A method for mixing a fluid melt flow stream with recirculation.

Abstract

This disclosure provides a process comprising an apparatus including (A) a passage for receiving a first flowstream (FFS1) having an inlet end and an outlet end on the opposite side; (B) a gear pump assembly downstream of the passage; (C) one or more conduits extending along the opposite side of the gear pump assembly, each conduit being in fluid communication with the outlet and passage of the gear pump assembly; and (D) injectors in each conduit for adding a second fluid (F2) into each conduit. The process comprises introducing F2 into the FFS1 from each outlet duct at a position upstream of the inlet of the gear pump assembly; supplying the FFS1 and F2 to the inlet of the gear pump assembly; mixing F2 with the FFS1 in the gear chamber to form a mixed fluid flowstream; and discharging it.

Description

[Technical Field]

[0001] Extruders and static mixers are commonly used to combine or otherwise mix two or more viscous materials, such as a polymer melt stream. Polymer melt streams are generally highly viscous, and in this process, they are typically layers without a natural mixing mechanism. The high viscosity of polymer melt streams makes the addition and mixing of small amounts of low-viscosity fluid products (additives) problematic. While extruders (either twin-screw or single-screw) can be used to mix lower-viscosity liquid additives into the polymer melt stream, extruders are difficult to scale up, and production costs increase rapidly when increased production capacity and extruder size are desired.

[0002] Using static mixers has the disadvantage of increasing capital costs. Static mixers obstruct the flow, and consequently, create a risk of significant pressure drops in the polymer melting flow production process. The pressure drop resulting from the addition of static mixers to the flow process can create potential dead zones in the production flow stream. Dead zones can lead to long-term degradation of the polymer melting stream process.

[0003] In this technical field, there is a recognized need for alternative mixing processes for polymer melt streams that avoid extruders and / or static mixers. [Overview of the project]

[0004] This disclosure provides a process. In embodiments, the process includes providing an apparatus. The apparatus includes (A) a passage having a side wall having an interior for receiving a first flowstream (FFS1), the passage having an inlet end and an outlet end opposite to it. The apparatus includes (B) a gear pump assembly, the gear pump assembly including (i) a housing, (ii) a gear chamber within the housing, (iii) an inlet for fluid communication between the outlet end of the passage and the gear chamber, (iv) a plurality of meshing gears mounted to rotate within the gear chamber, the gears having teeth that engage with each other within the chamber, and (v) an outlet for fluid communication with the gear chamber. The apparatus includes (C) one or more conduits, the conduits extending along the opposite side of the gear pump assembly. Each conduit has an outlet and is in fluid communication with the passage. Each conduit has an outlet duct for fluid communication with the passage. The apparatus includes (D) injectors in each conduit for adding a second fluid (F2) to each conduit. This process involves introducing a second fluid from each outlet duct to the upstream position of the inlet of FFS1, and supplying FFS1 and the second fluid to the inlet. This process involves mixing the second fluid with FFS1 in the gear chamber to form a mixed fluid flowstream (mFFS), and discharging the mFFS from the outlet. [Brief explanation of the drawing]

[0005] [Figure 1] This is a cross-sectional view of a device equipped with a gear pump according to an embodiment of the present disclosure. [Figure 2] This is an enlarged view of region 2 in Figure 1. [Figure 2A] This is an enlarged view of region 2A in Figure 2. [Figure 3] This is a cross-sectional view showing the flow and mixing profiles of the apparatus of the present invention.

[0006] definition All references to the periodic table refer to the version published by CRC Press, Inc., 1990–1991. References to element groups in this table refer to a new notation used to number the groups.

[0007] For the purposes of U.S. patent practice, the content of any referenced patent, patent application, or publication, in particular with respect to the disclosure of definitions (to the extent that it does not conflict with any definitions specifically provided in this disclosure), is incorporated by reference in its entirety (or its corresponding U.S. version is incorporated by reference in this way).

