Trifluoroethyl hexafluoropropyl ether purification device

Abstract

The utility model discloses a trifluoroethyl hexafluoropropyl ether purification device. The trifluoroethyl hexafluoropropyl ether purification device comprises a pretreatment unit, the pretreatment unit comprises a distillation tower, a pretreatment tower kettle, a pretreatment condenser, a pretreatment reflux ratio controller, a light fraction tank, a circulating fraction tank and a middle fraction tank; a distillation return pipe and a distillation output pipe are arranged on the distillation tower; the distillation output pipe is connected with the inlet end of the pretreatment condenser, the outlet end of the pretreatment condenser is connected with the inlet end of the pretreatment reflux ratio controller, and the outlet end of the pretreatment reflux ratio controller is respectively connected with the distillation reflux pipe, the inlet end of the light fraction tank, the inlet end of the circulating fraction tank and the inlet end of the middle fraction tank; a raw material input pipe, a pretreatment heating medium inlet pipe, a pretreatment heating medium outlet pipe and a pretreatment circulating pipe are arranged on the pretreatment tower kettle, the pretreatment circulating pipe is connected with the outlet end of the circulating fraction tank, and a circulating control valve is arranged on the pretreatment circulating pipe. Therefore, the unreacted hexafluoropropylene can be recovered, the loss of raw materials is reduced, and the efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fine chemical equipment, in particular to a trifluoroethyl hexafluoropropyl ether purification device. Background Art

[0002] Trifluoroethyl hexafluoropropyl ether is a hydrofluoroether.

[0003] Hydrofluoroethers have become a new generation of ozone depleting substances (ODS) substitutes due to their zero ODP, low GWP, low viscosity, low freezing point, low surface tension, good electrochemical stability and other excellent properties. In addition, hydrofluoroethers also have the characteristics of low toxicity, non-corrosiveness, non-flammability, no smoke and dust generation, easy storage and transportation, and have unparalleled advantages over other substitutes.

[0004] Hydrofluoroethers have the characteristics of high chemical stability, high thermal stability, flame retardancy, low viscosity, etc., and are considered to be an ideal solvent or additive for battery electrolytes. The oxygen and fluorine atoms in the structure can better coordinate lithium ions, improve the solubility of hydrofluoroethers in lithium salts, and enhance the lithium ion conductivity. They can also capture hydrogen radicals generated during use, reduce the possible risk of thermal runaway, and have good compatibility with a variety of materials.

[0005] At present, the preparation of hydrofluoroethers is mostly carried out by reacting with alkali metal hydrides to obtain alcohol salts. This type of reaction has problems such as poor reaction controllability and safety, resulting in many by-products, low purity and low yield.

[0006] The crude trifluoroethyl hexafluoropropyl ether produced industrially contains unreacted hexafluoropropylene and trifluoroethanol. However, the existing production equipment cannot fully remove the unreacted hexafluoropropylene and trifluoroethanol.

[0007] Therefore, a trifluoroethyl hexafluoropropyl ether purification device is urgently needed to overcome one or more of the above-mentioned defects. Utility Model Content

[0008] The utility model aims to provide a trifluoroethyl hexafluoropropyl ether purification device, which can recover unreacted hexafluoropropylene to reduce raw material loss and improve efficiency, and on the other hand, improve and optimize the purity of the circulating fraction, greatly reducing the content of trifluoroethanol in the circulating fraction.

[0009] To achieve the above-mentioned purpose, the trifluoroethyl hexafluoropropyl ether purification device of the utility model includes a pretreatment unit, which includes a distillation tower, a pretreatment tower kettle, a pretreatment condenser, a pretreatment reflux ratio controller, a light fraction tank, a circulating fraction tank and an intermediate fraction tank. The distillation tower is located above the pretreatment tower kettle, and the distillation tower is also assembled and connected to the pretreatment tower kettle; the distillation tower is provided with a distillation reflux pipe and a distillation output pipe, the distillation output pipe is connected to the inlet end of the pretreatment condenser, the outlet end of the pretreatment condenser is connected to the inlet end of the pretreatment reflux ratio controller, and the outlet end of the pretreatment reflux ratio controller is respectively connected to the distillation reflux pipe, the inlet end of the light fraction tank, the inlet end of the circulating fraction tank and the inlet end of the intermediate fraction tank; the pretreatment tower kettle is provided with a raw material input pipe, a pretreatment heat medium inlet pipe, a pretreatment heat medium outlet pipe and a pretreatment circulation pipe, the pretreatment circulation pipe is connected to the outlet end of the circulating fraction tank, and a circulation control valve is provided on the pretreatment circulation pipe.

