Systems and techniques for polymer product withdrawal

Abstract

A down-flow polymer product extraction system includes an extraction line for collecting a product comprising a powder and a carrier gas. The line may include at least one downwardly inclined descent section, and there is no non-self-discharging area. The down-flow system may also include a lockout hopper, a fill valve located between the line and the lockout hopper, and a drain valve located downstream of the lockout hopper. An up-flow polymer product extraction system includes an extraction line for collecting and discharging a product comprising a powder and a carrier gas. The pipeline can comprise at least one non-vertical section, and the at least one non-vertical section comprises at least one upward inclined ascending section and at least one downward inclined descending section; and no non-self-discharging area exists. The up-flow system may also include a lockout hopper, a fill valve between the line and the lockout hopper, and a drain valve.

Description

[0001] Cross - reference to related applications

[0002] None. Technical field

[0003] The present disclosure relates to systems and techniques for polymerization, and in particular, to systems and techniques for withdrawing polymer products from a polymerization reactor. Background art

[0004] Single - reactor or multi - reactor systems can be used to produce polymer resins, such as polyethylene. For example, a loop slurry reactor or a gas - phase reactor can be used to produce polyethylene. The product stream includes polymer flakes or pellets and a reaction fluid. In continuous polymer production, it is desirable to selectively increase the ratio of the polymer product relative to the reaction fluid and to substantially return the withdrawn reaction fluid to the reactor while maintaining a high withdrawal density and rate. It is also desirable to reduce the complexity and number of components in the polymer product withdrawal system.

[0005] There is still a need for new and improved systems and methods for polymer reactor product withdrawal. Summary of the invention

[0006] This summary of the invention is provided to introduce various concepts in a simplified form that will be further described in the detailed description below. This summary of the invention is not intended to identify essential or necessary features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0007] In various aspects, the present disclosure describes a down - flow polymer product withdrawal system. The system includes a withdrawal line coupled to and downstream of a reactor outlet, the reactor outlet being configured to collect and discharge a product comprising powder and a carrier gas. The withdrawal line defines a down - flow volume. The withdrawal line includes at least one downwardly inclined descent section. The withdrawal line has no non - self - discharging regions. The system further includes a lock hopper coupled to the withdrawal line and downstream of the withdrawal line. The lock hopper defines a chamber configured to receive at least a portion of the powder and the carrier gas from the withdrawal line. The system further includes a fill valve located between the withdrawal line and the lock hopper, and a discharge valve located downstream of the lock hopper.

[0008] In various aspects, the present disclosure describes a polymerization system that includes a polymerization reactor having a reactor outlet configured to discharge a product comprising powder and a carrier gas. The powder includes a polymer. The polymerization system further includes a down - flow polymer product withdrawal system coupled to the reactor outlet.

[0009] In various aspects, the present disclosure describes techniques for operating an aggregation system that includes an aggregation reactor and a downflow polymer product withdrawal system coupled to the reactor outlet of the aggregation reactor. The techniques include opening a fill valve of the downflow polymer product withdrawal system to fluidly couple a lock hopper to the aggregation reactor through a withdrawal line. The withdrawal line includes at least one downwardly inclined section. There are no non-self-draining regions in the withdrawal line. The techniques also include, after opening the fill valve, receiving a plug containing powder and gas from the withdrawal line into the lock hopper. The techniques also include, after receiving the plug, allowing the lock hopper to be pressurized to the reactor pressure with gas received from the reactor through the withdrawal line. The techniques also include, after pressurization, allowing powder from the withdrawal line to continue to settle into the lock hopper for a predetermined settling time. The techniques also include, after settling, closing the fill valve to isolate the lock hopper from the withdrawal line and the reactor. The techniques also include, after closing the fill valve, opening a discharge valve to discharge the contents of the lock hopper.

[0010] In various aspects, the present disclosure describes an upflow polymer product withdrawal system. The system includes a withdrawal line coupled to and downstream of a reactor outlet configured to collect and discharge a product containing powder and a carrier gas. The withdrawal line defines an upflow volume. The withdrawal line includes at least one non-vertical section. The non-vertical section includes at least one upwardly inclined section and at least one downwardly inclined section. The upwardly inclined section is downstream of the reactor. The downwardly inclined section is downstream of the upwardly inclined section. There are no non-self-draining regions in the withdrawal line. The system also includes a lock hopper coupled to at least one downwardly inclined section of the withdrawal line and downstream of the at least one downwardly inclined section. The lock hopper defines a chamber configured to receive at least a portion of the powder and carrier gas from the withdrawal line. The system also includes a fill valve located between the withdrawal line and the lock hopper, and a discharge valve downstream of the lock hopper.

[0011] In various aspects, the present disclosure describes an aggregation system that includes an aggregation reactor having a reactor outlet configured to discharge a product containing powder and a carrier gas. The powder includes a polymer. The system includes an upflow polymer product withdrawal system coupled to the reactor outlet.

[0012] In various aspects, the present disclosure describes techniques for operating an aggregation system that includes an aggregation reactor and an upflow polymer product withdrawal system coupled to the reactor outlet of the aggregation reactor. The techniques include opening a fill valve of the upflow polymer product withdrawal system to fluidly couple a lock hopper of the upflow polymer product withdrawal system to the reactor via a withdrawal line. The withdrawal line includes at least one non-vertical section. The at least one non-vertical section includes at least one upwardly inclined riser section and at least one downwardly inclined downcomer section. There are no non-self-draining regions in the withdrawal line. The techniques further include, after opening the fill valve, receiving a mixture of powder and gas from the withdrawal line into the lock hopper and allowing the lock hopper to be pressurized to the reactor pressure. The techniques further include, after pressurization, allowing powder from the withdrawal line to continue to settle into the lock hopper for a predetermined settling time. The techniques further include, after settling, closing the fill valve and an equalization valve along at least one upwardly inclined section of the withdrawal line to isolate the lock hopper from the withdrawal line and the reactor. The techniques further include, after closing the fill valve, opening a discharge valve to discharge the contents of the lock hopper.

[0013] This summary and the following detailed description provide examples and are merely illustrative of the present disclosure. Accordingly, the foregoing summary and the following detailed description should not be considered restrictive. Additional features or variations thereof may be provided in addition to the features set forth herein, such as various feature combinations and sub-combinations of the features described in the detailed description, for example. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following drawings form a part of the present disclosure and are included to further illustrate certain aspects of the present invention. The present invention can be better understood by referring to one or more of these drawings in combination with the detailed description of the specific embodiments given herein.

[0015] Figure 1 is a conceptual block diagram showing an aggregation system that includes a downflow polymer product withdrawal system coupled to an aggregation reactor.

[0016] Figures 2A to 2F is a conceptual diagram showing different stages of product withdrawal in a downflow polymer product withdrawal system. Figure 2A is a conceptual diagram illustrating the system in an initial configuration. Figure 2B is a conceptual diagram illustrating the system in an intermediate plunger release configuration. Figure 2C is a conceptual diagram illustrating the system in an intermediate pressurization configuration. Figure 2D is a conceptual diagram illustrating the system in an intermediate solid settlement configuration. Figure 2E is a conceptual diagram illustrating the system in an intermediate solid release configuration. Figure 2F is a conceptual diagram illustrating the system in a final evacuation configuration.

[0017] Figure 3 is a flow chart showing a technique for withdrawing a polymer product using a downflow polymer product withdrawal system coupled to a polymerization reactor.

[0018] Figure 4 is a conceptual block diagram showing a polymerization system that includes an upflow polymer product withdrawal system coupled to a polymerization reactor.

[0019] Figures 5A to 5D is a conceptual diagram showing different stages of product withdrawal in an upflow polymer product withdrawal system. Figure 5A is a conceptual diagram illustrating the system in an initial configuration. Figure 5B is a conceptual diagram illustrating the system in an intermediate pressurized configuration. Figure 5C is a conceptual diagram illustrating the system in an intermediate settling configuration. Figure 5D is a conceptual diagram illustrating the system in a final evacuation configuration.

[0020] Figure 6 is a flow chart showing a technique for withdrawing a polymer product using an upflow polymer product withdrawal system coupled to a polymerization reactor.

[0021] Figure 7 is a conceptual block diagram showing a polymerization system that includes a fluidized upflow polymer product withdrawal system coupled to a polymerization reactor.

[0022] Figures 8A to 8C is a conceptual diagram showing different stages of product withdrawal in a fluidized upflow polymer product withdrawal system. Figure 8A is a conceptual diagram illustrating the system in a fluidized configuration. Figure 8B is a conceptual diagram illustrating the system in an intermediate settling configuration. Figure 8C is a conceptual diagram illustrating the system in a discharge configuration.

[0023] Figure 9 is a flow chart showing a technique for withdrawing a polymer product using a fluidized upflow polymer product withdrawal system coupled to a polymerization reactor.

[0024] Figure 10 is a conceptual block diagram showing a polymerization system that includes a continuous output polymer product withdrawal system coupled to a polymerization reactor.

[0025] Figure 11 is an image showing a partial view of a continuous output valve in a continuous output polymer product withdrawal system.

[0026] Figure 12It is a conceptual diagram showing an intermediate stage of product extraction in a continuous output polymer product extraction system.

[0027] Figure 13 It is a flowchart showing a technique for extracting a polymer product using a continuous output polymer product extraction system coupled to a polymerization reactor.

[0028] Figure 14 It is a conceptual block diagram showing a polymerization system that includes a rotating cup polymer product extraction system coupled to a polymerization reactor.

[0029] Figure 15A and Figure 15B It is a conceptual diagram showing different stages of product extraction in a rotating cup polymer product extraction system. Figure 15A It is a conceptual diagram showing a rotating cup in a receiving configuration. Figure 15B It is a conceptual diagram showing a rotating cup in a discharge configuration.

[0030] Figure 16 It is a flowchart showing a technique for extracting a polymer product using a rotating cup polymer product extraction system coupled to a polymerization reactor.

[0031] Although the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific aspects have been shown by way of example in the drawings and are described in detail below. The drawings and the detailed description of these specific aspects are not intended in any way to limit the concept of the invention or the breadth or scope of the appended claims. Instead, the drawings and the detailed written description are provided to illustrate the concept of the invention to those of ordinary skill in the art and to enable such persons to obtain and use the concept of the invention. Detailed Description

[0032] It should be understood that the present disclosure is not limited in its application to the details of the construction and arrangement of components set forth in the following description or illustrated in the drawings.

[0033] Definitions

[0034] To more clearly define the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions apply to the present disclosure. If a term is used in the present disclosure but not specifically defined herein, then the definitions in the IUPAC Compendium of Chemical Terminology, 2nd Edition (1997) may be applied, provided that such definitions do not conflict with any other disclosure or definition applied herein or render any technical solution to which such definitions are applied unclear or invalid. If any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided herein, then the definition or usage provided herein shall prevail.

[0035] Although the compositions and techniques are described in terms of "comprising" various components or steps, unless otherwise specified, the compositions and techniques may also "consist essentially of" or "consist of" the various components or steps.

[0036] The terms "a" and "the" are intended to include plural alternatives, such as at least one. Unless otherwise indicated, the terms "comprising", "carrying" and "having" as used herein are defined as inclusive (i.e., open-ended language).

[0037] Various numerical ranges are disclosed herein. When the applicant discloses or claims any type of range, unless otherwise indicated, the applicant intends to disclose or claim separately each possible number that such range can reasonably cover, including the endpoints of the range and any sub-ranges and combinations of sub-ranges covered therein. For example, all numerical endpoints of the ranges disclosed herein are approximate, unless excluded by an accompanying condition.