[0008] Numerical ranges disclosed herein include all values ​​from the lower limit to the upper limit (including the lower and upper limits). In the case of ranges that include explicit values ​​(e.g., 1 or 2, or 3 to 5, or 6, or 7), any subrange between any two explicit values ​​is included (for example, the above range of 1 to 7 includes subranges such as 1 to 2, 2 to 6, 5 to 7, 3 to 7, 5 to 6, etc.).

[0009] Unless otherwise stated, implied by the context, or customary in the art, all parts and percentages are based on weight, and all test methods are current as of the filing date of this disclosure.

[0010] Where used, the terms “blend” or “polymer blend” refer to a mixture of two or more polymers. A blend may or may not be miscible (not phase-separated at the molecular level). A blend may or may not be phase-separated. A blend may or may not contain one or more domain configurations as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and other methods known in the art. A blend may be influenced by the physical mixing of two or more polymers at a macro level (e.g., melt blending or formulation of resins) or at a micro level (e.g., simultaneous formation in the same reactor).

[0011] The term "composition" refers to a mixture of materials that constitute a composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0012] The terms "comprising", "including", "having", and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not they are specifically disclosed. To avoid any ambiguity, all compositions claimed through the use of the term "comprising" may include any additional additives, adjuvants, or compounds, whether polymeric or not, unless the contrary is stated. In contrast, the term "consisting essentially of" excludes from the scope of any preceding description any other components, steps, or procedures, except those that are not essential to the operation. The term "consisting of" excludes any component, step, or procedure not specifically depicted or enumerated. The term "or" refers to the listed members individually and in any combination, unless otherwise stated.

[0013] Ethylene polymers (also referred to interchangeably as polyethylene) are polymers containing units derived from more than half (more than 50 mol%) of ethylene monomers. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include Low Density Polyethylene (LDPE), Linear Low Density Polyethylene (LLDPE), Ultra Low Density Polyethylene (ULDPE), linear low density resins and substantially linear low density resins, single-site catalyst Linear Low Density Polyethylene (m-LLDPE), ethylene plastomers (POP) and ethylene elastomers (POE), Medium Density Polyethylene (MDPE), and High Density Polyethylene (HDPE). These polyethylene materials are generally known in the art. However, the following description may be useful in understanding the differences between some of these different polyethylene resins.

[0014] The term "LDPE" may also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene", but is defined to mean that the polymer is homopolymerized or copolymerized, partially or completely, in an autoclave or tubular reactor at a pressure above 14,500 psi (100 MPa) using a free radical initiator such as peroxide (see, for example, U.S. Patent No. 4,599,392, which is incorporated herein by reference). LDPE resins typically have a density within the range of 0.916 - 0.935 g / cm 3 of.

[0015] The term "LLDPE" includes both resins produced using traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems, as well as single-site catalysts including but not limited to mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), and includes linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPE contains fewer long-chain branches than LDPE and includes substantially linear ethylene polymers as further defined in U.S. Patents 5,272,236, 5,278,272, 5,582,923 and 5,733,155; homogeneously branched linear ethylene polymer compositions such as those in U.S. Patent 3,645,992; heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent 4,076,698; and / or blends thereof (such as those disclosed in U.S. Patents 3,914,342 or 5,854,045). LLDPE can be produced via gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0016] The term "MDPE" refers to 0.926-0.935 g / cm³ 3 This refers to polyethylene having a density of . "MDPE" is typically produced using chromium or Ziegler-Natta catalysts, or single-site catalysts including but not limited to substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), and typically has a molecular weight distribution ("MWD") greater than 2.5.

[0017] The term "HDPE" generally refers to a single-site catalyst prepared using a catalyst including, but not limited to, Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphineimine catalysts, and polyvalent aryloxy ether catalysts (typically referred to as bisphenylphenoxy), at a concentration of approximately 0.935 g / cm³. 3 Super ~ maximum approx. 0.980g / cm 3 This refers to polyethylene having a certain density.

