Polymer solvent removal separation equipment, solvent removal devices and solvent removal methods

Abstract

This invention relates to a polymer solvent removal separation device, a solvent removal apparatus, and a solvent removal method, specifically relating to the field of polymer recycling technology. The polymer solvent removal separation device includes: a polymer solution inlet, an annular baffle zone, a swirling umbrella-shaped distributor, an orifice plate zone, and a polymer outlet, connected in sequence; the annular baffle zone is provided with a solvent outlet. The polymer solvent removal separation device provided by this invention, through the combination of a specific swirling umbrella-shaped distributor and an orifice plate flow equalization assembly, allows the polymer solution to enter the separation device after heating. The swirling umbrella-shaped distributor transforms the solution into a swirling, wall-attached flow. The swirling flow generates centrifugal acceleration, which, combined with gravity, forms a synergistic separation force. The solution then passes through the orifice plate flow equalization assembly to form a spiral columnar laminar flow stream, achieving efficient phase separation in the phase separation zone under full liquid conditions. Ultimately, the top light phase is recycled, while the bottom heavy phase polymer content is increased to 60-70%.

Description

Technical Field

[0001] This invention relates to the field of polymer recycling technology, specifically to a polymer solvent removal separation device, solvent removal apparatus, and solvent removal method, and more particularly to a solvent separation device, solvent removal apparatus, and solvent removal method for removing solvent from a polymer solution. Background Technology

[0002] Flash devolatilization, as a fundamental separation technology in the chemical industry, is widely used in polymer synthesis, polymer recycling, and environmental treatment.

[0003] In common industrial solution polymerization processes, the most prevalent devolatilization method for homogeneous polymer solutions is heating and evaporating the solution. Because the molecular weights of polymers and solvents differ significantly, polymers exhibit a swelling effect in the solvent. High-concentration polymer solutions have high viscosity and extremely poor flowability, leading to difficulties in heat conduction and mass transfer. Therefore, the higher the polymer concentration, the more difficult it is to separate. Similarly, similar problems exist in the field of polymer recycling.

[0004] In current solvent-based polymer recovery processes, the crushed particles dissolve in the solvent. After filtration and precipitation, a polymer solution with a solid content of 40-50% is obtained. Some of the solvent also swells in the polymer and is difficult to remove.

[0005] To overcome the problems of polymer flowability during devolatilization and the difficulty of separation as polymer concentration increases, a "devolatilization + extrusion" process is often adopted. This process requires multi-stage heating followed by flash evaporation (usually three-stage heating + three-stage flash evaporation), and finally solvent removal in a vacuum extruder to meet product requirements. Given this process, the devolatilization process is complex and requires high energy consumption.

[0006] For example, US5599885A discloses a method for preparing polyolefins, which includes a liquid-liquid separation process. A polymer solution containing the resulting polyolefin, obtained from a polymerization process, is fed into a separation zone maintained at a temperature not lower than the supernatant point of the polymer solution. This separates the polymer solution into a lower phase containing a high concentration of polyolefin and an upper phase. The polyolefin is recovered from the lower phase in the separation zone, and at least a portion of the upper phase is recycled back to the polymerization zone. When maintained below the supernatant point, the resulting polymer solution is a homogeneous liquid phase; however, when maintained at a temperature not lower than the supernatant point, it separates into a concentrated phase and a dilute phase. Generally, there is a trend that the higher the temperature of the polymer solution not lower than the supernatant point, the higher the copolymer concentration in the concentrated phase, and conversely, the lower the copolymer concentration in the dilute phase. Furthermore, the greater the concentration difference between these two phases, the more efficient the phase separation, thus facilitating post-processing of the separated phases.

[0007] CN113164898A discloses a solution polymerization method in which the polymer solution exhibits a lower critical solution temperature (LCST) phenomenon. Thus, a homogeneous polymer solution will separate into a polymer-rich liquid phase and a solvent-rich phase above a certain temperature. This temperature is a function of solvent type, polymer stream composition, and pressure. Any of these variables can be manipulated to induce liquid-liquid separation using a heating and depressurization process, increasing the polymer solids content to 20-24% in a liquid-liquid separator.

[0008] The liquid-liquid separation methods mentioned in the prior art have very low associated heat loads, especially compared to the evaporation of an equal amount of solvent, saving a significant amount of energy. However, this method is suitable for homogeneous solutions after solution polymerization, where phase separation is achieved by adjusting the temperature above the upper cloud point. It is not applicable to polymer recovery processes. In solvent-based recovery processes, after the crushed particles dissolve, the polymer solution with a solid content of 40-50% is a two-phase solution (solid-liquid) at room temperature. As the temperature increases, the solid polymer transforms into a melt, resulting in significant stratification with the solvent. The polymer solution obtained from the solvent-based recovery process differs significantly from the homogeneous solution after solution polymerization.

