Abstract:
A mixing apparatus for the treatment of a plurality of flowable components. The apparatus comprises an elongated housing having an upper component-introduction end and a downstream compound-discharge end. An elongated shaft is rotatably disposed within an elongated bore disposed within the housing. The shaft has a stator and rotor arrangement spaced longitudinally therearound. At least one rotor has an arrangement of fluid channeling conduits spaced apart on an annular surface thereof, wherein the conduit is of tapering narrowing dimension from a first longitudinal side of the rotor to a second longitudinal side of the rotor.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to mixing apparatus and more particularly an infinitely adjustable extrusion machine for mixing together and treating a wide variety of flowable components to create a wide variety of output products therefrom, and is based upon U.S. Provisional Patent Application Ser. No. 60/730,211, filed Oct. 25, 2005 and incorporated herein by reference in its entirety.  
         [0003]     2. Prior Art  
         [0004]     Extrusion machines have been know for many years and have been utilized in the plastic industry for the melting, mixing and converting of pellet, flakes, powders and like flowable components into extruded fibers, and polymers or the like for making plastic parts or as sheets or films or raw material for subsequent treatment and use. Controlling the conditions and the ultimate output of such multiple components has often vexed the industry, particularly where it is desirable to include in the mix, very small size particles, particularly in the nano-technology field or to create multi-phase component polymer alloys.  
         [0005]     It is an object of the present invention to provide a mixing arrangement which is variable in its mixing configuration to provide particulate output in a flow, which can be very tightly controlled and idealized for a desired use.  
         [0006]     It is a further object of the present invention to provide a mixing apparatus in which the torque and shear rate can be adjusted and controlled and components of the apparatus may be readily reconfigured to provide optimum output.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     The present invention relates to plasticating machines for mixing and incorporating multiple components such as for example, fibers, particles of wood and polymeric materials which are fed from satellite extruders. The configuration of the apparatus of the present invention comprises an elongated housing, generally of cylindrical shape, and may be split along the longitudinal, having a first or output end and a second or power drive end. The cylindrical housing has an elongated bore extending longitudinally therethrough. The elongated bore encloses a rotatable elongated shaft. The elongated shaft has an upper or driven end which is attached to a motorized drive shaft. The motorized drive shaft and the upper end of the elongated shaft are supported within bearings at the second or power drive end of the mixing apparatus. The elongated shaft at the upper or second end thereof, in the mixer apparatus has a spiral thread arranged therearound.  
         [0008]     One, two or more “satellite” extruders may be in a fluid feed communication with the threaded portion of the elongated shaft near the second or power driven end of the mixer apparatus. The satellite extruder(s) feed components of the mix to be extruded through the mixer apparatus through ports in the sidewall of the elongated cylindrical housing. The rotation of the elongated shaft by the motorized drive shaft contributes to and helps effect propulsion of the components of the mix downwardly within the cylindrical housing.  
         [0009]     The elongated shaft has a plurality of annularly shaped stators and rotors mounted within the elongated bore of that cylindrical housing. The stators and rotors configured in the present invention, may be arranged in an alternating series or may be arranged contiguous, so as to have adjacent stators and adjacent rotors or any combination thereof. The output or downstream end of the elongated shaft may have a further screw-like surface thereon at its adjacent output end. The threaded portion at the distal end presses outwardly on the extrudate and discharges it through a downstream port at the output end of the mixer apparatus.  
         [0010]     The stators may be held in place within the elongated bore within the cylindrical housing by attachment bolts secured through bolt holes within the wall of the cylindrical housing. The attachment bolts extend into a recess in the peripheral surface of that particular stator to hold it securely therewithin. The elongated shaft would extend through a central opening within that stator as will be defined here and below. A rotor for the present invention, as aforesaid, is comprised of an annular or disc shaped component having a central bore therethrough. The central bore in each rotor may have a keyway extending longitudinally therewithin. The central bore of the rotor would mate about the periphery of the rotatable elongated shaft at a desired, variably changeable location thereon.  
         [0011]     A stator similarly comprises an annular or disc shaped component having an axial bore extending longitudinally therethrough. The stator remains held in place in a stationary manner about the rotatable elongated shaft, within the elongated bore of the cylindrical housing. A first and a second bolt may be arranged through the wall of the cylindrical housing to engage to a depression within the outer peripheral wall of the stator to hold that stator secure and immovable during rotation of the elongated shaft therewithin.  