[0010] Compared with the prior art, since the pretreatment unit includes a distillation tower, a pretreatment tower kettle, a pretreatment condenser, a pretreatment reflux ratio controller, a light fraction tank, a circulating fraction tank and an intermediate fraction tank, after the trifluoroethyl hexafluoropropyl ether raw material enters the pretreatment tower kettle from the raw material input pipe, all the hexafluoropropylene and a small amount of trifluoroethyl hexafluoropropyl ether in the pretreatment tower kettle are evaporated by the distillation tower at a certain temperature, and enter the light fraction tank from the top of the distillation tower through the pretreatment condenser for recycling, thereby improving efficiency and reducing raw material loss. At the same time, the circulating fraction tank can return the higher raw material component materials in the early or late stages of the cycle to the pretreatment tower kettle, avoiding repeated circulation of low-component materials and wasting energy; furthermore, the purity of the circulating fraction is improved and optimized, and the content of trifluoroethanol in the circulating fraction is greatly reduced.

[0011] Preferably, the trifluoroethyl hexafluoropropyl ether purification device of the utility model also includes a solid alkali dehydration unit, which includes a solid alkali alcohol removal and water removal device and a delivery pump, the outlet end of the intermediate distillate tank is connected to the inlet end of the solid alkali alcohol removal and water removal device through a first connecting pipe, and the outlet end of the solid alkali alcohol removal and water removal device is connected to the inlet end of the delivery pump through a second connecting pipe.

[0012] Preferably, the first connecting pipe is provided with a first control valve, and the second connecting pipe is provided with a second control valve; the solid alkali dehydration units are multiple groups arranged in parallel and capable of switchable operation.

[0013] Preferably, the trifluoroethyl hexafluoropropyl ether purification device of the utility model also includes a distillation purification unit, which includes a distillation tower and a purification tower kettle, the purification tower kettle is located below the distillation tower, and the purification tower kettle is also assembled and connected to the distillation tower, and the outlet end of the delivery pump is connected to the purification tower kettle through a third connecting pipe.

[0014] Preferably, the distillation purification unit further comprises a distillation condenser, a distillation reflux ratio controller, a semi-finished product tank and a finished product tank, the distillation tower is provided with a distillation reflux pipe and a distillation output pipe, the distillation output pipe is connected to the inlet end of the distillation condenser, the outlet end of the distillation condenser is connected to the inlet end of the distillation reflux ratio controller, the outlet end of the distillation reflux ratio controller is respectively connected to the distillation reflux pipe, the inlet end of the finished product tank and the inlet end of the semi-finished product tank, the purification tower kettle is provided with a purification heat medium inlet pipe, a purification heat medium outlet pipe and a purification circulation pipe, the purification circulation pipe is connected to the outlet end of the semi-finished product tank, and the purification circulation pipe is provided with a purification control valve.

[0015] Preferably, the first connecting pipe is connected to a fourth connecting pipe at a position between the first control valve and the solid alkali alcohol removal and water removal device, the ends of the fourth connecting pipe and the third connecting pipe merge into a confluence pipe, the confluence pipe is connected to the purification tower bottom, and the third connecting pipe is provided with a third control valve, the fourth connecting pipe is provided with a fourth control valve, and the confluence pipe is provided with a confluence control valve.

[0016] Preferably, the trifluoroethyl hexafluoropropyl ether purification device of the utility model further comprises a vacuum pipeline, and the vacuum pipeline is respectively connected to the pretreatment tower kettle, the inlet end of the pretreatment condenser and the inlet end of the distillation condenser.

