Patent Abstract:
A suspension processing method using ultrasonic waves has problems in that movement of solids in liquid do not follow movement of the sound field. Accordingly, application to a field that requires a high suspension processing performance or a high flow rate process is difficult. In order to achieve the high suspension processing performance, a design of adopting a long and large oscillator and the like is required. A suspension processing device ( 30 ) of separating and concentrating a component of solids in suspension ( 1   a ) using ultrasonic waves, includes: at least one supply port ( 32 ) for supplying the suspension ( 1   a ) into the device; a channel ( 31 ) through which the suspension flows; at least two outlet ports ( 33  and  34 ) for discharging processed suspension ( 1   a ); an oscillator ( 35 ) for emitting ultrasonic waves; and a reflection plate ( 36 ) for reflecting the emitted ultrasonic waves.

Full Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a suspension processing device using ultrasonic waves. 
       BACKGROUND ART 
       [0002]    The background arts in this technical field include Japanese Patent No. 2723182 Publication (Patent Literature 1). This publication describes “for capturing fine objects in a liquid medium by aligning them at half-wave length intervals at nodes of sound pressure in a standing wave sound field, a back electrode of an ultrasonic oscillator is made of multiple strip electrode pieces independently arranged parallel with each other, and such an electrode piece to which voltage is applied is electrically switched to an adjacent electrode piece to move a driving part of the ultrasonic oscillator and move the standing wave sound field, thereby moving the captured fine objects along the arrangement direction of the electrode pieces.” (see Abstract). 
         [0003]    The arts also include Japanese Patent Laid-Open Publication No. 2004-24959 (Patent Literature 2). This publication describes “an ultrasonic noncontact filtering method and apparatus therefor where a ultrasonic oscillator and a reflection plate are arranged in parallel with each other in and along a flow path filled with a liquid medium, emitted ultrasonic waves are reflected by the reflection plate, and fine objects dispersed in the liquid medium are captured at nodes of sound pressure or antinodes of the sound pressure of a standing wave sound field generated in the flow path” (see Abstract). 
       CITATION LIST 
     Patent Literature 
       [0004]    Patent Literature 1: Japanese Patent Publication No. 2723182 
         [0005]    Patent Literature 2: Japanese Patent Laid-Open Publication No. 2004-24959 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    Patent Literature 1 describes a method of concentrating and filtering fine particles in suspension using ultrasonic waves oscillated by a rectangular oscillator including multiple electrodes (hereinafter, the foregoing method is described as a suspension processing method). However, the suspension processing method of Patent Literature 1 has problems in that movement of solids in liquid do not follow movement of the sound field. Accordingly, application to a field that requires a high processing performance (a performance of concentrating suspension and a clearing performance) or a high flow rate process is difficult. 
         [0007]    Furthermore, as described in Patent Literature 2, even with a single oscillator, modulation of an input signal can concentrate and separate solids in liquid. However, the oscillator is arranged parallel to the flow of liquid to be processed. Accordingly, the solids are transported during processes. In order to achieve a high processing performance, a design of configuring a long or large oscillator is required. 
         [0008]    The present invention thus provides a suspension processing device that achieves a high processing performance without need to enlarge the oscillator. 
       Solution to Problem 
       [0009]    In order to solve the problems, for instance, configurations according to Claims are adopted. 
         [0010]    The present application includes multiple solutions to the problems. One example of the solutions may be a suspension processing device using ultrasonic waves, the device including: an oscillator and a reflection plate in and orthogonal to a flow path filled with a liquid medium; and an outlet port in the flow path sandwiched by the oscillator and the reflection plate. 
       Advantageous Effect of Invention 
       [0011]    The present invention enables a suspension processing device using ultrasonic waves to have a high suspension processing performance without enlarging the oscillator. Problems, configurations and advantageous effects other than those described above are apparent through description of the following embodiments. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  shows an example of a process configuration diagram in the case of using a suspension processing device using ultrasonic waves. 
