Mixing process of a fluid melt flow stream

Abstract

This disclosure provides a process. In one embodiment, the process includes providing an apparatus. The apparatus includes (A) a passage having side walls having an interior for receiving a first flowstream (FFS1), and the passage having an inlet end and an outlet end on the opposite side. The apparatus includes (B) a gear pump assembly. The gear pump assembly includes (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 each gear having a pivot axis, and (v) an outlet for fluid communication with the gear chamber. The apparatus includes (C) one or more injectors upstream of the gear pump assembly for adding a second fluid to the first flowstream (FFS1). Each injector is located in a side wall. The process includes introducing the second fluid into the FFS1 from each injector located in its respective side wall, and supplying the FFS1 and the second fluid into the inlet. This process includes mixing a second fluid with FFS1 in a gear chamber to form a mixed fluid flow stream (mFFS), and discharging the mFFS from an outlet.

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 the flow of the polymer melt stream in this process is typically laminar, without a spontaneous mixing mechanism. The high viscosity of the polymer melt stream 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 drop in the polymer melting flow production process. The pressure drop resulting from the addition of static mixers to the flow process can lead to a potential dead zone in the production flow stream. This dead zone can lead to long-term degradation of the polymer melting stream flow 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 Initiative]

[0004] This disclosure provides a process. In one embodiment, the process includes providing an apparatus. The apparatus includes (A) a passage with side walls having an interior for receiving a first flow stream (FFS1), and the passage having an inlet end and an outlet end on the opposite side. The apparatus includes (B) a gear pump assembly. The gear pump assembly includes (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 each gear having a pivot axis, and (v) an outlet for fluid communication with the gear chamber. The apparatus includes (C) one or more injectors upstream of the gear pump assembly for adding a second fluid to the first flow stream (FFS1). Each injector is located in the side wall. This process includes introducing a second fluid into the FFS1 from injectors positioned on each side wall, and supplying the FFS1 and the second fluid into the inlet. This process also includes 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. [Brief explanation of the drawing]

[0005] [Figure 1] This is a cross-sectional view of a device equipped with a gear pump according to one embodiment of the present disclosure. [Figure 2] This is an enlarged view of region 2 in Figure 1. [Figure 3A] Figure 1 is an exploded perspective view of the apparatus, showing a fluid sheet according to one embodiment of the present disclosure. [Figure 3B] This is a cross-sectional view of region 3B in Figure 3A. [Figure 4A] Figure 1 is a cross-sectional view of the apparatus, showing alternative locations for the injector within the apparatus's passage. [Figure 4B]Figure 4A is a cross-sectional view of the apparatus showing the flow and mixing profiles corresponding to the injector position. Figures 4B to 4E also show cross-sectional views of the obtained mixed fluid flowstream and corresponding CoV values ​​for each of the flow and mixing profiles. [Figure 4C] Figure 4A is a cross-sectional view of the apparatus showing the flow and mixing profiles corresponding to the injector position. Figures 4B to 4E also show cross-sectional views of the obtained mixed fluid flowstream and corresponding CoV values ​​for each of the flow and mixing profiles. [Figure 4D] Figure 4A is a cross-sectional view of the apparatus showing the flow and mixing profiles corresponding to the injector position. Figures 4B to 4E also show cross-sectional views of the obtained mixed fluid flowstream and corresponding CoV values ​​for each of the flow and mixing profiles. [Figure 4E] Figure 4A is a cross-sectional view of the apparatus showing the flow and mixing profiles corresponding to the injector position. Figures 4B to 4E also show cross-sectional views of the obtained mixed fluid flowstream and corresponding CoV values ​​for each of the flow and mixing profiles. [Figure 5] This is a side view of a device equipped with a tapered portion according to one embodiment of the present disclosure.

[0006] definition Any reference to the periodic table refers to the version published by CRC Press, Inc., 1990–1991. References to element groups in this table refer to a new notation for numbering 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] The numerical ranges disclosed in this specification include all values from the lower limit to the upper limit (including the lower and upper limits). In the case of a range including explicit values (e.g., 1 or 2, or 3 to 5, or 6, or 7), any sub-range between any two explicit values is included (e.g., in the range of 1 to 7 above, sub-ranges such as 1 to 2, 2 to 6, 5 to 7, 3 to 7, 5 to 6, etc. are included).