[0038] Values or ranges may be expressed herein as "about", e.g., from "about" a particular value and / or to "about" another particular value. When expressing such values or ranges, other disclosed embodiments include the specific values, from one particular value and / or to another particular value. Similarly, when a value is expressed as an approximation by using the antecedent "about", it should be understood that the specific value forms another embodiment. Further, it should be understood that many values are disclosed herein, and each value is also disclosed herein as "about" the particular value in addition to the value itself. On the other hand, the use of the term "about" means ±20%, ±15%, ±10%, ±5%, ±3% or ±1% of the value.

[0039] Accordingly, if the applicant for any reason chooses to claim less than the full measure of the disclosure, such as considering references that the applicant may not have known at the time of filing the application, then the applicant reserves the right to specify or exclude any such individual member of any such group of values or ranges (including any sub-range or combination of sub-ranges within the group) that can be claimed according to the range or in any similar manner. In addition, if the applicant for any reason (such as considering references that the applicant may not have known at the time of filing the present application) chooses to claim less than the full measure of the present disclosure, then the applicant reserves the right to excise or exclude any individual substituent, analogue, compound, ligand, structure or group thereof, or any member of the claimed group.

[0040] For the purposes of this disclosure, a "self-draining region" is a region of a pipe, conduit or vessel through which the passing flow is completely drained under the action of gravity and in which, after closing the fill valve of the product withdrawal system, substantially no residual flow components are present in the self-draining region.

[0041] For the purposes of the present disclosure, a "non-self-draining region" is a region of a pipe, conduit, or vessel through which a passing stream is not completely drained under the action of gravity and in which at least some residual stream components persist after closing a fill valve of a product withdrawal system.

[0042] Although any techniques and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, typical techniques and materials are described herein.

[0043] All publications and patents mentioned herein are incorporated herein by reference for the purpose of describing and disclosing, for example, the constructs and methods described in the publications, which constructs and methods may be used in conjunction with the presently described invention. The publications discussed throughout the text are provided only for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.

[0044] The present disclosure generally relates to systems and techniques for polymerization and, more particularly, to systems and techniques for withdrawing polymer products from a reactor. For example, polyolefins can be prepared as polyolefin flakes or particles carried in a reaction fluid. The systems and techniques according to the present disclosure can be used, for example, to withdraw polymer products, such as discrete, specific, sheet-like, or other polymer products, from a polymerization reactor during continuous operation and polymer production in the polymerization reactor.

[0045] Figure 1 is a conceptual block diagram showing a polymerization system 1 that includes a downflow polymer product withdrawal system 10 coupled to a polymerization reactor 12. System 10 includes a withdrawal line 14 coupled to a reactor outlet 16 of the reactor and located downstream of the reactor outlet. The withdrawal line 14 can be coupled directly to the outlet 16 or through an intermediate element. For example, system 10 can also include a sparger configured to couple the top of the withdrawal line 14 to an above-bed outlet or a lower-pressure outlet of the reactor.

[0046] The reactor outlet 16 is configured to collect and discharge a product comprising a powder and a carrier gas. The powder comprises a polymer. The polymerization reactor 12 can be any suitable polymerization reactor, and the polymer product can comprise any polymer, such as in the form of a powder, flake, or pellet. In various aspects, the polymerization reactor can be a polyolefin reactor, and the polymer product can comprise a polyolefin. In some such aspects, the polyolefin can comprise polyethylene or polypropylene. The polymerization reactor 12 can comprise a single reactor or can comprise a plurality of reactors connected in series and / or parallel. In various aspects, the polymerization reactor 12 comprises a gas-phase polyolefin reactor or a loop slurry polyolefin reactor.

[0047] The draw line 14 defines a downstream volume. The draw line 14 comprises at least one downwardly inclined descending section, as Figure 1 shown. The draw line 14 does not have any non-self-draining regions. For example, after the flow comprising the polymer product has passed through, there can be no regions in the draw line 14 where the polymer product is collected or retained.

[0048] The size of the downstream volume of the draw line 14 can be set to collect and retain sufficient product to facilitate subsequent densification in the lock hopper 18. In various aspects, the downstream volume is greater than 80% of the volume of the lock hopper 18 (e.g., chamber 20). In some such aspects, the downstream volume is greater than 90% of the volume of the lock hopper 18. In some such aspects, the downstream volume is 100% or less of the volume of the lock hopper 18. In some such aspects, the downstream volume is substantially 100% of the volume of the lock hopper 18. Without being bound by theory, providing a downstream volume that is substantially the same as or slightly less than the volume of the lock hopper 18 can avoid product agglomeration remaining in the draw line 14 between a series of draws or during multiple draws.

[0049] The draw line 14 can have any suitable cross-section, such as a circular or oval cross-section, or any curved or linear portion or combination thereof. Thus, in various aspects, the downwardly inclined descending section of the draw line 14 can be substantially cylindrical. In various aspects, the draw line 14 consists of at least the downwardly inclined descending section. In various aspects, the draw line 14 can comprise one, two, or more downwardly inclined descending sections. In various aspects, the draw line 14 comprises only a single downwardly inclined descending section.

[0050] In various aspects, the extraction line 14 has no vertical sections. In various aspects, the extraction line has no substantially vertical sections. Avoiding vertical portions can reduce or prevent fluidization of the powder in the extraction line 14 (which can slow powder flow), and substantially allows residual gas to flow upward past the downward flowing powder back to the reactor 12. For example, each portion of the extraction line 14 can be inclined away from the vertical direction associated with gravity by at least 5 degrees, or at least 10 degrees, or at least 15 degrees, or at least 20 degrees, or at least 25 degrees, or at least 30 degrees.

[0051] In various aspects, the extraction line 14 has no bends. For example, the extraction line 14 can extend along a substantially straight line. Without being bound by theory, avoiding bends can reduce or prevent product accumulation or agglomeration in the extraction line 14.

[0052] In various aspects, at least one downwardly inclined decline section defines a slope greater than or equal to 10 degrees relative to the vertical axis. In various aspects, the slope is less than or equal to 30 degrees. In some aspects, the slope is greater than the angle of repose of the polymer product. In some aspects, the slope is greater than the critical chute angle. Without being bound by theory, providing a slope greater than one or both of the angle of repose or the critical chute angle can reduce or prevent product accumulation or agglomeration in the extraction line 14. For example, the slope can allow the carrier gas in the extraction line to flow upward in the extraction line and above the polymer product or powder flowing downward from the reactor.

[0053] The system 10 further includes a lock hopper 18 that is coupled to the extraction line 14 and is located downstream of the extraction line. The lock hopper 18 defines a chamber 20 that is configured to receive at least a portion of the powder and carrier gas from the extraction line 14. The lock hopper 18 can be formed of metal or an alloy and have any suitable shape and size. In various aspects, the lock hopper 18 can include a cylindrical top section joined to a conical bottom section. The center of the conical bottom section can be aligned with or offset from the center of the cylindrical top section. The same axis can extend through the centers of both the cylindrical top section and the conical bottom section. Thus, the chamber 20 can be defined by the cylindrical top section and the conical bottom section. The cylindrical top shape can facilitate the collection and retention of a relatively high density of the collected product, and the conical bottom shape can facilitate subsequent discharge of the product from the lock hopper 18. In some embodiments, the conical bottom section can be a partial conical section, such as a semi-conical section or an eccentric conical section.

[0054] System 10 further includes a fill valve 22 located between the draw line 14 and the lock hopper 18, and a discharge valve 24 located downstream of the lock hopper 18. The fill valve 22 and the discharge valve 24 can include any suitable valves for allowing or blocking the flow of a polymer product (such as powder, flakes or pellets) in a carrier stream (such as a gas).

[0055] In various aspects, the lock hopper axis extends along a vertical axis. In some aspects, one or both of the fill valve 22 and the discharge valve 24 extend along the vertical axis, as Figure 1 shown. Providing the lock hopper 18 with a vertical orientation can facilitate relatively rapid settling and promote densification of the polymer product collected in the lock hopper 18. Providing the fill valve 22 and the discharge valve 24 in a vertical orientation can facilitate rapid flow of the polymer product and reduce clogging or agglomeration.

[0056] In various aspects, the flow diameter of one or both of the fill valve 22 and the discharge valve 24 is greater than or equal to the flow diameter of the draw line 14. In some aspects, the flow diameter of one or both of the fill valve 22 and the discharge valve 24 is the same as the flow diameter of the draw line 14.

[0057] The polymer product collected in the lock hopper 18 can be discharged periodically. For example, system 10 can further include a discharge line 25 coupled to the discharge valve 24. In some aspects, there are no bends in the discharge line 25. Avoiding excessive bends in the discharge line 25 can reduce or prevent the formation of a skin associated with high temperatures caused by friction at the bends. Using a relatively short length for the discharge line 25 can also facilitate an increased draw rate.

[0058] System 10 can further include a reactor outlet valve 26 along the draw line 14 and adjacent to the reactor outlet 16. In some aspects, the reactor outlet valve 26 is a pinch valve that is configured to seal the flow at the reactor inner diameter to prevent clogging of the reactor nozzle when the draw line 14 is not in use but the reactor 12 is operating. The reactor outlet valve 26 can be opened to release material and pressurize the draw line 14 to the pressure of the reactor 12, and can be closed to isolate the draw line 14 from the reactor 12.

[0059] The polymerization system 1 can also include a separator 28 coupled to the downflow polymer product draw system 10. For example, the separator 28 can be a gas-particle separator to reduce or remove residual gas carried by the polymer product.

[0060] Reference Figures 2A to 2F and Figure 3 describes the operation of the downflow polymer product draw system 10 of the polymerization system 1.

[0061] Figures 2A to 2F is a conceptual diagram showing different stages of product withdrawal in a downflow polymer product withdrawal system (e.g., Figure 1 system 10). In Figures 2A to 2F , one or both of valves 22 and 24 are in the closed position 22a or 24a, or in the open position.

[0062] Figure 2A is a conceptual diagram illustrating the system in an initial configuration 10a. In the initial configuration 10a, there is a plunger P accumulating against the closed fill valve 22a in the withdrawal line 14. The plunger P can be formed by residual solids remaining in the withdrawal line 14 during a previous withdrawal cycle and due to the reactor contents settling into the withdrawal line 14. The plunger P can substantially have the sedimentation bulk density of solids (polymer product). The volume upstream of the plunger P in the withdrawal line can include a solid concentration C. Since the plunger P is relatively dense and immobile, the solid concentration C remains stable behind the plunger P in the initial configuration 10a. The lock hopper 18 is substantially free of polymer product, and the discharge valve 24a is also closed. Some residual gas from the previous withdrawal cycle can be retained in the lock hopper 18, thereby providing a slight positive pressure. In various aspects, the positive pressure can be about 10 psig.

[0063] Figure 2B is a conceptual diagram illustrating the system in an intermediate plunger release configuration 10b. The configuration 10b is achieved by closing the discharge valve 24a but opening the fill valve 22 to allow the plunger P to be released from the withdrawal line and flow into the lock hopper 18. Thus, the contents of the plunger P are now transferred to the lock hopper 18 and substantially accumulate at the bottom of the lock hopper 18. For example, the contents of the plunger P can now occupy the conical bottom portion of the lock hopper 18. In some aspects, the plunger P occupies a major portion of the volume of the lock hopper 18.