           [0013]      FIG. 2  is a configuration diagram of a suspension processing device of Embodiment 1 using ultrasonic waves. 
           [0014]      FIG. 3  is a diagram illustrating a suspension processing device using ultrasonic waves. 
           [0015]      FIG. 4  is a diagram showing a result of Embodiment 1. 
           [0016]      FIG. 5A  is a diagram of comparison between clear liquid turbidities before and after the process of Embodiment 1. 
           [0017]      FIG. 5B  is a diagram of comparison between concentrate liquid turbidities before and after the process of Embodiment 1. 
           [0018]      FIG. 6  is a configuration diagram of a suspension processing device of Embodiment 2 using ultrasonic waves. 
           [0019]      FIG. 7  shows an example of a process configuration diagram in the case of using a suspension processing device using ultrasonic waves. 
           [0020]      FIG. 8A  is a plan view of an oscillator in a suspension processing device of Embodiment 3 using ultrasonic waves. 
           [0021]      FIG. 8B  is a configuration diagram of the suspension processing device of Embodiment 3 using ultrasonic waves. 
           [0022]      FIG. 9  is a diagram illustrating a suspension processing device using ultrasonic waves. 
           [0023]      FIG. 10  is a diagram showing a result of Embodiment 3. 
           [0024]      FIG. 11  is a configuration diagram of a suspension processing device of Embodiment 4 using ultrasonic waves. 
           [0025]      FIG. 12A  is a configuration diagram of a suspension processing device of Embodiment 5 using ultrasonic waves. 
           [0026]      FIG. 12B  is an arrangement diagram of a supply port in the suspension processing device of Embodiment 5 using ultrasonic waves. 
           [0027]      FIG. 12C  is a diagram showing a swirl flow in the suspension processing device of Embodiment 5 using ultrasonic waves. 
           [0028]      FIG. 13A  is a plan view of an oscillator in a suspension processing device of Embodiment 6 using ultrasonic waves. 
           [0029]      FIG. 13B  is a configuration diagram of the suspension processing device of Embodiment 6 using ultrasonic waves. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0030]    Embodiments are hereinafter described using the drawings. 
       EMBODIMENTS 
     Embodiment 1  
       [0031]    In this embodiment, an example of a suspension processing device using ultrasonic waves is described. 
       (Configuration of Suspension Processing Device) 
       [0032]      FIG. 1  shows an example of a process configuration in the case of using the suspension processing device using ultrasonic waves. 
         [0033]      FIG. 2  is a configuration diagram of the suspension processing device using ultrasonic waves. 
         [0034]    A tank  10  is filled with suspension  1   a.  The tank  10  communicates with a pump  20  through a liquid feeding tube  61 . The suspension  1   a  fed to the pump  20  through the liquid feeding tube  61  passes through a liquid feeding tube  62 , and is supplied to the suspension processing device  30 . 
         [0035]    As shown in  FIG. 2 , the suspension processing device  30  includes a channel  31 , a supply port  32  that communicates with the liquid feeding tube  62 , an outlet port  33  that communicates with a liquid feeding tube  63 , a concentrate port  34  that communicates with a liquid feeding tube  64 , an oscillator  35  that generates ultrasonic waves, and a reflection plate  36  that reflects ultrasonic waves. 
         [0036]    The supply port  32  is arranged upward at an upstream end of the channel  31  such that the flow directions of the suspension  1   a  in the liquid feeding tube  62  and the channel  31  are different from each other. The outlet port  33  is arranged upward at a downstream end of the channel such that the flow directions of the suspension  1   a  in the liquid feeding tube  63  and the channel  31  are different from each other. The oscillator  35  and the reflection plate  36  at the opposite ends on the upstream side and the downstream side so as to sandwich the channel  31  of the suspension processing device  30 . The oscillator  35  has an oscillating surface arranged so as to emit ultrasonic waves to the suspension in the channel  31 . 