         [0012]     In a first embodiment of a stator, the central bore extends therethrough for rotation of the elongated shaft. The central bore of the stator has an annular surface with a plurality of cuts or channels arranged within it inner annular surface. The cuts or channels may in one preferred embodiment, may be angled with respect to the longitudinal axis of the bore therewithin. Those angled cuts or channels within the inner surface of the bore in the stator may be irregular or smooth. Those cuts may be in longitudinal alignment with the longitudinal axis of the stator itself or in a further preferred embodiment may be disposed at an oblique angle with respect to the longitudinal axis of the stator and rotating elongated shaft therewithin.  
         [0013]     Those cuts or channels within the internal peripheral or annular surface, or of a plurality of annularly distributed bores adjacent the inner annular surface of the stator in a further preferred embodiment thereof, may be tapered, pinched or narrowed from one longitudinal side of the stator to the other longitudinal side of the stator, preferably tapering narrower from an upstream side of the stator (or rotor) to a downstream side of the stator in a preferred embodiment thereof so as to accelerate and otherwise controllably affect the flow and manipulating of the mix thereby.  
         [0014]     In yet a further preferred embodiment of the present invention, the disc like shaped stator may have its inner or internal bore having channels or spiral cuts spaced therewithin, and the stator may also have an outer peripheral surface with similar channels or spaced apart spirally arranged cuts therein. Those channels or cuts may themselves be tapered or in a downstream direction from a wider to a narrower dimension, as well as to a radially smaller dimension from a radially larger dimension at its upstream side.  
         [0015]     Similarly, a rotor being an annular or disc shaped component having an upstream side and a downstream side with a cylindrically shaped bore extending therethrough. The rotor has a keyway which mates with a longitudinally directed key on a side of the elongated rotatable shaft to permit the rotor to engage and rotate with the elongated shaft as it rotates within the elongated bore of the cylindrically shaped housing. Each rotor has an outer peripheral surface with a plurality of channels or grooves thereon and/or with circumferentially spaced apart bores therethrough. The channels, bores and/or grooves in the rotor are preferably dimensionally changed from an upstream to a downstream dimension. Those channels or grooves are preferably narrower and smaller at the downstream side of the rotor than the upstream side.  
         [0016]     Those channels or grooves in the outer peripheral surface of the rotor may be arranged in a helical or spiral-like configuration having roughened or smooth surface therein, in a further preferred embodiment thereof. It is also contemplated that those spiral grooves or channels may be tapered to a thinner or more narrow dimension from one side of the rotor to the other up or downstream side thereof. Thus it is possible with the components of the present invention, comprising numerous rotors and stators, to adjustably set and force and dispersably mix a number of components in a desired configuration by the utilization of rotors and stators each with specific dimensions and tapers in their channel configurations. Those channels with between upstream and downstream sides of the rotors and stators as aforementioned may also comprise holes or bores instead of peripheral surface cuts as aforesaid.  
         [0017]     By developing a series of dimensional changes as you go downstream with the various stators and rotors in the bore of the cylindrical housing during a mixing operation, various outflow parameters may be set and output flows realized for particular compounds being admixed and treated. By numbering or setting a code for the channel configurations, for example, depth or width or length or roughness or dimension of taper or narrowing of channel or bore or chirality of spirals of particular rotors and stators, the mixing and processing of various compounds may be readily pre-configured, set according to a known flow/mix pattern and thus accomplished. The speed of the outflow and mixing may be increased as the mix goes through the tapered channels or bores, as through a venturri, so as to change/increase the flow rate and manipulate the desired mixing capabilities going therethrough. Improvements in such mixing and compounding may be accomplished, even on a nano scale compound.  
         [0018]     Heating of the satellite extruders and their respective input, as well as heating and/or cooling the cylindrical housing and/or the stators running therewithin, may permit further manipulation and creativity of the admixing procedure.  
         [0019]     The invention thus comprises a mixing apparatus for the treatment of a plurality of flowable components comprising: an elongated housing having an upper component-introduction end and a downstream compound-discharge end; an elongated shaft rotatably disposed within an elongated bore disposed within the housing, the shaft having a stator and rotor arrangement spaced longitudinally therearound, wherein at least one rotor has an arrangement of fluid channeling conduits spaced apart on an annular surface thereof, and wherein the channel/conduit is of tapering narrowing dimension from a first longitudinal side of the rotor to a second longitudinal side of the rotor. At least one stator has an arrangement of conduits spaced apart on an annular surface thereof, wherein the conduit is of a tapering dimension from a first longitudinal side of the stator to a second longitudinal side thereof. The first longitudinal side of the rotor may preferably correspond to an upstream side of the apparatus. The first longitudinal side of said stator preferably corresponds to an upstream side of the apparatus. At east one of the conduits may comprise a helical or spiral cut in its surface. The surface may comprise an outer annular surface on the rotor. The surface may comprise an inner annular surface on the rotor. The surface may comprise an outer annular surface on the stator. The surface may comprise an inner annular surface on the stator. At least one of the conduits may comprise a fluid treating bore extending generally longitudinally through the rotor. The fluid treating bore may have an upstream opening with a different geometrical shape than its downstream fluid flow exit opening to help achieve bi-axially oriented laminar formation of the compound during its processing.  
