Abstract:
A low pressure plural component mixing nozzle for mixing plural component materials for coating the interior of small diameter conduits. A body defines a first passageway that extends from a right to a left side. The body further defines a second passageway communicating an inlet side with the first passageway proximate the right side and defining a third passageway communicating the inlet side with the first passageway proximate the left side. A fourth passageway passes through the body from the inlet side to the exit side. A mixer, such as a mixing cartridge, is located in the first passageway for mixing a fluid from the second passageway and a fluid from the third passageway and directing a mixture of the fluids into contact with fluid flowing through the fourth passageway wherein the mixture flows to an exit nozzle on a distal end of the body stem for exiting the device.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of U.S. Provisional Patent Application No. 61/159,594 entitled “MIXING NOZZLE FOR PLURAL COMPONENT MATERIALS,” filed Mar. 12, 2009, the contents of which are hereby incorporated by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    This invention was made with government support under NSF grant No. EEC-0332723 awarded by the National Science Foundation. The government has certain rights in the invention. 
     
    
     FIELD OF THE INVENTION 
       [0003]    The invention relates to a mixing nozzle for mixing plural component materials. In particular, the invention relates to a low pressure nozzle for mixing plural component materials wherein the device may be used to dispense fluids in small diameter conduits. 
       BACKGROUND OF THE INVENTION 
       [0004]    Polyurea coatings are ideal for sealing and lining air ducts and other tubes and pipes. However, there are difficulties associated with mixing nozzles used to apply plural compounds to the interior of small, e.g., 4 to 6 inch ID, pipes. Existing mixing and application devices fall into one of two categories: high pressure guns and low pressure nozzles with static mixing tubes. Known guns are too large and their spray patterns are typically small diameter, for application to pipe interiors. Further, high pressure applicators are expensive to purchase and maintain. Furthermore, high pressure applicators may run at pressures of 2000 to 4000 psi, which raises safety concerns. Static mixing tubes used in low pressure systems must be changed each time the application is halted. No known nozzles are available for applying a plural compound mixture to pipe interior walls. Therefore, it is desirable to provide a device that is capable of mixing polyurea and other elastomers at low pressure and that is capable of applying the mixture to the interiors of small diameter pipes. It is further desirable that the device be self-cleaning and have no moving parts. 
       SUMMARY OF THE INVENTION 
       [0005]    In one embodiment, the device of the invention utilizes two opposed passages to impinge two fluid components, e.g., elastomer or polyurea components, on each other. The fluid components are extruded at high velocity through slots or, alternatively, through a ring orifice oriented perpendicular to the impinging fluid components. Width of the slots is preferably 0.013 ( 1/32) inch wide. Width of the orifice is preferably 0.010 to 0.020 inches. In the ring orifice embodiment, the thickness of the two fluid disks created by fluid passing through the ring orifice decreases to approximately half the orifice width as the disk expands radially. In another embodiment, a mixing tube defines the two opposed passages. Each passage delivers its contents to a plurality of quasi-radial mixing ports that exit from common radial ports. The fluid is dispersed radially through the common radial ports to form a circular pattern that will be referred to herein as a fluid disk. 
         [0006]    A high velocity air jet fractures the disk into fine droplets. The droplets are conveyed by an air stream to a small diameter passage in a nozzle. Droplets of the two components are further mixed in this passage. The three fluid mixture, i.e., air or gas and the two mixed fluids, exits radially from the nozzle core at the face of a circular deflector attached to the nozzle core. In one embodiment, these streams impinge on a chamfered edge of the nozzle barrel and circular deflector to form an expanding radial cone of the three fluids. The apex angle of the cone can be varied from 90 to 180 degrees. In another embodiment, the stream exits radially from overlapping slots defined by a nozzle barrel. The conical three fluid stream impinges on the interior surface of the duct or pipe for coating the pipe. 
