Fluids impacting reactor (FIRE)

Abstract

A mixing unit for a fluidic device is provided. The mixing unit comprises a reactant passage segment that extends substantially along a first axis (152) within a portion of the fluidic device. The reactant passage segment comprises a mixing portion (164) that adjoins a segment inlet (156) and a retention portion (168) that is fluidically connected to the mixing portion and adjoins a segment outlet (160) disposed downstream from the segment inlet in a flow direction of the reactant passage segment. The mixing portion comprises a wall structure (172) configured to split the reactant passage segment into at least two sub-passages (176). The mixing portion also comprises a mixing chamber (188) into which each of the at least two sub-passages opens through a nozzle (192). The nozzles are spaced apart about the mixing chamber and oriented such that respective facing directions of the nozzles substantially intersect at an impingement point (200).

Description

SP24-273FLUIDS IMPACTING REACTOR (FIRE)CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Serial No. 63 / 726722 filed on December 2, 2024, the content of which is relied upon and incorporated herein by reference in its entirety.FIELD

[0002] The present disclosure relates generally to continuous-flow micro / milli -reactors. In particular, the present disclosure relates to the mixing units (micromixers) of such reactors having features that allow for high mixing effectiveness with controlled pressure drop.BACKGROUND

[0003] Continuous-flow micro / milli-reactors are becoming an established attractive choice for the continuous manufacturing of chemicals and pharmaceuticals. The micro -reaction technology used by such reactors offers advantages such as fast heat and mass transfer and inherent safety, due to the small characteristic dimensions of the microreactors. In a microreaction system, the mixing units (also referred to as micromixers) are key components. Fast chemical reactions controlled predominantly by kinetics are sensitive to the mixing behavior inside the continuous-flow chemical reactor. Poor mixing performance can lead to undesired side reactions, which can negatively affect the product yield and / or the productivity. In microreactors, the small channel dimensions often result in a laminar flow regime where transport phenomena can be limited by the diffusion.

[0004] Applicant has developed the Advanced -Flow™ Reactor (AFR) with intensified mixing behavior and enhanced heat transfer capability. Aspects of the AFR technology are described in U.S. Pat. No. 7,939,033, which is incorporated herein by reference in its entirety. The mixing unit in this patent comprises a heart-shape, 2D geometry that is based on the Split- And-Recombine (SAR) principle. FIGS. 22-24 illustrate aspects of the mixing units disclosed in U.S. Pat. No. 7,939,033. FIG. 22 shows a three-dimensional perspective view of a portion of a process fluid passage according to an existing flow reactor. FIG. 23 shows an individual mixing unit / chamber of the passage of FIG. 22. FIG. 24 shows, in perspective view, a crosssection of the mixing unit / chamber of FIG. 23.SP24-273

[0005] With respect to FIGS. 22-24, a flow reactor of the general type disclosed herein comprises a module having a process fluid passage 20 therein. The process fluid passage comprises an interior surface 22. The process fluid passage 20 further comprises a portion 30 thereof, which portion further comprises an input end 32 at which process fluid is to flow into the portion 30 during use and an output end 34 at which process fluid is to flow out of the portion 30 during use. The portion 20 also comprises a cross section 36 along the portion 30, which is delimited by the interior surface 22 of the passage 20 along the portion 30. The cross section 36 has a cross-sectional area and a cross-sectional shape 38. The cross-sectional area has multiple minima 40 along the passage 20 between the input end 32 and the output end 34.

[0006] The flow reactor of U.S. Pat. No. 7,939,033 has a characteristic passage design and produces good mixing performance relative to pressure drop in a given channel or device. It would be desirable to achieve even better performance, however, such as equal or better mixing with lower pressure drop.SUMMARY

[0007] The following summary is a brief description of certain aspects of the present disclosure. The summary should not be considered as limiting of the breadth, scope, or applicability of the present disclosure.

[0008] A first aspect of the present disclosure includes a mixing unit for a fluidic device comprising: a reactant passage segment extending substantially along a first axis within a portion of the fluidic device, the reactant passage segment comprising a mixing portion that adjoins a segment inlet and a retention portion that is fluidically connected to the mixing portion and adjoins a segment outlet disposed downstream from the segment inlet in a flow direction of the reactant passage segment, the mixing portion comprising (i) a wall structure configured to split the reactant passage segment into at least two sub-passages and (ii) a mixing chamber into which each of the at least two sub-passages opens through a nozzle, the nozzles spaced apart about the mixing chamber and oriented such that respective facing directions of the nozzles substantially intersect at an impingement point.

[0009] A second aspect of the present disclosure includes a fluidic device comprising: a reactant passage configured to convey at least two reactants through the fluidic device, the reactant passage comprising at least three mixing units configured, respectively, according to the first aspect, the at least three mixing units arranged successively with the segment outlet ofSP24-273 a preceding mixing unit adjoining the segment inlet of a succeeding mixing unit such that the reactant passage segments of each mixing unit are fluidically connected and define a portion of the reactant passage.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various exemplary embodiments of the present disclosure are described in detail below with reference to the following drawings. The drawings are provided for purposes of illustration only and merely depict exemplary embodiments of the present disclosure to facilitate the understanding of the present disclosure. Therefore, the drawings should not be considered as limiting of the breadth, scope, or applicability of the present disclosure. It should be noted that for clarity and ease of illustration these drawings are not necessarily drawn to scale.

[0011] FIG. 1 is a top perspective view of a fluidic device comprising a reactant passage for continuous flow reactions according to embodiments of the present disclosure;

[0012] FIG. 2 is a block diagram of an embodiment of the reactant passage of FIG. 1 ;

[0013] FIG. 3 is a top view of the fluidic device of FIG. 1 with a top surface portion removed to show the reactant passage comprising a plurality of mixing units;

[0014] FIG. 4 is a top section view of a portion of the reactant passage comprising an inlet structure and a group of three mixing units;

[0015] FIG. 5 is an enlarged view of a (single) mixing unit of the series of three mixing units of FIG. 4 according to an embodiment of the present disclosure;

[0016] FIG. 6 is an enlarged view of a (single) mixing unit of the series of three mixing units of FIG. 4 according to another embodiment of the present disclosure;

[0017] FIG. 7 is a perspective view of a reactant passage segment of the mixing unit of FIG. 6 with a mixing portion on an upstream end and a retention portion on a downstream end;

[0018] FIG. 8 is an enlarged view of the mixing portion of the mixing unit of FIG. 7 with surfaces thereof shown partially transparent to illustrate details of the mixing portion;

[0019] FIGS. 9-11 comprise pairs of views (a perspective view and a side view) that illustrate embodiments of a mixing chamber of the mixing portion of the respective mixing units;SP24-273

[0020] FIGS. 12 and 13 are perspective views that illustrate embodiments of the retention portion of the reactant passage segment;

[0021] FIGS. 14-16 comprise pairs of views (a perspective view and a side view) that illustrate embodiments of mixing units used in a simulation to assess performance attributes associated with mixing of miscible fluids according to Example 1;

[0022] FIG. 17 is a top view of a portion of a mixing unit used in a simulation to illustrate mixing of immiscible fluids according to Example 2;

[0023] FIG. 18 is a top view of a portion of a reactant passage comprising an inlet structure and a group of three mixing units according to embodiments of the present disclosure;

[0024] FIG. 19 is an enlarged view of a retention portion fluidically connected to two mixing units according to embodiments of the present disclosure;

[0025] FIG. 20 is a top section view of a portion of a reactant passage comprising a group of four mixing units each of which comprises only the mixing portion;

[0026] FIG. 21 is a top section view of a portion of a reactant passage comprising a group of four mixing units some of which comprise only the mixing portion and one of which comprises both the mixing portion and the retention portion;

[0027] FIG. 22 is a perspective view of a portion of a reactant passage according to a prior art flow reactor;

[0028] FIG. 23 is a perspective view of an individual chamber of the prior art reactant passage of FIG. 22; and

[0029] FIG. 24 is a cross section of the individual chamber of FIG. 23.DETAILED DESCRIPTION

[0030] For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the disclosure is thereby intended. It is further understood that the present disclosure includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles disclosed herein as would normally occur to one skilled in the art to which this disclosure pertains.SP24-273

[0031] As used herein, the term “and / or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0032] In this document, relational terms, such as first and second, top and bottom, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0033] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term “about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not a numerical value or end-point of a range in the specification recites “about,” the numerical value or end-point of a range is intended to include two embodiments: one modified by “about,” and one not modified by “about.” It will be further understood that the end-points of each of the ranges are significant both in relation to the other end-point, and independently of the other end-point.

