Abstract:
An apparatus and method for transmitting ultrasonic energy. The apparatus may include a vessel, such as a conduit, having a first end, a second end, and a vessel axis between the first and second ends. An ultrasonic energy emitter is positioned toward the first end of the vessel to direct ultrasonic energy into a fluid mixture contained within the vessel. An ultrasonic energy focuser is positioned toward the first end of the vessel proximate to the ultrasonic energy emitter to focus the ultrasonic energy toward the vessel axis as the ultrasonic energy approaches the second end of the vessel. A reflector is positioned toward the second end of the vessel and reflects the ultrasonic energy back toward the ultrasonic energy emitter. A signal reverser redirects at least part of the ultrasonic energy propagating away from the ultrasonic energy emitter.

Description:
RELATED APPLICATIONS 
     This application is related to the following application assigned to a common assignee (a) “Ozone Generator”, application Ser. No. 10/123,759 filed Apr. 15, 2002; (b) Method and Apparatus for Treating Fluid Mixtures with Ultrasonic Energy, application Ser. No. 10/176,728, filed Jun. 20, 2002; (c); Method and Apparatus for Treating Fluid Mixtures with Ultrasonic Energy, application Ser. No. 10/176,334, filed Jun. 19, 2002; (d) and Method and Apparatus for Directing Ultrasonic Energy, application Ser. No. 10/176,333, filed Jun. 19, 2002, which are all herein incorporated by reference. 
    
