Evaporation and filtration device for processing dimethylformamide synthesis mixture liquid

Abstract

The present invention provides an evaporation and filtration device for treating a dimethylformamide synthesis mixture liquid, which is sequentially provided with an evaporation zone, a filtration zone, and a recovery zone from top to bottom, and adjacent zones are separated by baffles; the evaporation zone has a high-temperature steam inlet and a condensate outlet, and a cleaning unit is provided at the outer top, and the cleaning unit is connected to the evaporation tube and can controllably clean the inside thereof; the filtration zone is provided with a filtration unit and a feed pipe, and the feed pipe is respectively connected to a supply device of the dimethylformamide synthesis mixture liquid and the filtration unit; the evaporation tube penetrates downward from the top of the evaporation zone through the baffle and the filtration unit, and the lower port is located in the recovery zone; a gas phase outlet is provided at the upper part of the evaporation tube, a valve is provided at the lower port, and a filtrate inlet communicating with the filtrate output of the filtration unit is provided on the lower side wall of the evaporation tube. The present invention integrates the evaporation and filtration processes in a set of devices, realizes continuous filtration and evaporation, and has a small floor area.

Description

Technical Field

[0001] The present invention relates to the technical field of dimethylformamide synthesis, and more specifically, to an evaporation and filtration device for treating a dimethylformamide synthesis mixture liquid. Background Art

[0002] Dimethylformamide, also known as N,N-dimethylformamide, abbreviated as DMF in English, is a widely used chemical raw material. Industrially, it is usually prepared by reacting dimethylamine with carbon monoxide at high temperature and high pressure in the presence of a catalyst. During this reaction process, impurities in the raw materials are prone to react with the catalyst at high temperature to produce by-products such as sodium formate and sodium carbonate. The reaction product needs to be first filtered and evaporated to remove the by-products and catalyst after the reaction, and then sent to the subsequent light-removing tower for deep separation. In the evaporation separation process, crystals are extremely likely to form and adhere to the inner wall of the device, thereby affecting the evaporation effect. Therefore, after production for a period of time, it is necessary to regularly stop the machine for cleaning and maintenance of the device, resulting in a decrease in production efficiency and an increase in production costs.

[0003] In view of the above problems, Patent CN207203493U discloses a dimethylformamide evaporation application device, which includes an evaporation separator, an evaporation circulation pump, a filter, and an evaporation heater. The bottom material outlet of the evaporation separator is connected to the input end of the evaporation circulation pump, the output end of the evaporation circulation pump is respectively connected to the input end of the filter and the input end of the evaporation heater, and the output end of the filter and the output end of the evaporation heater are respectively connected to the middle of the evaporation separator. Through this patent solution, a part of the material is pressurized by the evaporation circulation pump and then enters the filter to remove impurities such as the catalyst, and the clear liquid returns to the evaporation separator. The material in the evaporation separator is repeatedly circulated, and the circulating liquid returns to the filter to gradually remove a small amount of catalyst and other impurities that have not been filtered out. Another part of the material enters the evaporation heater through the evaporation circulation pump, is heated by steam and then returns to the evaporation separator, so that the separation of each component from the liquid phase to the gas phase is completed under a certain temperature control.

[0004] The above patent solution adopts two sets of filtration and evaporation systems and is connected in parallel. While one system is in production, the other can be cleaned and maintained. Although this solution solves the problem of maintenance without having to stop the machine, it requires an equipment cost twice that of the production capacity. Moreover, when maintaining one of the systems, it still uses the conventional cleaning and maintenance method, without realizing the function of automatic cleaning, and also fails to reduce the maintenance cost. In addition, in the above patent solution, the filtration unit and the evaporation unit are separately arranged and connected by pipelines, resulting in a large floor area of the equipment. In addition, due to the increase in the length of the pipeline, crystals are likely to form on the inner wall of the pipeline, which is not conducive to equipment maintenance.

[0005] In view of this, the present invention application is specifically proposed. Summary of the Invention

[0006] In view of the problems existing in the product evaporation process after synthesizing N,N-dimethylformamide in the prior art, the present invention provides a method for realizing automatic cleaning and maintenance of equipment under the condition of non-stop operation without affecting production capacity, and reducing the input cost of production.

