pipe near the filter cylinder, and one end of the jacketed return pipe is connected to the feed inlet of the methomyl reactor.

[0008] The hot water in the hot water tank is fed into the jacketed feed pipe, the filter cylinder, the jacketed pipe, and the jacketed return pipe via a drying hot water pump. The water that has undergone heat exchange in the jacketed feed pipe, the filter cylinder, the jacketed pipe, and the jacketed return pipe flows back to the hot water tank via a return water pipe.

[0009] In a preferred embodiment, a methomyl production system is provided in which a porous plate is provided inside the filter cylinder through a support ring and a support tube, and the filter cloth is fixed on the porous plate.

[0010] The solution requires detailed explanation of a methomyl production system, wherein a filtrate sight glass is also installed on the discharge pipe.

[0011] In a preferred embodiment, a methomyl production system is provided, wherein a reflux jacket pipe is connected between the discharge pipe and the inlet of the methomyl concentrate pump, and hot water in the hot water tank is also connected to the reflux jacket pipe.

[0012] In a preferred embodiment, a methomyl production system is provided with an exhaust pipe at the top of the filter cylinder.

[0013] Compared with the prior art, the methomyl production system provided by this utility model includes a methomyl reaction vessel. A filter cylinder is connected to the bottom outlet of the methomyl reaction vessel via a jacketed feed pipe and a methomyl concentrate pump. In use, raw materials are added to the methomyl reaction vessel and kept at a constant temperature for reaction. The resulting solution is then pumped through the jacketed feed pipe to the filter cylinder via the methomyl concentrate pump for filtration to remove excess activated carbon. The bottom outlet of the filter cylinder is connected to a methomyl crystallization vessel via a jacketed pipe. The filtered solution is then transferred through the jacketed pipe to the methomyl crystallization vessel for crystallization at 2-60℃. For crystallization, a filter press is connected to the lower outlet of the methomyl crystallizer via a discharge pipe. One end of the filter press's wastewater discharge pipe is connected to a wastewater tank, and the other end of the filter press's discharge pipe is connected to a dryer. The crystallized material enters the filter press to remove moisture, the wastewater enters the wastewater tank, and the material enters the dryer for drying. A jacketed reflux pipe is connected to the jacketed feed pipe near the filter cylinder. One end of the jacketed reflux pipe is connected to the inlet of the methomyl reactor. In actual production, when the liquid level in the filter cylinder reaches the high-level interlock value, it flows back to the methomyl reactor through the jacketed reflux pipe. In this system, hot water from the hot water tank is pumped through a drying hot water pump into the jacketed feed pipe, filter cylinder, jacketed pipe, and jacketed return pipe. Water that has undergone heat exchange in these components returns to the hot water tank via a return water pipe. The purpose of using hot water is to prevent crystallization of the synthesized compound within the filter cylinder, jacketed feed pipe, jacketed pipe, and jacketed return pipe. This production system can filter out activated carbon mixed in with the synthesized material in the reactor, thereby improving the purity and quality of the final methomyl product and ensuring its insecticidal effect. Attached Figure Description

[0014] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0015] Figure 1 This is a schematic diagram of a methomyl production system provided in an embodiment of this application;

[0016] Figure 2 This is a schematic diagram of a filter cylinder structure provided in an embodiment of this application;

[0017] In the diagram: 1. Methomyl reaction vessel; 2. Jacketed feed pipe; 3. Methomyl crystallization vessel; 30. Reflux jacketed pipe; 4. Methomyl concentrate pump; 5. Filter cylinder; 6. Jacketed pipe; 7. Discharge pipe; 8. Filter press; 9. Wastewater tank; 10. Dryer; 11. Jacketed reflux pipe; 12. Hot water tank; 13. Drying hot water pump; 14. Return water pipe; 15. Filtration sight glass; 16. Support ring; 17. Support pipe; 18. Perforated plate; 19. Tail gas emission pipe. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0019] The core of this application is to provide a methomyl production system that solves the problem that, in the current methomyl preparation process, it is impossible to filter out the activated carbon mixed in the synthesis material in the reactor, which affects the purity and quality of the finished methomyl product and thus the insecticidal effect.

