Polypropylene preparation device
By designing a polypropylene preparation device including a propylene purification unit, a polymerization reactor, a filter flash drying kettle and a mixed solvent storage tank, the problem of difficulty in reducing ash in the production of polypropylene in the prior art is solved, and the separation of high-purity products and the simplification of the production process is achieved.
Patent Information
- Application Number
- CN202421423377.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-20
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-06-20
AI Technical Summary
In the prior art, it is difficult to effectively reduce ash when producing polypropylene, resulting in complex production processes, high cost, and large consumption of washing solvents.
A polypropylene preparation device is designed, including a propylene purification unit, a polymerization reactor, a filter flash drying kettle and a mixed solvent storage tank. The polymerization reaction is carried out in the polymerization reactor by purifying propylene, and evaporation and drying treatment are carried out in the filter flash drying kettle. Combined with the washing treatment of the mixed solvent, the high-purity separation of the product is achieved.
The device can reduce the ash content, reduce the amount of washing solvents used, reduce production costs, and simplify recycling and processing steps and costs while shortening the production process of polypropylene.
Smart Images
Figure CN222842117U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of polypropylene, in particular to a preparation device of polypropylene. Background Art
[0002] Polypropylene (PP) is one of the fastest growing varieties of commercial plastics in recent years. It is a widely used polymer material and is known for its light weight, cleanliness, high rigidity and high transparency. PP electrical film is a high-frequency dielectric insulation material with excellent electrical properties. Due to its high dielectric strength, low dielectric loss, reasonable roughness, high film formation rate, low price, moisture-proof and water-absorption, it is widely used in capacitors, power electronics and other fields.
[0003] At present, in order to improve the purity of PP, if the ash content is reduced by washing PP in a washing tower, a large amount of solvent is consumed in the process, and the recycling steps and recycling costs are high. If the ash content is reduced by polymerization using a more active catalyst and an organic electron donor, the operation is difficult and it is not easy to industrialize and mass-produce PP. Utility Model Content
[0004] The utility model aims to provide a polypropylene preparation device, which can improve the purity of polypropylene, shorten the production process of polypropylene and reduce the production cost.
[0005] In order to achieve the above object, the utility model provides a polypropylene preparation device, comprising:
[0006] A propylene refining unit, a polymerization reactor, a filtration flash drying reactor and a mixed solvent storage tank, wherein the outlet of the propylene refining unit is connected to the feed inlet of the polymerization reactor, the product outlet of the polymerization reactor is connected to the feed inlet of the filtration flash drying reactor, and the outlet of the mixed solvent storage tank is connected to the liquid inlet of the filtration flash drying reactor;
[0007] Wherein, the propylene refining unit comprises a propylene storage tank, a dehydration tower, a desulfurization tower, a deoxygenation tower, a decarbon monoxide removal tower and a refined propylene storage tank; the outlet of the propylene storage tank is connected to the inlet of the dehydration tower, the outlet of the dehydration tower is connected to the inlet of the deoxygenation tower through the desulfurization tower, the outlet of the deoxygenation tower is connected to the inlet of the refined propylene storage tank through the decarbon monoxide removal tower, and the outlet of the refined propylene storage tank is connected to the feed port of the polymerization reactor.
