A devolatilization system for polyolefin elastomers
By combining the pre-devouring unit and the static devouring unit, and using a distributor to separate the gas and liquid phases, the problem of blockage of volatiles with high viscosity and poor flowability is solved, achieving efficient removal and continuous operation of the unit.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING PETROCHEM ENG
- Filing Date
- 2025-06-20
- Publication Date
- 2026-07-14
AI Technical Summary
Existing technologies cannot effectively remove highly viscous, poorly fluid volatiles, leading to blockages in pipes, instruments, or equipment, thus affecting the operation of the equipment.
The process employs a combination of pre-devouring unit and static devouring unit. The static devouring unit includes N-stage static devouring devices connected in series and N-1 heat exchange devices. A distributor is installed to separate the gas and liquid phases, and the gas and material are separated by utilizing the density difference between the gas and liquid.
It achieves efficient separation of high-viscosity, poorly flowing volatile components, avoids equipment blockage, and ensures continuous operation of the unit and product quality.
Smart Images
Figure CN224484971U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of polymer devolatilization technology, specifically to a devolatilization system for polyolefin elastomers. Background Technology
[0002] Solution polymerization typically involves the catalytic polymerization of monomers in a polymerization reactor in the presence of a catalyst and an inert solvent. The resulting polymer is also dissolved in the solvent. After the reaction is complete, the polymer solution contains some unpolymerized monomers, solvent, and reaction byproducts, which are collectively referred to as volatiles.
[0003] The synthesis of polymers typically includes polymerization and devolatilization stages. The products obtained from polymerization contain volatiles, which directly affect the quality and performance of the polymer, and can even pollute the environment and harm health. Therefore, a devolatilization stage is needed to remove or recover volatiles remaining in the polymer. This stage not only recovers monomers and solvents, but more importantly, it ensures the volatile content of the polymer product after removal. Particularly in the synthesis of vinyl polyolefin elastomers (POE), POE has high viscosity and poor flowability, and the volatile content in the polymerization reactor can reach 60%-90%, making the devolatilization process difficult, energy-intensive, and difficult to completely remove volatiles. Therefore, there is an urgent need to develop a low-energy-consumption, high-efficiency devolatilization system for elastomers.
[0004] Related technologies disclose a solution polymerization process that uses a liquid-liquid phase separation process to separate the polymer. A portion of the solvent and unreacted monomers are evaporated, increasing the polymer solids content in the reaction product from 15wt%-17wt% to 21wt%-23wt%. The polymer-rich phase is then conveyed to multiple series-connected devolatilization vessels. Each devolatilization vessel operates at a lower pressure than the previous one, increasing the polymer solids content to 92wt%-95wt%. The remaining 5wt%-8wt% volatile polymer solution is sent to an extruder for further devolatilization before granulation. Related technologies also disclose a system and method for polymer devolatilization. This method employs a combined devolatilization mode of flash pre-devolatilization unit, static devolatilization unit, and dynamic devolatilization unit for polymer separation. The static devolatilization unit uses multi-stage series static devolatilizers, with the final stage increasing the polymer content to 85wt%-99.9wt%, before being sent to an extruder for dynamic devolatilization before granulation. However, during the devolatilization process, a large amount of volatiles are removed, but a small amount of polymer is also carried away. In practical applications, regardless of whether droplet separation is achieved through heat exchanger condensation, gas-liquid separators, demisters, or cyclone separators, polymer can cause blockages in pipelines, instruments, or equipment, leading to plant shutdowns. This is especially true for processes where the extruder is involved in the devolatilization process; if the extruder's operation is affected, the entire plant needs to be shut down, resulting in significant losses and high risks.
[0005] Therefore, how to effectively remove volatile components with high viscosity and poor flowability is a technical problem that urgently needs to be solved in this field. Utility Model Content
[0006] In view of this, the present invention provides a devolatilization system for polyolefin elastomers to solve the problem that the existing technology cannot remove volatile components with high viscosity and poor flowability, which causes blockage of pipes, instruments or equipment.