         [0037]    The concentrate port  34  is disposed downward at the channel  31  between the supply port  32  and the outlet port  33 . The outlet port  33  communicates with the liquid feeding tube  63 . The liquid having passed through the liquid feeding tube  63  is discharged into a tank  50  in  FIG. 1 . The concentrate port  34  communicates with the liquid feeding tube  64 . The liquid having passed through the liquid feeding tube  64  is discharged into a tank  40  in  FIG. 1 . The suspension  1   a,  supplied from the supply port  32  to the channel  31 , passes through this channel  31  and is then discharged to the outside of the suspension processing device  30  from the outlet port  33  or the concentrate port  34 . 
       (Operation/Process) 
       [0038]      FIG. 3  is a diagram for illustrating an operation principle. 
         [0039]    The oscillator  35  and the reflection plate  36  are thus arranged opposite to each other so as to sandwich the channel  31 , and ultrasonic waves are emitted into the channel  31 , thereby forming a standing wave in the channel  31 . Accordingly, regions with high sound pressure (nodes) and regions with low sound pressure (antinodes) cyclically appear along the channel  31 . 
         [0040]    At this time, if liquid that fills the channel  31  contains solids sufficiently small in comparison with the intervals between antinodes and nodes (hereinafter, referred to as solids), the solids receive forces toward the nodes or antinodes according to the physical property values of the solids and are captured at the positions of antinodes or nodes in the channel  31 . 
         [0041]    The captured solids can be transported in the channel  31  in the direction from the oscillator  35  to the reflection plate  36  or from the reflection plate  36  to the oscillator  35  by modulating ultrasonic waves. 
         [0042]    The captured solids flocculate during transportation. Accordingly, when the solids are grown to have a certain size, the floccules settle to the bottom of the channel  31  by their own weights. The position of settling of flocculated solids depends on the flow velocity of the suspension  1   a  flowing in the channel  31  and the modulation speed of ultrasonic waves. The concentrate port  34  is thus provided around the settling position, thereby allowing most of solids having settled by their own weights to be selectively collected. 
         [0043]    As described above, the suspension  1  a supplied to the channel  31  passes through this channel  31 , to which the ultrasonic waves are emitted, thereby enabling the suspension to be separated into clear liquid  5   a  with a small number of solids in the liquid and concentrate liquid  4   a  with a large number of solids in the liquid and then collected. Here, the transport direction of the captured solids and the flowing direction of the liquid in the channel  31  are configured opposite to each other. This configuration can prevent the captured solids from flowing to the downstream. Accordingly, separation and concentration performances can be improved. The clear liquid  5   a  passes through the outlet port  33  and the liquid feeding tube  63  and is discharged into the tank  50 . The concentrate liquid  4   a  passes through the concentrate port  34  and the liquid feeding tube  64  and is discharged into the tank  40 . 
       Advantageous Effects 
       [0044]    Advantageous effects (processing performance) in the case of using the suspension processing device are described below. The processing performance of the suspension processing device is evaluated with reference to the turbidity of sample liquid discharged from the outlet port  33  and the concentrate port  34 . The adopted sample liquid and output conditions of ultrasonic waves are as follows. 
         [0000]    (1) Sample liquid: suspension that contains pure water and alumina particles having an average particle diameter of 15 micrometers dispersed therein (average turbidity: 17.3 degrees). 
         [0045]    (2) Ultrasonic waves: a sinusoidal wave having frequencies from 2 to 3 MHz modulated at five-second intervals is generated by a function generator, amplified by a power amplifier and input into the oscillator  35 . 
         [0046]      FIGS. 4 ,  5 A and  5 B show processing results of the sample liquid by the suspension processing device in  FIG. 2 .  FIG. 4  shows a relationship between the distance of the concentrate port  34  from the oscillator  35  and the turbidity of suspension discharged from the concentrate port  34 . As shown in  FIG. 4 , in the case of disposing the concentrate port  34  at a position of a distance of 60 mm from the oscillator  35 , the turbidity of suspension discharged from the concentrate port  34  is higher than an initial turbidity (17.3 degrees). Solids in the liquid are thus concentrated and discharged. 