[0034] Concentrations, amounts, and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range was explicitly recited. As an illustration, a numerical range of “about 1 to about 5” should be interpreted to include not only the explicitly recited values of about 1 to about 5, but also to include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as 2, 3, and 4, the sub ranges such as from 1-3, from 2-4, from 3-5, etc., as well as 1, 2, 3, 4, and 5 individually. The same principle applies to ranges reciting only one numerical value as a minimum or maximum. Furthermore,SP24-273 such an interpretation should apply regardless of the breadth of the range or the characteristics being described by the range.

[0035] The terms “substantial,” “substantially,” and variations thereof as used herein, unless defined elsewhere in association with specific terms or phrases, are intended to note that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, “substantially” is intended to denote that two values are equal or approximately equal. In some embodiments, “substantially” may denote values within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

[0036] Directional terms as used herein — for example up, down, right, left, front, back, top, bottom, above, below, and the like — are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0037] As used herein the terms "the," "a," or "an," mean "at least one," and should not be limited to "only one" unless explicitly indicated to the contrary. Thus, for example, reference to "a component" includes embodiments having two or more such components unless the context clearly indicates otherwise.

[0038] FIGS. 1-3 depict a fluidic device 100 according to embodiments of the present disclosure. As used herein, “fluidic device” includes fluidic devices over a scale ranging from microns (e.g., microfluidic devices) to a few millimeters (e.g., milli-fluidic devices), that is, devices with fluid channels the smallest dimension of which is in the range of microns to a few millimeters, and preferably in the range of from about 10's of microns to about 1.5 millimeters. The fluidic device 100 comprises a body 104 and a fluid path 108 arranged in the body 104. The fluid path 108 comprises a reactant passage P that extends through the body 104 and a plurality of fluid structures disposed along the reactant passage P in fluid communication with one another and the reactant passage P. The fluid structures include an inlet 112 disposed at a first end of the reactant passage P and an outlet 1 16 disposed at a second end of the reactant passage P spaced from the first end. In embodiments, the inlet 112 is configured to receive reactants and convey the reactants to the reactant passage P and / or further fluid structures. In embodiments, the inlet 112 is configured to receive at least two reactants introduced, respectively, through separate sub-inlets. The inlet 112 in such embodiments is further configured to (separately) convey the at least two reactants for a portion of the inlet 112 and then to recombine the at least two reactants for delivery to the reactant passage P.SP24-273

[0039] The fluidic device 100 is configured (e.g., via the fluid path 108) to mix and convey the reactants along the reactant passage P in a flow direction F from the inlet 112 to the outlet 116 as indicated by arrow F. To facilitate the mixing functionality of the fluidic device 100, the fluid structures further include at least one mixing unit 120 disposed intermediate the inlet 112 and the outlet 116 along the reactant passage P. The fluid path 108 in embodiments can include further fluid structures, such as residence time channels, separation units, and / or interfaces for in-line analysis. The fluid structures can be disposed adjacent to one another along the fluid path 108 or spaced from one another along the fluid path 108 while fluidically connected via one or more segments of the reactant passage P.

[0040] In embodiments, the at least one mixing unit 120 includes a plurality of mixing units 120 in various configurations and / or multiple positions along the reactant passage P. In embodiments, some or all of the mixing units 120 can be arranged in one or more groups 124 of mixing units 120. For example, as schematically depicted in the block diagram of FIG. 2, the mixing units 120 in embodiments can include a first group 124a of mixing units 120, a second group 124b of mixing units 120, and a third group 124c of mixing units 120 spaced from one another and successively positioned between the inlet 112 and the outlet 116. The mixing units 120 within each group 124a, 124b, 124c can be arranged in parallel and / or serially with respect to each other.

[0041] Referring now to FIG. 3, a top view of the fluidic device 100 of FIG. 1 is shown with a top portion of the body 104 removed to show the reactant passage P comprising the mixing units 120 arranged in a plurality of groups 124 according to embodiments of the present disclosure. In the embodiment depicted in FIG. 3, the mixing units 120 within each group 124 are arranged serially (e.g., successively) with respect to each other, and the groups 124 of mixing units 120 are connected via sections of the reactant passage P. The various sections of the reactant passage P that connect the adjacent groups 124 of mixing units 120 can be straight sections, curved sections (as shown in FIG. 3), and / or sections that comprise both straight and curved portions.

[0042] In the embodiment depicted in FIG. 3, the fluidic device 100 includes twenty-two groups 124 of mixing units 120. A first group 124a of mixing units is disposed at an upstream end of the reactant passage P proximate the inlet 112. The first group 124a of mixing units comprises a first mixing unit 120ai (directly) connected to the inlet 112, a second mixing unit 120a2 (directly) connected to the first mixing unit 120ai, a third mixing unit 120a3 (directly) connected to the second mixing unit 120a2, and a fourth mixing unit 120a4 (directly) connectedSP24-273 to the third mixing unit 120a3. The fourth mixing unit 120a4 of the first group 124a is also connected to a curved section of the reactant passage P, which in turn is connected to another group 124 of the mixing units 120.

[0043] Referring still to FIG. 3, a second group 124b of mixing units is disposed at a downstream end of the reactant passage P proximate the outlet 116. The second group 124b of mixing units comprises a first mixing unit 120bi (directly) connected a curved section of the reactant passage P, a second mixing unit 120b2 (directly) connected to the first mixing unit 120bi, a third mixing unit 120b3 (directly) connected to the second mixing unit 120b2, a fourth mixing unit 120b4 (directly) connected to the third mixing unit 120b3, a fifth mixing unit 120bs (directly) connected to the fourth mixing unit 120b4, and a sixth mixing unit 120be (directly) connected to the fifth mixing unit 120bs. The sixth mixing unit 120be of the second group 124b is also connected to the outlet 116.

[0044] Referring still to FIG. 3, twenty additional groups 124 of mixing units are disposed successively between the first group 124a of mixing units and the second group 124b of mixing units. The fluidic device 100 in other embodiments can include fewer or greater numbers of groups 124 of mixing units. The groups 124 shown in FIG. 3 have from 3 to 6 mixing units 120 per group though in other embodiments the groups 124 can have fewer or greater numbers of mixing units 120 per group, such as from 2 to 10 mixing units per group or from 1 to 20 mixing units per group. Each “group” of mixing units can be referred to interchangeably as a “portion” of the reactant passage P. The inlet 112 and the mixing units 120 are described in more detail later in this disclosure.

[0045] The body 104 of the fluidic device 100 can have various shapes. In embodiments, such as depicted in FIGS. 1 and 3, the body 104 has a plate-like shape with atop surface 128, a bottom surface 132 opposed to the top surface 128, and an edge 136 connecting the top surface 128 and the bottom surface 132 along respective peripheries thereof. The top surface 128 and the bottom surface 132 in embodiments are substantially planar. The body 104 in embodiments can be a unified body that comprises separate components bonded to one another at a joint, such as at a joining plane. For example, as shown in FIG. 1, the body 104 can include a first or top body portion 140 and a second or bottom body portion 144 bonded to the top body portion 140 at a joining plane 148. The body 104 in embodiments can be a monolithic body such that the body is free of separate components (e.g., halves of the body) bonded to one another at a joint (observable and / or detectible), such as at a joining plane. In embodiments,SP24-273 the reactant passage P can be a tortuous fluid passage that extends through the unified body or the monolithic body.

