Method and device for kettle-type continuous synthesis of dimethyl sulfoxide
The continuous synthesis of dimethyl sulfoxide in the No. 1 and No. 2 reactors is solved by kettle-type reactors, and the problems of slow reaction speed and high cost in the prior art are achieved, and efficient and low-cost dimethyl sulfoxide production is achieved.
Patent Information
- Application Number
- CN202510519553.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-24
- Publication Date
- 2025-07-25
AI Technical Summary
In the prior art, the continuous production of dimethyl sulfoxide uses a tube reactor or a plate reactor, which has the problem of slow reaction speed and high process cost.
The continuous synthesis of dimethyl sulfoxide was carried out using a kettle reactor. By conducting preliminary and further reactions in the No. 1 and No. 2 reactors, the maximum liquid volume limit was controlled, and combined with stirring and temperature control, high content and high yield production was achieved.
It improves synthesis efficiency, reduces process implementation costs, reduces side reactions and pollution emissions, and is suitable for industrial production.
Smart Images
Figure CN120365196A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of dimethyl sulfoxide preparation, and particularly relates to a method and a device for continuously synthesizing dimethyl sulfoxide in a kettle. Background Art
[0002] Dimethyl sulfoxide (DMSO) is a sulfur-containing compound with the molecular formula (CH3)2SO. It is a colorless, odorless transparent liquid under normal temperature conditions, with a melting point of 18.5 °C, a boiling point of 189 °C, a slightly bitter taste, and is easily soluble in water, alcohol, ether, and ester, and has strong hygroscopicity. Dimethyl sulfoxide belongs to an aprotic polar solvent. Due to its special solvent effect on chemical reactions and its solubility characteristics for many substances, it is called the "universal solvent"; currently, it has a wide range of applications in many chemical fields such as petroleum, chemical industry, medicine, electronics, synthetic fibers, plastics, and printing and dyeing.
[0003] In order to achieve the continuous production of dimethyl sulfoxide, many technologies have been proposed to use tubular reactors or tray reaction towers to replace the traditional reaction kettles for batch synthesis as the synthesis device for dimethyl sulfoxide, but there are problems such as slow reaction speed and high process costs.
[0004] Therefore, the applicant hopes to seek technical solutions to solve the above technical problems. Summary of the Invention
[0005] In view of this, the purpose of the present invention is to provide a method and a device for continuously synthesizing dimethyl sulfoxide in a kettle, continuously synthesizing dimethyl sulfoxide products with high content and high yield, without using tubular reactors or plate tower reactors, realizing the continuous synthesis of dimethyl sulfoxide by using a reaction kettle, significantly improving the synthesis efficiency, having low process implementation costs, few side reactions, and no pollution emissions, and being very suitable as a process route for industrial production of dimethyl sulfoxide.
[0006] The technical solution adopted by the present invention is as follows: A method for continuously synthesizing dimethyl sulfoxide in a kettle, comprising the following operating steps: S1. Continuously feed dimethyl sulfide and hydrogen peroxide into a mixer according to a molar ratio of 0.95 - 3:1 to obtain a mixed material; S2. Continuously feed the mixed material obtained in the above step S1 into a first reaction kettle, keeping the first reaction kettle not exceeding the highest liquid volume limit value, and performing a preliminary reaction under the conditions of a temperature of 5 - 25 °C and stirring to obtain a preliminary reactant; S3. Continuously feed the preliminary reactant obtained in the above step S2 into a second reaction kettle, keeping the second reaction kettle not exceeding the highest liquid volume limit value, and performing a reaction under the conditions of a temperature of 5 - 25 °C and stirring to obtain a dimethyl sulfoxide product; S4. Feed the dimethyl sulfoxide product obtained in the above step S3 into a product collection tank.
[0007] Preferably, in the above step S1, the molar ratio of dimethyl sulfide to hydrogen peroxide is 1 - 1.5:1, more preferably 1.05 - 1.08:1.
