Polymer solvent removal separation equipment, solvent removal device and solvent removal method

Abstract

The invention relates to polymer desolventizing separation equipment, a solvent removal device and a solvent removal method, in particular to the technical field of polymer recovery, the polymer desolventizing separation equipment comprises a polymer solution inlet end, an annular baffle area, a spiral-flow type umbrella-shaped distributor, a pore plate area and a polymer outlet end which are communicated in sequence; a solvent outlet is formed in the annular baffle plate area. According to the polymer desolventizing agent separation equipment provided by the invention, the specific spiral-flow type umbrella-shaped distributor is matched with the pore plate flow equalizing assembly, during working, a polymer solution enters the separation equipment after being heated and is converted into a spiral-flow wall-attached flow through the spiral-flow type umbrella-shaped distributor, and the spiral flow generates centrifugal acceleration and forms a synergistic separation force with gravity; and then a spiral columnar laminar flow beam is formed through the pore plate flow equalizing assembly, efficient phase splitting is achieved in a phase splitting area in a full liquid state, finally, a top light phase is recycled, and the content of a bottom heavy phase polymer is increased to 60%-70%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polymer recovery, in particular to a polymer desolventizing separation device, a solvent removal device and a solvent removal method, and especially to a solvent separation device, a solvent removal device and a solvent removal method for removing solvent from a polymer solution. BACKGROUND

[0002] Flash devolatilization, as a basic separation technology in the chemical industry, is widely used in polymer synthesis, polymer recovery, environmental treatment and other scenarios.

[0003] In a common solution polymerization industrial process device, the most common devolatilization method for a polymer homogeneous solution is to evaporate the solution by heating. Because the molecular weight of the polymer and the solvent is very different, the polymer will produce a swelling effect in the solvent, and the high-concentration polymer solution has high viscosity and poor flowability, resulting in difficulty in heat conduction and mass transfer, so the higher the concentration of the polymer, the more difficult it is to separate. Similarly, in the field of polymer recovery, similar problems also exist.

[0004] In the current solvent method polymer recovery process, the broken particles are dissolved in the solvent, and after filtration and precipitation, a polymer solution with a solid content of 40-50% is obtained, and part of the solvent also swells in the polymer, making it difficult to remove.

[0005] In order to overcome the flowability problem of the polymer in the devolatilization process and the problem that the higher the concentration of the polymer, the more difficult it is to separate, a "devolatilization + extrusion" process is often used, that is, multiple heating and then flash evaporation (usually three-stage heating + three-stage flash evaporation) is required, and finally the solvent is removed to the product requirement in a vacuum extruder. Due to this process, the devolatilization process is complex and requires high energy consumption.

[0006] US5599885A discloses a method for preparing a polyolefin, and a liquid-liquid separation process is mentioned in the preparation process. The polymer solution containing the obtained polyolefin obtained from the polymerization process is sent to a separation zone maintained at a temperature not lower than the upper cloud point of the polymer solution to separate the polymer solution into a lower phase portion containing a high concentration of polyolefin and an upper phase portion, thereby recovering the polyolefin from the lower phase portion of the separation zone, and recycling at least a portion of the upper phase portion to the polymerization zone. When maintained at a temperature lower than the upper cloud point, the obtained polymer solution is a homogeneous liquid phase, but when maintained at a temperature not lower than the upper cloud point, it is separated into a concentrated phase and a dilute phase. Generally, the higher the temperature of the polymer solution not lower than the upper cloud point, the higher the copolymer concentration in the concentrated phase, and conversely, the lower the copolymer concentration in the dilute phase. In addition, the greater the concentration difference between the two phases, the more efficient the phase separation, so the post-treatment of the phases that can be easily separated can be easily carried out.

[0007] CN113164898A discloses a solution polymerization method, and it is mentioned in the scheme that the polymer solution can exhibit a lower critical solution temperature (LCST) phenomenon. Thus, the homogeneous polymer solution will separate into a polymer-rich liquid phase and a solvent-rich phase above a certain temperature. The temperature is a function of the type of solvent, the composition of the polymer stream, and the pressure. Any of these variables can be manipulated to cause liquid-liquid separation, which employs a process of warming, depressurization, and in a liquid-liquid separator, increases the polymer solids content to 20-24%.