[0008] Compared with the prior art, the preparation device of polypropylene provided by the utility model includes a propylene refining unit, a polymerization reactor, a filtration flash drying reactor and a mixed solvent storage tank, wherein the outlet of the propylene refining unit is connected to the feed port of the polymerization reactor, the product outlet of the polymerization reactor is connected to the feed port of the filtration flash drying reactor, and the outlet of the mixed solvent storage tank is connected to the liquid inlet of the filtration flash drying reactor. Therefore, in the process of producing polypropylene, refined propylene can fully carry out polymerization reaction in the polymerization reactor, and the product obtained by the reaction enters the feed port of the filtration flash drying reactor through the product outlet of the polymerization reactor for evaporation treatment and drying treatment, so that some impurities contained in the product can be removed, and a product with relatively high purity is obtained. This process is not only conducive to reducing the ash content in the product, but also conducive to reducing the difficulty of subsequent washing steps, shortening the production process of polypropylene, reducing the amount of washing solvent used, and reducing production costs. Then, the mixed solvent is passed into the liquid inlet of the filtration flash drying reactor along the outlet of the mixed solvent storage tank to wash the product and separate the polypropylene product and residual impurities. Among them, the mixed solvent can dissolve the random substances in the product, which is conducive to reducing the ash content in the product and separating a polypropylene product with higher purity. The process is less difficult to operate and is conducive to industrial large-scale production of polypropylene. In addition, the polypropylene preparation device provided by the utility model can complete the washing treatment of the product without setting a washing tower. Compared with the washing tower, the consumption of the mixed solvent in the polypropylene preparation device provided by the utility model is lower, so that the ash content can be reduced, the purity of the polypropylene product can be ensured, the production process of polypropylene can be simplified, and the recovery and processing cost and energy consumption of the mixed solvent can be reduced.
[0009] In addition, the propylene refining unit provided by the utility model includes a propylene storage tank, a dehydration tower, a desulfurization tower, a deoxygenation tower, a carbon monoxide removal tower and a refined propylene storage tank. Among them, the outlet of the propylene storage tank is connected to the inlet of the dehydration tower, the outlet of the dehydration tower is connected to the inlet of the deoxygenation tower through the desulfurization tower, the outlet of the deoxygenation tower is connected to the inlet of the refined propylene storage tank through the carbon monoxide removal tower, and the outlet of the refined propylene storage tank is connected to the feed port of the polymerization reactor. Based on this, in the process of producing polypropylene, by refining the raw material propylene, the probability of impurities in the raw material propylene destroying the active center or adding to the polymerization chain can be reduced, which is conducive to ensuring the smooth progress of the polymerization reaction.
[0010] It is worth noting that, compared with the traditional slurry polymerization method, which requires the use of multiple polymerization reactors for polymerization reaction, in the preparation device provided by the utility model, only one polymerization reactor is provided. In other words, the polymerization reaction of refined propylene is completed in one step, which is conducive to shortening the reaction process of polypropylene and reducing the production cost of polypropylene. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:
[0012] Figure 1 The schematic diagram of the structure of the polypropylene preparation device provided in this embodiment is shown.
[0013] Reference numerals:
[0014] 100-propylene refining unit; 101-propylene storage tank; 102-dehydration tower; 103-desulfurization tower; 104-deoxygenation tower; 105-decarbon monoxide tower; 106-refined propylene storage tank; 200-polymerization reactor; 300-filtration flash drying reactor; 400-mixed solvent storage tank; 500-first condensation section; 600-compression unit; 601-gas cabinet; 602-compression section; 700-mixed solvent recovery unit; 701-waste liquid storage tank; 702-mixed solvent recovery tower; 703-feed pump; 704-bottom pump; 705-reboiling section; 706-second condensation section; 800-polypropylene granulation section. DETAILED DESCRIPTION
[0015] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0016] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.
[0017] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present disclosure.
[0018] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present disclosure should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.
[0019] In the present utility model, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or plural.
[0020] In view of the problems of great difficulty in operating the production of polypropylene, large consumption of washing solvents and high processing costs in the prior art, the embodiment of the utility model provides a polypropylene preparation device, which can improve the purity of polypropylene while shortening the production process of polypropylene and reducing production costs. Figure 1 The schematic diagram of the structure of the polypropylene preparation device provided in this embodiment is shown. Figure 1 As shown, the polypropylene preparation device comprises:
[0021] A propylene refining unit 100, a polymerization reactor 200, a filtration flash drying reactor 300 and a mixed solvent storage tank 400, wherein the outlet of the propylene refining unit 100 is connected to the feed port of the polymerization reactor 200, the product outlet of the polymerization reactor 200 is connected to the feed port of the filtration flash drying reactor 300, and the outlet of the mixed solvent storage tank 400 is connected to the liquid inlet of the filtration flash drying reactor 300.