[0046] The body 104 of the fluidic device 100 can be formed from a material that comprises one or more of ceramic, metal, polymer, glass, and glass ceramic. In embodiments in which the material of the body 104 is metal, the metal material can include stainless steels, such as 316L stainless steel and Hastelloy®, and other metals. In embodiments in which the material of the body 104 is a polymer, the polymer material can include fluorinated polymers, such as polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), and perfluoroalkoxy alkane (PF A), and other polymers, such as cyclic olefin polymer (COP), polystyrene (PS), and others. In embodiments in which the material of the body 104 is ceramic, the ceramic material can include oxide ceramics, non-oxide ceramics, glass-ceramics, and other ceramics that enable high density, closed-porosity structures or bodies.

[0047] Oxide ceramics are inorganic compounds of metallic (e.g., Al, Zr, Ti, Mg) or metalloid (Si) elements with oxygen. Oxides can be combined with nitrogen or carbon to form more complex oxynitride or oxycarbide ceramics. Non-oxide ceramics are inorganic, non- metallic materials and include carbides, nitrides, borides, silicides, and others. Some examples of non-oxide ceramics that can be used for the body 104 include boron carbide (B4C), boron nitride (BN), tungsten carbide (WC), titanium diboride (TiB2), zirconium diboride (ZrB2), molybdenum disilicide (MoSi2), silicon carbide (SiC), and silicon nitride (Si3N4). As used herein, a "closed-porosity" ceramic body is a ceramic body in which the ceramic material of the ceramic body exhibits a pore topology that is closed such that the pores or cells in the material are isolated or connected only with adjacent pores or cells and have no permeability to fluid.

[0048] In embodiments in which the material of the body 104 is ceramic, the ceramic material can include any pressable powder that is held together by a binder and thermally processed to fuse the powder particles together into the body. The body 104 in an exemplary embodiment is formed from SiC. In such an embodiment, the pressable powder can comprise a ready-to-press (RTP) SiC powder that includes binder(s) and / or other additives mixed with or coated thereon to facilitate pressing. Examples of such RTP SiC powder include SICS-18 from GNPGraystar of Buffalo, NY, United States; IKH 601 and 604 from Industriekeramik Hochrhein (IKH) GmbH of Wutoschingen, Germany; and StarCeram S alpha-SiC types SQ and RQ from KYOCERA Fineceramics Precision GmbH of Selb, Germany.SP24-273

[0049] Further aspects of the at least one mixing unit 120 are now described with reference to FIGS. 4-13. The “at least one mixing unit” may be referred to hereinafter as “the mixing unit” for ease of description. In embodiments, the mixing units 120 of a given fluidic device 100 can be identical or the mixing units 120 can be different, for example, in terms of overall size and / or size of certain features thereof. The mixing unit 120 comprises a reactant passage segment Psextending substantially along a first axis 152 (FIGS. 5 and 6) within a portion of the body 104 of the fluidic device 100. The first axis 152 corresponds to a theoretical line passing through the centroid of sequential cross sections of the reactant passage segment Psin the flow direction along an entire length of the mixing unit 120. While the first axis 152 is depicted as a straight line in the embodiments shown herein, it should be appreciated that the first axis 152 in other embodiments can include curved portions within a single plane (e.g., two-dimensional (2D) or plane curves) and / or curved portions that are not confined to a single plane (e.g., three-dimensional (3D) or space curves). The reactant passage segment Psof each mixing unit 120 defines a portion of the reaction passage P of the fluidic device 100.

[0050] The first axis 152 is intended to represent the general direction along which a given mixing unit 120 extends through the fluidic device 100. It should be appreciated that each mixing unit 120 can have its own first axis 152 or groups 124 of mixing units 120 (such as described above) can share a common first axis 152. If the mixing units 120 are arranged in parallel within a group 124 or if there are multiple parallel groups 124 of mixing units 120 with serially arranged mixing units 120 within each group (e.g., defining multiple flow paths through the fluidic device 100), then there will be multiple parallel axes 152 extending through the fluidic device 100. In embodiments, the first axis 152 lies substantially in a single plane interchangeably referred to as an axis plane 154 (FIGS. 9-11). The axis plane 154 in embodiments is substantially parallel to the top surface 128 and the bottom surface 132 of the body 104. The axis plane 154 in embodiments corresponds to a midplane of the body 104 positioned at approximately one-half the orthogonal distance between the top surface 128 and the bottom surface 132. The axis plane 154 in embodiments can correspond to the joining plane 148 when the body 104 of the fluidic device 100 is configured as a unified body, such as described above with reference to FIG. 1.

[0051] FIG. 4 is top section view of a portion of the reactant passage P taken along the axis plane 154 through the body 104 of an exemplary fluidic device 100 according to embodiments of the present disclosure. The portion of the reactant passage P shown in FIG. 4 comprises an inlet 112 and a group 124 of three mixing units 120. Dashed boxes are used in FIG. 4 toSP24-273 schematically illustrate that the inlet 112 and the mixing units 120 are formed by respective portions of the body 104, which define the interior surfaces of the inlet 112 and the mixing units 120. FIG. 5 is an enlarged view of a (single) mixing unit 120 of the group 124 of three mixing units 120 of FIG. 4 according to an embodiment of the present disclosure. FIG. 6 is an enlarged view of a (single) mixing unit 120 of the group 124 of three mixing units of FIG. 4 according to another embodiment of the present disclosure.

[0052] The inlet 112 comprises a plurality of sub-inlets such as a first inlet portion 113 and a second inlet portion 114 as shown in FIG. 4. The first inlet portion 113 and the second inlet portion 114 are configured to receive a first reactant and a second reactant, respectively, and maintain separation between the first and second reactants therein for at least a portion of flow through the inlet 112 in the flow direction F. In embodiments, the number of sub-inlets can be greater than 2, for example, 3 sub-inlets, or 4 sub-inlets, or 5 sub-inlets, each configured to receive a respective reactant and maintain separation of that respective reactant from other reactants introduced via other sub-inlets for at least a portion of flow through the inlet 112. The inlet 112 also comprises an outlet portion 115 through which the first reactant and the second reactant exit the inlet 112 into the fluid passage P. In embodiments, the fluids introduced via the sub-inlets are combined prior to exit through the outlet portion 115 as shown in FIG. 4.

[0053] Referring now to FIGS. 4-6, the reactant passage segment Psof each mixing unit 120 comprises a segment inlet 156 and a segment outlet 160 disposed downstream from the segment inlet 156 in the flow direction F of the reactant passage segment Ps. The reactant passage segment Psfurther comprises a mixing portion 164 that adjoins the segment inlet 156 and a retention portion 168 that is fluidically connected to the mixing portion 164 and adjoins the segment outlet 160. As described in more detail later in this disclosure, the mixing portion 164 is configured to mix the reactants with a high level of mixing uniformity, and the retention portion 168 is configured to provide the highly -mixed reactants sufficient residence time for the chemical reactions to take place before flowing to the next mixing unit 120. The retention portion 168 is further configured to provide a heat management / control function for the mixing unit 120, as described later in this disclosure.

[0054] Further aspects of the reactant passage segment Psof the mixing unit 120 are described with reference again to FIGS. 4-6 and additionally with reference to FIGS. 7 and 8. FIG. 7 is a perspective view of the reactant passage segment Psof the mixing unit 120 of FIG. 6 with the mixing portion 164 disposed generally on an upstream end of the reactant passage segment Psand the retention portion 168 disposed generally on a downstream end of theSP24-273 reactant passage segment Ps. FIG. 8 is an enlarged view of the mixing portion 164 of the mixing unit 120 of FIG. 7 with interior surfaces thereof shown partially transparent to illustrate details of the mixing portion 164.

[0055] The mixing portion 164 comprises a wall structure 172 configured to split the reactant passage segment Psinto at least two sub-passages 176. A central axis 180 of one of the at least two sub-passages 176 and a series of arrows along the central axis 180 (e.g., generally indicating the flow direction therethrough) are depicted in each of FIGS. 5 and 6. The central axis 180 corresponds to a theoretical line passing through the centroid of sequential cross sections of the sub-passage 176 in the flow direction through the sub-passage 176. The wall structure 172 at an upstream side thereof comprises a tapering elongated end 184 pointing in an upstream direction.