[0007] To solve the above technical problems, the present invention provides an evaporation and filtration device for treating a dimethylformamide synthesis mixture liquid. The evaporation and filtration device is sequentially provided with an evaporation zone, a filtration zone, and a recovery zone from top to bottom. A first baffle is provided between the evaporation zone and the filtration zone, and a second baffle is provided between the filtration zone and the recovery zone.

[0008] The evaporation zone has a high-temperature steam inlet and a condensate outlet, and a cleaning unit is provided at the outer top. The cleaning unit is connected to the evaporation tube and can controllably clean the inside of the evaporation tube. The filtration zone is provided with a filtration unit and a feed pipe. One end of the feed pipe is connected to the supply device of the dimethylformamide synthesis mixture liquid through a pressure pump, and the other end is connected to the filtration unit.

[0009] The evaporation tube penetrates downward from the top of the evaporation zone through the first baffle, the filtration unit, and the second baffle, and the lower port is located in the recovery zone.

[0010] A gas phase outlet is provided at the upper part of the evaporation tube, a controllable opening and closing valve is provided at the lower port, and a filtrate inlet communicating with the filtrate output of the filtration unit is provided on the lower side wall of the evaporation tube.

[0011] As an example, the filtration unit includes a housing and a filter element. The space between the housing and the filter element is the liquid inlet area, and the inside of the filter element is the filtrate. The evaporation tube passes through the center of the filtrate area.

[0012] As an example, multiple groups of the above-mentioned filtration units, evaporation tubes, and cleaning units are provided. The feed pipe is connected to each filtration unit through multiple feed branch pipes respectively provided with valves.

[0013] As an example, the filtration unit further includes a scraping unit. One end of the scraping unit is connected to the housing, and the other end provided with a scraping structure is arranged on the outer periphery of the filter element for scraping the filter substances on the outer surface of the filter element.

[0014] As an example, the scraping unit is composed of a connecting block, a connecting rod, and a second scraping blade. One end of the connecting rod is connected to the housing, and the other end is connected to the connecting block. The connecting block is arranged around the outer periphery of the filter element, and the second scraping blade is arranged on the bottom surface of the connecting block close to the filter element and contacts the outer surface of the filter element.

[0015] As an example, vertical guide rails are provided on the inner wall of the housing, and the connecting rod moves up and down along the vertical guide rails, driving the second scraping blade on the connecting block to move up and down along the filter element.

[0016] As an example, a third wiper is provided at the bottom of the connecting block in a direction perpendicular to the filter element, and the third wiper forms an angle of 45° with the vertical direction.

[0017] As an example, an annular guide rail is provided on the inner wall of the housing, and the connecting rod moves along the annular guide rail, driving the third wiper provided at the lower part of the connecting block to move, and scraping the filtering foreign matters scraped off by the second wiper and falling on the bottom plate of the liquid inlet area along the bottom plate of the liquid inlet area to the filtering material discharge port and discharging them into the recovery area.

[0018] As an example, the cleaning unit includes a motor, a telescopic rod, and a cleaning mechanism. One end of the telescopic rod is connected to the motor, and the other end is connected to the cleaning mechanism that can telescopically enter and exit the evaporation tube.

[0019] As an example, the cleaning mechanism includes a first wiper and a water spray port. The telescopic rod has a hollow structure inside, and one end is connected to an external cleaning liquid storage device, and the other end is connected to the water spray port.

[0020] As an example, the gas phase outlet is connected to a gas phase collection pipe, and the gas phase collection pipe is connected to a de-light tower in the subsequent process.

[0021] The present invention has the following advantages compared with the prior art:

[0022] 1. The present invention integrates the evaporation process and the filtration process in a set of devices, realizing continuous filtration and evaporation. When the device needs to be cleaned, it can be automatically cleaned and maintained independently for a single filtration and evaporation unit without stopping the operation, improving production efficiency.

[0023] 2. The present invention not only realizes continuous production, but also reduces the floor area of the device and lowers the production input cost.

[0024] 3. The device of the present invention is suitable for flexibly designing the number of evaporation and filtration units according to the production capacity requirements. When a single evaporation and filtration unit is cleaned and maintained, the remaining evaporation and filtration units can still meet the production capacity requirements.

