A polymerization reactor and system

Abstract

This utility model discloses a polymerization reactor and system. The reactor includes a polymerization reaction section, an inactivation section, and a discharge section connected in sequence. The polymerization reaction section includes a shell and a meshing screw penetrating the shell, so that the material fed into the polymerization reaction section undergoes a polymerization reaction through the meshing rotation of the screw, and the resulting product is transported to the inactivation section. The inactivation section and the discharge section are hollow structures, with the screw penetrating the inactivation section and extending into the discharge section. The shell of the inactivation section is provided with an injection port for injecting a terminator into the inactivation section to inactivate the polymerization chain end-capping of the polymer product in the resulting product, and the resulting product after polymerization chain end-capping inactivation is transported to the discharge section through the meshing rotation of the screw. The shell of the discharge section is provided with a devolatilization port and a discharge port to remove unreacted materials and by-products from the resulting product and to discharge the polymerization product after polymerization chain end-capping inactivation. This polymerization reactor can improve the quality of the polymerization product.

Description

Technical Field

[0001] This utility model relates to the field of petrochemical technology, and in particular to a polymerization reactor and system. Background Technology

[0002] In the petrochemical industry, especially in the production of copolymerized formaldehyde, polymerization reactors are commonly used. Multiple streams of liquid materials required for the polymerization reaction enter the reactor and undergo copolymerization within the reactor, exiting as solid powder. After processes such as grinding, drying, melt extrusion, degassing, and granulation, the final product becomes copolymerized formaldehyde granules.

[0003] In the current mainstream copolymer polyoxymethylene (POM) production process, the monomers, chain transfer agents, and catalysts required for the polymerization reaction are fed into the polymerization reactor via metering pumps and a feed mixer. The polymerization reaction occurs within the reactor, and the liquid phase gradually increases in viscosity, becoming a paste, and finally, copolymer polyoxymethylene powder. This powder is discharged from the reactor, ground in a grinder, and then enters a screw conveyor. The screw conveyor is typically a long-distance single-screw conveyor. A nozzle is installed at the top of the conveyor cylinder to spray a terminator onto the polymer powder, thereby inactivating the polymer's active centers and sealing the polymer chains, thus ending the polymerization reaction. The grinding of the polymer product before it is conveyed to the screw conveyor primarily serves to break up any agglomerated polymer products, preventing uneven contact between the polymer product and the terminator due to clumping.

[0004] Because polymerization reactions have a certain conversion rate, the injected monomer material cannot fully participate in the reaction. Some unreacted monomers adhere to the surface of the polyoxymethylene (POM) powder. Therefore, in existing technologies, during the process of conveying POM powder from the polymerization reactor to the screw conveyor, localized polymerization reactions continue, leading to inconsistent polymer chain lengths and a wide molecular weight distribution range, resulting in a decline in the performance of the POM product. Therefore, improving the quality of POM products is a pressing issue that needs to be addressed in current technologies. Utility Model Content

[0005] In view of the above problems, the present invention is proposed to provide a polymerization reactor and system that overcomes or at least partially solves the above problems.

[0006] In a first aspect, this utility model provides a polymerization reactor, comprising: a polymerization reaction section, an inactivation section, and a discharge section connected in sequence;

[0007] The polymerization reaction section includes a shell and intermeshing screws penetrating the shell, so that the material transported to the polymerization reaction section undergoes a polymerization reaction through the intermeshing rotation of the screws, and the resulting product is transported to the inactivation section. The resulting product includes: polymerization product, unreacted material and by-products.

[0008] The inactivation section and the discharge section are hollow structures, and the screw passes through the inactivation section and extends into the discharge section;

[0009] The shell of the inactivation section is provided with an injection port to inject a terminator into the inactivation section through the injection port to inactivate the polymerization product by end-capping the polymerization chain, and the resulting product after end-capping the polymerization chain is transported to the discharge section by the meshing and rotation of the screw.

[0010] The shell of the discharge section is provided with a devolatilization port and a discharge port. The devolatilization port is used to remove the unreacted materials and by-products; the discharge port is used to discharge the polymer products after the polymer chain is capped and deactivated.

