Coagulation device suitable for fluoroether carboxylic acid emulsion and coagulation method thereof
By using a closed coagulation tank, agitator, and nitrogen purging device in the coagulation process of fluoroether carboxylic acid emulsions, combined with automated foam detection and strong acid additives, the problems of residual fluoroether carboxylic acid emulsifiers and foaming were solved, achieving efficient solid-liquid separation and automated operation.
Patent Information
- Application Number
- CN202511948514.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-03-06
AI Technical Summary
In the existing technology, fluoroether emulsifiers are prone to residue and foaming during the coagulation process, resulting in excessively high polymer solid content in the coagulated liquid, and there is a lack of effective treatment methods and devices.
A closed coagulation tank equipped with a coagulant agitator and nitrogen purging device, combined with a capacitive foam level sensor and PLC controller, is used to achieve automated foam detection and purging. With the use of strong acid succinic acid as a coagulation aid and alkaline plasticizing aid, solid-liquid separation is achieved through high-shear stirring.
It effectively reduces or eliminates the solid content in coagulated materials, eliminates the foaming phenomenon of fluoroether emulsifiers, improves purging efficiency, and enables automated operation.
Smart Images
Figure CN121607117A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer preparation technology, and in particular to a coagulation device and coagulation method suitable for fluoroether carboxylic acid emulsions. Background Technology
[0002] With the ban and restriction of perfluoroalkyl and polyfluoroalkyl compounds, emulsifiers for dispersion polymerization are undergoing a generational shift, with various environmentally friendly emulsifiers being used as alternatives. Currently, fluoroether acids are commonly used as emulsifier substitutes in existing technologies. However, fluoroether acid emulsifiers are prone to residue and foaming during the coagulation process, which increases the difficulty of coagulating fluoroether acids and results in a high solid content in the coagulated liquid. The technical problem of excessively high polymer solid content in the coagulated liquid due to residual fluoroether acid emulsifiers in the emulsion remains unresolved, and there are no better methods or devices in the existing technology for effectively treating the residual liquid during the coagulation of fluoroether acids. Summary of the Invention
[0003] This invention provides a coagulation device and method suitable for fluoroether carboxylic acid emulsions, which not only ensures the reduction or even elimination of solid content in the coagulated product, but also effectively eliminates the foaming phenomenon of fluoroether carboxylic acid emulsifiers.
[0004] The present invention adopts the following technical solution: a coagulation device suitable for fluoroether carboxylic acid emulsions, comprising a closed coagulation tank, a raw material inlet at the top of the closed coagulation tank, and a coagulant agitator installed at the center of the closed coagulation tank. The coagulant agitator includes, from top to bottom, a drive motor, a drive shaft, and a stirring blade. The drive motor is installed outside the closed coagulation tank, and the output end of the drive motor is connected to the stirring blade at the bottom through the drive shaft inserted into the closed coagulation tank. The control end of the drive motor is connected to a controller, which can set the running time of the drive motor to control the start and stop of the stirring operation of the stirring blade. A foam level sensor is installed on the upper inner wall of the closed coagulation tank, and a nitrogen purging device is installed at the top of the closed coagulation tank, corresponding to the inside of the closed coagulation tank. The signal output end of the foam level sensor is connected to the signal input port of the controller, and the control port of the controller is connected to the nitrogen output control unit.
[0005] Furthermore, the nitrogen purging device of the present invention includes a high-pressure nitrogen tank. The outlet of the high-pressure nitrogen tank is connected to a plurality of high-pressure nozzles distributed on the top of a sealed condensation tank via a pipeline. The plurality of high-pressure nozzles point towards the inside of the sealed condensation tank. The nitrogen output control unit is configured as a switching solenoid valve. The switching solenoid valve is located on the pipeline and its control terminal is connected to the control port of the controller. When the foam level sensor detects that a large amount of foam has formed on the liquid surface in the sealed condensation tank, the foam level sensor transmits the foam signal to the controller. The controller issues a command to the switching solenoid valve. After the switching solenoid valve opens, the nitrogen from the high-pressure nitrogen tank is input into the high-pressure nozzles and sprayed into the sealed condensation tank through the high-pressure nozzles. Thus, the sprayed nitrogen flow disperses the foam layer on the liquid surface in the sealed condensation tank. After the foam layer is dispersed, the foam level sensor detects that the foam layer has dissipated and sends a signal to the switching solenoid valve. After the switching solenoid valve closes, the nitrogen injection stops.