         [0007]    The device blends the fluid components instantaneously at low operating pressures. The device incorporates a third fluid, e.g., air, and produces very small droplets from a highly viscous material. Because of the orientation and incorporation of the air stream, the nozzle is self-cleaning. A conical or disk spray pattern can be formed because the stream is high velocity and consists of three fluids. The air or gas stream entrains the droplets, e.g., of a polyurea mixture, accelerating their velocity, and distributing the droplets in the conical or disk pattern. 
         [0008]    In another embodiment, the device uses an auger-like device to mix two fluids as the fluids traverse a length of a mixing tube. The mixed fluids are then further mixed in a mixing area with a third fluid, e.g., air, before the three fluids are dispersed out of spray slits. 
         [0009]    In a third embodiment, the device utilizes a third fluid, e.g., that may be delivered via a round or slot shaped section of a fourth passageway to pass over dispersing slots of a mixing cartridge. The air or gas stream entrains the droplets, e.g., of a polyurea mixture, accelerating their velocity, and distributing the droplets in the conical or disk pattern. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of a plural component three fluid/atomizing mixing nozzle. 
           [0011]      FIG. 2  is a sectional view of the plural component three fluid mixing/atomizing nozzle of  FIG. 1 . 
           [0012]      FIG. 3  is a sectional view of an alternate embodiment of the plural component three fluid atomizing/mixing nozzle of the invention. 
           [0013]      FIG. 4  is a perspective view of the mixing tube of the embodiment of  FIG. 3 . 
           [0014]      FIG. 5  is a partial cut-away perspective view of an embodiment of  FIG. 3 . 
           [0015]      FIG. 6  is a cross-sectional elevation view of the embodiment of  FIG. 5 . 
           [0016]      FIG. 7  is a cross-sectional perspective view of an alternate embodiment of the plural component three fluid atomizing/mixing nozzle of the invention with 4-segment slot orifice nozzle having overlapping slots. 
           [0017]      FIG. 8  is a cross-sectional elevation view of the embodiment of the plural component three fluid atomizing/mixing nozzle of the invention of  FIG. 7 . 
           [0018]      FIG. 9A  is an isometric view of the mixing cartridge of the embodiment of  FIGS. 7 and 8 . 
           [0019]      FIG. 9B  is a cut-away view of the mixing cartridge of the embodiment of  FIGS. 7 and 8 . 
           [0020]      FIG. 10A  is a cut-away view of the body of the mixing nozzle of  FIGS. 7 and 8  showing an oval shaped aperture for focusing an air stream. 
           [0021]      FIG. 10B  is a cut-away view of the body of the mixing nozzle of  FIGS. 7 and 8  showing a round air stream passageway. 
           [0022]      FIG. 11A  is a perspective view of a nozzle tip having overlapping slots. 
           [0023]      FIG. 11B  is a cut-away view of a nozzle tip having overlapping slots. 
           [0024]      FIG. 12A  is a perspective view of a nozzle tip having a helical slot. 
           [0025]      FIG. 12B  is a cut-away view of a nozzle tip having a helical slot. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    Referring now to  FIGS. 1 and 2 , shown is a plural component mixing nozzle designated generally  10 . Nozzle  10  is made up of a body  12 , having an inlet side  14 , an exit side  16 , a right side  18  and a left side  20 . Body  12  defines a first passageway  22  ( FIG. 2 ) that extends from right side  18  to left side  20 . Body  12  further defines a second passageway  24  that communicates inlet side  14  with first passageway  22  proximate right side  18 . Body  12  further defines a third passageway  26  that communicates inlet side  14  with a first passageway  22  proximate left side  20 . 
         [0027]    Body stem  28  extends from exit side  16  of body  12 . Body  12  and body stem  28  define a fourth passageway  30  ( FIG. 2 ) that passes through body stem  28  and body  12 . 
         [0028]    Right plug  32  is received in first passageway  22  at right side  18  of body  12 . Right plug  32  has a stem  34  that defines a circumferential passageway  36 . As shown in  FIG. 2 , when right plug  32  is inserted into first passageway  22 , circumferential passageway  36  communicates with second passageway  24 . Right plug  32  further defines a longitudinal passageway  38  ( FIG. 2 ) that communicates with circumferential passageway  36  at a first end of longitudinal passageway  38  and communicates with a distal end of stem  34  at a second end of longitudinal passageway  38 . 