[0020] Figure 1 This is a schematic diagram of a methomyl production system provided in an embodiment of this application. Figure 2 This is a schematic diagram of a filter cylinder structure provided in an embodiment of this application. Figure 1 The blue arrows indicate the direction of water flow, and the black arrows indicate the direction of material movement. See also... Figures 1 to 2 As shown.

[0021] Example 1

[0022] A methomyl production system includes a methomyl reaction vessel 1. A filter cylinder 5 is connected to the bottom outlet of the methomyl reaction vessel 1 via a jacketed feed pipe 2 and a methomyl concentrate pump 4. The bottom outlet of the filter cylinder 5 is connected to a methomyl crystallizing vessel 3 via a jacketed pipe 6. A filter press 8 is connected to the lower outlet of the methomyl crystallizing vessel 3 via a discharge pipe 7. One end of the wastewater discharge pipe of the filter press 8 is connected to a wastewater tank 9, and one end of the discharge pipe of the filter press 8 is connected to a dryer 10. The filter press 8 can be a Newker filter press.

[0023] A jacketed reflux pipe 11 is connected to the jacketed feed pipe 2 near the suction filter cylinder 5. One end of the jacketed reflux pipe 11 is connected to the feed inlet of the methomyl reactor 1.

[0024] The hot water in the hot water tank 12 is fed into the jacketed conveying pipe 2, the suction filter cylinder 5, the jacketed pipe 6 and the jacketed return pipe 11 through the drying hot water pump 13. The water that has undergone heat exchange in the jacketed conveying pipe 2, the suction filter cylinder 5, the jacketed pipe 6 and the jacketed return pipe 11 is returned to the hot water tank 12 through the return water pipe 14.

[0025] In the actual production process, the methyl isocyanate (hereinafter referred to as isocyanate) metering tank is first used for material preparation. Then, it is checked that there is no material in the methomyl reactor 1 and the discharge valve is closed. The valves on the isocyanate dripping pipeline, the steam inlet pipeline, and the methylthioacetaldehyde oxime inlet pipeline are closed, while the valves on the venting and reflux pipelines are open. The stirring of the methomyl reactor 1 is started, the manual valve on the water inlet pipeline of the methomyl reactor 1 is opened, and the deionized water pump is started for feeding. When the cumulative flow reaches the set value, the water inlet valve of the deionized water pipeline is interlocked and closed. After it is checked and confirmed that the water feeding of the methomyl reactor 1 is complete, the stirring of the methomyl reactor 1 is checked and confirmed that the valves on the isocyanate dripping pipeline, the steam inlet pipeline, and the solvent or recovered mother liquor inlet pipeline are closed, while the valves on the venting and reflux pipelines are open. The feed valve of the methomyl reactor 1 is opened, and 5 kg of activated carbon is manually broken and put into the solid feed port.

[0026] Next, feed the methylthioacetaldehyde oxime. After accurately counting 50 bags of methylthioacetaldehyde oxime raw material in advance, place them near the solid feed port. Manually break open the bags of methylthioacetaldehyde oxime (25kg / bag) and put them into the solid feed port. After putting in 50 bags, close the methylthioacetaldehyde oxime feed valve.

[0027] Next, the isoester was added dropwise.