[0008] The liquid-liquid separation method mentioned in the above prior art has very small heat load, and in particular, compared with the evaporation of an equal amount of solvent, a large amount of energy consumption is saved. However, this method is suitable for homogeneous solution after solution polymerization reaction, and phase separation is carried out by adjusting the temperature to be higher than the upper cloud point. It is not suitable for polymer recovery process, and in the solvent recovery process, after the broken particles are dissolved, the polymer solution with a solids content of 40-50% is a solid-liquid two-phase at room temperature. As the temperature rises, the solid polymer changes into a melt, and is obviously layered with the solvent. The polymer solution obtained by the solvent recovery process is obviously different from the homogeneous solution after the solution polymerization reaction.

[0009] In summary, there are still defects of poor solvent removal effect and high energy consumption when the polymer solution is subjected to solvent removal. SUMMARY

[0010] In view of the problems in the prior art, the purpose of the present application is to provide a polymer desolventizing and separating device, a solvent removal device and a solvent removal method, so as to solve the defects of poor solvent removal effect and high energy consumption when the polymer solution is subjected to solvent removal.

[0011] In order to achieve this purpose, the technical scheme adopted by the present application is as follows:

[0012] In a first aspect, the present application provides a polymer desolventizing and separating device, which comprises:

[0013] a polymer solution inlet end, an annular baffle zone, a cyclone umbrella distributor, a perforated plate zone and a polymer outlet end connected in sequence;

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

[0015] The polymer desolventizing separation device provided by the application is characterized in that: a specific cyclone umbrella distributor and a hole plate flow uniformizing assembly are arranged in cooperation, when working, the polymer solution is heated and then enters the separation device, is converted into a cyclone wall-adhering flow by the cyclone umbrella distributor, the cyclone generates a centrifugal acceleration, and a synergistic separation force is formed with the gravity, and then a spiral columnar laminar flow beam is formed by the hole plate flow uniformizing assembly, high-efficiency phase separation is realized in the full-liquid phase separation area, and finally the top light phase is recycled and used, and the polymer content of the bottom heavy phase is increased to 60-70%.

[0016] As a preferred technical solution of the application, the inner diameter of the annular baffle area is 2 / 3-3 / 4 of the inner diameter of the polymer desolventizing separation device.

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

[0018] As a preferred technical solution of the application, the cyclone umbrella distributor comprises a conical main body with a conical angle of 60-90°.

[0019] Preferably, the surface of the cyclone umbrella distributor is distributed with 6-24 arc-shaped flow guides.

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

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

[0022] As a preferred technical solution of the application, the hole plate area comprises at least one hole plate.

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

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

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

[0026] Preferably, the distance between adjacent hole plates is 0.5-1.5 m.

[0027] Preferably, the hole plate area is located 0.5-1.5 m below the cyclone umbrella distributor.

[0028] In the second aspect, the application provides a solvent removal device for a polymer solution, and the solvent removal device comprises:

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

[0030] The polymer outlet end of the polymer desolventizing separation device is connected with a flash device.

[0031] As a preferred technical solution of the present application, the preheating end comprises a heat exchange preheating device and / or a heating preheating device.

[0032] In a third aspect, the present application provides a solvent removal method of a polymer solution, which comprises:

[0033] The polymer solution is sequentially preheated, separated and flashed to obtain a polymer.

[0034] The separation is performed by using the polymer desolventizing separation device according to the first aspect.

[0035] As a preferred technical solution of the present application, the mass percentage of the polymer in the polymer solution is 40-50%.

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

[0037] As a preferred technical solution of the present application, the temperature of the preheated material is 180-260℃.

[0038] Preferably, the preheating mode comprises heat exchange and / or heating.

[0039] As a preferred technical solution of the present application, the polymer desolventizing separation device in the separation is full-liquid operated, and the residence time of the material in the internal phase region is 10-30 min.

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

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] (1) The separation device provided by the present application can significantly reduce energy consumption when performing solvent separation: the separation device separates the polymer content from 40-50% to 60-70%, thereby reducing the solvent evaporation amount entering the flash device and significantly reducing the total energy consumption.

[0043] (2) The separation device provided by the present application has small equipment investment: compared with the traditional multi-stage heating and re-flashing (usually three-stage heating + three-stage flashing), the present application only uses one-stage heating, one-stage separation and one-stage flashing to obtain a polymer with high solid content.