[0017] Preferably, the vacuum pipeline includes a main pipeline and a first branch pipeline and a second branch pipeline branching from the main pipeline, the end of the first branch pipeline is connected to the pretreatment tower kettle, the end of the second branch pipeline is connected to the inlet end of the pretreatment condenser, the end of the main pipeline is connected to the inlet end of the distillation condenser, the first branch pipe and the second branch pipe are each provided with a branch control valve, the main pipeline is provided with a first main control valve and a second main control valve spaced a certain distance from each other, the first branch pipe and the second branch pipe are located between the first main control valve and the second main control valve, the first branch pipe is also connected to a nitrogen delivery pipe, and the nitrogen delivery pipe is provided with a nitrogen control valve.

[0018] Preferably, the number of trays of the distillation tower is 60-120, the distillation tower is a packed distillation tower, and the purification tower kettle is a packed tower kettle.

[0019] Preferably, the number of circulating distillation tanks is multiple, the number of trays of the distillation tower is 10-30, and the pretreatment condenser is a low-temperature condenser. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a plan view of one embodiment of the trifluoroethyl hexafluoropropyl ether purification device of the utility model.

[0021] Figure 2 yes Figure 1 The shown plan view of the trifluoroethyl hexafluoropropyl ether purification unit after hiding the solid alkali dehydration unit and the distillation purification unit.

[0022] Figure 3 yes Figure 1 The plan view of the solid alkali dehydration unit and the distillation purification unit in the trifluoroethyl hexafluoropropyl ether purification device is shown. DETAILED DESCRIPTION

[0023] In order to explain the technical content and structural features of the present invention in detail, further description will be given below in combination with the embodiments and the accompanying drawings.

[0024] See also Figure 1 As an example, the trifluoroethyl hexafluoropropyl ether purification device 100 of the utility model is suitable for intermittent purification of trifluoroethyl hexafluoropropyl ether, the purity of the trifluoroethyl hexafluoropropyl ether raw material is 80%-90%, which contains about 5% hexafluoropropylene and 5%-10% trifluoroethanol.

[0025] Recombination Figure 2 The trifluoroethyl hexafluoropropyl ether purification device 100 of the utility model includes a pretreatment unit 10, a solid alkali dehydration unit 20 and a distillation purification unit 30.

[0026] The pretreatment unit 10 includes a distillation tower 11, a pretreatment tower kettle 12, a pretreatment condenser 13, a pretreatment reflux ratio controller 14, a light fraction tank 15, a circulating fraction tank 16 and an intermediate fraction tank 17. The distillation tower 11 is located above the pretreatment tower kettle 12, and the distillation tower 11 is also assembled and connected to the pretreatment tower kettle 12, and the pretreatment tower kettle 12 provides support for the distillation tower 11. Optionally, as an example, the bottom of the distillation tower 11 is connected to the top of the pretreatment tower kettle 12 through a flange assembly to facilitate the assembly operation between the distillation tower 11 and the pretreatment tower kettle 12; obviously, according to actual needs, the assembly connection method between the distillation tower 11 and the pretreatment tower kettle 12 can also be other; in addition, the circulating distillation tank 16 can be selected to be multiple, such as 2 or more, so as to more effectively return the higher raw material component materials in the early or late stage of the cycle to the pretreatment tower kettle 12, more effectively improve the efficiency, avoid repeated circulation of low-component materials, and waste energy; in addition, the number of trays of the distillation tower 11 is 10-30, such as 10, 20 or 30, and the pretreatment condenser 13 is a low-temperature condenser to effectively improve the quality of distillation.