         [0020]     The invention also comprises a method of providing an infinitely mixing capability to a plurality of particulate-fluid components through a fluid flow path mixing apparatus, comprising one or more of the following steps: arranging an array of rotors and stators in a mixing apparatus having a component-supplied upstream end and a downstream end; forming channels in the rotors and stators, at least one of the channels having a tapered geometry; and arranging the rotors and the stators in a particular array to provide a mix and shear effect thereto, as needed for the particular components fed to said apparatus; arranging the channels in the rotors and/or stators so as to be narrowed preferably in their downstream ends, to accelerate the movement of components being moved and treated therethrough; providing indicia on the rotors and the stators to indicate a particular known geometry of the channels therein, to permit the apparatus to be programmed and readily re-assembled to permit infinite adjustment and re-setting to a desired mix result, depending upon the need for the particular components being treated therethrough.  
         [0021]     The arrangement of rotors and stators with their own channels creates flow division leading to a large increase in surface area in a multi-component feed which is very desirable for good mixing. Also the use of moving boundaries of rotors moving against stators and barrel surface leads to the creation of shear fields which vary with the geometry and rotor speed (Couette Flow). These shear fields are necessary for dispersive mixing to break up agglomerates. The use of convergent channels causes the fluid to accelerate which leads to extensional flow. The mixer apparatus creates specific morphology in the compound that affects both the physical and chemical properties and is highly desirable in multi-phase systems. The conveying action for output in the stator channels occurs via pressure flow (Poiseulle Flow). This flow sets up a shear field that is zero at the center of the channel and increases to a maximum at the wall. The apparatus of the present invention is capable of generating various mixing modes: Flow division; variable shear flow by a moving machine boundary; elongational flow due to a converging geometry and shear flow due to a pressure drop from the feed to the discharge end. Satellite mixers used with the present invention prepare the melt and components and are independently driven to feed the mixer. The mixer may be programmed for the correct shear and type of mixing via the use of particular marked rotors and stators. The speeds of the mixer andits satellite extruders are each adjustable individually to change the screw speeds. Also, each has its own barrel temperature control zones to control viscosity and torque.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The objects and advantages of the present invention will become more apparent, when viewed in conjunction with the following drawings in which:  
         [0023]      FIG. 1  is a planned view of a mixing apparatus of the present invention being fed by a pair of satellite extruders;  
         [0024]      FIG. 2  is a perspective view of the mixing apparatus shown in  FIG. 1 , without a cylindrical housing therearound;  
         [0025]      FIG. 3  is a perspective view, in section showing a stator with its channels of grooved arranged within it inner peripheral bore;  
         [0026]      FIG. 4  is a perspective view of the stator shown in  FIG. 3 , in full view of its entire outer periphery;  
         [0027]      FIG. 5  is a view of a stator having grooves within its inner bore as well as grooves and channels within it outer periphery;  
         [0028]      FIG. 6  is a sectional view of the stator shown in  FIG. 5 ;  
         [0029]      FIG. 7  is a perspective view of a rotor having its outer peripheral surface showing the tapered channels thereon; and  
         [0030]      FIG. 8  is a perspective view of a rotor with an arrangement of spirally disposed channels tapered, thereon.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]     Referring in detail to the drawings of the present invention, and particularly to  FIG. 1 , there is shown a plasticating machine  10  in a sectional plan view, for mixing, extruding and treating multiple components C 1  and C 2  fed from an arrangement of satellite extruders  12  and  14 . The mixing apparatus of the present invention comprises an elongated housing  16  generally of cylindrical shape, and may be split along the longitudinal, having a first or output end  18  and a second or power drive end  20 . The cylindrical housing  18  has an elongated bore  22  extending longitudinally therethrough. The elongated bore  22  encloses a rotatable elongated shaft  24 . The elongated shaft  24  has an upper or driven end  26  which is attached to a motorized drive shaft  28 . The motorized drive shaft  28  and the upper (second) end  20  of the elongated shaft  24  are supported within bearings  30  at the second or power drive end of the mixing apparatus  10 . The elongated shaft at the upper or second end thereof, in the mixer apparatus has a spiral thread  32  arranged therearound, as may be seen in  FIG. 1 .  