[0044] (3) The separation method provided by the present application has a simple process: the process of the present application is shorter, which reduces the residence time of the polymer in the system and avoids the problems caused by poor flowability of high-viscosity polymers. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a schematic diagram of the polymer desolventization and separation device provided by the embodiment of the present application;

[0046] Figure 2 is a distribution schematic diagram of the arc-shaped guide plate in the polymer desolventization and separation device of the embodiment of the present application;

[0047] Figure 3 is a schematic diagram of the hole plate in the polymer desolventization and separation device of the embodiment of the present application;

[0048] Figure 4 is a schematic diagram of the polymer desolventization and separation device provided by the embodiment of the present application;

[0049] Figure 5 is a schematic diagram of the device used in the comparative example 1 of the present application;

[0050] Figure 6 is a schematic diagram of the device used in the comparative example 2 of the present application;

[0051] Figure 7 is a schematic diagram of the device used in the comparative example 3 of the present application;

[0052] Figure 8 is a schematic diagram of the device used in the comparative example 4 of the present application.

[0053] In the figure: 100-polymer desolventization and separation device, 110-polymer solution inlet end, 120-annular baffle area, 130-cyclone umbrella distributor, 131-arc-shaped guide plate, a-arc angle, 140-hole plate area, 141-hole plate, 142-hole, 150-polymer outlet end, 160-solvent outlet, 200-preheating end, 300-flash evaporation device;

[0054] I-polymer solution feeding end, II-solvent vapor outlet.

[0055] The present application will be further described in detail below. However, the following examples are only simple examples of the present application, and do not represent or limit the protection scope of the present application, and the protection scope of the present application is subject to the claims. DETAILED DESCRIPTION

[0056] In order to better illustrate the present application and facilitate the understanding of the technical solutions of the present application, the typical but non-limiting embodiments of the present application are as follows:

[0057] When the polymer solvent is removed at present, the "devolatilization + extrusion" process is often used, that is, multi-stage heating and then flash evaporation (usually three-stage heating + three-stage flash evaporation) is required, and finally the solvent is removed to the product requirement in a vacuum extruder, however, this process, the devolatilization process is complex, the energy consumption required for devolatilization is high, and the solvent removal efficiency is low, based on this, the present application optimizes the separation equipment, by using a specially designed separation equipment, the polymer content is increased from 40-50% to 60-70%, thereby improving the final solvent removal effect, as follows:

[0058] One, the embodiment provides a polymer desolventizing separation equipment, the polymer desolventizing separation equipment comprises:

[0059] The polymer solution inlet end 110, the annular baffle area 120, the cyclone umbrella distributor 130, the perforated plate area 140 and the polymer outlet end 150 are sequentially communicated, as shown in Figure 1 ;

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

[0061] Among them, the inner diameter of the annular baffle area 120 is 2 / 3-3 / 4 of the inner diameter of the polymer desolventizing separation equipment 100, for example, it can be 2 / 3, 41 / 60, 21 / 30, 43 / 60, 22 / 30 or 3 / 4, etc., but not limited to the listed values, other unlisted values within the range also meet the requirements.

[0062] Among them, 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, etc., but not limited to the listed values, other unlisted values within the range also meet the requirements.

[0063] Among them, the cyclone umbrella distributor 130 comprises a conical main body with a cone angle of 60-90°, for example, it can be 60°, 63°, 66°, 69°, 72°, 75°, 78°, 81°, 84°, 87° or 90°, etc., but not limited to the listed values, other unlisted values within the range also meet the requirements.

[0064] Among them, the surface of the cyclone umbrella distributor 130 is distributed with 6-24 arc guide plates 131, as shown in Figure 2 , for example, it can be 6, 8, 10, 12, 14, 16, 18, 20, 22 or 24, etc., but not limited to the listed values, other unlisted values within the range also meet the requirements.

[0065] In the present application, the helix angle of the cyclone umbrella distributor 130 is 15-60°. When the helix angle is small (e.g. < 15°), the fluid mainly moves in the axial direction, the rotation is more regular, the vortex is not easy to break, and the cyclone is more stable. When the helix angle is too large (e.g. > 60°), the tangential velocity is too large to easily cause turbulent disturbance, the cyclone becomes disordered, and even secondary vortex appears. When the helix angle increases, the friction area and relative velocity between the fluid and the wall surface increase, and the energy loss (such as pressure loss and resistance) will increase.