         [0047]      FIGS. 5A and 5B  show processing results of the sample liquid by the suspension processing device in  FIG. 2 .  FIGS. 5A and 5B  show change in the respective turbidities of the sample liquid discharged from the outlet port  33  and the sample liquid discharged from the concentrate port  34 . 
         [0048]    In the case where the turbidity of the sample liquid supplied to the suspension processing device is 17.3 degrees (equivalent to the turbidity of sports drink), the turbidity of the sample liquid discharged from the outlet port  33  is reduced to 1.2 degrees (guideline value for tap water&lt;2 degrees), while the turbidity of the sample liquid discharged from the concentrate port  34  is increased to 19.4 degrees. The above evaluation result suggests that the number of alumina particles in the sample liquid discharged from the outlet port  33  decreases from that before the process while the number of alumina particles in the sample liquid discharged from the concentrate port  34  increases from that before the process. Such use of the suspension processing device in  FIG. 2  can separate the suspension into clear liquid (liquid discharged from the outlet port  33 ) having a small solids component and concentrate liquid (liquid discharged from the concentrate port  34 ) having a concentrated solids component. 
       Embodiment 2  
       [0049]    In this embodiment, an example of a suspension processing device of Embodiment 2 using ultrasonic waves is described. 
       (Configuration of Suspension Processing Device) 
       [0050]      FIG. 6  is a configuration diagram of a suspension processing device using ultrasonic waves. 
         [0051]    The suspension processing device  30  includes a channel  31 , a supply port  32  that communicates with a liquid feeding tube  62 , an outlet port  33  that communicates with a liquid feeding tube  63 , a concentrate port  34  that communicates with a liquid feeding tube  64 , an oscillator  35  that generates ultrasonic waves, and a reflection plate  36  that reflects ultrasonic waves. 
         [0052]    The supply port  32  is arranged upward at an upstream end of the channel  31  such that the flow directions of the suspension  1   a  in the liquid feeding tube  62  and the channel  31  are different from each other. The outlet port  33  is arranged downward at a downstream end of the channel such that the flow directions of the suspension  1   a  in the liquid feeding tube  63  and the channel  31  are different from each other. The oscillator  35  and the reflection plate  36  are arranged at opposite ends of the channel  31  of the suspension processing device  30  on the upstream side and the downstream side so as to sandwich this channel. The concentrate port  34  is disposed upward at the channel  31  between the supply port  32  and the outlet port  33 . 
       (Operation/Process/Advantageous Effect) 
       [0053]    The oscillator  35  and the reflection plate  36  are thus arranged parallel to each other so as to sandwich the channel  31 , and ultrasonic waves are emitted into the channel  31 , thereby forming a standing wave in the channel  31 . Accordingly, regions with high sound pressure (nodes) and regions with low sound pressure (antinodes) cyclically appear along the channel  31 . 
         [0054]    At this time, in the case where the channel  31  is filled with emulsion that contains droplets and a parent phase and the droplets are sufficiently small with respect to the intervals between antinodes and nodes, the droplets receive forces toward the antinodes or nodes according to the physical property values of the droplets and are then captured at the positions of antinodes or nodes in the channel  31 . The captured droplets can be transported in the channel  31  in the direction from the oscillator  35  to the reflection plate  36  or from the reflection plate  36  to the oscillator  35  by modulating ultrasonic waves. 
         [0055]    The captured droplets flocculate during transportation. If the droplets have smaller densities than the parent phase has, the flocculated droplets float upward. The floating position depends on the flow velocity in the channel  31  and the modulation speed of ultrasonic waves. The concentrate port  34  is thus provided around the floating position, thereby allowing most of floating droplets to be selectively collected. 
       Embodiment 3  
       [0056]    In this embodiment, an example of a suspension processing device of Embodiment 3 using ultrasonic waves is described. 