[0025] 4. Further, the cleaning and maintenance of the evaporation and filtration units of the present invention can be automatically carried out through a control program without manual intervention, and the cleaning control program is independent of the production control program, and the production can be carried out while the evaporation and filtration units are alternately cleaned, greatly realizing efficient production.

[0026] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will become obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained through the structures specifically pointed out in the specification, claims, and drawings. Description of the Drawings

[0027] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

[0028] Figure 1 It is a structural sectional view of the evaporation and filtration device for processing the dimethylformamide synthesis mixture liquid of the present invention.

[0029] Figure 2 is Figure 1 a schematic structural diagram of the filtration unit in

[0030] Figure 3 is Figure 2 a top view of the filtration unit of

[0031] Figure 4 is a schematic structural diagram of the cleaning unit.

[0032] Figure 5 is a schematic diagram of the state of the cleaning unit during evaporation and filtration.

[0033] Figure 6 is a schematic diagram of the state of the cleaning unit during cleaning.

[0034] Figure 7 is a schematic structural diagram of the cleaning mechanism.

[0035] Figure 8 is a schematic diagram of the state after scraping by the scraping unit during the cleaning of the filter element.

[0036] Figure 9 is a schematic structural diagram of the scraping unit.

[0037] Figure 10 is a schematic diagram for explaining the movement mode of the scraping unit.

[0038] Figure 11 is an example diagram of the automatic control mode of the evaporation and filtration device of the present invention.

[0039] Explanation of reference numerals in the drawings:

[0040] 11 Filtering and evaporation device; 12 Evaporation zone; 13 Filtration zone; 14 Recovery zone; 15 Evaporation tube; 16 Filtration unit; 17 Cleaning unit; 121 High-temperature steam inlet; 122 Condensate outlet; 123 First baffle; 131 Feed pipe; 132 Second baffle; 133 Feed branch pipe; 134 Pressure pump; 170 Gas-phase collection pipe; 151 Butterfly valve; 152 Filtrate inlet; 153 Crystallized product outlet; 161 Filter element; 162 Liquid inlet area; 163 Filtrate area; 18 Scraping unit; 19 First control valve; 151 Butterfly valve; 152 Filtrate inlet; 153 Crystallized product outlet; 181 Connecting block; 182 Connecting rod; 171 Motor; 172 Telescopic rod; 173 Cleaning mechanism; 41 Gas-phase outlet; 71 First scraping blade; 72 Water spray nozzle; 81 Second control valve; 82 Filtered material discharge outlet; 91 Second scraping blade; 92 Third scraping blade; 101 Vertical guide rail; 102 Ring guide rail Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0042] As Figure 1 shown, the filtering and evaporation device 11 is provided with an evaporation zone 12, a filtration zone 13, and a recovery zone 14 from top to bottom in sequence. A first baffle 123 is provided between the evaporation zone 12 and the filtration zone 13, and a second baffle 132 is provided between the filtration zone 13 and the recovery zone 14.

[0043] The filtering and evaporation device 11 is provided with an evaporation tube 15, a filtration unit 16, and a cleaning unit 17. The filtration unit 16 is located in the filtration zone 13 and is preferably provided at the middle position of the filtering and evaporation device 11. The evaporation tube 15 penetrates downward from the top of the evaporation zone 12 through the first baffle 123 and the second baffle 132 to the recovery zone 14. The evaporation tube 15 passes through the center of the filtration unit 16. A butterfly valve 151 is provided at the junction of the evaporation tube 15 and the bottom of the filtration unit 16 for controlling the material in the evaporation tube 15 to be discharged into the lower recovery zone 14 through the opening of the butterfly valve 151. A filtrate inlet 152 is provided on the side wall of the evaporation tube 15 near the bottom of the filtration unit 16 for the filtrate after being filtered by the filter element 161 to enter the evaporation tube 15.

[0044] The upper part of the evaporation tube 15 is also provided with a gas phase outlet 41, and the gas phase outlet 41 is connected to the gas phase collection tube 170, and the gas phase collection tube 170 is connected to the light component removal tower in the subsequent process.

[0045] The filtration area 13 is provided with a feed pipe 131. One end of the feed pipe 131 is connected to the supply device of the dimethylformamide synthesis mixture liquid through a pressure pump 134, and the other end is connected to the filtration unit 16. The cleaning unit 17 is arranged on the outer top of the evaporation area 12 and is communicated with the top end of the evaporation tube 15.

