Abstract:
A fluid mixing apparatus and method include a first fluid assembly having at least one fluid nozzle for providing a first fluid; a second fluid assembly having at least one fluid mixing nozzle sized and shaped to be received by the at least one fluid nozzle for providing a second fluid into the first fluid; a mixing region disposed where the at least one fluid nozzle and the at least one fluid mixing nozzle coact in spaced relationship for providing turbulence to the first and second fluids, thereby providing a fluid mixture thereof; and a passageway in communication with the mixing region for expanding the fluid mixture into a different phase.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to nozzle assemblies such as for example CO 2  spray nozzle assemblies. 
         [0002]    Single point and broad spray nozzles are fabricated with a plurality of welded sections. Broad spray nozzles are fabricated from an orifice array tube and a barrel block machined to accept the plurality of the nozzles. It is unacceptable to industry if a single nozzle in a broad spray nozzle array does not perform to specification. This sometimes occurs because the broad spray nozzle could not be properly cleaned due to areas and regions in the nozzle created by the manufacturing process. These areas and regions trap materials which could contaminate the purity of CO 2  fluid being dispensed through such nozzle. Therefore, welding together separate and discreet nozzles or nozzle assemblies can provide for these areas and regions determined to be unacceptable by industry. 
         [0003]    In addition, injection of different fluids, such as gases for such applications as surface charge mitigation, is not possible with existing nozzles and nozzle arrays because such nozzles or nozzle arrays do not permit for admixing different fluids above their solubility levels, i.e. the mixtures end up separating out into their original distinct fluids or do not mix sufficiently so that the user is left with two separate fluids for treatment, as opposed to a blended or homogenous mixture for treatment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    For a more complete understanding of embodiments of the invention, reference may be had to the following detailed description taken in conjunction with the Figures, of which: 
           [0005]      FIG. 1  is a cross-section of elements of an embodiment of a fluid injection assembly of the present invention. 
           [0006]      FIG. 2  is a cross-section along line  2 - 2  of  FIG. 1 . 
           [0007]      FIG. 3  is a partial-cross section of a nozzle array embodiment of the present invention. 
           [0008]      FIG. 4  is a partial cross-section of another embodiment of the invention. 
           [0009]      FIG. 5  is an exploded view of a portion of the embodiment shown in  FIG. 4 . 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0010]    The inventive embodiments include placement of a fluid mixing assembly at a point of CO 2  fluid or snow generation, thereby allowing the ratio of fluids to be greater than can be achieved by mere dilution of one fluid into another fluid. The embodiments provide electro-static discharge (ESD) mitigation and the addition of co-solvent cleaning agents to the CO 2  snow. 
         [0011]    The inventive embodiments provide a nozzle assembly in which spray performance testing of single and multiple nozzle arrays can be conducted prior to full assembly of the nozzle array. Precision cleaning of all components prior to full assembly of the nozzle and nozzle array is also facilitated with the invention. In addition, the manufacturing process to produce the nozzle and nozzle array does not provide hidden regions or zones where contaminant material can be trapped. Full micropolishing of all components of the nozzle and nozzle array is realized by the present embodiments. Moreover, direct injection of other fluids (liquids or gases) into the spray nozzle or nozzle array to help control surface charging is also provided by the invention. 
         [0012]    Referring to  FIGS. 1 and 2 , a nozzle is shown generally at  10 . The nozzle includes a cylindrical housing  12  having formed therein a receiving chamber  14  and a distribution chamber  16  in communication with the receiving chamber  14  at a passageway  18 . The passageway  18  interconnents the receiving chamber  14  and the distribution chamber  16 . The passageway  18  has a diameter less than a diameter of the receiving chamber  14  and the distribution chamber  16 . 
         [0013]    The receiving chamber  14  is constructed and arranged to receive a pipette  20  or tube for injection of a fluid. This arrangement and coaction will be described further with reference below to  FIG. 5 . The pipette  20  has an exterior sidewall  22  sized and shaped for permitting the pipette  20  to slide into position within the receiving chamber  14  without the pipette  20  contacting an interior surface of the housing  12  at the receiving chamber  14 . Supports  24  (support means) or “spiders” for example as shown in  FIG. 2  support the pipette  20  away from contact or in spaced relation with an interior surface  19  of the receiving chamber  14 . The supports  24  may be protruding members spaced apart to support the pipette  20 , but not impede the flow of fluid in the chamber  14 . 