[0009] Unless otherwise indicated, unless implied from the context, or unless not customary in the art, all parts and percentages are by weight, and all test methods are the latest as of the filing date of this disclosure.

[0010] When used, the terms "blend" or "polymer blend" refer to a mixture of two or more polymers. A blend may be miscible or immiscible (not phase-separated at the molecular level). A blend may be phase-separated or not phase-separated. A blend may or may not contain one or more domain structures determined from transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. A blend can be affected by physically mixing two or more polymers at the macro level (e.g., melt blending or compounding of resins) or at the micro level (e.g., simultaneous formation in the same reactor).

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

[0012] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the existence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may, unless otherwise stated, include any additional additives, adjuvants, or compounds, whether or not they are polymers. In contrast, the term “consisting essentially of” excludes any other components, processes, or procedures from the scope of any prior description, except those not essential for operability. The term “consisting of” excludes any components, processes, or procedures that are not specifically described or enumerated. The term “or” refers to the enumerated 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 (over 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), single-site catalyst linear low density polyethylene (m-LLDPE) including both linear low density resins and substantially linear low density resins, 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 helpful in understanding the differences among 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, either 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 single-site catalysts, including but not limited to traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems, as well as 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. LLDPEs include substantially linear ethylene polymers containing fewer long-chain branches than LDPEs, 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). LLDPEs 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 a chromium or Ziegler-Natta catalyst, or a single-site catalyst, 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 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 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 these catalysts in a concentration of 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]

Number

[0027]

Number

[0028] 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 ).

[0029] The fluid flow stream density is measured according to ASTM D792, Method B. The results are expressed in grams per cubic centimeter (g) (g / cc or g / cm³). 3 ) is recorded.

[0030] The melt index (I2 or MI) is measured according to ASTM D-1238 at 2.16 kg and 190°C. The value is reported as g / 10 min, corresponding to the grams eluted per 10 minutes.

[0031] 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]

[0032] This disclosure provides a process. In one embodiment, the process includes providing an apparatus. The apparatus includes (A) a passage with side walls having 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 includes (B) a gear pump assembly. The gear pump assembly includes (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 includes (C) one or more injectors located upstream of the gear pump assembly for adding a second fluid to the first flowstream. Each injector is located in the side wall. The process includes introducing the second fluid into the FFS1 from each of the injectors located in their respective side walls. This process includes supplying FFS1 and a second fluid into the inlet, mixing the second fluid with FFS1 in the gear chamber to form a mixed fluid flowstream (mFFS), and discharging the mFFS from the outlet.

[0033] 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).

[0034] Figures 1 and 2 show a mixing apparatus 10 having a gear pump 12, a passage 14, and an outlet barrel 16. The passage 14 has a substantially uniform diameter along its length, or a passage 14 with side walls 17 having a uniform diameter along its length. The side walls 17 may or may not be annular side walls. The passage 14 may or may not include a tapered section 15, as disclosed below. If there is no tapered section, the passage 14 has a substantially uniform diameter along its length, or a uniform diameter along its length.

[0035] 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.

[0036] Figure 1 is a cross-sectional view of the apparatus 10. Figure 1 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 "...".

[0037] Within the gear chamber 20 are multiple (or two) meshing gears (referred interchangeably to 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 one 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. Alternatively, gear 22a may have a different size and / or shape than 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 one embodiment, 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 its axis of rotation. Gear 22a rotates around axis 26a, and gear 22b rotates around axis 26b. As each gear 22a, 22b rotates around its respective axis of rotation, 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.

[0038] In one embodiment, 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 a further embodiment, the helix angles of gears 22a and 22b are between 0° and 5°.

[0039] This process involves supplying a first fluid flow stream 34 (shaded gray area in Figure 1) into 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 differs 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 one 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.