[0009] In summary, current methods for solvent removal from polymer solutions still suffer from poor solvent removal efficiency and high energy consumption. Summary of the Invention

[0010] In view of the problems existing in the prior art, the purpose of the present invention is to provide a polymer solvent removal separation device, solvent removal apparatus and solvent removal method to solve the defects of poor solvent removal effect and high energy consumption when removing solvent from polymer solutions.

[0011] To achieve this objective, the present invention adopts the following technical solution:

[0012] In a first aspect, the present invention provides a polymer desolventizing and separation device, the polymer desolventizing and separation device comprising:

[0013] The polymer solution inlet, annular baffle zone, swirling umbrella distributor, orifice plate zone, and polymer outlet are connected in sequence.

[0014] The annular baffle area is provided with a solvent outlet.

[0015] The polymer desolventizing and separation equipment provided by this invention, through the combination of a specific swirling umbrella-shaped distributor and an orifice plate flow equalization component, allows the polymer solution to enter the separation equipment after heating. The swirling umbrella-shaped distributor transforms the solution into a swirling, wall-adhering flow. The swirling flow generates centrifugal acceleration, which, together with gravity, forms a synergistic separation force. The solution then passes through the orifice plate flow equalization component to form a spiral columnar laminar flow stream, achieving efficient phase separation in the phase separation zone under full liquid conditions. Finally, the light phase at the top is recycled, while the polymer content of the heavy phase at the bottom is increased to 60-70%.

[0016] As a preferred embodiment of the present invention, the inner diameter of the annular baffle area is 2 / 3 to 3 / 4 of the inner diameter of the polymer desolventizing and separating equipment.

[0017] Preferably, the height of the annular baffle area is 100-500mm.

[0018] As a preferred technical solution of the present invention, the swirl-type umbrella distributor includes a conical body with a cone angle of 60-90°.

[0019] Preferably, the surface of the swirl umbrella-shaped distributor is distributed with 6-24 arc-shaped guide plates.

[0020] Preferably, the arc angle of the arc-shaped guide plate is 15-60°.

[0021] Preferably, the distance between the end of the cyclone umbrella distributor and the inner wall of the polymer desolventizing and separating equipment is 100-500 mm.

[0022] As a preferred embodiment of the present invention, the perforated plate region includes at least one perforated plate.

[0023] Preferably, the perforated plate is a perforated plate with holes having a diameter of 20-40mm.

[0024] Preferably, the spacing between the holes on the perforated plate is 2-3 times the hole diameter.

[0025] Preferably, the diameter of the orifice plate is 90-95% of the inner diameter of the polymer desolventizing separation device.

[0026] Preferably, the spacing between adjacent perforated plates is 0.5-1.5m.

[0027] Preferably, the orifice plate area is located 0.5-1.5m below the swirl-type umbrella distributor.

[0028] In a second aspect, the present invention provides a solvent removal apparatus for a polymer solution, the solvent removal apparatus comprising:

[0029] It includes a polymer solution inlet, a preheating end, a polymer desolventizing and separation device as described in the first aspect, and a flash evaporation device connected in sequence.

[0030] The polymer outlet of the polymer desolventizing and separating equipment is connected to the flash evaporation equipment.

[0031] As a preferred technical solution of the present invention, the preheating end includes: heat exchange preheating equipment and / or heating preheating equipment.

[0032] Thirdly, the present invention provides a solvent removal method for a polymer solution, the solvent removal method comprising:

[0033] The polymer solution was preheated, separated, and flash-evaporated sequentially to obtain the polymer.

[0034] The separation is carried out using the polymer desolventizing separation equipment as described in the first aspect.

[0035] As a preferred embodiment of the present invention, the polymer solution contains 40-50% polymer by mass.

[0036] Preferably, the feed pressure of the polymer solution is 2-6 MPaG.

[0037] As a preferred embodiment of the present invention, the temperature of the preheated material is 180-260℃.

[0038] Preferably, the preheating method includes heat exchange and / or heating.

[0039] As a preferred technical solution of the present invention, the polymer desolventizing separation equipment in the separation process is operated with full liquid, and the residence time of the material in the internal phase separation zone is 10-30 minutes.

[0040] Preferably, the operating pressure of the flash evaporation is -50~30 kPaG.

[0041] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0042] (1) When the separation device provided by the present invention performs solvent separation, the energy consumption is significantly reduced: the phase separation of the separation equipment increases the polymer content from 40-50% to 60-70%, thereby reducing the amount of solvent evaporation entering the flash evaporation equipment and significantly reducing the total energy consumption.