         [0029]    Left plug  40  is received in first passageway  22  at left side  20  of body  12 . Left plug  40  has a stem  42  ( FIG. 2 ) that defines a circumferential passageway  44 . When left plug  40  is inserted in first passageway  22 , circumferential passageway  44  communicates with third passageway  26 . Left plug  40  further defines a longitudinal passageway  46 . Longitudinal passageway  46  communicates with circumferential passageway  44  at a first end of longitudinal passageway  46  and communicates with a distal end of stem  42  at a second end of longitudinal passageway  46 . 
         [0030]    When right plug  32  and left plug  40  are installed within first passageway  22 , distal end of stem  34  of right plug  32  and distal end of stem  42  of left plug  40  are located adjacent one another in fourth passageway  30  to define a ring orifice  48  ( FIG. 2 ). In a preferred embodiment, ring orifice  48  is formed by distal ends of stems  34 ,  42  spaced apart from one another by a distance of between 0.005 and 0.025 inches. 
         [0031]    Center member  50  is received in fourth passageway  30  on inlet side  14  of body  12 . Center member  50  defines a center fluid inlet  52  for delivering a fluid into fourth passageway  30  for flowing past ring orifice  48 . 
         [0032]    A nozzle sleeve  54  is threadably received on a distal end of body stem  28 . Nozzle sleeve  54  preferably has a tapered outlet end  56 . Nozzle barrel member  58  ( FIG. 2 ) is received within nozzle sleeve  54 . 
         [0033]    A circular deflector  62  is received proximate an outside end of nozzle sleeve  54 . Circular deflector  62  defines a plurality of radial orifices  64  ( FIG. 2 ) that communicate an inside of nozzle barrel member  58  with an inside surface of a flange portion of circular deflector  62 . The inside surface of the flange portion of circular deflector  62  and the tapered outlet end  56  of nozzle sleeve  54  define a circumferential spray gap  66  for receiving fluids from the plurality of radial orifices  64  and dispersing the fluids in a conical spray configuration. 
         [0034]    Referring now to  FIG. 3 , shown is an alternate embodiment of a plural mixing nozzle, designated generally  100 . Nozzle  100  is made up of a body  112 , having an inlet side  114 , an exit side  116 , a right side  118 , and a left side  120 . Body  112  defines a first passageway  122  ( FIG. 3 ) that extends from right side  118  to left side  120 . Body  112  further defines a second passageway  124  that communicates inlet side  114  with first passageway  122  proximate right side  118 . Body  112  further defines a third passageway  126  that communicates inlet side  114  with a first passageway  122  proximate left side  120 . 
         [0035]    Body stem  128  extends from exit side  116  of body  112 . Body  112  and body stem  128  define a fourth passageway  130  ( FIG. 3 ) that passes through body stem  128  and body  112 . 
         [0036]    An atomizing and blending cartridge, referred to herein as mixing cartridge  132  ( FIGS. 3 ,  4 ) is received in first passageway  122 . Mixing cartridge  132  defines a right circumferential passageway  136 . As shown in  FIG. 3 , when mixing cartridge  132  is inserted into first passageway  122 , right circumferential passageway  136  communicates with second passageway  124 . Mixing cartridge  132  further defines a right longitudinal passageway  138  ( FIGS. 3 ,  4 ) that communicates with circumferential passageway  136  proximate a first end of longitudinal passageway  138  and communicates with a first plurality of quasi-radial passageways  139  proximate a center of mixing cartridge  132  at a second end of longitudinal passageway  138 . In a preferred embodiment, twelve quasi-radial passageways  139  are drilled at a 30° angle from a plane that is perpendicular to the longitudinal axis of mixing cartridge  132 . 