[0066] The arc angle a of the arc flow 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°, etc., but is not limited to the listed values, and other unlisted values within the range also meet the requirements.

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

[0068] In the present application, the cyclone umbrella distributor 130 is a conical and cyclone structure, and the conical surface forms a "buffer-flow guide" effect on the high-speed medium. The kinetic energy is absorbed by the conical surface, and the flow rate is significantly reduced. This avoids the direct impact of high-speed fluid on the stationary liquid in the tank, which forms a violent turbulent flow. The turbulent flow can destroy the formed phase interface and hinder the phase separation.

[0069] In the present application, the design of the cyclone umbrella distributor 130 makes the polymer solution spread along the conical surface to the four directions, forming a ring-shaped diffusion flow. The dispersed medium flows to the tank wall at a low speed, which preliminarily eliminates the "jet effect" of the feed, and creates a low disturbance environment for subsequent phase separation.

[0070] The hole plate area 140 includes at least one hole plate 141, as shown in the figure, multiple hole plates are arranged at a certain interval along the axial direction of the polymer desolvation separation device. Figure 3

[0071] The hole plate 141 is a hole plate with a hole diameter of 20-40mm, for example, it can be 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm, 34mm, 36mm, 38mm or 40mm, etc., but is not limited to the listed values, and other unlisted values within the range also meet the requirements.

[0072] ​The distance between the holes 142 on the hole plate 141 is 2-3 times the diameter of the holes, 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, etc., but not limited to the listed values, other unlisted values within the range are also required.

[0073] The diameter of the hole plate 141 is 90-95% of the inner diameter of the polymer desolventization and separation device 100, for example, it can be 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5% or 95%, etc., but not limited to the listed values, other unlisted values within the range are also required.

[0074] The distance between adjacent hole 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, etc., but not limited to the listed values, other unlisted values within the range are also required.

[0075] The hole plate area 140 is located 0.5-1.5m below the cyclone umbrella 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, etc., but not limited to the listed values, other unlisted values within the range are also required.

[0076] In the present application, the design of the hole plate area 140 can on the one hand distribute the flow field evenly, and the dispersed medium may have local flow rate unevenness (such as slightly higher flow rate near the tank wall), when passing through the hole plate 141 with holes, the liquid needs to pass through each hole 142, forcing the annular diffusion flow to be converted into uniform "columnar flow beam group", ensuring that the medium flow rate distribution entering the phase separation area is uniform. On the other hand, it is also to further slow down, the throttling effect of the hole plate 141 reduces the flow rate of the medium again, and the flow state is changed from "diffusion flow" to "mainly laminar flow", avoiding the disturbance of local turbulent flow to the phase interface that has begun to form.

[0077] In the present application, when the polymer desolventization and separation device 100 is working, it is full liquid operation, and the internal medium phase separation process is as follows:

[0078] 1) The polymer solution is sprayed vertically downward from the feed inlet at the center of the top of the container, with an initial high flow rate, and is "columnar jet" to the umbrella distributor below.

[0079] 2) The jet hits the conical body of the umbrella distributor and is instantaneously dispersed into "radial fan flow", and the polymer and solvent begin to separate.

[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 the present application, the heating preheating device can be selected as an electric heating couple, a microwave heating device, etc.

[0093] In the present application, the inner wall of each device and the inner wall of the pipeline in the polymer desolventizing separation device 100 and the solvent removing device can be polished to prevent the accumulation of medium, the formation of dead zones, and the blockage of the device and the pipeline, and the polishing degree should satisfy the surface roughness Ra≤0.2 μm.

[0094] In the present application, the flash evaporation device 300 is provided with a solvent vapor outlet II.

[0095] In a third embodiment, a solvent removing method for a polymer solution is provided, which comprises:

[0096] The polymer solution is sequentially preheated, separated, and flash evaporated to obtain a polymer.

[0097] The mass percentage of the polymer in the polymer solution is 40-50%, for example, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%, etc., but is not limited to the listed values, and other unlisted values in the range also meet the requirements.

[0098] The feeding pressure of the polymer solution is 2-6 MPaG, for example, 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, etc., but is not limited to the listed values, and other unlisted values in the range also meet the requirements.

[0099] The temperature of the preheated material is 180-260℃, for example, 180℃, 188℃, 196℃, 204℃, 212℃, 220℃, 228℃, 236℃, 244℃, 252℃, or 260℃, etc., but is not limited to the listed values, and other unlisted values in the range also meet the requirements.