[0027] At the same time, the distillation tower 11 is provided with a distillation reflux pipe 111 and a distillation output pipe 112, and the distillation output pipe 112 is connected to the inlet end 131 of the pretreatment condenser 13; the outlet end 131 of the pretreatment condenser 13 is connected to the inlet end 141 of the pretreatment reflux ratio controller 14, and the outlet end 142 of the pretreatment reflux ratio controller 14 is respectively connected to the distillation reflux pipe 111, the inlet end 151 of the light fraction tank 15, the inlet end 161 of the circulating fraction tank 16 and the inlet end 171 of the intermediate fraction tank 17, so as to meet the condensation of the distillate by the pretreatment condenser 13. The trifluoroethyl hexafluoropropyl ether needs to enter the circulating distillation tank 16 or the intermediate distillation tank 17 according to the purity, and all the hexafluoropropylene and a small amount of trifluoroethyl hexafluoropropyl ether condensed and distilled by the pretreatment condenser 13 need to enter the light fraction tank 15; the pretreatment tower kettle 12 is provided with a raw material input pipe 121, a pretreatment heat medium inlet pipe 122, a pretreatment heat medium outlet pipe 123 and a pretreatment circulation pipe 124, the pretreatment circulation pipe 124 is connected to the outlet end 162 of the circulating distillation tank 16, and the pretreatment circulation pipe 124 is provided with a circulation control valve 125. Therefore, with the help of the coordination of the pretreatment heat medium inlet pipe 122 and the pretreatment heat medium outlet pipe 123, it is ensured that the pretreatment tower bottom 12 is at the required working temperature; with the help of the pretreatment circulation pipe 124 and the circulation control valve 125, the trifluoroethyl hexafluoropropyl ether entering the circulation distillation tank 16 can be circulated and distilled until the purity of the trifluoroethyl hexafluoropropyl ether reaches a first preset value (for example but not limited to 98%), and the trifluoroethyl hexafluoropropyl ether with a purity reaching the first preset value is distilled into the intermediate distillation tank 17.

[0028] Furthermore, combined Figure 3 The solid alkali dehydration unit 20 includes a solid alkali alcohol removal and water removal device 21 and a delivery pump 22. The outlet end 172 of the middle distillate tank 17 is connected to the inlet end 211 of the solid alkali alcohol removal and water removal device 21 through the first connecting pipe 23 to meet the need of the trifluoroethyl hexafluoropropyl ether in the middle distillate tank 17 entering the solid alkali alcohol removal and water removal device 21 for alcohol removal and water removal treatment; the outlet end 212 of the solid alkali alcohol removal and water removal device 21 is connected to the inlet end 221 of the delivery pump 22 through the second connecting pipe 24, and the outlet end 222 of the delivery pump 22 is connected to the purification tower kettle 32 described below through the third connecting pipe 25 to meet the need of the delivery pump 22 to deliver the trifluoroethyl hexafluoropropyl ether after alcohol removal and water removal into the purification tower kettle 32; optionally, as an example, the solid alkali dehydration unit 20 is a plurality of groups that are arranged in parallel and can be switched, such as but not limited to 3 groups, so that the alcohol removal and water removal operation is flexible; obviously, according to actual needs, the solid alkali dehydration unit 20 can also be one group or two groups.

[0029] The distillation and purification unit 30 includes a distillation tower 31 and a purification tower kettle 32. The purification tower kettle 32 is located below the distillation tower 31. The purification tower kettle 32 is also assembled and connected with the distillation tower 31 to meet the need of the distillation tower 31 to distill the trifluoroethyl hexafluoropropyl ether entering the purification tower kettle 32. Optionally, as an example, the bottom of the distillation tower 31 is assembled and connected with the top of the purification tower kettle 32 through a flange assembly to facilitate the assembly operation between the distillation tower 31 and the purification tower kettle 32; obviously, according to actual needs, the assembly connection method between the distillation tower 31 and the purification tower kettle 32 can also be other. More specifically, as follows:

[0030] like Figure 1 and Figure 3As shown, as an example, the first connecting pipe 23 is provided with a first control valve 232, the second connecting pipe 24 is provided with a second control valve 241, and the third connecting pipe 25 is provided with a third control valve 251. In addition, the first connecting pipe 23 is connected to the fourth connecting pipe 26 at a position between the first control valve 232 and the solid alkali de-alcoholization and de-watering device 21, and the fourth connecting pipe 26 is provided with a fourth control valve 261, and the ends of the fourth connecting pipe 26 and the third connecting pipe 25 merge into a confluence pipe 27, and the confluence pipe 27 is connected to the purification tower kettle 32; therefore, under the cooperation of the first control valve 231, the second control valve 241, the third control valve 251, the fourth control valve 261 and the confluence control valve 271, and under the operation of the delivery pump 22, the trifluoroethyl hexafluoropropyl ether from the intermediate distillate tank 17 is subjected to a cyclic de-alcoholization and de-watering treatment, so that the purity of the trifluoroethyl hexafluoropropyl ether reaches a second preset value (for example but not limited to 99%). When the purity of trifluoroethyl hexafluoropropyl ether reaches a second preset value, the trifluoroethyl hexafluoropropyl ether is transported by the transport pump 22 into the purification tower bottom 32 for distillation operation. It should be noted that in the cyclic alcohol removal and water removal operation, the first control valve 231 and the confluence control valve 271 are in a closed state, and the second control valve 241, the third control valve 251 and the fourth control valve 261 are in an open state to prevent the trifluoroethyl hexafluoropropyl ether in the intermediate distillate tank 17 from entering the solid alkali alcohol removal and water removal device 21, and the trifluoroethyl hexafluoropropyl ether entering the solid alkali alcohol removal and water removal device 21 from being sent into the purification tower kettle 32 by the delivery pump 22, thereby ensuring the reliability of the cyclic alcohol removal and water removal operation; and in the process of the delivery pump 22 sending the trifluoroethyl hexafluoropropyl ether with a purity reaching the second preset value into the purification tower kettle 32, the first control valve 231 and the fourth control valve 261 are in a closed state, and the second control valve 241, the third control valve 251 and the confluence control valve 271 are in an open state. In addition, in the process of trifluoroethyl hexafluoropropyl ether at the intermediate distillate tank 17 entering the solid alkali dealcoholization and dewatering device 21, the first control valve 231 is in an open state, the confluence control valve 271 is in a closed state, the second control valve 241, the third control valve 251 and the fourth control valve 261 can be in an open state when the delivery pump 22 is not working, and at least one of the second control valve 241, the third control valve 251 and the fourth control valve 261 needs to be in a closed state when the delivery pump 22 is in operation.

[0031] like Figure 1 and Figure 3As shown, as an example, the distillation purification unit 30 further includes a distillation condenser 33, a distillation reflux ratio controller 34, a semi-finished product tank 35 and a finished product tank 36. The distillation tower 31 is provided with a distillation reflux pipe 311 and a distillation output pipe 312, the distillation output pipe 312 is connected to the inlet end 331 of the distillation condenser 33, the outlet end 332 of the distillation condenser 33 is connected to the inlet end 341 of the distillation reflux ratio controller 34, and the outlet end 342 of the distillation reflux ratio controller 34 is respectively connected to the distillation reflux pipe 311, the inlet end 361 of the finished product tank 36 and the inlet end 351 of the semi-finished product tank 35, so as to meet the requirements of the distillation reflux ratio controller 34 for the trifluoroethyl hexafluoropropyl ether condensed by the distillation condenser 33. The purification tower kettle 32 is provided with a purification heat medium inlet pipe 321, a purification heat medium outlet pipe 322 and a purification circulation pipe 323, the purification circulation pipe 323 is connected to the outlet end 352 of the semi-finished product tank 35, and a purification control valve 324 is provided on the purification tower kettle 32. Therefore, by means of the cooperation of the purification heat medium inlet pipe 321 and the purification heat medium outlet pipe 322, it is ensured that the purification tower kettle 32 is at the required working temperature; by means of the purification circulation pipe 323 and the purification control valve 324, the trifluoroethyl hexafluoropropyl ether entering the semi-finished product tank 35 can be circulated and distilled until the purity of the trifluoroethyl hexafluoropropyl ether reaches the fourth preset value. Specifically, as an example, the number of trays of the distillation tower 31 is 60-120, such as 60, 70, 80, 90, 100, 110 or 120, so that the semi-finished product is circulated and distilled to achieve the best quality of the finished product; in addition, the distillation tower 31 can be a packed distillation tower, and the purification tower kettle 32 can be a packed tower kettle.