[0022] The propylene refining unit 100 includes a propylene storage tank 101, a dehydration tower 102, a desulfurization tower 103, a deoxygenation tower 104, a decarbon monoxide removal tower 105, and a refined propylene storage tank 106. The outlet of the propylene storage tank 101 is connected to the inlet of the dehydration tower 102, the outlet of the dehydration tower 102 is connected to the inlet of the deoxygenation tower 104 through the desulfurization tower 103, the outlet of the deoxygenation tower 104 is connected to the inlet of the refined propylene storage tank 106 through the decarbon monoxide removal tower 105, and the outlet of the refined propylene storage tank 106 is connected to the feed port of the polymerization reactor 200.
[0023] In the specific implementation, the propylene refining unit 100 is first used to prepare refined propylene, and then the refined propylene is passed through the outlet of the propylene refining unit 100 into the feed port of the polymerization reactor 200, so that the refined propylene can fully undergo polymerization reaction in the polymerization reactor 200. The product obtained by the reaction enters the feed port of the filter flash drying kettle 300 through the product outlet of the polymerization reactor 200 for evaporation treatment and drying treatment to remove the unreacted propylene contained in the product, reduce the ash content in the product, and obtain a product with relatively high purity. Finally, the mixed solvent is passed through the outlet of the mixed solvent storage tank 400 into the liquid inlet of the filter flash drying kettle 300, so that the product is washed with the mixed solvent to dissolve the random substances in the product, thereby further reducing the ash content in the product, and separating the high-purity polypropylene product and residual impurities. The process is less difficult to operate and is conducive to industrial large-scale production of polypropylene. In addition, the polypropylene preparation device provided by the utility model can complete the washing treatment of the product without setting a washing tower. Compared with the washing tower, the consumption of the mixed solvent in the polypropylene preparation device provided by the utility model is lower, so that the ash content can be reduced, the purity of the polypropylene product can be ensured, the production process of polypropylene can be simplified, and the recycling cost and energy consumption of the mixed solvent can be reduced. It can be understood that the degree of polymerization reaction can be accelerated by using an auxiliary agent in the polymerization reaction. The auxiliary agent used can be introduced into the feed port of the polymerization reactor 200 to participate in the reaction together with the refined propylene, and can be adjusted according to the actual situation, and is not limited here.
[0024] Exemplary, since there are impurities in the unrefined propylene that are not conducive to the polymerization reaction, in order to reduce the probability of these impurities destroying the active center or adding to the polymerization chain, thereby affecting the polymerization reaction and affecting the product quality, it is necessary to refine the propylene in advance. Specifically, it is necessary to pass the propylene along the outlet of the propylene storage tank 101 into the inlet of the dehydration tower 102 to remove the moisture in the propylene. Then, the propylene is passed from the outlet of the dehydration tower 102 into the inlet of the desulfurization tower 103 to remove the sulfur element in the propylene. Then, the propylene is passed from the outlet of the desulfurization tower 103 into the inlet of the deoxygenation tower 104 to remove the oxygen element in the propylene. Next, the propylene is passed from the outlet of the deoxygenation tower 104 into the decarbon monoxide removal tower 105 to remove the carbon monoxide in the propylene and obtain refined propylene. Finally, the refined propylene is passed from the outlet of the decarbon monoxide removal tower 105 into the inlet of the refined propylene storage tank 106 for storage. When the water content, methanol content and oxygen content in the refined propylene are all below 0.5 mg / kg, and the total sulfur content and carbon monoxide content are all below 0.1 mg / kg, it is beneficial to ensure the smooth progress of the polymerization reaction. Before the polymerization reaction starts, the refined propylene is fed into the feed port of the polymerization reactor 200 along the outlet of the refined propylene storage tank 106.