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

[0101] The separation is performed by using a polymer desolventizing separation device.

[0102] The polymer desolventizing separation device is full-liquid operation, and the residence time of the material in the internal phase separation zone is 10-30 min, for example, 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min or 30 min, but is not limited to the listed values, and other values not listed in the range are also required.

[0103] In the present application, the phase separation zone refers to the area formed by the annular baffle zone 120, the cyclone umbrella distributor 130 and the perforated plate zone 140.

[0104] The operation pressure of the flash evaporation is -50-30 kPaG, for example, -50 kPaG, -40 kPaG, -30 kPaG, -20 kPaG, -10 kPaG, 0 kPaG, 10 kPaG, 15 kPaG, 20 kPaG, 25 kPaG or 30 kPaG, but is not limited to the listed values, and other values not listed in the range are also required.

[0105] Four, in order to illustrate the solvent separation effect that the polymer desolventizing separation device can achieve, the following actual examples are used for illustration, and the details are as follows:

[0106] Example 1

[0107] The present embodiment provides a method for removing solvent from a polymer, and the equipment parameters of the removal device are as follows:

[0108] The heat exchanger: the shell side is heated, the heat medium is heat conducting oil, and the tube side is polished to a surface roughness of 0.2 μm;

[0109] The polymer desolventizing separation device: the diameter is 1.5 m, the height is 4.0 m, the inner diameter of the annular baffle is 1 m, and the height is 300 mm; the conical angle of the cyclone (helix angle is 30°) umbrella distributor is 60°, 8 guide plates with an arc angle of 45° are arranged, the distance between the end of the distributor and the inner wall of the container is 200 mm; there is a perforated plate in the perforated plate zone, the diameter of the perforated plate is 1.4 m, the hole diameter of the holes on the perforated plate is 20 mm, the hole spacing is 40 mm, and the perforated plate is horizontally installed at a position 0.8 m below the umbrella distributor; full-liquid operation, the inner wall of the tank body and the surface of the inner part are polished to a surface roughness of 0.2 μm;

[0110] The flash evaporation device: the diameter is 1.0 m, the height is 2.5 m, the operation pressure is 10 kPaG, and the inner wall of the tank body is polished to a surface roughness of 0.2 μm.

[0111] The above process is used to treat a cycloolefin copolymer recovery solution, the initial solid content is 45%, the solvent is a mixed solution of cyclohexane and n-hexane, and the pressure is 5 MPaG. The method steps are as follows:

[0112] (1) Preheating: the recycle solution of cyclic olefin copolymer was heated to 210°C by heat exchanger, the feed pressure was 5 MPaG;

[0113] (2) Liquid-liquid phase separation: the solution entered the polymer desolventizing separation equipment, and stayed in the phase separation zone for 20 min. After phase separation, the light phase was collected through the overflow port. The entrained polymer content in the top light phase was 0.02%, and the bottom heavy phase contained 66% of cyclic olefin copolymer;

[0114] (3) Vacuum flash evaporation: the heavy phase was sent to the flash evaporation equipment, and solvent flash evaporation was carried out at 210°C. The bottom part obtained a melt with a cyclic olefin copolymer concentration of 96%.

[0115] Example 2

[0116] The difference from Example 1 was only that the spiral angle of the cyclone umbrella distributor was 15°, 10 pieces of 36° arc angle guide plates were provided, the distance between the distributor end and the inner wall of the container was 150 mm, and the process was the same as that of Example 1, which processed POE recycle solution. The initial POE content was 45%, and the mixed solution of cyclohexane and ethanol had a pressure of 5 MPaG. The method steps were as follows:

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

[0118] (2) Liquid-liquid phase separation: the solution entered the polymer desolventizing separation equipment, and stayed in the phase separation zone for 20 min. After phase separation, the light phase was collected through the overflow port. The entrained polymer content in the top light phase was 0.03%, and the bottom heavy phase contained 65% of POE;

[0119] (3) Vacuum flash evaporation: the heavy phase was sent to the flash evaporation equipment, and solvent flash evaporation was carried out at 200°C. The bottom part obtained a melt with a POE concentration of 95%.