[0043] (2) The separation device provided by the present invention has a small investment in equipment. Compared with the traditional multi-stage heating and flash evaporation (usually three-stage heating + three-stage flash evaporation), the present invention can obtain polymers with high solid content by only one stage of heating, one stage of separation and one stage of flash evaporation.

[0044] (3) The separation method provided by the present invention has a simple process and a shorter process, which reduces the residence time of polymer in the system and avoids the problem caused by the poor flowability of high viscosity polymer. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the polymer desolventizing and separating equipment provided in an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram showing the distribution of the arc-shaped guide plates in the polymer desolventizing separation device according to an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the orifice plate in the polymer desolventizing separation device according to an embodiment of the present invention;

[0048] Figure 4 This is a schematic diagram of the polymer desolventizing and separating apparatus provided in an embodiment of the present invention;

[0049] Figure 5 This is a schematic diagram of the device used in Comparative Example 1 of the present invention;

[0050] Figure 6 This is a schematic diagram of the device used in Comparative Example 2 of the present invention;

[0051] Figure 7 This is a schematic diagram of the device used in Comparative Example 3 of the present invention;

[0052] Figure 8 This is a schematic diagram of the device used in Comparative Example 4 of the present invention.

[0053] In the diagram: 100 - Polymer desolventizing and separation equipment, 110 - Polymer solution inlet, 120 - Annular baffle area, 130 - Cyclone umbrella distributor, 131 - Arc-shaped guide plate, α - Arc angle, 140 - Orifice plate area, 141 - Orifice plate, 142 - Orifice, 150 - Polymer outlet, 160 - Solvent outlet, 200 - Preheating end, 300 - Flash evaporation equipment;

[0054] I - Polymer solution inlet, II - Solvent vapor outlet.

[0055] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0056] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0057] Currently, polymer solvent removal often employs a "devouring + extrusion" process, requiring multi-stage heating followed by flash evaporation (typically three stages of heating + three stages of flash evaporation), and finally solvent removal in a vacuum extruder to meet product requirements. However, this process is complex, energy-intensive, and has low solvent removal efficiency. Therefore, this invention optimizes the separation equipment by utilizing a specifically designed separation device to increase the polymer content from 40-50% to 60-70%, thereby improving the final solvent removal effect, as detailed below:

[0058] I. This embodiment provides a polymer desolventizing and separation device, which includes:

[0059] The polymer solution inlet 110, annular baffle zone 120, swirl-type umbrella distributor 130, orifice plate zone 140, and polymer outlet 150 are connected in sequence, as follows: Figure 1 As shown;

[0060] The annular baffle area 120 is provided with a solvent outlet 160.

[0061] The inner diameter of the annular baffle area 120 is 2 / 3 to 3 / 4 of the inner diameter of the polymer desolventizing and separating device 100. For example, it can be 2 / 3, 41 / 60, 21 / 30, 43 / 60, 22 / 30 or 3 / 4, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0062] The height of the annular baffle area 120 is 100-500mm, for example, it can be 100mm, 140mm, 180mm, 220mm, 260mm, 300mm, 340mm, 380mm, 420mm, 460mm or 500mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0063] The swirl-type umbrella-shaped distributor 130 includes a conical body with a cone angle of 60-90°, such as 60°, 63°, 66°, 69°, 72°, 75°, 78°, 81°, 84°, 87° or 90°, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0064] The surface of the swirling umbrella-shaped distributor 130 is distributed with 6-24 arc-shaped guide plates 131, such as... Figure 2 As shown, the number of pieces can be 6, 8, 10, 12, 14, 16, 18, 20, 22, or 24, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0065] In this invention, the helix angle of the swirl umbrella-shaped distributor 130 is 15-60°. When the helix angle is small (e.g., <15°), the fluid mainly moves axially, the rotation is more regular, the vortex is not easily broken, and the swirl is more stable. When the helix angle is too large (e.g., >60°), the tangential velocity is too large and it is easy to cause turbulent disturbances. The swirl will become disordered and even secondary vortices will appear. When the helix angle increases, the friction area and relative velocity between the fluid and the wall increase, and the energy loss (e.g., pressure loss, resistance) will increase.

[0066] The arc angle α of the arc-shaped guide plate 131 is 15-60°, for example, it can be 15°, 19.5°, 24°, 28.5°, 33°, 37.5°, 42°, 46.5°, 51°, 55.5° or 60°, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0067] The distance between the end of the cyclone umbrella distributor 130 and the inner wall of the polymer desolventizing and separating device 100 is 100-500mm, for example, it can be 100mm, 140mm, 180mm, 220mm, 260mm, 300mm, 340mm, 380mm, 420mm, 460mm or 500mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0068] In this invention, the swirl-type umbrella distributor 130 has a conical, swirl-type structure. Its conical surface forms a "buffer-guide" effect on the high-speed medium. The kinetic energy is absorbed by the conical surface, and the flow velocity is significantly reduced. This avoids the high-speed fluid directly impacting the stationary liquid in the tank to form violent turbulence. Turbulence will destroy the already formed phase interface and hinder phase separation.

