Abstract:
An ejector system for a color sorter, eliminates particulate matter by air by detection of the particulate matter falling from an end of a transfer device at a predetermined position, and has a nozzle part in which a plurality of air flow paths that communicate with a plurality of nozzle holes are formed. A manifold part is provided with a plurality of electromagnetic valves that communicate with an air space communicating with a compressed air source and in which a plurality of air flow paths for supplying compressed air to the corresponding air flow paths in the nozzle part by the operation of the respective electromagnetic valves are formed. The nozzle part and the manifold part are separably integrated while open surfaces of the air flow paths in the nozzle part and open surfaces of the air flow paths in the manifold part are brought into contact with each other.

Description:
TECHNICAL FIELD 
     The present invention relates to an ejector system employed in a color sorter for sorting acceptable items and unacceptable items from among rice, wheat, or other grains; resin pellets; coffee beans; or other such particulate matter; or for eliminating foreign matter admixed into particulate matter. 
     BACKGROUND ART 
     Color sorters that sort acceptable items and unacceptable items in particulate matter, or that eliminate foreign matter admixed into particulate matter, are widely known in the prior art. 
     In a color sorter, particulate matter that is launched into the air, for example, from the edge of a chute or belt, is irradiated with light, whereupon the reflected light or transmitted light from the particulate matter is detected by sensors. The detection signal is compared with a reference value to identify unacceptable items or foreign matter, whereupon the unacceptable items or foreign matter are eliminated by being carried away with jets of air from ejector nozzles or the like, thereby sorting the particulate matter (see Patent Documents 1 and 2, for example). 
       FIG. 13  shows the ejector nozzle of the sorter disclosed in Patent Document 1. The ejector nozzle  101  has a plurality of slit-like air jet holes  102  and a plurality of holes  103  communicating with the air jet holes  102 , with hoses  104  that connect to a jet air supply, not shown, fitted into each of the plurality of holes  103  to jet air from the air jet holes  102 . 
     However, a problem with the ejector nozzle  101  in question is that difficulties arise when the hoses  104  dislodge from the holes  103 . Moreover, dust and dirt tends to collect in the ejector nozzle  101 , including the hoses  104 , making frequent cleaning and maintenance necessary. 
       FIG. 14  shows an air jetting device of the sorter disclosed in Patent Document 2. In the air jetting device  111  in question, a plurality of nozzle blocks  112 , a plurality of electromagnetic valves  113  connected in duct-wise fashion to the plurality of nozzle blocks  112 , and a single receiver tank  114  connected in duct-wise fashion plurality of electromagnetic valves  113  are arranged on a base  115 . In the air jetting device  111  in question, compressed air held in the receiver tank  114  is supplied through ducts to the electromagnetic valves  113 , and when a specific electromagnetic valve  113  is opened, air is supplied through a duct to the corresponding nozzle block  112 , whereupon air is jetted from a nozzle  116  formed at the tip of the nozzle block  112 . 
     In the air jetting device  111 , the nozzle blocks  112  and the electromagnetic valves  113  are respectively connected by ducts, so there is no problem of difficulties arising when the hoses  104  dislodge from the holes  103 , as in the aforedescribed ejector nozzle  101 . 
     However, in the air jetting device  111 , the plurality of nozzle blocks  112 , the plurality of electromagnetic valves  113 , and the receiver tank  114  are respectively connected by ducts and arranged on the base  115 , making cleaning and maintenance elaborate. 
     CITATION LIST 
     Patent Literature 
     Patent Document 1: Japanese Laid-Open Patent Application 8-252535 
     Patent Document 2: Japanese Laid-Open Patent Application 5-169037 
     SUMMARY OF INVENTION 
     Technical Problem 
     An object of the present invention is to offer an ejector system for a color sorter, having excellent cleaning and maintenance performance. 
     Solution to Problem 
     In order to attain the aforedescribed object, the present invention is an ejector system for a color sorter in which particulate matter falling from the end of a transfer means is detected at a predetermined position, and based on the result of the detection, the particulate matter is eliminated by air, characterized by being constituted from: a nozzle part in which a plurality of nozzle holes open at the front end, and in which are formed a plurality of air flow paths that communicate with the nozzle holes; and a manifold part in which is formed an air space communicating with a compressed air source, the manifold part being provided with a plurality of electromagnetic valves communicating with the air space, and in which are formed a plurality of air flow paths for supplying compressed air to corresponding air flow paths of the nozzle part by operation of the electromagnetic valves, the nozzle part and the manifold part being separably integrated in a state in which the open surfaces of the air flow paths in the nozzle part and the open surfaces of the air flow paths in the manifold part are brought in contact with each other. 