[0025] Exemplarily, when the raw materials including refined propylene are added to the feed port of the polymerization reactor 200, the pressure of the polymerization reactor 200 can be set to 2.8-3.2 MPa, the heating temperature of the polymerization reactor 200 can be set to 70-80°C, and the polymerization can be continued for 1-3 hours, which is beneficial to improving the conversion rate of refined propylene.
[0026] Compared with the traditional slurry polymerization method which requires the use of multiple polymerization reactors for polymerization reactions, the preparation device provided in the utility model only requires one polymerization reactor to complete the polymerization reaction, which can not only shorten the reaction process but also reduce production costs and energy consumption.
[0027] In an optional manner, the polypropylene preparation device provided by the utility model also includes: a first condensation section 500, the propylene outlet of the polymerization reactor 200 is connected to the inlet of the refined propylene storage tank 106 through the first condensation section 500, and the propylene outlet of the filter flash drying reactor 300 is connected to the inlet of the refined propylene storage tank 106 through the first condensation section 500.
[0028] In specific implementation, after the polymerization reaction is completed, the unreacted propylene gas is passed from the propylene outlet of the polymerization reactor 200 to the first condensation section 500, and is liquefied in the first condensation section 500 and then re-passed into the inlet of the refined propylene storage tank 106, so as to be used for feeding in the polymerization reactor 200 next time. Similarly, when the first product generated by the polymerization reaction is subjected to evaporation treatment and drying treatment in the filter flash drying kettle 300, the unreacted propylene gas separated from the product is passed through the propylene outlet of the filter flash drying kettle 300 and passed into the first condensation section 500, and can be liquefied into unreacted propylene liquid under the action of the first condensation section 500, and then, the unreacted propylene liquid can be re-passed into the inlet of the refined propylene storage tank 106 through the outlet of the first condensation section 500, so as to be used for feeding in the polymerization reactor 200 next time.
[0029] Exemplarily, when the product is subjected to evaporation and drying treatment, the pressure of the filtration flash drying kettle 300 can be set to 0.1-0.5 MPa. Compared with the pressure of the polymerization reactor 200, the pressure of the filtration flash drying kettle 300 is lower. Therefore, the pressure of the unreacted propylene gas separated from the propylene outlet of the filtration flash drying kettle 300 is lower. At this time, it is necessary to perform a pressurization operation on it before it can be reused. Based on this, the polypropylene preparation device provided by the utility model also includes: a compression unit 600, which is arranged between the propylene outlet of the filtration flash drying kettle 300 and the inlet of the first condensation section 500; the compression unit 600 includes a gas cabinet 601 and a compression section 602, and the gas cabinet 601 and the compression section 602 are sequentially connected in series between the propylene outlet of the filtration flash drying kettle 300 and the inlet of the first condensation section 500.
[0030] In specific implementation, after the product generated by the polymerization reaction is evaporated and dried in the filter flash drying kettle 300, the unreacted propylene gas separated from the product can be first passed from the propylene outlet of the filter flash drying kettle 300 into the inlet of the gas cabinet 601 for storage, and then the unreacted propylene gas is passed from the outlet of the gas cabinet 601 into the compression part 602 for pressurization, and then the pressurized propylene gas is passed from the outlet of the compression part 602 into the inlet of the first condensation part 500 for condensation treatment, and the liquefied propylene is re-introduced into the inlet of the refined propylene storage tank 106 to be used for feeding into the polymerization reactor 200 next time.
[0031] In an optional manner, the polypropylene preparation device provided by the utility model further includes: a mixed solvent recovery unit 700, the waste liquid outlet of the filtration flash drying kettle 300 is connected to the inlet of the mixed solvent recovery unit 700, and the outlet of the mixed solvent recovery unit 700 is connected to the liquid inlet of the filtration flash drying kettle 300 through the mixed solvent storage tank 400. Wherein, the mixed solvent recovery unit 700 includes a waste liquid storage tank 701 and a mixed solvent recovery tower 702, the waste liquid outlet of the filtration flash drying kettle 300 is connected to the inlet of the mixed solvent recovery tower 702 through the waste liquid storage tank 701, and the outlet of the mixed solvent recovery tower 702 is connected to the liquid inlet of the filtration flash drying kettle 300 through the mixed solvent storage tank 400.