[0069] In this invention, the design of the swirl-type umbrella distributor 130 allows the polymer solution to "spread out" along the conical surface to form an annular diffusion flow. The dispersed medium flows towards the tank wall at a lower speed, initially eliminating the "jet effect" of the feed and creating a low-disturbance environment for subsequent phase separation.

[0070] Wherein, the perforated plate region 140 includes at least one perforated plate 141, such as Figure 3 As shown, multiple polymer desolventizing and separation devices are arranged at certain intervals along the axial direction.

[0071] The perforated plate 141 is a perforated plate with holes 142 having a diameter of 20-40mm. For example, it can be 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm, 34mm, 36mm, 38mm or 40mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0072] The spacing between the holes 142 on the perforated plate 141 is 2-3 times the hole diameter, for example, it can be 2 times, 2.1 times, 2.2 times, 2.3 times, 2.4 times, 2.5 times, 2.6 times, 2.7 times, 2.8 times, 2.9 times or 3 times, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0073] The diameter of the orifice plate 141 is 90-95% of the inner diameter of the polymer desolventizing and separating equipment 100. For example, it can be 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, or 95%, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0074] The spacing between adjacent perforated plates 141 is 0.5-1.5m, for example, it can be 0.5m, 0.6m, 0.7m, 0.8m, 0.9m, 1m, 1.1m, 1.2m, 1.3m, 1.4m or 1.5m, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0075] The orifice plate area 140 is located 0.5-1.5m below the swirl umbrella-shaped distributor 130, for example, it can be 0.5m, 0.6m, 0.7m, 0.8m, 0.9m, 1m, 1.1m, 1.2m, 1.3m, 1.4m or 1.5m, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0076] In this invention, the design of the orifice plate region 140 serves two purposes. First, it ensures a uniform flow field. The dispersed medium may exhibit localized velocity inconsistencies (e.g., slightly higher velocities near the tank wall). As the liquid passes through the orifice plate 141, it must pass through each hole 142 individually, forcibly transforming the annular diffusion flow into a uniform "columnar flow stream," ensuring a uniform velocity distribution of the medium entering the phase separation region. Second, it further decelerates the flow. The throttling effect of the orifice plate 141 further reduces the medium velocity, and the flow state changes from "diffusion flow" to "laminar-dominated slow flow," preventing the formation of phase interfaces due to localized turbulent disturbances.

[0077] In this invention, the polymer desolventizing and separating device 100 operates in a full-liquid state, and its internal medium phase separation process is as follows:

[0078] 1) The polymer solution is sprayed vertically downward from the feed port at the center of the top of the container. The initial flow rate is relatively fast, and it rushes towards the umbrella-shaped distributor below in a "column jet".

[0079] 2) The jet impacts the conical body of the umbrella-shaped distributor and is instantly dispersed into a "radial fan-shaped flow", and the polymer and solvent begin to separate initially.

[0080] 3) Most of the dispersed material slides down the container wall along the arc-shaped guide plate 131, forming a spiral downward mainstream, while the remaining material diffuses radially.

[0081] 4) The material flowing down the wall reaches the perforated plate 141 below and is further dispersed as it passes through the holes 142, eliminating turbulence and forming a uniform "slowly descending flow". At this time, the polymer continues to sink due to its high density, while the solvent slowly floats due to its low density.

[0082] 5) The descending polymer gradually accumulates at the bottom of the container, forming a "bottom polymer dense phase zone"; the rising solvent passes through the rectifier plate and flows upward along the gap between the container wall and the central descending flow, forming a "middle solvent rising zone", and the interface with the polymer gradually becomes clear (the interface is horizontal and slowly moves upward).

[0083] 6) The solvent floats to the top of the container, bypasses the upper baffle, and overflows to the solvent outlet 160. The baffle increases the upward path of the solvent and forms an annular flow channel inside the baffle, which can further prevent the polymer phase from being carried to the solvent outlet 160.

[0084] 7) Both solvent and polymer are discharged smoothly, and the phase interface remains stable at this time.

[0085] The swirl-type umbrella distributor 130 converts the "direct impulse energy" of the feed into "wall-adhering downward flow" through "impact dispersion → flow guide plate guidance → rectification and flow equalization", reserving a sufficient path for the solvent to float upward; the channel formed by the annular baffle also forces the solvent to overflow in an annular manner, further reducing the possibility of polymer entrainment.

