A mixed chloropyridine continuous distillation device

Abstract

The present invention relates to the field of chloropyridine processing equipment, and discloses a mixed chloropyridine continuous distillation device, including a light-removing tower and a heavy-removing tower, the feed end of the light-removing tower is connected with a preheater, a feed pipeline is connected between the light-removing tower and the heavy-removing tower, a first discharge port is arranged on the upper part of the light-removing tower, and a second discharge port is arranged on the upper part of the heavy-removing tower. The utility model can simultaneously carry out continuous light-removing operation in the light-removing distillation tower while the heavy-removing distillation tower is operating, and compared with the operation mode of first raising the temperature for distillation, then cooling down and repeating the operation mode when a single distillation tower is operating, the operation time is shortened to a certain extent and the efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of chloropyridine processing equipment, and in particular to a mixed chloropyridine continuous distillation device. Background Art

[0002] Pyridine is a six-membered heterocyclic compound containing a nitrogen atom. It is often used as a solvent. In addition, it can be used as a denaturant, dyeing aid, and raw material for synthesizing a series of products (including medicines, disinfectants, dyes, etc.) in industry. Pyridine chlorination reaction has a wide range of applications in the field of organic synthesis, especially in the fields of drugs, pesticides and materials. For example, through the chlorination reaction of pyridine, a series of biologically active chlorinated pyridine derivatives can be synthesized, which can be used as pesticides, anti-tumor drugs, etc.

[0003] High-purity chloropyridine is crucial for its application in the fields of pesticides, medicines, veterinary drugs, etc. However, since chloropyridine may contain incompletely reacted raw materials, by-products, impurities, and different isomers during the synthesis process, it is usually necessary to perform distillation after the synthesis of chloropyridine. By utilizing the different boiling points of each component, the impurities are removed and the chloropyridine product with higher purity is gradually separated through multiple partial vaporization and condensation. At present, when performing the distillation operation of chloropyridine, each kettle material must go through feeding, heating, distillation, cooling, kettle bottom discharge, and then re-feeding and repeating the above operations. This distillation device takes a long time when performing the distillation operation. Summary of the invention

[0004] The present invention aims to provide a mixed chloropyridine continuous distillation device to solve the problems of long operation time and low efficiency in the prior art when performing chloropyridine distillation.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a mixed chloropyridine continuous distillation device, comprising a light-removing tower and a heavy-removing tower, the feed end of the light-removing tower is connected to a preheater, a feed pipeline is connected between the light-removing tower and the heavy-removing tower, a first discharge port is arranged at the top of the light-removing tower, and a second discharge port is arranged at the top of the heavy-removing tower.

[0006] The principle and advantage of this scheme are: in actual application, in this technical scheme, in view of the long operation time and low efficiency in the prior art when performing chloropyridine rectification, the inventor has optimized the structure of the rectification equipment. After the reaction solution (mixed chloropyridine) is preheated by the preheater, it enters the light component removal tower for rectification, and the light component in the mixed chloropyridine is discharged from the first discharge port at the top of the light component removal tower, so as to realize the light component impurity removal. Then, it is not necessary to cool down, and the reaction solution after light component removal is directly transferred to the weight removal tower to separate the heavy component, and the heavy component in the mixed chloropyridine is discharged from the second discharge port at the top of the weight removal tower, so as to realize the heavy component impurity removal. By arranging the first discharge port and the second discharge port at the upper part of the light component removal tower and the weight removal tower, the reaction time and the distillation path of the reaction solution can be relatively extended, so as to ensure that the impurity separation is relatively thorough.

[0007] By optimizing the distillation equipment, this technical solution realizes that while the heavy removal distillation tower is operating, the light removal distillation tower can simultaneously carry out continuous light removal operations. Compared with the operation of a single distillation tower, the temperature must be raised for distillation, and then the temperature must be lowered and repeated. This shortens the operation time and improves efficiency to a certain extent.

[0008] Preferably, as an improvement, the lower portion of the light removal tower is connected to a light removal reboiler.

[0009] In the technical scheme, the reaction liquid in the light-removal tower can be circulated through a light-removal reboiler during the light-removal and impurity-removal treatment to ensure the light component impurity-removal effect.

[0010] Preferably, as an improvement, the lower part of the deweighting tower is connected to a deweighting reboiler.