[0018] The term "ULDPE" generally refers to single-site catalysts, including but not limited to Ziegler-Natta catalysts, chromium catalysts, or substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocenes), geometrically constrained catalysts, pyridylamine catalysts, phosphineimine catalysts, and polyvalent aryloxyether catalysts (typically referred to as bisphenylphenoxy), prepared using 0.855–0.912 g / cm³ 3 This refers to polyethylene having a density of 0.855 to 0.912 g / cm³. Examples of ULDPE include, but are not limited to, polyethylene (ethylene-based) plastomers and polyethylene (ethylene-based) elastomers. Polyethylene (ethylene-based) elastomer plastomers generally have a density of 0.855 to 0.912 g / cm³. 3 It has a density of .

[0019] "Olefins" are unsaturated aliphatic hydrocarbons that have a carbon-carbon double bond.

[0020] An "olefin polymer" (commonly referred to as "polyolefin") is a polymer that contains a majority by weight percent of polymerizable olefin monomers (based on the total amount of polymerizable monomers) and may optionally contain at least one comonomer. Non-limiting examples of olefin polymers include ethylene polymers and propylene polymers.

[0021] As used herein, the terms “polymer” or “polymer material” refer to compounds prepared by polymerizing monomers, whether of the same or different types, providing multiple and / or repeating “units” or “mer units” constituting the polymer in a polymeric form. Thus, the general term polymer encompasses the term homopolymer, which is commonly used to refer to polymers prepared from only one type of monomer, and the term copolymer, which is commonly used to refer to polymers prepared from at least two types of monomers. It also encompasses all forms of copolymers, such as random and block copolymers. The terms “ethylene / α-olefin polymer” and “propylene / α-olefin polymer” refer to the aforementioned copolymers and one or more additional polymerizable α-olefin monomers prepared by polymerizing ethylene or propylene, respectively. Polymers are often referred to as "made of" one or more specified monomers, "based on" a specified monomer or type of monomer, or "containing" a specified monomer content. However, it should be noted that in this context, the term "monomer" is understood to refer to the specified monomer of the polymerization residue, and not to the non-polymerized species. In general, polymers as used herein are referred to in terms of "units," which are the polymerization forms of the corresponding monomers.

[0022] A "propylene polymer" (interchangeably referred to as "polypropylene") is a polymer containing more than 50 mole percent of polymerizable propylene monomer (based on the total amount of polymerizable monomers) and optionally containing at least one comonomer. Propylene polymers include propylene homopolymers and propylene copolymers (meaning units derived from propylene and one or more comonomers). The terms "propylene polymer" and "polypropylene" may be used interchangeably. A non-limiting example of a propylene polymer (polypropylene) is at least one C2 or C4-C2 polymer. 10It is a propylene / α-olefin copolymer having an α-olefin comonomer.

[0023] Test method Degree of mixing. The degree of mixing is quantified by the coefficient of variance (CoV) of the local concentration of the second fluid (F2) with respect to the first flow stream (FFS1) on a specific cross-sectional plane. The CoV defined by Equation 1 is calculated in a cross-sectional plane perpendicular to the average flow velocity, where C is the concentration at position r and time t,

[0024]

Number

[0025]

Number

[0026] The density is measured in accordance with ASTM D792, Method B. The results are recorded in grams per cubic centimeter (g) (g / cc or g / cm 3 ).

[0027] The density of the fluid flow stream is measured in accordance with ASTM D792. The results are recorded in grams per cubic centimeter (g) (g / cc or g / cm 3 ).

[0028] The melt index (I2 or MI) is measured in accordance with ASTM D-1238 at 2.16 kg and at 190 °C. The values are reported in g / 10 min corresponding to the grams eluted per 10 minutes.

[0029] Viscosity refers to the resistance of a fluid deformed by either shear stress or tensile stress. For the purposes of this specification, viscosity is measured at 130°C using a Brookfield viscometer measured in accordance with ASTM D445. The results are reported in centipoise (cP). [Modes for carrying out the invention]