[0008] Preferably, in the above step S2, the stirring speed of the first reactor is 50 - 70 r / min, and the temperature is set at 10 - 20 °C; in the above step S3, the stirring speed of the second reactor is 50 - 70 r / min, and the temperature is set at 10 - 20 °C.
[0009] Preferably, the maximum limit of the liquid volume of the first reactor is 1 - 4 times, more preferably 1 - 3 times, the hourly feed flow rate of the first reactor; the maximum limit of the liquid volume of the second reactor is 1 - 4 times, more preferably 1 - 3 times, the hourly feed flow rate of the second reactor.
[0010] Preferably, the operating parameters of the first reactor are the same as those of the second reactor; the time for the material in the first reactor to reach its maximum liquid volume limit from none is 1 - 4 hours.
[0011] Preferably, the purity of the dimethyl sulfoxide product is not less than 90%, and its yield is not less than 85%; more preferably, the purity of the dimethyl sulfoxide product is not less than 95%, and its yield is not less than 90%.
[0012] Preferably, a device used for the continuous synthesis of dimethyl sulfoxide in a kettle according to the above method includes a dimethyl sulfide raw material tank, a hydrogen peroxide raw material tank, a mixer, a first reactor, and a second reactor; wherein, the dimethyl sulfide raw material tank and the hydrogen peroxide raw material tank are respectively connected to the mixer through a dimethyl sulfide raw material pipeline and a hydrogen peroxide pipeline; The outlet of the mixer is connected to the inlet of the first reactor; The bottom outlet of the first reactor is connected to the inlet of the second reactor; The bottom outlet of the second reactor is connected to the product collection tank.
[0013] Preferably, a dimethyl sulfide metering pump and a hydrogen peroxide metering pump are respectively provided on the dimethyl sulfide raw material pipeline and the hydrogen peroxide pipeline to respectively control the feeding flow rates of dimethyl sulfide and hydrogen peroxide; a first metering pump is provided on the pipeline connecting the first reaction kettle and the second reaction kettle. When the liquid volume in the first reaction kettle exceeds the corresponding maximum limit value, the first metering pump is started to keep the liquid volume in the first reaction kettle from exceeding the corresponding maximum limit value; a second metering pump is provided on the pipeline connecting the second reaction kettle and the product collection tank. When the liquid volume in the second reaction kettle exceeds the corresponding maximum limit value, the second metering pump is started to keep the liquid volume in the second reaction kettle from exceeding the corresponding maximum limit value.
[0014] Preferably, a first stirrer and a second stirrer are respectively installed on the first reaction kettle and the second reaction kettle.
[0015] Preferably, a first refrigerant jacket and a second refrigerant jacket are respectively provided on the first reaction kettle and the second reaction kettle, and refrigerants at 5-25°C are respectively introduced into the first refrigerant jacket and the second refrigerant jacket to cool each reaction kettle.