[0046] As a specific example, as Figure 2 shown, the filtration unit 16 includes a housing, a filter element 161 and a scraping unit 18. The space between the housing and the filter element 161 is the liquid inlet area 162, and the inside of the filter element 161 is the filtrate area 163.

[0047] As a specific example, a filter residue discharge port 82 is arranged at a position on the bottom plate of the liquid inlet area 162 close to the filter element 161, and preferably 2 to 4 are arranged along the circumference of the filter element 161.

[0048] Preferably, referring to Figure 8 , a second control valve 81 is arranged at the filter residue discharge port 82 for controlling the opening or closing of the filter residue discharge port 82.

[0049] One end of the scraping unit 18 is connected to the housing, and the other end with a scraping structure is arranged on the outer periphery of the filter element 161 for scraping the filter residue on the outer surface of the filter element 161 when the filtration unit 16 is maintained and cleaned.

[0050] As a specific example, as Figure 3 and Figure 9 shown, the scraping unit 18 is composed of a connecting block 181, a connecting rod 182 and a second scraping blade 91. One end of the connecting rod 182 is connected to the housing, and the other end is connected to the connecting block 181. The connecting block 181 is circular and surrounds the outer periphery of the filter element 161 for one week. The second scraping blade 91 is arranged on the circumference of the bottom surface of the connecting block 181 close to the filter element 161 side. The second scraping blade 91 is inclined towards the filter element 161 and can contact the filter element 161. Such an arrangement is beneficial for the second scraping blade 91 to scrape the filter residue on the outer surface of the filter element 161.

[0051] A plurality of second scraping blades 91 are uniformly arranged along the inner circumference of the connecting block 181 and are in contact with the outer surface of the filter element 161, which is convenient for scraping off the solid foreign matters remaining on the surface of the filter element 161.

[0052] As a way, vertical guide rails 101 are arranged on the inner wall of the housing. The connecting rod 182 moves up and down along the vertical guide rails 101, driving the circular second wiper 91 on the connecting block 181 to move up and down along the filter element 161 to scrape off solid foreign matters on the outer surface of the filter element 161.

[0053] As a way, a third wiper 92 is arranged at the bottom of the connecting block 181 in a direction perpendicular to the filter element 161, and the third wiper 92 forms an angle of 45° with the vertical direction. Preferably, multiple groups of third wipers 92 are arranged at intervals along the circumference of the bottom of the connecting block 181.

[0054] When the above-mentioned connecting rod 182 moves along the vertical guide rails 101 to the lower part of the liquid inlet area 162, the second wiper 91 completes scraping off the foreign matters on the surface of the filter element 161.

[0055] Furthermore, an annular guide rail 102 is arranged on the inner wall of the housing. The connecting rod 182 moves along the annular guide rail 102, driving the third wiper 92 arranged at the lower part of the connecting block 181 to move, and scraping the filtered foreign matters that are scraped off by the second wiper 91 and fall on the bottom plate of the liquid inlet area 162 along the bottom plate of the liquid inlet area 162 to the filter discharge outlet 82 and discharging them into the recovery area 14.

[0056] As a way, the whole of the filtration evaporation device 11 is cylindrical, including a plurality of filtration units 16 and evaporation tubes 15. Each filtration unit 16 and evaporation tube 15 correspond one by one. The filtration unit 16 and evaporation tube 15 form a set in the aforementioned manner. The feed pipe 131 is connected to each filtration unit 16 through independent feed branch pipes 133, and first control valves 19 are respectively arranged on the feed branch pipes 133 to control the input of the feed liquid into the filtration unit 16. See Figure 1-2 , the mixed feed liquid after the synthesis of N, N-dimethylformamide is input from the feed pipe 131 in the middle filtration area 13, and then controllably enters each filtration unit 16 through the feed branch pipes 133 provided with the first control valves 19 respectively.

[0057] The feed branch pipe 133 of the feed pipe 131 is connected to the liquid inlet area 162. The mixed liquid after the synthesis of N, N-dimethylformamide passes from the liquid inlet area 162 through the filter element 161 inward. After being filtered by the filter element 161, it reaches the filtrate area 163. The liquid entering the filtrate area 163 enters the evaporation tube 15 through the filtrate inlet 152 provided on the lower side wall of the evaporation tube 15.