[0040] The apparatus 10 includes one or more injectors 50 for introducing a second fluid into the FFS1. The apparatus 10 may include one, two, three, four, five, six, or more injectors 50. The injectors 50 are located upstream of the gear pump assembly 12. The injectors 50 are in fluid communication with a supply source for the second fluid, along with piping, valves, and pumps for supplying the second fluid to the injectors 50. 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, which may or may not contain dispersed solid particles, and it is understood that F2 has a viscosity lower than that of FF1. In one embodiment, the second fluid has a viscosity lower than that of FFS1. In a further embodiment, the second fluid has a viscosity of 1 centipoise (cP) to 5000 cP.

[0041] Each injector 50 includes a set of several spaced-apart portion ports 54 extending along a portion of the side wall 17. The ports 54 are drilled through the side wall 17 and are in fluid communication with a supply source of a second fluid. The ports 54 discharge the second fluid along and through the length of the side wall 17, or otherwise distribute it. In one embodiment, the ports 54 discharge a continuous flow of the second fluid through the side wall 17 and along the length of the side wall 17 forming a fluid sheet. As used herein, “fluid sheet” is a substantially continuous or continuous fluid body composed of the second fluid arranged within the FFS 1, the body of the fluid sheet having length, width, and height when the FFS 1 is viewed from a cross-sectional view downstream of an elongated conduit. Figure 3A is an exploded perspective view of the apparatus 10 with the passage 14 and housing 18 removed, and shows the fluid sheets 60a, 60b formed from the respective injectors 50a, 50b (each injector has its own set of spaced-apart ports 54) on the opposite side of the side wall 17. Figure 3A shows the fluid sheets 60a, 60b, each having its own body 62, each body 62 being a continuous volume of F2, and each body 62 having dimensions of length (L), width (W), and height (H).

[0042] Returning to Figure 1, in one embodiment, the injector 50 has at least an inlet width (I) upstream of the inlet 19. w The fluid is positioned at a distance of ). This process introduces the second fluid 36 (referred to interchangeably as "F2") into the FFS1 34, at least 1 I upstream from the inlet 19. w , or upstream of entrance 19, 1 w ~5 I w , or 1 I w ~3 I w , or 1.5 I w ~3 I wThis includes introducing at a distance of 1 l. In one embodiment, the apparatus 10 includes two injectors, a first injector 50a and a second injector 50b, where injector 50a is on one side of the side wall 17 and injector 50b is on the opposite side of the side wall 17, each injector 50a, 50b has a set of spaced-apart ports 54 extending through the side wall, and each injector 50a, 50b is 1 l upstream from the inlet 19 as shown in Figure 1. w They are placed at a distance from each other.

[0043] This process involves introducing a second fluid 36 (referred to interchangeably as "F2") through one or more injectors, each injector located on the side wall 17 and extending at least 1 upstream from the inlet 19. w Install it into FFS1 at this location.

[0044] This process includes supplying FFS1 and F2 into the inlet 19 and mixing F2 36 with FFS1 34 in the gear chamber 20. FFS1 34 and F2 36 enter the gear chamber 20 from the passage 14. The reverse-rotating gears 22a and 22b generate an attractive force in region 4 that traps or otherwise pulls 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 1. Further rotation of the gears continues the stretching, generating a compressive force in the space 38 and mixing F2 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 FFS1 is discharged from the gear chamber 20 and exits through outlet 42 as a mixed fluid flowstream 40 (or "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 FFS1 34 and F2 36 between the meshing teeth and the inner wall of the gear chamber, and the cycle continues.

[0045] This process includes discharging the mFFS 40 from outlet 42. From outlet 42, the mFFS 40 flows into outlet barrel 16 for further processing and / or handling.