[0011] In an optional embodiment, the injection port is configured as one or more;

[0012] When multiple injection ports are provided, the injection ports are circumferentially spaced on the shell of the inactivation section.

[0013] In an optional embodiment, the devolatilization port is configured as one or more;

[0014] When multiple devouring ports are provided, the devouring ports are distributed axially at intervals on the shell of the discharge section.

[0015] In an optional embodiment, the devolatilization port is located at the top of the discharge section housing, and the discharge outlet is located at the bottom of the discharge section housing.

[0016] In an optional embodiment, the polymerization reactor provided by the present invention further includes: a feed mixer;

[0017] The feed mixer is installed on the wall of the polymerization reactor housing and is connected to the feed end of the polymerization reaction section to mix the materials required for the polymerization reaction and input the mixed materials into the polymerization reaction section housing.

[0018] In one optional embodiment, the polymerization reaction section shell, the inactivation section shell, and the discharge section shell are integrally formed structures or separate formed structures.

[0019] In an optional embodiment, if the polymerization reaction section shell, the inactivation section shell, and the discharge section shell are separate structures, the shells are connected by bolts.

[0020] In an optional embodiment, the screw includes a forward conveying screw block section, a shearing conveying screw block section, a shearing screw block section, and a reverse conveying spiral section arranged sequentially.

[0021] The forward conveying screw block section, the shearing conveying screw block section, and a portion thereof are disposed within the polymerization reaction section shell, and another portion thereof penetrates the inactivation section and extends into the discharge section shell.

[0022] The reverse conveying spiral section is located at one end of the screw that extends into the discharge section.

[0023] In an optional embodiment, the polymerization reactor provided by the present invention further includes: a vacuum system;

[0024] The vacuum system is connected to the devolatilization port to provide a vacuum environment for the devolatilization port.

[0025] Based on the same inventive concept, embodiments of the present invention also provide a polymerization reaction system including the above-described polymerization reactor.

[0026] The beneficial effects of the above-mentioned technical solutions provided by the embodiments of this utility model include at least the following:

[0027] This invention provides a polymerization reactor and system. The reactor includes an inactivation section and a discharge section after the polymerization reaction section. This moves the polymer end-capping and inactivation process forward in the polymerization product production flow, allowing the addition of a terminator immediately after the polymerization reaction and product generation to inactivate the polymer. This results in a more uniform and consistent increase in the polymer's molecular chain size, narrowing the molecular weight distribution range. Furthermore, the reactor features intermeshing screws extending from the polymerization reaction section to the discharge section. These screws facilitate the transport, mixing, and shearing of reactants, meeting the requirements of the polymerization reaction. Simultaneously, the resulting polymer products are transported forward to the inactivation section for end-capping and inactivation. During the screw's rotation, the terminator mixes evenly with the polymer, enhancing the end-capping and inactivation effect. Simultaneously, a devolatilization port is added above the discharge section. This port allows for the timely removal of lighter unreacted materials and byproducts—residual low-molecular-weight volatile components—preventing these substances from adhering to the surface of the polymerization product and entering subsequent processes. This reduces the content of unreacted materials and byproducts in the polymerization product, thereby improving product quality. In other words, the polymerization reactor provided in this embodiment can complete the polymerization reaction, end-capping and inactivation of the polymerization product, and removal of unreacted materials, effectively improving the quality of the produced polymerization product.

[0028] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0029] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 This is a schematic diagram of the polymerization reactor in an embodiment of the present invention;

[0032] Figure 2 This is a top view of the polymerization reactor in an embodiment of this utility model;

[0033] Figure 3 This is a cross-sectional view of the polymerization reactor in an embodiment of this utility model.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100, Feed mixer; 200, Polymerization reaction section; 300, Deactivation section; 400, Discharge section; 500, Screw; 301, Injection port; 401, Deviation port; 402, Discharge port; 501, Forward conveying screw section; 502, Shearing conveying screw section; 503, Shearing screw section; 504, Reverse conveying screw section. Detailed Implementation

[0036] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0037] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0039] To address the problems of low polymerization conversion rate, wide molecular weight distribution range of polyoxymethylene, and unstable end groups caused by uneven contact between the terminator and powder in existing polymerization reaction processes, this utility model provides a polymerization reactor and system.