[0058] The following combines Figure 1-3 to introduce the specific process of the mixed feed liquid to be treated for the synthesis of dimethylformamide entering the evaporation tube 15:

[0059] The dimethylformamide synthesis mixture liquid is pressurized by a pressure pump 134 and then input into a feed branch pipe 133 through a feed pipe 131. The control system opens a first control valve 19, and the mixture liquid enters an inlet liquid area 162. Then, after the mixture liquid is filtered by a filter element 161, the filtered matter adheres to the outer surface of the filter element 161, and the filtrate enters a filtrate area 163 through the filter element 161. The liquid entering the filtrate area 163 enters an evaporation pipe 15 through a filtrate inlet 152 provided on the side wall of the evaporation pipe 15 near the bottom of the filtrate area 163, and gradually rises in the evaporation pipe 15 under the continuous pressure of the pressure pump 134.

[0060] See Figure 1 、 Figure 2 、 Figure 4 After the filtrate filtered by the filter element 161 enters the evaporation pipe 15 through the filtrate inlet 152, under the action of the pressure pump 134 supplying the dimethylformamide synthesis mixture liquid, the filtrate in the evaporation pipe 15 continuously rises and reaches the evaporation pipe section in an evaporation area 12.

[0061] A high-temperature steam inlet 121 is provided in the middle part of the evaporation area 12, and a condensate outlet 122 is provided at the bottom of the evaporation area 12. High-temperature steam is introduced into the evaporation area 12 through the high-temperature steam inlet 121. The evaporation area 12 is filled with high-temperature steam to heat and evaporate the low-temperature filtrate in the evaporation pipe 15. The high-temperature steam is cooled by the low-temperature liquid in the evaporation pipe 15 and becomes condensate, and then is discharged through the condensate outlet 122.

[0062] After the low-temperature filtrate in the evaporation pipe 15 is heated by high-temperature steam, a part forms gas and is discharged from an upper gas phase outlet 41 to a gas phase collection pipe 170. The gas phase collection pipe 170 sends the collected gaseous substances to a debutanizer in the subsequent process for separation.

[0063] The liquid that first enters the evaporation pipe 15 and rises to the evaporation area 12 is partially evaporated into gas and discharged. The liquid that does not form gas continues to be in the evaporation pipe 15, mixes with the liquid that enters the evaporation pipe 15 later, and is continuously heated and evaporated by the high-temperature steam in the evaporation area 12. After repeated cycling, the liquid in the evaporation pipe 15 is continuously formed into gas phase and discharged to the downstream debutanizing process.

[0064] In the above process, by controlling the pressure of the pressure pump 134, it is ensured that the liquid level height in the evaporation pipe 15 is always lower than the height of the gas phase outlet 41 above the evaporation pipe 15. After running for a period of time, crystals will form on the inner wall of the evaporation pipe 15, affecting the subsequent evaporation process. Therefore, after the device runs for a period of time, it is necessary to use a cleaning unit 17 to clean the inner wall of the evaporation pipe 15.

[0065] As a specific example, see Figure 1 、 4-7, the cleaning unit 17 includes a motor 171, a telescopic rod 172, and a cleaning mechanism 173. One end of the telescopic rod 172 is connected to the motor 171, and the other end is connected to the cleaning mechanism 173. Among them, the cleaning mechanism 173 includes a first wiper blade 71 and a water spray nozzle 72, and the water spray nozzle 72 communicates with an external cleaning liquid storage device.

[0066] As a specific example, the cross-section of the first wiper blade 71 is circular, and the outer circumference of the circle contacts the inner wall of the evaporation tube 15 for scraping the crystals on the inner wall of the evaporation tube 15.

[0067] As an example, see Figure 7 , the water spray nozzle 72 is oval and is opened on the first wiper blade 71, preferably arranged along the circumferential direction of the first wiper blade 71, and the spray direction is inclined towards the inner wall of the evaporation tube 15.

[0068] See Figure 5 and Figure 6 , when the inner wall of the evaporation tube 15 needs to be cleaned, open the butterfly valve 151 at the bottom of the evaporation tube 15 to drain the liquid in the evaporation tube 15. The motor 171 runs to drive the telescopic rod 172 to extend, and the telescopic rod 172 pushes the cleaning mechanism 173 to move downward along the evaporation tube 15, thereby driving the first wiper blade 71 to move downward along the inner wall of the evaporation tube 15 to scrape off the crystals on the inner wall.