    
     BACKGROUND 
     1. Field of Invention 
     The present invention relates to methods and apparatuses for directing ultrasonic energy and more particularly to methods and apparatuses for directing ultrasonic energy for treating a fluid mixture contained in a vessel. 
     2. Background of the Invention 
     There are a number of conventional treatment processes for fluid mixtures including fluids including waste water and aqueous mixtures including waste matter. Treatment processes may include filtering, such as reverse osmosis filtering that removes solid contaminants from the waste water or aqueous mixture. However, because of environmental concerns, it may be difficult to dispose of the solid contaminants removed by filters. Furthermore, the filters themselves must be periodically back-flushed, which may be a time consuming process. 
     In an alternate process, microorganisms are disposed in the waste matter to consume or alter harmful elements in the waste matter. However, such systems generally process the waste matter in a batch mode and accordingly may be slow and labor intensive to operate. 
     Another conventional approach is to sterilize waste matter streams with ultraviolet light. One problem with this approach is that the waste matter must be positioned very close to the light source, which may make ultraviolet systems slow, expensive and inefficient. 
     Still another method includes exposing the waste matter stream to ozone which may alter harmful elements in the waste matter stream. One problem with this approach is that the cost of generating effective quantities of ozone historically has been relatively high that the process may not be economically feasible. 
     Another approach has been to dispose a fluid mixture containing a waste matter in a vessel and apply ultrasonic energy to the waste matter in a batch process. Exposing a fluid mixture comprising a fluid mixture to ultrasonic energy may cause chemical and/or physical changes to occur in the fluid mixture. For instance, cavitation of a liquid portion of the fluid mixture and generation of heat. Cavitation bubbles formed in the waste matter stream may grow in a cyclic fashion and ultimately collapse. This process creates very high temperatures, pressures, and thermal cycling rates. For example, it is estimated that this process may develop temperatures in the waste matter stream of up to 5,000 degrees Celsius, pressures of up to 1,000 atmospheres, and heating and cooling rates above 10 billion degrees Celsius per second for durations of less than one microsecond. 
     Apply ultrasonic energy to the waste matter in a batch process suffers from several drawbacks. Batch processing may be relatively slow and the efficiency with which ultrasonic energy is transmitted to waste matter contained in batch may be so low as to leave an unacceptable level of contaminants in the waste matter stream. 
     SUMMARY 
     The present invention is directed toward methods and apparatuses for directing ultrasonic energy for treating a fluid mixture contained in a vessel with the directed ultrasonic energy. 
     In one embodiment of the invention, an apparatus for directing ultrasonic energy includes an ultrasonic energy emitter engaged with a support member. The emitter includes a first surface and a second surface facing opposite the first surface. A signal reverser is positioned adjacent to the second surface of the ultrasonic energy emitter. The signal reverser is biased against but not adhered to the ultrasonic energy emitter. The signal reverser is positioned to receive a portion of ultrasonic energy emitted from the emitter and direct at least part of the portion of ultrasonic energy back towards the emitter. 
     In one embodiment of the invention, an apparatus for a vessel having a first end, a second end opposite the first end, a vessel axis extending between the first and second ends, and a generally straight portion between the first and second ends. The vessel is configured to contain a fluid mixture. The vessel also includes an ultrasonic energy emitter positioned toward the first end of the vessel to direct ultrasonic energy into the fluid mixture during operation. 
     The apparatus may also include an ultrasonic energy focuser positioned toward the first end of the vessel at least proximate to the ultrasonic energy emitter. The focuser may have a focusing surface configured to focus the ultrasonic energy toward the vessel axis as the ultrasonic energy moves toward the second end of the vessel. The focusing surface may include a first portion having a first parabolic shape with a first curvature, and a second portion having a second parabolic shape with a second curvature different than the first curvature. 
     In another aspect of the invention, the apparatus may include an ultrasonic reflector positioned toward the second end of the vessel. The reflector may have a shaped, reflective surface positioned to reflect the ultrasonic energy toward the first end of the vessel. The reflective surface may be curved with an edge at least approximately tangent to a sidewall of the vessel and a tip on, and at least approximately tangent to, an axis spaced apart from the vessel sidewall and extending between the first and second ends of the vessel. 
     In still a further aspect of the invention, the ultrasonic energy emitter may include a first surface facing toward an interior of the vessel and a second surface facing opposite the first surface. The apparatus may further include a signal reverser positioned adjacent to the second surface of the ultrasonic energy emitter. The signal reverser may be biased against, but not adhered to, the ultrasonic energy emitter. The signal reverser is positioned to receive a portion of ultrasonic energy emitted from the emitter and reflect at least part of the portion of ultrasonic energy into the fluid mixture during operation. 
     In yet a further aspect of the invention, the signal reverser may have a third surface adjacent to the second surface of the emitter, a fourth surface opposite the third surface, and a dimension between the third and fourth surfaces of approximately one quarter the wavelength of ultrasonic energy passing into the signal reverser. 
     The invention is also directed toward a method for focusing ultrasonic energy in a fluid mixture. The method includes transmitting ultrasonic energy from an ultrasonic energy emitter into the fluid mixture, impinging the ultrasonic energy on a shaped focusing surface to converge the ultrasonic energy toward a focal point spaced apart from the ultrasonic energy emitter, and exposing a selected constituent of the fluid mixture to the ultrasonic energy as it converges toward the focal point. In another aspect of the invention, the method may be directed toward a method for reflecting ultrasonic energy in a volume of fluid mixture. Accordingly, the method may include transmitting the ultrasonic energy from the ultrasonic energy emitter through the volume of fluid mixture, and impinging the ultrasonic energy on a shaped reflecting surface spaced apart from the ultrasonic emitter to reflect ultrasonic energy back toward the ultrasonic energy emitter. The method may further include exposing a selected constituent of the fluid mixture to the ultrasonic energy as it passes from the ultrasonic energy emitter to the reflecting surface and from the reflecting surface back toward the ultrasonic energy emitter. 
     Exposing a fluid mixture comprising a fluid mixture to ultrasonic energy may cause chemical and/or physical changes to occur in the fluid mixture. Temperatures and pressures developed by the collapsing cavitation bubbles may have several advantageous effects on the constituents of the waste matter stream. For example, the collapsing bubbles may form radicals, such as OH radicals which are unstable and may chemically interact with adjacent constituents in the waste matter stream to change the chemical composition of the adjacent constituents. In one such process, an OH radical reacts with nitrates in the waste matter stream to produce gases such as nitrogen dioxide. The following are sample steps in such a reaction: 
      NO 3   − +.OH_.NO 3 +OH −   [1] 
     
       
         .NO 3   − +.OH_H 2 O.+.NO 2   [2] 
       
     
     
       
         .NO 2 +.NO 2     —   .NO+.NO 3   [3] 
       
     
     
       
         .NO 2 +.NO 2     —   .NO+.NO+O 2   [4] 
       
     
     
       
         .NO 2 +.H_.NO+.OH  [5] 
       
     
     
       
         .NO 2 +.OH_.NO+O 2.   [6] 
       
     
     