[0006] Furthermore, the controller of this invention is configured as a PLC controller.
[0007] Furthermore, the foam level sensor of the present invention is configured as a capacitive foam sensor.
[0008] This invention also provides a coagulation method suitable for fluoroether carboxylic acid emulsions, which includes the following steps: Step 1, Prepare raw materials: Based on the amount of polytetrafluoroethylene emulsion with a solid content of 12.5%, by weight, when the polytetrafluoroethylene emulsion is 1000 parts, succinic acid is 0.5 parts and sodium hydroxide is 1 part. Step 2: PEP (polytetrafluoroethylene) emulsion is discharged into a closed coagulation tank, and then the coagulation aid succinic acid is added to the closed coagulation tank and mixed with the PEP emulsion. Step 3: Start the coagulant agitator and increase the agitation speed. Perform the first high-shear agitation on the mixture of polytetrafluoroethylene emulsion and succinic acid within the first agitation time set by the controller. After the set running time is up, stop the coagulant agitator. At this time, solid powder appears on the surface of the mixture in the sealed coagulation tank after agitation. Then, pour the prepared plasticizer sodium hydroxide solution into the sealed coagulation tank, which generates a large number of bubbles on the surface of the liquid, thus forming a foam layer on the surface of the liquid. Step 4: When the foam level sensor detects the foam layer formed on the liquid surface in the sealed condensation tank, the foam level sensor sends a signal to the controller. The controller controls the switch solenoid valve to open, and the nitrogen from the high-pressure nitrogen tank is sprayed into the sealed condensation tank through the high-pressure nozzle to purge the foam layer on the liquid surface. When the foam layer dissipates, the foam level sensor controls the switch solenoid valve to close through the controller, stopping the nitrogen spraying. Step 5: Start the coagulant agitator for a second high-shear agitation. Stir the sealed coagulation tank for the second time during the second running time set by the controller. After the set running time is up, stop the coagulant agitator. At this time, the mixture after stirring achieves solid-liquid separation and coagulation is completed. Then, wash the coagulated material with water and discharge it. Measure the residual liquid conductivity in the discharged coagulated material to be ≤10μs / cm.
[0009] Furthermore, the sodium hydroxide solution of the present invention has a mass percentage concentration of 10%.
[0010] Furthermore, the stirring speed of the first and second high-shear stirring of the coagulant agitator of the present invention is 300 rpm.
[0011] Furthermore, the succinic acid concentration of the present invention is 5%-10% by mass.
[0012] The present invention has the following beneficial effects: The method and apparatus of the present invention can achieve the following during coagulation: succinic acid, a strong acid, is added as a coagulation aid at the initial stage of coagulation, thereby rendering the residual emulsifier ineffective; succinic acid can capture the ammonium ions of ammonium fluoroether carboxylate, which is a weak acid ammonium salt, reducing the water-soluble ammonium salt to an insoluble acid, thus destroying its emulsifier function and facilitating the complete precipitation of polymeric substances; when solids precipitate, sodium hydroxide solution is added as a plasticizing aid. Sodium hydroxide can impart weak cohesion to the fine solid particles, enabling them to coagulate with the large solid particles in the form of attachment, filling, and encapsulation during collisions, thereby achieving solid-liquid separation and ensuring the reduction or even disappearance of solid content in the coagulated material. In this invention, a coagulant agitator is installed at the center of a sealed coagulation tank. Through secondary stirring with high shear force, all residual polymer solids are precipitated. A nitrogen purging device is installed at the top of the sealed coagulation tank, corresponding to the interior of the tank. The signal output of the foam level sensor is connected to the signal input port of the controller, and the controller's control port is connected to the nitrogen output control unit. This effectively detects the foam layer on the liquid surface. When a foam layer appears, nitrogen purging eliminates the foam, effectively eliminating the foaming phenomenon of fluoroether emulsifiers and enabling automated purging without manual operation, greatly improving purging efficiency. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation
[0015] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.