[0040] It should be noted that in this embodiment... Figures 1 to 3 The diagram illustrates, only by way of example, the structure of a polymerization reactor for producing copolyoxymethylene. Some structures are represented by lines, which are merely illustrative and do not represent actual shapes. Furthermore, the polymerization reactor provided in this embodiment can be used for polymerization reactions of various substances to produce various polymerization products, including but not limited to those used for producing copolyoxymethylene.

[0041] The polymerization reactor provided in this embodiment of the present invention refers to... Figures 1 to 3 As shown, it includes: a polymerization reaction section 200, an inactivation section 300, and a discharge section 400 connected in sequence;

[0042] The polymerization reaction section 200 includes a shell and a meshing screw 500 penetrating the shell, so that the material conveyed to the polymerization reaction section 200 undergoes a polymerization reaction through the meshing rotation of the screw 500, and the resulting product is conveyed to the inactivation section 300. The resulting product includes: polymerization product, unreacted material and by-product.

[0043] The inactivation section 300 and the discharge section 400 are hollow structures, and the screw 500 passes through the inactivation section 300 and extends into the discharge section 400;

[0044] The shell of the inactivation section 300 is provided with an injection port 301 to inject a terminator into the inactivation section 300 through the injection port 301 to inactivate the polymerization product by end-capping the polymerization chain, and the resulting product after end-capping the polymerization chain is conveyed to the discharge section 400 by the meshing and rotation of the screw 500.

[0045] The discharge section 400 is provided with a devolatilization port 401 and a discharge port 402 on its shell. The devolatilization port 401 is used to remove unreacted materials and by-products; the discharge port 402 is used to discharge the polymer products after the polymer chain is capped and inactivated.

[0046] Among them, byproducts are mainly substances other than the desired polymerization product generated in the polymerization reaction, which are generally some small molecule volatile components; for example, in the production of copolymerized formaldehyde, byproducts include formaldehyde that has separated from the reactants or is generated in the polymerization reaction.

[0047] It should be noted that this utility model does not specifically limit the specific length and proportional relationship of each section in the polymerization reactor provided in this embodiment. It can be selected according to actual needs. For example, it can be designed according to the different residence time requirements of materials or products in each section. Specifically, when the materials need to react in the polymerization reaction section for a longer time to ensure that the materials fully undergo the polymerization reaction, the length of the polymerization reaction section can be increased to meet the corresponding requirements. The same applies to other sections.

[0048] In one embodiment, the polymerization reactor provided by this utility model may have one or more injection ports 301;

[0049] When multiple injection ports 301 are provided, the injection ports 301 are circumferentially spaced on the shell of the inactivation section 300 so that when the terminator is injected into the inactivation section 300, it can be injected from different directions to better contact the terminator with the polymerization product.

[0050] In an optional embodiment, the volatilization port 401 is configured as one or more;

[0051] When multiple devolatilization ports 401 are provided, the devolatilization ports 401 are distributed axially at intervals on the shell of the discharge section 400. By providing multiple devolatilization ports 401 distributed axially at intervals along the discharge section 400, multiple discharge channels can be provided for unreacted materials. This allows unreacted materials to be discharged through other devolatilization ports 401 even if they are not discharged through the first devolatilization port 401 near the end of the inactivation section 300, thereby improving the efficiency of unreacted materials being removed from the polymerization reactor.

[0052] In practical applications, in order to better extract unreacted materials from the polymerization reactor, the devolatilization port 401 can be specifically connected to a vacuum system to provide conditions for the extraction of unreacted materials through the vacuum system.

[0053] Furthermore, during the design process, the vacuum system can be part of the polymerization reactor or a separate device distinct from the polymerization reactor. This embodiment of the present invention does not specifically limit this. In one optional embodiment, the polymerization reactor provided by this embodiment of the present invention may further include: a vacuum system connected to the devolatilization port 401; and in practical applications, the vacuum conditions can be set according to the weight difference between unreacted materials and by-products and polymerization products, so that when the vacuum system is used for extraction, the above-mentioned substances are extracted while the polymerization products remain in the polymerization reactor.