[0016] The present application proposes a kettle-type continuous synthesis route of dimethyl sulfoxide mainly composed of a first reaction kettle and a second reaction kettle connected in sequence. After mixing dimethyl sulfide and hydrogen peroxide according to the designed molar ratio, they are continuously fed into the first reaction kettle, and a preliminary reaction is carried out on the premise of keeping the liquid volume in the first reaction kettle from exceeding the maximum limit value. Then, the preliminary reaction product is continuously fed into the second reaction kettle, and a reaction is carried out on the premise of keeping the liquid volume in the second reaction kettle from exceeding the maximum limit value. Finally, a dimethyl sulfoxide product with high content and high yield is continuously synthesized. There is no need to use a shell-and-tube reactor or a plate-tower reactor. The reaction kettle is used to realize the continuous synthesis of dimethyl sulfoxide, the synthesis efficiency is significantly improved, the process implementation cost is low, the side reactions are few, and there is no pollution discharge. It is very suitable as a process route for industrial production of dimethyl sulfoxide. Brief Description of the Drawings
[0017] Figure 1 It is a schematic diagram of the device connection structure for kettle-type continuous synthesis of dimethyl sulfoxide under the specific embodiment of the present invention. Specific Embodiment
[0018] Please refer to Figure 1As shown in the figure, this embodiment provides a device for continuous synthesis of dimethyl sulfoxide in a kettle, including a dimethyl sulfide raw material tank 1, a hydrogen peroxide raw material tank 2, a mixer 3 (preferably a static mixer), a first reaction kettle 4 and a second reaction kettle 5; among them, the dimethyl sulfide raw material tank 1 and the hydrogen peroxide raw material tank 2 are respectively connected to the mixer 3 through a dimethyl sulfide raw material pipeline 1a and a hydrogen peroxide pipeline 2a; the outlet of the mixer 3 is connected to the inlet of the first reaction kettle 4; the bottom outlet of the first reaction kettle 4 is connected to the inlet of the second reaction kettle 5; the bottom outlet of the second reaction kettle 5 is connected to a product collection tank 6; Preferably, in this embodiment, a dimethyl sulfide metering pump 7a and a hydrogen peroxide metering pump 7b are respectively provided on the dimethyl sulfide raw material pipeline 1a and the hydrogen peroxide pipeline 1b to respectively control the feeding flow rates of dimethyl sulfide and hydrogen peroxide; a first metering pump 8a is provided on the connecting pipeline between the first reaction kettle 4 and the second reaction kettle 5; a second metering pump 8b is provided on the connecting pipeline between the second reaction kettle 5 and the product collection tank 6.
[0019] Preferably, in this embodiment, a first stirrer 4a and a second stirrer 5a are respectively installed in the first reaction kettle 4 and the second reaction kettle 5; the first reaction kettle 4 and the second reaction kettle 5 are respectively provided with a first refrigerant jacket 4b and a second refrigerant jacket 5b, and a refrigerant at 5-25°C is introduced into the first refrigerant jacket 4b and the second refrigerant jacket 5b respectively to realize the cooling of the reaction kettles 4 and 5; Based on the above device for continuous synthesis of dimethyl sulfoxide in a kettle, this embodiment further proposes a method for continuous synthesis of dimethyl sulfoxide in a kettle, including the following operating steps: S1. Continuously feed dimethyl sulfide and hydrogen peroxide into the mixer 3 according to a molar ratio of 0.95-3:1 to obtain a mixed material; preferably, in this step S1, the molar ratio of dimethyl sulfide to hydrogen peroxide is 1-1.5:1, more preferably 1.05-1.08:1, and most preferably 1.05:1; S2. Continuously feed the mixed material obtained in the above step S1 into the first reaction kettle 4, keeping the first reaction kettle 4 not exceeding the maximum liquid volume limit. Conduct a preliminary reaction under the conditions of a temperature of 5 - 25°C and stirring to obtain a preliminary reaction product. Among them, when the first reaction kettle 4 exceeds its corresponding maximum liquid volume limit, turn on the first metering pump 8a so that the first reaction kettle 4 remains not exceeding its corresponding maximum liquid volume limit. Preferably, in this step S2, the stirring speed of the first reaction kettle 4 is 50 - 70 r / min, more preferably 55 - 65 r / min; the temperature is set to 10 - 20°C; the maximum liquid volume limit of the first reaction kettle 4 is 1 - 4 times, more preferably 1 - 3 times, the hourly feed flow rate of the first reaction kettle 4; the feed flow rate of the mixed material into the first reaction kettle 4 is controlled at 0.5 - 3 L / hour, more preferably 1 - 2 L / hour. S3. Continuously feed the preliminary reaction product obtained in the above step S2 into the second reaction kettle 5, keeping the second reaction kettle 5 not exceeding the maximum liquid volume limit. Conduct a reaction under the conditions of a temperature of 5 - 25°C and stirring to obtain a dimethyl