[0007] In a first aspect, the present invention provides a devolatilization system for polyolefin elastomers, the devolatilization system comprising a pre-devolatilization unit and a static devolatilization unit connected in sequence;
[0008] The static devolatilization unit includes N stages of static devolatilization devices connected in series and N-1 heat exchange devices. The heat exchange devices are located between the i-th stage static devolatilization device and the (i-1)-th stage static devolatilization device, where 2≤i≤N.
[0009] A first distributor is installed in the inner cavity of the first-stage static devouring device, and the two ends of the first distributor are respectively connected to the inlet of the first-stage static devouring device and the outlet of the first-stage heat exchange device.
[0010] The first distributor includes a first pipe distributed circumferentially along the inner cavity of the first-stage static devouring device, and the first pipe is provided with a plurality of first holes;
[0011] A second distributor is installed in the inner cavity of each of the second-stage static devouring device to the (N-1)th-stage static devouring device. The second distributor is connected to the outlet of the m-th-stage heat exchange device, where 2≤m≤N-1.
[0012] The second distributor includes a second pipe distributed circumferentially along the inner cavity of the second-stage static devouring device or the (N-1)th-stage static devouring device. The second pipe is provided with a plurality of second holes, the porosity of which is less than that of the first holes.
[0013] In some alternative implementations, the ratio of the distance H1 from the geometric center of the first distributor to the outer edge of the first pipe to the inner diameter R1 of the first-stage static devouring device is 1:1.25-2.5.
[0014] In some alternative embodiments, the distance H2 from the geometric center of the second distributor to the outer edge of the second pipe is 1:1.25-3 to the inner diameter R2 of the second-stage static devouring device or the (N-1)th-stage static devouring device.
[0015] In some alternative embodiments, the first pipe and / or the second pipe may be at least one of the following shapes: annular or square.
[0016] In some alternative implementations, the first conduit is a concentric ring, comprising an inner ring and an outer ring.
[0017] In some alternative embodiments, the diameter of the first hole and / or the second hole is 5mm-20mm, and the spacing between adjacent holes is 2-10 times the diameter.
[0018] In some alternative embodiments, a first conveying device is also included, the inlet of which is connected to the outlet of the i-th stage static devouring device, and the outlet of which is connected to the inlet of the (i+1)-th stage static devouring device.
[0019] In some alternative implementations, heating devices are provided in all stages from the second-stage static devolatilization device to the (N-1)th-stage static devolatilization device.
[0020] In some alternative embodiments, the pre-devouring unit includes a pre-devouring device, a condensation device, a reboiling device, and a second conveying device;
[0021] A pre-devouring unit, the inlet of which is connected to the outlet of the polymerization reactor, the pre-devouring unit including a bottom liquid outlet and a top gas outlet;
[0022] A condensing unit, the inlet of which is connected to the top gas outlet of the pre-devouring unit, and the outlet of which is connected to the top inlet of the pre-devouring unit;
[0023] The reboiling device has its inlet connected to the bottom liquid outlet of the pre-devouring device and its outlet connected to the bottom inlet of the pre-devouring device 101.
[0024] The second conveying device has its inlet connected to the outlet of the pre-devouring device's bottom liquid and its outlet connected to the static devouring unit.
[0025] In some alternative implementations, a solvent recovery unit is also included, the inlet of which is connected to the volatile outlet of each stage of the static devolatilization reaction unit.
[0026] In some alternative implementations, an extrusion granulation unit is also included, the inlet of which is connected to the Nth stage static devolatilization unit.