[0032] It is understandable that when the washing treatment of the second product is completed, the washing waste liquid will enter the inlet of the waste liquid storage tank 701 from the waste liquid outlet of the filter flash drying kettle 300 for storage. In order to improve the liquid transmission effect, the mixed solvent recovery unit 700 in the embodiment of the utility model can also include a feed pump 703, which is arranged between the outlet of the waste liquid storage tank 701 and the inlet of the mixed solvent recovery tower 702. Therefore, when the washing waste liquid flows out from the outlet of the waste liquid storage tank 701, it can be passed into the inlet of the mixed solvent recovery tower 702 for recovery treatment under the action of the feed pump 703.
[0033] In addition, in the mixed solvent recovery tower 702, the impurities of the heavy component will move in the direction close to the bottom of the mixed solvent recovery tower 702. In order to improve the recovery effect of the mixed solvent, the mixed solvent recovery unit 700 in the embodiment of the utility model can also include a tower bottom pump 704 and a reboiling part 705, wherein the tower bottom pump 704 and the reboiling part 705 are sequentially connected in series between the first heavy component outlet of the mixed solvent recovery tower 702 and the first heavy component inlet of the mixed solvent recovery tower 702, and the second heavy component outlet of the mixed solvent recovery tower 702 is a waste discharge port.
[0034] For example: when the mixed solvent recovery tower 702 treats the washing waste liquid, under the action of the tower bottom pump 704, the heavy component waste liquid can enter the reboiling section 705 from the heavy component outlet of the mixed solvent recovery tower 702 to vaporize the heavy component waste liquid multiple times, and finally separate the waste material without mixed solvent gas, which can be discharged to the underground waste oil tank along the second heavy component outlet of the mixed solvent recovery tower 702 and discharged manually on a regular basis.
[0035] In the mixed solvent recovery tower 702, the mixed solvent gas of the light component can move in the direction of the tower top near the mixed solvent recovery tower 702. In order to improve the recovery effect of the mixed solvent, the mixed solvent recovery unit 700 in the embodiment of the utility model can also have a second condensing section 706, wherein the second condensing section 706 is arranged between the first light component outlet and the first light component inlet of the mixed solvent recovery tower 702 to condense and reflux. The mixed solvent gas obtained in this process is liquefied into a mixed solvent under the action of the second condensing section 706. The mixed solvent is then passed into the inlet of the mixed solvent storage tank 400 along the outlet of the second condensing section 706 for standby use. When the product is washed, the mixed solvent can be passed into the liquid inlet of the filter flash drying kettle 300 along the outlet of the mixed solvent storage tank 400.
[0036] In an optional manner, the polypropylene preparation device provided by the utility model further includes: a polypropylene granulation section 800 , and the product outlet of the filtration flash drying kettle 300 is connected to the inlet of the polypropylene granulation section 800 .
[0037] Specifically, the dried polypropylene product can be passed from the product outlet of the filter flash drying kettle 300 to the inlet of the polypropylene granulation unit 800 for granulation treatment to make the polypropylene product into polypropylene particles. The outlet of the polypropylene granulation unit can be provided with a metal filter of 1000-2000 meshes to filter out some insoluble solid oxides and reduce the ash content of the polypropylene particles.
[0038] It should be understood that the additives in the embodiments of the present invention can be selected according to actual needs and are not limited here.
[0039] The above is only a specific implementation of the utility model. Obviously, various modifications and combinations can be made to it without departing from the spirit and scope of the utility model. Accordingly, this specification and the drawings are only exemplary illustrations of the utility model defined by the attached claims, and are deemed to have covered any and all modifications, changes, combinations or equivalents within the scope of the utility model. Obviously, those skilled in the art can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and their equivalents, the utility model is intended to include these changes and variations. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be covered within the scope of protection of the utility model. Therefore, the scope of protection of the utility model shall be based on the scope of protection of the claims.