       (Configuration of Suspension Processing Device) 
       [0057]      FIG. 7  shows an example of a process configuration in the case of using a suspension processing device using ultrasonic waves. 
         [0058]      FIGS. 8A and 8B  are configuration diagrams of the suspension processing device using ultrasonic waves. 
         [0059]    A tank  10  is filled with suspension  1   a.  The tank  10  communicates with a pump  20  through a liquid feeding tube  61 . The suspension  1   a  fed to the pump  20  through the liquid feeding tube  61  passes through a liquid feeding tube  62 , and is supplied to the suspension processing device  30 . 
         [0060]    As shown in  FIG. 8B , the suspension processing device  30  includes a channel  31 , a supply port  32  that communicates with the liquid feeding tube  62 , an outlet port  33  that communicates with a liquid feeding tube  63 , a concentrate port  34  that communicates with a liquid feeding tube  64 , an oscillator  35  that generates ultrasonic waves, and a reflection plate  36  that reflects ultrasonic waves, and is arranged such that an end of the channel at which the oscillator  35  is disposed is oriented upward. 
         [0061]    The oscillator  35  and the reflection plate  36  are arranged at opposite ends of the channel  31  of the suspension processing device  30  so as to sandwich this channel in the longitudinal axis direction. The oscillator  35  is arranged such that an oscillating surface is oriented downward to emit ultrasonic waves to the suspension in the channel  31 . 
         [0062]    As shown in  FIG. 8A , the oscillator  35  has an opening on the surface. The outlet port  33  is arranged directly above the opening, and communicates with the liquid feeding tube  63 . Liquid having passed through the liquid feeding tube  63  is discharged into a tank  50  shown in  FIG. 7 . The concentrate port  34  is disposed sideways at an end of the channel  31  nearer to the reflection plate  36 . The concentrate port  34  communicates with the liquid feeding tube  64 . The liquid having passed through the liquid feeding tube  64  is discharged into a tank  40  in  FIG. 7 . 
         [0063]    The supply port  32  is disposed sideways on the surface of the channel  31  between the oscillator  35  and the reflection plate  36 , and communicates with the liquid feeding tube  62 . The suspension  1   a,  supplied from the supply port  32  to the channel  31 , passes through this channel  31  and is then discharged to the outside of the suspension processing device  30  from the outlet port  33  or the concentrate port  34 . 
       (Operation/Process) 
       [0064]      FIG. 9  is a diagram for illustrating an operation principle. 
         [0065]    The oscillator  35  and the reflection plate  36  are thus arranged so as to sandwich the channel  31  in the longitudinal axis direction, and ultrasonic waves are emitted into the channel  31 , thereby forming a standing wave in the channel  31 . Accordingly, regions with high sound pressure (nodes) and regions with low sound pressure (antinodes) cyclically appear along the channel  31 . 
         [0066]    At this time, if liquid that fills the channel  31  contains solids sufficiently small in comparison with the intervals between antinodes and nodes, the solids receive forces toward the antinodes or nodes according to the physical property values of the solids and the solids are then captured at the positions of antinodes or nodes in the channel  31 . Accordingly, while the suspension supplied from the supply port  32  passes through the channel  31 , solids in the liquid are removed. The liquid is discharged from the outlet port  33  in a state of being cleared. 
         [0067]    As the captured solids flocculate into large aggregates, the aggregates settle toward the bottom, or the reflection plate  36 , of the channel  31  by their own weights. The concentrate port  34  is thus provided near the reflection plate  36 , thereby allowing most of solids having settled by their own weights to be selectively collected. 
         [0068]    As described above, the suspension  1  a supplied to the channel  31  passes through this channel  31 , to which the ultrasonic waves are emitted, thereby enabling the liquid to be separated into clear liquid  5   a  with a small number of solids in the liquid and concentrate liquid  4   a  with a large number of solids in the liquid and then collected. The clear liquid  5   a  passes through the outlet port  33  and the liquid feeding tube  63  and is discharged into the tank  50 . The concentrate liquid  4   a  passes through the concentrate port  34  and the liquid feeding tube  64  and is discharged into the tank  40 . 