[0064] When the plunger P moves into the lock hopper 18, gas and solids can move from the reactor outlet 16 into the withdrawal line 14. This can occur at a solid concentration that is a portion (e.g., 60 to 100%, or another proportion that can depend on the solid permeability) of the solid concentration in the reactor 12. This volume will expand in the line to push the remaining original contents of the line into the barrel (the plunger P plus the volume C behind the plunger). This volume that expands into the line volume represents the initial solid concentration ("concentration 1") in the line when the lock hopper 18 starts to be pressurized.

[0065] The gas from the plunger P and the gas initially associated with the solid content C behind the plunger P can now expand along the withdrawal line 14 and enter the lock hopper 18 to pressurize the lock hopper 18.

[0066] Figure 2C is a conceptual diagram illustrating a system in an intermediate pressure configuration 10c. The fill valve 22 remains open, with the discharge valve 24a closed. The lock hopper 18 is pressurized to the full reactor pressure, bringing a mixture that is a portion of the reactor fluidized bed density. For example, this portion can be the average of concentration 1 and 40% to 90% of the reactor solids concentration, or another portion depending on the solids permeability.

[0067] Figure 2D is a conceptual diagram illustrating a system in an intermediate solids settling configuration 10d. The fill valve 22 remains open, with the discharge valve 24a closed. After the lock hopper 18 is fully pressurized, solids continue to settle into the barrel during the remaining time the fill valve 22 remains open. The accumulated solids in the lock hopper 18 are a combination of solids from the plunger P, solids from the volume C behind the plunger, solids from the final pressurization, and solids that settle after pressurization. Eventually, most of the lock hopper 18 can be occupied by solids. For example, greater than 50%, or greater than 60%, or greater than 70%, or greater than 80%, or greater than 90%, or greater than 95% of the volume of the lock hopper 18 can be occupied by the bulk density of the solids.

[0068] The settling rate can be related to a value approaching the minimum fluidization velocity in the vertical section of the pipe. However, providing a slope in the draw line 14 can allow solids to slide along the bottom of the draw line 14 as the gas passes over the top, thereby increasing the settling rate compared to the settling rate in the vertical section. This can play an important role in the sizing of the plunger in the draw line 14, especially at low draw frequencies when the settling time is maximized. If the settling rate is high or the initial plunger size is large, the effect of the draw velocity may be reduced.

[0069] Optionally using a jet or "ejector" pipe that connects the top of the draw line 14 to a location above the reaction bed in the reactor 12 can increase the settling rate from the reactor 12.

[0070] If the plunger size can be made close to or exceed the amount of solids that the lock hopper 18 can accommodate, the efficiency of the draw (pounds of solids per draw) can be increased. The initial plunger size may be affected by the volume of the draw line 14 relative to the lock hopper. The above situation can be achieved when the volume of the draw line 14 is close to or slightly exceeds the volume of the lock hopper 18. However, if the volume of the draw line 14 greatly exceeds the volume of the lock hopper 18, material may remain in the draw line 14 between individual draws of multiple draws, and may cause agglomeration in the draw line 14.

[0071] Figure 2EIt is a conceptual diagram showing the system in the intermediate solid release configuration 10e. The fill valve 22a is now closed, and the discharge valve 24 is open. The accumulated solids are discharged from the lock hopper 18. The accumulated lock hopper can substantially empty the solids into the discharge line 25, or into the separator 28, or otherwise used for further processing, storage, packaging, or transportation. Since the fill valve 22a is closed, the solids already in the draw line 14 settle in the line to start forming a plunger for the next cycle. Additional solids settle from the reactor 12 into the draw line 14.

[0072] Figure 2F It is a conceptual diagram illustrating the system in the final emptying configuration 10f. Now, the discharge valve 24a is closed, and the fill valve 22a remains closed. The lock hopper 18 is substantially free of solids. There may be some residual gas pressure in the lock hopper 18, for example, 10 psig. Figure 2F The configuration 10f now forms the initial configuration for the next draw cycle, and the draw cycle can continue.

[0073] Figure 3 It is a flowchart showing a technique for withdrawing a polymer product using a downflow polymer product withdrawal system coupled to a polymerization reactor. Although the various states of the downflow polymer product withdrawal systems 10a to 10f described with reference to Figure 1 the polymerization system 1 and with reference to Figures 2A to 2F describe Figure 3 the technique, the technique can be practiced using any suitable system according to the present disclosure.

[0074] At step 30, the technique includes opening the fill valve 22 of the downflow polymer product withdrawal system 10 to fluidly couple the lock hopper 18 to the reactor 12 through the draw line 14 (e.g., starting from the configuration 10a described with reference to Figure 2A open the fill valve 22).

[0075] At step 32, the technique further includes, after (30) opening the fill valve 22, receiving the plunger P containing powder and gas from the draw line 14 into the lock hopper 18 (e.g., referring to the configuration 10b described with reference to Figure 2B ).

[0076] At step 34, the technique further includes, after (32) receiving the plunger P, allowing the lock hopper 18 to be pressurized to the reactor pressure with the gas received from the reactor 12 through the draw line 14 (e.g., referring to the configuration 10c described with reference to Figure 2C ).

[0077] At step 36, the technique further includes, after pressurization at (34), allowing the powder from the withdrawal line 14 to continue to settle into the lock hopper 18 for a predetermined settling time (e.g., referring to Figure 2D the configuration 10d described).

[0078] At step 38, the technique further includes, after settling at (36), closing the fill valve 22 to isolate the lock hopper 18 from the withdrawal line 14 and the reactor 12 (e.g., referring to Figure 2E the configuration 10e described). In various aspects, after settling at (36), the solid concentration in the lock hopper 18 is greater than the solid concentration in the reactor 12.

[0079] At step 40, the technique further includes, after closing the fill valve 22b, opening the discharge valve 24 to discharge the contents of the lock hopper 18 (e.g., referring to Figure 2E the configuration 10e described).

[0080] At step 42, the technique further includes allowing a plug P to form in the withdrawal line 14 adjacent to the closed fill valve 22b by receiving a portion of the powder and gas from the reactor 12. In various aspects, the solid concentration of the plug P is 60 wt% to 150 wt% of the solid concentration in the reactor 12.

[0081] The technique may further include repeating any one of steps 30 to 42 one or more times.

[0082] In various aspects, when the reactor fluid bulk density is 15 lbs / ft 3 , the withdrawal bulk density of the material discharged from the downflow polymer product withdrawal system 10 is greater than 16 lbs / ft 3 withdrawal bulk density.

[0083] Thus, the downflow polymer product withdrawal system 10 can be used to advantageously withdraw the polymer product from the reactor 12 through repeated withdrawal cycles.

[0084] Reference Figures 4 to 16 describes additional withdrawal systems and techniques. Where the numbers of the components are the same as those of the components described in the reference Figures 1 to 3 , their structures and functions are substantially the same as those described in the reference Figures 1 to 3 described.

[0085] Figure 4 is a conceptual block diagram showing a polymerization system 2, which includes an upflow polymer product withdrawal system 50 coupled to a polymerization reactor 12. The system 50 is coupled to the reactor outlet 16 of the reactor 12. The location of the reactor outlet 16 may be the same as or different from the location in the Figure 1 system 1.

[0086] The system 50 includes a draw line 54 coupled to the reactor outlet 16 and located downstream of the reactor outlet, which is configured to collect and discharge a product comprising powder and carrier gas. The system 50 may also include an injection pipe configured to couple the top of the draw line 54 to a lower pressure region of the reactor 12.

[0087] The draw line 54 defines an upstream volume. The draw line 54 includes at least one non-vertical section. For example, the non-vertical section includes at least one upwardly inclined riser section 56 and at least one downwardly inclined downcomer section 58. In some aspects, the upstream volume is defined only by the downwardly inclined downcomer section 58. The upwardly inclined riser section 56 is located downstream of the reactor 12, and the downwardly inclined downcomer section 58 is located downstream of the upwardly inclined riser section. There is no non-self-draining region in the draw line 54.

[0088] The system 50 includes a lock hopper 18 coupled to at least one downwardly inclined downcomer section 58 of the draw line 54 and located downstream of the at least one downwardly inclined downcomer section. The lock hopper defines a chamber 20 configured to receive at least a portion of the powder and carrier gas from the draw line 54.

[0089] The upstream volume and the volume of the lock hopper 18 may be set such that the sum of the upstream volume (e.g., the volume of the downwardly inclined downcomer section 58) and the lock hopper volume is sufficient to accommodate enough solids at a "transfer" solids concentration to completely fill the lock hopper volume with solids at a "settled" (e.g., bulk density) solids concentration.

[0090] The system 50 includes a fill valve 22 between the draw line 54 and the lock hopper 18. In various aspects, the fill valve 22 is positioned along the downwardly inclined downcomer section 58 or at the end of the downwardly inclined downcomer section 58. The system 50 includes a discharge valve 24 located downstream of the lock hopper 18.

[0091] The system 50 may include a reactor isolation valve 52 along at least one upwardly inclined riser section 56. In various aspects, the reactor isolation valve 52 is located at or adjacent to the end of the at least one upwardly inclined riser section 56. In various aspects, the reactor isolation valve 52 is coupled to the reactor outlet 16. The reactor isolation valve 52 may be a pinch valve.

[0092] In various aspects, the upstream volume is less than or equal to 50% of the volume of the lock hopper 18. In various aspects, the upstream volume is greater than 25% of the volume of the lock hopper 18. In various aspects, the upstream volume is in the range of 25% to 50% of the volume of the lock hopper 18.

[0093] To reduce or prevent agglomeration or plugging and to allow or promote gas flow upward along the withdrawal line 54 above the settling solids toward the reactor 12, the withdrawal line 54 may have no vertical sections. The withdrawal line 54 may have no substantially vertical sections.

[0094] In various aspects, at least one upwardly inclined riser section 56 defines a riser slope of greater than or equal to 10 degrees relative to the vertical axis. In various aspects, at least one downwardly inclined downcomer section 58 defines a downcomer slope of greater than or equal to 10 degrees relative to the vertical axis. In some aspects, one or both of the riser slope and the downcomer slope are less than or equal to 30 degrees. In some aspects, one or both of the riser slope and the downcomer slope are greater than one or both of the critical chute angle or the angle of repose of the polymer product. In some aspects, the riser slope is substantially equal to the downcomer slope. In various aspects, the downcomer slope allows the carrier gas in the withdrawal line 54 to flow upward in the withdrawal line 54 and above the powder flowing downward from the reactor 12.

[0095] In various aspects, the withdrawal line 54 has a cross-section similar to that described for the withdrawal line 14 of the reference system 1. In some aspects, the inclined section of the withdrawal line 54 is cylindrical. In some aspects, the withdrawal line consists of inclined sections. In various aspects, the inclined sections have no bends.

[0096] One or both of the lock hopper 18 and the discharge valve 24 may extend along the vertical axis, while the fill valve 22 may be inclined relative to the vertical axis, as Figure 4 shown. In various aspects, the flow diameter of one or both of the fill valve 22 and the discharge valve 24 is greater than or equal to the flow diameter of the withdrawal line 54. In various aspects, the flow diameter of one or both of the fill valve 22 and the discharge valve 24 is the same as the flow diameter of the withdrawal line 54. This configuration can reduce or prevent blockage or flow reduction in these components.

[0097] For example, the system 50 may further include a discharge line 25 coupled to the discharge valve 24. The polymerization system 2 may further include a separator 28 coupled to the upflow polymer product withdrawal system 50.