[0069] As a way, the telescopic rod 172 has a hollow structure inside and is connected to an external cleaning liquid storage device. The telescopic rod 172 is connected to the water spray nozzle 72, and the cleaning liquid is supplied to the cleaning mechanism 173 through the inner cavity of the telescopic rod 172 and sprayed out through the water spray nozzle 72 onto the inner wall of the evaporation tube 15 to further clean the inner wall of the evaporation tube 15.

[0070] Since multiple groups of evaporation tubes 15 and filtration units 16 are provided and are independently controlled to work with each other, during the cleaning process of the evaporation tubes 15, the work of other evaporation tubes 15 and filtration units 16 is not affected, so that the evaporation tubes 15 can be cleaned in turn while in production.

[0071] Using the water spray nozzle 72 of the above-mentioned cleaning unit 17, the reverse flushing of the filter element 161 in the filtration unit 16 can be further realized, specifically as follows:

[0072] Close the butterfly valve 151 at the lower part of the evaporation tube 15, start the water spraying function of the cleaning unit 17 at the upper part of the evaporation tube 15, and spray water into the evaporation tube 15 through the water spray nozzle 72. The water sprayed into the evaporation tube 15 reversely enters the filtrate area 163 through the filtrate inlet 152 on the side wall at the lower part of the evaporation tube 15, and reversely passes through the filter element 161 under a certain pressure of the liquid inside the evaporation tube 15 to further wash off the foreign matters on the outer surface of the filter element 161.

[0073] The liquid after flushing the filter element 161 enters the liquid inlet area 162. At this time, the second control valve 81 on the bottom plate of the liquid inlet area 162 is opened, and the mixed liquid after flushing the filter element 161 is discharged to the recovery area 14 at the lower part of the device.

[0074] The evaporation filtration device of the present invention can achieve full automation, and the operation of each process is adjusted through the control system. As an example, Figure 11 a adoptable control method is given, but it is not used to limit the protection scope. Those of ordinary skill in the art can use other control methods under the concept of the above basic device of the present invention, which also belongs to the scope of the present invention.

[0075] The control system is divided into two independent control units: production control and cleaning control.

[0076] The production control unit is mainly used to control the feeding, the pressure regulation of the pressure pump 134, and the temperature and quantity control of the high-temperature steam injection during evaporation filtration. By controlling the opening and closing of the first control valve 19, the use or deactivation of the single-group evaporation tube 15 and the filtration unit 16 is further controlled. And each first control valve 19 can be controlled independently to realize the independent use of each single-group evaporation tube 15 and filtration unit 16.

[0077] The cleaning control unit mainly controls the actions of the cleaning unit 17 and the scraping unit 18.

[0078] For the single-group evaporation tube 15 and the filtration unit 16, when the corresponding first control valve 19 is opened, the control system switches the single-group evaporation tube 15 and the filtration unit 16 to production control, and at this time, its corresponding cleaning unit 17 is controlled to close.

[0079] When the first control valve 19 corresponding to the single-group evaporation tube 15 and the filtration unit 16 is closed, the control system switches the group of evaporation tubes 15 and the filtration unit 16 to cleaning control, and at this time, the production control unit of the group of evaporation tubes 15 and the filtration unit 16 is closed. During the switching process of the above control units, the use states of other groups of evaporation tubes 15 and filtration units 16 will not be affected.