       
         .NO 2 +.O._.NO 2 +O 2   [7] 
       
     
     In another embodiment, the reaction may continue, for example, in the presence of additional constituents to produce nitrites. In yet another embodiment, the cavitating bubble may alter trichloroethylene, for example, in accordance with the following simplified reaction: 
     
       
         (Cl) 2 C═CHCl+2H 2 O_ . . . _Cl 2 +HCl+2H 2+ 2CO  [1] 
       
     
     In other embodiments, the collapsing cavitation bubbles may have effects on other molecules that change a chemical composition of the molecules and/or change a phase of the molecules from a liquid or solid phase to a gaseous phase. 
     In still further embodiments, the collapsing cavitation bubbles may have effects on other constituents of the waste matter stream. For example, the combination of increased pressure and cavitation bubbles may disrupt a molecular structure of an organism and accordingly kill pathogenic organisms, such as bacteria. Temperatures and pressures observed in the presence of collapsing cavitation bubbles may serve to alter the structure of living cells and combust or oxidize constituents of the waste matter stream. For example, the high temperature produced by the collapsing cavitation bubble may oxidize constituents of the waste matter stream, producing by-products such as carbon dioxide and ash. The carbon dioxide may evolve from the waste matter stream and the ash may be filtered from the waste matter stream, as will be described in greater detail below. In still another embodiment, the collapsing cavitation bubbles may also separate constituents of the waste matter stream. For example, when the waste matter stream includes a mixture of oil, water, and an emulsifier, the collapsing cavitation bubbles may alter the molecular characteristics of the emulsifier and cause the emulsifier to lose its effectiveness. 
     Accordingly, oil and water may separate from each other and one or the other may be removed from the stream. Collapsing cavitation bubbles may have other effects on the waste matter stream that alter the characteristics of the constituents of the stream in a manner that makes the constituents more benign and/or allows the constituents to be more easily removed from the waste matter stream. In an alternate aspect of the invention, a chemical composition including a selected constituent may be oxidized to produce an ash and a gas. The fluid mixture may be contained under pressure while it is exposed to ultrasonic energy. The treatment vessel may be pneumatically coupled to a vacuum source after being exposed to the ultrasonic energy to remove gas from the fluid mixture. In still a further aspect of the invention, the fluid mixture may be exposed to a first ultrasonic energy having a first energy and a first frequency and the fluid mixture may be exposed to a second ultrasonic energy having a second energy and a second frequency. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A and 1B illustrate ultrasonic energy emitters and signal reversers respectively in accordance with the prior art; 
     FIG. 2 is a partially schematic, isometric view of a processing vessel having ultrasonic energy focusers and ultrasonic energy reflectors in accordance with an embodiment of the invention; 
     FIG. 3 is a partially schematic, cross-sectional side elevation of a portion of the processing vessel shown in FIG. 2; 
     FIG. 4 is a cross-sectional side view of a portion of the processing vessel shown in FIG. 2, including an ultrasonic energy focuser in accordance with an embodiment of the invention; 
     FIG. 5 is an isometric view of an ultrasonic energy reflector in accordance with an embodiment of the invention; 
     FIG. 6 is a cross-sectional, side elevation of the ultrasonic energy reflector shown in FIG. 5 in accordance with an embodiment of the invention; 
     FIG. 7 is a partially schematic, isometric view of an apparatus having several processing vessels in accordance with another embodiment of the invention. 
     FIG. 8 is a partially schematic, cross-sectional view of a portion of a processing vessel having two ultrasonic energy emitters in accordance with another embodiment of the invention. 
     FIG. 9 is a partially schematic, cross-sectional view of a processing vessel for processing waste matter in a batch mode in accordance with another embodiment of the invention. 
    