[0120] Example 3

[0121] The difference from Example 1 was only that the orifice plate diameter was 1.4 m, the orifice diameter was 30 mm, the orifice spacing was 60 mm, the orifice plate was horizontally installed 1 m below the umbrella distributor, the operating pressure of the flash evaporation equipment was -10 kPaG, and the process was the same as that of Example 1, which processed PC recycle solution. The initial PC content was 50%, the solvent was a mixed solution of chloroform and methanol, and the pressure was 6 MPaG. The method steps were as follows:

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

[0123] (2) Liquid-liquid phase separation: the solution enters the polymer desolventizing separation equipment and stays in the phase separation zone for 18 min, the entrained polymer content in the top light phase is 0.03%, and the PC content in the heavy phase is 68%;

[0124] (3) Flash evaporation under reduced pressure: the heavy phase is sent into the flash evaporation equipment, and solvent flash evaporation is carried out at 230°C, and a melt with a PC concentration of 95% is obtained at the bottom.

[0125] Example 4

[0126] The difference from Example 1 is that the spiral angle of the cyclone umbrella distributor is 60°, 12 guide plates with an arc angle of 30° are arranged, the operating pressure of the flash evaporation equipment is -15 kPaG, and the other processes are the same as those of Example 1, and a PMMA recovery solution is treated. The initial PMMA content is 50%, the solvent is a mixed solution 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 by a heat exchanger, and the feeding pressure is 4 MPaG;

[0128] (2) Liquid-liquid phase separation: the solution enters the polymer desolventizing separation equipment and stays in the phase separation zone for 16 min, the entrained polymer content in the top light phase is 0.04%, and the PMMA content in the heavy phase is 67%;

[0129] (3) Flash evaporation under reduced pressure: the heavy phase is sent into the flash evaporation equipment, and solvent flash evaporation is carried out at 200°C, and a melt with a PMMA concentration of 95% is obtained at the bottom.

[0130] Example 5

[0131] The same process as Example 1 is used to treat a 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 feeding pressure is 5 MPaG;

[0133] (2) Liquid-liquid phase separation: the solution enters the polymer desolventizing separation equipment and stays in the phase separation zone for 20 min, the entrained polymer content in the top light phase is 0.04%, and the PP content in the heavy phase is 70%;

[0134] (3) Flash evaporation under reduced pressure: the heavy phase is sent into the flash evaporation equipment, and solvent flash evaporation is carried out at 180°C, and a melt with a PP concentration of 96% is obtained at the bottom.

[0135] Comparative Example 1

[0136] The medium under the same conditions as Example 1 is taken, a multi-stage heating and flash evaporation process is used, which is a three-stage heating and three-stage flash evaporation process, and the devices used are as follows: Figure 5as shown.

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

[0138] (2) Second heating + flash distillation: The polymer solution at the bottom of the first flash distillation device is heated to 195°C by a second heat exchanger and then enters a second flash distillation device. The operating pressure of the second flash distillation device is 20 kPaG. Part of the solvent is flashed, and a polymer solution with a cycloolefin copolymer concentration of 80% is obtained at the bottom.

[0139] (3) Third heating + flash distillation: The polymer solution at the bottom of the second flash distillation device is heated to 210°C by a third heat exchanger and then enters a third flash distillation device. The operating pressure of the third flash distillation device is 10 kPaG. Part of the solvent is flashed, and a melt with a cycloolefin copolymer concentration of 96% is obtained at the bottom.

[0140] Comparative Example 2

[0141] Under the same conditions as in Example 1, the medium was taken, and the process of liquid-liquid separation of the homogeneous polymer solution in patent CN113164898A was used. The devices used are as shown in Figure 6 .

[0142] (1) Preheating: The cycloolefin 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 a polymer desolventizing separation device (without internal parts, specifically without the annular baffle zone, cyclone umbrella distributor, and perforated plate zone of the present application), and stays in the phase separation zone for 20 min. After phase separation, the light phase is collected through the overflow port, and the heavy phase at the bottom contains 47% cycloolefin copolymer.

[0144] (3) 1st stage vacuum flash distillation: The heavy phase is sent to a first flash distillation device, which operates at a pressure of 10 kPaG and a temperature of 210°C. Solvent is flashed, and a melt with a cycloolefin copolymer concentration of 76% is obtained at the bottom.