         [0014]      FIG. 3  shows a plurality of the nozzles  10  mounted to a distribution manifold  26 , which manifold  26  has an end  28  connected to a CO 2  source (not shown). An opposed end  30  of the distribution manifold  26  may be closed or sealed, or alternatively connected to a storage vessel (not shown) or other application system (not shown). Each of the nozzles  10  in the array may be individually tested before being inserted into the manifold  26 . Each nozzle  10  is inserted into the manifold  26  and tact-welded for example. For removal, the weld(s) may be broken to free the nozzle  10  after which it can be repaired, thereby obviating the necessity to designate the nozzle  10  as scrap. 
         [0015]    The manifold  26  includes a manifold passageway  32  extending to connect the ends  28 ,  30  of the manifold  26 . The passageway  32  includes at least one and where necessary a plurality of branches  34  extending therefrom. The branches  34  may be spaced apart to permit a plurality of nozzles  10  to be mounted in registration with the branches  34 , as shown in  FIG. 3 . As also shown in  FIG. 3 , fluid  17  will flow from the passageway  32  to each of the branches  34 . 
         [0016]      FIG. 4  shows the distribution manifold  26  of  FIG. 3  and a fluid injection manifold  36  used in association therewith. As shown in  FIG. 4 , the fluid injection manifold  36  has a plurality of the pipettes  20  or nozzles sized and shaped for any of releasable engagement, permanent mounting, or removable disposition with respect to corresponding branches  34  and nozzles  10  of the distribution manifold  26 . An end  40  of the fluid injection manifold  36  is connected to a source (not shown) of for example an electrostatic discharge fluid  41  for cleaning enhancement, while an opposed end  42  of the fluid injection manifold  36  may be closed or sealed, or alternatively connected to a collection source (not shown) for such fluid or other application system (not shown). 
         [0017]    In  FIG. 4 , the manifold  26  is formed with at least one and where necessary a plurality of bores  48  sized and shaped so that each one of the bores  48  can receive a corresponding one of the pipettes  20  therein. The bores  48  are in turn in registration with the passageways  34 , thereby permitting the pipettes  20  to extend through to the receiving chambers  14 . The distance that the pipettes  20  extend into the passageways  34  and receiving chambers  14  is dependant on the viscosity of the fluid being provided to the fluid  17 , which can vary greatly in CO 2  with slight temperature changes. The distance is determined after the nozzle  10  is started on CO 2  and chills down to the operating temperature for a particular application. 
         [0018]    The fluid in either of gas or liquid phase provided to the distribution manifold  26  can include carbon dioxide from the CO 2  source; while nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon, hydrogen, helium, ozone or combinations thereof can be provided from the manifold  36 , which is connected to a supply therefore. These fluids may be supplied individually or perhaps in combination with each other where such combination would not be detrimental to the process. The fluid injection manifold  36  may also provide water, ozonated water, and other species produced to include but not limited to halides, corrosives, acids, bases, oxidizers or peroxides. The percentages or proportions of the fluids injected are selected to be in a proportion sufficient for a particular cleaning or other treatment process of the component. 
         [0019]    An introduction of such fluids by the injection manifold  36  substantially reduces if not eliminates unwanted surface charging which may occur when CO 2  gas is provided from the nozzles  10  to surfaces of objects (not shown) to be cleaned. 
         [0020]    The pipettes  20  may be manufactured for removable mounting with respect to the receiving chambers  14 . 
         [0021]    A mixing region of the embodiments of the invention is shown generally at  44  in  FIGS. 4 and 5 . Referring to  FIG. 5 , the mixing region  44  is a region where fluid shown by arrows  21  in the pipette  20  contacts the fluid shown by arrows  17  in the receiving chamber(s)  14  to create turbulence shown generally at  38 , whereby the fluids  17 ,  21  are mixed for transit through the passageway  18  to the distribution chamber  16  for application to the object or component being cleaned or otherwise treated. 