[0098] Reference Figures 5A to 5D and Figure 6 describe the operation of the upflow polymer product withdrawal system 10 of the polymerization system 1.

[0099] Figures 5A to 5D is a conceptual diagram showing different stages of product withdrawal in the upflow polymer product withdrawal system 50. In Figures 5A to 5D one, one or both of the valves 22 and 24 are in the closed positions 22a or 24a, or in the open position.

[0100] Figure 5A is a conceptual diagram illustrating the system in the initial configuration 50a. In the initial configuration 50a, the lock hopper 18 is substantially free of polymer product, and the residual gas from the previous draw cycle leaves a slight positive pressure in the lock hopper 18. For example, the residual pressure can be about 10 psig. Both the fill valve 22a and the discharge valve 22a are closed. The system is now ready to start a new draw cycle.

[0101] Figure 5B is a conceptual diagram illustrating the system in the intermediate pressurization configuration 50b. In the intermediate configuration 50b, the fill valve 22 is opened to allow gas and solids to enter and pressurize the lock hopper 18. The discharge valve 24a remains closed. The mixture is at or below the solid concentration in the reactor.

[0102] Figure 5C is a conceptual diagram illustrating the system in the intermediate settling configuration 50c. In the intermediate configuration 50c, the fill valve 22 remains open and the discharge valve 24a remains closed, which allows the lock hopper to reach the reactor pressure. The upflow volume and the solids in the lock hopper 18 settle in the lock hopper. After sufficient settling time, the fill valve 22a is closed to isolate the lock hopper 18 from the draw line 54 and the reactor 12, and the discharge valve 24 is opened to allow the settled solids to be discharged from the lock hopper 18, resulting in Figure 5D the final configuration.

[0103] Figure 5D is a conceptual diagram illustrating the system in the final evacuation configuration 50d. In the final empty configuration, there is substantially no solid in the lock hopper 18. Closing the discharge valve 24 cycles the system back to the initial configuration 50a, preparing it for the next draw cycle.

[0104] Figure 6 is a flow chart showing a technique for withdrawing a polymer product using an upflow polymer product withdrawal system coupled to a polymerization reactor. Although the various states of the upflow polymer product withdrawal systems 50a to 50d described with reference to Figure 4 the polymerization system 2 of Figures 5A to 5D and with reference to Figure 6 describe the technique, the technique can be practiced using any suitable system according to the present disclosure.

[0105] At step 60, the technique includes opening the fill valve 22 of the upflow polymer product withdrawal system 50 to fluidly couple the lock hopper 18 to the reactor 12 via the draw line 54 (e.g., starting from the configuration 50a described with reference to Figure 5A open the fill valve 22).

[0106] At step 62, the technique further includes receiving a mixture of powder and gas from the withdrawal line 54 into the lock hopper 18 after opening the fill valve 22 at (60), and allowing the lock hopper 18 to be pressurized to the reactor pressure (e.g., referring to Figure 5B the configuration 50b described).

[0107] At step 64, the technique further includes allowing powder from the withdrawal line to continue to settle into the lock hopper 18 for a predetermined settling time after pressurization at (62) (e.g., referring to Figure 5C the configuration 50c described). In various aspects, after settling at (64), the reactor isolation valve 52 closes before the fill valve 22 closes. After settling at (64), the lock hopper 18 may be substantially completely occupied by the settled solids.

[0108] At step 66, the technique further includes closing the fill valve 22 and the reactor isolation valve 52 after settling at (64) to isolate the lock hopper 18 from the withdrawal line 54 and the reactor 12 (e.g., after the configuration 50c described in the reference Figure 5C ).

[0109] At step 68, the technique further includes opening the discharge valve 24 to discharge the contents of the lock hopper 18 after closing the fill valve at (66) (only before the configuration 50d described in the reference Figure 5D ). In some aspects, the valve 24 may be closed before proceeding to the next cycle.

[0110] In various aspects, the solid concentration of the mixture in the lock hopper is equal to or greater than the solid concentration in the reactor.

[0111] In various aspects, the technique includes repeating steps 60 to 68 one or more times.

[0112] In various aspects, when the reactor fluid bulk density is 15 lbs / ft 3 , the withdrawal bulk density of the material discharged from the upflow polymer product withdrawal system is greater than or equal to 16 lbs / ft 3 withdrawal bulk density.

[0113] Accordingly, the upflow polymer product withdrawal system 50 can be used to advantageously withdraw polymer product from the reactor 12 through repeated withdrawal cycles.

[0114] Figure 7 is a conceptual block diagram showing a polymerization system 3, which includes a fluidized upflow polymer product withdrawal system 80 coupled to a polymerization reactor 12. The system 80 is coupled between a higher pressure or lower pressure reactor outlet 16 of the reactor 12 and a lower pressure or higher pressure reactor outlet 82. The location of the reactor outlet 16 can be the same asFigure 1 at the same or different positions in system 1.

[0115] System 80 includes an upper draw line 84 coupled to an upper reactor outlet 16, which is configured to collect and discharge a product containing powder and carrier gas. System 3 may also include a sparge pipe configured to couple the top of the upper draw line 84 to an outlet above the bed or a lower pressure outlet of the reactor 12. The upper draw line 84 defines an upper upflow volume. The upper draw line 84 includes at least one descending non-vertical section. The upper draw line 84 has no non-self-draining regions. The upper draw line 84 may have no substantially vertical sections.

[0116] System 80 includes a lock hopper 18 coupled to the upper draw line 84 and located downstream of the upper draw line. The lock hopper 18 defines a chamber 20 configured to receive at least a portion of the powder and carrier gas from the upper draw line 84.

[0117] System 80 also includes a lower draw line 86 coupled to the lock hopper 18 and located downstream of the lock hopper. The lower draw line 86 is coupled to a lower reactor outlet 82, which is configured to collect and discharge a product. The lower draw line 86 includes at least one ascending section. The ascending section may be vertical or inclined at an ascending angle from 0 to 20 degrees from vertical.

[0118] The diameter of the lock hopper 18 is set such that when a flow path through the lock hopper 18 is established along the lower draw line 86 and the upper draw line 84, a minimum fluidization is maintained. In various aspects, the diameter of the lock hopper may be between d and 3 x d, or between d and 1.5 x d, where d is the draw line diameter (upper line or lower line). In some aspects, both the upper draw line 84 and the lower draw line 86 have substantially the same diameter.

[0119] System 80 includes at least one upper fill valve 22 located between the upper draw line and the lock hopper. System 80 includes a lower fill valve 88 located between the lock hopper and the lower draw line 86, and a discharge valve 24 for discharging the contents of the lock hopper. In various aspects, the flow diameter of the upper fill valve 22 is greater than or equal to the flow diameter of the upper draw line 84, and the flow diameter of the lower fill valve 88 is greater than or equal to the flow diameter of the lower draw line 86. In some aspects, the flow diameter of the upper fill valve 22 is the same as the flow diameter of the upper draw line 84, and the flow diameter of the lower fill valve 88 is the same as the flow diameter of the lower draw line 86. System 80 may also include a reactor outlet valve 26 located between the upper reactor outlet 12 and the upper draw line 84.

[0120] In various aspects, the upper reactor outlet 16 is positioned at 60% to 100% of the fluidized bed height of the reactor 12. In various aspects, the lower reactor outlet 82 is positioned at 0% to 30% of the fluidized bed height of the reactor 12.

[0121] The upper upflow volume can be less than or equal to 50% of the volume of the lock hopper. Without being bound by theory, not exceeding 50% of the volume of the lock hopper can allow the upper upflow volume to minimize the solid inventory remaining in the draw line 84 at the end of sedimentation. The upper upflow volume can be greater than 25% of the volume of the lock hopper 18. Such a volume can help account for the difference in the sedimented bulk density and the fluidized bulk density of the polymer product under reactor conditions.

[0122] To facilitate the return of gas above the downward flowing solid stream back to the reactor 12 and to reduce or prevent plugging or agglomeration, the upper draw line 84 can be free of any vertical sections.

[0123] In various aspects, the descending non-vertical portion defines a descending slope that is greater than or equal to 10 degrees relative to the vertical axis. In various aspects, the descending slope is less than or equal to 30 degrees. In various aspects, the descending slope is greater than one or both of the critical chute angle or the angle of repose of the polymer product.

[0124] One or both of the upper draw line 84 and the lower draw line 86 can have a cross-section as described for the draw line 14 of reference system 1. For example, one or both of the ascending section and the descending non-vertical section can be cylindrical.

[0125] In various aspects, one or both of the ascending section and the descending non-vertical section are free of any bends.

[0126] System 3 can also include a discharge line 25 coupled to the discharge valve 24 and can also include a separator 28.

[0127] In various aspects, the discharge valve 25 is a diverter valve D (as shown) that is coupled to the lock hopper 18 and is located downstream of the lock hopper. The diverter valve D can be coupled to the downstream discharge line 25. The diverter valve can have a draw position D1 that couples the lock hopper 18 to the lower draw line 86 and a discharge position D2 that couples the lock hopper 18 to the downstream draw line 25. Figures 8A to 8C as

[0128] Refer to Figures 8A to 8C and Figure 9 Describe the operation of the fluidized upflow polymer product draw system 80 of polymerization system 3.

[0129] Figures 8A to 8C It is a conceptual diagram showing different stages of product extraction in the fluidized upflow polymer product extraction system 80.

[0130] Figure 8A It is a conceptual diagram illustrating the system in the fluidized configuration 80a. In configuration 80a, the diverter valve is in configuration D1, and the chamber 20 of the lock hopper 18 is exposed to the upper extraction line 84 and the lower extraction line 86. The upper fill valve 22, the nozzle valve 26, and the lower fill valve 88 are each opened, allowing the fluidized flow to flow from the lower or higher pressure reactor outlet 82 to the upper reactor outlet 16. Solids and gas are introduced through the lock hopper 18 by fluidization.

[0131] Figure 8B It is a conceptual diagram illustrating the system in the intermediate settling configuration 80b. In configuration 80b, the diverter valve is in the same configuration D1, and the upper fill valve 22 and the nozzle valve 26 remain open. However, the lower fill valve 88b is closed. Such a configuration prevents fluidization through the lower extraction line 86, and the solids settle in the lock hopper 18 at a packing density close to settling, while the residual gas flows upward and returns to the reactor 12 through the upper extraction line 84.

[0132] Figure 8C It is a conceptual diagram illustrating the system in the discharge configuration 80c. The lower fill valve 88b remains closed, and the upper fill valve 22b is closed, thus isolating the lock hopper 18 from the reactor 12. The diverter valve moves to the diversion configuration D2, which connects the lock hopper 18 to the discharge line 25, allowing the settled solids to be discharged via the discharge line 25. After discharge, the system cycles back to Figure 8A the configuration.

[0133] Figure 9 It is a flow chart showing the technique for extracting a polymer product using a fluidized upflow polymer product extraction system connected to a polymerization reactor. Although the technique is described with reference to Figure 7 the polymerization system 3 and with reference to Figure 8A the various states of the upflow polymer product extraction systems 80a to 80d described in FIGS. 8D, Figure 9 the technique can be practiced using any suitable system according to the present disclosure.

[0134] At step 100, the technique includes opening the upper fill valve 22 and the lower fill valve 88 of the fluidized upflow polymer product extraction system 3 to fluidly connect the lock hopper 18 to the reactor 12 through both the upper extraction line 84 and the lower extraction line 86 (e.g., with reference to Figure 8AThe described configuration 80a). The pressure difference between the upper reactor outlet and the lower reactor outlet can be greater than 60% of the pressure drop of the fluidized bed pressure in the reactor.