[0030] This disclosure provides a process. In embodiments, the process includes providing an apparatus. The apparatus comprises (A) a passage having side walls with an interior for receiving a first flowstream (FFS1). The passage has an opening at the inlet end and an opening at the opposite outlet end. The apparatus comprises (B) a gear pump assembly. The gear pump assembly comprises (i) a housing, (ii) a gear chamber within the housing, (iii) an inlet for fluid communication of the passage with the gear chamber, (iv) a plurality of meshing gears mounted to rotate within the gear chamber, the gears having teeth that engage with each other within the chamber, and (v) an outlet for fluid communication with the gear chamber. The apparatus comprises (C) one or more conduits, each conduit for fluid communication with an outlet and the passage, and each conduit has an outlet duct for fluid communication with the passage. The apparatus comprises (D) injectors in each conduit for adding a second fluid (F2) to each conduit. This process includes introducing a second fluid from each outlet duct into an FFS1 located upstream of the inlet. This process includes supplying the FFS1 and the second fluid into the inlet, mixing the second fluid with the FFS1 in the gear chamber to form a mixed fluid flowstream (mFFS), and discharging the mFFS from the outlet.

[0031] This specification describes the features and operation of embodiments of the present disclosure, with particular reference to the accompanying drawings, which are not intended to limit the scope. In the drawings, the same numbers are used throughout to indicate similar elements of the apparatus (unless otherwise indicated).

[0032] Figures 1 to 3 show a mixing apparatus 10 comprising a gear pump 12, a passage 14, and an outlet barrel 16. The passage 14 has side walls 17, and the passage 14 has a substantially uniform diameter along its length, or a uniform diameter. The side walls 17 may or may not be annular side walls. The passage 14 may or may not include a tapered section 15. If there is no tapered section, the passage 14 has a substantially uniform diameter along its length, or a uniform diameter.

[0033] The apparatus 10 includes a gear pump assembly. A “gear pump” is a positive displacement pump that moves a fluid (or one or more fluids) by repeatedly confining a certain volume using meshing gears within a housing, the meshing gears mechanically transporting the fluid using a circulating pump action. The rotating gears form a fluid seal with the pump housing and generate an attractive force at the pump inlet. The fluid drawn into the pump is confined within the cavity of the rotating gears, and the fluid is then transported to the outlet.

[0034] Figure 2 is an enlarged view of region 2 in Figure 1. Figure 2 shows a gear pump assembly 12. The gear pump assembly 12 includes a housing 18 that defines a gear chamber 20. The gear chamber 20 has an inlet 19. The inlet 19 is an opening in the housing 18 that allows a passage 14 to fluidly communicate with the gear chamber 20. The inlet 19 has an inlet width 21. The inlet width 21 is the longest length of the inlet 19 extending between the opposite sides of the housing 18. If the vertical length of the inlet 19 is not the same as the horizontal length of the inlet 19, the inlet width 21 is the larger of the vertical length or the horizontal length. If the inlet 19 has a circular cross-sectional shape, the inlet width 21 is the diameter of the inlet 19. Since the configuration and shape of the inlet 19 can vary, the length of the inlet width 21 can vary accordingly. In other words, the inlet width 21 may or may not include the total diameter of the meshing gears 22a and 22b, in addition to the small clearance or gap between each gear and the inner wall of the gear chamber 20. The length or extent of the inlet width 21 is interchangeable with "I w It is referred to as "".

[0035] Within the gear chamber 20 are multiple (or two) meshing gears (replaced interchangeably as gear(multiple) or gear(single)), gear 22a and gear 22b. Each gear 22a, 22b has teeth 24. The teeth 24 of gear 22a mesh with (or connect with) the teeth 24 of gear 22b. In this embodiment, gear 22a is the same size and shape as gear 22b, and as a result, gears 22a and 22b each have the same gear diameter 25. As used herein, “gear diameter” is the length of a straight line segment starting from one gear tooth, passing through the axis of rotation, across the gear, and extending to the opposite gear tooth, as shown by the gear diameter 25, and the gear diameter 25 is the straight line segment shown in Figure 2. The gear diameter 25 is interchangeably referred to as “G d The term "gear diameter" is interchangeably referred to as "gear outer diameter" and / or "pitch diameter". Alternatively, gear 22a may have a different size and / or shape from gear 22b. Each gear 22a, 22b is supported by a separate shaft (not shown). Generally, one gear is driven by a motor, which drives the other gear (idler). In embodiments, both shafts may be driven by motors. The shafts are supported by bearings on each side of the casing. Each shaft rotates its respective gear around a rotation axis. Gear 22a rotates around rotation axis 26a, and gear 22b rotates around rotation axis 26b. As each gear 22a, 22b rotates around its respective rotation axis, the teeth 24 are mated, meshed, engaged, or otherwise engaged with each other. As the rotation of the gears continues, the teeth disengage from each other.