       Advantageous Effects 
       [0069]    Advantageous effects (processing performance) in the case of using the suspension processing device are described below. The processing performance of the suspension processing device is evaluated with reference to the turbidity of sample liquid discharged from the outlet port  33 . The adopted sample liquid and output conditions of ultrasonic waves are as follows. 
         [0000]    (1) Sample liquid: suspension that contains pure water and alumina particles having an average particle diameter of 53 micrometers dispersed therein (average turbidity: 20.3 degrees).
 
(2) Ultrasonic waves: a sinusoidal wave having a frequency of 2.26 MHz is generated by a function generator, amplified by a power amplifier and input into the oscillator  35 .
 
         [0070]      FIG. 10  shows applied-voltage dependence of the turbidity of the liquid  5   a  discharged from the outlet port  33 . The horizontal axis indicates the applied voltage. The left vertical axis indicates the turbidity (degree) of the sample liquid discharged from the outlet port  33 . The right vertical axis indicates the reduction rate (%) of the turbidity, that is, ((turbidity before process)−(turbidity after process))*100/(turbidity before process). As the applied voltage increases, the turbidity of the discharged liquid decreases. In the case of an applied voltage of 200 V, the turbidity of the discharged liquid decreases to about two degrees (turbidity reduction rate: about 90%). 
       Embodiment 4  
       [0071]    In this embodiment, an example of the suspension processing device of Embodiment 4 using ultrasonic waves is described. 
       (Configuration of Suspension Processing Device) 
       [0072]      FIG. 11  is a configuration diagram of a suspension processing device using ultrasonic waves. 
         [0073]    The suspension processing device  30  includes a channel  31 , a supply port  32  that communicates with a liquid feeding tube  62 , an outlet port  33  that communicates with a liquid feeding tube  63 , a concentrate port  34  that communicates with a liquid feeding tube  64 , an oscillator  35  that generates ultrasonic waves, and a reflection plate  36  that reflects ultrasonic waves, and is arranged such that an end of the channel provided with the reflection plate  36  is oriented upward. 
         [0074]    The oscillator  35  and the reflection plate  36  are arranged at opposite ends of the channel  31  of the suspension processing device  30  so as to sandwich this channel  31  in the longitudinal axis direction. The oscillator  35  is arranged such that an oscillating surface is oriented upward to emit ultrasonic waves to the suspension in the channel  31 . The suspension processing device  30  of this embodiment also adopts a processing configuration similar to that in Embodiment  3  shown in  FIG. 7 . 
         [0075]    As with Embodiment 3 shown in  FIG. 8A , the oscillator  35  has an opening on the surface. The outlet port  33  is arranged directly below the opening, and communicates with the liquid feeding tube  63 . Liquid having passed through the liquid feeding tube  63  is discharged into a tank  50  shown in  FIG. 7 . The concentrate port  34  is disposed sideways at an end of the channel  31  nearer to the reflection plate  36 . The concentrate port  34  communicates with the liquid feeding tube  64 . The liquid having passed through the liquid feeding tube  64  is discharged into a tank  40  shown in  FIG. 7 . 
         [0076]    The supply port  32  is disposed sideways on the surface of the channel  31  between the oscillator  35  and the reflection plate  36 , and communicates with the liquid feeding tube  62 . The suspension  1   a,  supplied from the supply port  32  to the channel  31 , passes through this channel  31  and is then discharged to the outside of the suspension processing device  30  from the outlet port  33  or the concentrate port  34 . 
       (Operation/Process/Advantageous Effect) 
       [0077]    The oscillator  35  and the reflection plate  36  are arranged parallel to each other so as to sandwich the channel  31 , and ultrasonic waves are emitted into the channel  31 , thereby forming a standing wave in the channel  31 . Accordingly, regions with high sound pressure (nodes) and regions with low sound pressure (antinodes) cyclically appear along the channel  31 . 