[0135] At step 102, the technique further includes, after opening the upper fill valve 22 and the lower fill valve 88 in (100), receiving the fluidized mixture of powder and gas from the upper draw line 84 and the lower draw line 86 into the lock hopper 18, and allowing the lock hopper 18 to be pressurized to the reactor pressure. Thus, the solids can settle in the lock hopper 18 while the gas moves to the upper line and the reactor.

[0136] At step 104, the technique further includes, after pressurization in (102), closing the lower fill valve 88 to isolate the lock hopper 18 from the lower draw line 86, stopping the fluidization in the lock hopper 18, and allowing the polymer product to settle in the lock hopper 18 (e.g., refer to Figure 8B the described configuration 80b). In some aspects, after settlement in (104), the lock hopper 18 is substantially completely occupied by the settled solids. Steps 102 and 104 can be combined.

[0137] At step 106, the technique further includes, after settlement in (104), closing the upper fill valve 22 to isolate the upper lock hopper 18 from the upper draw line 84 and the reactor 12 (e.g., resulting in reference to Figure 8C the described configuration 80c).

[0138] At step 108, the technique further includes, after isolation in (106), discharging the contents of the lock hopper 18 (e.g., refer to Figure 8C the described configuration 80c). Discharging the contents of the lock hopper 18 in (108) can include moving the diverter valve from the draw position D1 to the discharge position D2 to discharge the contents of the lock hopper 18. The system can then return to Figure 8A the configuration.

[0139] In various aspects, the technique further optionally includes, at step 110, closing the reactor outlet valve 26 after settlement in (104).

[0140] In various aspects, the technique further includes repeating one or more of steps 100 to 110 one or more times.

[0141] When the reactor fluid bulk density is 15 lbs / ft 3 , the draw bulk density of the material discharged from the fluidized upflow polymer product draw system is greater than or equal to 16 lbs / ft 3 .

[0142] Accordingly, the fluidized upflow polymer product withdrawal system 80 can be used to advantageously withdraw polymer product from the reactor 12 through repeated withdrawal cycles.

[0143] Figure 10 is a conceptual block diagram showing a polymerization system 4 that includes a continuous output polymer product withdrawal system 120 coupled to a polymerization reactor 12. For example, the system 120 can be coupled to the reactor outlet 16.

[0144] The system 120 includes a withdrawal line 124 that is coupled to the reactor outlet 16 and is located downstream of the reactor outlet. The system 4 can include a sparge tube that is configured to couple the top of the withdrawal line 124 to an above-bed outlet or a lower pressure outlet 16 of the reactor 12. In some aspects, the reactor outlet 16 can be less than 85% of the fluidized bed height. The withdrawal line 124 can be similar to the withdrawal line 14 described with reference to system 1. The withdrawal line 124 includes at least one non-vertical section and does not have any non-self-draining regions. The non-vertical section is cylindrical. In some aspects, the withdrawal line 124 consists of non-vertical sections.

[0145] In various aspects, the withdrawal line 124 does not have any vertical sections. In some aspects, the withdrawal line does not have any substantially vertical sections. The withdrawal line 124 can be free of any bends.

[0146] In various aspects, at least one non-vertical section defines a slope that is greater than or equal to 10 degrees relative to the vertical axis. The slope can be less than or equal to 30 degrees. The slope can be greater than the angle of repose of the polymer product or greater than the critical chute angle, either or both. The slope can allow the carrier gas in the withdrawal line 124 to flow upward in the withdrawal line 124 and above the powder flowing downward from the reactor 16.

[0147] The system 120 further includes a continuous output valve 122 that is coupled to the withdrawal line 124 and is downstream of the withdrawal line. Figure 11 is an image showing a partial view of the continuous output valve 122 in the continuous output polymer product withdrawal system 120. To facilitate flow and reduce or prevent settling or agglomeration in the valve 122, the flow diameter of the continuous output valve 122 can be greater than or equal to the flow diameter of the withdrawal line 124. In some aspects, the flow diameter of the continuous output valve 122 is the same as the flow diameter of the withdrawal line 124.

[0148] The continuous output valve 122 can include a valve housing 124 that holds a rotating element 126 that is rotatable about an axis 128. In some aspects, the rotating element 126 is in the form of a V-shaped ball, as Figure 11 shown. The valve 122 is in Figure 11Open in the configuration shown, where flow passes through the opening 130. For example, the opening 130 can have a V-shaped peripheral portion defined by a V-shaped ball. If the rotating element 126 is rotated in the direction of the arrow, the valve 122 closes by rotating the opening 130 to face the closing surface. In some such aspects, the rotating element 126 defines a V-shaped notch 132. When starting from the closed position and rotating to the open position, the V-shaped notch 132 can establish an initial flow. The V-shaped notch 132 can be oriented to face the bottom of the withdrawal line 124, towards the portion where the sedimentation product flows.

[0149] The valve 122 can be adjacent to the withdrawal line 124 or at the end of the withdrawal line 124. The valve 122 can be inclined along the withdrawal line 124. The system 120 can also include a discharge line 25 and a separator 28 coupled to the valve 122. In various aspects, the withdrawal line 25 can be inclined, for example, at substantially the same slope as a section of the withdrawal line 124.

[0150] The system 120 can also include an eccentric expander 134, which is located upstream of the continuous output valve 122 and coupled to the withdrawal line 124 and configured to convey powder downward and allow gas to flow upward over the powder. The cross-section of the eccentric expander 134 varies to allow different volumes of gas to flow along the length of the eccentric expander 134. In various aspects, the maximum cross-sectional area of the eccentric expander 134 is 1 to 4 times the minimum cross-sectional area. A ratio greater than 4 may result in unmixed regions prone to forming condensates. The eccentric expander 134 can extend along the entire length of the withdrawal line 124 or can only partially extend along the length of the withdrawal line 124.

[0151] The system 120 can include a reactor outlet valve 26. For example, the reactor outlet valve 26 can be adjacent to the reactor outlet 16 or located at the reactor outlet 16.

[0152] Figure 12 is a conceptual diagram showing an intermediate stage of product withdrawal in the continuous output polymer product withdrawal system 120.

[0153] The polymer product containing powder and gas can enter the withdrawal line 124 from the reactor 12 (e.g., when the reactor outlet valve 26 is open), where the solids settle along the bottom of the withdrawal line 124 and the gas returns to the reactor 12 above the top of the powder. The eccentric expander 134 can allow the gas to disengage from the powder into the vapor space, where the gas can flow back towards the reactor 12. The continuous output valve 122 rotates to at least partially open to allow the polymer product to be withdrawn downward, for example, into the discharge line 25. The line 25 can be vertical, horizontal, or inclined, and can be powered using entrained gas that expands as the pressure decreases.

[0154] Figure 13 is a flow chart showing a technique for withdrawing a polymer product using a continuous output polymer product withdrawal system 120 coupled to a polymerization reactor 12. At step 140, the technique includes receiving a continuous stream of product comprising powder and gas from the reactor outlet 16 into the withdrawal line 124. The reactor outlet valve 26 (if present) remains open.

[0155] At step 142, the technique further includes allowing the powder to flow downward along the withdrawal line 124 toward the continuous output valve 122. In various aspects, the residence time in the withdrawal line 124 can be from 2 seconds to 15 seconds. The residence time is the ratio of the volume of the withdrawal line 124 to the volumetric flow rate of the stream received from the outlet 16.

[0156] At step 144, the technique further includes allowing the gas to flow upward along the withdrawal line 122 toward the reactor outlet 16 and above the powder.

[0157] At step 148, the technique further includes continuously discharging at least a portion of the powder received at the continuous output valve 122.

[0158] At a reactor fluid bulk density of 15 lbs / ft 3 , the withdrawal bulk density of the material discharged from the continuous polymer product withdrawal system is greater than 16 lbs / ft 3 .

[0159] Thus, the fluidized upflow polymer product withdrawal system 120 can be used to advantageously withdraw polymer product from the reactor 12 through repeated withdrawal cycles.

[0160] Figure 14 is a conceptual block diagram showing a polymerization system 5 that includes a rotary cup polymer product withdrawal system 150 coupled to a polymerization reactor 12. For example, the system 150 can be coupled to the reactor outlet 16. The system 150 can further include a spray pipe configured to couple the top of the withdrawal line 154 to an above-bed outlet or a lower pressure outlet 16 of the reactor 12.

[0161] The system 150 includes a withdrawal line 154 coupled to the reactor outlet 16 and located downstream of the reactor outlet, which is configured to discharge a product comprising powder and carrier gas. The withdrawal line 154 can be similar to the withdrawal line 14 described with reference to system 1. The withdrawal line 154 includes at least one non-vertical section and does not have any non-self-draining regions.

[0162] The withdrawal line 154 can not have any vertical sections. The withdrawal line can not have any substantially vertical sections. The withdrawal line 154 can not have any bends.

[0163] At least one non-vertical section defines a slope greater than or equal to 10 degrees relative to the vertical axis. The slope can be less than or equal to 30 degrees. The slope can be greater than one or both of the angle of repose or the critical chute angle of the polymer product. The slope allows the carrier gas in the extraction line 154 to flow upward in the extraction line 154 and above the powder flowing downward from the reactor 12. The non-vertical section can be cylindrical. In some aspects, the extraction line 154 consists of a non-vertical section.

[0164] The system 150 further includes a rotary cup valve 152 coupled to the extraction line 154 and downstream of the extraction line. Figure 15A and Figure 15B is a conceptual diagram showing different stages of product extraction in the rotary cup polymer product extraction system 5. Figure 15A is a conceptual diagram showing the rotary cup valve in the receiving configuration 152a. Figure 15B is a conceptual diagram showing the rotary cup valve in the discharge configuration 152b. The rotary cup valve 152 includes a valve housing 155 that defines a receiving opening 156 and a discharge opening 158. Multiple cup valves can be used in association with a single extraction line 154.

[0165] The valve housing holds a rotatable cup element 160 having a cup opening 162 and a cup chamber 164. The cup element 160 can be formed of metal or alloy or any rigid material capable of chewing through solid polymer aggregates. In the receiving configuration 152a, the cup opening 162 at least partially overlaps or is substantially aligned with the receiving opening 156 to receive the polymer product from the extraction line 154 into the cup chamber 164. The cup element 160 is then rotated to the discharge configuration 152b, where the cup opening 162 at least partially overlaps or is substantially aligned with the discharge opening 158 to discharge the polymer product from the cup chamber 164 into, for example, a discharge line 25.

[0166] In various aspects, the flow diameter of the rotary cup valve 152 is greater than or equal to the flow diameter of the extraction line 154. In some aspects, the flow diameter of the rotary cup valve 152 is the same as the flow diameter of the extraction line 154.

[0167] Figure 16 is a flow chart showing the technique of extracting a polymer product using a rotary cup polymer product extraction system 150 connected to a polymerization reactor 12.

[0168] At step 170, the technique includes receiving a continuous flow of a product containing powder and gas from the reactor outlet 16 into the extraction line 154.

[0169] At step 172, the technique includes allowing the powder to flow downward along the extraction line toward the rotary cup valve 152.

[0170] At step 174, the technique includes allowing gas to flow upward along the extraction line 154 toward the reactor outlet 16 and above the powder.

[0171] At step 176, the technique includes continuously discharging a portion of the powder received at the continuously rotating cup valve 152. The continuous discharge may include sequentially rotating the cup valve element 160 between the receiving configuration 152a described with reference to Figure 15A and the discharge configuration 152b described with reference to Figure 15B .