[0032] like Figure 1 and Figure 2 As shown, the trifluoroethyl hexafluoropropyl ether purification device 100 of the present invention further includes a vacuum pipe 40, which is respectively connected to the pretreatment tower kettle 12, the inlet end 131 of the pretreatment condenser 13 and the inlet end 331 of the distillation condenser 33; before the trifluoroethyl hexafluoropropyl ether purification device 100 of the present invention is operated, the air in the trifluoroethyl hexafluoropropyl ether purification device 100 of the present invention can be evacuated. Specifically, at Figure 1 and Figure 2As an example, the vacuum pipeline 40 includes a main pipeline 41 and a first branch pipeline 42 and a second branch pipeline 43 branching from the main pipeline 41; the end of the first branch pipeline 42 is connected to the pretreatment tower kettle 12, the end of the second branch pipeline 43 is connected to the inlet end 131 of the pretreatment condenser 13, and the end of the main pipeline 41 is connected to the inlet end 341 of the distillation condenser 34; the first branch pipe 42 and the second branch pipe 43 are each provided with a branch control valve 44, and the main pipeline 41 is provided with a first main control valve 45 and a second main control valve 46 spaced a certain distance from each other. The first branch pipe 42 and the second branch pipe 43 are located between the first main control valve 45 and the second main control valve 46. The first branch pipe 42 is also connected to a nitrogen delivery pipe 47, and the nitrogen delivery pipe 47 is provided with a nitrogen control valve 48; after the air in the trifluoroethyl hexafluoropropyl ether purification device 100 of the utility model is extracted and the first main control valve 45 is closed, high-purity nitrogen can be input into the trifluoroethyl hexafluoropropyl ether purification device 100 of the utility model through the nitrogen delivery pipe 47, so as to realize the ventilation operation of the trifluoroethyl hexafluoropropyl ether purification device 100 of the utility model. It should be noted that in the ventilation operation, the nitrogen control valve 48, the branch control valve 44 and the second main control valve 46 are in an open state.

[0033] In conjunction with the accompanying drawings, the working principle of the trifluoroethyl hexafluoropropyl ether purification device 100 of the present invention is described:

[0034] The trifluoroethyl hexafluoropropyl ether raw material enters the pretreatment tower kettle 12 from the raw material input pipe 121. At a certain temperature, all the hexafluoropropylene and a small amount of trifluoroethyl hexafluoropropyl ether in the trifluoroethyl hexafluoropropyl ether raw material are evaporated and enter the light fraction tank 15 from the top of the distillation tower 11 through the pretreatment condenser 13 for recovery and reuse.

[0035] The trifluoroethyl hexafluoropropyl ether raw material is subjected to circulating distillation under the control of the circulating control valve 125 to improve the purity of the trifluoroethyl hexafluoropropyl ether; when the purity of the trifluoroethyl hexafluoropropyl ether reaches 98%, it enters the intermediate distillate tank 17.

[0036] The trifluoroethyl hexafluoropropyl ether fraction with a purity of 98% enters the solid alkali alcohol and water removal device 21 for cyclic alcohol and water removal operations; when the purity of trifluoroethyl hexafluoropropyl ether reaches 99%, it enters the purification tower kettle 32 for distillation operations.

[0037] The trifluoroethyl hexafluoropropyl ether fraction with a purity of 99% is distilled in the distillation tower 31, so that the purity of the trifluoroethyl hexafluoropropyl ether is further improved. When the purity of the trifluoroethyl hexafluoropropyl ether reaches 99.5%, it enters the semi-finished product tank 35; when the purity of the trifluoroethyl hexafluoropropyl ether reaches 99.9%, it enters the finished product tank 36.