[0054] In one embodiment, to facilitate the discharge of unreacted materials and byproducts, the devolatilization port 401 of the polymerization reactor is located at the top of the discharge section 400 shell; and to facilitate the discharge of the polymerization product after end-capping and inactivation of the polymerization chain from the polymerization reactor and into subsequent processing steps, the discharge port 402 is located at the bottom of the discharge section 400 shell.

[0055] Optional, refer to Figures 1 to 3 As shown, the polymerization reactor provided in this embodiment of the present invention may further include: a feed mixer 100;

[0056] The feed mixer 100 is installed on the wall of the polymerization reactor housing and is connected to the feed end of the polymerization reaction section to mix the materials required for the polymerization reaction and input the mixed materials into the polymerization reaction section housing.

[0057] Optionally, in the polymerization reactor, the polymerization reaction section shell, the inactivation section shell, and the discharge section shell can be configured as an integrally formed structure, such as... Figure 3 As shown; or configured as a split-type molding structure, such as Figure 1 and Figure 2 As shown, this embodiment of the utility model does not impose specific limitations on this aspect, and can be selected according to actual needs.

[0058] Furthermore, in the case where the polymerization reaction section shell, the inactivation section shell, and the discharge section shell of the polymerization reactor provided in this embodiment of the present invention are set as separate structures, the shells can be connected by bolts. That is, the polymerization reactor of this embodiment of the present invention can be set as a segmented design, and the segments can be connected by bolts. In this case, the processed segments can be combined and replaced according to the requirements of different residence times, so as to reduce processing costs or facilitate maintenance and replacement.

[0059] In one embodiment, the polymerization reactor provided by this utility model, with reference to Figure 3 As shown, the screw 500 includes a forward conveying screw block section 501, a shearing conveying screw block section 502, a shearing screw block section 503, and a reverse conveying screw section 504 arranged sequentially.

[0060] A portion of the forward conveying screw block section 501, the shearing conveying screw block section 502, and the shearing screw block section 503 are disposed within the polymerization reaction section housing. Another portion of the shearing screw block section 503 penetrates the inactivation section 300 and extends into the discharge section 400 housing. The reverse conveying screw section 504 is disposed at one end of the screw 500 that extends into the discharge section 400.

[0061] In this embodiment of the invention, the screw 500 of the polymerization reactor is configured as a kneading twin-screw, using a combination of multi-head kneading toothed screw blocks of different forms. This achieves the conveying, mixing, and shearing of the reactants in the polymerization reaction section to meet the requirements of the polymerization reaction. Specifically, in the polymerization reaction section, because the materials enter the reactor in a liquid mixed state, the forward conveying screw block section 501 mainly serves to propel the fluid forward. At this stage, the reactants begin to react and form a paste-like substance, which then enters the shearing conveying screw block section 502. The paste becomes increasingly viscous as it progresses until it forms a powder. At this point, it needs to be compressed in the shearing screw block section 503. Under the compression action, the molecular chains further migrate towards the active center chain ends, achieving continuous molecular chain growth. The inactivation section is configured as the shearing screw block section 503, which uses shearing action to compress and mix the materials, ensuring that the powdered polymerization product and the terminator are fully mixed, thereby inactivating the polymerization chain. Furthermore, a reverse conveying spiral section 504 is set at the end of the screw 500. On the one hand, it pushes the polymerization product in the opposite direction, which is conducive to discharge. On the other hand, it can prevent the polymerization product from accumulating at the end of the discharge section 400 and forming a discharge dead zone. This makes it easier for the polymerization product to be discharged from the discharge port of the polymerization reactor and discharged into the subsequent processing steps.

[0062] Based on the same inventive concept, this utility model also provides a polymerization reaction system including the above-mentioned polymerization reactor.