[0046] While not bound by any particular theory, the applicant found that by introducing a second fluid through a port in the side wall, the need for a conduit running through and extending into the passage is eliminated. The applicant introduced the second fluid into the FFS1, at least 1 upstream of the inlet 19. w We further found that introducing the water at a certain distance unexpectedly creates or otherwise defines a recirculation zone within the passage 14 (or alternatively, within the tapered section). As used herein, “recirculation zone” means the downstream end defined by the plane encompassing the inlet 19 and at least 1 I w This is a volumetric portion within the passage 14 (or volumetric portion within the tapered section) having an upstream end defined by a plane encompassing an elongated conduit located at a distance and upstream of the inlet 19. The rotation of gears 22a and 22b generates (i) laminar flow streams of FFS1 and the second fluid, and (ii) eddy 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 top of the gear meshing zone, and (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 in the recirculation zone and then enters the gear chamber 20.

[0047] In one embodiment, this process includes forming a laminar flow stream through the gear chamber 20. As used herein, “laminar flow stream” means 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 through and around the meshing gears 22a and 22b, as indicated by arrow M in Figures 1 and 2.

[0048] In one embodiment, the process also includes forming a vortex flow stream within a recirculation zone. As used herein, “vortex flow stream” is a flow stream within a recirculation zone that includes a portion of FFS1 and / or a portion of F2, which rotates around an axis to generate a vortex. The recirculation zone (consisting of FFS1 and F2) is defined such that 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, and the upstream end of the recirculation zone is defined by the position of the injector, with the injector extending at least 1 I upstream from the inlet 19. w It is positioned within the passage at a distance from each other. The upstream end of the recirculation zone remains open to the viscous flows of FFS1 and FFS2, as indicated by arrow 1 in Figure 1. The gear pump assembly 12, having two gears rotating in opposite directions to each other, generates two recirculation zones, each containing a separate discrete vortex flow, and each recirculation zone is located upstream of its respective gears 22a and 22b, as shown in Figures 1 and 3B.

[0049] In one embodiment, the apparatus 10 includes a first injector 50a and a second injector 50b, as shown in Figure 3A. Each injector includes a set of ports 54 for discharging the second fluid 36 into the FFS1 34 as a first flow sheet 60a and a second flow sheet 60b, respectively. The first injector 50a is located on one side of the side wall 17, and the second injector 50b is located on the opposite side of the side wall 17, with the injector 50a spaced at a distance equal to or substantially equal to the diameter of the passage 14 from the second injector 50b. The injectors 50 extend at least 1 I upstream from the inlet 19. w They are positioned at a distance from each other, thereby defining the recirculation zone. This process involves introducing the second fluid from each elongated conduit (towards port 54) and placing each of the first flowsheet 60a and second flowsheet 60b into the FFS1, at least 1 upstream of the inlet 19. wThis process includes forming at the location of the first recirculation zone 70a and the second recirculation zone 70b, respectively, as shown in Figure 1. This process includes supplying the FFS1 34 and flow sheets 60a, 60b into the inlet 19, mixing the second fluid 36 with the FFS1 34 in the gear chamber 20 to form a mixed fluid flowstream 40 (mFFS 40), discharging the mFFS 40 from the outlet 42, and forming the mFFS 40 having a CoV of 0.001 to 0.8 or 0.1 to 0.5.

[0050] For evaluation purposes, Figures 4A to 4E show the device 10 with injectors and the gear pump assembly 12 at different locations within the passage 14. In Figure 4A, position B is on the side opposite the side wall 17 and upstream of the inlet 19. w The diagram shows two injectors located at a distance of 1. Position C is upstream of inlet 19. w A single injector is shown in the gear chamber 20 at a distance of less than 1. Position D is in space 38 and 1 I upstream from the inlet 19. w The diagram shows two injectors in the gear chamber 20, located at a distance of less than 1. Position E shows a single injector in the passage 14, upstream of the inlet 19. w It is less than a certain distance away.

[0051] Figure 4B shows the flow and mixing profiles of the two injectors at position B in Figure 4A, and a cross-sectional view of the mFFS 40 is taken along line 4B-4B. The laminar flow M and eddy flow N form an mFFS with a CoV of 0.36. Figure 4B, with the injectors at position B, is an example of the present disclosure.