[0028] Open the manual valve on the ice-salt water outlet pipeline of the methomyl reactor 1 jacket; open the ice-salt water inlet valve of the methomyl reactor 1 jacket and confirm that the temperature and pressure on the ice-salt water inlet pipeline meet the requirements; check and confirm that the agitator of the methomyl reactor 1 is turned on; check and confirm that the valves on the steam inlet pipeline, the solvent or mother liquor recovery pipeline, and the methylthioacetaldehyde oxime inlet pipeline are closed, and the valves on the venting and reflux pipelines are open; open the bottom valve of the isoester metering tank and the manual valve on the isoester dripping pipeline, and check and confirm that the emergency discharge valve is closed; when the temperature of the methomyl reactor 1 is between 4-25℃, open the isoester feed valve on the dripping pipeline, and set the maximum opening of the regulating valve to a maximum of 250L / h. Do not drip when the temperature is below 4℃; when the cumulative flow reaches the set value, interlock and close the isoester feed valve.

[0029] The reaction should be kept at a constant temperature for 30 minutes, and the temperature of the methomyl reactor should be controlled at 58-63℃.

[0030] Close the inlet valve of the ice-salt water in the jacket of the methomyl reactor 1 and maintain the temperature for 30 minutes; open the manual valve on the steam inlet pipeline of the methomyl reactor 1 and open the steam switch valve; when the material in the methomyl reactor 1 reaches the set temperature, the thermometer interlock closes the steam switch valve.

[0031] Next, the material is transferred.

[0032] Confirm that the outlet valve of methomyl concentrate pump 4 is closed; confirm that the feed valve KV07466 of filter cylinder 5, the return valve of methomyl concentrate pump 4, the inlet valve of methomyl concentrate pump 4, and the tail gas butterfly valve of filter cylinder 5 are open; confirm that the hot water supply and return water of filter cylinder 5 are in use, and that the hot water in jacketed conveyor pipe 2, jacketed pipe 6, and jacketed return pipe 11 are in use; open the manual valve of the ice-salt water outlet pipeline of the jacket of methomyl crystallizer 3; open the ice-salt water inlet valve of the jacket of methomyl crystallizer 3, and confirm the temperature and pressure on the ice-salt water inlet pipeline. Meets the requirements; open the bottom discharge valve KV07465 of the methomyl reactor 1 and start the agitator in the methomyl crystallizer 3; wait until the methomyl solution fills the methomyl concentrate pump 4, start the methomyl concentrate pump 4, slowly open the outlet valve of the methomyl concentrate pump 4, and pump the methomyl solution into the suction filter 5. Adjust the valve opening of the jacketed return pipe 11 of the methomyl reactor 1 according to the production control settings; start the methomyl discharge vacuum pump and observe whether the filtrate is being transported normally through the sight glass in the monitoring system; if the material is dark or black (indicating leakage), it indicates a leak. (Activated carbon), handled as an abnormal condition; when the liquid level in filter cylinder 5 reaches the high liquid level interlock value, the feed valve KV07466 of filter cylinder 5 is automatically closed by interlock, and at this time, the methomyl concentrate pump 4 is fully refluxed; when the liquid level in filter cylinder 5 reaches the low liquid level interlock value, the feed valve KV07466 of filter cylinder 5 is automatically opened by interlock; the central control observes the liquid level gauge of methomyl reactor 1, and when the liquid level reaches the low limit, the central control notifies the site to stop the methomyl concentrate pump 4, close the feed valve KV07466 of filter cylinder 5, and shut off the methomyl... Stop the methomyl discharge vacuum pump at the bottom valve KV07465 of reactor 1; after the synthesis of this batch is completed, add 2600L of deionized water into methomyl reactor 1, and confirm that the bottom valve KV07465 of methomyl reactor 1, the inlet valve of methomyl concentrate pump 4, and the reflux valve are open, while the outlet valve of methomyl concentrate pump 4 and the feed valve KV07466 of the filter cartridge 5 are closed. Start methomyl concentrate pump 4, and slowly open the outlet valve of methomyl concentrate pump 4 to clean the corresponding pipelines. The cleaning solution is eventually returned to methomyl reactor 1.

[0033] crystallization

[0034] The material inside the methomyl crystallizer 3 is cooled and crystallized, and the crystallization temperature is controlled between 2-60℃. After crystallization is completed, the jacket ice-salt water inlet valve is closed.