[0027] Compared with the prior art, the technical solution of this utility model has the following advantages:
[0028] 1. The present invention provides a devolatilization system for polyolefin elastomers, comprising a pre-devolatilization unit and a static devolatilization unit connected in sequence; the static devolatilization unit comprises N stages of static devolatilization devices connected in series and N-1 heat exchange devices, wherein the heat exchange devices are located between the i-th stage static devolatilization device and the (i-1)-th stage static devolatilization device, 2≤i≤N; a first distributor is provided in the inner cavity of the first stage static devolatilization device, and the two ends of the first distributor are respectively connected to the inlet of the first stage static devolatilization device and the outlet of the first stage heat exchange device; the first distributor... The device includes a first pipe distributed circumferentially along the inner cavity of the first-stage static devolatilization device, and the first pipe has a plurality of first holes; a second distributor is provided in the inner cavity of each of the second-stage to the (N-1)th-stage static devolatilization devices, and the second distributor is connected to the outlet of the m-th-stage heat exchange device, where 2≤m≤N-1; the second distributor includes a second pipe distributed circumferentially along the inner cavity of the second-stage static devolatilization device or the (N-1)th-stage static devolatilization device, and the second pipe has a plurality of second holes, the porosity of the second holes being less than the porosity of the first holes. This invention incorporates a distributor within a static devolatilization device. When the polymer solution enters the first-stage static devolatilization device and / or the first-stage heat exchange device, the volatiles have already changed from the liquid phase to the gas phase. However, the viscosity of the solution is very high, especially in the second-stage static devolatilization device, where the polymer solution concentration is very high. The volatiles that have become gaseous are trapped inside the solution in the form of bubbles and are difficult to escape, resulting in unqualified devolatilization and affecting subsequent equipment production and product quality. By installing a distributor, the gas and liquid phases in the polymer solution are separated, effectively squeezing out the bubbles or preventing them from being trapped by the solution. During the descent process within the static devolatilization device, the gas is separated from the polymer solution by utilizing the density difference between the gas and liquid. In the Nth-stage static devolatilization process, the volatile content is low, and the solution volume is significantly reduced. The remaining volatiles can then be removed using the static devolatilization device. Attached Figure Description
[0029] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0030] Figure 1 This is a devolatilization system for vinyl elastomers according to an embodiment of the present invention;
[0031] Figure 2 This is a schematic diagram of the structure of the first distributor according to an embodiment of the present utility model;
[0032] Figure 3 This is a schematic diagram of the structure of the second distributor according to an embodiment of the present invention;
[0033] Explanation of reference numerals in the attached figures:
[0034] Pre-devouring unit 01, static devouring unit 02, solvent recovery unit 03, extrusion granulation unit 04, pre-devouring device 101, condensation device 102, reboiling device 103, first conveying device 104, first-stage static devouring device 201, first-stage heat exchange device 202, second conveying device 203, second-stage static devouring device 301, first-stage heating device 302, third conveying device 303, second-stage heat exchange device 305, third-stage static devouring device 401, second-stage heating device 402, fourth conveying device 403, compression device 404, first pipeline 204, second pipeline 304, third pipeline 405. Detailed Implementation
[0035] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described herein. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.
[0036] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.
[0037] The present invention will be further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention.
[0038] Example
[0039] like Figure 1 As shown, this embodiment provides a devolatilization system for polyolefin elastomers, including: a pre-devolatilization unit 01, a static devolatilization unit 02, a solvent recovery unit 03, and an extrusion granulation unit 04;
[0040] The pre-devouring unit includes a pre-devouring device 101, a condensing device 102, a reboiling device 103, and a first conveying device 104, specifically;
[0041] The pre-devouring unit 101 has its inlet connected to the outlet of the polymerization reactor, including the bottom liquid outlet and the top gas outlet;
[0042] It should be noted that the pre-devouring device 101 includes at least one of a distillation column and a flash distillation column, preferably a distillation column; the operating temperature of the distillation column is 160℃-220℃ (bottom of the column), the pressure is 0.5MPaG-2.0MPaG, and the ethylene content in the polymer solution in the bottom of the column is ≤0.05wt%.
[0043] The reboiling unit 103 has its inlet connected to the bottom liquid outlet of the pre-devouring unit 101, and its outlet connected to the bottom inlet of the pre-devouring unit 101.