     In the present invention, in preferred practice, the open surfaces of the air flow paths in the nozzle part and the open surfaces of the air flow paths in the manifold part are fitted together as projections and recesses, and the nozzle part and the manifold part are separably integrated by a pair of rods extending from the manifold part being inserted into a pair of through-holes formed in the nozzle part. 
     In the present invention, in preferred practice, the nozzle part is constituted by screwing together a nozzle upper member and a nozzle lower member, the manifold part is constituted by screwing together a manifold upper member and a manifold lower member, and the air flow paths are formed on opposed surfaces of the respective upper and lower members. 
     In the present invention, in preferred practice, the arrangement with respect to the color sorter is such that the nozzle part is positioned on the flow path of the particulate matter, and the manifold part is positioned in the interior of the sorter body. 
     In the present invention, in preferred practice, at one side end of the upper surface of the nozzle part, there is arranged an air sweeper provided with nozzles opening towards the other side end of the upper surface of the nozzle part; in the nozzle part, there are formed air flow paths that communicate with the nozzles of the air sweeper; and in the manifold part, there are arranged electromagnetic valves that communicate with the air space, and there are formed air flow paths that, by operation of the electromagnetic valves, supply compressed air to air flow paths communicating with the nozzles of the air sweeper formed in the nozzle part. 
     In the present invention, in preferred practice, the plurality of electromagnetic valves are arranged in a plurality of rows, in a phase-shifted state with respect to the manifold part. 
     Advantageous Effects of Invention 
     According to the ejector system for a color sorter in the present invention, the nozzle part and the manifold part are separably integrated in a state in which the open surfaces of the air flow paths in the nozzle part and the open surfaces of the air flow paths in the manifold part are brought in contact with each other, whereby the difficulties with hose dislodgment encountered in the prior art do not arise, and cleaning and maintenance performance are excellent. 
     In the ejector system of the present invention, when the open surfaces of the air flow paths in the nozzle part and the open surfaces of the air flow paths in the manifold part are fitted together as projections and recesses, and a pair of rods extending from the manifold part are inserted into a pair of through-holes formed in the nozzle part, the nozzle part and the manifold part can be separated easily, improving the cleaning and maintenance performance. 
     In the ejector system of the present invention, when the nozzle part is constituted by screwing together a nozzle upper member and a nozzle lower member, the manifold part is constituted by screwing together a manifold upper member and a manifold lower member, and the air flow paths are formed on opposed surfaces of the respective upper and lower members, the upper and lower members of the nozzle part and of the manifold part can be separated easily, and the air flow paths can be cleaned easily. 
     When the ejector system of the present invention is arranged with respect to the color sorter such that the manifold part is positioned in the interior of the sorter body, the electromagnetic valves do not become soiled by dust and the like stirred up within the flow path in association with falling of the particulate matter, and the burden of cleaning and maintenance is reduced. 
     In the ejector system of the present invention, when one side end of the upper surface of the nozzle part has arranged thereon an air sweeper provided with nozzles opening towards the other side end of the upper surface of the nozzle part, starting material or dust and the like accumulating on the upper surface of the nozzle part can be automatically cleaned away, reducing the burden of cleaning and maintenance by workers. 
     In the ejector system of the present invention, when the plurality of electromagnetic valves are arranged in a plurality of rows in a phase-shifted state with respect to the manifold part, the number of nozzle holes can be increased, as compared to a case in which the electromagnetic valves are arranged in a single row. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exterior perspective view of a color sorter; 
         FIG. 2  is a simplified side sectional view of the color sorter; 
         FIG. 3  is a perspective view of an ejector system; 
         FIG. 4  is a fragmentary enlarged front view of the ejector system; 
         FIG. 5  is an exploded view of the ejector system; 
         FIG. 6  is a perspective view of a manifold part; 
         FIG. 7  is a plan view of a lower member constituting the ejector system; 
         FIG. 8  is a bottom view of an upper member constituting the ejector system; 
         FIG. 9  is a sectional view taken along A-A in  FIG. 3 ; 
         FIG. 10  is a sectional view taken along B-B in  FIG. 3 ; 
         FIG. 11  is a sectional view taken along C-C in  FIG. 3 ; 
         FIG. 12  is a partially enlarged view of  FIG. 2 ; 
         FIG. 13  is an ejector nozzle of the prior art; and 
         FIG. 14  is an air jetting device of the prior art. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following description of the embodiments of the present invention makes reference to the drawings. 
     &lt;Overview of Color Sorter&gt; 
     An overview of the color sorter is now described. 
       FIG. 1  is an example of a color sorter, showing an exterior perspective view thereof.  FIG. 2  shows a simplified side sectional view of the color sorter shown in  FIG. 1 . 