sulfoxide product. Among them, when the second reaction kettle 5 exceeds its corresponding maximum liquid volume limit, turn on the second metering pump 8b so that the second reaction kettle 5 remains not exceeding its corresponding maximum liquid volume limit. Preferably, in this step S3, the stirring speed of the second reaction kettle 5 is 50 - 70 r / min, more preferably 55 - 65 r / min; the temperature is more preferably set to 10 - 20°C; the maximum liquid volume limit of the second reaction kettle 5 is 1 - 4 times, more preferably 1 - 3 times, the hourly feed flow rate of the second reaction kettle; the feed flow rate from the first reaction kettle 4 to the second reaction kettle 5 is controlled at 0.5 - 3 L / hour, more preferably 1 - 2 L / hour. Preferably, in this embodiment, the operating parameters of the first reaction kettle 4 are the same as those of the second reaction kettle 5; the time for the material in the first reaction kettle 4 to reach its maximum liquid volume limit from none is 1 - 4 hours, and the time for the material in the second reaction kettle 5 to reach its maximum liquid volume limit from none is 1 - 4 hours. S4. Feed the dimethyl sulfoxide product obtained in the above step S3 into the product collection tank 6. Preferably, in this embodiment, the purity of the dimethyl sulfoxide product is not less than 90%, and its yield is not less than 85%; more preferably, the purity of the dimethyl sulfoxide product is not less than 95%, and its yield is not less than 90%.
[0020] It should be noted that when implementing this application, an inert gas (such as nitrogen) is first introduced to purge the device to completely expel the air in the device, preventing the formation of an explosive mixture of dimethyl sulfide raw material and air. These are common general knowledge for those skilled in the art and will not be specifically elaborated in this embodiment. It should also be noted that when implementing this application, if the temperature in each reaction kettle is too low (for example, less than 5°C), it will be unfavorable for the reaction efficiency; if the temperature in each reaction kettle is too high (for example, greater than 25°C), it will cause the volatilization of dimethyl sulfide, resulting in a large pressure in the reaction kettle, and thus a potential safety hazard.
[0021] In order to enable those skilled in the art to better understand the technical solutions in this invention, the following will clearly and completely describe the technical solutions in the embodiments of this invention in conjunction with the accompanying drawings in the embodiments of this invention. Obviously, the described embodiments are only a part of the embodiments of this invention, rather than all of the embodiments. Based on the embodiments in this invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this invention.
[0022] Based on the above-described implementation schemes, the following specific embodiments are further proposed in this application: It should be noted that the mixer 3 used in the following specific embodiments of this invention is a laboratory SK-type static mixer, and its relevant parameter specifications are as follows: Inner diameter 10 mm, length 150 mm, with spiral blades twisted 180° left and right inside, welded crosswise at 90°; The first reaction kettle 4 and the second reaction kettle 4 are the same, and their relevant parameter specifications are both: diameter 20 cm, height 20 cm, maximum volume 6 L.
[0023] Example 1: The following operation process is carried out: First, introduce nitrogen to purge the air in the device; start the dimethyl sulfide metering pump 7a and the hydrogen peroxide metering pump 7b, and feed dimethyl sulfide and hydrogen peroxide according to a molar ratio of 1.05:1, with the total feed rate of the raw materials being 1.5 L / hour; After sending the raw materials into the mixer 3 to obtain a mixed material, then feed the mixed material into the first reaction kettle 4 at a feed flow rate of 1.5 L / hour. Control the temperature in the first reaction kettle 4 at 20°C through a refrigerant, turn on the first stirrer 4a, set the rotation speed to 60 r / min, and keep the maximum liquid volume limit in the first reaction kettle 4 at 1.5 L. The residence time of the material in the first reaction kettle 4 is 1 hour; Turn on the first metering pump 8a to transfer the preliminary reaction product into the second reaction kettle 5. The operating parameters of the second reaction kettle 5 are set exactly the same as those of the first reaction kettle 4, and the residence time of the material in the second reaction kettle 5 is 1 hour; Then, start the second metering pump 8b to transfer the dimethyl sulfoxide product into the product collection tank 6. The collected product is a mixed liquid of water and dimethyl sulfoxide. The preliminary reactant and the dimethyl sulfoxide product were respectively detected using gas chromatography FID. The detection results are as follows: the purity of dimethyl sulfoxide in the preliminary reactant (from the first reaction kettle 4) is 65.32%, and the yield of dimethyl sulfoxide is 60.16%; the purity of the dimethyl sulfoxide product (from the second reaction kettle 5) is 96.24%, and the yield is 91.07%.