         [0032]     One, two or more “satellite” extruders  12  and  14  are be in a fluid feed communication with the threaded portion  32  of the elongated shaft  24  near the second or power driven  20  end of the mixer apparatus  10 . The satellite extruder(s)  12  and  14  feed components C 1  and C 2  of the mix to be extruded through the mixer apparatus  10  through ports  36  in the sidewall of the elongated cylindrical housing  16 . The rotation of the elongated shaft  24  by the motorized drive shaft  28  contributes to and helps effect propulsion of the components C 1  and C 2  of the mix downwardly within the bore  22  of the cylindrical housing  16 .  
         [0033]     The elongated shaft  24  has a plurality of annularly shaped stators  40  and rotors  42  mounted within the elongated bore  22  of that cylindrical housingl 6 . The stators  40  and rotors  42  configured in the present invention, may be arranged in an alternating series, as represented for example, in  FIGS. 1 and 2 , or they may be arranged contiguous, so as to have adjacent stators  40  adjacent one another and/or rotors  42  adjacent one another, or any combination thereof. The output or downstream end  25  of the elongated shaft  24  may have a further screw-like surface  44  thereon at its output end. The threaded portion  44  at the distal end of the shaft  24  presses outwardly on the extrudate C 1 C 2  and discharges it through a downstream port  46  at the output end  18  of the mixer apparatus  10 . It is to be noted that the particular stators  40  and rotors  42  may be numbered, as for example “I”, in  FIG. 8 , and categorized to permit this apparatus  10  to have a pre-set array of rotors  42  and stators  40  which will treat a specific set of components in a particular known manner which may be readily repeatable by returning to the pre-set numbers of rotors  42  and stators  40  mountable about the rotatable shaft  24 , as needed.  
         [0034]     The stators  40  may be held in place within the elongated bore  24  within the cylindrical housing  16  by attachment bolts  48  secured through bolt holes  50  within the wall of the cylindrical housing  16 . The attachment bolts  48  may extend into a recess  60  in the peripheral surface  62  of that particular stator  40 , as represented in  FIGS. 3, 4 ,  5  and  6 , to hold it securely therewithin. The elongated shaft  24  would extend through a central longitudinally directed opening  66 , as represented in FIGS.  3 ,  4 , 5  and  6 , within that stator  40  as will be further defined hereinbelow.  
         [0035]     A rotor  42  for the present invention, as represented in  FIGS. 7 and 8 , is comprised of an annular or disc shaped component having a central bore  70  therethrough. The central bore  66  in each rotor  42  may have a keyway  72  extending longitudinally therewithin. The central bore  66  of the rotor would mate about the periphery of the rotatable elongated shaft  24  at a desired, variably changeable location thereon.  
         [0036]     A stator  40 . as aforementioned, similarly comprises an annular or disc shaped component having its axial bore  66  extending longitudinally therethrough. The stator  40  remains held in place in a stationary manner about the rotatable elongated shaft  24 , within the elongated bore  22  of the cylindrical housing  16 . A first and a second bolt  48  may be arranged through the wall of the cylindrical housing  16  to engage to its depression  60  within the outer peripheral surface  62  of the stator  40  to hold that stator  40  secure and immovable during rotation of the elongated shaft  24  therewithin.  
         [0037]     In a first embodiment of a stator  40 , as represented in  FIG. 3 , the central bore  66  extends therethrough for rotation therethrough of an elongated shaft. The central bore  66  of the stator  40  has an annular surface  74  shown in  FIG. 5 , with a plurality of cuts or channels  80  arranged in its inner annular surface  74 . The cuts or channels  80  may in one preferred embodiment, may be angled with respect to the longitudinal axis “L” of the bore therewithin. Those angled cuts or channels  80  within the inner surface  74  of the bore in the stator  40  may be irregular, that is roughened as shown in  FIG. 4  or smooth, as represented in  FIG. 5 . Those cuts may be in longitudinal alignment with the longitudinal axis “L” of the stator  40  itself or in a further preferred embodiment may be disposed at an oblique angle with respect to the longitudinal axis “L” of the stator  40  and the axis of a rotating elongated shaft therewithin. The tapered channels may be conical or narrowed to provide acceleration to the compounds working its way downstream, or the tapers may be narrow at their upstream end to slow down the movement of the mix. During the “accelerated” fluid flow, the particulate mix is elongated from rotor/stator to stator/rotor. The flow pattern may thus be changed and controlled depending upon the channel geometries in the stators and rotors to provide an infinitely variable shear mix path of components being fed to the apparatus  10 .  