[0086] In this invention, the polymer desolventizing and separation equipment 100 is a vertical separation equipment whose phase separation process is based on the synergistic effect of "flow regulation + gravity sedimentation". By optimizing the flow state through internal components, efficient separation is achieved by utilizing the density difference between the two phases.

[0087] II. This embodiment provides a solvent removal device for a polymer solution, such as... Figure 4 As shown, the solvent removal device includes:

[0088] It includes a polymer solution inlet I, a preheating end 200, a polymer desolventizing and separating device 100, and a flash evaporation device 300 connected in sequence;

[0089] The polymer outlet 150 of the polymer desolventizing and separating device 100 is connected to the flash evaporator 300.

[0090] The preheating end 200 includes: heat exchange preheating equipment and / or heating preheating equipment.

[0091] In this invention, the heat exchange preheating equipment can be selected from commonly used heat exchangers in the field, such as heat exchangers.

[0092] In this invention, the heating and preheating equipment can be selected as a thermocouple, microwave heating, or other heating equipment.

[0093] In this invention, the inner walls of the polymer solvent removal separation equipment 100 and the solvent removal device can be polished to prevent media accumulation, the formation of dead zones, and blockage of equipment and pipelines. The polishing degree should meet the requirement that the surface roughness Ra ≤ 0.2 μm.

[0094] In this invention, the flash evaporation equipment 300 is equipped with a solvent vapor outlet II.

[0095] III. This embodiment provides a solvent removal method for a polymer solution, the solvent removal method comprising:

[0096] The polymer solution was preheated, separated, and flash-evaporated sequentially to obtain the polymer.

[0097] The polymer solution contains 40-50% by mass, for example, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0098] The feed pressure of the polymer solution is 2-6 MPaG, for example, it can be 2 MPaG, 2.4 MPaG, 2.8 MPaG, 3.2 MPaG, 3.6 MPaG, 4 MPaG, 4.4 MPaG, 4.8 MPaG, 5.2 MPaG, 5.6 MPaG or 6 MPaG, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0099] The temperature of the preheated material is 180-260℃, for example, it can be 180℃, 188℃, 196℃, 204℃, 212℃, 220℃, 228℃, 236℃, 244℃, 252℃ or 260℃, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0100] The preheating method includes heat exchange and / or heating.

[0101] The separation is carried out using a polymer desolventizing separation device.

[0102] The polymer desolventizing separation equipment in the separation process is operated with full liquid, and the residence time of the material in the internal phase separation zone is 10-30 min, for example, it can be 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min or 30 min, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0103] In this invention, the phase separation region refers to the area formed by the annular baffle region 120, the swirling umbrella-shaped distributor 130, and the orifice plate region 140.

[0104] The operating pressure of the flash evaporation is -50~30kPaG, for example, it can be -50kPaG, -40kPaG, -30kPaG, -20kPaG, -10kPaG, 0kPaG, 10kPaG, 15kPaG, 20kPaG, 25kPaG or 30kPaG, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0105] IV. To illustrate the solvent separation effect achievable by the polymer desolventizing and separating equipment provided by this invention, the following practical example is used for explanation:

[0106] Example 1

[0107] This embodiment provides a method for solvent removal from polymers, and the equipment parameters of the removal apparatus are as follows:

[0108] Heat exchanger: shell side heating, heat transfer oil as the heat medium, tube side polished to a surface roughness of 0.2μm;

[0109] Polymer desolventizing and separation equipment: 1.5m in diameter, 4.0m in height, with an annular baffle having an inner diameter of 1m and a height of 300mm; a cyclone-type (30° spiral angle) umbrella-shaped distributor with a cone angle of 60°, equipped with 8 guide plates with 45° arc angles, and a distance of 200mm between the end of the distributor and the inner wall of the container; one orifice plate in the orifice plate area, with a diameter of 1.4m, orifice diameter of 20mm, and orifice spacing of 40mm, horizontally installed 0.8m below the umbrella-shaped distributor; full liquid operation, with the inner wall of the tank and the surface of the internal parts polished to a surface roughness of 0.2μm;

[0110] Flash evaporation equipment: 1.0m in diameter, 2.5m in height, operating pressure of 10kPaG, and the inner wall of the tank is polished to a surface roughness of 0.2μm.

[0111] The above process was used to treat the cyclic olefin copolymer recovery solution, with an initial solid content of 45%, using a mixed solution of cyclohexane and n-hexane as the solvent, at a pressure of 5 MPaG. The steps are as follows:

[0112] (1) Preheating: The cyclic olefin copolymer recovery solution is heated to 210°C by a heat exchanger, and the feed pressure is 5 MPaG;

[0113] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing and separation equipment and stays in the phase separation zone for 20 minutes. After phase separation, the light phase is collected through the overflow port. The polymer content in the top light phase is 0.02%, and the content of the bottom heavy phase cyclic olefin copolymer is 66%.