[0172] Accordingly, the fluidized upflow polymer product extraction system 150 can be used to advantageously extract the polymer product from the reactor 12 through repeated extraction cycles.

[0173] The present invention has been described above with reference to multiple aspects, embodiments, and specific examples. From the above detailed description, those skilled in the art will envision many variations. All such obvious variations are within the full scope of the appended claims. Other aspects of the present invention may include, but are not limited to, the following aspects. Many aspects are described as "comprising" certain components or steps, but alternatively, unless otherwise specifically stated, may "consist essentially of those components or steps" or "consist of those components or steps".

[0174] Aspect

[0175] 1. A downflow polymer product extraction system, comprising:

[0176] An extraction line coupled to and downstream of a reactor outlet configured to collect and discharge a product comprising powder and carrier gas, the extraction line defining a downflow volume, the extraction line including at least one downwardly inclined descending section, and the extraction line having no non-self-discharging regions;

[0177] A lock hopper coupled to the extraction line and downstream of the extraction line, the lock hopper defining a chamber configured to receive at least a portion of the powder and the carrier gas from the extraction line;

[0178] A fill valve located between the extraction line and the lock hopper; and

[0179] A discharge valve located downstream of the lock hopper.

[0180] 2. The system of aspect 1, wherein the downflow volume is greater than 80% of the volume of the lock hopper.

[0181] 3. The system according to aspect 1, wherein the downstream volume is greater than 90% of the volume of the lock hopper.

[0182] 4. The system according to aspect 3, wherein the downstream volume is 100% or less of the volume of the lock hopper.

[0183] 5. The system according to aspect 4, wherein the downstream volume is substantially 100% of the volume of the lock hopper.

[0184] 6. The system according to any one of aspects 1 to 5, wherein the extraction line has no vertical sections.

[0185] 7. The system according to any one of aspects 1 to 6, wherein the at least one downwardly inclined descending section defines a slope greater than or equal to 10 degrees relative to the vertical axis.

[0186] 8. The system according to aspect 7, wherein the slope is less than or equal to 30 degrees.

[0187] 9. The system according to aspect 7, wherein the slope is greater than the angle of repose of the polymer product.

[0188] 10. The system according to aspect 7, wherein the slope is greater than the critical chute angle.

[0189] 11. The system according to any one of aspects 7 to 10, wherein the slope allows the carrier gas in the extraction line to flow upward in the extraction line and above the powder flowing downward from the reactor.

[0190] 12. The system according to any one of aspects 1 to 11, wherein the downwardly inclined descending section is cylindrical.

[0191] 13. The system according to any one of aspects 1 to 12, wherein the extraction line consists of the downwardly inclined descending section.

[0192] 14. The system according to any one of aspects 1 to 13, wherein the extraction line has no bends.

[0193] 15. The system according to any one of aspects 1 to 14, wherein the extraction line has no substantially vertical sections.

[0194] 16. The system according to any one of aspects 1 to 15, wherein the lock hopper includes a cylindrical top section joined to a conical bottom section and defines an axis extending through both the cylindrical top section and the conical bottom section.

[0195] 17. The system as described in aspect 16, wherein the axis of the lock hopper extends along a vertical axis.

[0196] 18. The system as described in any one of aspects 1 to 17, wherein one or both of the fill valve and the discharge valve extend along a vertical axis.

[0197] 19. The system as described in any one of aspects 1 to 18, wherein the flow diameter of one or both of the fill valve and the discharge valve is greater than or equal to the flow diameter of the draw line.

[0198] 20. The system as described in any one of aspects 1 to 19, further comprising a discharge line connected to the discharge valve, wherein the discharge line has no bends.

[0199] 21. The system as described in any one of aspects 1 to 20, further comprising a sparge pipe configured to connect the top of the draw line to an outlet above the bed or a lower pressure outlet of the reactor.

[0200] 22. A polymerization system, comprising:

[0201] A polymerization reactor having a reactor outlet configured to discharge a product comprising powder and carrier gas, wherein the powder comprises a polymer; and

[0202] A downflow polymer product draw system as described in any one of aspects 1 to 21, connected to the reactor outlet.

[0203] 23. A method of operating a polymerization system as described in aspect 22, the method comprising:

[0204] Opening the fill valve of the downflow polymer product draw system to fluidly connect the lock hopper to the reactor through the draw line;

[0205] After opening the fill valve, receiving a slug comprising powder and gas from the draw line into the lock hopper;

[0206] After receiving the slug, allowing the lock hopper to be pressurized to the reactor pressure with gas received from the reactor through the draw line;

[0207] After the pressurization, allowing powder from the draw line to continue to settle into the lock hopper for a predetermined settling time;

[0208] After the settling, closing the fill valve to isolate the lock hopper from the draw line and the reactor; and

[0209] After closing the fill valve, open the discharge valve to discharge the contents of the lock hopper.

[0210] 24. The method according to aspect 23, further comprising allowing a plunger to form in the draw line adjacent the closed fill valve by receiving a portion of powder and gas from the reactor.

[0211] 25. The method according to aspect 24, wherein the solids concentration of the plunger is 60 wt% to 150 wt% of the solids concentration in the reactor.

[0212] 26. The method according to any one of aspects 23 to 25, wherein after the settling, the solids concentration in the lock hopper is greater than the solids concentration in the reactor.

[0213] 27. The method according to aspect 25, further comprising repeating the steps of aspect 23 one or more times.

[0214] 28. The method according to aspect 27, wherein when the reactor fluid bulk density is 15 lbs / ft 3 the draw bulk density of the material discharged from the downflow polymer product draw system is greater than 16 lbs / ft 3 .

[0215] 29. An upflow polymer product draw system, comprising:

[0216] A draw line connected to the reactor outlet and located downstream of the reactor outlet, the reactor outlet being configured to collect and discharge a product comprising powder and carrier gas, the draw line defining an upflow volume, the draw line including at least one non-vertical section, the non-vertical section including at least one upwardly inclined riser section and at least one downwardly inclined downcomer section, the upwardly inclined riser section being located downstream of the reactor, the downwardly inclined downcomer section being located downstream of the upwardly inclined riser section, and there being no non-self-draining regions in the draw line;

[0217] A lock hopper connected to the at least one downwardly inclined downcomer section of the draw line and located downstream of the at least one downwardly inclined downcomer section of the draw line, the lock hopper defining a chamber configured to receive at least a portion of the powder and the carrier gas from the draw line;

[0218] A fill valve located between the draw line and the lock hopper; and

[0219] A discharge valve located downstream of the lock hopper.

[0220] 30. The system as described in aspect 29, wherein the upstream volume is located only within the at least one downwardly inclined descending section.

[0221] 31. The system as described in aspect 29 or 30, wherein the upstream volume is less than or equal to 50% of the volume of the closed hopper.

[0222] 32. The system as described in any one of aspects 29 to 31, wherein the upstream volume is greater than 25% of the volume of the closed hopper.

[0223] 32. The system as described in aspects 29 to 30, wherein the upstream volume is in the range of 25% to 50% of the volume of the closed hopper.

[0224] 34. The system as described in any one of aspects 29 to 33, wherein the extraction line has no vertical sections.

[0225] 35. The system as described in any one of aspects 29 to 34, wherein the at least one upwardly inclined ascending section defines an ascending slope greater than or equal to 10 degrees relative to the vertical axis.

[0226] 36. The system as described in any one of aspects 29 to 35, wherein the at least one downwardly inclined descending section defines a descending slope greater than or equal to 10 degrees relative to the vertical axis.

[0227] 37. The system as described in aspect 36, wherein one or both of the ascending slope and the descending slope are less than or equal to 30 degrees.

[0228] 38. The system as described in aspect 36 or 37, wherein one or both of the ascending slope and the descending slope are greater than the critical chute angle.

[0229] 39. The system as described in any one of aspects 36 to 38, wherein one or both of the ascending slope and the descending slope are greater than the angle of repose of the polymer product.

[0230] 40. The system as described in any one of aspects 36 to 39, wherein the ascending slope is substantially equal to the descending slope.

[0231] 41. The system as described in any one of aspects 36 to 40, wherein the descending slope allows the carrier gas in the extraction line to flow upward in the extraction line and above the powder flowing downward from the reactor.

[0232] 42. The system as described in any one of aspects 29 to 41, wherein the inclined section is cylindrical.

[0233] 43. The system according to any one of aspects 29 to 42, wherein the extraction pipeline consists of the inclined section.

[0234] 44. The system according to any one of aspects 29 to 43, wherein the inclined section has no bends.

[0235] 45. The system according to any one of aspects 29 to 44, wherein the extraction pipeline has no substantially vertical sections.

[0236] 46. The system according to any one of aspects 29 to 45, wherein the lock hopper includes a cylindrical top section joined to a conical bottom section and defines an axis extending through both the cylindrical top section and the conical bottom section.

[0237] 47. The system according to aspect 46, wherein the lock hopper axis extends along a vertical axis.

[0238] 48. The system according to any one of aspects 29 to 47, wherein the discharge valve extends along a vertical axis and wherein the fill valve is inclined relative to the vertical axis.

[0239] 49. The system according to any one of aspects 29 to 48, wherein the flow diameter of one or both of the fill valve and the discharge valve is greater than or equal to the flow diameter of the extraction pipeline.

[0240] 50. The system according to any one of aspects 29 to 49, further comprising a discharge pipeline coupled to the discharge valve, wherein the discharge pipeline has no bends.

[0241] 51. The system according to any one of aspects 29 to 50, further comprising a spray pipe configured to connect the top of the extraction pipeline to an outlet above the bed or a lower pressure outlet of the reactor.

[0242] 52. A polymerization system comprising:

[0243] A polymerization reactor having a reactor outlet configured to discharge a product containing powder and carrier gas, wherein the powder includes a polymer; and

[0244] An upflow polymer product extraction system according to any one of aspects 29 to 51, coupled to the reactor outlet.

[0245] 53. A method of operating a polymerization system according to aspect 52, the method comprising:

[0246] Opening the fill valve of the upflow polymer product extraction system to fluidly connect the lock hopper to the reactor through the extraction pipeline;

[0247] After opening the fill valve, a mixture of powder and gas is received from the withdrawal line into the lock hopper, and the lock hopper is allowed to be pressurized to the reactor pressure;

[0248] After the pressurization, powder from the withdrawal line is allowed to continue to settle into the lock hopper for a predetermined settling time;

[0249] After the settling, the fill valve and the equalizing valve are closed to isolate the lock hopper from the withdrawal line and the reactor; and

[0250] After closing the fill valve, the discharge valve is opened to discharge the contents of the lock hopper.

[0251] 54. The method according to aspect 53, wherein after the settling, the equalizing valve is closed before closing the fill valve.

[0252] 55. The method according to aspect 53 or 54, further comprising closing a second equalizing valve after the settling.

[0253] 56. The method according to any one of aspects 53 to 55, wherein the solids concentration of the mixture is equal to or greater than the solids concentration in the reactor.

[0254] 57. The method according to any one of aspects 53 to 56, the method further comprising repeating the steps as described in aspect 53 one or more times.

[0255] 58. The method according to aspect 57, wherein the withdrawn bulk density of the material discharged from the upflow polymer product withdrawal system is greater than or equal to 16 lbs / ft 3 .

[0256] 59. The method according to aspect 57, wherein when the reactor fluid bulk density is 15 lbs / ft 3 the withdrawn bulk density of the material discharged from the upflow polymer product withdrawal system is greater than or equal to 16 lbs / ft 3 .