         [0078]    At this time, if the channel  31  is filled with emulsion that contains droplets and a parent phase and the droplets are sufficiently smaller than the intervals of the antinodes and nodes, the droplets receive forces toward the antinodes or nodes according to the physical property values of the droplets and are then captured at the positions of antinodes or nodes in the channel  31 . Here, if the captured droplets have lower densities than the parent phase has, the captured droplets flocculate and float upward. The concentrate port  34  is thus provided near the reflection plate  36 , thereby allowing most of floating droplets to be selectively collected. 
       Embodiment 5  
       [0079]    In this embodiment, an example of a suspension processing device of Embodiment 5 using ultrasonic waves is described. 
       (Configuration of Suspension Processing Device) 
       [0080]      FIG. 12A  is a configuration diagram of the suspension processing device using ultrasonic waves. 
         [0081]    The suspension processing device  30  includes a channel  31  having a taper, a supply port  32  that communicates with a liquid feeding tube  62 , an outlet port  33  that communicates with a liquid feeding tube  63 , a concentrate port  34  that communicates with a liquid feeding tube  64 , an oscillator  35  that generates ultrasonic waves, and a reflection plate  36  that reflects ultrasonic waves, and is arranged such that an end of the channel provided with the oscillator  35  is oriented upward. 
         [0082]    The oscillator  35  and the reflection plate  36  are arranged at opposite ends of the channel  31  of the suspension processing device  30  so as to sandwich this channel  31  in the longitudinal axis direction. The oscillating surface of the oscillator  35  is arranged so as to emit ultrasonic waves to the suspension in the channel  31 . The suspension processing device  30  of this embodiment also adopts a processing configuration similar to that in Embodiment  3  shown in  FIG. 7 . 
         [0083]    As with Embodiment 3 shown in  FIG. 8A , the oscillator  35  has an opening on the surface. The outlet port  33  is arranged directly above the opening, and communicates with the liquid feeding tube  63 . Liquid having passed through the liquid feeding tube  63  is discharged into a tank  50  shown in  FIG. 7 . The concentrate port  34  is disposed sideways at an end of the channel  31  nearer to the reflection plate  36 . The concentrate port  34  communicates with the liquid feeding tube  64 . The liquid having passed through the liquid feeding tube  64  is discharged into a tank  40  shown in  FIG. 7 . 
         [0084]    The supply port  32  is disposed sideways on the surface of the channel  31  between the oscillator  35  and the reflection plate  36 , and communicates with the liquid feeding tube  62 .  FIG. 12B  shows a cross-sectional view taken along AB plane. The supply port  32  is disposed at a position deviating from the central axis CC′ or DD′ of the channel  31 . 
         [0085]    The suspension  1   a,  supplied from the supply port  32  to the channel  31 , passes through this channel  31  and is then discharged to the outside of the suspension processing device  30  from the outlet port  33  or the concentrate port  34 . 
       (Operation/Process/Advantageous Effect) 
       [0086]    The oscillator  35  and the reflection plate  36  are arranged parallel to each other so as to sandwich the channel  31 , and ultrasonic waves are emitted into the channel  31 , thereby forming a standing wave in the channel  31 . Accordingly, regions with high sound pressure (nodes) and regions with low sound pressure (antinodes) cyclically appear along the channel  31 . At this time, if liquid that fills the channel  31  contains solids sufficiently small in comparison with the intervals between antinodes and nodes, the solids receive forces toward the antinodes or nodes according to the physical property values of the solids and the solids are then captured at the positions of antinodes or nodes in the channel  31 . 
         [0087]    The outlet port  33  resides on the surface of the oscillator  35 . Accordingly, in a region in the channel  31  directly below the outlet port  33 , sound waves do not propagate. In this region, solids in the liquid cannot be captured. If a flow swirling around and away from a region directly below the outlet port  33  as shown in  FIG. 12C  can be generated, solids in the liquid can be effectively captured. 