[0114] (3) Reduced pressure flash evaporation: The heavy phase is fed into the flash evaporation equipment and solvent flash evaporation is carried out at 210°C. The bottom is a melt with a cyclic olefin copolymer concentration of 96%.

[0115] Example 2

[0116] The only difference from Example 1 is that the spiral angle of the cyclone umbrella distributor is 15°, with 10 guide plates at 36° arc angles, and the distance between the distributor end and the inner wall of the container is 150 mm. Otherwise, the process is the same as in Example 1, treating the POE recovery solution. The initial POE content is 45%, a mixed solution of cyclohexane and ethanol, at a pressure of 5 MPaG. The method steps are as follows:

[0117] (1) Preheating: The POE solution is heated to 200°C by a heat exchanger and the feed pressure is 5 MPaG;

[0118] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing and separation equipment and stays in the phase separation zone for 20 minutes. After phase separation, the light phase is collected through the overflow port. The polymer content in the top light phase is 0.03%, and the POE content in the bottom heavy phase is 65%.

[0119] (3) Reduced pressure flash evaporation: The heavy phase is fed into the flash evaporation equipment and the solvent is flashed at 200°C to obtain a melt with a POE concentration of 95% at the bottom.

[0120] Example 3

[0121] The only difference from Example 1 is that the orifice plate has a diameter of 1.4 m, an orifice diameter of 30 mm, an orifice spacing of 60 mm, and is horizontally installed 1 m below the umbrella-shaped distributor. The operating pressure of the flash evaporator is -10 kPaG. The rest of the process is the same as in Example 1, treating the PC recovery solution. The initial PC content is 50%, the solvent is a mixture of chloroform and methanol, and the pressure is 6 MPaG. The method steps are as follows:

[0122] (1) Preheating: The PC solution is heated to 230°C by a heat exchanger and the feed pressure is 6 MPaG;

[0123] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing separation device and stays in the phase separation zone for 18 minutes. The polymer content in the light phase at the top is 0.03%, and the PC content in the heavy phase is 68%.

[0124] (3) Reduced pressure flash evaporation: The heavy phase is fed into the flash evaporation equipment and the solvent is flashed at 230°C to obtain a melt with a PC concentration of 95% at the bottom.

[0125] Example 4

[0126] The only difference from Example 1 is that the spiral angle of the cyclone umbrella distributor is 60°, with 12 guide plates at 30° arc angles, and the operating pressure of the flash evaporator is -15 kPaG. The rest of the process is the same as in Example 1, treating the PMMA recovery solution. The initial PMMA content is 50%, the solvent is a mixture of tetrahydrofuran and methanol, and the pressure is 4 MPaG. The method steps are as follows:

[0127] (1) Preheating: The PMMA solution is heated to 200°C via a heat exchanger, and the feed pressure is 4 MPaG;

[0128] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing separation device and stays in the phase separation zone for 16 minutes. The polymer content in the light phase at the top is 0.04%, and the PMMA content in the heavy phase is 67%.

[0129] (3) Reduced pressure flash evaporation: The heavy phase is fed into the flash evaporation equipment and the solvent is flashed at 200°C to obtain a melt with PMMA concentration of 95% at the bottom.

[0130] Example 5

[0131] The process is the same as in Example 1, treating the PP recovery solution. The initial PP content is 50%, the solvent is a mixed solution of cyclohexane and ethanol, and the pressure is 5 MPaG. The method steps are as follows:

[0132] (1) Preheating: The PP solution is heated to 180°C by a heat exchanger and the feed pressure is 5 MPaG;

[0133] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing separation device and stays in the phase separation zone for 20 minutes. The polymer content in the light phase at the top is 0.04%, and the PP content in the heavy phase is 70%.

[0134] (3) Reduced pressure flash evaporation: The heavy phase is fed into the flash evaporation equipment and the solvent is flashed at 180°C to obtain a melt with a PP concentration of 96% at the bottom.

[0135] Comparative Example 1

[0136] Using the same medium as in Example 1, a multi-stage heating and flash evaporation process was employed, consisting of a three-stage heating + three-stage flash evaporation process. The apparatus used was as follows: Figure 5As shown.

[0137] (1) First-stage heating + flash evaporation: The cyclic olefin copolymer recovery solution is heated to 180°C by the first-stage heat exchanger and then enters the first-stage flash evaporation equipment. The operating pressure of the first-stage flash evaporation equipment is 30 kPaG. Part of the solvent is flashed, and a polymer solution with a cyclic olefin copolymer concentration of 60% is obtained at the bottom.