[0036] In embodiments, each gear has a helix angle. As used herein, “helix angle” is the angle between the axis of rotation of the gear and the line tangent to one of the teeth, as viewed from the front view of the gear. The helix angle can be between 0° and 45°. In further embodiments, the helix angles of gears 22a and 22b are between 0° and 5°.

[0037] This process involves supplying a first fluid flow stream 34 to a passage 14. The passage 14 has an upstream or inlet end for receiving the first fluid flow stream. The passage 14 has a downstream end, i.e., an outlet end, which is in fluid communication with an inlet 19. As used herein, “fluid flow stream” means a material that is in a fluid state and moves as a stream or otherwise flows. Fluid flow is different from the flow of fine solid particles (e.g., sand injection) because fine solid particles (sand particles) are not in a fluid state. Flow is typically induced and sustained by gravity, but other forms of energy or force can be used to induce flow, for example, from the use of a pump. Non-limiting examples of the first fluid flow stream (compatiblely referred to as “FFS1”) material include polymers in a molten, dissolved, or otherwise flowable state, including polyester, polyamide, polyurethane, polyolefin (polyethylene, polypropylene), poly(ethylene terephthalate), natural rubber, synthetic rubber, EPDM, and combinations thereof. In this embodiment, FFS1 has a viscosity of 0.1 g / 10 min to 1000 g / 10 min, or 0.1 g / 10 min to 100 g / 10 min, or 0.1 g / 10 min to 10 g / 10 min.

[0038] The apparatus 10 includes (C) one or more conduits. Each conduit is in fluid communication with (i) a gear pump outlet 42 (renamed interchangeably as outlet 42) and / or an outlet barrel 16, and (ii) a passage 14. In embodiments, the apparatus 10 includes two conduits 46a, 46b, which are located on either side of the gear pump assembly 12 as shown in Figures 1 and 3. Each conduit 46a, 46b has its own outlet duct 48a, 48b which is in fluid communication with the passage 14.

[0039] Apparatus 10 includes (D) injectors 50a, 50b in each conduit for adding the second fluid (F2) to each conduit. Although Figures 1 and 3 show a single injector in each conduit, it is understood that apparatus 10 may include one or more injectors for introducing the second fluid into FFS1. Apparatus 10 may include one, two, three, four, five, six or more injectors.

[0040] Each injector 50a, 50b is located within each conduit 46a, 46b, and each conduit outlet duct 48a, 48b is located upstream of the gear pump assembly 12. The injectors 50a, 50b are in fluid communication with a source of the second fluid, along with tubes, valves, and pumps for supplying the second fluid to the injectors. Non-limiting examples of materials suitable for the second fluid (interchangeably referred to as "F2") include colorants, pigments, carbon black, crosslinking agents, free radical initiators (peroxides), glass fibers, impact modifiers, antioxidants, surface lubricants, UV light absorbers, metal deactivators, fillers, nucleating agents, stabilizers, flame retardants, and combinations thereof. F2 is a fluid that may or may not contain dispersed solid particles, and it is understood that the viscosity of F2 is lower than the viscosity of FF1. In embodiments, the viscosity of the second fluid is lower than the viscosity of FFS1. In further embodiments, the viscosity of the second fluid is 1 centipoise (cP) to 5000 cP, 1 cP to 1000 cP, 1 cP to 100 cP, or 1 cP to 10 cP.