         [0037]    Mixing cartridge  132  defines a left circumferential passageway  144  ( FIGS. 3 ,  4 ). When mixing cartridge  132  is inserted in first passageway  122 , left circumferential passageway  144  communicates with third passageway  126 . Mixing cartridge  132  further defines a left longitudinal passageway  146  ( FIG. 3 ). Left longitudinal passageway  146  communicates with circumferential passageway  144  proximate a first end of left longitudinal passageway  146  and communicates with a second plurality of quasi-radial passageways  147  ( FIG. 3 ) proximate a center of mixing cartridge  132  at a second end of longitudinal passageway  146 . In a preferred embodiment, twelve quasi-radial passageways  139  are drilled at a 30° angle from a plane that is perpendicular to the longitudinal axis of mixing cartridge  132 . Longitudinal passageway  138  and longitudinal passageway  146  are separated from one another by partition  149 . 
         [0038]    Right stopper  148  and left stopper  149  are secured at right and left ends of first passageway  122  to secure mixing cartridge  132  within first passageway  122  of body  112 . Right plurality of quasi-radial passageways  139  and left plurality of quasi-radial passageways  147  meet at common exit orifices defined by an external surface of mixing cartridge  132 , i.e., at center mixing ports  151  ( FIGS. 3 ,  4 ), which distribute mixed fluid radially from mixing cartridge  132  in a quasi-disk pattern. The common mixing ports  151 , fed from passageways  139 ,  147 , assure that components flowing through longitudinal passageways  138  and  146  are blended in a 50:50 ratio. Further mixing and conveyance by the air stream is similar to those described in the first embodiment. 
         [0039]    Fluid enters into fourth passageway  130  proximate inlet side  114  for flowing past the fluid disk pattern formed by fluid exiting from center mixing ports  151 . 
         [0040]    Referring back primarily to  FIG. 3 , a flanged nut  154  is threadably received on a distal end of body stem  128 . Flanged nut  154  preferably defines an annular space  156 . Nozzle barrel member  158  ( FIGS. 3 ,  5 ) has a flange portion  159  that is received within annular space  156  of flanged nut  154 . 
         [0041]    Nozzle barrel member  158  defines a plurality of spray slits  160  for dispersing the fluids in a conical spray configuration or radial fan pattern. In one embodiment, two spray slits  160  are used, each traversing approximately 170° of the outer surface of nozzle barrel member  158 . Greater or fewer spray slits  160  may also be used having a greater or reduced length, as desired. Spray slits  160  are preferably made with a slitting saw. 
         [0042]    In use, a first fluid, e.g., a first polyurea component, is delivered into second passageway  24 ,  124 . The first fluid passes through second passageway  24 ,  124  and into first passageway  22 ,  122  within circumferential passageway  36 ,  136  defined by right plug  32  or mixing cartridge  132 . The first fluid then passes along a length of right plug  32  or mixing cartridge  132  within longitudinal passageway  38 ,  138 , where the first fluid exits a distal end of right plug  32  or from right plurality of quasi-radial passageways  139  within fourth passageway  30 . 
         [0043]    A second fluid, e.g., a second polyurea component, is delivered into third passageway  26 ,  126 . The second fluid passes through third passageway  26 ,  126  and into first passageway  22 ,  122  within circumferential passageway  44 ,  144  defined by left plug  32  or mixing cartridge  132 . The second fluid then passes along a length of left plug  40  or mixing cartridge  132  within longitudinal passageway  46 ,  146 , where the second fluid exits a distal end of left plug  40  of from left plurality of quasi-radial passageways  147  within fourth passageway  30 . 
         [0044]    The first fluid and second fluid impinge upon one another at ring orifice  48  formed by the adjacent distal ends of right plug  32  and left plug  40  or exit from center mixing ports  151 . The first fluid and second fluid mix together to form a fluid disk. 