[0052] Figure 4C shows the flow and mixing profiles of a single injector at position C in Figure 4A, and a cross-sectional view of the mFFS 40 is taken along line 4C-4C. The laminar flow M and non-edgy flow N form an mFFS with a CoV of 0.61. Figure 4C, with a single injector at position C, is a comparative sample of the present disclosure.

[0053] Figure 4D shows the flow and mixing profiles of the two injectors at position D in Figure 4A, and a cross-sectional view of the mFFS 40 is taken along line 4D-4D. The laminar flow M and non-edgy flow N form an mFFS with a CoV of 0.54. Figure 4D, with the two injectors at position D, is a comparative sample of the present disclosure.

[0054] Figure 4E shows the flow and mixing profiles of a single injector at position E in Figure 4A, and a cross-sectional view of the mFFS 40 is taken along line 4E-4E. The laminar flow M and eddy flow N form an mFFS with a CoV of 0.89. Figure 4E, with a single injector at position E, is a comparative sample of the present disclosure.

[0055] Figure 5 shows an embodiment of the device 10 having a tapered section 15 that is in fluid communication with the passage 14 and located upstream of the gear assembly 12. The tapered section 15 is in fluid communication with the gear chamber 20.

[0056] In one embodiment, the device 10 includes a tapered section 15. The tapered section 15 is an annular body 28 having an upstream end 30 with a diameter larger than the length of the inlet width 21. The tapered section 15 has a downstream end 32 with a diameter that is the length of the inlet width 21. In other words, the diameter of the downstream end 32 is the same as, or substantially the same as, the inlet width 21.

[0057] As the tapered section 15 moves from the upstream end 30 to the downstream end 32, it has a body 28 having a diameter that gradually decreases or otherwise gradually decreases, while contracting the internal volume within the tapered section 15. Thus, the tapered section 15 has an upstream diameter greater than the inlet width and decreases to a downstream end having a diameter equal to, substantially equal to, or smaller than the inlet width. The contracted diameter of the tapered section 15 increases the pressure of the fluid flowstream as the fluid flowstream enters the gear chamber 20. In one embodiment, this process includes positioning or otherwise installing a set of injector ports through the body 28 at the upstream end of the tapered section. The second fluid is then introduced into the FFS1 from each respective injector through at least one inlet width (I) upstream of the inlet. w The process includes introducing the fluid at the position of the inlet 19, supplying the FFS1 and the second fluid into the inlet 19, mixing the second fluid with the FFS1 in the gear chamber to form a mixed fluid flow stream (mFFS), and discharging the mFFS from the outlet. In a further embodiment, this process includes forming an mFFS having a CoV of 0.1 to 0.5.

[0058] 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 one embodiment, the process is achieved by utilizing a liquid additive injector system located in a conduit that carries the polymer flow to a gear pump. This disclosure also 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.

[0059] Examples of embodiments of the present disclosure are provided below, but are not limited to the above. [Examples]

[0060] Table 1 below shows the materials used in the examples.

[0061] [Table 1]

[0062] In one embodiment, apparatus 100 is provided as shown in Figure 5. Apparatus 100 is similar to apparatus 10 (disclosed earlier), and apparatus 100 includes a tapered section 15 and / or alternative components for evaluating mixing performance.

[0063] The injector 50 is drilled into the body 28 and includes several spaced-out portion ports (29 inches in diameter) extending along the body 28. The apparatus 100 may also include a source of F2, along with piping, valves, and a pump for supplying F2 to the injector 50. In the case of apparatus 100, the distance between the rotating shaft 26a and the injection conduit 52 is 7.6 inches. In the case of apparatus 100, the outlet barrel 16 is 18 inches long.

[0064] For evaluation purposes, the wall injector port 54 is drilled along the body 28 of the tapered section 15, which is parallel to the rotation axis of the gear.

[0065] In apparatus 100, the pitch diameter of each gear is 12.8 inches with a helix angle of 30°. In the gear chamber 20, both (i) the intertooth clearance and (ii) the clearance between the gear tip and the housing are maintained at 0.022 inches.