[0041] In the embodiment, each injector 50a, 50b includes a set of multiple spaced ports extending along a portion of each conduit. Ports are perforated in the wall of each conduit and are in fluid communication with a supply source of the second fluid. The ports discharge or otherwise dispense the second fluid through the conduit wall along the length of each conduit. In the embodiment, the ports discharge a continuous flow of the second fluid through the conduit wall along the length of each conduit 46a, 46b, forming a fluid sheet within each conduit. As used herein, “fluid sheet” is a substantially continuous or continuous fluid body composed of the second fluid located within the FFS1, the body of the fluid sheet having length, width, and height when the FFS1 is viewed from a cross-sectional view of each outlet duct.

[0042] In this embodiment, each outlet duct 48a, 48b upstream of the inlet 19 is at least half the gear diameter (or 0.5G) d They are positioned at a distance of half the gear diameter (or 0.5G). For example, if gear 22a (and / or gear 22b) has a diameter of 32 cm, they are positioned at a distance of half the gear diameter (or 0.5G). d The length is 16 cm. This process involves introducing the second fluid 36 (referred to interchangeably as "F2") into the FFS134 from the inlet 19 upstream to at least half the gear diameter (or 0.5 G). d ), or 1G upstream of entrance 19 d ~5G d , or 1G d ~3G d , or 1.5G d ~3G d This includes introducing at a distance of . In an embodiment, the apparatus 10 includes two injectors, a first injector 50a and a second injector 50b, wherein injector 50a is spaced apart from injector 50b along a passage diameter 56, and each injector 50a, 50b (and passage diameter 56) is at least 0.5G as shown in Figure 2. d It is positioned upstream from entrance 19 by a distance.

[0043] In this embodiment, each outlet duct 48a, 48b has at least an inlet width I upstream of the inlet 19. wThey are positioned at a distance of . In Figure 2, position B indicates where the outlet ducts 48a and 48b introduce the second fluid into passage 14. This process introduces the second fluid 36 (referred to interchangeably as "F2") into FFS134 at least 1I w From entrance 19 upstream for a distance of that length, or 1I w ~5I w , or 1I w ~3I w , or 1.5I w ~3I w This includes introducing the inlet 19 upstream by a certain distance.

[0044] In this embodiment, the process delivers the second fluid 36 (synonymously referred to as "F2") through each outlet duct 48a, 48b to at least 1I of the inlet 19. w This includes introducing it to FFS1 at an upstream location.

[0045] This process includes supplying FFS1 and F2 into the inlet 19 and mixing F236 with FFS134 in the gear chamber 20. FFS134 and F236 enter the gear chamber 20 from the passage 14. The reverse-rotating gears 22a and 22b generate an attractive force in region 4 (see Figure 2), trapping or drawing FFS1 and F2 into the gear chamber 20. As the reverse rotation of gears 22a and 22b continues, FFS1 and F2 stretch in the space 38 between the teeth 24 and the inner wall of the gear chamber 20, as indicated by arrow M in Figure 2. As the gears rotate further, the stretching continues, generating a compressive force in the space 38, and F2 is mixed with FFS1. When the teeth 24 from gear 22a engage (or re-engage) with the teeth 24 from gear 22b in region 5, the captured F2 mixed within the FFS1 is discharged from the gear chamber 20 and exits through outlet 42 as a mixed fluid flowstream 40 (i.e., "mFFS40"). This "suction-extension-compression-discharge" cycle is repeated as gears 22a and 22b continue to rotate in opposite directions, with the suction force capturing new amounts of FFS134 and F236 between the meshing teeth and the inner wall of the gear chamber, and the cycle continues.

[0046] This process includes discharging the mFFS 40 from outlet 42. From the gear pump outlet 42, the mFFS 40 flows into outlet barrel 16 for further processing and / or handling.

