A final polycondensation reactor for producing high quality PA66 polymer

Abstract

The utility model belongs to polymer production equipment technical field relates to a kind of final polycondensation reactor of preparation high-quality PA66 polymer, final polycondensation reactor is horizontal reactor, including shell and the stirring device located in shell interior, shell is equipped with feed inlet, discharge port and gas phase mouth, shell is circular truncated cone shell, circular truncated cone shell is inclined from large end to small end, and the direction of inclination is downward;Stirring device is made of transmission shaft and stirrer fixed on transmission shaft;Transmission shaft is parallel with the center line of circular truncated cone shell;Stirrer includes first stirrer close to feed inlet, third stirrer close to discharge port and second stirrer between first stirrer and third stirrer;First stirrer is made of several center hole disc and several spiral belt fixed on disc.The utility model's final polycondensation reactor ensures the controllable continuous stable propulsion of polymer in polymerization process, prevents polymer backmixing, effectively improves PA66 product quality.

Description

Technical Field

[0001] This utility model belongs to the technical field of polymer production equipment, and relates to a final polycondensation reactor for preparing high-quality PA66 polymer. Background Technology

[0002] Currently, the main route for the continuous production of polyhexamethylene adipamide (PA66) from hexamethylenediamine and adipic acid is: salt formation - concentration - prepolymerization - flash evaporation - final polycondensation process. The production process involves various types of reaction equipment, among which the final polycondensation reactor is the key equipment in the entire process and the final polymerization equipment for PA66, playing a decisive role in the quality of the PA66 product. Current industrial continuous polymerization reactors for PA66 production are typically vertical stirred reactors. These reactors are fully mixed reactors, which can lead to polymer backmixing during continuous production. This results in inconsistent residence times of the polymer within the final polymerization reactor, leading to significant fluctuations in the molecular weight of the produced PA66 and lower product quality, limiting its application range, particularly in high-speed spinning of civilian filaments. Horizontal spiral reactors are also used, typically employing a set of helical blades of equal diameter as agitators. However, these struggle to match changes in polymer viscosity during polymerization, and the consistency of polymer melt residence time remains to be improved. Specifically, as polymer viscosity increases, the polymer film thickness on the helical blades continuously increases. When the film reaches a certain thickness, the highly viscous polymer cannot detach from the helical blades in time, reducing film renewal and increasing the risk of backmixing. Furthermore, long-term adhesion to the helical blades can lead to thermal degradation reactions, producing gel particles. Therefore, the quality uniformity of PA66 produced by horizontal spiral reactors still cannot meet the required standards.

[0003] Other final polycondensation reactors suitable for step-growth polymerization typically employ a cylindrical shell. Their internal stirring structures include disc, cage, and spiral types, often combined to accommodate changes in polymer viscosity during the final polycondensation process, as specified in CN 110280202 B and CN 111672443 B. Disc and cage types, or equivalent structures, are commonly used in the low and medium viscosity zones, respectively. The high viscosity zone, using a spiral or equivalent structure, results in polymer propulsion in the low and medium viscosity zones relying solely on liquid level difference (i.e., gravity), limiting control over polymer residence time. The high viscosity zone also suffers from backmixing and thermal degradation issues similar to those found in horizontal spiral reactors, leading to polymer quality deterioration.

[0004] Therefore, it is of great significance to study a final polycondensation reactor for preparing high-quality PA66 polymer in order to solve the problems existing in the prior art. Utility Model Content

[0005] The purpose of this invention is to solve the problems existing in the prior art and provide a final polycondensation reactor for preparing high-quality PA66 polymer.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A final polycondensation reactor for preparing high-quality PA66 polymer is a horizontal reactor, including an outer shell and a stirring device located inside the outer shell. The outer shell is provided with a feed inlet, a discharge outlet and a gas phase inlet. The outer shell is a frustum-shaped shell, which is inclined from the large end to the small end, and the inclination direction is downward. The stirring device consists of a drive shaft and a stirrer fixed on the drive shaft.

