Reaction device for methyl 2, 3-dichloropropionate

Abstract

The utility model relates to a reaction device for methyl 2, 3-dichloropropionate, which belongs to the technical field of production of methyl 2, 3-dichloropropionate and comprises a reactor, upper rotary density measuring instruments are fixedly mounted on the inner wall of the left side and the inner wall of the right side of the reactor, and one end of each upper rotary density measuring instrument penetrates through the reactor and extends to the outside of the reactor. Middle rotary density measuring instruments of which one ends penetrate through the reactor and extend out of the reactor are fixedly mounted on the inner wall of the left side and the inner wall of the right side of the reactor. According to the reaction device for methyl 2, 3-dichloropropionate, under the action of the upper rotary density measuring instrument, the middle rotary density measuring instrument and the lower rotary density measuring instrument, online monitoring, detection and precise pre-separation of reaction liquid and byproduct polymerization waste liquid are achieved, meanwhile, finished products and byproducts are stored separately, the production efficiency is improved, and the production cost is reduced. The maintenance intensity is greatly reduced, the energy consumption and the operation time of secondary fractionation are saved, the byproduct polymerization waste material, the regular distillation recovery product and the waste material are uniformly treated, and the unit consumption of the product is reduced.

Description

Technical Field

[0001] This utility model relates to the field of methyl 2,3-dichloropropionate production technology, specifically to a reaction apparatus for methyl 2,3-dichloropropionate. Background Technology

[0002] 2,3-Dichloropropionate is a pharmaceutical and pesticide intermediate, synthesized from methanol and acrylonitrile. Currently, the most common method is to react methyl acrylate with methanol and chlorine to obtain 2,3-dichloropropionate. However, after a long period of production, a certain amount of polymer will accumulate in the product.

[0003] Existing polymer enrichment in the product, without secondary fractionation and separation, directly feeding it into the next process will clog pipes and packing distributors, affecting not only the yield but also the quality of the product in the next process. Furthermore, without regular cleaning, the polymer will adhere to the bottom of the reactor, making it difficult to remove completely. Consequently, after a certain period of time, the single-batch yield of methyl 2,3-dichloropropionate will decrease and fluctuate. Therefore, a reaction device for methyl 2,3-dichloropropionate is proposed to solve the above problems. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a reaction apparatus for methyl 2,3-dichloropropionate, which has the advantage of improving production efficiency. It solves the problem that in existing processes, polymers accumulate in the product, and without secondary fractionation and separation, they are directly added to the next process, which can clog pipes and packing distributors, affecting not only the yield but also the quality of the product in the next process. Furthermore, without regular cleaning, polymers will adhere to the bottom of the reactor, making them difficult to remove completely. Consequently, the single-batch yield of methyl 2,3-dichloropropionate will decrease and fluctuate after a certain period of time.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a reaction apparatus for methyl dichloropropionate, comprising a reactor, wherein an upper rotary density measuring instrument is fixedly installed on both the left and right inner walls of the reactor, with one end penetrating the reactor and extending to its exterior.

[0006] A central rotary density measuring instrument, penetrating the reactor and extending to the outside, is fixedly installed on both the left and right inner walls of the reactor. A lower rotary density measuring instrument, penetrating the reactor and extending to the outside, is also fixedly installed on both the left and right inner walls of the reactor. A discharge valve is fixedly installed at the bottom of the reactor. A chlorine gas cylinder is placed on the left side of the reactor, and a condenser is placed on the right side of the reactor.

[0007] The reactor is equipped with a conveying assembly for conveying the reacted materials.

[0008] Furthermore, the reactor is a reaction vessel, and the length-to-diameter ratio of the reactor is three to thirty, preferably three to five.

[0009] Furthermore, the upper rotary density measuring instrument, the middle rotary density measuring instrument, and the lower rotary density measuring instrument are all dynamically sealed explosion-proof structures made of ceramic material, and their measuring probes are all located inside the reactor.