[0257] 60. The method according to any one of aspects 53 to 59, wherein the lock hopper is substantially completely occupied by the settled solids after the settling.

[0258] 61. A fluidized upflow polymer product withdrawal system, comprising:

[0259] An upper extraction pipeline, which is connected to an upper reactor outlet configured to collect and discharge a product containing powder and carrier gas, the upper extraction pipeline defining an upper upward flow volume, the upper extraction pipeline including at least one descending non-vertical section, and there being no non-self-discharging area in the upper extraction pipeline;

[0260] A lock hopper, which is connected to the upper extraction pipeline and is located downstream of the upper extraction pipeline, the lock hopper defining a chamber configured to receive at least a portion of the powder and the carrier gas from the upper extraction pipeline;

[0261] A lower extraction pipeline, which is connected to the lock hopper and is located downstream of the lock hopper, the lower extraction pipeline being connected to a lower reactor outlet configured to collect and discharge the product, the lower extraction pipeline including at least one ascending section;

[0262] At least one upper filling valve, which is located between the upper extraction pipeline and the lock hopper;

[0263] A lower filling valve, which is located between the lock hopper and the lower extraction pipeline; and

[0264] A discharge valve for discharging the contents of the lock hopper.

[0265] 62. The system according to aspect 61, wherein the upper reactor outlet is positioned at 60% to 100% of the fluidized bed height of the reactor.

[0266] 63. The system according to aspect 61 or 62, wherein the lower reactor outlet is positioned at 0% to 30% of the fluidized bed height of the reactor.

[0267] 64. The system according to any one of aspects 61 to 63, further comprising a reactor outlet valve located between the reactor outlet and the upper extraction pipeline.

[0268] 65. The system according to any one of aspects 61 to 64, wherein the upper upward flow volume is less than or equal to 50% of the volume of the lock hopper.

[0269] 66. The system according to aspect 65, wherein the upper upward flow volume is greater than 25% of the volume of the lock hopper.

[0270] 67. The system according to any one of aspects 61 to 66, wherein the upper extraction pipeline does not have any vertical sections.

[0271] 68. The system according to any one of aspects 61 to 67, wherein the descending non-vertical section defines a descending slope greater than or equal to 10 degrees relative to the vertical axis.

[0272] 69. The system according to aspect 69, wherein the descending slope is less than or equal to 30 degrees.

[0273] 70. The system according to aspect 68 or 69, wherein the descending slope is greater than the critical chute angle.

[0274] 71. The system according to any one of aspects 68 to 70, wherein the descending slope is greater than the angle of repose of the polymer product.

[0275] 72. The system according to any one of aspects 61 to 71, wherein the ascending section is vertical or inclined at an ascending angle from 0 degrees to 20 degrees from the vertical.

[0276] 73. The system according to any one of aspects 61 to 72, wherein one or both of the ascending section and the descending non-vertical section are cylindrical.

[0277] 74. The system according to any one of aspects 61 to 73, wherein one or both of the ascending section and the descending non-vertical section do not have any bends.

[0278] 75. The system according to any one of aspects 61 to 74, wherein the upper withdrawal line does not have any substantially vertical sections.

[0279] 76. The system according to any one of aspects 61 to 75, wherein the lock hopper includes a cylindrical top section joined to a conical bottom section and defines an axis extending through both the cylindrical top section and the conical bottom section.

[0280] 77. The system according to aspect 76, wherein one or both of the lock hopper axis and the upper fill valve extend along the vertical axis.

[0281] 78. The system according to any one of aspects 61 to 77, wherein the flow diameter of the upper fill valve is greater than or equal to the flow diameter of the upper withdrawal line, and the flow diameter of the lower fill valve is greater than or equal to the flow diameter of the lower withdrawal line.

[0282] 79. The system according to any one of aspects 61 to 78, wherein the discharge line does not have any bends.

[0283] 80. The system according to any one of aspects 61 to 79, further comprising a spray pipe configured to connect the top of the withdrawal line to an outlet above the bed or a lower pressure outlet of the reactor.

[0284] 81. The system according to any one of aspects 61 to 80, wherein the discharge valve is a diverter valve connected to the lock hopper and located downstream of the lock hopper, the diverter valve is connected to a downstream discharge line, and the diverter valve has a draw position connecting the lock hopper to the lower draw line and a discharge position connecting the lock hopper to the downstream discharge line.

[0285] 82. A polymerization system comprising:

[0286] A polymerization reactor having an upper reactor outlet and a lower reactor outlet, the upper reactor outlet and the lower reactor outlet being configured to discharge a product comprising powder and carrier gas, wherein the powder comprises a polymer; and

[0287] The fluidized upflow polymer product draw system according to any one of aspects 61 to 81, which is connected between the upper reactor outlet and the lower reactor outlet.

[0288] 83. A method of operating the polymerization system according to aspect 82, the method comprising:

[0289] Opening the upper fill valve and the lower fill valve of the fluidized upflow polymer product draw system to fluidly connect the lock hopper to the reactor through both the upper draw line and the lower draw line;

[0290] After opening the upper fill valve and the lower fill valve, receiving a fluidized mixture of powder and gas into the lock hopper from the upper draw line and the lower draw line, and allowing the lock hopper to be pressurized to the reactor pressure;

[0291] After the pressurization, closing the lower fill valve to isolate the lock hopper from the lower draw line, stopping the fluidization in the lock hopper, and allowing the polymer product to settle in the lock hopper;

[0292] After the settling, closing the upper fill valve to isolate the lock hopper from the upper draw line and the reactor; and

[0293] After the isolation, discharging the contents of the lock hopper.

[0294] 84. The method according to aspect 83, wherein discharging the contents of the lock hopper comprises moving the diverter valve from the draw position to the discharge position to discharge the contents of the lock hopper.

[0295] 85. The method as described in aspect 83 or 84, further comprising closing the reactor outlet valve after said sedimentation.

[0296] 86. The method as described in aspect 83 or 84, further comprising repeating the steps of aspect 83 one or more times.

[0297] 87. The method as described in aspect 86, wherein when the reactor fluid bulk density is 15 lbs / ft 3 , the withdrawal bulk density of the material withdrawn from the fluidized upflow polymer product withdrawal system is greater than or equal to 16 lbs / ft 3 .

[0298] 88. The method as described in any one of aspects 83 to 87, wherein the pressure difference between the upper reactor outlet and the lower reactor outlet is greater than 60% of the fluidized bed pressure in the reactor.

[0299] 89. The method as described in any one of aspects 83 to 87, wherein the diameter of the lock hopper is 1.0 to 1.5 times the diameter of the upper withdrawal line.

[0300] 90. The method as described in any one of aspects 83 to 89, wherein the lock hopper is substantially completely occupied by the sedimented solids after said sedimentation.

[0301] 91. A continuous polymer product withdrawal system, comprising:

[0302] A withdrawal line, which is connected to the reactor outlet and is located downstream of the reactor outlet, the reactor outlet being configured to discharge a product containing powder and carrier gas, the withdrawal line including at least one non-vertical section, and there being no non-self-discharging areas in the withdrawal line; and

[0303] A continuous output valve, which is connected to the withdrawal line and is located downstream of the withdrawal line.

[0304] 92. The system as described in aspect 91, wherein there are no vertical sections in the withdrawal line.

[0305] 93. The system as described in aspect 91 or 92, wherein the at least one non-vertical section defines a slope greater than or equal to 10 degrees relative to the vertical axis.

[0306] 94. The system as described in aspect 93, wherein the slope is less than or equal to 30 degrees.

[0307] 95. The system as described in aspect 93, wherein the slope is greater than the angle of repose of the polymer product.

[0308] 96. The system as described in aspect 94, wherein the slope is greater than the critical chute angle.

[0309] 97. The system as described in any one of aspects 93 to 96, wherein the slope allows the carrier gas in the extraction line to flow upward in the extraction line and above the powder flowing downward from the reactor.

[0310] 98. The system as described in any one of aspects 91 to 97, wherein the non-vertical section is cylindrical.

[0311] 99. The system as described in any one of aspects 91 to 98, wherein the extraction line consists of the non-vertical section.

[0312] 100. The system as described in any one of aspects 91 to 99, wherein the extraction line has no bends.

[0313] 101. The system as described in any one of aspects 91 to 100, wherein the extraction line has no substantially vertical sections.

[0314] 102. The system as described in any one of aspects 91 to 101, wherein the flow diameter of the continuous output valve is greater than or equal to the flow diameter of the extraction line.

[0315] 103. The system as described in any one of aspects 91 to 102, further comprising an injection pipe configured to connect the top of the extraction line to an outlet above the bed of the reactor or a lower pressure outlet.

[0316] 104. The system as described in any one of aspects 91 to 103, wherein the reactor outlet is lower than 85% of the fluidized bed height.

[0317] 105. The system as described in any one of aspects 91 to 104, the system further comprising an eccentric expander located upstream of the continuous output valve and connected to the extraction line and configured to convey the powder downward and allow the gas to flow upward over the powder.

[0318] 106. The system as described in aspect 105, wherein the maximum cross-sectional area of the eccentric expander is 1 to 4 times the minimum cross-sectional area.

[0319] 107. A polymerization system, comprising:

[0320] A polymerization reactor having a reactor outlet configured to discharge a product comprising powder and carrier gas, wherein the powder comprises a polymer; and

[0321] A continuous polymer product withdrawal system as described in any one of aspects 91 to 106, which is connected to the reactor outlet.

[0322] 108. A method of operating a polymerization system as described in aspect 107, the method comprising:

[0323] Receiving a continuous product stream comprising powder and gas from the reactor outlet into a withdrawal line;

[0324] Allowing the powder to flow downward along the withdrawal line towards the continuous output valve;

[0325] Allowing the gas to flow upward along the withdrawal line towards the reactor outlet and above the powder;

[0326] Continuously discharging a portion of the powder received at the continuous output valve.

[0327] 109. The method as described in aspect 108, wherein the residence time in the withdrawal line is from 2 seconds to 15 seconds.

[0328] 110. The method as described in aspect 108 or 109, wherein when the reactor fluid bulk density is 15 lbs / ft 3 , the withdrawal bulk density of the material discharged from the continuous polymer product withdrawal system is greater than 16 lbs / ft 3 .

[0329] 111. A continuous polymer product withdrawal system, comprising:

[0330] A withdrawal line, which is connected to the reactor outlet and is located downstream of the reactor outlet, the reactor outlet being configured to discharge a product comprising powder and carrier gas, the withdrawal line comprising at least one non-vertical section, and there being no non-self-draining regions in the withdrawal line; and

[0331] A rotary cup valve, which is connected to the withdrawal line and is located downstream of the withdrawal line.

[0332] 112. The system as described in aspect 111, wherein there are no vertical sections in the withdrawal line.

[0333] 113. The system as described in aspect 111 or 112, wherein the at least one non-vertical section defines a slope of greater than or equal to 10 degrees relative to the vertical axis.

[0334] 114. The system as described in aspect 113, wherein the slope is less than or equal to 30 degrees.

[0335] 115. The system as described in aspect 113, wherein the slope is greater than the angle of repose of the polymer product.

[0336] 116. The system as described in aspect 114, wherein the slope is greater than the critical chute angle.

[0337] 117. The system as described in any one of aspects 113 to 116, wherein the slope allows the carrier gas in the extraction line to flow upward in the extraction line and above the powder flowing downward from the reactor.