[0008] The drive shaft is parallel to the centerline of the frustum-shaped outer casing;

[0009] The agitator includes a first agitator near the feed inlet, a third agitator near the discharge outlet, and a second agitator located between the first and third agitators; the three agitators divide the final polycondensation reactor from the feed inlet to the discharge outlet into different viscosity zones, namely, the first agitator corresponds to the low viscosity zone, the second agitator corresponds to the medium viscosity zone, and the third agitator corresponds to the high viscosity zone.

[0010] The first stirrer consists of several discs with central holes and several spiral bands fixed on the discs. The discs are concentrically and equally spaced vertically fixed on the drive shaft through the central holes.

[0011] The second agitator includes a spiral structure, which is fixed on the drive shaft;

[0012] The third agitator includes a screw propeller, which is fixed to the drive shaft.

[0013] This invention is applicable to the production of medium-to-high viscosity PA66 polymers with a relative viscosity of 2.5 to 3.3 using the sulfuric acid process.

[0014] Because polyamides are particularly prone to degradation and gel formation, more stringent control of melt backmixing during the polymerization process is required. This is to prevent melt backmixing from causing inconsistent residence times and reducing the uniformity of polyamide molecular weight, and to prevent melt backmixing from increasing residence time and thus increasing gelation.

[0015] The first, second, and third stirrers employ different structures to match the changes in polymer viscosity during the polymerization process, control the polymer liquid film area and thickness on the stirrer, enhance mass transfer, and achieve thermodynamic enhancement of the polymerization process.

[0016] During rotation, the surface of the disc constituting the first stirrer forms a large amount of liquid film. The curved frame formed by the helical ribbon and the disc achieves a film-stretching effect, resulting in good mass transfer and promoting the reaction and the devolatilization of small molecule byproducts. The helical ribbon also provides axial propulsion force to the polymer. In addition, because the disc and helical ribbon are at a certain angle to the horizontal plane, the liquid film formed by the disc and helical ribbon drips towards the discharge port due to gravity, causing both the liquid film and the polymer in the melt pool to propel towards the discharge port, improving the consistency of polymer residence time.

[0017] In addition to its axial propulsion function, the spiral belt also acts as a scraper, removing polymer melt adhering to the inner shell of the reactor within the gaps between the discs, thus preventing prolonged residence time. Under the action of the aforementioned first agitator, the low-viscosity zone not only enhances the polymerization reaction but also allows the polymer melt in the liquid film and melt pool to advance synchronously towards the discharge port, preventing backmixing and adhesion of the polymer melt and improving the consistency of polymer melt residence time.

[0018] The second agitator also causes the polymer in the liquid film and melt pool to move synchronously toward the discharge port, improving the consistency of residence time.

[0019] Both the first and second stirrers described above adapt to changes in polymer melt viscosity, possessing suitable film-forming area and film-falling effect, increasing the devolatilization effect of small molecules, and thus enhancing the polymerization reaction. Simultaneously, the structure of the first and second stirrers of this invention allows for controllable, continuous, and synchronous propagation of the polymer in the liquid film and melt pool towards the discharge port, improving the consistency of polymer residence time and facilitating the preparation of high-quality polymers.

[0020] When the polymer melt reaches the third agitator area, the reactor is completely filled. The use of a screw propeller ensures a high degree of contact between the agitator and the reactor's inner wall, achieving forced propulsion and discharge towards the outlet. This prevents back-mixing of the high-viscosity polymer melt in this area and ensures uniform residence time. Furthermore, the third agitator of this invention also achieves the effect of forced discharge via an external screw, reducing the number of components and lowering costs.

[0021] This invention utilizes the synergistic effect of the aforementioned horizontal frustum-shaped shell and the first, second, and third stirrers with different structures to ensure that the polymer melt is continuously and synchronously propelled throughout the entire polycondensation process. This improves the consistency of the polymer melt residence time, which is beneficial for preparing high-quality polymers.