[0080] Although the disclosed embodiments of the present invention are as above, the content described is only the embodiments adopted for the convenience of understanding the present invention and is not used to limit the present invention. Any person skilled in the art within the scope of the present invention can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the patent protection scope of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. An evaporation and filtration device for processing a dimethylformamide synthesis mixture liquid, characterized in that, The evaporation and filtration device (11) is provided with an evaporation zone (12), a filtration zone (13), and a recovery zone (14) in sequence from top to bottom. A first baffle (123) is provided between the evaporation zone (12) and the filtration zone (13), and a second baffle (132) is provided between the filtration zone (13) and the recovery zone (14). The evaporation zone (12) has a high-temperature steam inlet (121) and a condensate outlet (122), and a cleaning unit (17) is provided at the outer top. The cleaning unit (17) is connected to the evaporation tube (15) and can controllably clean the inside of the evaporation tube (15). The filtration zone (13) is provided with a filtration unit (16) and a feed pipe (131). One end of the feed pipe (131) is connected to the supply device of the dimethylformamide synthesis mixture liquid through a pressure pump (134), and the other end is connected to the filtration unit (16). The evaporation tube (15) penetrates downward from the top of the evaporation zone (12) through the first baffle (123), the filtration unit (16), and the second baffle (132), and the lower port is located in the recovery zone (14). The upper part of the evaporation tube (15) is provided with a gas phase outlet (41), and the lower port is provided with a controllable opening and closing valve. The lower side wall of the evaporation tube (15) is provided with a filtrate inlet (152) communicating with the filtrate output of the filtration unit (16). The gas phase outlet (41) is connected to a gas phase collection pipe (170), and the gas phase collection pipe (170) is connected to the de-light tower of the subsequent process.

2. The evaporation and filtration device for processing the dimethylformamide synthesis mixture liquid according to claim 1, wherein The filtration unit (16) includes a housing and a filter element (161). The space between the housing and the filter element (161) is a liquid inlet zone (162), and the inside of the filter element (161) is a filtrate zone (163). The evaporation tube (15) passes through the center of the filtrate zone (163).

3. The evaporation and filtration device for treating the dimethylformamide synthesis mixture liquid according to claim 2, wherein Multiple sets of the filtration unit (16), evaporation tube (15), and cleaning unit (17) are provided. The feed pipe (131) is connected to each filtration unit (16) through a plurality of feed branch pipes (133) respectively provided with valves.

4. The evaporation and filtration device for processing the dimethylformamide synthesis mixture liquid according to claim 2, characterized in that, The filtration unit (16) further includes a scraping unit (18). One end of the scraping unit (18) is connected to the housing, and the other end provided with a scraping structure is arranged on the outer periphery of the filter element (161) for scraping the filter substances on the outer surface of the filter element (161).

5. The evaporation and filtration device for treating the dimethylformamide synthesis mixture liquid according to claim 4, wherein, The scraping unit (18) is composed of a connecting block (181), a connecting rod (182), and a second scraping blade (91). One end of the connecting rod (182) is connected to the housing, and the other end is connected to the connecting block (181). The connecting block (181) is arranged around the outer periphery of the filter element (161). The second scraping blade (91) is arranged on the bottom surface of the connecting block (181) close to one side of the filter element (161) and contacts the outer surface of the filter element (161).

6. The evaporation and filtration device for treating the dimethylformamide synthesis mixture liquid according to claim 5, characterized in that, Vertical guide rails (101) are arranged on the inner wall of the housing. The connecting rod (182) moves up and down along the vertical guide rails (101), driving the second scraping blade (91) on the connecting block (181) to move up and down along the filter element (161).

7. The evaporation and filtration device for treating the dimethylformamide synthesis mixture liquid according to claim 5, wherein A third scraping blade (92) is arranged at the bottom of the connecting block (181) in the direction perpendicular to the filter element (161), and the third scraping blade (92) forms an angle of 45° with the vertical direction.

8. The evaporation and filtration device for treating the dimethylformamide synthesis mixture liquid according to claim 7, characterized in that, An annular guide rail (102) is provided on the inner wall of the housing. The connecting rod (182) moves along the annular guide rail (102), driving the third wiper (92) provided at the lower part of the connecting block (181) to move, and scraping the filtered foreign matters that are scraped off by the second wiper (91) and fall on the bottom plate of the liquid inlet area (162) along the bottom plate of the liquid inlet area (162) to the filter discharge port (82), and discharging them into the recovery area (14).

9. The evaporation and filtration device for processing the dimethylformamide synthesis mixture liquid according to claim 1, characterized in that, The cleaning unit (17) includes a motor (171), a telescopic rod (172), and a cleaning mechanism (173). One end of the telescopic rod (172) is connected to the motor (171), and the other end is connected to the cleaning mechanism (173) that can telescopically enter and exit the evaporation tube (15). The cleaning mechanism (173) includes a first wiper (71) and a water spray port (72). The telescopic rod (172) has a hollow structure inside, and one end is connected to an external cleaning liquid storage device, and the other end is connected to the water spray port (72).

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