[0024] Example 2: The following operation process is carried out: First, introduce nitrogen to purge the air in the device; start the dimethyl sulfide metering pump 7a and the hydrogen peroxide metering pump 7b, and feed dimethyl sulfide and hydrogen peroxide according to a molar ratio of 1.05:1. The total feed rate of the raw materials is 2 L / hour; After feeding the raw materials into the mixer 3, the mixed material is obtained, and then the mixed material is fed into the first reaction kettle 4 at a feed flow rate of 2 L / hour. The temperature in the first reaction kettle 4 is controlled at 15 °C by refrigerant. Start the first stirrer 4a, and set the rotation speed to 60 r / min. Keep the maximum liquid volume limit in the first reaction kettle 4 at 4 L, and the residence time of the material in the first reaction kettle 4 is 2 hours; Start the first metering pump 8a to transfer the preliminary reactant into the second reaction kettle 5. The operating parameters of the second reaction kettle 5 are completely set the same as those of the first reaction kettle 4, and the residence time of the material in the second reaction kettle 5 is 2 hours; Then, start the second metering pump 8b to transfer the dimethyl sulfoxide product into the product collection tank 6. The collected product is a mixed liquid of water and dimethyl sulfoxide. The preliminary reactant and the dimethyl sulfoxide product were respectively detected using gas chromatography FID. The detection results are as follows: the purity of dimethyl sulfoxide in the preliminary reactant (from the first reaction kettle 4) is 72.46%, and the yield of dimethyl sulfoxide is 66.91%; the purity of the dimethyl sulfoxide product (from the second reaction kettle 5) is 98.15%, and the yield is 93.36%.
[0025] Example 3: The following operation process is carried out: First, introduce nitrogen to purge the air in the device; start the dimethyl sulfide metering pump 7a and the hydrogen peroxide metering pump 7b, and feed dimethyl sulfide and hydrogen peroxide according to a molar ratio of 1.05:1. The total feed rate of the raw materials is 1 L / hour; After feeding the raw materials into the mixer 3, the mixed material is obtained, and then the mixed material is fed into the first reaction kettle 4 at a feed flow rate of 1 L / hour. The temperature in the first reaction kettle 4 is controlled at 5 °C by refrigerant. Start the first stirrer 4a, and set the rotation speed to 60 r / min. Keep the maximum liquid volume limit in the first reaction kettle 4 at 3 L, and the residence time of the material in the first reaction kettle 4 is 3 hours; Start the first metering pump 8a to transfer the preliminary reactants into the second reaction kettle 5. The operating parameters of the second reaction kettle 5 are set exactly the same as those of the first reaction kettle 4. The residence time of the materials in the second reaction kettle 5 is 3 hours. Then start the second metering pump 8b to transfer the dimethyl sulfoxide product into the product collection tank 6. The collected product is a mixed liquid of water and dimethyl sulfoxide. The preliminary reactants and the dimethyl sulfoxide product were respectively detected using gas chromatography FID. The detection results are as follows: the purity of dimethyl sulfoxide in the preliminary reactants (from the first reaction kettle 4) is 75.39%, and the yield of dimethyl sulfoxide is 69.58%; the purity of the dimethyl sulfoxide product (from the second reaction kettle 5) is 97.54%, and the yield is 92.75%.
