Abstract:
Inter connectors for fluidically connecting reactor modules in a millimeter scale continuous flow reactor or the like is disclosed, the interconnectors including a honey-comb-body substrate having first and second ends and a plurality of channels extending along a common direction as well as a structure formed on or in the substrate for attaching an interface clamp to the substrate. The interconnectors further have one or more open channnels extending through the substrate and a plurality of closed channels closed off by a plugging material at the ends of the substrate and surrounding the one or more open channels. Methods of making the interconnectors are also disclosed.

Description:
[0001]    This application claims the benefit of priority of U.S. application Ser. No. 61/349,983 filed on May 31, 2010. 
       BACKGROUND 
       [0002]    This disclosure relates in general fluid to interconnectors for continuous flow chemical reactors general having continuous flow passages of millimeter scale hydraulic diameter, and in particular to fluidic interconnectors fabricated from honeycomb extrusion substrates and to methods for providing such interconnectors. 
       SUMMARY 
       [0003]    According to one embodiment of the present disclosure, an interconnector for fluidically connecting reactor modules in a millimeter-scale continuous flow reactor or the like is provided, the interconnectors including a honeycomb-body substrate having a plurality of channels extending along a common direction and a structure formed on or in the substrate for attaching an interface clamp to the substrate. The interconnectors have one or more open channels extending through the substrate and a plurality of closed channels closed off by a plugging material at the ends of the substrate and surrounding the one or more open channels. 
         [0004]    According to another embodiment of the present disclosure a method of making a fluidic connector for fluidically connecting reactor modules in a millimeter scale continuous flow reactor is provided, the method comprising: (1) machining or cutting out a smaller extruded body substrate from a larger green extruded body, the substrate having channels extending along a common direction, the substrate having first and second ends from which and to which the channels extend; (2) machining or otherwise forming one or more structures in or on the substrate for attaching an interface clamp to the substrate; and (3) plugging a plurality of the channels with a plugging material at both ends of the substrate, the plurality of channels being plugged positioned around and surrounding one or more contiguous open channels. 
         [0005]    Other features and advantages of the present invention will be apparent from the figures and following description and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0006]      FIG. 1  is a perspective views of one embodiment a component of honeycomb-body based fluidic interconnector; 
           [0007]      FIG. 2  is a perspective views of another embodiment of a component of honeycomb-body based fluidic interconnector; 
           [0008]      FIG. 3  is a perspective views of one embodiment of component of a honeycomb-body based fluidic interconnector; 
           [0009]      FIG. 4  is a perspective view of the embodiment of the honeycomb-body based fluidic interconnector of  FIG. 3  with additional components; 
           [0010]      FIG. 5  is a cross-sectional view of the embodiment of a honeycomb-body based fluidic interconnector of  FIG. 4 ; 
           [0011]      FIG. 6  is a cross-sectional view of an alternative embodiment of a honeycomb-body based fluidic interconnector, alternative to  FIG. 5 . 
           [0012]      FIG. 7  is a cross-section view of an embodiment of a monolithic interconnector connected between two fluidic modules according to one aspect of the present disclosure; 
           [0013]      FIG. 8  is a cross section of an embodiment of a honey-comb-body-based interconnector with integrated heat exchange; 
           [0014]      FIG. 9  is a plan view cross-section of the interconnector of  FIG. 8 ; 
           [0015]      FIG. 10  is a cross section of a honey-comb-body-based interconnector (monolithic interconnector) with an integrated clamping structure; 
           [0016]      FIGS. 11 and 12  are plan views of an end face of two different embodiments of honey-comb-body-based interconnectors; and 
           [0017]      FIG. 13  is a cross section of a multiple-path honeycomb-based interconnector according to yet another embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The present inventor and various colleagues have previously developed the capability to provide complex continuous flow chemical reactors built up from glass or other-material fluidic modules generally having flow passages with hydraulic diameters in the millimeter range. See, for example, patents and/or patent publication Nos. U.S. Pat. No. 7,007,709 and EP1854543, issued to the present assignee. Fluidic interconnectors are required between glass fluidic modules to convey reactants from one module to another. The fluidic interconnectors must meet all or most of the requirements currently addressed by the glass fluidic modules, such as high pressure resistance, operation over a wide temperature range, and resistance to chemical erosion from a broad range of reactants. Providing fluidic interconnectors capable of both high pressure and high temperature operation can be difficult. Additionally, fluidic interconnectors desirably have a relatively small internal volume and corresponding low resulting residence time, particularly because fluidic interconnectors are generally not capable of maintaining the temperatures of reactants within the interconnector at a fixed value, so that residence time in the interconnector is desirably minimized. 