[0016] Example 1, in Figure 1 This invention provides a coagulation device suitable for fluoroether carboxylic acid emulsions. It includes a closed coagulation tank 1, with a raw material inlet 2 at the top. A coagulant agitator 3 is installed at the center of the closed coagulation tank 1. The coagulant agitator 3 includes, from top to bottom, a drive motor 4, a drive shaft 5, and stirring blades 6. The drive motor 4 is installed outside the closed coagulation tank 1. The output end of the drive motor 4 is connected to the stirring blades 6 at the bottom via the drive shaft 5, which is inserted into the closed coagulation tank 1. The control end of the drive motor 4 is connected to a controller 7. The controller 7 can set the running time of the drive motor 4, thereby controlling the start and stop of the stirring operation of the stirring blade 6. A foam level sensor 8 is installed on the upper inner wall of the sealed coagulation tank 1, and a nitrogen purging device is installed on the top of the sealed coagulation tank 1. The nitrogen purging device corresponds to the inside of the sealed coagulation tank 1. The signal output terminal of the foam level sensor 8 is connected to the signal input port of the controller 7. The control port of the controller 7 is connected to the nitrogen output control unit. The nitrogen purging device used in this embodiment includes a high-pressure nitrogen tank 9, and the outlet of the high-pressure nitrogen tank 9 is connected to a pipeline. Pipe 10 is connected to several high-pressure nozzles 11 distributed on the top of the sealed condensation tank 1. In this embodiment, the sealed condensation tank 1 has two high-pressure nozzles 11 on the top, and the two high-pressure nozzles 11 point towards the inside of the sealed condensation tank 1. The nitrogen output control unit is set as a switching solenoid valve 12. The switching solenoid valve 12 is located on the pipe 10 and the control terminal of the switching solenoid valve 12 is connected to the control port of the controller 7. When the foam level sensor 8 detects that a large amount of foam has formed on the liquid surface inside the sealed condensation tank 1, the foam level sensor 8 sends a foam signal to the controller 7, and the controller 7 issues a signal. The instruction is given to the solenoid valve 12. After the solenoid valve 12 opens, the nitrogen gas from the high-pressure nitrogen tank 9 is input into the high-pressure nozzle 11 and sprayed into the sealed condensation tank 1 through the high-pressure nozzle 11. The sprayed nitrogen gas disperses the foam layer on the liquid surface in the sealed condensation tank 1. After the foam layer is dispersed, the foam level sensor 8 detects that the foam layer has dispersed and sends a signal to the solenoid valve 12. After the solenoid valve 12 closes, the nitrogen injection stops. In this embodiment, the controller 7 is set as a PLC controller, and the foam level sensor 8 is set as a capacitive foam sensor.