[0063] The polymerization reactor and system provided in this embodiment include a polymerization reaction section, an inactivation section, and a discharge section. The inactivation section has an injection port where a terminator is injected into the powder after the polymerization reaction. Under the mixing action of a twin-screw extruder, the terminator and the polymerization product are fully mixed to achieve chain end-capping and inactivation. The discharge section has a devolatilization port to effectively remove unreacted monomers and other small molecule byproducts adhering to the surface of the polymerization product, thereby improving the quality of the polymerization product. In other words, by injecting a terminator into the reaction product in the inactivation section, this polymerization reactor effectively reduces the problems of inconsistent chain lengths and wide molecular weight distribution ranges caused by the late injection of the terminator in existing polymerization reactors, where chain growth and chain transfer occur continuously during material transport. Furthermore, in this embodiment, injecting the terminator in the twin-screw kneading zone of the inactivation section allows for sufficient contact between the polymerization product and the terminator, inactivating the active centers of the polymerization chain and solving the problem of wide molecular weight distribution ranges in the polymerization product. By setting a devolatilization port in the discharge section, unreacted materials and byproducts can be extracted from the polymerization reactor through vacuum, effectively removing the aforementioned substances adhering to the surface of the powder, reducing the content of unreacted materials and byproducts in the polymerization product, and thus improving product quality.

[0064] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0065] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the present invention is in a state with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the present invention.

[0066] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A polymerization reactor characterized in that, include: The polymerization reaction section, the inactivation section, and the discharge section are connected in sequence; The polymerization reaction section includes a shell and intermeshing screws penetrating the shell, so that the material transported to the polymerization reaction section undergoes a polymerization reaction through the intermeshing rotation of the screws, and the resulting product is transported to the inactivation section. The resulting product includes: polymerization product, unreacted material and by-products. The inactivation section and the discharge section are hollow structures, and the screw passes through the inactivation section and extends into the discharge section; The shell of the inactivation section is provided with an injection port to inject a terminator into the inactivation section through the injection port to inactivate the polymerization product by end-capping the polymerization chain, and the resulting product after end-capping the polymerization chain is transported to the discharge section by the meshing and rotation of the screw. The shell of the discharge section is provided with a devolatilization port and a discharge port. The devolatilization port is used to remove the unreacted materials and by-products; the discharge port is used to discharge the polymer products after the polymer chain is capped and deactivated.

2. The polymerization reactor as described in claim 1, characterized in that, The injection port is configured as one or more; When multiple injection ports are provided, the injection ports are circumferentially spaced on the shell of the inactivation section.

3. The polymerization reactor as described in claim 1, characterized in that, The devolatilization port is configured as one or more; When multiple devouring ports are provided, the devouring ports are distributed axially at intervals on the shell of the discharge section.

4. The polymerization reactor as described in claim 1, characterized in that, The devolatilization port is located at the top of the discharge section shell, and the discharge port is located at the bottom of the discharge section shell.

5. The polymerization reactor as described in claim 1, characterized in that, Also includes: Feed mixer; The feed mixer is installed on the wall of the polymerization reactor housing and is connected to the feed end of the polymerization reaction section to mix the materials required for the polymerization reaction and input the mixed materials into the polymerization reaction section housing.

6. The polymerization reactor as described in claim 1, characterized in that, The polymerization reaction section shell, the inactivation section shell, and the discharge section shell are either integrally formed or separately formed.

7. The polymerization reactor as described in claim 1, characterized in that, When the polymerization reaction section shell, the inactivation section shell, and the discharge section shell are separate structures, the shells are connected by bolts.

8. The polymerization reactor as described in claim 1, characterized in that, The screw includes a forward conveying screw block section, a shearing conveying screw block section, a shearing screw block section, and a reverse conveying spiral section arranged in sequence. The forward conveying screw block section, the shearing conveying screw block section, and a portion thereof are disposed within the polymerization reaction section shell, and another portion thereof penetrates the inactivation section and extends into the discharge section shell. The reverse conveying spiral section is located at one end of the screw that extends into the discharge section.

9. The polymerization reactor according to any one of claims 1-8, characterized in that, Also includes: Vacuum system; The vacuum system is connected to the devolatilization port to provide a vacuum environment for the devolatilization port.

10. A polymerization reaction system, characterized in that, Includes the polymerization reactor as described in any one of claims 1-9.

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