[0056] The mixing portion 164 further comprises a mixing chamber 188 into which each of the at least two sub-passages 176 opens through a nozzle 192. The nozzles 192 are spaced apart about the mixing chamber 188 (e.g., about a periphery of the mixing chamber 188) and oriented such that respective facing directions 196 of the nozzles 192 substantially intersect at an impingement point 200. With the nozzles 192 oriented such that the corresponding facing directions 196 substantially intersect, the two sub-streams of reactants that are flowed along the at least two sub-passages 176 and into the mixing chamber 188 (e.g., through the nozzles 192) collide into each for enhanced mixing during operation of the fluidic device 100. This mixing strategy is unlike conventional micromixers that employ the Split-And-Recombine (SAR) principle in which the recombined fluids / reactants collide into an obstacle to enhance the mixing. One advantage of using colliding sub-streams for mixing compared to SAR with obstacle(s) for mixing is a reduction in the energy loss of the reactants since there is less fluidwall interaction when using colliding sub-streams for mixing.

[0057] Referring now to FIGS. 5-7, the mixing chamber 188 has a plurality of interior chamber surfaces 204 that define a chamber volume 208 of the mixing chamber 188. The nozzles 192 and the mixing chamber 188 are configured to position and / or orient the facing directions 196 of the nozzles 192 such that the impingement point 200 (e.g., the intersection of the facing directions 196) is disposed within the chamber volume 208. The interior chamber surfaces 204 ofthe mixing chamber 188 comprise atop chamber surface 216, a bottom chamber surface 220 spaced from the top chamber surface 216, and a peripheral chamber surface 224 that extends between the top chamber surface 216 and the bottom chamber surface 220 substantially along a second axis 228 (FIGS. 9-11) oriented normal to the first axis 152 and / orSP24-273 the axis plane 154. In embodiments, the peripheral chamber surface 224 is arcuate and at least partially encircles the second axis 228. In an exemplary embodiment, as best shown in FIGS. 5 and 6, the wall structure 172 has a concave surface 232 that faces in the downstream direction and defines a portion of the peripheral chamber surface 224 of the mixing chamber 188.

[0058] As best shown in FIG. 8, the mixing chamber 188 has a chamber height hmextending between the top chamber surface 216 and the bottom chamber surface 220 along the second axis 228 (FIGS. 9-11). Each nozzle 192 has a nozzle profile 236 defined at an intersection of the respective sub-passage 176 and the mixing chamber 188 (e.g., the peripheral chamber surface 224 of the mixing chamber 188). The nozzle profile 236 comprises a nozzle height h„ that is parallel to the second axis 228 and a nozzle width wnthat is substantially orthogonal to the nozzle height hn. In embodiments, the nozzle height hnof the nozzle profile 236 is less than the chamber height hmof the mixing chamber 188. In embodiments, an upstream-most portion of the nozzle profile 236 has a nonzero offset distance (t / «) in the downstream direction from an upstream-most portion of the peripheral chamber surface 224 of the mixing chamber (188). In the embodiment shown in FIG. 8, the upstream-most portion of the nozzle profile 236 is an upstream edge of the nozzle profile 236.

[0059] Referring now to FIGS. 6-8, the retention portion 168 of the reactant passage segment Psfurther comprises a transition section 240 through which the retention portion 168 is fluidically connected to the mixing chamber 188. The mixing chamber 188 has a chamber opening 244 through which the transition section 240 opens into the chamber volume 208. As best shown in FIG. 8, the chamber opening 244 is disposed downstream from the nozzles 192 and extends through the peripheral chamber surface 224 of the mixing chamber 188.

[0060] The transition section 240 has a cross section 246 oriented normal to the direction in which the retention portion 168 extends from the mixing chamber 188 to the segment outlet 160 (e.g., oriented normal to the first axis 152). In an exemplary embodiment, the cross section 246 of the transition section 240 has a rectangular shape, such as shown in FIG. 8. The cross section 246 in other embodiments can have different shapes, such as circular, stadium, trapezoidal, or others. In embodiments, the transition section 240 has a top transition surface 248, a bottom transition surface 252 spaced from the top transition surface 248, and opposed side transition surfaces 256 that extend between the top transition surface 248 and the bottom transition surface 252 and are substantially parallel to the second axis 228. In embodiments, the opposed side transition surfaces 256 expand outwardly (e.g., away from the first axis 152) in the downstream direction from the chamber opening 244 of the mixing chamber 188.SP24-273

[0061] As best shown in FIG. 8, the transition section 240 has a transition section height htthat is substantially parallel to the second axis 228. In an exemplary embodiment, the transition section height htextends between the top transition surface 248 and the bottom transition surface 252. In embodiments, the transition section height ht can be an average height, a maximum height, or a minimum height between opposed surfaces (e.g., top and bottom surfaces 248, 252) or opposed portions of a surface In embodiments, the chamber height hmof the mixing chamber 188 is equal to or greater than the transition section height htof the transition section 240. The nozzle height hnof the nozzle profile 236 can be less than or equal to the transition section height htof the transition section 240. The nozzle height hnin an exemplary embodiment is less than the transition section height ht.

[0062] Referring again to FIGS. 6-8, the retention portion 168 has a cross section 258 oriented normal to the direction in which the retention portion 168 extends from the mixing chamber 188 to the segment outlet 160 (e.g., oriented normal to the first axis 152). In an exemplary embodiment, the cross section 258 of the retention portion 168 has a rectangular shape, such as shown in FIG. 7. The cross section 258 in other embodiments can have different shapes, such as circular, stadium, trapezoidal, or others. In embodiments, the retention portion 168 has a top retention surface 260, a bottom retention surface 264 spaced from the top retention surface 260, and opposed side retention surfaces 268 that extend between the top retention surface 260 and the bottom retention surface 264 and are substantially parallel to the second axis 228. In embodiments, the top retention surface 260 and the bottom retention surface 264 of the retention portion 168 are planar and oriented substantially parallel to one another. In embodiments, the opposed side retention surfaces 268 are planar and oriented substantially parallel to one another. In embodiments, the opposed side transition surfaces 256 of the transition section 240 are configured to taper the opposed side retention surfaces 268 so as to match the chamber opening 244.

[0063] In embodiments, the cross section 246 of the transition section 240 and the cross section 258 of the retention portion 168 match (e.g., correspond in size and shape) at a transition region 272. In embodiments, the transition region 272 corresponds generally to the position along the first axis 152 at which the outwardly-expanding opposed side transition surfaces 256 of the transition section 240 intersect the substantially parallel opposed side retention surfaces 268 of the retention portion 168.

[0064] As best shown in FIG. 7, the retention portion 168 has a retention portion height hrthat extends between the top retention surface 260 and the bottom retention surface 264 and isSP24-273 substantially parallel to the second axis 228. In embodiments, the retention portion height hrof the retention portion 168 and the transition section height htof the transition section 240 are approximately equal. Referring still to FIG. 7, in embodiments, the retention portion 168 has a retention portion length lralong the first axis 152 that is approximately equal to or greater than a mixing portion length lmof the mixing portion 164 along the first axis 152. Alternatively, in embodiments, the mixing portion length lmis greater than the retention portion length lr.

[0065] As shown in FIG. 7, the retention portion length lrand the mixing portion length lmare both measured with reference to a reference line RL that defines a minimum offset for the retention portion 168 downstream from the impingement point 200. In embodiments, the minimum offset is greater than the distance between the nozzle 192 and the impingement point 200 along the facing direction 196. In embodiments, the retention portion length lr(e.g., the distance between the reference line RL and the segment outlet 160) can equal 25 times, 50 times, 75 times, 100 times, or more of a width wr-o of the retention portion 168 at the segment outlet 160.

[0066] Referring now to FIGS. 6 and 7, the segment inlet 156 can be located with reference to a tip of the tapering elongated end 184 of the wall structure 172. For example, as shown in FIG. 6, the segment inlet 156 can be positioned a first distance di from the tip of the wall structure 172. In embodiments, the first distance di can be from 0 to 500% of the half the width wm-i of the mixing portion 164 at the segment inlet 156, such as from 0 to 150% of the half the width wm-i or from 0 to 50% of half the width wm-i.