Claims
1. A polypropylene production device, characterized in that: The polypropylene preparation device comprises: A propylene refining unit, a polymerization reactor, a filtration flash drying reactor and a mixed solvent storage tank, wherein the outlet of the propylene refining unit is connected to the feed inlet of the polymerization reactor, the product outlet of the polymerization reactor is connected to the feed inlet of the filtration flash drying reactor, and the outlet of the mixed solvent storage tank is connected to the liquid inlet of the filtration flash drying reactor; Wherein, the propylene refining unit comprises a propylene storage tank, a dehydration tower, a desulfurization tower, a deoxygenation tower, a decarbon monoxide removal tower and a refined propylene storage tank; the outlet of the propylene storage tank is connected to the inlet of the dehydration tower, the outlet of the dehydration tower is connected to the inlet of the deoxygenation tower through the desulfurization tower, the outlet of the deoxygenation tower is connected to the inlet of the refined propylene storage tank through the decarbon monoxide removal tower, and the outlet of the refined propylene storage tank is connected to the feed port of the polymerization reactor.
2. The polypropylene preparation device according to claim 1, characterized in that: The polypropylene preparation device further includes: a first condensation section, through which the propylene outlet of the polymerization reactor is connected to the inlet of the refined propylene storage tank, and through which the propylene outlet of the filtration flash drying reactor is connected to the inlet of the refined propylene storage tank.
3. The polypropylene preparation device according to claim 2, characterized in that: The polypropylene preparation device also includes: a compression unit, which is arranged between the propylene outlet of the filtration flash drying kettle and the inlet of the first condensation section; the compression unit includes a gas cabinet and a compression section, and the gas cabinet and the compression section are sequentially connected in series between the propylene outlet of the filtration flash drying kettle and the inlet of the first condensation section.
4. The polypropylene production device according to any one of claims 1 to 3, characterized in that: The polypropylene preparation device also includes: a mixed solvent recovery unit, the waste liquid outlet of the filtration flash drying kettle is connected to the inlet of the mixed solvent recovery unit, and the outlet of the mixed solvent recovery unit is connected to the liquid inlet of the filtration flash drying kettle through the mixed solvent storage tank; the mixed solvent recovery unit includes a waste liquid storage tank and a mixed solvent recovery tower, the waste liquid outlet of the filtration flash drying kettle is connected to the inlet of the mixed solvent recovery tower through the waste liquid storage tank, and the outlet of the mixed solvent recovery tower is connected to the liquid inlet of the filtration flash drying kettle through the mixed solvent storage tank.
5. The polypropylene preparation device according to claim 4, characterized in that: The mixed solvent recovery unit further comprises a feed pump, which is arranged between the outlet of the waste liquid storage tank and the inlet of the mixed solvent recovery tower.
6. The polypropylene preparation device according to claim 4, characterized in that: The mixed solvent recovery unit also includes a bottom pump and a reboiling section; the bottom pump and the reboiling section are sequentially connected in series between the first heavy component outlet of the mixed solvent recovery tower and the first heavy component inlet of the mixed solvent recovery tower, and the second heavy component outlet of the mixed solvent recovery tower is a waste discharge port.
7. The polypropylene preparation device according to claim 4, characterized in that: The mixed solvent recovery unit also includes a second condensation section, which is arranged between the first light component outlet and the first light component inlet of the mixed solvent recovery tower, and the outlet of the second condensation section is connected to the liquid inlet of the filtration flash drying kettle through the mixed solvent storage tank.
8. The polypropylene preparation device according to claim 1, characterized in that: The polypropylene preparation device further comprises: a polypropylene granulation section; and the product outlet of the filtration flash drying kettle is connected to the inlet of the polypropylene granulation section.