[0026] Example 4: According to the following operation process: First, introduce nitrogen to purge the air in the device; start the dimethyl sulfide metering pump 7a and the hydrogen peroxide metering pump 7b, and feed the dimethyl sulfide and hydrogen peroxide according to a molar ratio of 1:1. The total feed rate of the raw materials is 2 L / hour. After feeding the raw materials into the mixer 3, the mixed materials are obtained, and then the mixed materials enter the first reaction kettle 4 at a feed flow rate of 2 L / hour. The temperature in the first reaction kettle 4 is controlled at 15 °C by the refrigerant. Start the first stirrer 4a, and set the rotation speed to 60 r / min. Keep the maximum liquid volume limit in the first reaction kettle 4 at 4 L. The residence time of the materials in the first reaction kettle 4 is 2 hours. Start the first metering pump 8a to transfer the preliminary reactants into the second reaction kettle 5. The operating parameters of the second reaction kettle 5 are set exactly the same as those of the first reaction kettle 4. The residence time of the materials in the second reaction kettle 5 is 2 hours. Then start the second metering pump 8b to transfer the dimethyl sulfoxide product into the product collection tank 6. The collected product is a mixed liquid of water and dimethyl sulfoxide. The preliminary reactants and the dimethyl sulfoxide product were respectively detected using gas chromatography FID. The detection results are as follows: the purity of dimethyl sulfoxide in the preliminary reactants (from the first reaction kettle 4) is 73.69%, and the yield of dimethyl sulfoxide is 68.21%; the purity of the dimethyl sulfoxide product (from the second reaction kettle 5) is 95.24%, and the yield is 86.95%.
[0027] Example 5: According to the following operation process: First, introduce nitrogen to purge the air in the device; start the dimethyl sulfide metering pump 7a and the hydrogen peroxide metering pump 7b, and feed the dimethyl sulfide and hydrogen peroxide according to a molar ratio of 1:1.05. The total feed rate of the raw materials is 2 L / hour. After feeding the raw materials into the mixer 3, a mixed material is obtained. Then, the mixed material is fed into the first reaction kettle 4 at a feeding flow rate of 2 L / h. The temperature inside the first reaction kettle 4 is controlled at 15 °C by a refrigerant. The first stirrer 4a is started, and the rotation speed is set at 60 r / min. The maximum limit of the liquid volume inside the first reaction kettle 4 is maintained at 4 L, and the residence time of the material inside the first reaction kettle 4 is 2 hours. Start the first metering pump 8a to transfer the preliminary reactant into the second reaction kettle 5. The operating parameters of the second reaction kettle 5 are set exactly the same as those of the first reaction kettle 4, and the residence time of the material inside the second reaction kettle 5 is 2 hours. Then start the second metering pump 8b to transfer the dimethyl sulfoxide product into the product collection tank 6. The collected product is a mixed liquid of water and dimethyl sulfoxide. The preliminary reactant and the dimethyl sulfoxide product are respectively detected using a gas chromatograph FID. The detection results are as follows: the purity of dimethyl sulfoxide in the preliminary reactant (from the first reaction kettle 4) is 65.92%, and the yield of dimethyl sulfoxide is 59.61%; the purity of the dimethyl sulfoxide product (from the second reaction kettle 5) is 91.89%, and the yield is 85.79%.
[0028] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.