[0022] As a preferred technical solution:

[0023] As described above, in a final polycondensation reactor for preparing high-quality PA66 polymer, the inlet and outlet are located at the bottom of the side of a frustum-shaped outer shell, with the inlet near the large end of the frustum-shaped outer shell and the outlet near the small end of the frustum-shaped outer shell. This allows the polymer liquid level change to match the change in the shape of the final polycondensation reactor shell, thereby improving the space utilization of the final polycondensation reactor.

[0024] The gas phase port is located at the upper middle position of the side of the frustum-shaped outer shell. This is because when the polymer moves to the high viscosity zone in this invention, the liquid level fills the reactor, and the position of the gas phase port prevents the polymer melt from flowing out of the gas phase port.

[0025] As described above, a final polycondensation reactor for preparing high-quality PA66 polymer has a frustum-shaped outer shell comprising an inner layer and an outer layer, with the region between the inner and outer layers forming a jacket layer for storing a heat transfer medium; the vertical cross-sections of both the inner and outer layers through the centerline are isosceles trapezoids.

[0026] As described above, in a final polycondensation reactor for preparing high-quality PA66 polymer, the drive shaft is sealed and fixed on both sides of the axial direction of the frustum-shaped outer shell, and the drive shaft extends a certain distance on the side near the small end of the frustum-shaped outer shell (the setting of this distance is not particularly required, as long as it can be mechanically connected to the stirring motor) for connecting the stirring motor.

[0027] The fixed position of the drive shaft is not higher than the center line of the frustum-shaped outer shell; more preferably, the drive shaft is concentric with the center line of the frustum-shaped outer shell, so that the gap between the stirrer fixed on the drive shaft and the inner wall of the frustum-shaped outer shell remains unchanged during the rotation process, thus avoiding the problem of inconsistent residence time of polymer melt due to gap fluctuation.

[0028] The drive shaft is angled at 2.5° to 15° with the horizontal plane. This design serves two purposes: first, it matches the continuously decreasing liquid level during the polymerization process, improving the utilization rate of the agitator; second, it ensures that the polymer can be continuously propelled during the liquid film falling process because the agitator is at a certain angle to the horizontal plane. Furthermore, since the bottom of the reactor shell is parallel to the horizontal plane, this design avoids the problem of uncontrollable residence time of materials due to gravity caused by simply raising one end of a traditional cylindrical horizontal reactor.

[0029] As described above, a final polycondensation reactor for preparing high-quality PA66 polymer has a disc surface divided into multiple fan-shaped perforated areas and multiple fan-shaped partitioned areas, which are alternately distributed along the circumference of the disc; several spiral bands are used to connect several discs; the perforated areas on any adjacent discs do not completely overlap.

[0030] As described above, in a final polycondensation reactor for preparing high-quality PA66 polymer, the diameter of the disc gradually decreases from the inlet to the outlet, while the area of ​​the pores in the disc gradually increases. This matches the characteristic of the polymer's fluidity gradually deteriorating, controlling the amount of polymer during the film-forming process to prevent the liquid film from becoming too thick.

[0031] The distance between all the disks and the inner wall of the frustum-shaped shell is equal, meaning that the axes of all the disks are concentric with the frustum-shaped shell.

[0032] As described above, in a final polycondensation reactor for preparing high-quality PA66 polymer, several spiral ribbons are fixed to the edge of a disc or embedded in the partition area of ​​the disc (the partition area is a solid region, and the spiral ribbon is embedded and fixed in the opening with the same cross-sectional shape as the spiral ribbon by opening a hole in the solid edge); the minimum distance between all spiral ribbons and the inner wall of the frustum-shaped outer shell is equal; the cross-section of the spiral ribbon is streamlined, preferably teardrop-shaped, which is beneficial to improving the scraping effect and the dripping of polymer melt; the material of the spiral ribbon is nickel-plated stainless steel alloy.