    
     DETAILED DESCRIPTION 
     The present disclosure describes apparatuses and methods for treating waste matter, such as aqueous waste matter streams. Many specific details of certain embodiments of the invention are set forth in the following description and in FIGS. 2-8 to provide a thorough understanding of these embodiments. One skilled in the art, however, will understand that the present invention may have several additional embodiments, or that the invention may be practiced without several of the details described below. 
     FIG. 2 is a partially schematic, isometric view of processing vessel assembly  110  having ultrasonic energy sources  150  and ultrasonic energy reflectors  130  in accordance with an embodiment of the invention. In one aspect of this embodiment, processing vessel assembly  110  includes a fluid-tight processing vessel  120  formed from a plurality of fluidly connected conduits  121 . A waste matter stream is introduced into processing vessel  120  and exposed to ultrasonic energy emitted by ultrasonic energy sources  150  and reflected by reflectors  130  to reduce or eliminate potentially harmful characteristics of constituents. 
     In one embodiment, processing vessel  120  includes vessel inlet  122  that receives a waste matter stream from a waste matter source, and an vessel outlet  126  that may be coupled to downstream devices. Vessel inlet  122  may be coupled to a manifold  123  that directs the waste matter stream into a plurality of elongated, serially and fluidly connected conduits  121 . Each conduit  121  includes a first end  125   a , a second end  125   b , an inlet  127  and an outlet  128 . The length of each conduit  121  may be proportional to the power of ultrasonic energy source  150  positioned in conduit  121 , and may be approximately 6 feet in one embodiment. Outlet  128  of each conduit  121  is connected to inlet  127  of the next conduit  121  with a riser  124 . Adjacent conduits  121  are supported relative to each other with struts  119 . The waste matter stream proceeds generally from inlet  127  of each conduit  121  to outlet  128 , then through riser  124  to inlet  127  of the next conduit  121 . The waste matter stream passes from the last conduit  121  into vessel outlet  126 . 
     In one embodiment, each conduit  121  includes an ultrasonic energy source  150 , which houses a piezoelectric crystal or another ultrasonic energy emitter or generator and ultrasonic energy reflector  130 . In one aspect of this embodiment, ultrasonic energy source  150  is positioned toward first end  125   a  of conduit  121 , proximate to outlet  128 , and ultrasonic energy reflector  130  is positioned toward second end  125   b  of conduit  121 , proximate to inlet  127 . Accordingly, the waste matter stream travels toward ultrasonic energy sources  150  as it moves through each conduit  121  from inlet  127  to outlet  128 . Alternatively, ultrasonic energy sources  150  is positioned toward second end  125   b  of each conduit  121  with the waste matter stream traveling away from ultrasonic energy sources  150 . In either embodiment, ultrasonic energy reflector  130  is positioned to reflect (a) at least a portion of the ultrasonic energy generated by ultrasonic energy source  150  and/or (b) products produced by the ultrasonic energy, such as cavitation bubbles, back toward ultrasonic energy source  150 , as described in greater detail below with reference to FIG.  3 . 
     FIG. 3 is a partially schematic, cross-sectional side elevation of one of conduits  121  described above with reference to FIG. 2. A fluid stream, for instance a waste matter stream enters conduit  121  through inlet  127  and proceeds through conduit  121  which includes vessel axis  129  to outlet  128 , i.e., from right to left in FIG.  3 . Ultrasonic energy source  150  includes focuser body  160  that focuses ultrasonic energy toward vessel axis  129 , as shown schematically in FIG. 3 by arrows A. Ultrasonic energy reflector  130  includes reflector body  131  towards which the focused ultrasonic energy is directed. Ultrasonic energy reflector  130  reflects the ultrasonic energy back toward ultrasonic energy source  150 , as shown schematically in FIG. 3 by arrows B. In one aspect of this embodiment, reflected energy B is reflected or disposed generally annularly and concentrically around focused energy A. In other embodiments, the relative positions of reflected and focused energies may have other arrangements. In either embodiment, focusing and reflecting the ultrasonic energy may increase the efficiency with which the ultrasonic energy treats the waste matter stream passing through conduit  121 , as described in greater detail below. 