[0017] This invention also discloses a coagulation method suitable for fluoroether carboxylic acid emulsions, which includes the following steps: Step 1, Prepare raw materials: Based on the amount of polytetrafluoroethylene emulsion with a solid content of 12.5%, by weight, when the polytetrafluoroethylene emulsion is 1000 parts, succinic acid is 0.5 parts and sodium hydroxide is 1 part. Step 2: PEP (polytetrafluoroethylene) emulsion is discharged into a closed coagulation tank 1, and then the coagulation aid succinic acid is added to the closed coagulation tank 1 and mixed with the PEP emulsion. Step 3: Start the coagulant agitator and increase the agitation speed. Within the first agitation time set by controller 7, perform the first high-shear agitation on the mixture of polytetrafluoroethylene emulsion and succinic acid. The agitation speed for the first high-shear agitation is 300 rpm, and the mass percentage concentration of succinic acid is 5%-10%. After the set running time is reached, stop the coagulant agitator. At this point, solid powder appears on the surface of the mixture in the sealed coagulation tank 1 after agitation. Then, pour the prepared plasticizer sodium hydroxide solution into the sealed coagulation tank 1, causing a large number of bubbles to form on the surface, thus creating a foam layer. In this embodiment, the mass percentage concentration of the sodium hydroxide solution is 10%. Step 4: When the foam level sensor 8 detects the foam layer formed on the liquid surface in the sealed condensation tank 1, the foam level sensor 8 sends a signal to the controller 7. The controller 7 controls the switch solenoid valve 12 to open, and the nitrogen from the high-pressure nitrogen tank 9 is sprayed into the sealed condensation tank 1 through the high-pressure nozzle 11 to purge the foam layer on the liquid surface. After the foam layer dissipates, the foam level sensor 8 controls the switch solenoid valve 12 to close through the controller 7, stopping the nitrogen spraying and purging. Step 5: Start the coagulant agitator for a second high-shear agitation. The agitation speed for the second high-shear agitation is 300 rpm. The agitator is used to perform a second agitation in the sealed coagulation tank 1 for the second running time set by the controller 7. After the set running time is reached, the coagulant agitator is stopped. At this time, the mixture after agitation achieves solid-liquid separation and coagulation is completed. Then, the coagulated material is washed with water and discharged. The conductivity of the residual liquid in the discharged coagulated material is measured to be ≤10μs / cm.
[0018] The coagulation method of the present invention is further illustrated below through two embodiments. Example
[0019] Step 1, Prepare raw materials: Prepare 15 kg of polytetrafluoroethylene emulsion with a solid content of 12.5%, 7.5 g of succinic acid solution with a mass percentage of 5%, and 15 g of sodium hydroxide solution with a mass percentage of 10%. Step 2: 15 kg of polytetrafluoroethylene emulsion is discharged into a 28 L closed coagulation tank 1, and then 7.5 g of coagulation aid succinic acid is added to the closed coagulation tank 1 and mixed with the polytetrafluoroethylene emulsion. Step 3: Start the coagulant agitator and increase the agitation speed. Within the first 5-minute agitation time set by controller 7, perform the first high-shear agitation on the mixture of polytetrafluoroethylene emulsion and succinic acid. The agitation speed of the first high-shear agitation of the coagulant agitator is 300 rpm, and the mass percentage concentration of succinic acid is 5%-10%. After 5 minutes, stop the coagulant agitator. At this time, solid powder appears on the surface of the mixture in the sealed coagulation tank 1 after agitation. Then, pour 15g of the prepared 10% sodium hydroxide solution of plasticizer into the sealed coagulation tank 1, which generates a large number of bubbles on the surface of the liquid, thereby forming a foam layer on the surface of the liquid. Step 4: When the foam level sensor 8 detects the foam layer formed on the liquid surface in the sealed condensation tank 1, the foam level sensor 8 sends a signal to the controller 7. The controller 7 controls the switch solenoid valve 12 to open, and the nitrogen from the high-pressure nitrogen tank 9 is sprayed into the sealed condensation tank 1 through the high-pressure nozzle 11 to purge the foam layer on the liquid surface. After the foam layer dissipates, the foam level sensor 8 controls the switch solenoid valve 12 to close through the controller 7, stopping the nitrogen spraying and purging. Step 5: Start the coagulant agitator for a second high-shear agitation. The agitation speed for the second high-shear agitation is 300 rpm. The agitator is used to perform a second agitation in the sealed coagulation tank 1 for a second running time of 10 minutes set by controller 7. After 10 minutes, the coagulant agitator is stopped. At this time, the mixture after agitation achieves solid-liquid separation and coagulation is completed. Then, the coagulated material is washed with water and discharged. The conductivity of the residual liquid in the discharged coagulated material is measured to be ≤10μs / cm. Example