[0011] In the technical solution, the reaction liquid in the de-heaving tower can be circulated by using a de-heaving reboiler during the de-heaving and impurity removal treatment to ensure the effect of removing impurities from the heavy components.

[0012] Preferably, as an improvement, the first discharge port is connected to a light component discharge pipe.

[0013] In the technical solution, by connecting the light component discharge pipe at the first discharge port, the unified collection of light components can be easily achieved, and the structural design is reasonable.

[0014] Preferably, as an improvement, the second discharge port is connected to a heavy component discharge pipe.

[0015] In the technical solution, by connecting the heavy component discharge pipe at the second discharge port, unified collection of the heavy components can be easily achieved, and the structural design is reasonable.

[0016] Preferably, as an improvement, the feed pipeline is connected between the lower parts of the light-removing tower and the heavy-removing tower.

[0017] In the technical solution, the reaction time of the reaction liquid can be relatively prolonged by feeding from the bottom and discharging from the top, thereby ensuring sufficient distillation.

[0018] Preferably, as an improvement, a product discharge port is provided at the bottom of the deweighting tower, the product discharge port is connected to a product discharge pipe, and a valve is provided on the product discharge pipe.

[0019] In the technical scheme, after the reaction liquid is distilled in the deweighting tower, the heavy components are distilled out from the top of the tower, and the distilled products are discharged from the outlet at the bottom of the tower and uniformly collected.

[0020] Preferably, as an improvement, it also includes an automatic control unit.

[0021] In this technical solution, by equipping with automatic control facilities, the light removal tower can continuously feed the heavy removal tower, thereby realizing continuous distillation, greatly shortening the operation time and improving the distillation efficiency.

[0022] Preferably, as an improvement, the height to volume ratio of the light-removing tower and the heavy-removing tower is 1:1.

[0023] In the present technical scheme, the height and volume of the light-removal tower and the heavy-removal tower are mainly determined by factors such as the volatility difference of the components to be separated, the required product purity, and the theoretical number of plates. In the present technical scheme, by setting the light-removal tower and the heavy-removal tower as structures of equal volume and height, standardized production and inventory management of equipment are facilitated, thereby reducing initial costs and the complexity of subsequent maintenance; and distillation towers of the same size are more flexible in factory layout and pipeline connection. If production needs change, the production line configuration can be more easily adjusted, and even the position or function of the distillation tower can be interchanged when necessary; not only that, distillation towers of the same size can share spare parts and maintenance tools, reducing the cost and complexity of spare parts inventory; in an emergency, such as a tower failure, another tower of the same size can be temporarily used for alternative operation to maintain production continuity, thereby ensuring production efficiency.

[0024] Preferably, as an improvement, the inner diameter ratio of the light component discharge pipe to the heavy component discharge pipe is 1:1.

[0025] In this technical solution, by setting the inner diameters of the light component discharge pipe and the heavy component discharge pipe to the same size, spare parts and maintenance tools can be shared, which simplifies construction drawings and on-site installation, and reduces construction difficulty and time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of a continuous distillation device for mixed chloropyridine in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following is further described in detail through specific implementations, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following implementations are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents, etc. used can all be obtained from commercial channels.

[0028] The figure marks in the drawings of the specification include: light component removal tower 1, heavy component removal tower 2, preheater 3, light component removal reboiler 4, first return pipe 5, light component discharge pipe 6, feed pipe 7, heavy component removal reboiler 8, second return pipe 9, heavy component discharge pipe 10, product discharge pipe 11.

[0029] Example 1

[0030] Embodiment 1 is basically as attached Figure 1 As shown: A mixed chloropyridine continuous distillation device comprises a light-removing tower 1 and a heavy-removing tower 2. The light-removing tower 1 is used for distilling and removing light impurities (substances with lower boiling points) in the mixed chloropyridine, and the heavy-removing tower 2 is used for distilling and removing heavy impurities (substances with higher boiling points) in the mixed chloropyridine. The height and volume ratio of the light-removing tower 1 and the heavy-removing tower 2 are both 1:1.