[0010] Furthermore, the conveying assembly includes a first connecting pipe, one end of which is fixedly connected to the output end of a chlorine cylinder, and the other end of which is fixedly installed with a chlorine filter. The output end of the chlorine filter is fixedly connected to a second connecting pipe, one end of which penetrates the reactor and extends into its interior. A first conveying pipe is fixedly installed on the inner top wall of the reactor. The end of the first conveying pipe away from the reactor is fixedly connected to the input end of a condenser. A second conveying pipe is fixedly installed on the output end of the condenser. A three-stage tail gas absorption device is fixedly installed on the end of the second conveying pipe away from the reactor. A third conveying pipe, one end of which penetrates the reactor and extends into its right side, is fixedly connected to the inner wall of the right side of the reactor. A finished product storage tank is fixedly installed on the end of the third conveying pipe away from the reactor. A reactor polymerization product collection tank is placed on the left side of the finished product storage tank. A fourth conveying pipe, one end of which penetrates the reactor polymerization product collection tank and extends into its interior, is fixedly installed on the output end of the discharge valve.

[0011] Furthermore, the second connecting pipe is fixedly connected to the reactor, and the fourth conveying pipe is fixedly connected to the reactor polymerization product collection tank.

[0012] Furthermore, the discharge valve is cascaded, with a stop valve, a ball valve, and a check valve connected in series.

[0013] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0014] The reaction apparatus for methyl 2,3-dichloropropionate, through the operation of an upper, middle, and lower rotary density measuring instrument, achieves online monitoring, detection, and precise pre-separation of the reaction liquid and by-product polymerization waste liquid. At the same time, the finished product and by-product are stored separately, improving production efficiency, significantly reducing maintenance intensity, saving energy consumption and operation time for secondary fractionation, and periodically distilling and recovering products from the by-product polymerization waste. The waste is disposed of in a unified manner, reducing the unit consumption of the product. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] In the diagram: 1 Reactor, 2 Upper rotary density meter, 3 Middle rotary density meter, 4 Lower rotary density meter, 5 Discharge valve, 6 Chlorine cylinder, 7 Chlorine filter, 8 Condenser, 9 Three-stage tail gas absorption device, 10 Reactor polymerization product collection tank, 11 Finished product storage tank, 12 First conveying pipe, 13 Second conveying pipe, 14 Third conveying pipe, 15 Fourth conveying pipe, 16 Second connecting pipe, 17 First connecting pipe. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Please see Figure 1 The reaction apparatus for methyl 2,3-dichloropropionate in this embodiment includes a reactor 1. An upper rotary density measuring instrument 2 is fixedly installed on both the left and right inner walls of the reactor 1, with one end penetrating the reactor 1 and extending to its exterior.

[0019] A central rotary density measuring instrument 3 is fixedly installed on both the left and right inner walls of reactor 1, with one end penetrating reactor 1 and extending to its outside. A lower rotary density measuring instrument 4 is fixedly installed on both the left and right inner walls of reactor 1, with one end penetrating reactor 1 and extending to its outside. A discharge valve 5 is fixedly installed at the bottom of reactor 1. A chlorine gas cylinder 6 is placed on the left side of reactor 1, and a condenser 8 is placed on the right side of reactor 1.

[0020] Among them, reactor 1 is a reaction vessel, and the length-to-diameter ratio of reactor 1 is three to thirty, preferably three to five. The upper rotary density measuring instrument 2, the middle rotary density measuring instrument 3, and the lower rotary density measuring instrument 4 are all ceramic material dynamic sealing explosion-proof structures, and their measuring probes are all located inside reactor 1. The design size of reactor 1 is a cylinder with a diameter of 1 meter and a length of 5 meters.

[0021] It should be noted that the upper rotary density measuring instrument 2, the middle rotary density measuring instrument 3, the lower rotary density measuring instrument 4, and the condenser 8 are all conventional devices known to the public in the prior art, and their specific structures and working principles will not be described in detail in this article.

[0022] Specifically, chlorine gas is stored inside chlorine cylinder 6. The chlorine gas enters the reactor 1 to react. At the beginning of the reaction, the specific gravity of the upper, middle and lower parts of the reactor 1 is the same. As the reaction proceeds, especially during the continuous reaction stage with increased temperature, the specific gravity of the liquid in the upper, middle and lower parts of the reactor 1 will change. The internal density of the reactor 1 is monitored by the upper rotary density measuring instrument 2, the middle rotary density measuring instrument 3 and the lower rotary density measuring instrument 4.