[0038] Compared with the prior art, since the pretreatment unit 10 includes a distillation tower 11, a pretreatment tower reactor 12, a pretreatment condenser 13, a pretreatment reflux ratio controller 14, a light fraction tank 15, a circulating fraction tank 16 and an intermediate fraction tank 17, after the trifluoroethyl hexafluoropropyl ether raw material enters the pretreatment tower reactor 12 from the raw material input pipe 121, all the hexafluoropropylene and a small amount of trifluoroethyl hexafluoropropyl ether in the pretreatment tower reactor 12 are evaporated by the distillation tower 11 at a certain temperature, and enter the light fraction tank 15 from the top of the distillation tower 11 through the pretreatment condenser 13 for recycling and reuse, thereby improving efficiency and reducing raw material loss. At the same time, the circulating fraction tank 16 can return the higher raw material component materials in the early or late stages of the cycle to the pretreatment tower reactor 12, avoiding repeated circulation of low-component materials and wasting energy; furthermore, the purity of the circulating fraction is improved and optimized, and the content of trifluoroethanol in the circulating fraction is greatly reduced.

[0039] It is worth noting that although Figure 1 The utility model shows that the trifluoroethyl hexafluoropropyl ether purification device 100 includes a pretreatment unit 10, a solid alkali dehydration unit 20 and a distillation purification unit 30; obviously, in other embodiments, one or both of the solid alkali dehydration unit 20 and the distillation purification unit 30 can be deleted, so it is not used as Figure 1 Limits shown.

[0040] It should be noted that, since the trifluoroethyl hexafluoropropyl ether purification device 100 of the utility model is applied to intermittent purification of trifluoroethyl hexafluoropropyl ether, the materials of each unit thereof are well known to those skilled in the art according to actual needs, so they are not described in detail here. In addition, an external discharge pipe 325 is connected to the bottom of the purification tower kettle 32, and an external discharge control valve 328 is provided on the external discharge pipe 325 to discharge the trifluoroethyl hexafluoropropyl ether remaining in the purification tower kettle 32 during maintenance.

[0041] In addition, in order to allow the trifluoroethyl hexafluoropropyl ether condensed by the pretreatment condenser 13 to enter the intermediate distillate tank 17 and the circulating distillate tank 16 according to the purity, and all the hexafluoropropylene and a small amount of trifluoroethyl hexafluoropropyl ether condensed by the pretreatment condenser 13 to enter the light distillate tank 15, a light distillation control valve 152 is provided between the outlet end 142 of the pretreatment reflux ratio controller 14 and the light distillate tank 15, a circulating distillation control valve 163 is provided between the outlet end 142 of the pretreatment reflux ratio controller 14 and the circulating distillation tank 16, and an intermediate distillation control valve 173 is provided between the outlet end 142 of the pretreatment reflux ratio controller 14 and the intermediate distillate tank 17. Similarly, in order to allow the trifluoroethyl hexafluoropropyl ether condensed by the distillation condenser 13 to enter the semi-finished product tank 35 and the finished product tank 36 according to the purity, a semi-finished product control valve 353 is provided between the outlet end 342 of the distillation reflux ratio controller 34 and the semi-finished product tank 35, and a finished product control valve 362 is provided between the outlet end 342 of the distillation reflux ratio controller 34 and the finished product tank 36. Finally, Figure 1 The direction indicated by the arrow A is from bottom to top.

[0042] The above disclosure is only a preferred example of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are all within the scope of the present invention.

Claims

1. A trifluoroethyl hexafluoropropyl ether purification device, comprising a pretreatment unit, characterized in that: The pretreatment unit comprises a distillation tower, a pretreatment tower kettle, a pretreatment condenser, a pretreatment reflux ratio controller, a light fraction tank, a circulating distillate tank and an intermediate distillate tank. The distillation tower is located above the pretreatment tower kettle, and the distillation tower is also assembled and connected to the pretreatment tower kettle. The distillation tower is provided with a distillation reflux pipe and a distillation output pipe. The distillation output pipe is connected to the inlet end of the pretreatment condenser, and the outlet end of the pretreatment condenser is connected to the inlet end of the pretreatment reflux ratio controller. The outlet end of the pretreatment reflux ratio controller is respectively connected to the distillation reflux pipe, the inlet end of the light fraction tank, the inlet end of the circulating distillate tank and the inlet end of the intermediate distillate tank. The pretreatment tower kettle is provided with a raw material input pipe, a pretreatment heat medium inlet pipe, a pretreatment heat medium outlet pipe and a pretreatment circulation pipe. The pretreatment circulation pipe is connected to the outlet end of the circulating distillate tank, and a circulation control valve is provided on the pretreatment circulation pipe.