[0067] Referring again to FIG. 7, the reactant passage segment Psof the mixing unit 120 has a volume ratio between a retention volume of the retention portion 168 (e.g., solid grayscale fill) and a mixing volume of the mixing portion 164 (e.g., checkered surface hatching). In embodiments, the volume ratio is configurable to maximize mixing uniformity and minimize pressure drop. In such embodiments, the volume ratio can be set in a range of from about 1: 1 to about 15: 1. In some embodiments, as discussed later in this disclosure with reference to FIGS. 20 and 21, the retention portion 168 can be omitted from the mixing unit 120 in which case the volume ratio between the retention volume and the mixing volume is zero (e.g., zero retention volume if no retention portion).

[0068] Further aspects of the at least two sub-passages 176 and the mixing chamber 188 of the mixing portion 164 are now described with reference again to FIGS. 5 and 6. In embodiments, a shape of the peripheral chamber surface 224 of the mixing chamber 188 canSP24-273 differ. For example, as shown in FIG. 5, the peripheral chamber surface 224 has a cross- sectional shape that approximates a stadium (e.g., a rectangle with semicircles substituted at opposite ends thereof) when viewed in a plane normal to the second axis 228, such as the axis plane 154 (FIGS. 9-11). As shown in FIG. 6, the peripheral chamber surface 224, when viewed in the axis plane 154, has a cross-sectional shape that approximates a circle such that the respective shapes of the peripheral chamber surfaces 224 of the mixing chambers 188 of FIGS. 5 and 6 differ from one another.

[0069] In each of FIGS. 5 and 6, aportion 276 of the cross-sectional shape ofthe peripheral chamber surface 224 of the mixing chamber 188 is shown using dashed line-type to illustrate that the peripheral chamber surface 224 is not physically present at the indicated location in the axis plane 154 (e.g., due to the location of the chamber opening 244), but the peripheral chamber surface 224 is physically present at the indicated location in other (parallel) planes along the second axis 228. For example, the circular cross-sectional shape of the peripheral chamber surface 224 of FIG. 6 includes a circular portion 276 depicted in dashed line-type. In FIGS. 7 and 8, this same circular portion corresponds to portions of the peripheral chamber surface 224 that are physically present in parallel planes above and below the section plane (e.g., the axis plane 154) of FIG. 6.

[0070] In embodiments, a path ofthe central axis 180 ofthe at least two sub-passages 176 in the flow direction F can differ. As shown in FIGS. 5 and 6, each of the at least two subpassages 176 has a first sub-passage segment 181 (e.g., along the central axis 180) that is disposed along an upstream portion of the sub-passage 176 and extends gradually away from the first axis 152 in the downstream direction. Each of the at least two sub-passages 176 also has a second sub-passage segment 182 (e.g., along the central axis 180) that is connected to the first sub-passage segment 181 and extends abruptly towards the first axis 152 in the downstream direction.

[0071] As can be seen by comparing FIGS. 5 and 6, the curved transition of the path of the central axis 180 from the first sub-passage segment 181 to the second sub-passage segment 182 along each of the sub-passages 176 of FIG. 6 has a smaller radius of curvature compared to the same curved transition of the path of the central axis 180 along each of the sub-passages 176 of FIG. 5. Because of this difference in the respective curved transitions, the nozzles 192 can be positioned and / or oriented differently about the periphery of the mixing chamber 188, which in turn can orient the facing directions 196 of the nozzles 192 differently.SP24-273

[0072] As can be seen by comparing FIGS. 5 and 6, an angle a on an upstream side of the impingement point 200 between the facing directions 196 of the nozzles 192 of FIG. 6 is greater than the same angle a between the facing directions 196 of the nozzles 192 of FIG. 5. Because of this difference in the respective angles a of the facing directions 196, the impingement point 200 can be positioned differently within the chamber volume 208 of the mixing chamber 188. In embodiments, the angle a can be in a range from about 180° to about 270°, such as from about 180° to about 260°, from about 180° to about 250°, from about 180° to about 240°, from about 180° to about 230°, from about 170° to about 270°, or from about 190° to about 270°, and also comprising all sub-ranges and sub-values between these range endpoints. In embodiments, depending on the angle a, the facing directions 196 can be parallel (e.g., when the angle a is 180°), or the facing directions 196 can be transverse (e.g., when the angle is greater than 180°).

[0073] Referring again to FIGS. 4-13, one or more of the retention portion 168, the wall structure 172, the at least two sub-passages 176, and the mixing chamber 188 are symmetric about a symmetry plane of the mixing unit 120. In embodiments, the symmetry plane is defined by the first axis 152 and the second axis 228.

[0074] Referring now to FIGS. 9-11, respective pairs of views (a perspective view and a side view for each figure) are used to illustrate further aspects of the mixing chamber 188 of the reactant passage segment Psthat are made possible when the chamber height hmof the mixing chamber 188 is greater than the transition section height htof the transition section 240. Some of these further aspect may improve the manufacturability of the mixing units 120 whereas others of these further aspects may additionally or alternatively improve performance (e.g., increase mixing uniformity and / or reduce pressure drop) of the mixing units 120.

[0075] In the embodiments shown in FIGS. 9 and 10, the top chamber surface 216 and the bottom chamber surface 220 of the mixing chamber 188 are planar and oriented substantially parallel to one another. In the embodiment shown in FIG. 9, respective intersections of the top chamber surface 216 and the bottom chamber surface 220 with the peripheral chamber surface 224 terminate at a relatively sharp edge. Similarly, respective intersections of the top transition surface 248 and the bottom transition surface 252 with the peripheral chamber surface 224 terminate at a relative sharp edge . In contrast, in the embodiment shown in FIG. 10, respective intersections of the top chamber surface 216 and the bottom chamber surface 220 with the peripheral chamber surface 224 terminate at an edge with a fillet (e.g., a rounded edge).SP24-273Similarly, respective intersections of the top transition surface 248 and the bottom transition surface 252 with the peripheral chamber surface 224 terminate at an edge with a fillet.

[0076] In embodiments, such as shown in FIG. 11, one or more of the top chamber surface 216 and the bottom chamber surface 220 of the mixing chamber 188 has a hemispherical bulge 280 that is outwardly extending with respect to chamber volume 208. In the exemplary embodiment shown in FIG. 11, the top chamber surface 216 and the bottom chamber surface 220 of the mixing chamber 118 have opposing hemispherical bulges 280 that are outwardly extending with respect to chamber volume 208. In embodiments that include the hemispherical bulge 280, a portion of the top transition surface 248 and / or a portion of the bottom transition surface 252 disposed proximate the hemispherical bulge 280 can have a corresponding bulging portion 282 that is outwardly extending and tapers the hemispherical bulge 280 into a remaining portion of the corresponding transition surface of the transition section 240 (e.g., a remaining portion of the corresponding transition surface that is planar). The embodiments of the mixing portion 164 depicted in FIGS. 9-11 are generally ordered with increasing complexity from the manufacturing point of view (e.g., FIG. 9 as least complex and FIG. 11 as most complex).

[0077] The shape of the interior chamber surfaces 204 of the mixing chamber 188 (e.g., the top chamber surface 216, the bottom chamber surface 220, and the peripheral chamber surface 224) relative to the impingement point 200 as well as the three-dimensional spacing of the interior chamber surfaces 204 from the impingement point 200 (e.g., the free space) are important parameters used to achieve the exceptional mixing uniformity from fluidic devices 100 that employ the mixing units 100 disclosed herein.