[0035] Filtration

[0036] Check and confirm that there is no material in filter press 8 and that the filter cloth is intact. Perform a pressure test and leak test on filter press 8 using nitrogen. After the leak test is passed, release the nitrogen and keep the vent valve open. Check and confirm that the solid discharge port of filter press 8 is closed, and that the filtrate valve and the valve on the filtrate discharge pipeline of filter press 8 are open. Open the bottom valve of methomyl crystallizer 3, open the feed valve of filter press 8, and put the material from the reactor into filter press 8. After there is no material in methomyl crystallizer 3, close the methomyl valve. Stirring and bottom valve of crystallizer 3; rely on gravity to filter until no filtrate flows out of filtrate sight glass 15 (about 20-60 minutes) and a filter cake layer is formed. Then close the vent valve of filter press 8, open the nitrogen switch valve on filter press 8, control the pressure ≤0.3MPa, and when the pressure of filter press 8 drops to 0.1MPa, close the nitrogen switch valve. After the pressure reaches normal pressure, open the nitrogen switch valve again and purge until there is no backflow in filtrate sight glass 15 (about 60 minutes). Then close the nitrogen switch valve.

[0037] Example 2

[0038] Based on Example 1, a methomyl production system includes a perforated plate 18 installed inside the filter cylinder 5 via a support ring 16 and a support pipe 17, with the filter cloth fixed to the perforated plate 18. Also based on Example 1, the methomyl production system includes a filtrate sight glass 15 installed on the discharge pipe 7. The filtrate sight glass 15 is used to observe whether the material in the discharge pipe 7 is normal. If the material is dark or black, it indicates a leak of activated carbon, requiring handling as an abnormal condition.

[0039] In this embodiment, a methomyl production system is provided, wherein a reflux jacket pipe 30 is connected between the discharge pipe 7 and the inlet of the methomyl concentrate pump 4, and the hot water in the hot water tank 12 is also connected to the reflux jacket pipe 30.

[0040] Abnormal operating condition handling methods: If the material is observed to be dark or black, the following actions are required:

[0041] (1) Take out the filter cloth inside the filter cylinder 5, connect deionized water to the filter cylinder 5, and rinse the filter cylinder 5 and the discharge pipe 7 with deionized water.

[0042] (2) After rinsing, confirm that the hand valve from methomyl crystallizer 3 to methomyl concentrate pump 4 and the feed valve of filter press 8 are closed. Open the bottom valve of methomyl crystallizer 3 and use a temporary steam hose to connect steam to heat the material in methomyl crystallizer 3. Observe the temperature of methomyl crystallizer 3. The temperature should not exceed 55℃.

[0043] (3) After the material in the methomyl crystallizer 3 is heated, close the steam valve and open the reflux hand valve from the methomyl crystallizer 3 to the methomyl concentrate pump 4. Confirm that the reflux hand valve of the methomyl concentrate pump 4 is open, close the feed valve of the filter cylinder 5 and the bottom valve of the methomyl reactor 1, and pump the material back to the methomyl reactor 1 through the reflux jacket pipe 30 via the methomyl concentrate pump 4. Replace the filter cloth and perform filtration again.

[0044] If the filtration speed of the filtration cartridge 5 is slow during use, the filter cloth needs to be replaced. The frequency of filter cloth replacement should be determined based on the filtration speed.

[0045] Based on Example 1, a methomyl production system further includes a tail gas discharge pipe 19 at the top of the filter cylinder 5 to discharge the generated tail gas.