[0044] The condenser 102 has its inlet connected to the top gas outlet of the pre-devouring unit 101, and its outlet connected to the top inlet of the pre-devouring unit 101.
[0045] The inlet of the first conveying device 104 is connected to the bottom liquid outlet of the pre-devouring device 101;
[0046] The static devolatilization unit 02 includes a first-stage static devolatilization device 201, a second-stage conveying device 203, a first-stage heating device 302, a second-stage static devolatilization device 301, a third-stage conveying device 303, a second-stage heating device 402, a third-stage static devolatilization device 401, and a fourth-stage conveying device 403 connected in sequence.
[0047] The inlet of the first-stage heat exchanger 202 is connected to the outlet of the second conveying device 203, and its inlet is connected to the inlet of the first-stage static devolatilization device 201.
[0048] The inlet of the second-stage heat exchanger 305 is connected to the outlet of the third conveying device 303, and its inlet is connected to the inlet of the second-stage static devolatilization device 301.
[0049] The inlet of the compression device 404 is connected to the volatile matter outlet of the third-stage static devolatilization device 401;
[0050] A first distributor is installed inside the cavity of the first-stage static devouring device, with its two ends connected to the inlet of the first-stage static devouring device and the outlet of the first-stage heat exchange device, respectively. Figure 2 As shown, the first distributor includes a first pipe distributed circumferentially along the inner cavity of the first-stage static devouring device, and the first pipe is provided with a plurality of first holes; as Figure 3 As shown, a second distributor is installed in the inner cavity of both the second-stage and third-stage static devolatilization devices, and is connected to the outlet of the second-stage and third-stage heat exchange devices, respectively. It includes a second pipe distributed circumferentially along the inner cavity of the second-stage and third-stage static devolatilization devices, with several second holes on the second pipe. The porosity of the second hole is less than that of the first hole. The distance H1 from the geometric center of the first distributor to the outer edge of the first pipe is in the ratio of 1:1.25-2.5 to the inner diameter R1 of the first-stage static devolatilization device; the distance H2 from the geometric center of the second distributor to the outer edge of the second pipe is in the ratio of 1:1.25-3 to the inner diameter R2 of the second-stage static devolatilization device or the (N-1)th-stage static devolatilization device; the first and second pipes are annular in shape; the first pipe is a concentric ring, including an inner ring and an outer ring; the diameter of the first hole and / or the second hole is 5mm-20mm, and the spacing between adjacent holes is 2-10 times the diameter.
[0051] Solvent recovery unit 03 has its inlet connected to the volatile outlets of the first-stage static devolatilization device 201, the second-stage static devolatilization device 301, and the third-stage static devolatilization device 401, respectively.
[0052] The inlet of the extrusion granulation unit 04 is connected to the outlet of the fourth conveying device 403.
[0053] The pre-devouring unit 01, located downstream of the olefin polymerization reactor, is used to receive polymer solution from the polymerization reactor. The polymer solution enters the pre-devouring unit 101 for distillation separation. The ethylene separated at the top of the column is condensed by the condenser 102. The liquid phase is returned to the pre-devouring unit 101, and the gas phase, which is unreacted monomer, is returned to the polymerization reactor for recycling. A portion of the bottom liquid separated from the pre-devouring unit 101 is heated by the reboiling device 103 and then returned to the pre-devouring unit 101.