[0138] (2) Secondary heating + flash evaporation: The polymer solution at the bottom of the primary flash evaporator is heated to 195°C by the secondary heat exchanger and then enters the secondary flash evaporator. The operating pressure of the secondary flash evaporator is 20 kPaG. Part of the solvent is flashed, and a polymer solution with a cyclic olefin copolymer concentration of 80% is obtained at the bottom.

[0139] (3) Three-stage heating + flash evaporation: The polymer solution at the bottom of the two-stage flash evaporation equipment is heated to 210°C by the three-stage heat exchanger and then enters the three-stage flash evaporation equipment. The operating pressure of the three-stage flash evaporation equipment is 10 kPaG. Part of the solvent is flashed, and a melt with a cyclic olefin copolymer concentration of 96% is obtained at the bottom.

[0140] Comparative Example 2

[0141] Using the same media as in Example 1, the liquid-liquid separation process of the homogeneous polymer solution described in patent CN113164898A was employed, and the apparatus used was as follows: Figure 6 As shown.

[0142] (1) Preheating: The cyclic olefin copolymer recovery solution is heated to 210°C by a heat exchanger, and the feed pressure is 5 MPaG;

[0143] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing and separating equipment (without internal components, specifically without the annular baffle zone, cyclone umbrella distributor, and orifice plate zone of this invention), stays in the phase separation zone for 20 minutes, and after phase separation, the light phase is collected through the overflow port, and the bottom heavy phase contains 47% cyclic olefin copolymer;

[0144] (3) First-stage vacuum flash evaporation: The heavy phase is fed into the first-stage flash evaporation equipment at an operating pressure of 10 kPaG and solvent flash evaporation is carried out at 210°C. The bottom of the melt has a cyclic olefin copolymer concentration of 76%.

[0145] (4) Second-stage reduced pressure flash evaporation: The medium at the bottom of the first-stage flash evaporator enters the second-stage flash evaporator at an operating pressure of 2 kPaG. Solvent flash evaporation is carried out at 210°C, and a melt with a cyclic olefin copolymer concentration of 96% is obtained at the bottom.

[0146] Comparative Example 3

[0147] The process is the same as in Example 1, except that the cyclone umbrella distributor in the polymer desolventizing and separating equipment is omitted, and the device used is as follows: Figure 7 As shown, the method steps are as follows:

[0148] (1) Preheating: The cyclic olefin copolymer recovery solution is heated to 210°C by a heat exchanger, and the feed pressure is 5 MPaG;

[0149] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing and separation equipment and stays in the phase separation zone for about 20 minutes. After phase separation, the light phase is collected through the overflow port. The polymer content in the top light phase is 0.02%, and the content of the bottom heavy phase cyclic olefin copolymer is 56%.

[0150] (3) Reduced pressure flash evaporation: The heavy phase is fed into the primary flash evaporator and subjected to solvent flash evaporation at 210°C, resulting in a melt with a cyclic olefin copolymer concentration of 80% at the bottom. This melt is then fed into the secondary flash evaporator, where the operating pressure is reduced to 2 kPaG and solvent flash evaporation is performed at 210°C, resulting in a melt with a cyclic olefin copolymer concentration of 96% at the bottom.

[0151] Comparative Example 4

[0152] The process is the same as in Example 1, except that the orifice plate in the polymer desolventizing separation device is omitted, and the device used is as follows: Figure 8 The steps of the method shown are as follows:

[0153] (1) Preheating: The cyclic olefin copolymer recovery solution is heated to 210°C by a heat exchanger, and the feed pressure is 5 MPaG;

[0154] (2) Liquid-liquid phase separation: The solution enters the polymer desolventizing and separation equipment and stays in the phase separation zone for 20 minutes. After phase separation, the light phase is collected through the overflow port. The polymer content in the top light phase is 0.02%, and the content of the bottom heavy phase cyclic olefin copolymer is 54%.

[0155] (3) Reduced pressure flash evaporation: The heavy phase is fed into the first-stage flash evaporator and subjected to solvent flash evaporation at 210°C, resulting in a melt with a cyclic olefin copolymer concentration of 80% at the bottom. This melt is then fed into the second-stage flash evaporator, where the operating pressure is reduced to 2 kPaG and a large amount of solvent is flashed at 210°C, resulting in a melt with a cyclic olefin copolymer concentration of 96% at the bottom.

[0156] Example 6

[0157] The only difference from Example 1 is that the cone angle of the cone-shaped body is 10°.

[0158] Example 7

[0159] The only difference from Example 1 is that the cone angle of the cone-shaped body is 100°.

[0160] Example 8

[0161] The only difference from Example 1 is that the arc angle of the arc-shaped guide plate is 10°.

[0162] Example 9

[0163] The only difference from Example 1 is that the arc angle of the arc-shaped guide plate is 80°.