[0020] Step 1, Prepare raw materials: Prepare 3.2t of polytetrafluoroethylene emulsion with a solid content of 12.5%, 1.6kg of succinic acid solution with a mass percentage of 5%, and 3.2kg of sodium hydroxide solution with a mass percentage of 10%. Step two: Discharge 3.2t of polytetrafluoroethylene emulsion into a 5.5m³ volume container. 3 The coagulation aid 1.6 kg of succinic acid was added to the sealed coagulation tank 1 and mixed with the polytetrafluoroethylene emulsion. Step 3: Start the coagulant agitator and increase the agitation speed. Within the first 5-minute agitation time set by controller 7, perform the first high-shear agitation on the mixture of polytetrafluoroethylene emulsion and succinic acid. The agitation speed of the first high-shear agitation of the coagulant agitator is 300 rpm, and the mass percentage concentration of succinic acid is 5%-10%. After 5 minutes, stop the coagulant agitator. At this time, solid powder appears on the surface of the mixture in the sealed coagulation tank 1 after agitation. Then, pour 3.2 kg of the prepared 10% sodium hydroxide solution of plasticizer into the sealed coagulation tank 1, which generates a large number of bubbles on the surface of the liquid, thereby forming a foam layer on the surface of the liquid. Step 4: When the foam level sensor 8 detects the foam layer formed on the liquid surface in the sealed condensation tank 1, the foam level sensor 8 sends a signal to the controller 7. The controller 7 controls the switch solenoid valve 12 to open, and the nitrogen from the high-pressure nitrogen tank 9 is sprayed into the sealed condensation tank 1 through the high-pressure nozzle 11 to purge the foam layer on the liquid surface. After the foam layer dissipates, the foam level sensor 8 controls the switch solenoid valve 12 to close through the controller 7, stopping the nitrogen spraying and purging. Step 5: Start the coagulant agitator for a second high-shear agitation. The agitation speed for the second high-shear agitation is 300 rpm. The agitator is used to perform a second agitation in the sealed coagulation tank 1 for a second running time of 10 minutes set by controller 7. After 10 minutes, the coagulant agitator is stopped. At this time, the mixture after agitation achieves solid-liquid separation and coagulation is completed. Then, the coagulated material is washed with water and discharged. The conductivity of the residual liquid in the discharged coagulated material is measured to be ≤10μs / cm.
[0021] Not limited to this, any variations or substitutions conceived without inventive effort should be included within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope defined in the claims.
Claims
1. A coagulation device suitable for fluorine ether carboxylic acid emulsion, characterized in that It includes a closed condensation barrel (1), the raw material inlet (2) is arranged at the top of the closed condensation barrel (1), the condensing agent stirrer (3) is installed at the central position of the closed condensation barrel (1), the condensing agent stirrer (3) comprises a driving motor (4), a driving shaft (5) and a stirring paddle (6) from top to bottom, the driving motor (4) is installed outside the closed condensation barrel (1), the output end of the driving motor (4) is connected with the stirring paddle (6) at the bottom through the driving shaft (5) inserted into the closed condensation barrel (1), the control end of the driving motor (4) is connected with the controller (7), the controller (7) can set the running time of the driving motor (4), so as to control the start and stop of the stirring operation of the stirring paddle (6), the foam liquid level sensor (8) is installed on the inner wall of the upper part of the closed condensation barrel (1), the nitrogen blowing device is installed at the top of the closed condensation barrel (1) and corresponds to the inside of the closed condensation barrel (1), the signal output end of the foam liquid level sensor (8) is connected with the signal input port of the controller (7) in correspondence, and the control port of the controller (7) is connected with the nitrogen output control unit.