[0078] Referring still to FIGS. 9-11 and additionally to FIGS. 4-8, one or more of the at least two sub-passages 176 comprises a narrowing portion 183 along which successive cross sections of the sub-passage 176 in the downstream direction become successively smaller in terms of surface area until the sub-passage 176 adjoins the nozzle 192. In embodiments, each of the at least two sub-passages 176 comprises the narrowing portion 183. The narrowing of the narrowing portion 183 can include reducing one or more orthogonal dimensions (e.g., a height dimension and / or a width dimension) of the cross section of the sub-passage 176 at successive positions of the cross section in the downstream direction. For example, as best shown in FIGS. 5 and 6, a width of the sub-passages 176 (e.g., in a direction normal to the central axis 180) becomes increasingly smaller sequentially along each of the first sub-passage segment 181 and the second sub-passage segment 182 in the downstream direction.SP24-273

[0079] Similarly, as best shown in FIGS. 9-11, a height of the sub-passages 176 (e.g., in a direction parallel to the second axis 228) becomes increasingly smaller sequentially along at least the second sub-passage segment 182 in the downstream direction, especially proximate the intersection of the sub-passages 176 with mixing chamber 188. The narrowing of the narrowing portion 183 with respect to the height dimension can facilitate the relationship in which the nozzle height hnof the nozzle 192 is less than the transition section height htof the transition section 240. The narrowing portion 183 locally increases the flow of reactants through the sub-passages 176 and out of the nozzles 192 so as to form (high-speed) impinging jets of reactants that are directed towards the impingement point 200 within the mixing chamber 188. The nozzle 192 can be further characterized in connection with the narrowing portion 183. For example, the nozzle 192 can be associated with a narrowed portion of a flow path (e.g., the narrowing portion 183) that increases velocity of the flow and directs a stream of the flow into a less-constrained space, such as where the flow rate increases by at least 10%, such as at least 50%, such as at least 100%, such as at least 300% relative to a wider-, preceding- portion of the flow path.

[0080] The various features of the mixing chamber 188 disclosed herein individually and collectively contribute to achieving a high mixing uniformity of reactants flowed through the mixing unit 120. In the chemical reactor art, two cases of mixing are generally envisioned: (i) miscible fluids mixing and (ii) immiscible fluids mixing (e.g., gas / liquid mixing and immiscible liquids mixing). With regard to miscible fluids mixing, high-quality mixing correlates with the appearance of flow instabilities, such as vortex structures and / or turbulent vortexes. The instability provided by the collision of the two (high-speed) impinging jets within the mixing chamber 188 is advantageous for the formation of such vortexes. With regard to immiscible fluids mixing, high-quality mixing is related to the shear stresses generated in the mixing zone. The impinging jets formed within the mixing chamber 188, as disclosed herein, provide both unstable vortexes and high shear stress layers at the impingement point 200, thereby leading to favorable mixing behaviors. The formation of an optimized collision region (high shear stress layers with low stability) for impinging jets requires some free space for the colliding reactants to spread freely in three dimensions.

[0081] To facilitate providing such free space, the chamber volume 208 of the mixing chamber 188 in embodiments is configured to provide a minimum clearance about the impingement point 200. For example, one or more of (i) the shape of the interior chamber surfaces 204 ofthe mixing chamber 188 (e.g., the top chamber surface 216, the bottom chamberSP24-273 surface 220, and the peripheral chamber surface 224) relative to the impingement point 200 and (ii) the three-dimensional spacing of the interior chamber surfaces 204 from the impingement point 200 can be configured to define the minimum clearance about the impingement point 200. In embodiments, the minimum clearance is configured as a minimum spherical clearance that is centered at the impingement point 200. In embodiments, the minimum spherical clearance is at least 2 times the hydraulic diameter of one of the nozzles 192, such as 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.5, 4, 4.5, or 5 times the hydraulic diameter of one of the nozzles 192. The use of smaller dimensions for the nozzle 192 (e.g., a smaller nozzle height hnand a smaller nozzle width w„ for the nozzle profile 236) compared to the mixing chamber can also facilitate providing such free space.

[0082] Referring now to FIGS. 12 and 13, further aspects of the retention portion 168 are shown. In embodiments, the retention portion 168 can comprise a plurality of mixing structures 284 configured to maintain at least some mixing of the reactants after the flowing from the mixing portion 164. In embodiments, one or more of the mixing structures 284 extend between the top retention surface 260 and the bottom retention surface 264. In embodiments, additionally or alternatively, one or more of the mixing structures (not shown) extend partially between the top retention surface 260 and the bottom retention surface 264.

[0083] As shown in FIG. 12, the mixing structures 284 can be arranged in a sequence 288 of mixing structures 284 (e.g., one behind the other in a single line) in a direction substantially along the flow direction F. In embodiments, the size and / or the shape of the mixing units 284 in the sequence 288 are the same. In embodiments, at least two of the mixing structures 284 of the sequence 288 have different sizes (e.g., a width, diameter, and / or height) and / or different shapes when viewed in a plane (e.g., the axis plane 154) normal to the second axis 228, such as shown in FIG. 12. For example, a first mixing structure 284a at an upstream side of the retention portion 168 has a smaller diameter than a second mixing structure 284b disposed downstream from and adjacent to the first mixing structure 284a. Similarly, the second mixing structure 284b has a smaller diameter than a third mixing structure 284c disposed downstream from and adjacent to the second mixing structure 284b.

[0084] As shown in FIG. 13, the mixing structures 284 can be arranged in an array 292 of mixing structures 284 along the flow direction F. In embodiments, the size and / or the shape of the mixing units 284 in the array 292 are the same, such as shown in FIG. 13. In embodiments, at least two of the mixing structures 284 of the array 292 have different sizes (e.g., a width, diameter, and / or height) and / or different shapes when viewed in a plane (e.g., the axisSP24-273 plane 154) normal to the second axis 228. In embodiments, the retention portion 168 can include a first portion with mixing structures 284 arranged in the sequence 288 and a second portion with mixing structures 284 arranged in the array 292. The mixing structures 284 can have various configurations, such as pillars, fins, stubs, cones, etc.

[0085] After the reactants exit the mixing portion 164 of the mixing unit 120, the reactants pass through the retention portion 168 so that chemical reactions can take place immediately after the formation of a high level of mixing uniformity. For immiscible fluids mixing, it is also important to maintain good mixing quality since the two phases could separate again in the absence of sufficient continued mixing / agitation. The mixing structures 284 in the retention portion 168 can help maintain emulsification.EXAMPLES

[0086] Various embodiments of the present disclosure can be better understood by reference to the following Examples which are offered by way of illustration. The present disclosure is not limited to the Examples given herein.Example 1 - Mixing Uniformity under Miscible Fluids Mixing

[0087] The miscible fluids mixing was modeled using the fluid simulation software Ansys Fluent. The volume of each mixing unit 120 was scaled to be about 5 mb, which is a typical volume for large mixing units / cells in micro / milli-reactors, such as commercially available Coming® Advanced-Flow™ Reactors (AFR) industrial reactors. The basic geometry of the mixing units / cells of the AFR reactors (referred to hereinafter as “AFR ref’) is described above in the background section with reference to FIGS. 18-20. The mixing process of an acid mixture (H2SO4 + HNO3) and nitric acid was modeled in the simulation. These two fluids have different viscosities and densities. For the acid mixture, the viscosity was 0.07 kg / (m s) and the density was 1228 kg / m3. For the nitric acid, the viscosity was 0.001 kg / (m s) and the density was 1385 kg / m3. The flow rate ratio between the two fluids was set to be 0.35: 1. The total flowrate was set at 5 kg / min.

[0088] The mixing uniformity in the first three mixing units of a group of mixing unit (e.g., mixing units 120ai, 120a2, 120a3 of group 124a in FIG. 3) were compared for the three different embodiments illustrated in FIGS. 14-16. FIG. 14 depicts a fully two-dimensional (2D) design (“Design 1”) without variation between the nozzle height hnof the nozzle 192 and the transition section height htof the transition section 240. In Design 1, the peripheral chamber surface 224 of the mixing chamber 188 has a circular cross-sectional shape and extends between a planarSP24-273 top chamber surface 216 and a planar bottom chamber surface 220 such that the chamber volume 208 approximates a cylinder. As used herein, “2D design” refers to designs that exhibit a uniform channel height throughout the mixing unit and can be produced by simple 3 -axis machining.