[0023] The reactor 1 is equipped with a conveying assembly, which includes a first connecting pipe 17. One end of the first connecting pipe 17 is fixedly connected to the output end of the chlorine cylinder 6, and the other end is fixedly installed with a chlorine filter 7. The output end of the chlorine filter 7 is fixedly connected to a second connecting pipe 16 that passes through the reactor 1 and extends into it. The inner top wall of the reactor 1 is fixedly installed with a first conveying pipe 12. The end of the first conveying pipe 12 away from the reactor 1 is fixedly connected to the input end of the condenser 8. The output end of the condenser 8 is fixedly installed with a second conveying pipe 13. The end of the second conveying pipe 13 away from the reactor 1 is fixedly installed with a three-stage tail gas absorption device 9. The right inner wall of the reactor 1 is fixedly connected with a third conveying pipe 14 that passes through the reactor 1 and extends into it. The end of the third conveying pipe 14 away from the reactor 1 is fixedly installed with a finished product storage tank 11. The left side of the finished product storage tank 11 is placed with a reactor polymerization product collection tank 10. The output end of the discharge valve 5 is fixedly installed with a fourth conveying pipe 15 that passes through the reactor polymerization product collection tank 10 and extends into it.

[0024] The second connecting pipe 16 is fixedly connected to the reactor 1, the fourth conveying pipe 15 is fixedly connected to the reactor polymerization product collection tank 10, the discharge valve 5 adopts a 2 to 3-stage connection, and the stop valve, ball valve and check valve are connected in series.

[0025] It should be noted that the chlorine filter 7 and the three-stage tail gas absorption device 9 are both conventional devices known to the public in the prior art, and their specific structures and working principles will not be described in detail in this article.

[0026] Specifically, chlorine gas is stored inside chlorine cylinder 6. Through the output of the first connecting pipe 17, the chlorine gas enters the chlorine filter 7, where it is filtered. Then, through the second connecting pipe 16, the chlorine gas enters the reactor 1 for reaction. When the specific gravity of the liquid at the bottom of reactor 1 is greater than 1, it indicates that a considerable concentration of polymerization product has accumulated in the lower part of reactor 1. After the batch reaction is completed and the mixture has been allowed to stand for a period of time, the specific gravity of the middle and upper parts of reactor 1 should be approximately the same, and the specific gravity of the material at the bottom of reactor 1 should stabilize at or above 1. Then, the material is discharged through the discharge valve. Under the action of door 5 and the fourth conveying pipe 15, the enriched polymer is discharged into the reactor polymerization product collection tank 10 for unified processing. The upper and middle materials are transferred to the finished product storage tank 11 through the third conveying pipe 14. The gas phase detection purity is 96-98%, which can be directly carried out in the next process without purification. The first-pass yield of the product is significantly improved and stabilized. Under the action of the first conveying pipe 12, the tail gas is transported into the interior of the condenser 8 to cool the tail gas. Then, under the action of the second conveying pipe 13, the tail gas is transported into the interior of the three-stage tail gas absorption device 9 to absorb the tail gas.

[0027] The working principle of the above embodiments is as follows:

[0028] Chlorine gas is stored inside chlorine cylinder 6. Through the output of the first connecting pipe 17, the chlorine gas enters the chlorine filter 7, where it is filtered. Then, through the second connecting pipe 16, the chlorine gas enters the reactor 1 to react. At the beginning of the reaction, the specific gravity of the upper, middle, and lower parts of reactor 1 is the same. As the reaction progresses, especially during the sustained reaction phase with increased temperature, the specific gravity of the liquid in each part of reactor 1 changes. The internal density of reactor 1 is monitored using the upper rotary density meter 2, the middle rotary density meter 3, and the lower rotary density meter 4. When the specific gravity of the liquid in the lower part of reactor 1 is greater than 1, it indicates that a considerable concentration of polymerization product has accumulated in the lower part of reactor 1, and this product needs to be removed from the reactor. After the reaction is completed and the mixture has been allowed to stand for a period of time, the specific gravity of the middle and upper parts of reactor 1 is basically the same. When the specific gravity of the material at the bottom of reactor 1 is stable at 1 or above, the enriched polymer is discharged into the reactor polymerization product collection tank 10 through the discharge valve 5 and the fourth conveying pipe 15 for unified processing. The material in the middle and upper parts is transferred to the finished product storage tank 11 through the third conveying pipe 14. The purity of the gas phase is 96-98%, which can be directly carried out in the next process without purification. The first-pass yield of the product is significantly and stably improved. The tail gas is transported into the condenser 8 through the first conveying pipe 12 to cool the tail gas. Then, the tail gas is transported into the three-stage tail gas absorption device 9 through the second conveying pipe 13 to absorb the tail gas.

[0029] The control method of this utility model is through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the field. Since this utility model is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail.

[0030] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reaction apparatus for methyl 2,3-dichloropropionate, comprising a reactor (1), characterized in that: A top rotary density measuring instrument (2) is fixedly installed on both the left and right inner walls of the reactor (1), with one end penetrating the reactor (1) and extending to its outside. A central rotary density measuring instrument (3) with one end penetrating the reactor (1) and extending to the outside is fixedly installed on the left inner wall and the right inner wall of the reactor (1). A lower rotary density measuring instrument (4) with one end penetrating the reactor (1) and extending to the outside is fixedly installed on the left inner wall and the right inner wall of the reactor (1). A discharge valve (5) is fixedly installed at the bottom of the reactor (1). A chlorine gas cylinder (6) is placed on the left side of the reactor (1). A condenser (8) is placed on the right side of the reactor (1). The reactor (1) is equipped with a conveying assembly for conveying the reacted materials.

2. The reaction apparatus for methyl 2,3-dichloropropionate according to claim 1, characterized in that: The reactor (1) is a reaction vessel, and the length to diameter ratio of the reactor (1) is three to thirty.

3. The reaction apparatus for methyl 2,3-dichloropropionate according to claim 2, characterized in that: The upper rotary density measuring instrument (2), the middle rotary density measuring instrument (3) and the lower rotary density measuring instrument (4) are all ceramic material dynamic sealing explosion-proof structures, and their measuring probes are all located inside the reactor (1).

4. The reaction apparatus for methyl 2,3-dichloropropionate according to claim 1, characterized in that: The conveying assembly includes a first connecting pipe (17), one end of which is fixedly connected to the output end of a chlorine cylinder (6), and the other end of which is fixedly installed with a chlorine filter (7). The output end of the chlorine filter (7) is fixedly connected to a second connecting pipe (16) that passes through the reactor (1) and extends into it. The inner top wall of the reactor (1) is fixedly installed with a first conveying pipe (12), the end of the first conveying pipe (12) away from the reactor (1) is fixedly connected to the input end of a condenser (8), and the output end of the condenser (8) is fixedly installed with a second conveying pipe (13). A three-stage tail gas absorption device (9) is fixedly installed at the end of the second conveying pipe (13) away from the reactor (1). A third conveying pipe (14) is fixedly connected to the inner wall of the right side of the reactor (1), with one end penetrating the reactor (1) and extending to its right side. A finished product storage tank (11) is fixedly installed at the end of the third conveying pipe (14) away from the reactor (1). A reactor polymerization product collection tank (10) is placed on the left side of the finished product storage tank (11). A fourth conveying pipe (15) is fixedly installed at the output end of the discharge valve (5), with one end penetrating the reactor polymerization product collection tank (10) and extending into its interior.

5. The reaction apparatus for methyl 2,3-dichloropropionate according to claim 4, characterized in that: The second connecting pipe (16) is fixedly connected to the reactor (1), and the fourth conveying pipe (15) is fixedly connected to the reactor polymerization product collection tank (10).

6. The reaction apparatus for methyl 2,3-dichloropropionate according to claim 5, characterized in that: The discharge valve (5) is used in a 2-3 stage combination.

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