[0054] It should be noted that the monomers in the polymerization reaction are α-olefins, including at least one of ethylene, ethylene and propylene, and 1-butene; the solvents in the polymerization reaction include at least one of pentane, isopentane, hexane, isohexane, heptane, and isohexane, preferably hexane; the polymer solution obtained after the reaction includes an elastomer polymer and 60wt%-90wt% volatiles, which include unreacted raw material monomers, solvents, and byproducts of the polymerization reaction;
[0055] The static devolatilization unit 02, located downstream of the pre-devolatilization unit 01, includes multiple static devolatilization devices connected in series, preferably three. Depending on the polymer solution processing capacity and concentration requirements, one additional static devolatilization device can be added or removed to achieve qualified devolatilization. The static devolatilization unit 02 receives the polymer solution from the pre-devolatilization unit and removes the solvent and small amounts of heavy components byproducts of the polymerization reaction through the static devolatilization devices, obtaining a high-purity molten polyolefin elastomer polymer, which is then sent to the downstream extrusion granulation unit for polymer granulation. Specifically, the remaining portion separated from the bottom of the pre-devolatilization unit 101... The liquid in the reactor is conveyed via the first conveying device 104 to the first-stage static devolatilization unit 201 for flash devolatilization. The temperature in the first-stage static devolatilization unit 201 is 160℃-220℃, and the pressure is 0.2MPaG-0.6MPaG. The polymer content in the first-stage mixture is 30wt%-60wt%. The removed volatiles are sent to the solvent recovery unit 03. The first-stage mixture is then conveyed via the second conveying device 203 and the first pipeline 204. A portion of the mixture is heated to 160℃-220℃ by the first-stage heat exchanger 202 and returned to the first-stage static devolatilization unit 201 to replenish the heat required for volatile evaporation. The remaining portion is sent to the first-stage heating device 302. Heated to 180℃-260℃, the mixture enters the second-stage static devolatilization unit 301 for flash devolatilization under lower pressure. The temperature in the second-stage static devolatilization unit 301 is 180℃-260℃, and the pressure is 0-0.2 MPaG. The polymer content in the secondary mixture is 90wt%-99wt%. The removed volatiles are sent to the solvent recovery unit 03. A portion is heated to 160℃-220℃ by the second-stage heat exchanger 305 and returned to the second-stage static devolatilization unit 301 to replenish the heat required for volatile evaporation. The remaining portion is sent to the second-stage heating unit 402 and heated to 200℃-280℃ before entering the third-stage static devolatilization unit. Flash devolatilization continues in unit 401. The temperature in the third-stage static devolatilization unit is 200℃-280℃, and the pressure is 0-50KPa(A). In the three-stage mixture, the polymer content is ≥99.97wt%, and the volatile content is ≤300ppm. The third-stage static devolatilization unit operates under negative pressure, and the negative pressure of the system is controlled by the compression device 404. The removed volatiles are sent to the solvent recovery unit 03 via the compression device 404 for solvent recovery and recycling. The mixture from the third-stage static devolatilization unit is sent to the extrusion granulation unit 04 via the fourth conveying device 403 and the third pipeline 405 for polymer granulation to obtain polymer granule products.
[0056] By employing a combination of pre-devouring and static devouring processes, and by controlling the temperature and pressure of each devouring unit, environmentally friendly polymer products with VOC content of less than 300ppm can be obtained. This also avoids the problem of pipe or equipment blockage during the volatile matter recovery process, and eliminates the need to add dynamic devouring to the extrusion system.
[0057] It should be noted that the cooling medium in the condenser 102 is circulating cooling water; the heating medium in the reboiler 103 is steam; the heating mediums in the first-stage heat exchanger 202, the first-stage heating device 302, and the second-stage heating device 402 are heat transfer oil, achieving the temperatures required by each stage of the static devolatilization device; the third-stage static devolatilization device 401 operates under negative pressure, with the vacuum level controlled by the compression device 404; the first pipeline 204, the second pipeline 304, and the third pipeline 405 all use hot oil jacketed pipelines for heating to ensure the fluidity of the polymer solution and avoid pipeline blockage; the first-stage static devolatilization device 201, the second-stage static devolatilization device 301, and the third-stage static devolatilization device 401 use either a half-jacket or a full-jacket, with a half-jacket preferred;
[0058] It should be noted that the first-stage static devolatilization device is equipped with a frame agitator suitable for high-viscosity fluids. The first-stage static devolatilization device has the largest amount of volatiles to be removed, and it is necessary to configure forced material circulation and agitation to work together to ensure that external heat can be replenished in the first-stage static devolatilization device through the first-stage heat exchange device.