         [0019]    This disclosure describes a technique for providing interconnectors for micro-reactor fluidic modules using a monolithic interconnector device, of which the basic features and desirable fabrication method for a few embodiments will be described with reference to  FIGS. 1-4 . Monolithic interconnector devices are desirably fabricated by first machining green honeycomb extrusion substrates  20 .  FIG. 1  shows an example where a rectangular substrate  20  having multiple parallel channels  22  has been sawed out of a larger extrusion, and then one or more machined regions  24  have been formed, in this case on two on opposing sidewalls of the four sidewalls of the substrate  20 . This machining may be carried out rapidly using a sanding belt and a fixturing jig, for example. Other cutting or grinding tools may also be used, including laser cutters, water jets, or other suitable technologies. In the embodiment shown, formation of the machined region produces two ledges  25  near each end face that may be engaged by an external clamp or clamping fixture  40  such as that shown in  FIG. 7  to hold the resulting monolithic interconnector  10  in contact with a reactor fluid module  40  and an interface O-ring  36 . The machined region  24  may also be formed on three or four substrate sidewalls, as shown in the embodiment of  FIG. 2 . If desired, machined features other than or in addition to ledges may be formed and used to hold the part in contact with an adjacent reactor fluidic module, such as notches, slots and holes (not shown) that engage the clamp  42 . 
         [0020]    As seen in  FIG. 3 , after machining is complete the part is sintered and plug material  26  is applied to selected ones of the channels  22  at the end faces of the substrate  20  such that one or more end face channels  32  remain unplugged. These unplugged channel(s)  32  will serve to guide reactant fluid or other process fluid thorough the monolithic interconnector  10  from a first process fluid port  28  to a second one  30 . 
         [0021]    After substrate end face plugging the end face plug material  26  may be polished to serve as an O-ring bearing surface. Alternatively a plug sintering process may leave the end face plug material  26  in a naturally smooth state due to plug softening and flow so that polishing is not required. 
         [0022]    Prior to assembly in a reactor system O-rings  34  may be applied on each end face of the monolithic interconnector  10  as shown in  FIG. 5 . O-ring plates  36  may also be positioned on the end faces to restrain the O-rings during assembly and in use. 
         [0023]    As an alternative to O-ring plates  26 , the O-ring(s)  34  may be restrained by molding O-ring groove features  27  into the substrate end face plug material  26  prior to sintering as shown in  FIG. 6 . The O-ring groove desirably be formed of glass frit in these embodiments. The O-ring support may be made more robust by having a broad area of the plugging material  26  raised as in  FIG. 6 , and not just a small circular region of material, so that the O-ring  34  is restrained during pressurization by a larger region or cross section of material. 
         [0024]    A thin resilient layer  38  such as a polymer material with pressure sensitive adhesive backing may be applied to a portion of plugged end face to prevent glass-glass or glass-ceramic contact at the end face during assembly. 
         [0025]      FIG. 7  provides a cross-section view of a monolithic interconnector positioned between two glass fluidic modules. Two interface clamps  42  hold the monolithic interconnector  10  in position against respective glass fluidic modules  40  by engaging the ledge features near each end face. A clamp screw integral  44  to the interface clamp  42  may be turned to force the monolithic interconnector  10  to compress the O-ring  36  at each end face. 
         [0026]    Clamp pads  48  may be positioned between the interface clamp and the monolithic interconnector ledge features to serve as a force spreader. The monolithic interconnector ledges may also include a corner fillets to minimize stress concentrations associated with sharp corners under or near the loading point on the ledge. 
         [0027]    An advantage of using a ceramic monolithic interconnector device is that device length changes due to excessively hot or cold reactant fluid flow will be minor Consider a configuration where glass fluidic modules are joined by more than one interconnector: One interconnector could convey reactant fluid while two others could deliver heat exchange fluid. The low CTE of the ceramic monolithic interconnector will ensure that the O-ring compression changes among the various interconnector O-rings will be minimal This performance is in contrast to PTFE/PFA interconnector materials, which are expected to change shape under thermal cycling. 
         [0028]    The interface clamp can also be used to hold a non-honeycomb-body-based fluidic module O-ring interface component  50  in position. As shown at the top of  FIG. 7 , a non-honeycomb-body-base fluidic module O-ring interface component  50  may be mounted on one side of a glass fluidic module  40  (on the top side of the upper fluidic module  40  in this case), while the monolithic interconnector  10  nay be positioned over a fluidic port opposite the interface component  50  on the other side of the fluidic module  40 . While  FIG. 7  shows a monolithic interconnector  10  directly joining two glass fluidic modules  40 , other configurations are possible, such as conditions where one monolithic interconnector is directly joined to another monolithic interconnector to extend the interconnector distance. In this case the interface clamp like the clamp  42  shown in  FIG. 7  would be modified to grip the ledges on two mated monolithic interconnector devices. 