         [0038]     Those cuts or channels  80  within the internal peripheral or annular surface  74 , or of a plurality of annularly distributed bores  86  (which bores  86  may have oval, circular, elliptical or rectilinear upstream/downstream inlets and outlets, which inlets and outlets may differ from one another in size and shape, not shown for clarity of view) adjacent the inner annular surface  74  of the stator  40 , as represented in  FIG. 4 , or through a rotor  42  in a further preferred embodiment thereof, as represented in  FIG. 7 , may be tapered from one longitudinal side of the stator  40  (or rotor  42 , as in  FIG. 7 ), to the other longitudinal side of the stator  40 , preferably tapering narrower from an upstream side of the stator  40  to a downstream side of the stator  40  in a preferred embodiment thereof so as to accelerate and otherwise controllably affect the flow and manipulation of the mix thereby.  
         [0039]     In yet a further preferred embodiment of the present invention, the disc like shaped stator  40  may have its inner or internal bore  74  having channels  80  as spiral cuts  83  spaced therewithin, and the stator  40  may also have an outer peripheral surface  88  with similar channels  90  or spaced apart spirally arranged cuts  92  therein, as represeneted in  FIGS. 5 and 6 . Those channels or cuts  90  and  92  may themselves be tapered or in a downstream direction from a wider to a narrower dimension, as well as to a radially smaller dimension from a radially larger dimension at its upstream side.  
         [0040]     Similarly, a rotor  42  being an annular or disc shaped component having an upstream side  96  and  98  and a downstream side with a cylindrically shaped bore  70  extending therethrough, is represented in  FIGS. 7 and 8 . The rotor  42  has its keyway  72  to mate with a longitudinally directed key, not shown for clarity of drawings, on a side of the elongated rotatable shaft  24 , to permit the rotor  42  to engage and rotate with the elongated shaft  24  as it rotates within the elongated bore  22  of the cylindrically shaped housing  16 . Each rotor  42  has an outer peripheral surface  100  with a plurality of channels or grooves  102  thereon and/or with circumferentially spaced apart bores  86  therethrough, as represented in  FIG. 7 . The channels  92 , bores  86  and/or grooves  92  in the rotor  42  are preferably dimensionally changed from an upstream to a downstream dimension. Those channels or grooves  92  or bores  86  are preferably narrower and smaller at one side, preferably the downstream side of the rotor  42  than the upstream side.  
         [0041]     Those channels or grooves  102  in the outer peripheral surface  100  of the rotor  42  may be arranged in a spiral-like configuration, shown in  FIG. 8 , having roughened or smooth surface therein, in a further preferred embodiment thereof. It is also contemplated in a further embodiment, that those spiral grooves or channels  102  may be tapered to a thinner or more narrow dimension from one side of the rotor  42  to the other up or downstream side thereof. Thus it is possible with the components of the present invention, comprising numerous rotors and stators, to adjustably set and force and dispersably mix a number of components in a desired configuration by the utilization of rotors and stators each with specific dimensions and tapers in their channel configurations. Those channels  88 ,  92  with between upstream and downstream sides of the rotors and stators as aforementioned may also comprise holes or bores  86  instead of peripheral surface cuts as aforesaid.  
         [0042]     By developing a series of dimensional changes going downstream with the various stators  40  and rotors  42  in the bore  22  of the cylindrical housing  16  during a mixing operation, various outflow parameters may be set and output flows realized for particular compounds being admixed and treated. By numbering or setting a code for the channel configurations, for example, depth or width or length or roughness or dimension of taper or narrowing of channel or bore or chirality of spirals of particular rotors and stators, the mixing and processing of various compounds may be readily pre-configured, set according to a known flow/mix pattern and thus accomplished. The speed of the outflow and mixing may be increased as the mix goes through the tapered channels or bores, as through a venturri, so as to change/increase the flow rate, elongating the fluid components as they flow downstream through the channels/bores and manipulate the desired mixing capabilities going therethrough. Improvements in such mixing and compounding may be accomplished, even on a nano scale compound.  
         [0043]     Heating of the satellite extruders  12  and  14 , and their respective input, as well as heating and/or cooling the cylindrical housing  16  and/or the stators  40  running therewithin, may permit further manipulation and creativity of the admixing procedure, being able to treat the components, even nano-sized components dispersively, to blend them in a dispersive and distributive manner, increasing the surface area of the compound by biaxial admixing thereof.