         [0022]    In the receiving chamber  14 , the fluids  17 ,  21  can be mixed at concentrations wherein the fluid  17  is at a concentration of 0.001 to 0.1 parts per unit volume of the fluid  21 , as needed by the cleaning application required or surface treatment necessary. Concentrations above  0 . 1  may be used in applications where a plurality of the second fluids  17  are added simultaneously to mitigate surface charging and enhance cleaning of an object or component to be treated. The arrangement of the pipette  20  with respect to the receiving chamber  14  to provide turbulence  38  enables the fluids  17 ,  21  to be mixed above their solubility levels. That is, because of the turbulence  38  created in the mixing region  44 , the fluids  17 ,  21  are thoroughly blended or provided as a homogenous mixture, even though the fluids  17 ,  21  are mixed above their solubility levels. The turbulence  38  provided as a result of the construct of the embodiments of the invention, enables greater proportions of each of the fluids  17 ,  21  to be used with respect to each other for mixing, and still provide for a blended or homogenous mixture to transit the passageway  18  for distribution from the distribution chamber  16  to the component. In effect, a user can include a greater percentage by volume of the fluid  21  to be mixed with the fluid  17 , or greater percentage by volume of the fluid  17  to be mixed with the fluid  21 , and not have the resulting mixture or blend segregate out into the separate fluids that existed prior to being mixed in the mixing region  44 . The embodiments of the invention provide a solid phase mixture, with perhaps some gas of the fluids  17 ,  21 , which emerges from the distribution chamber  16 . 
         [0023]    The lesser diameter of the passageway  18  prevents the fluids  17 ,  21  in the turbulence  38  from shifting to a solid phase prior to entering the distribution chamber  16 . Where the fluid  17  is for example CO 2 , such fluid must be mixed in the chamber  14  at the turbulence  38  while still in the fluid phase. CO 2  in the mixture will expand after the passageway  18  and enter a solid phase, where mixing with the fluid  21  is ineffective and insufficient. 
         [0024]    As shown in  FIG. 5 , in one embodiment the disposition of the pipette  20  with respect to the nozzle  10  is such that both are coaxially arranged with respect to each other. In effect, a longitudinal axis of the pipette  20  and the nozzle  10  are coaxial, represented at “X”, so that when the nozzle  20  is disposed in the chamber  14  it is in registration and coaxial with the nozzle  10  such that an outlet  23  of the pipette  20  is in registration with the passageway  18 . 
         [0025]    Depending upon the fluid  21  to be mixed with the fluid  17 , and vice versa, such will determine the solubility limits of the resulting mixture which occurs at the region of turbulence  38 . For example, with the fluid  17  being carbon dioxide (CO 2 ), such a fluid can be admixed with greater than 0.05% acetone, if acetone is the fluid  21  being used. The resulting mixture or blend for distribution from the distribution chamber  16  can be applied to the object being cleaned or treated, and such mixture will have the solubility percentage of at least one of the fluids  17 ,  21  beyond that which would normally be available with conventional mixing systems. In certain embodiments, both of the fluids  17 ,  21  are mixed above their solubility levels with respect to each other. A depth to which the pipette  20  is inserted into the mixing chamber and the distance of which an exterior surface of the pipette  20  is spaced apart from an interior sidewall of the nozzle  10  at the mixing chamber  14  may also be selected depending upon the fluid  17 ,  21  being brought together for mixing in the mixing region  44 . 
         [0026]    A distal end  25  of a sidewall  27  for the pipette  20  in  FIG. 5  is cut-back or tapered at from a minimum of 0.001 inches to a maximum of 0.025 inches. This tapering of the distal end  25  is to facilitate directing the fluid  17  to the turbulence  38 , and to facilitate the fluid  21  being drawn into the fluid  17 . The taper at the distal end  25  also provides for a sufficient lower pressure proximate the distal end  25  to draw the fluid  21  into the turbulence  38  to mix with the fluid  17 . 
         [0027]    The pipette  20  may also be arranged non-concentrically with respect to the longitudinal axis X so that it is out of registration with the longitudinal axis X of the passageway  18  and the distribution chamber  16 . Such an arrangement of the pipette  20  may be called for where the resulting mixture does not need to be as thoroughly blended in the mixing region  44  depending of course upon the treatment or cleaning that is to occur by the fluid discharged from the distribution chamber  16 . 
         [0028]    It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as described and claimed herein. It should be understood that the embodiments described above are not only in the alternative, but may be combined.