[0089] FIG. 15 depicts a simple 2.5D design (“Design 2) also without variation between the nozzle height hnof the nozzle 192 and the transition section height ht of the transition section 240. In Design 2, the top chamber surface 216 and the bottom chamber surface of the mixing chamber 188 are configured with respective hemispherical (dome-shaped) bulges 280. The transition section 240 in Design 2 comprises a bulging portion 282 that tapers the hemispherical bulge 280 into a remaining (planar) portion of the transition section 240. As used herein, “2.5D design” or “simple 3D” refers to designs that exhibit variable channel height but can be produced by multistep 3-axis machining.

[0090] FIG. 16 depicts a more complex 2.5D design (“Design 3”) with variation between the nozzle height hnof the nozzle 192 and the transition section height htof the transition section 240 such that the nozzle height h„ is smaller than the transition section height ht. In Design 3, the top chamber surface 216 and the bottom chamber surface of the mixing chamber 188 are configured with respective hemispherical (dome-shaped) bulges 280. The transition section 240 in Design 3 comprises a bulging portion 282 that tapers the hemispherical bulge 280 into a remaining (planar) portion of the transition section 240.

[0091] Table 1 reports the results for mixing uniformity at the segment outlet 116 of each mixing unit 120 and the pressure drop modeled for the three mixing units 120 in each of Designs 1-3 and for three mixing units of the AFR ref reactor.

[0092] Table 1. Comparison of mixing uniformity and pressure drop in tested designs.Mixing Uniformity Design , , dP (bar)1stMixing Unit 2ndMixing Unit 3rdMixing UnitAFR ref 0.90 0.96 0.98 0.291 0.89 0.95 0.97 0.272 0.88 0.97 0.99 0.273 0.98 0.99 0.999 0.42

[0093] The mixing uniformity of Design 1 is almost the same as in the AFR ref model. The pressure drop of Design 1 is slightly smaller than the pressure drop in the AFR ref model. Design 3 shows the best mixing performance since it can achieve the same mixing uniformity in one mixing unit as can be achieved in three mixing units of the AFR ref model. The pressureSP24-273 drop of Design 3 is higher than the pressure drop in the AFR ref model, but such pressure drop in Design 3 could be balanced by a reduction in the number of mixing units.Example 2 -Mixing Visualization under Immiscible Fluids Mixing

[0094] The immiscible fluids mixing is very resource-consuming in terms of modeling. One example, shown in FIG. 17, has been realized using water as the continuous phase (transparent) and hexane as the dispersed phase (yellow). The small diameter of formed droplets indicates an efficient dispersion and a high quality of mixing.

[0095] The embodiments of the mixing units 120 disclosed herein as well as fluidic devices that incorporate said mixing units exhibit numerous advantages and benefits. The mixing units disclosed herein show high mixing effectiveness (uniformity). The volume ratio of the mixing portion and the retention portion of each mixing unit can be adjusted for an optimized pressure drop and mass transfer behavior. The mixing units disclosed herein have a more compact form compared to some existing configurations, such as the heart-shaped mixing units / cells of the AFR reactors. Such a compact form enables more compact packaging with a fluidic module and possibly higher internal volume for each fluidic module, leading to higher reactor productivity. The mixing units disclosed herein can be produced by the silicon carbide (SiC) machining and sealing process currently used for Coming AFR fluidic modules.

[0096] While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications, and further applications that come within the spirit of the disclosure are desired to be protected. For example, FIGS. 18-21 illustrate modifications that come within the spirit of the disclosure.

[0097] FIG. 18 is a top view of a portion of a reactant passage P comprising an inlet 112' and three mixing units 120', 120". FIG. 19 is a top view of a retention portion 168" fluidically (and directly) connected to two of the three mixing units. The configuration depicted in FIGS. 18 and 19 allows for parallelization of the mixing units 120', 120" so as to provide multiple flow paths through a fluidic device. As shown in FIG. 18, the inlet 112' comprises a first inlet portion 113 and a second inlet portion 114' (e.g., sub-inlets 113, 114') configured to receive a first reactant and a second reactant, respectively, and maintain separation between the first and second reactants therein for at least a portion of flow through the inlet 112' in the flow direction F. The inlet 112' also comprises an outlet portion 115' through which the first reactant and theSP24-273 second reactant exit the inlet 112' into the fluid passage P. In embodiments, the fluids introduced via the sub-inlets 113, 114' are combined prior to exiting through the outlet portion 115' as shown in FIG. 18.

[0098] The inlet 112' shown in FIG. 18 has differences compared to the inlet 112 discussed above with respect to FIG. 4. For example, the second inlet portion 114' of FIG. 18 splits into two sub-passages that separately combine with the two sub-passages of the first inlet portion 113 at respective outlet portions 115'. Thereafter, a first outlet portion 115' fluidically connects to one of the sub-passages 176' of a first mixing unit 120' and a second outlet portion 115' fluidically connects to the other of the sub-passage 176' of the first mixing unit 120'. The subpassages 176' of the first mixing unit 120' shown in FIG. 18 have differences compared to the sub-passages 176 discussed above with respect to FIGS. 4-16. In particular, the sub-passages 176' of FIG. 18 are separated over their entire extent whereas the sub-passages 176 of the mixing units 120 discussed hereinabove are connected to one another proximate the outlet portion 115, such as shown in FIG. 4. Once the reactants flow through the sub-passages 176' and arrive at the nozzles 192, the reactants are jetted into the mixing chamber 188 of the first mixing unit 120' and flow through the transition section and into the retention portion 168'.

[0099] The retention portion 168' of the first mixing unit 120' of FIG. 18 has differences compared to the retention portion 168 discussed above with respect to FIGS. 4-16. For example, the retention portion 168' of FIG. 18 is configured to branch into a first branched retention portion 168a' and a second branched retention portion 168b'. As shown in FIG. 18, the first branched retention portion 168a' fluidically connects to a second mixing unit 120a" and the second branched retention portion 168b' fluidically connects to a third mixing unit 120b". The second mixing unit 120a" and the third mixing unit 120b" have similar mixing portions 164a'', 164b'' (e.g., sub-passages 176, mixing chambers 188, and transition sections 240) as shown in FIG. 18. The second mixing unit 120a'' and the third mixing unit 120b" are configured to provide multiple flow paths through the fluidic device.

[0100] The retention portion 168" associated with the second mixing unit 120a" and the third mixing unit 120b" has differences compared to retention portion 168 discussed above with respect to FIGS. 4-16 and compared to the retention portion 168' discussed with respect to the first mixing unit 120' of FIG. 18. For example, as best shown in FIG. 19, the retention portion 168" is fluidically (and directly) connected to both the second mixing unit 120a" and the third mixing unit 120b" via respective transitions sections. In this configuration, reactantsSP24-273 exiting either one of the mixing chambers 188 of the second mixing unit 120a" and the third mixing unit 120b" can intermix along the (common) retention portion 168".

[0101] Referring still to FIG. 19, the retention portion 168a" comprises one or more heat exchange features 296 that can extend transversely from at least one of the top retention surface 260 and the bottom retention surface 264 (FIG. 7) and extend along the retention portion length lr. (FIG. 7). In embodiments, the one or more heat exchange features 296 can extend entirely between the top retention surface 260 and the bottom retention surface 264. In embodiments, the one or more heat exchange features 296 can extend partially between the top retention surface 260 and the bottom retention surface 264 from one or both of these surfaces. In embodiments, the one or more heat exchange features 296 extend for at least 50% of the retention portion length lr. In embodiments, the one or more heat exchange features 296 are configured as elongated fins. The elongated fins can extend through retention portion 168", as described herein. The elongated fins can also extend from the top retention surface 260 and / or the bottom retention surface 264 away from the retention portion 168" to increase the surface area of the retention portion 168". The one or more heat exchange features 296 can have any shape or structure that enables the features to provide a heat management / control function for the mixing unit.