[0033] As described above, the final polycondensation reactor for preparing high-quality PA66 polymer includes a spiral structure comprising several single-circumferential spiral blades, i.e., within one pitch, the spiral blades rotate exactly once around the drive shaft; the several single-circumferential spiral blades are concentric and vertically fixed on the drive shaft; from the feed inlet to the discharge outlet, the diameter and pitch of the single-circumferential spiral blades, as well as the spacing between adjacent single-circumferential spiral blades, gradually decrease. This is to take into account the change in polymer melt viscosity during the polymerization process. While promoting the continuous advancement of the polymer melt, the spiral structure can control the amount of liquid carried during the film-forming process and the thickness of the liquid film on the spiral blades, avoiding problems such as difficult devolatilization and increased residence time caused by excessively thick liquid films;

[0034] The minimum distance between all single-cycle helical blades and the inner wall of the frustum-shaped outer shell is equal.

[0035] As described above, in a final polycondensation reactor for preparing high-quality PA66 polymer, the second stirrer further includes thin rods fixed to the edges of single-circumferential helical blades and connecting all the blades. The projections of the thin rods and the drive shaft on the horizontal plane are parallel, thus forming a surface mesh on the surface of all helical blades and between their spacing. This surface mesh provides a film-stretching effect, and the ample space beneath the mesh facilitates film falling, increasing the devolatilization effect of small molecules and thus enhancing the polymerization reaction. The axial thin rods of the surface mesh also act as scrapers, with the same effect as the helical belt in the first reactor, preventing adverse conditions such as thermal degradation caused by prolonged residence of the polymer melt on the reactor inner wall.

[0036] As described above, in a final polycondensation reactor for preparing high-quality PA66 polymer, the screw propeller consists of continuous helical blades, which are vertically fixed to the drive shaft. From the inlet to the outlet, the diameter and pitch of the continuous helical blades gradually decrease. The minimum distance between all helical blades and the inner wall of the frustum-shaped outer shell is equal. When the polymer melt reaches the third agitator area, its liquid level completely fills the reactor. By employing variable-pitch, variable-diameter helical blades, the agitator maintains a high degree of contact with the inner wall of the reactor, achieving forced propulsion and discharge towards the outlet. This prevents backmixing of the high-viscosity polymer melt in this area and ensures uniform residence time of the polymer melt.

[0037] Beneficial effects:

[0038] (1) The present invention provides a final polycondensation reactor for preparing high-quality PA66 polymer. It is a horizontal frustum-shaped polycondensation reactor with a stirring device with a certain inclination angle inside. It also has three types of stirrers with different structures according to the viscosity changes during the polymer polymerization process. This ensures the controllable, continuous and stable propulsion of the polymer during the polymerization process and the matching of the stirrer with the polymer liquid level and viscosity, so that the residence time distribution of the polymer is controllable.

[0039] (2) The present invention provides a final polycondensation reactor for preparing high-quality PA66 polymer. The high viscosity zone corresponding to the third stirrer prevents polymer back-mixing through forced propulsion, effectively improving the quality of PA66 products. The equipment is simple and reduces costs.

[0040] (3) The present invention provides a final polycondensation reactor for preparing high-quality PA66 polymer. It has a simple structure, saves the number of components, reduces the factory floor area and lowers the cost, and improves the space utilization rate of the final polycondensation reactor. Attached Figure Description

[0041] Figure 1 This is a front sectional view of a schematic diagram of a reaction vessel;

[0042] Figure 2 This is a front view of the disc of the first stirrer; the blank areas in the figure represent the perforated areas, and the shaded areas represent the partition areas.