         [0045]    A third fluid is delivered into center member  50 , i.e., fourth passageway  30 ,  130 . The third fluid passes through fourth passageway  30 ,  130 , where it passes over the fluid disk and carries droplets of the mixed fluids further down fourth passageway  30 ,  130  into nozzle barrel member  58 ,  158 . The mixed fluid then passes through radial orifices  64  and out circumferential spray gap  66  or out of spray slits  160  where the mixed fluids form a conical or radial spray pattern for delivering mixed fluids on an inside surface of a conduit or pipe. 
         [0046]    Referring now to  FIGS. 5 and 6 , shown is an additional embodiment  200  of the mixing apparatus of the invention. Embodiment  200  includes a fluid inlet member  202 . Fluid inlet member  202  has an inlet tube  204  and a body structure  206 . Body structure  206  defines a receiving orifice  208 . As shown in  FIG. 6 , inlet tube  204  communicates with an inside of receiving orifice  208 . 
         [0047]    Nozzle member  210  is received within receiving orifice  208  of fluid inlet member  202 . Nozzle member  210  has a receiving area  212  ( FIG. 5 ) and defines a nozzle barrel  214 . Nozzle barrel  214  defines mixing area  215 . Nozzle barrel  214  defines an inlet orifice  216  ( FIG. 6 ) and a plurality of spray slits  218 . 
         [0048]    Mixing tube  220  has an inlet end  222  ( FIG. 5 ) and an outlet end  224  ( FIG. 6 ). Tip  226  ( FIG. 6 ) extends from outlet end  224 . Outlet end  224  and tip  226  are received within receiving area  212  of nozzle member  210 . Mixing auger  228  is housed within mixing tube  220 . 
         [0049]    In use, a first and a second fluid may be introduced into mixing tube  220  for thorough mixing by mixing auger  228 . A third fluid may be introduced into inlet tube  204  of fluid inlet member  202  for passing through inlet orifice  216  for mixing with the mixed first and second fluids in the mixing area  215 . The mixed first, second and third fluids are then dispersed out of spray slits  218 . 
         [0050]    Referring now to  FIGS. 7-12 , shown is an additional embodiment of a plural component mixing nozzle designated generally  310 . Nozzle  310  is made up of a body  312 , having an inlet side  314 , an exit side  316 , a right side  318  and a left side  320 . Body  312  defines a first passageway  322  that extends from right side  318  to left side  320  of body  312 . 
         [0051]    Body stem  328  extends from exit side  316  of body  312 . Body  312  and body stem  328  define a fourth passageway  330  that passes through body stem  328  and body  312 . Fourth passageway  330  may pass through a narrow portion such as fourth passageway slot  331  ( FIG. 10A ), which directs fluid over dispersing slots  348  of mixing cartridge  349 , which is discussed below. 
         [0052]    Right plug  332  is received in first passageway  322  at right side  318  of body  312 . Right plug  332  has a stem  334  that is co-axial with first passageway  322 . As shown in  FIGS. 7 and 8 , stem  334  of right plug  332  is inserted into first passageway  322 . Right plug  332  defines second passageway  324 . Right inlet member  325  communicates with second passageway  324 . Right tip  327  engages a distal end of right inlet member  325 . Right plug  332  further defines a longitudinal passageway  338  ( FIGS. 7 ,  8 ) that communicates with second passageway  324  at a first end of longitudinal passageway  338  and communicates with a distal end of stem  334  at a second end of longitudinal passageway  338 . 
         [0053]    Left plug  340  is received in first passageway  322  at left side  320  of body  312 . Left plug  340  has a stem  342  that is co-axial with first passageway  322 . Stem  342  of left plug  340  is inserted in first passageway  322 . Left plug  340  defines third passageway  326 . Left inlet member  345  communicates with third passageway  326 . Left tip  347  engages a distal end of left inlet member  345 . Stem  342  of left plug  340  further defines a longitudinal passageway  346 . Longitudinal passageway  346  communicates with second passageway  326  at a first end of longitudinal passageway  346  and communicates with a distal end of stem  342  at a second end of longitudinal passageway  346 . 