[0059] It should be noted that the second-stage and third-stage heat exchange devices are drop-bar type heat exchangers suitable for high-viscosity fluids. They can not only ensure sufficient heat transfer between fluid media and allow the solvent in the polymer to evaporate, but also separate the solvent from the liquid phase of the polymer in real time. Then, the gas and liquid phases are separated by a static devolatilizer, which can remove the volatiles.
[0060] The devolatilization system described above is used to remove devolatilization from a polyolefin elastomer polymer solution after polymerization, which contains ethylene (the raw material) and heptane (the solvent) from the polymerization process. The polymer solution contains 11 wt% polyolefin elastomer and 89 wt% volatile matter (solvent, unreacted ethylene monomer, and a small amount of byproduct heavy components). The polymer solution is pumped to the devolatilization system at a rate of 10642 kg / h for devolatilization, including the following steps:
[0061] (1) In the pre-devouring unit 01, the polymer solution is fed into the pre-devouring device 101 for distillation and separation. The inlet temperature of the pre-devouring device is 95°C and the operating pressure is 1.0 MPaG. Ethylene and some heptane are distilled out from the top of the column. The top gas is condensed to 40°C by the condenser 102. The condensed liquid phase is refluxed back to the top of the pre-devouring device 101. The non-condensable gas, ethylene, is taken out from the top of the column, pressurized by the compressor, and returned to the polymerization reactor for recycling. The polymer content in the bottom liquid is 12wt% and the volatile content is 88wt%. Part of it is returned to the pre-devouring tower device 101 by steam heating through the reboiling device 103. The bottom operating temperature is 160°C-220°C, preferably 190°C. The other part of the bottom liquid is sent to the static devouring unit 02 through the first conveying device 104.
[0062] (2) In the static devolatilization unit 02, a three-stage devolatilization process is adopted, specifically: the bottom liquid from the pre-devolatilization unit first enters the first-stage static devolatilization unit 201 for flash devolatilization. The inlet temperature of the first-stage static devolatilization unit 201 is 195℃ and the inlet pressure is 1.5MPa. The temperature in the first-stage static devolatilization unit 201 is 180℃ and the pressure is 0.4MPa. The removed volatiles are sent to the solvent recovery unit 03 for recycling. The bottom liquid of the first-stage static devolatilization unit is sent out by the second conveying device 203 to obtain the first-stage outlet material. The mass content of volatiles in the first-stage outlet material is detected to be 43wt% and the mass content of polymer is 57wt%. A portion of the first-stage outlet material is heated by the first-stage heat exchanger 302 and returned to the first-stage static devolatilization unit 201 to supplement the heat required for the evaporation of volatiles. The outlet temperature of the first-stage heat exchanger 202 is 200℃ and the outlet pressure is 1.2MPa.
[0063] (3) The remaining primary outlet material is sent to the primary heating device 302 for heating. The outlet temperature of the primary heating device 302 is 245℃ and the outlet pressure is 2.1MPa. Then it enters the secondary static devolatilization device 301 for flash devolatilization under lower pressure. The temperature in the secondary static devolatilization device 301 is 220℃ and the pressure is 0.05MPa. The removed volatiles are sent to the solvent recovery unit 03 for recycling. The adhesive liquid at the bottom of the secondary static devolatilization device is sent out through the third conveying device 303 to obtain the secondary outlet material. The mass content of volatiles in the secondary outlet material is 2%, and the mass content of polymer is 98wt%.