[0164] The following is a comparison of the relative energy consumption of Example 1 and Comparative Examples 1-4, namely Examples 6-9. The relative energy consumption is based on the actual energy consumption of Example 1 (set to a relative energy consumption of 1), and the ratio is calculated by "actual energy consumption of the target object ÷ actual energy consumption of Example 1", as shown in Table 1 below.

[0165] Table 1

[0166]

[0167] In summary, the method of this invention clearly achieves efficient and low-energy-consumption devolvation of polymers. Simultaneously, the process control is simple; the polymer desolventizing separation equipment increases the polymer content from 40-50% to 60-70% through phase separation, reducing solvent evaporation in the flash evaporation equipment. Compared to the traditional multi-stage heating flash evaporation process, the total energy consumption is significantly reduced. Furthermore, a comparison of Example 1 with the liquid-liquid separation process (without internal components) of the homogeneous polymer solution in patent number CN113164898A (Comparative Example 2) reveals that the liquid-liquid separation tank of this invention can significantly increase the solid content in the polymer solution, while the solid content at the bottom of the liquid-liquid separation tank in the comparative patent shows no significant change.

[0168] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0169] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0170] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A polymer desolventizing and separation device, characterized in that, The polymer desolventizing and separation equipment includes: The polymer solution inlet, horizontal annular baffle zone, swirling umbrella distributor, orifice plate zone and polymer outlet are connected sequentially from top to bottom. The sidewall of the horizontal annular baffle area is provided with an overflow solvent outlet; The swirl-type umbrella-shaped distributor includes: a conical body with a cone angle of 60-90°; 6-24 arc-shaped guide plates are distributed on the surface of the swirl-type umbrella-shaped distributor; the arc angle of the arc-shaped guide plates is 15-60°; The orifice plate area includes at least one orifice plate; the orifice plate is an orifice plate with holes having a diameter of 20-40 mm; the spacing between the holes on the orifice plate is 2-3 times the hole diameter; the diameter of the orifice plate is 90-95% of the inner diameter of the polymer desolventizing separation equipment; the spacing between adjacent orifice plates is 0.5-1.5 m.

2. The polymer desolventizing and separating equipment as described in claim 1, characterized in that, The inner diameter of the annular baffle area is 2 / 3 to 3 / 4 of the inner diameter of the polymer desolventizing and separating equipment; The height of the annular baffle area is 100-500mm.

3. The polymer desolventizing and separation equipment as described in claim 1, characterized in that, The swirl-type umbrella-shaped distributor includes: a conical body with a cone angle of 60-90°; The surface of the swirl umbrella-shaped distributor is distributed with 6-24 arc-shaped guide plates; The arc angle of the arc-shaped guide vane is 15-60°; The distance between the end of the cyclone umbrella distributor and the inner wall of the polymer desolventizing and separating equipment is 100-500 mm.

4. The polymer desolventizing and separating equipment as described in claim 1, characterized in that, The perforated plate area includes at least one perforated plate; The perforated plate is a perforated plate with holes having a diameter of 20-40mm; The spacing between the holes on the perforated plate is 2-3 times the hole diameter; The diameter of the orifice plate is 90-95% of the inner diameter of the polymer desolventizing and separating equipment; The spacing between adjacent perforated plates is 0.5-1.5m; The orifice plate area is located 0.5-1.5m below the swirl-type umbrella distributor.

5. A solvent removal device for a polymer solution, characterized in that, The solvent removal device includes: It includes a polymer solution inlet, a preheating end, a polymer desolventizing and separating device as described in any one of claims 1-4, and a flash evaporation device connected in sequence. The polymer outlet of the polymer desolventizing and separating equipment is connected to the flash evaporation equipment.

6. The solvent removal apparatus as described in claim 5, characterized in that, The preheating end includes: heat exchange preheating equipment and / or heating preheating equipment.

7. A method for solvent removal from a polymer solution, characterized in that, The solvent removal method includes: The polymer solution was preheated, separated, and flash-evaporated sequentially to obtain the polymer. The separation is carried out using the polymer desolventizing separation equipment as described in any one of claims 1-4.

8. The solvent removal method as described in claim 7, characterized in that, The polymer solution contains 40-50% polymer by mass. The feed pressure of the polymer solution is 2-6 MPaG.

9. The solvent removal method as described in claim 7, characterized in that, The temperature of the preheated material is 180-260℃; The preheating methods include heat exchange and / or heating.

10. The solvent removal method as described in claim 7, characterized in that, The polymer desolventizing separation equipment in the separation process is operated with full liquid, and the residence time of the material in the internal phase separation zone is 10-30 minutes. The operating pressure of the flash evaporation is -50~30 kPaG.

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