[0338] 118. The system as described in any one of aspects 111 to 117, wherein the non-vertical section is cylindrical.

[0339] 119. The system as described in any one of aspects 111 to 118, wherein the extraction line consists of the non-vertical section.

[0340] 120. The system as described in any one of aspects 111 to 119, wherein the extraction line has no bends.

[0341] 121. The system as described in any one of aspects 111 to 120, wherein the extraction line has no substantially vertical sections.

[0342] 122. The system as described in any one of aspects 111 to 121, wherein the flow diameter of the rotary cup valve is greater than or equal to the flow diameter of the extraction line.

[0343] 123. The system as described in any one of aspects 111 to 122, further comprising an injection pipe configured to connect the top of the extraction line to an outlet above the bed or a lower pressure outlet of the reactor.

[0344] 124. A polymerization system comprising:

[0345] A polymerization reactor having a reactor outlet configured to discharge a product containing powder and carrier gas, wherein the powder includes a polymer; and

[0346] The continuous polymer product extraction system as described in any one of aspects 111 to 123, connected to the reactor outlet.

[0347] 125. A method of operating the polymerization system as described in aspect 124, the method comprising:

[0348] Receiving a continuous product stream containing powder and gas from the reactor outlet into the extraction line;

[0349] Allowing the powder to flow downward along the extraction line towards the rotary cup valve;

[0350] Allow the gas to flow upward along the extraction pipeline towards the reactor outlet and above the powder;

[0351] Continuously discharge a portion of the powder received at the continuously rotating cup valve.

Claims

1. A downflow polymer product withdrawal system, comprising: A withdrawal pipeline, which is connected to the reactor outlet and is located downstream of the reactor outlet. The reactor outlet is configured to collect and discharge a product containing powder and carrier gas. The withdrawal pipeline defines a downflow volume. The withdrawal pipeline includes at least one downwardly inclined descending section, and there is no non-self-discharging area in the withdrawal pipeline; A lock hopper, which is connected to the withdrawal pipeline and is located downstream of the withdrawal pipeline. The lock hopper defines a chamber, and the chamber is configured to receive at least a portion of the powder and the carrier gas from the withdrawal pipeline; A fill valve, which is located between the withdrawal pipeline and the lock hopper; And A discharge valve, which is located downstream of the lock hopper.

2. The system according to claim 1, wherein the downflow volume is greater than 80% of the volume of the lock hopper.

3. The system according to claim 1 or claim 2, wherein there is no vertical section in the withdrawal pipeline.

4. The system according to any one of claims 1 to 3, wherein the at least one downwardly inclined descending section defines a slope greater than or equal to 10 degrees with respect to the vertical axis.

5. The system according to claim 4, wherein the slope is greater than one or both of the angle of repose or the critical chute angle of the polymer product.

6. The system according to claim 4 or 5, wherein the slope allows the carrier gas in the withdrawal pipeline to flow upward in the withdrawal pipeline and above the powder flowing downward from the reactor.

7. The system according to claim 1, wherein the downwardly inclined descending section is cylindrical.

8. The system according to any one of claims 1 to 7, wherein the withdrawal pipeline consists of the downwardly inclined descending section.

9. The system according to any one of claims 1 to 8, wherein there is no bend in the withdrawal pipeline.

10. The system according to any one of claims 1 to 9, wherein the lock hopper includes a cylindrical top section joined to a conical bottom section, and defines an axis extending through both the cylindrical top section and the conical bottom section.

11. The system according to any one of claims 1 to 9, wherein one or more of the lock hopper axis, the fill valve, and the discharge valve extend along the vertical axis.

12. The system according to any one of claims 1 to 10, wherein the flow diameter of one or both of the fill valve and the discharge valve is greater than or equal to the flow diameter of the withdrawal pipeline.

13. The system according to any one of claims 1 to 12, further comprising a discharge pipeline connected to the discharge valve, wherein there is no bend in the discharge pipeline.

14. The system according to any one of claims 1 to 13, further comprising an injection pipe, which is configured to connect the top of the withdrawal pipeline to an outlet above the bed or a lower pressure outlet of the reactor.

15. A polymerization system, comprising: A polymerization reactor having a reactor outlet configured to discharge a product comprising powder and a carrier gas, wherein the powder comprises a polymer; and A downflow polymer product withdrawal system as claimed in any one of claims 1 to 14, coupled to the reactor outlet.

16. A method of operating a polymerization system, the polymerization system comprising a polymerization reactor and a downflow polymer product withdrawal system coupled to the reactor outlet of the polymerization reactor, the method comprising: Opening a fill valve of the downflow polymer product withdrawal system to fluidly couple a lock hopper to the polymerization reactor through a withdrawal line, the withdrawal line including at least one downwardly inclined section, and there being no non-self-draining regions in the withdrawal line; After opening the fill valve, receiving a slug comprising powder and gas from the withdrawal line into the lock hopper; After receiving the slug, allowing the lock hopper to be pressurized to reactor pressure with gas received from the reactor through the withdrawal line; After the pressurization, allowing powder from the withdrawal line to continue to settle into the lock hopper for a predetermined settling time; After the settling, closing the fill valve to isolate the lock hopper from the withdrawal line and the reactor; and After closing the fill valve, opening a discharge valve to discharge the contents of the lock hopper.

17. The method as claimed in claim 16, further comprising allowing the slug to form in the withdrawal line adjacent a closed fill valve by receiving a portion of the powder and gas from the reactor.

18. The method as claimed in claim 17, wherein the solid concentration of the slug is 60 wt% to 150 wt% of the solid concentration in the reactor.

19. The method as claimed in claim 16, further comprising repeating its steps one or more times.

20. The method according to claim 19, wherein when the reactor fluid bulk density is 15 lbs / ft 3 , the draw bulk density of the material discharged from the downflow polymer product withdrawal system is greater than 16 lbs / ft 3 .

21. An upflow polymer product withdrawal system, comprising: A withdrawal line coupled to a reactor outlet and located downstream of the reactor outlet, the reactor outlet being configured to collect and discharge a product comprising powder and a carrier gas, the withdrawal line defining an upflow volume, the withdrawal line including at least one non-vertical section, the non-vertical section including at least one upwardly inclined section and at least one downwardly inclined section, the upwardly inclined section being located downstream of the reactor, the downwardly inclined section being located downstream of the upwardly inclined section, and there being no non-self-draining regions in the withdrawal line; A lock hopper coupled to the at least one downwardly inclined section of the withdrawal line and located downstream of the at least one downwardly inclined section of the withdrawal line, the lock hopper defining a chamber configured to receive at least a portion of the powder and the carrier gas from the withdrawal line; A fill valve located between the withdrawal line and the lock hopper; and A discharge valve located downstream of the lock hopper.

22. A polymerization system, comprising: A polymerization reactor having a reactor outlet configured to discharge a product comprising powder and a carrier gas, wherein the powder comprises a polymer; and An upflow polymer product withdrawal system as claimed in claim 21, coupled to the reactor outlet.

23. A method of operating a polymerization system as claimed in claim 22, the method comprising: Opening a fill valve of the upflow polymer product withdrawal system to fluidly couple a lock hopper to the reactor via a withdrawal line; After opening the fill valve, receiving a mixture of powder and gas from the withdrawal line into the lock hopper and allowing the lock hopper to be pressurized to reactor pressure; After the pressurization, allowing powder from the withdrawal line to continue to settle into the lock hopper for a predetermined settling time; After the settling, closing the fill valve and an equalizing valve to isolate the lock hopper from the withdrawal line and the reactor; And After closing the fill valve, opening a discharge valve to discharge the contents of the lock hopper.

24. A fluidized upflow polymer product withdrawal system comprising: An upper withdrawal line coupled to an upper reactor outlet configured to collect and discharge a product comprising powder and a carrier gas, the upper withdrawal line defining an upper upflow volume, the upper withdrawal line including at least one descending non-vertical section and having no non-self-draining regions; A lock hopper coupled to the upper withdrawal line and located downstream of the upper withdrawal line, the lock hopper defining a chamber configured to receive at least a portion of the powder and the carrier gas from the upper withdrawal line; A lower withdrawal line coupled to the lock hopper and located downstream of the lock hopper, the lower withdrawal line coupled to a lower reactor outlet configured to collect and discharge the product, the lower withdrawal line including at least one ascending section; At least one upper fill valve located between the upper withdrawal line and the lock hopper; A lower fill valve located between the lock hopper and the lower withdrawal line; and A discharge valve for discharging the contents of the lock hopper.

25. A polymerization system comprising: A polymerization reactor having an upper reactor outlet and a lower reactor outlet, the upper reactor outlet and the lower reactor outlet being configured to discharge a product comprising powder and a carrier gas, wherein the powder comprises a polymer; and A fluidized upflow polymer product withdrawal system as claimed in claim 24, coupled between the upper reactor outlet and the lower reactor outlet.

26. A method of operating a polymerization system as claimed in claim 25, the method comprising: Opening the upper fill valve and the lower fill valve of the fluidized upflow polymer product withdrawal system to fluidly couple a lock hopper to the reactor via both the upper withdrawal line and the lower withdrawal line; After opening the upper fill valve and the lower fill valve, a fluidized mixture of powder and gas is received into the lock hopper from the upper draw line and the lower draw line, and the lock hopper is allowed to be pressurized to the reactor pressure; After the pressurization, the lower fill valve is closed to isolate the lock hopper from the lower draw line, fluidization in the lock hopper is stopped, and the polymer product is allowed to settle in the lock hopper; After the settling, the upper fill valve is closed to isolate the lock hopper from the upper draw line and the reactor; And After the isolation, the contents of the lock hopper are discharged.

27. A continuous polymer product withdrawal system, comprising: A draw line coupled to the reactor outlet and located downstream of the reactor outlet, the reactor outlet being configured to discharge a product comprising powder and carrier gas, the draw line including at least one non-vertical section, and the draw line having no non-self-draining regions; And A continuous output valve coupled to the draw line and located downstream of the draw line.

28. A polymerization system, comprising: A polymerization reactor having a reactor outlet configured to discharge a product comprising powder and carrier gas, wherein the powder comprises a polymer; and The continuous polymer product withdrawal system as claimed in claim 27, coupled to the reactor outlet.

29. A method of operating a polymerization system as claimed in claim 28, the method comprising: Receiving a continuous product stream comprising powder and gas from the reactor outlet into the draw line; Allowing the powder to flow downward along the draw line towards the continuous output valve; Allowing the gas to flow upward along the draw line towards the reactor outlet and above the powder; Continuously discharging a portion of the powder received at the continuous output valve.

30. A continuous polymer product withdrawal system, comprising: A draw line coupled to the reactor outlet and located downstream of the reactor outlet, the reactor outlet being configured to discharge a product comprising powder and carrier gas, the draw line including at least one non-vertical section, and the draw line having no non-self-draining regions; and A rotary cup valve coupled to the draw line and located downstream of the draw line.

31. A polymerization system, comprising: A polymerization reactor having a reactor outlet configured to discharge a product comprising powder and carrier gas, wherein the powder comprises a polymer; and The continuous polymer product withdrawal system as claimed in claim 30, coupled to the reactor outlet.

32. A method of operating a polymerization system as claimed in claim 33, the method comprising: Receiving a continuous product stream comprising powder and gas from the reactor outlet into the draw line; Allowing the powder to flow downward along the draw line towards the rotary cup valve; Allowing the gas to flow upward along the draw line towards the reactor outlet and above the powder; A portion of the powder received at the continuously rotating cup valve is continuously discharged.

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