[0043] Figure 3 This is a schematic diagram of the cross-section of the spiral band of the first stirrer;

[0044] Figure 4 This is a schematic diagram of the second stirrer;

[0045] Among them, 1-inlet, 2-outlet, 3-gas phase inlet, 4-drive shaft, 5-first agitator, 51-disc, 52-spiral ribbon, 53-hole area, 54-partition area, 55-cross section of spiral ribbon, 6-third agitator, 61-thin rod, 62-single-circumferential spiral blade, 7-second agitator. Detailed Implementation

[0046] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0047] The test methods involved in the performance indicators of this utility model are as follows:

[0048] Relative viscosity: determined according to the sulfuric acid method in HG / T4182-2012 standard;

[0049] Molecular weight distribution: The molecular weight distribution was determined by gel permeation chromatography. The instrument used was an Agilent 1260 gel permeation chromatograph, the column was an Agilent HFIP series column, the mobile phase was hexafluoroisopropanol and sodium trifluoroacetate, the concentration of sodium trifluoroacetate in the mobile phase was 0.02M, the test temperature was 40℃, and the standard was Agilent PMMA narrow distribution standard.

[0050] A final polycondensation reactor for preparing high-quality PA66 polymer is a horizontal reactor, such as... Figure 1 As shown, it includes an outer shell and a stirring device located inside the outer shell. The outer shell is provided with a feed inlet 1, a discharge outlet 2 and a gas phase outlet 3. The outer shell is a frustum-shaped shell, which is inclined from the large end to the small end, and the inclination direction is downward.

[0051] The inlet 1 and outlet 2 are located at the bottom of the side of the frustum-shaped shell, with the inlet 1 close to the large end of the frustum-shaped shell and the outlet 2 close to the small end of the frustum-shaped shell.

[0052] The gas inlet 3 is located at the upper middle position on the side of the frustum-shaped outer shell;

[0053] The frustum-shaped outer shell consists of an inner layer and an outer layer. The area between the inner and outer layers forms a jacket layer, which is used to hold the heat medium. The vertical cross-sections of both the inner and outer layers through the centerline are isosceles trapezoids.

[0054] The stirring device consists of a drive shaft 4 and a stirrer fixed on the drive shaft 4;

[0055] The drive shaft 4 is sealed and fixed on both sides of the axial direction of the frustum-shaped outer shell, and the drive shaft 4 extends a certain distance on the side near the small end of the frustum-shaped outer shell to connect the stirring motor.

[0056] The fixed position of the drive shaft 4 is not higher than the center line of the frustum-shaped outer shell, and the drive shaft 4 is parallel to the center line of the frustum-shaped outer shell; preferably, the drive shaft is concentric with the center line of the frustum-shaped outer shell.

[0057] The drive shaft 4 forms an angle of 2.5° to 15° with the horizontal plane;

[0058] The agitator includes a first agitator 5 near the feed inlet, a third agitator 6 near the discharge outlet, and a second agitator 7 located between the first agitator 5 and the third agitator 6; the three agitators divide the final polycondensation reactor from the feed inlet to the discharge outlet into different viscosity zones, namely, the first agitator corresponds to the low viscosity zone, the second agitator corresponds to the medium viscosity zone, and the third agitator corresponds to the high viscosity zone.

[0059] The first stirrer 5 consists of several discs 51 with central holes and several spiral bands 52 fixed on the discs 51. The discs 51 are concentrically and equally spaced vertically fixed on the drive shaft 4 through the central holes.

[0060] like Figure 2 As shown, the surface of the disk 51 is divided into multiple hole areas 53 and multiple partition areas 54, which are alternately distributed along the circumference of the disk 51; several spiral bands 52 are used to connect several disks 51; the hole areas 53 on any adjacent disks 51 do not completely overlap.

[0061] From the feed inlet 1 to the discharge outlet 2, the diameter of the disc 51 gradually decreases, and the area of ​​the hole region 53 of the disc 51 gradually increases.

[0062] The distance between all disks 51 and the inner wall of the frustum-shaped outer shell is equal, that is, the axis of all disks 51 is concentric with the frustum-shaped outer shell.