[0145] (4) 2nd stage vacuum flash distillation: The medium at the bottom of the first flash distillation device enters a second flash distillation device, which operates at a pressure of 2 kPaG and a temperature of 210°C. Solvent is flashed, and a melt with a cycloolefin copolymer concentration of 96% is obtained at the bottom.

[0146] Comparative Example 3

[0147] The process is the same as that in Example 1, except that the cyclone umbrella distributor in the polymer desolventizing separation device is removed. The devices used are as shown in Figure 7 , and the method steps are as follows:

[0148] (1) Preheating: the cycloolefin copolymer recovery solution was heated to 210°C by a heat exchanger, the feed pressure was 5 MPaG;

[0149] (2) Liquid-liquid phase separation: the solution entered the polymer desolventizing separation equipment, and stayed in the phase separation zone for about 20 min. After phase separation, the light phase was collected through the overflow port. The entrained polymer content in the top light phase was 0.02%, and the cycloolefin copolymer content in the bottom heavy phase was 56%;

[0150] (3) Vacuum flash evaporation: the heavy phase was sent to the first flash evaporation equipment, and solvent flash evaporation was carried out at 210°C. The cycloolefin copolymer melt with a concentration of 80% was obtained at the bottom. The melt was continuously sent to the second flash evaporation equipment, and the operating pressure was reduced to 2 kPaG. Solvent flash evaporation was carried out at 210°C, and the cycloolefin copolymer melt with a concentration of 96% was obtained at the bottom.

[0151] Comparative Example 4

[0152] The process was the same as that of Example 1, except that the orifice plate in the polymer desolventizing separation equipment was removed. The used device was as shown in Figure 8 The method steps were as follows:

[0153] (1) Preheating: the cycloolefin copolymer recovery solution was heated to 210°C by a heat exchanger, the feed pressure was 5 MPaG;

[0154] (2) Liquid-liquid phase separation: the solution entered the polymer desolventizing separation equipment, and stayed in the phase separation zone for 20 min. After phase separation, the light phase was collected through the overflow port. The entrained polymer content in the top light phase was 0.02%, and the cycloolefin copolymer content in the bottom heavy phase was 54%;

[0155] (3) Vacuum flash evaporation: the heavy phase was sent to the first flash evaporation equipment, and solvent flash evaporation was carried out at 210°C. The cycloolefin copolymer melt with a concentration of 80% was obtained at the bottom. The melt was continuously sent to the second flash evaporation equipment, and the operating pressure was reduced to 2 kPaG. Solvent flash evaporation was carried out at 210°C, and the cycloolefin copolymer melt with a concentration of 96% was obtained at the bottom.

[0156] Example 6

[0157] The difference from Example 1 was only that the taper angle of the conical body was 10°.

[0158] Example 7

[0159] The difference from Example 1 was only that the taper angle of the conical body was 100°.

[0160] Example 8

[0161] The difference from Example 1 was only that the arc angle of the arc baffle was 10°.

[0162] Example 9

[0163] The difference from example 1 is only 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, i.e., examples 6-9. The relative energy consumption is based on the actual energy consumption of example 1 (set as 1), and the ratio is calculated by "actual energy consumption of target object ÷ actual energy consumption of example 1". The ratio is shown in Table 1 below.

[0165] Table 1

[0166]

[0167] As shown above, it is obvious that the method of the present application can realize efficient and low-energy devolatilization of polymers. At the same time, the process control is simple, and the phase separation of the polymer devolatilization and separation equipment increases the polymer content from 40-50% to 60-70%, which reduces the solvent evaporation amount of the flash evaporation equipment. Compared with the traditional multi-stage heating flash evaporation process, the total energy consumption is significantly reduced. In addition, the comparison between example 1 and the liquid-liquid separation (without internal parts) process of the homogeneous polymer solution in patent number CN113164898A (comparative example 2) shows that the liquid-liquid separation tank of the present application can significantly improve the solid content in the polymer solution, while the solid content at the bottom of the liquid-liquid separation tank in the patent does not change significantly.

[0168] The above describes the preferred embodiments of the present application, but the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0169] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0170] Furthermore, any combination of various different embodiments of the present application can also be made, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. A polymer desolventizing and separation device, characterized in that, The polymer desolventizing and separation equipment includes: The polymer solution inlet, annular baffle zone, swirling umbrella distributor, orifice plate zone, and polymer outlet are connected in sequence. The annular baffle area is equipped with a solvent outlet.

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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