         [0029]    Fluidic interconnectors between glass fluidic modules do not typically provide heat exchange fluid in close proximity to internal channels. Therefore special considerations must be made to minimize the internal volume of the fluid interconnector. If the internal volume of the fluid interconnector is too large, undesirable reaction side products may be generated as a consequence of the uncontrolled temperature within the interconnector device. 
         [0030]    One potential advantage of using honeycomb extrusion substrates as monolithic interconnector devices is that channels adjacent to internal reactant channels can be used as heat exchange fluid channels.  FIG. 8  provides a cross-section view of a monolithic interface where two side ports  58  have been added (with two shown but only one directly labeled in the figure). Heat exchange fluid O-rings  56  with corresponding interface fittings  54  are positioned over these side ports  58  so that heat exchange fluid may be injected into the monolithic interconnector on one side and removed on the other side, resulting in heat exchange fluid path  60  shown by the arrows in the figure. Inside the monolithic interconnector device  10  the heat exchange fluid may be routed along one or more serpentine up-and-down paths through the substrate  20 . The serpentine path is defined via plunge machining operations or other suitable machining operations that form U-bends at various locations along the serpentine path. See, for example, the disclosure of US Patent Publication No. 20090169445, assigned to the present assignee. As shown in more detail in that publication, the U-bends result from the selective lowering of substrate walls, in combination with the plugs formed by plug material  26 . The lowered walls  62  as indicated in  FIG. 7  are lower or deeper into the substrate  20  than the plug material  26 , thus allowing the heat exchange fluid to flow from channel to channel within the substrate  20  in a direction cross-wise to the common direction of the channels around a “U-bend.” 
         [0031]      FIG. 9  shows a plan view cross-section of the monolithic interconnector internal channels of the monolithic interconnector of  FIG. 8 , illustrating how heat exchange fluid that enters the substrate  20  follows a path  60 A within the substrate  20 , being is directed upward and downward along two serpentine paths that pass on each side of the reactant channel  64  before joining at the fluid outlet. If desired, pressure drop along the heat exchange path may be further reduced using the side port designs such as those presented in FIGS. 12-14 of US Patent Publication No. 20090169445, mentioned above. 
         [0032]    Part count and cost of a reactor system may potentially be reduced by integrating the interface clamp function with the monolithic interconnector as in the embodiment shown in  FIG. 10 , in which only the upper monolithic interconnector O-ring interface is shown for ease of illustration. 
         [0033]    In the embodiment of  FIG. 10 , a honey-comb based interconnector (monolithic interconnector) with integrated clamp  12  is machined from a single piece of ceramic honeycomb extrusion substrate material while in the green state to produce a recess  70  for receiving a fluidic module  40 . After sintering and plugging, a threaded bushing  66  is inserted into a hole drilled into the substrate parallel to the extrusion axis. The clamp screw  44  is threaded into this bushing  66  so that force is applied to the glass fluidic module  40  when the screw  44  is tightened. The clamping portion of the monolithic interconnector with integrated clamp  12  is made more robust and resistant to failure under mechanical stress by controlling the radius at the inside corners  72  of the device during manufacture to make sure it is sufficiently large. 
         [0034]      FIGS. 11 and 12  show plan views of monolithic interconnectors  10  with single ( FIG. 11 ) and multiple ( FIG. 12 ) parallel channels for a single interconnector. At high fluid flow rates the small cross-section associated with a single monolithic interconnector reactant channel  32  as in  FIG. 11  may introduce undesirable high pressure drop across the device. This pressure drop may be reduced without compromising the mechanical integrity of the monolithic interconnector device  10  by employing multiple reactant channels  32  running adjacent to each other in parallel through the same substrate as in the embodiment of  FIG. 12 . 
         [0035]      FIG. 13  shows multiple-path honeycomb-based interconnector (monolithic interconnector)  14  according to another alternative embodiment of the present invention. The monolithic interconnector  14  of  FIG. 13  supports multiple fluidic interconnectors in parallel within a single substrate  20 . This can further reduce the total piece count in a reactor system by providing in a single monolithic interconnector multiple fluidic channels for different fluids that extend into or through the same substrate. The cross-sectional view of  FIG. 13  shows a monolithic interconnector device  14  with three separate internal channels in the plane of the cross section. This approach can simplify the assembly of chemical reactors, since fewer components must be joined to assemble a complete reactor, thus reducing costs. 
         [0036]    The monolithic interconnectors  19 ,  12 ,  14  of the present disclosure may be fabricated in ceramic materials (e.g., alumina) to provide pressure resistance, resistance to chemical erosion and operation over a broad temperature range. While alumina is currently preferred, other ceramics, glass, and glass-ceramics could also be beneficially employed. 