[0064] (4) The secondary outlet material is sent to the second stage heating device 402 for heating. The outlet temperature of the second stage heating device 402 is 255℃ and the outlet pressure is 11MPa. Then it enters the third stage static devolatilization device 401 for further flash devolatilization. The temperature in the third stage static devolatilization device 401 is 250℃ and the pressure is 1-10kPa (absolute pressure). The third stage static devolatilization device is operated under negative pressure. The negative pressure of the system is controlled by the frequency conversion of the vacuum pump 404. The removed volatiles are sent to the solvent recovery unit 03 for recycling via the compression device 404. The adhesive liquid at the bottom of the third stage static devolatilization device is sent out via the fourth conveying device 403 to obtain molten adhesive liquid. The mass content of volatiles in the molten adhesive liquid is detected to be 0.02%, and the polymer mass content is 99.98wt%.
[0065] (5) The molten adhesive is sent to the extrusion granulation unit 04 for polymer granulation to obtain polymer granule products.
[0066] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A devolatilization system for polyolefin elastomers, characterized in that, The devolatilization system includes a pre-devolatilization unit and a static devolatilization unit connected in sequence; The static devolatilization unit includes N stages of static devolatilization devices connected in series and N-1 heat exchange devices. The heat exchange devices are located between the i-th stage static devolatilization device and the (i-1)-th stage static devolatilization device, where 2≤i≤N. A first distributor is installed in the inner cavity of the first-stage static devouring device, and the two ends of the first distributor are respectively connected to the inlet of the first-stage static devouring device and the outlet of the first-stage heat exchange device. The first distributor includes a first pipe distributed circumferentially along the inner cavity of the first-stage static devouring device, and the first pipe is provided with a plurality of first holes; A second distributor is installed in the inner cavity of each of the second-stage static devouring device to the (N-1)th-stage static devouring device. The second distributor is connected to the outlet of the m-th-stage heat exchange device, where 2≤m≤N-1. The second distributor includes a second pipe distributed circumferentially along the inner cavity of the second-stage static devouring device or the (N-1)th-stage static devouring device. The second pipe is provided with a plurality of second holes, the porosity of which is less than that of the first holes.
2. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, The ratio of the distance H1 from the geometric center of the first distributor to the outer edge of the first pipe to the inner diameter R1 of the first stage static devouring device is 1:1.25-2.
5.
3. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, The distance H2 from the geometric center of the second distributor to the outer edge of the second pipe is 1:1.25-3, which is the ratio of the inner diameter R2 of the second-stage static devouring device or the (N-1)th-stage static devouring device.
4. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, The shape of the first pipe and / or the second pipe is at least one of annular or square.
5. The devolatilization system for polyolefin elastomers according to any one of claims 1, 2, or 4, characterized in that, The first pipe is a concentric ring, consisting of an inner ring and an outer ring.
6. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, The diameter of the first hole and / or the second hole is 5mm-20mm, and the spacing between adjacent holes is 2-10 times the diameter.
7. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, It also includes a first conveying device, the inlet of which is connected to the outlet of the i-th stage static devouring device, and the outlet of which is connected to the inlet of the i+1-th stage static devouring device; And / or, heating devices are provided in all stages from the second-stage static devolatilization device to the (N-1)th-stage static devolatilization device.
8. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, The pre-devouring unit includes a pre-devouring device, a condensation device, a reboiling device, and a second conveying device; A pre-devouring unit, the inlet of which is connected to the outlet of the polymerization reactor, the pre-devouring unit including a bottom liquid outlet and a top gas outlet; A condensing unit, the inlet of which is connected to the top gas outlet of the pre-devouring unit, and the outlet of which is connected to the top inlet of the pre-devouring unit; The reboiler has its inlet connected to the bottom liquid outlet of the pre-devouring unit and its outlet connected to the bottom inlet of the pre-devouring unit. The second conveying device has its inlet connected to the outlet of the pre-devouring device's bottom liquid and its outlet connected to the static devouring unit.
9. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, It also includes a solvent recovery unit, the inlet of which is connected to the volatile matter outlet of each stage of the static devolatilization reaction unit.
10. The devolatilization system for polyolefin elastomers according to claim 1, characterized in that, It also includes an extrusion granulation unit, the inlet of which is connected to the Nth stage static devolatilization unit.