[0102] FIGS. 20 and 21 are top section views of a portion of the reactant passage P similar to the top section view of FIG. 4 but showing alternative configurations of the mixing units 120. For example, FIG. 20 shows a configuration in which each of the mixing units 120'" comprises the mixing portion 164 but does not comprise retention portion 168. In this configuration, the mixing portions 164 are directly connected to one another in series along the portion of the reactant passage P. This configuration can be provided for the entire reactant passage P or portion thereof when continuation mixing / agitation is needed. FIG. 21 shows a configuration in which some of the mixing units 120'" comprise only the mixing portion 164, such as described in FIG. 20, and at least one of the mixing units 120 comprises both the mixing portion 164 and the retention portion 168 as described throughout the disclosure. In FIGS. 20 and 21, the mixing portion length lm(FIG. 7) and / or the retention portion length lr(FIG. 7), if present, can be varied from mixing unit to mixing unit, or for only certain groups of mixing unit, as needed, to provide customized mixing. .

Claims

SP24-273CLAIMSWhat is claimed is:1 . A mixing unit for a fluidic device, comprising: a reactant passage segment extending substantially along a first axis within a portion of the fluidic device, the reactant passage segment comprising a mixing portion that adjoins a segment inlet and a retention portion that is fluidically connected to the mixing portion and adjoins a segment outlet disposed downstream from the segment inlet in a flow direction of the reactant passage segment, the mixing portion comprising (i) a wall structure configured to split the reactant passage segment into at least two sub-passages and (ii) a mixing chamber into which each of the at least two sub-passages opens through a nozzle, the nozzles spaced apart about the mixing chamber and oriented such that respective facing directions of the nozzles substantially intersect at an impingement point.

2. The mixing unit of claim 1, wherein the mixing chamber has a plurality of interior chamber surfaces that define a chamber volume, the impingement point disposed within the chamber volume.

3. The mixing unit of claim 2, wherein the chamber volume is configured to provide a minimum spherical clearance about the impingement point, and wherein the minimum spherical clearance is at least 2 times a hydraulic diameter of one of the nozzles.

4. The mixing unit of claim 2 or claim 3, wherein the interior chamber surfaces of the mixing chamber comprise a top chamber surface, a bottom chamber surface spaced from the top chamber surface, and a peripheral chamber surface that extends between the top chamber surface and the bottom chamber surface substantially along a second axis that is normal to the first axis.

5. The mixing unit of claim 4, wherein the top chamber surface and the bottom chamber surface of the mixing chamber are planar and oriented substantially parallel to one another.

6. The mixing unit of claim 4, wherein one or more of the top chamber surface and the bottom chamber surface of the mixing chamber has a hemispherical bulge.SP24-2737. The mixing unit of claim 4, wherein the top chamber surface and the bottom chamber surface of the mixing chamber have opposing hemispherical bulges.

8. The mixing unit of any one of claims 4-7, wherein the peripheral chamber surface of the mixing chamber is arcuate and at least partially encircles the second axis.

9. The mixing unit of any one of claims 4-8, wherein the wall structure has a concave surface that faces in a downstream direction and defines a portion of the peripheral chamber surface of the mixing chamber.

10. The mixing unit of claim 4-9, wherein: the mixing chamber has a chamber height extending between the top chamber surface and the bottom chamber surface along the second axis, each nozzle has a nozzle profile defined at an intersection of the respective sub-passage and the mixing chamber, and the nozzle profile comprises a nozzle height that is parallel to the second axis and less than the chamber height of the mixing chamber.

11. The mixing unit of claim 10, wherein an upstream -most portion of the nozzle profile has a nonzero offset distance in the downstream direction from an upstream-most portion of the peripheral chamber surface of the mixing chamber.

12. The mixing unit of claim 10 or claim 11 , wherein the retention portion further comprises a transition section through which the retention portion is fluidically connected to the mixing chamber, the mixing chamber having a chamber opening through which the transition section opens into the chamber volume.

13. The mixing unit of claim 12, wherein the chamber opening is disposed downstream from the nozzles and extends through the peripheral chamber surface of the mixing chamber.

14. The mixing unit of claim 12 or claim 13, wherein the transition section has a transition section height that is parallel to the second axis, and wherein the chamber height of the mixing chamber is equal to or greater than the transition section height.SP24-27315. The mixing unit of claim 14, wherein the nozzle height of the nozzle profile is less than the transition section height of the transition section.

16. The mixing unit of claim 14 or claim 15, wherein the retention portion has a retention portion height that is substantially parallel to the second axis, and wherein the retention portion height and the transition section height are approximately equal.

17. The mixing unit of any one of claims 1-16, wherein the retention portion has a retention portion length along the first axis that is approximately equal to or greater than a mixing portion length of the mixing portion along the first axis.

18. The mixing unit of any one of claims 1-17, wherein the retention portion has a top retention surface, a bottom retention surface spaced from the top retention surface, and a retention portion height that extends between the top retention surface and the bottom retention surface and is substantially parallel to a second axis normal to the first axis.

19. The mixing unit of claim 18, wherein the retention portion comprises a plurality of mixing structures that extend between the top retention surface and the bottom retention surface.

20. The mixing unit of claim 19, wherein the mixing structures are arranged in a sequence of mixing structures.

21. The mixing unit of claim 20, wherein at least two of the mixing structures have different sizes and / or different shapes when viewed in a plane normal to the second axis.

22. The mixing unit of any one of claims 19-21, wherein the mixing structures are arranged in an array of mixing structures.

23. The mixing unit of any one of claims 17-22, wherein the retention portion comprises one or more heat exchange features that extend transversely from at least one of the top retention surface and the bottom retention surface and extend along the retention portion length.SP24-27324. The mixing unit of claim 23, wherein the one or more heat exchange features extend between the top retention surface and the bottom retention surface.

25. The mixing unit of claim 23 or claim 24, wherein the one or more heat exchange features extend for at least 50% of the retention portion length.

26. The mixing unit of any one of claims 23-25, wherein the one or more heat exchange features are configured as elongated fins.

27. The mixing unit of any one of claims 1-26, wherein one or more of the at least two subpassages comprises a narrowing portion that adjoins the nozzle.

28. The mixing unit of claim 27, wherein each of the at least two sub-passages comprises the narrowing portion.

29. The mixing unit of any one of claims 1-28, wherein each of the at least two sub-passages has a first sub-passage segment that extends gradually away from the first axis in the downstream direction and a second sub-passage segment that is connected to the first subpassage segment and extends abruptly towards the first axis in the downstream direction.

30. The mixing unit of any one of claims 1-29, wherein one or more of the retention portion, the wall structure, the at least two sub-passages, and the mixing chamber are symmetric about a symmetry plane of the mixing unit.

31. The mixing unit of any one of claims 1-30, wherein an upstream side of the wall structure comprises a tapering elongated end pointing in an upstream direction.

32. A fluidic device, comprising: a reactant passage configured to convey at least two reactants through the fluidic device, the reactant passage comprising at least three mixing units configured, respectively, according to any one of claims 1-31, the at least three mixing units arranged successively with the segment outlet of a preceding mixing unit adjoining the segment inlet of a succeeding mixing unit such that the reactant passage segments of each mixing unit are fluidically connected and define a portion of the reactant passage.SP24-27333. The fluidic device according to claim 32, wherein a mixing uniformity measured at the segment outlet of a sequentially first mixing unit of the at least three mixing units is at least 0.89.

34. The fluidic device according to claim 32 or claim 33, wherein a mixing uniformity measured at the segment outlet of a sequentially second mixing unit of the at least three mixing units is at least 0.95.

35. The fluidic device according to any one of claims 32-34, wherein a mixing uniformity measured at the segment outlet of a sequentially third mixing unit of the at least three mixing units is at least 0.97.

36. The fluidic device according to claim 32, wherein a mixing uniformity measured at the segment outlet of a sequentially first mixing unit of the at least three mixing units is at least 0.98.

37. The fluidic device according to claim 32 or claim 36, wherein a mixing uniformity measured at the segment outlet of a sequentially second mixing unit of the at least three mixing units is at least 0.99.

38. The fluidic device according to any one of claims 32, 36, and 37, wherein a mixing uniformity measured at the segment outlet of a sequentially third mixing unit of the at least three mixing units is at least 0.999.

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