         [0037]    Although the modules  40  to be interconnected are depicted in the figures herein as flat layered fluidic modules, the same interconnector principles and interconnectors  10 ,  12 ,  14  herein disclosed may be beneficially used for other types of fluidic modules, including fluidic modules or fluid processing structures formed in honeycomb substrates. 
         [0038]    The various embodiments of the methods and devices of the present disclosure provide one or more of the following significant advantages: The monolithic interconnectors may be easily fabricated in ceramic materials (e.g., alumina) to provide pressure resistance, resistance to chemical erosion and operation over a broad temperature range. Such substrates also remain rigid over a broad temperature range (unlike PTFE or other polymer interconnector materials). Low pressure drop fluidic interconnectors are possible, particularly by using multiple channels in parallel. The same substrate can be used to provide fluid interconnectors among multiple fluidic module input and output ports. The required monolith interconnector features are relatively easy to fabricate by machining in green honeycomb extrusion substrates. Packaging cost of the reactor can be reduced, and/or performance increased by integrating certain functions, such as clamping and/or heat exchange, into the body of the monolithic interconnector. When multiple fluidic interconnector paths are provided in a single substrate, overall part count and assembly complexity is reduced. 
         [0039]    The methods and/or devices disclosed herein are generally useful in performing any process that involves mixing, separation, extraction, crystallization, precipitation, or otherwise processing fluids or mixtures of fluids, including multiphase mixtures of fluids—and including fluids or mixtures of fluids including multiphase mixtures of fluids that also contain solids—within a microstructure. The processing may include a physical process, a chemical reaction defined as a process that results in the interconversion of organic, inorganic, or both organic and inorganic species, a biochemical process, or any other form of processing. The following non-limiting list of reactions may be performed with the disclosed methods and/or devices: oxidation; reduction; substitution; elimination; addition; ligand exchange; metal exchange; and ion exchange. More specifically, reactions of any of the following non-limiting list may be performed with the disclosed methods and/or devices: polymerization; alkylation; dealkylation; nitration; peroxidation; sulfoxidation; epoxidation; ammoxidation; hydrogenation; dehydrogenation; organometallic reactions; precious metal chemistry/homogeneous catalyst reactions; carbonylation; thiocarbonylation; alkoxylation; halogenation; dehydrohalogenation; dehalogenation; hydroformylation; carboxylation; decarboxylation; amination; arylation; peptide coupling; aldol condensation; cyclocondensation; dehydrocyclization; esterification; amidation; heterocyclic synthesis; dehydration; alcoholysis; hydrolysis; ammonolysis; etherification; enzymatic synthesis; ketalization; saponification; isomerisation; quaternization; formylation; phase transfer reactions; silylations; nitrile synthesis; phosphorylation; ozonolysis; azide chemistry; metathesis; hydrosilylation; coupling reactions; and enzymatic reactions. 
       Reference Key 
       [0040]      10  honeycomb-based interconnector (monolithic interconnector) 
         [0041]      12  honey-comb based interconnector (monolithic interconnector) with integrated clamp 
         [0042]      14  multiple-path honeycomb-based interconnector (monolithic interconnector) 
         [0043]      20  honeycomb extrusion substrate (portion sawed out from larger) 
         [0044]      22  channels 
         [0045]      24  machined region 
         [0046]      25  ledges (formed by  24  on  20 ) 
         [0047]      26  plugging material 
         [0048]      27  O-ring groove features 
         [0049]      28  (first) fluid port 
         [0050]      30  (second) fluid port 
         [0051]      32  (reactant or process fluid) fluid channel (of  22 ) through  20  after plugging (connecting  28  to at least  30  another) 
         [0052]      34  O-ring 
         [0053]      36  O-ring plate 
         [0054]      38  compressible layer (thin polymer sheet with pressure sensitive adhesive backing) 
         [0055]      40  (glass) fluidic module 
         [0056]      42  interface clamp(s) 
         [0057]      44  clamp screw 
         [0058]      46  screw pad 
         [0059]      48  clamp pad 
         [0060]      50  (generic) O-ring interface for standard or other (typically external access) fluid couplings 
         [0061]      52  (additional) O-ring 
         [0062]      54  (heat-exchange) O-ring interface(s) 
         [0063]      56  (heat exchange) O-ring(s) 
         [0064]      58  (heat exchange) fluid port(s) 
         [0065]      60  heat exchange fluid path 
         [0066]      60 A heat exchange path (heat exchange channels) within  20   
         [0067]      62  lowered wall(s) 
         [0068]      64  reactant (process) fluid path 
         [0069]      66  threaded bushing 
         [0070]      68  force spreader 
         [0071]      70  recess (in  20  for receiving  40 ) 
         [0072]      72  controlled radius corner (in  70 )