[0047] Although not bound by any particular theory, the applicant found that by introducing a second fluid through conduits 46a and 46b, the need for conduits running through and extending within the passage is eliminated. The applicant further added at least 0.5G upstream of the inlet 19. d (or at least one I w It was discovered that introducing a second fluid into the FFS1 at a distance of ) unexpectedly creates or defines a recirculation zone in the passage 14 (or tapered section). As used herein, “recirculation zone” means a volumetric portion within the passage 14 (or volumetric portion within the tapered section) whose downstream end is defined by a plane surrounding the inlet 19 and whose upstream end is at least 0.5G from the inlet 19 d (or at least one I w The recirculation zone is defined by a plane surrounding an elongated conduit located upstream of the inlet 19 at a distance from the inlet 19, and the rotation of gears 22a and 22b generates (i) layer flow streams of FFS1 and the second fluid, and (ii) vortex flow streams of FFS1 and the second fluid within the volumetric portion. The recirculation zone performs two actions: (1) The recirculation zone moves the incoming second fluid sheet (F2) to the low-pressure zone at the apex of the gear meshing zone. (2) The recirculation zone enhances the mixing of the second fluid sheet (F2) so that a portion of the second fluid F2 is first mixed within the recirculation zone and then enters the gear chamber 20.

[0048] In this embodiment, the process includes forming a laminar flow stream through the gear chamber 20. As used herein, “laminar flow stream” is a flow in which small turbulence in the form of vortices or eddies does not have enough energy to sustain its state, where vortices or eddies dissipate instantaneously, and laminar flow is not suitable for turbulent flow. The laminar flow stream includes portions of FFS1 and F2 flowing around and through the meshing gears 22a and 22b, as indicated by arrow M in Figure 2.

[0049] In embodiments, this process further includes forming a vortex flow stream within a recirculation zone. As used herein, “vortex flow stream” is a flow stream within a recirculation zone in which a portion of FFS1 and / or F2 rotates around an axis to generate a vortex. The recirculation zone (composed of FFS1 and F2) is located within a passage, the downstream end of the recirculation zone is in contact with the top of a gear tooth, the passage sidewall is in contact with another side, the upstream end of the recirculation zone is defined by the position of the injector, the injector is at least 0.5G upstream from the inlet 19 d (or at least 1I w The distance between the two is ). The upstream end of the recirculation zone remains open to the viscous flows of FFS1 and FFS2, as indicated by arrow 1 in Figures 1 and 2. The gear pump assembly 12, with two gears rotating in opposite directions, forms two recirculation zones, each with its own distinct vortex flow, and each recirculation zone is located upstream of its respective gears 22a and 22b (see Figures 2 and 3).

[0050] Each conduit 46a, 46b includes its respective inlet duct 49a, 49b. Each inlet duct 49a, 49b is in fluid communication with the gear pump outlet 42 and / or outlet barrel 16. As the mFFS 40 is discharged from the outlet 42 and flows out, each inlet duct 49a, 49b is configured to receive a fraction of the mFFS 40 from the outlet 42 and lead this fraction of the mFFS to its respective conduit 46a, 46b. Each inlet duct 49a, 49b draws a portion of the mFFS 40 from the outlet 42 into its respective conduit 46a, 46b, as indicated by arrow C in Figure 3. The majority of the flow of the mFFS 40 continues downstream through the outlet barrel 16, as indicated by arrow D in Figure 3.

[0051] In this embodiment, the process includes receiving a portion of the mFFS 40 from outlet 42 (and / or outlet barrel 16) into each inlet duct 49a, 49b as a recirculated mixed fluid flowstream 52a, 52b (or "r-mFFS"), and adding a second fluid F2 to each r-mFFS 52a, 52b in each conduit 46a, 46b, as shown in area E of Figure 3, to injectors 50a, 50b. The process includes introducing each r-mFFS 52a, 52b and F2 into passage 14 through their respective outlet ducts 48a, 48b, as indicated by arrow F in Figure 3. This process includes mixing r-mFFS52a, 52b with FFS1 and a second fluid F2 in the gear chamber, and forming a composite mixed FFS54 consisting of (i) mFFS40, (ii) r-mFFS52a, 52b, and (iii) F2. The composite mixed FFS54 has a CoV of 0.001 to 0.8, or 0.1 to 0.5. This process includes discharging the composite mixed FFS54 from outlet 42 (and / or outlet barrel 16).