2. The coagulation device suitable for fluoroether carboxylic emulsion according to claim 1, characterized in that The nitrogen blowing device comprises a high-pressure nitrogen tank (9), the outlet of the high-pressure nitrogen tank (9) is connected with a plurality of high-pressure nozzles (11) distributed at the top of the closed condensation barrel (1) through a pipeline (10), the plurality of high-pressure nozzles (11) are directed to the inside of the closed condensation barrel (1), the nitrogen output control unit is provided as a switch electromagnetic valve (12), the switch electromagnetic valve (12) is located on the pipeline (10) and the control end of the switch electromagnetic valve (12) is connected with the control port of the controller (7), when the foam liquid level sensor (8) detects that a large amount of foam is formed on the liquid surface in the closed condensation barrel (1), the foam signal is transmitted to the controller (7) by the foam liquid level sensor (8), the controller (7) sends an instruction to the switch electromagnetic valve (12), after the switch electromagnetic valve (12) is opened, the nitrogen of the high-pressure nitrogen tank (9) is input into the high-pressure nozzles (11) and is sprayed into the closed condensation barrel (1) through the high-pressure nozzles (11), so that the foam layer on the liquid surface in the closed condensation barrel (1) is blown away by the nitrogen flow sprayed, when the foam layer is blown away, the signal is sent to the switch electromagnetic valve (12) by the foam liquid level sensor (8) after the foam layer is dispersed, and the switch electromagnetic valve (12) is closed to stop the spraying of nitrogen.
3. The coagulation device suitable for fluoroether carboxylic emulsion according to claim 1 or 2, characterized in that The controller (7) is provided as a PLC controller.
4. The coagulation device for fluoroether carboxylic emulsion according to claim 1 or 2, characterized by The foam liquid level sensor (8) is provided as a capacitive foam sensor.
5. A coacervation process suitable for fluorine ether carboxylic acid emulsions, characterized by It comprises the following steps: Step one, preparing raw materials: taking the addition amount of polytetrafluoroethylene emulsion with a solid content of 12.5% as the benchmark, when the polytetrafluoroethylene emulsion is 1000 parts, 0.5 parts of succinic acid and 1 part of sodium hydroxide are added; Step two, the polytetrafluoroethylene emulsion is discharged into the closed condensation barrel (1), and then the condensation aid succinic acid is added into the closed condensation barrel (1) to mix with the polytetrafluoroethylene emulsion; Step three, start the coagulant agitator, and increase the stirring speed, the first high shear stirring of the mixed solution of polytetrafluoroethylene emulsion and succinic acid in the first stirring time set by the controller (7), when the set running time is over, stop the coagulant agitator, at this time, solid powder appears on the liquid surface in the closed coagulation barrel (1) after stirring, then pour the prepared plasticizing agent sodium hydroxide solution into the closed coagulation barrel (1), so that a large amount of bubbles are generated on the liquid surface, thereby forming a foam layer on the liquid surface; Step four, when the foam liquid level sensor (8) detects the foam layer formed on the liquid surface in the closed coagulation barrel (1), the foam liquid level sensor (8) sends a signal to the controller (7), the controller (7) controls the on-off electromagnetic valve (12) to open, the nitrogen gas in the high-pressure nitrogen gas tank (9) is sprayed into the closed coagulation barrel (1) through the high-pressure nozzle (11) to blow the foam layer on the liquid surface, when the foam layer disappears, the foam liquid level sensor (8) controls the on-off electromagnetic valve (12) to close through the controller (7), stopping the nitrogen gas from being sprayed and blown; Step five, start the coagulant agitator for the second time high shear stirring, the second stirring in the closed coagulation barrel (1) is carried out in the second running time set by the controller (7), when the set running time is over, stop the coagulant agitator, at this time, the mixture after stirring realizes solid-liquid separation, and the coagulation is completed, then the coagulum is washed after water change and discharged, the residual liquid conductivity in the coagulum after discharge is measured to be ≤10 μs / cm.
6. The coacervation process suitable for fluoroether carboxylic acid emulsions as claimed in claim 5, wherein The mass percentage concentration of sodium hydroxide solution is 10%.
7. The coacervation process suitable for fluoroether carboxylic acid emulsions as claimed in claim 5, wherein The stirring speed of the coagulant agitator for the first and second high shear stirring is 300 rpm.
8. The coacervation process suitable for fluoroether carboxylic acid emulsions as claimed in claim 5, wherein The mass percentage concentration of succinic acid is 5%-10%.