     FIG. 4 is a cross-sectional view of first end  125   a  of conduit  121  and ultrasonic energy source  150  shown in FIG. 3 in accordance with an embodiment of the invention. In one aspect of this embodiment, focuser body  160  of ultrasonic energy source  150  includes emitter support member  162 , such as a flange, that supports ultrasonic emitter  140 , such as a piezoelectric crystal. Focuser body  160  also includes a generally concave focusing surface  161  positioned to receive and focus ultrasonic energy emitted from ultrasonic emitter  140 . Accordingly, focusing surface  161  may be curved to focus ultrasonic energy toward vessel axis  129  and ultrasonic energy reflector  130 , FIG.  3 . In one embodiment, focusing surface  161  may include five segments, shown in FIG. 4 as segments  161   a - 161   e . In a further aspect of this embodiment, each segment  161   a - 161   e  may be defined by a portion of a parabola revolved about vessel axis  129 . Each successive segment  161   a - 161   e  may have an average slope or inclination angle relative to vessel axis  129  that is less than the inclination angle of the preceding segment. 
     Accordingly, the median radius of curvature at the midpoint of successive segments, indicated by arrow “R” for segment  161   e , may increase from segment  161   a  to segment  161   e . For example, in one embodiment, segment  161   a  may have a midpoint radius of about 0.75 inches, segment  161   b  may have a midpoint radius of about 1.7 inches, segment  161   c  may have a midpoint radius of about 2.0 inches, segment  161   d  may have a midpoint radius of about 5.0 inches, and segment  161   e  may have a midpoint radius of about 7.0 inches. Focuser body  160  may be positioned in conduit  121  having a diameter of about 2.75 inches. In other embodiments, segments  161   a - 161   e  may have other midpoint radiuses of curvature and/or conduit  121  may have other diameters. 
     In one aspect of this embodiment, a junction between adjacent segments  161   a - 161   e  may be smoothed or blended to reduce the discontinuity in slope resulting from the change from one parabolic surface to another. Alternatively, the junction may be unsmoothed or unblended. In a further alternate embodiment, focusing surface  161  may include more or fewer segments than are shown in FIG.  4 . In still a further alternate embodiment, focusing surface  161  may include straight segments or segments having curves defined by non-parabolic shapes, so long as focusing surface  161  tends to focus the ultrasonic energy emanating from emitter  140 . Focusing surface  161  may focus energy along vessel axis  129  in one embodiment or, alternatively, along other vessel axes in other embodiments. 
     In one embodiment, ultrasonic emitter  140  may have a first surface  141  facing toward a fluid in conduit  121 , and second surface  142  facing opposite the first surface  141 . Processing vessel assembly  110  may further include an electrically conductive signal reverser  153  having an engaging surface adjacent to second surface  142  of ultrasonic emitter  140 . A first O-ring  152   a  is positioned around ultrasonic emitter  140 , and a second O-ring  152   b  is positioned on a peripheral flange of signal reverser  153 . A contact probe  157  engages signal reverser  153  and is attached to a connector  158 . Connector  158  may be coupled with a coaxial lead  159  to a signal generator  118  to provide electrical power to signal reverser  153 . Signal reverser  153  may then transmit the electrical power to ultrasonic emitter  140  to activate ultrasonic emitter  140 . 
     In a further aspect of this embodiment, ultrasonic energy source  150  may include a retainer ring  154  that threadedly engages internal threads  170  of focuser body  160 . Accordingly, retainer ring  154  may be rotated to engage second O-ring  152   b , which may (a) bias signal reverser  153  against ultrasonic emitter  140  while (b) sealing second O-ring  152   b  against focuser body  160  to protect the electrical connection between signal reverser  153  and probe  157  from exposure to the liquid in conduit  121 . Ultrasonic energy source  150  may further include a plunger  155  that extends through an aperture in the center of retainer ring  154  to contact signal reverser  153 . A cap  156  may threadedly engage external threads  169  of focuser body  160  to bias plunger  155  against signal reverser  153 . In one aspect of this embodiment, plunger  155  may include plastic material, such as Delrin™, and in other embodiments, plunger  155  may include other materials. In either embodiment, plunger  155  may also bias signal reverser  153  against ultrasonic emitter  140 . 
     In one aspect of an embodiment of ultrasonic energy source  150  shown in FIG. 4, ultrasonic emitter  140  and signal reverser  153  may be configured to enhance the efficiency with which ultrasonic energy is transmitted to the fluid within conduit  121 , when compared with some conventional devices. For example, signal reverser  153  may have a thickness “T” that corresponds to about ¼ of the wavelength of the ultrasonic energy transmitted from second surface  142  of ultrasonic emitter  140  into signal reverser  153 . In one specific embodiment in which signal reverser  153  includes copper and ultrasonic emitter  140  is configured to emit ultrasonic energy at a frequency of approximately 980 kHz, signal reverser  153  may have a thickness T of approximately 0.25 inches. When signal reverser  153  includes stainless steel, thickness T may be approximately 0.125 inches for an ultrasonic frequency of about 980 kHz. 