[0031] The lower part of the light removal tower 1 is provided with a first feed port, and the first feed port is connected to a preheater 3. The bottom of the light removal tower 1 is connected to a light removal reboiler 4, and a first return pipe 5 is connected between the other end of the light removal reboiler 4 and the bottom of the light removal tower 1. The upper part of the light removal tower 1 is provided with a first discharge port, and the first discharge port is connected to a light component discharge pipeline 6.

[0032] A second feed port is provided at the lower part of the de-weighting tower 2, and a feed pipe 7 is connected between the second feed port and the lower part of the de-weighting tower 1. A de-weighting reboiler 8 is connected at the bottom of the de-weighting tower 2, and a second return pipe 9 is connected between the other end of the de-weighting reboiler 8 and the de-weighting tower 2. A second discharge port is provided at the upper part of the de-weighting tower 2, and the second discharge port is connected to a heavy component discharge pipe 10, and the inner diameter ratio of the light component discharge pipe 6 to the heavy component discharge pipe 10 is 1:1. A product discharge port is provided at the bottom of the de-weighting tower 2, and the product discharge port is connected to a product discharge pipe 11, and a valve is provided on the product discharge pipe 11.

[0033] The specific implementation process is as follows: after the reaction liquid (mixed chloropyridine) is preheated by the preheater 3, it enters the light component removal tower 1 from the first feed port for distillation and circulates through the light component removal reboiler 4; the light components in the mixed chloropyridine are discharged from the first discharge port at the top of the light component removal tower 1 to achieve light component impurity removal.

[0034] Then, without cooling, the reaction liquid after light component removal is directly transferred to the de-weighting tower 2 through the second feed port along the feed pipe 7 to separate the heavy components. During this period, the reaction liquid is circulated through the second reboiler, and the heavy components in the mixed chloropyridine are discharged from the second discharge port at the top of the de-weighting tower 2 to achieve the removal of heavy components.

[0035] According to the technical solution, while the heavy removal distillation tower is operating, the light removal distillation tower can simultaneously carry out continuous light removal operations. Compared with the operation of a single distillation tower, the temperature must be raised for distillation, and then the temperature must be lowered and repeated. This shortens the operation time and improves efficiency to a certain extent.

[0036] Example 2

[0037] The difference between this embodiment and embodiment 1 is that: in this embodiment, a mixed chloropyridine continuous distillation device is equipped with an automatic control facility (not shown in the figure), which can realize continuous feeding of the light removal tower 1 to the heavy removal tower 2, thereby realizing continuous distillation, greatly shortening the operation time and improving the distillation efficiency.

[0038] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A mixed chloropyridine continuous distillation device, characterized in that: It comprises a light-removing tower and a heavy-removing tower. The feed end of the light-removing tower is connected with a preheater. A feed pipeline is connected between the light-removing tower and the heavy-removing tower. A first discharge port is arranged on the upper part of the light-removing tower, and a second discharge port is arranged on the upper part of the heavy-removing tower.

2. A mixed chloropyridine continuous distillation device according to claim 1, characterized in that: The lower part of the light removal tower is connected with a light removal reboiler.

3. A mixed chloropyridine continuous distillation device according to claim 2, characterized in that: The lower part of the deweighting tower is connected with a deweighting reboiler.

4. A mixed chloropyridine continuous distillation device according to claim 3, characterized in that: The first discharge port is connected to a light component discharge pipeline.

5. A mixed chloropyridine continuous distillation device according to claim 4, characterized in that: The second discharge port is connected with a heavy component discharge pipeline.

6. A mixed chloropyridine continuous distillation device according to claim 5, characterized in that: The feed pipeline is connected between the lower part of the light-removing tower and the heavy-removing tower.

7. A mixed chloropyridine continuous distillation device according to claim 6, characterized in that: A product discharge port is arranged at the bottom of the deweighting tower, and the product discharge port is connected with a product discharge pipe, and a valve is arranged on the product discharge pipe.

8. A mixed chloropyridine continuous distillation device according to claim 7, characterized in that: An automatic control unit is also included.

9. A mixed chloropyridine continuous distillation device according to claim 8, characterized in that: The height and volume ratio of the light-removing tower and the heavy-removing tower are both 1:

1.

10. A mixed chloropyridine continuous distillation device according to claim 9, characterized in that: The inner diameter ratio of the light component discharge pipe to the heavy component discharge pipe is 1:1.

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