[0063] Several spiral bands 52 are fixed to the edge of the disk 51 or embedded in the partition area 54 of the disk 51 to connect the disks 51; the minimum distance between all spiral bands 52 and the inner wall of the frustum-shaped outer shell is equal; such as Figure 3 As shown, the cross-section 55 of the spiral strip is teardrop-shaped; the material of the spiral strip 52 is nickel-plated stainless steel alloy.

[0064] like Figure 4As shown, the second agitator 7 includes a spiral structure and a thin rod 61. The spiral structure is fixed on the drive shaft 4. The spiral structure includes several single-circumferential spiral blades 62. The several single-circumferential spiral blades 62 are concentric and vertically fixed on the drive shaft 4. From the feed inlet 1 to the discharge outlet 2, the diameter and pitch of the single-circumferential spiral blades 62 and the spacing between adjacent single-circumferential spiral blades 62 gradually decrease.

[0065] The minimum distance between all single-cycle helical blades 62 and the inner wall of the frustum-shaped outer shell is equal;

[0066] The thin rod 61 is fixed to the edge of the single-circumferential spiral blade 62 and connects all the single-circumferential spiral blades 62; the projection of the thin rod 61 and the drive shaft on the horizontal plane is parallel;

[0067] The third agitator 6 includes a screw propeller, which is fixed on the drive shaft 4;

[0068] The propeller consists of continuous helical blades, which are vertically fixed on the drive shaft. The diameter and pitch of the continuous helical blades gradually decrease from the inlet to the outlet. The minimum distance between all the helical blades and the inner wall of the frustum-shaped outer shell is equal.

[0069] Specific usage process: The prepolymerized atmospheric pressure melt (PA66 oligomer with a number average molecular weight of 10000 g / mol) flows into the final polycondensation reactor of this invention through the feed inlet. The melt gradually moves to the discharge outlet, and the melt temperature is controlled between 277℃ and 285℃, with a temperature fluctuation of ±0.1℃. Depending on the relative viscosity of the prepared PA66, the stirrer speed can be adjusted between 5 rpm and 150 rpm; the average melt level is 1 / 3 to 1 / 2 (the level refers to the ratio of the total melt volume in the final polycondensation reactor to the total volume of the final polycondensation reactor), and the residence time of the melt in the final polycondensation reactor of this invention is between 10 min and 120 min.

[0070] A specific PA66 polymer was prepared using the aforementioned final polycondensation reactor. The parameters of the final polycondensation reactor are as follows:

[0071] The large end face of the frustum-shaped outer shell has a diameter of 1m, the small end face has a diameter of 0.37m, and the angle between the drive shaft and the horizontal plane is 6°.

[0072] There are 2 discs, 3 spiral bands on the discs, and the distance between the two discs is 0.5m. Each disc consists of 8 hole areas and 8 partition areas.

[0073] From the inlet to the outlet, the area of ​​the perforated area of ​​the disc gradually increases, accounting for 40% and 60% of the total area of ​​the disc, respectively.

[0074] The spiral strips are fixed at equal intervals in the partition area of ​​the disc;

[0075] The number of single-cycle helical blades is 3, and the number of thin rods is 3;

[0076] The distance between the aforementioned spiral band and thin rod and the inner wall of the frustum-shaped outer shell is 1 mm;

[0077] From the inlet to the outlet, the spacing between the single-cycle spiral blades gradually decreases, to 0.4m and 0.25m respectively;

[0078] From the feed inlet to the discharge outlet, the pitch of the continuous spiral blades gradually decreases to 0.25m, 0.2m, and 0.15m respectively, and the distance between the spiral blades and the inner wall of the frustum-shaped outer shell is 10mm.

[0079] The preparation process parameters are as follows:

[0080] The melt temperature was 283℃, the stirrer speed was 20 rpm, the residence time was 40 min, and the average melt level was 1 / 3.

[0081] The obtained PA66 has a relative viscosity of 2.4, a number-average molecular weight of 17000 g / mol, and a molecular weight distribution of 1.78.