     When signal reverser  153  includes brass, thickness T may be approximately 1.0 inch for an ultrasonic frequency of about 980 kHz. In other embodiments, signal reverser  153  may have other dimensions, depending on the material of signal reverser  153  and the frequency with which ultrasonic emitter  140  emits ultrasonic energy. In any of these embodiments, signal reverser  153  may have a thickness T that corresponds to approximately ¼ of the wavelength of the ultrasonic energy passing through signal reverser  153  from ultrasonic emitter  140 . Accordingly, signal reverser  153  may reflect energy propagating from second surface  142  of ultrasonic emitter  140  back through ultrasonic emitter  140  and into the waste matter in conduit  121 . 
     In another aspect of this embodiment, ultrasonic emitter  140  is not adhesively bonded to signal reverser  153 , unlike some conventional arrangements. Instead, signal reverser  153  is biased against ultrasonic emitter  140  by retainer ring  154  and/or plunger  155 . For example, in one particular embodiment, both retainer ring  154  and cap  156  may be tightened with a torque of from about 10 ft.-lbs. to about 20 ft.-lbs. In other embodiments, signal reverser  153  may be biased against ultrasonic emitter  140  under other torques. An advantage of these embodiments is that it may be easier to control the frequency with which ultrasonic emitter  140  propagates energy into the interior of conduit  121 . It is believed that biasing signal reverser  153  against ultrasonic emitter  140 , rather than gluing or otherwise adhering signal reverser  153  to ultrasonic emitter  140 , may reduce or eliminate the effect of signal reverser  153  on the frequency of ultrasonic energy propagated by ultrasonic emitter  140 . Accordingly, ultrasonic emitter  140  may emit ultrasonic energy at the same or nearly the same frequency as the signal transmitted to it by signal generator  118 . It is believed that this effect is due to the ability of ultrasonic emitter  140  and signal reverser  153  to vibrate with at least some degree of independence relative to each other. 
     In still a further aspect of this embodiment, focuser body  160  may be attached directly to first end  125   a  of conduit  121 . For example, focuser body  160  may include a radially extending washer support surface  163  that engages a washer  164 . A support plate  165  is positioned against washer  164  and both support plate  165  and washer  164  may be clamped against washer support surface  163  with a lock ring  166  that engages external threads  169  of focuser body  160 . Mounting bolts  168  may pass through apertures in washer  164  and support plate  165  to secure focuser body  160  to first end  125   a  of conduit  121 . Processing vessel assembly  110  may further include isolation washers  167  between washer  164  and the end of conduit  121  to electrically isolate focuser body  160  from conduit  121 . In other embodiments, ultrasonic energy source  150  may include other arrangements for attaching focuser body  160  to conduit  121 . 
     FIG. 5 is a side isometric view of reflector body  131  positioned opposite ultrasonic energy source  150 , FIG. 3, in accordance with an embodiment of the invention. In one aspect of this embodiment, reflector body  131  may include a generally concave, curved reflective surface  132  positioned to receive the ultrasonic energy propagating from ultrasonic emitter  140 , FIG. 3, and reflect at least a portion of the ultrasonic energy away from reflector body  131  and toward ultrasonic emitter  140 . In one aspect of this embodiment, reflective surface  132  may be defined by a circular arc revolved about vessel axis  129 . Accordingly, reflective surface  132  may have a tip or cusp portion  134  generally aligned with vessel axis  129 , and a rim portion  135  disposed radially outwardly from tip portion  134 . In other embodiments, reflective surface  132  may have other shapes that receive the impinging ultrasonic energy and reflect the energy back into the waste matter stream. In any of these embodiments, reflective surface  132  may be highly polished, for example, with a micro-finish or a mirror finish to increase the efficiency with which reflective surface  132  reflects ultrasonic energy. 
     FIG. 6 is a cross-sectional side view of reflector body  131  shown in FIG. 5 positioned in a conduit  121  in accordance with an embodiment of the invention. As shown in FIG. 6, rim portion  135  of reflector body  131  may be at least approximately tangent to the walls of conduit  121 . Tip portion  134  may be at least approximately tangent to vessel axis  129  extending through conduit  121 . In a further aspect of this embodiment, reflector body  131  may be secured to conduit  121  with an arrangement of washers, support plates and mounting bolts, not shown in FIG. 6, generally similar to that described above with reference to FIG.  4 . Alternatively, reflector body  131  may be secured to conduit  121  with other arrangements in other embodiments. 