[0046] This utility model provides a methomyl production system, including a methomyl reaction vessel 1. A filter cylinder 5 is connected to the bottom outlet of the methomyl reaction vessel 1 via a jacketed feed pipe 2 and a methomyl concentrate pump 4. In use, raw materials are added to the methomyl reaction vessel 1 and kept at a constant temperature for reaction. The resulting solution is then pumped through the jacketed feed pipe 2 to the filter cylinder 5 via the methomyl concentrate pump 4 for filtration to remove excess activated carbon. The bottom outlet of the filter cylinder 5 is connected to a methomyl crystallization vessel 3 via a jacketed pipe 6. The filtered solution is then transferred through the jacketed pipe 6 to the methomyl crystallization vessel 3 for crystallization at 2-60℃. A filter press 8 is connected to the lower outlet of the crystallizing vessel 3 via a discharge pipe 7. One end of the wastewater discharge pipe of the filter press 8 is connected to a wastewater tank 9, and the other end of the discharge pipe of the filter press 8 is connected to a dryer 10. The crystallized material enters the filter press 8 to remove moisture, the wastewater enters the wastewater tank 9, and the material enters the dryer 10 for drying. A jacketed feed pipe 2 is connected to a jacketed return pipe 11 near the suction filter cylinder 5. One end of the jacketed return pipe 11 is connected to the inlet of the methomyl reactor 1. In actual production, when the liquid level in the suction filter cylinder 5 reaches the high liquid level interlock value, it flows back to the methomyl reactor 1 through the jacketed return pipe 11. In this system, hot water from the hot water tank 12 is pumped by a drying hot water pump 13 into the jacketed feed pipe 2, the filter cylinder 5, the jacketed pipe 6, and the jacketed return pipe 11. The water that has undergone heat exchange in these components flows back to the hot water tank 12 via the return water pipe 14. The purpose of using hot water is to prevent the synthesized compound from crystallizing in the filter cylinder 5, the jacketed feed pipe 2, the jacketed pipe 6, and the jacketed return pipe 11. This production system allows for the filtration of activated carbon mixed in the synthesized material in the reactor, thereby improving the purity and quality of the methomyl product and ensuring its insecticidal effect.

[0047] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and incorporate common knowledge or customary techniques in the art disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of this application is indicated by the claims.

[0048] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The embodiments of this application described above do not constitute a limitation on the scope of protection of this application.

Claims

1. A methomyl production system, characterized in that, include: Methomyl reaction vessel (1), the bottom outlet of the methomyl reaction vessel (1) is connected to a filter cylinder (5) through a jacketed conveying pipe (2) and a methomyl concentrate pump (4), the bottom outlet of the filter cylinder (5) is connected to a methomyl crystallizer (3) through a jacketed pipe (6), the lower outlet of the methomyl crystallizer (3) is connected to a filter press (8) through a discharge pipe (7), one end of the wastewater discharge pipe of the filter press (8) is connected to a wastewater tank (9), and one end of the discharge pipe of the filter press (8) is connected to a dryer (10); The jacketed feed pipe (2) is connected to a jacketed return pipe (11) near the filter cylinder (5), and one end of the jacketed return pipe (11) is connected to the feed inlet of the methomyl reactor (1). The hot water in the hot water tank (12) is connected to the jacketed feed pipe (2), the filter cylinder (5), the jacketed pipe (6) and the jacketed return pipe (11) through the drying hot water pump (13). The water that has been heated in the jacketed feed pipe (2), the filter cylinder (5), the jacketed pipe (6) and the jacketed return pipe (11) is returned to the hot water tank (12) through the return water pipe (14).

2. The methomyl production system according to claim 1, characterized in that, The filter cylinder (5) is provided with a porous plate (18) through a support ring (16) and a support tube (17), and the filter cloth is fixed on the porous plate (18).

3. The methomyl production system according to claim 2, characterized in that, The discharge pipe (7) is also equipped with a filtrate sight glass (15).

4. The methomyl production system according to claim 3, characterized in that, A reflux jacket pipe (30) is also connected between the discharge pipe (7) and the inlet of the methomyl concentrate pump (4), and the hot water in the hot water tank (12) is also connected to the reflux jacket pipe (30).

5. The methomyl production system according to claim 1, characterized in that, The top of the filter cylinder (5) is also provided with an exhaust pipe (19).

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