         [0054]    When right plug  332  and left plug  340  are installed within first passageway  322 , distal end of stem  334  of right plug  332  and distal end of stem  342  of left plug  340  are located adjacent to an atomizing and blending cartridge, referred to herein as mixing cartridge  349  ( FIGS. 7 ,  8 ,  9 A,  9 B). Mixing cartridge  349  defines dispersing slots  348  for dispersing fluids into fourth passageway  330 . Slots  348  are preferably orientated perpendicular to the axis of cartridge  349 . Slots  348  may be 0.013 ( 1/32) inch wide. 
         [0055]    Mixing cartridge  349  is located in first passageway  322 . Mixing cartridge  349  defines a longitudinal passageway  370  ( FIGS. 7 ,  8 ,  9 A,  9 B) that communicates with an end of longitudinal passageway  338  of right plug  332  and communicates with an end of longitudinal passageway  346  of left plug  340 . Fluids from right longitudinal passageway  338  and left longitudinal passageway  346  are blended when exiting mixing cartridge  349  from slots  348  by high velocity air that atomizes the two fluids during blending. 
         [0056]    Center member  350  engages fourth passageway  330  on inlet side  314  of body  312 . Center member  350  defines a center fluid inlet  352  for delivering a fluid into fourth passageway  330  for flowing past dispersing slots  348 . 
         [0057]    A nozzle sleeve  354  is threadably received on a distal end of body stem  328 . Nozzle sleeve  354  preferably has a tapered outlet end  356 . Nozzle barrel member  358  ( FIGS. 7 ,  8 ,  11 A,  11 B) has a flange member  359  that is received within nozzle sleeve  354 . In one embodiment, nozzle barrel member  358  defines four overlapping slots  364  ( FIGS. 7 ,  8 ,  11 A,  11 B). In a preferred embodiment, four overlapping slots have an overlap of approximately 10 degrees. Emitting a three fluid blend perpendicular to an axis of the nozzle barrel was found to minimize disturbance of the coating as it formed on an interior of a conduit. 
         [0058]    In a further embodiment, nozzle barrel member  360  ( FIGS. 12A ,  12 B) defines a slot or slit  364  that traverses helically about barrel member  360 . Preferably, helix or slot  364  has an approximately 10 degree overlap. Slots  364  may be cut with a 1/32 inch cut mill or, alternatively the barrel member will be molded in plastic. 
         [0059]    In use, a first fluid, e.g., a first polyurea component, is delivered into second passageway  324 . The first fluid passes through second passageway  324  through right longitudinal passageway  338  and into first passageway  327  of body  312  and into longitudinal passageway  370  of mixing cartridge  349 . The first fluid then exits dispersing slots  348  of mixing cartridge  349 . 
         [0060]    A second fluid, e.g., a second polyurea component, is delivered into third passageway  326 . The second fluid passes through third passageway  326  through left longitudinal passageway  346  and into first passageway  346  of body  312  and into longitudinal passageway  370  of mixing cartridge  349 . The second fluid then exits dispersing slots  348  of mixing cartridge  349 . 
         [0061]    The first fluid and second fluid are blended in dispersing slots  348  of mixing cartridge  349 . 
         [0062]    A third fluid is delivered into center fluid inlet  352  of center member  350  for directing fluid into fourth passageway  330 . The third fluid passes through fourth passageway  330 , where it passes over the blend of first and second fluids exiting dispersing slots  348  of mixing cartridge  349 . The third fluid may pass through a narrow portion such as fourth passageway slot  331  to focus the third fluid on the dispersing slots  348  of mixing cartridge  349 . The third fluid carries droplets of the mixed fluids further down fourth passageway  330  into nozzle barrel member  358 ,  360 . The mixed fluid then passes through radial orifices  364  where the mixed fluids form a conical or radial spray pattern for delivering mixed fluids on an inside surface of a conduit or pipe. 
         [0063]    Although the embodiments of the apparatus are described to be used to mix and apply isocyanate and polymer resins forming the compound polyurea, the invention can be used to apply any plural material that reacts to form a compound to ducts and other pipes and tubing. 
         [0064]    Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.