     Operation of an embodiment of processing vessel assembly  110  is described below with reference to FIGS. 2 and 3. Referring first to FIG. 2, a liquid waste matter stream enters processing vessel assembly  110  through vessel inlet  122 , passes serially through each conduit  121 , and exits processing vessel assembly  110  through vessel outlet  126 . Referring now to FIG. 3, the waste matter stream enters each conduit  121  through inlet  127  and flows toward ultrasonic energy source  150  and outlet  128 . Ultrasonic energy source  150  generates ultrasonic energy and introduces the energy into the waste matter stream. Focuser  160  focuses the ultrasonic energy so that it converges toward vessel axis  129  and tip portion  134  of reflector body  131 . In one embodiment, focuser  160  has a shape generally similar to that shown in FIG. 4, conduit  121  has a length of approximately 6 feet and a diameter of approximately 2.75 inches, and the energy converges to a diameter of from about 0.25 inches to about 0.50 inches at tip portion  134 . Reflector  130  reflects the ultrasonic energy back toward ultrasonic energy source  150  with reflected B energy disposed generally annularly around focused energy A. 
     During operation of processing vessel assembly  110 , in accordance with an embodiment of the invention, ultrasonic energy sources  150  emit ultrasonic energy at a power and frequency that cause an aqueous, or other liquid, portion of the waste matter stream to cavitate. A frequency of the ultrasonic energy transmitted by ultrasonic energy sources  150  into the waste matter stream may be selected based on the resonant frequencies of constituents in the waste matter stream. In one particular embodiment, the frequency of ultrasonic energy source  150  may be selected to be at or above a natural resonant frequency of molecules of constituents in the stream. In one further specific example, when the flow includes farm animal fecal waste in an aqueous solution, along with pathogens such as  E. coli , ultrasonic energy sources  150  may be selected to produce a distribution of ultrasonic waves having an energy peak at approximately 980 kilohertz. In other embodiments, the peak energy of ultrasonic energy sources  150  may be selected to occur at other frequencies, depending for example on the types, relative quantities, and/or relative potential harmful effects of constituents in the stream. Accordingly, individual ultrasonic energy sources  150  may be selected to have a particular, and potentially unique, effect on selected constituents of the waste matter stream. 
     In another embodiment, adjacent ultrasonic energy sources within processing vessel assembly  110  may produce different frequencies. For example, ultrasonic energy source  150  in the uppermost conduit  121  of FIG. 2 may emit energy at a higher frequency than that emitted by ultrasonic energy source  150  in the next downstream conduit  121 . An advantage of this arrangement for waste matter streams having multiple constituents, each of which is best affected by ultrasonic energy at a different frequency, is that the waste matter streams may be subjected to a plurality of frequencies, with each frequency tailored to affect a particular constituent of the waste matter stream. Such an arrangement may be more effective than some conventional arrangements for removing constituents from the waste matter stream in a single apparatus. 
     The geometry of processing vessel assembly  110  may be selected to define the time during which any given constituent of the waste matter stream is subjected to the energy emitted by ultrasonic energy sources  150 . For example, the overall length of the flow path through processing vessel assembly  110  and the rate at which the waste matter stream passes through processing vessel assembly  110  may be selected according to the amount of suspended solids in the waste matter stream, with the overall residence time within processing vessel assembly  110  being lower for waste matter streams having relatively few suspended solids and higher for waste matter streams having more suspended solids. 
     One feature of an embodiment of processing vessel assembly  110  described above with reference to FIGS. 2-6 is that focuser  160  and reflector  130  may operate together to reflect energy within conduit  121 . For example, focuser  160  may focus energy toward reflector  130 , and reflector  130  may reflect the energy to travel generally parallel to the walls of conduit  121  back toward focuser  160 . An advantage of this feature is that ultrasonic energy that would otherwise be absorbed by the end walls or the side walls of conduit  121  is instead reintroduced into the flow passing through conduit  121  to increase the likelihood for altering the constituents of the flow. For example, the degree to which bubbles form in conduit  121  has been observed to be greater with the presence of focuser  160  and reflector  130  than without these components, with at least some of the bubbles tending to rise in conduit  121  when subjected to reflected ultrasonic energy. 