         [0088]    A taper is formed at the channel  31  as shown in  FIG. 12A  to deviate the supply port  32  from the central axis of the channel  31  as shown in  FIG. 12B , thereby allowing the swirling flow as described above to be generated in the channel. Use of the swirling flow during the suspension clearing process can effectively capture the solids in the liquid, and improve the clearing performance of the suspension processing device. 
       Embodiment 6  
       [0089]    In this embodiment, an example of a suspension processing device of Embodiment 6 using ultrasonic waves is described. 
       (Configuration of Suspension Processing Device) 
       [0090]      FIGS. 13A and 13B  are configuration diagrams of the suspension processing device using ultrasonic waves. 
         [0091]    The suspension processing device  30  includes a channel  31 , a supply port  32  that communicates with a liquid feeding tube  62 , outlet ports  33  that communicate with respective liquid feeding tubes  63 , a concentrate port  34  that communicates with a liquid feeding tube  64 , oscillators  35  that generate ultrasonic waves, and a reflection plate  36  that reflects ultrasonic waves, and is arranged such that an end of the channel provided with the oscillators  35  is oriented upward. 
         [0092]    The multiple oscillators  35  and the reflection plate  36  are arranged at opposite ends of the channel  31  so as to sandwich this channel  31  in the longitudinal axis direction. All the multiple oscillators  35  are disposed on the same plane. These oscillators  35  are arranged with their oscillation surfaces facing downward so as to emit ultrasonic waves to the suspension in the channel  31 . As shown in  FIG. 13A , the multiple outlet ports  33  are arranged on the same surface on which the oscillators  35  reside. 
         [0093]    In the channel  31 , the outlet ports  33  are arranged in parallel to the oscillators  35  at an end where these oscillators are disposed, and communicate with the respective liquid feeding tubes  63 . Liquid having passed through the liquid feeding tubes  63  is discharged into a tank  50  shown in  FIG. 7 . The concentrate port  34  is disposed sideways at an end of the channel  31  nearer to the reflection plate  36 . The concentrate port  34  communicates with the liquid feeding tube  64 . The liquid having passed through the liquid feeding tube  64  is discharged into a tank  40  shown in  FIG. 7 . 
         [0094]    The supply port  32  is disposed sideways on the surface of the channel  31  between the oscillators  35  and the reflection plate  36 , and communicates with the liquid feeding tube  62 . The suspension  1   a,  supplied from the supply port  32  to the channel  31 , passes through this channel  31  and is then discharged to the outside of the suspension processing device  30  from the outlet port  33  or the concentrate port  34 . 
         [0095]    In general, if an oscillator is large, the oscillator surface does not uniformly oscillate, which reduces the sound pressure in a space. Accordingly, in the case of requiring a large oscillator surface, this embodiment with multiple small oscillators can improve the clearing performance of the suspension processing device more than the case of using a single oscillator. 
         [0096]    The present invention is not limited to the foregoing embodiments, and encompasses many types of variations. For instance, the foregoing embodiments have been described in detail for illustrating the present invention, and the present invention is not necessarily limited to the case of including the entire configuration described above. Alternatively, a part of the configuration of a certain embodiment may be replaced with a configuration element of another embodiment. Moreover, the configuration of a certain embodiment may be additionally provided with a configuration element of another embodiment. Furthermore, a part of the configuration of each embodiment may be additionally provided with another configuration element, deleted, or replaced with another configuration element. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           10  Suspension tank 
           20  Liquid feeding pump 
           30  Suspension processing device 
           31  Channel 
           32  Suspension supply port 
           33  Outlet port 
           34  Concentrate port 
           35  Ultrasonic oscillator 
           36  Ultrasonic reflection plate 
           40  Concentrate liquid tank 
           50  Clear liquid tank 
           61 - 64  Liquid feeding tubes 
           1   a  Suspension 
           4   a  Concentrate liquid 
           5   a  Clear liquid

Technology Classification (CPC): 1