[0029] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for continuous synthesis of dimethyl sulfoxide in a kettle, characterized in that, It includes the following operating steps: S1. Continuously feed dimethyl sulfide and hydrogen peroxide into a mixer at a molar ratio of 0.95 - 3:1 to obtain a mixed material; S2. Continuously feed the mixed material obtained in step S1 above into a first reaction kettle, keeping the liquid volume in the first reaction kettle not exceeding the highest limit value, and carry out a preliminary reaction under the conditions of a temperature of 5 - 25°C and stirring to obtain a preliminary reactant; S3. Continuously feed the preliminary reactant obtained in step S2 above into a second reaction kettle, keeping the liquid volume in the second reaction kettle not exceeding the highest limit value, and carry out a reaction under the conditions of a temperature of 5 - 25°C and stirring to obtain a dimethyl sulfoxide product; S4. Feed the dimethyl sulfoxide product obtained in step S3 above into a product collection tank.
2. The method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 1, wherein, In step S1, the molar ratio of dimethyl sulfide to hydrogen peroxide is 1 - 1.5:1, more preferably 1.05 - 1.08:
1.
3. The method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 1, characterized in that, In step S2, the stirring speed of the first reaction kettle is 50 - 70 r / min, and the temperature is set at 10 - 20°C; in step S3, the stirring speed of the second reaction kettle is 50 - 70 r / min, and the temperature is set at 10 - 20°C.
4. The method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 1, characterized in that, The highest limit value of the liquid volume of the first reaction kettle is 1 - 4 times, more preferably 1 - 3 times, of the hourly feed flow rate of the first reaction kettle; the highest limit value of the liquid volume of the second reaction kettle is 1 - 4 times, more preferably 1 - 3 times, of the hourly feed flow rate of the second reaction kettle.
5. The method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 1 or 4, characterized in that, The operating parameters of the first reaction kettle are the same as those of the second reaction kettle; the time for the material in the first reaction kettle to reach its highest liquid volume limit value from zero is 1 - 4 hours.
6. The method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 1, characterized in that, The purity of the dimethyl sulfoxide product is not less than 90%, and its yield is not less than 85%; more preferably, the purity of the dimethyl sulfoxide product is not less than 95%, and its yield is not less than 90%.
7. An apparatus used in the method for continuously synthesizing dimethyl sulfoxide in a kettle according to any one of claims 1-6, characterized in that, It includes a dimethyl sulfide raw material tank, a hydrogen peroxide raw material tank, a mixer, a first reaction kettle and a second reaction kettle; among them, the dimethyl sulfide raw material tank and the hydrogen peroxide raw material tank are respectively connected to the mixer through a dimethyl sulfide raw material pipeline and a hydrogen peroxide pipeline; The outlet of the mixer is connected to the inlet of the first reaction kettle; The bottom outlet of the first reaction kettle is connected to the inlet of the second reaction kettle; The bottom outlet of the second reaction kettle is connected to the product collection tank.
8. The apparatus used in the method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 7, characterized in that, Dimethyl sulfide metering pumps and hydrogen peroxide metering pumps are respectively provided on the dimethyl sulfide raw material pipeline and the hydrogen peroxide pipeline to respectively control the feed flow rates of dimethyl sulfide and hydrogen peroxide; a first metering pump is provided on the pipeline connecting the first reaction kettle and the second reaction kettle. When the first reaction kettle exceeds its corresponding highest liquid volume limit value, the first metering pump is turned on to keep the first reaction kettle from exceeding its corresponding highest liquid volume limit value; a second metering pump is provided on the pipeline connecting the second reaction kettle and the product collection tank. When the second reaction kettle exceeds its corresponding highest liquid volume limit value, the second metering pump is turned on to keep the second reaction kettle from exceeding its corresponding highest liquid volume limit value.
9. The apparatus used in the method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 7 or 8, characterized in that, The first reactor and the second reactor are respectively equipped with a first stirrer and a second stirrer.
10. The device used in the method for continuously synthesizing dimethyl sulfoxide in a kettle according to claim 7 or 8, characterized in that, The first reactor and the second reactor are respectively provided with a first refrigerant jacket and a second refrigerant jacket, and a refrigerant at 5 - 25 °C is respectively introduced into the first refrigerant jacket and the second refrigerant jacket to achieve cooling of each reactor.