     Another feature of an embodiment of processing vessel assembly  110  described above with reference to FIGS. 2-6 is that signal reverser  153  is not adhesively bonded to ultrasonic emitter  140  and is instead biased against ultrasonic emitter  140 . An advantage of this arrangement is that signal reverser  153  may be less likely to alter the frequency of signals emanating from ultrasonic emitter  140 . Another advantage is that ultrasonic emitter  140  may be less likely to overheat than an emitter that is bonded to a signal reflector. Accordingly, an arrangement of ultrasonic emitter  140  and signal reverser  153  in accordance with an embodiment of the invention may have a longer life expectancy than conventional arrangements. 
     Yet another feature of an embodiment of processing vessel assembly  110  described above with reference to FIGS. 2-6 is that signal reverser  153  may have a dimension generally normal to an emitting surface of ultrasonic emitter  140  that corresponds to approximately ¼ of the wavelength of ultrasonic energy passing into signal reverser  153 . Accordingly, signal reverser  153  may more effectively reflect into the waste matter stream a portion of the ultrasonic energy that would otherwise propagate away from the waste matter stream. 
     FIG. 7 is a partially schematic, isometric view of processing apparatus  210  having a plurality of processing vessels  120  in accordance with another embodiment of the invention. In one aspect of this embodiment, processing vessel  120  is coupled to a common supply manifold  202 . In a further aspect of this embodiment, each processing vessel  120  includes a selector valve  204  at a junction with supply manifold  202 . Accordingly, incoming waste matter may be selectively directed into one or more of processing vessels  120 . In a further aspect of this embodiment, each processing vessel  120  may be configured to process a particular type of waste matter stream, for example, by including ultrasonic energy sources tuned to a particular ultrasonic frequency. Accordingly, the incoming waste matter stream may be selectively directed to a selected processing vessel  120  configured to best interact with the constituents of that waste matter stream. 
     FIG. 8 is a partially schematic, cross-sectional side elevation of a portion of processing vessel assembly  310  that includes a conduit  121  having an inlet  127  and an outlet  128  arranged in a manner generally similar to that of processing vessel assembly  110  described above with reference to FIG.  2 . In one aspect of this embodiment, processing vessel assembly  310  includes two ultrasonic energy sources  150  positioned at opposite ends of conduit  121 . Each ultrasonic energy source  150  includes an ultrasonic energy emitter  140  generally similar to those described above with reference to FIGS. 2-7. Accordingly, processing vessel assembly  310  may increase the amount of ultrasonic energy introduced to the waste matter stream passing through conduit  121  compared with conventional devices having a single ultrasonic energy source. Conversely, an advantage of a device having an ultrasonic focuser and reflector generally similar to those described above with reference to FIGS. 2-6 is that the reflected ultrasonic energy may be reflected around the energy emitted from ultrasonic emitter  140  to impinge on focuser  160 , rather than directly on ultrasonic emitter  140 . Accordingly, ultrasonic emitter  140  may be less subject to long-term wear than ultrasonic energy sources  150  shown in FIG.  8 . 
     FIG. 9 is a partially schematic, cross-sectional view of processing vessel assembly  410  configured to process waste matter in a batch mode in accordance with another embodiment of the invention. In one aspect of this embodiment, processing vessel assembly  410  includes vessel  420  having an ultrasonic energy source  450  and focuser  460  at one end, and ultrasonic energy reflector  430  at an opposite end. A fluid may be introduced to vessel  420  through inlet/outlet  411  and subjected to ultrasonic energy in a manner generally similar to that described above with reference to FIGS. 2-6. After a selected period of time, the fluid may be removed through inlet/outlet  411 . 
     In an alternative arrangement, processing vessel assembly  410  includes two ultrasonic energy sources  450 , one at each end of vessel  420 , in a manner generally similar to that described above with reference to FIG.  8 . 
     From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. For example, in one alternate embodiment, the apparatus may include a support member that supports the ultrasonic energy emitter, but does not have a focusing surface. The apparatus may include a reflector and/or a signal reverser arranged in a manner generally similar to one or more of the embodiments described above with reference to FIGS. 2-9. Accordingly, the invention is not limited except as by the appended claims.