[0052] In this embodiment, the process delivers each r-mFFS52a, 52b, the second fluid, and FFS1 to at least one I inlet 19. w (2) The fluid is introduced into the passage 14 at a distance upstream, thereby introducing each of the r-mFFS 52a, 52b, the second fluid, and FFS1 into the recirculation zone. The recirculation zone moves each of the r-mFFS 52a, 52b, the second fluid, and FFS1 into the low-pressure zone at the apex of the gear meshing zone. (3) The recirculation zone enhances the mixing of each of the r-mFFS 52a, 52b, the second fluid, and FFS1, as a portion of the second fluid F2 is first mixed in the recirculation zone and then enters the gear chamber 20.

[0053] In this embodiment, each conduit 46a, 46b includes a flow control valve 56 for moving their respective r-mFFS 52a, 52b from the inlet duct to the outlet duct, as shown in Figure 1.

[0054] This disclosure advantageously provides a process for mixing a second fluid (F2), such as an additive, into a polymer melt stream (FFS1) without using an extruder and a static mixer. In embodiments, the process is achieved by utilizing a liquid additive injector system installed in a conduit that carries the polymer flow to a gear pump. This disclosure further provides a specific gear profile for achieving effective mixing. The desired mixing is achieved by utilizing the shear and mixing provided by the gear pump.

[0055] This disclosure is not limited to the embodiments and examples contained herein, but is specifically intended to include, to the extent applicable to the following claims, modified forms of those embodiments, including parts of the embodiments and combinations of elements of different embodiments.

Claims

1. It is a process, To provide an apparatus, (A) A passage having side walls with an interior for receiving a first flowstream (FFS1), the passage having an inlet end and an outlet end opposite to the passage, (B) Gear pump assembly, (i) Housing and (ii) The gear chamber within the housing, (iii) An inlet that connects the outlet end of the passage to the gear chamber, (iv) A plurality of meshing gears mounted to rotate within the gear chamber, each having teeth that engage with each other within the chamber, and (v) A gear pump assembly including an outlet that is in fluid communication with the gear chamber, (C) One or more conduits, the conduits extending along the opposite side of the gear pump assembly, each conduit having fluid communication with the outlet and the passage, and each conduit having an outlet duct having fluid communication with the passage, (D) An injector in each conduit for adding a second fluid (F2) to each conduit, The aforementioned process, The second fluid from each outlet duct is introduced into the FFS1 at a position upstream of the inlet, The FFS1 and the second fluid are supplied into the inlet, Within the gear chamber, the second fluid is mixed with FFS1 to form a mixed fluid flow stream (mFFS), A process comprising discharging the mFFS from the outlet.

2. Each conduit includes an inlet duct that is in fluid communication with the outlet, and the process is, From the aforementioned outlet, a portion of the mFFS is received into each inlet duct as a recirculated mixed fluid flowstream (r-mFFS), The process according to claim 1, comprising adding the second fluid to each r-mFFS in each conduit.

3. Introducing the r-mFFS and the second fluid into the passage, In the gear chamber, the r-mFFS is mixed with the FFS1 and the second fluid, (i) to form a composite mixed FFS including the mFFS and (ii) the r-mFFS, The process according to claim 2, further comprising discharging the composite mixed FFS from the outlet.

4. Each gear has a gear outer diameter, and the passage includes a recirculation zone defined by a passage volume portion from the inlet to a distance upstream of at least half the gear diameter, and the process is, The process according to any one of claims 1 to 3, comprising forming vortex flows of the FFS1, F2, and r-mFFS within the recirculation zone.

5. Each conduit includes a plurality of ports spaced apart along the side wall of each conduit, and the process is, The process according to any one of claims 1 to 4, comprising discharging the second fluid from the port.

6. The aforementioned entrance has a width (I ｗ ) has, and the passage is I ｗ Having an upstream end with a larger diameter, ｗ The method includes a tapered section that decreases to a downstream end having the following diameter, The outlet duct for each conduit is positioned at the upstream end of the tapered section, The second fluid from each of the aforementioned conduits is passed through at least one inlet width (I ｗ The process according to any one of claims 1 to 5, comprising introducing the FFS1 at an upstream position.

7. The process according to any one of claims 1 to 6, comprising forming a composite mixed FFS having a coefficient of variation of 0.001 to 0.8.

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