2. The trifluoroethyl hexafluoropropyl ether purification device according to claim 1, characterized in that: It also includes a solid alkali dehydration unit, which includes a solid alkali alcohol removal and water removal device and a delivery pump. The outlet end of the intermediate distillate tank is connected to the inlet end of the solid alkali alcohol removal and water removal device through a first connecting pipe, and the outlet end of the solid alkali alcohol removal and water removal device is connected to the inlet end of the delivery pump through a second connecting pipe.

3. The trifluoroethyl hexafluoropropyl ether purification device according to claim 2, characterized in that: The first connecting pipe is provided with a first control valve, and the second connecting pipe is provided with a second control valve; the solid alkali dehydration units are multiple groups that are arranged in parallel and can be switched for operation.

4. The trifluoroethyl hexafluoropropyl ether purification device according to claim 3, characterized in that: It also includes a distillation and purification unit, which includes a distillation tower and a purification tower kettle. The purification tower kettle is located below the distillation tower and is also assembled and connected to the distillation tower. The outlet end of the delivery pump is connected to the purification tower kettle through a third connecting pipe.

5. The trifluoroethyl hexafluoropropyl ether purification device according to claim 4, characterized in that: The distillation purification unit also includes a distillation condenser, a distillation reflux ratio controller, a semi-finished product tank and a finished product tank. The distillation tower is provided with a distillation reflux pipe and a distillation output pipe. The distillation output pipe is connected to the inlet end of the distillation condenser, and the outlet end of the distillation condenser is connected to the inlet end of the distillation reflux ratio controller. The outlet end of the distillation reflux ratio controller is respectively connected to the distillation reflux pipe, the inlet end of the finished product tank and the inlet end of the semi-finished product tank. The purification tower kettle is provided with a purification heat medium inlet pipe, a purification heat medium outlet pipe and a purification circulation pipe. The purification circulation pipe is connected to the outlet end of the semi-finished product tank, and a purification control valve is provided on the purification circulation pipe.

6. The trifluoroethyl hexafluoropropyl ether purification device according to claim 5, characterized in that: The first connecting pipe is connected to a fourth connecting pipe at a position between the first control valve and the intermediate distillate tank. The ends of the fourth connecting pipe and the third connecting pipe merge into a merging pipe, which is connected to the purification tower kettle. The third connecting pipe is provided with a third control valve, the fourth connecting pipe is provided with a fourth control valve, and the merging pipe is provided with a merging control valve.

7. The trifluoroethyl hexafluoropropyl ether purification device according to claim 5, characterized in that: It also includes a vacuum pipeline, which is respectively connected to the pretreatment tower kettle, the inlet end of the pretreatment condenser and the inlet end of the rectification condenser.

8. The trifluoroethyl hexafluoropropyl ether purification device according to claim 7, characterized in that: The vacuum pipeline includes a main pipeline and a first branch pipeline and a second branch pipeline branching from the main pipeline, the end of the first branch pipeline is connected to the pretreatment tower kettle, the end of the second branch pipeline is connected to the inlet end of the pretreatment condenser, and the end of the main pipeline is connected to the inlet end of the distillation condenser. The first branch pipe and the second branch pipe are each provided with a branch control valve, and the main pipeline is provided with a first main control valve and a second main control valve spaced a certain distance from each other. The first branch pipe and the second branch pipe are located between the first main control valve and the second main control valve. The first branch pipe is also connected to a nitrogen delivery pipe, and the nitrogen delivery pipe is provided with a nitrogen control valve.

9. The trifluoroethyl hexafluoropropyl ether purification device according to claim 4, characterized in that: The number of trays of the distillation tower is 60-120, the distillation tower is a packed distillation tower, and the purification tower kettle is a packed tower kettle.

10. The trifluoroethyl hexafluoropropyl ether purification device according to claim 1, characterized in that: The number of the circulating fraction tanks is multiple, the number of trays of the distillation tower is 10-30, and the pretreatment condenser is a low-temperature condenser.

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