Claims

1. A final polycondensation reactor for preparing high-quality PA66 polymer, which is a horizontal reactor, comprising a shell and a stirring device located inside the shell, wherein the shell is provided with a feed inlet (1), a discharge outlet (2) and a gas phase inlet (3), characterized in that: The outer shell is a frustum-shaped shell, which is inclined from the large end to the small end, and the inclination direction is downward; the stirring device consists of a drive shaft (4) and a stirrer fixed on the drive shaft (4); The drive shaft (4) is parallel to the centerline of the frustum-shaped outer shell; The agitator includes a first agitator (5) near the feed inlet, a third agitator (6) near the discharge outlet, and a second agitator (7) located between the first agitator (5) and the third agitator (6); The first stirrer (5) consists of several discs (51) with central holes and several spiral bands (52) fixed on the discs (51). The discs (51) are concentrically and equally spaced vertically fixed on the drive shaft (4) through the central holes. The second stirrer (7) includes a spiral structure, which is fixed on the drive shaft (4); The third agitator (6) includes a screw propeller, which is fixed to the drive shaft (4).

2. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 1, characterized in that, The inlet (1) and outlet (2) are located at the bottom of the side of the frustum-shaped shell, with the inlet (1) close to the large end of the frustum-shaped shell and the outlet (2) close to the small end of the frustum-shaped shell. The gas inlet (3) is located at the upper middle position on the side of the frustum-shaped outer shell.

3. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 2, characterized in that, The frustum-shaped outer shell consists of an inner layer and an outer layer. The area between the inner and outer layers forms a jacket layer, which is used to hold the heat medium. The vertical cross-sections of both the inner and outer layers through the center line are isosceles trapezoids.

4. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 3, characterized in that, The drive shaft (4) is sealed and fixed on both sides of the axial direction of the frustum-shaped outer shell, and the drive shaft (4) extends a certain distance on one side near the small end of the frustum-shaped outer shell to connect the stirring motor. The fixed position of the drive shaft (4) is not higher than the center line of the frustum-shaped outer shell; The transmission shaft (4) is at an angle of 2.5° to 15° to the horizontal plane.

5. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 4, characterized in that, The surface of the disk (51) is divided into multiple hole areas (53) and multiple partition areas (54), which are alternately distributed along the circumference of the disk (51); several spiral bands (52) are used to connect several disks (51); the hole areas (53) on any adjacent disks (51) do not completely overlap.

6. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 5, characterized in that, From the feed inlet (1) to the discharge outlet (2), the diameter of the disc (51) gradually decreases, and the area ratio of the hole area (53) of the disc (51) gradually increases; All disks (51) are equidistant from the inner wall of the frustum-shaped outer shell.

7. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 6, characterized in that, Several spiral strips (52) are fixed to the edge of the disk (51) or embedded in the partition area (54) of the disk (51) to connect the disks (51); the minimum distance between all spiral strips (52) and the inner wall of the frustum-shaped shell is equal; the cross-section of the spiral strip is streamlined.

8. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 7, characterized in that, The spiral structure includes several single-circumferential spiral blades (62), which are concentric and vertically fixed on the drive shaft (4); from the feed inlet (1) to the discharge outlet (2), the diameter and pitch of the single-circumferential spiral blades (62) and the spacing between adjacent single-circumferential spiral blades (62) gradually decrease. The minimum distance between all single-cycle helical blades (62) and the inner wall of the frustum-shaped outer shell is equal.

9. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 8, characterized in that, The second stirrer (7) also includes a thin rod (61) which is fixed to the edge of the single-circular spiral blade (62) and connects all the single-circular spiral blades (62); the projection of the thin rod (61) and the drive shaft on the horizontal plane is parallel.

10. The final polycondensation reactor for preparing high-quality PA66 polymer according to claim 9, characterized in that, The propeller consists of continuous helical blades, which are vertically fixed on the drive shaft. The diameter and pitch of the continuous helical blades gradually decrease from the inlet to the outlet. The minimum distance between all the helical blades and the inner wall of the frustum-shaped outer shell is equal.

Images