[0066] Table 2 below shows the CoV values ​​in the cross-sectional plane at the outlet barrel 16 of the mFFS 40. The flow through the apparatus 100 is simulated using a modeling technique called Computational Fluid Dynamics (CFD). The CoV values ​​in Table 2 below are generated using CFD (Starccm+V15) and a meshing tool (SCORG). CFD simulates the flow and mixing of additives through the polymer molten material and across the gear teeth. The CoV is calculated using the additive concentrations across the cross-sectional plane at the outlet, based on equations 1-3 (CoV) for the degree of mixing described earlier.

[0067] The CoV value is calculated across a cross-section perpendicular to the flowstream. As previously mentioned, CoV calculates the ratio of the standard deviation to the mean concentration of the second fluid (F2). The standard deviation and mean concentration values ​​are calculated based on the results of a CFD simulation under the previously mentioned operating conditions. The simulation is run to achieve steady-state conditions where the mean and standard deviation of the concentration values ​​across different cross-sectional planes no longer change. Since the CFD simulation retains details of the velocity, pressure, temperature, and concentration values ​​in each calculation cell, the standard deviation and mean concentration values ​​for a given cross-section can be calculated.

[0068] [Table 2]

[0069] For this application as a fluid additive to FFS1 (LDPE), a CoV of 0.01 to 0.5 is considered appropriate. A wall injector yields a CoV of 0.4, thereby providing an acceptable mixture.

[0070] This disclosure is not limited to the embodiments and examples contained herein, but is specifically intended to include some embodiments and modified forms of those embodiments, including combinations of elements of different embodiments, to the extent that they fall within the scope of the following claims.

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 on the opposite side, (B) Gear pump assembly, (i) Housing, (ii) Gear chamber within the housing, (iii) An inlet that connects the passage to the gear chamber in fluid communication, (iv) A plurality of meshing gears mounted to rotate within the gear chamber, wherein each gear has teeth that engage with each other within the chamber, and each gear has a rotation axis, and (v) A gear pump assembly including an outlet that is in fluid communication with the gear chamber, (C) To provide an apparatus for adding a second fluid into the first flowstream (FFS1), wherein each injector comprises one or more injectors located upstream of the gear pump assembly, the injectors comprising one or more injectors positioned on the side wall, The aforementioned process, The second fluid is introduced into the FFS1 from injectors, each of which is positioned on the respective side walls. 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 flowstream (mFFS), A process comprising discharging the mFFS from the outlet.

2. The aforementioned entrance has a width (I ｗ ) has, and the passage extends upstream from the entrance, I ｗ The distance includes a recirculation zone defined by the volume portion of the passage, and the process is, The second fluid is introduced into the FFS1 from each injector through at least one inlet width (I) upstream of the inlet. ｗ It should be introduced at the position of, The process according to claim 1, further comprising forming vortex flows of FFS1 and F2 within the recirculation zone.

3. Each injector includes a set of multiple ports spaced apart along the length of the side wall, and the process is, Discharging the second fluid from the port, The process according to claim 1 or 2, comprising forming a fluid sheet within the FFS1, wherein the fluid sheet is composed of the second fluid.

4. The apparatus includes a first injector and a second injector spaced apart on the side opposite the side wall, each injector having a set of ports spaced apart along a portion of the side wall, and the process is, A first fluid sheet is formed in the FFS1 from the first injector, and a second fluid sheet is formed from the second injector. The process according to claim 3, comprising forming a first vortex flow within the recirculation zone, comprising a portion of the FFS1 and the first fluid sheet, and forming a second vortex flow comprising a portion of the FFS1 and the second fluid sheet.

5. The aforementioned passage is I ｗ Having an upstream end with a larger diameter, ｗ The process includes a tapered section that reduces to a downstream end having a diameter less than or equal to the following, Positioning the injector at the upstream end of the tapered portion, The second fluid is introduced into the FFS1 from each of its elongated conduits through at least one inlet width (I) upstream of the inlet. ｗ The process according to claim 1 or 2, comprising introducing at the position of ).

6. The process according to any one of claims 1 to 5, comprising forming an mFFS having a coefficient of variation of 0.001 to 0.8.

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