     The color sorter  1  in question is provided with a loading hopper  2  for loading particulate matter; a bucket conveyor  3  for lifting the particulate matter up into the top part of the sorter  1 ; a storage tank  4  for storing the lifted particulate matter; a rotary valve  5  arranged in the outlet of the storage tank  4 ; a sloping chute  6  having predetermined width, arranged below the rotary valve  5 ; a pair of optical detection devices  7   a ,  7   b  arranged to the front and back with the sloping chute  6  therebetween; an ejector system  8  arranged below the optical detection devices  7   a ,  7   b ; and a particulate matter discharge trough  9  arranged below the ejector system  8 . 
     The optical detection devices  7   a ,  7   b  are provided with sensors  10   a ,  10   b , mirrors  11   a ,  11   b , illumination means  12   a ,  12   b , and background means  13   a ,  13   b.    
     As the sensors  10   a ,  10   b , there are employed CCD line sensors or the like, constituted by a plurality of photodetector elements concatenated in a line pattern and assigned to a position in the width direction of the sloping chute  6 , for example. 
     The background means  13   a ,  13   b  are arranged to the back of a particulate matter detection position O on the optical axes of the sensors  10   a ,  10   b.    
     The optical detection devices  7   a ,  7   b  are adapted to detect particulate matter falling from the bottom edge of the sloping chute  6 , at positions in the width direction of the falling trajectory thereof. 
     The ejector system  8  is also provided with a nozzle part  20  having a plurality of nozzle holes assigned to positions in the width direction of the sloping chute  6 . Based on the results detected by the optical detection devices  7   a ,  7   b , particulate matter falling from the bottom edge of the sloping chute  6  is carried away by jets of air from nozzle holes at corresponding positions in the width direction of the falling trajectory thereof. 
     The particulate matter discharge trough  9  is provided with a satisfactory item discharge trough  9   a  arranged along the falling trajectory of the particulate matter from the bottom edge of the sloping chute  6 , and with an unsatisfactory item discharge trough  9   b  arranged at a position allowing the falling trajectory of the particulate matter to be modified by a jet of air from a nozzle hole of the nozzle part  20  constituting the ejector system  8 . 
     In the color sorter  1 , particulate matter loaded into the loading hopper  2  is lifted by the bucket conveyor  3  and stored in the storage tank  4 . The particulate matter, which is supplied from the storage tank  4  at a constant flow rate via the rotary valve  5 , spreads out across the width direction of the sloping chute  6 , and flows down naturally in a continuous manner. Falling particulate matter having been launched into the air from the bottom edge of the sloping chute  6  is illuminated by the illumination means  12   a ,  12   b  of the pair of optical detection devices  7   a ,  7   b , and with the background means  13   a ,  13   b  as the background, is imaged by the sensors  10   a ,  10   b  at a particulate matter detection position O extending linearly in the width direction of the sloping chute  6 , whereby unsatisfactory items or foreign matter are identified by comparing the voltage value of the image signal to a reference threshold value, or the like. Particulate matter identified as being satisfactory items then falls into the satisfactory item trough  9   a  arranged along a predetermined falling trajectory. Particulate matter identified as being unsatisfactory items or foreign matter is carried away by air jetted at predetermined timing from a nozzle hole that opens onto a predetermined position of the nozzle part  20  constituting the ejector system  8 , and falls into the unsatisfactory item trough  9   b.    
     Alternatively, satisfactory items, instead of unsatisfactory items or foreign matter, may be the particulate matter that is carried away by air in this way. 
     &lt;Ejector System&gt; 
     The ejector system of the present invention is now described. 
       FIG. 3  is a perspective view of an ejector system in an embodiment of the present invention. 
       FIG. 4  is a fragmentary enlarged front view of the ejector system shown in  FIG. 3 . 
     As shown in  FIG. 3 , the ejector system  8  in the present embodiment is constituted by a nozzle part  20  and a manifold part  30 . 
     The nozzle part  20  is constituted by screwing together a nozzle upper member  20   a  and a nozzle lower member  20   b . The manifold part  30  is constituted by screwing together a manifold upper member  30   a  and a manifold lower member  30   b.    
     Here, as will be clear from  FIG. 4 , a plurality of nozzle holes  21  open along the width direction at the front surface of the nozzle part  20 . Moreover, as shown in  FIGS. 3 and 4 , at one side end of the upper surface of the nozzle part  20 , there is arranged an air sweeper  23  provided with nozzles  22  that open towards the other side end of the upper surface thereof. 
     An attachment member  31  for attaching the ejector system  8  to the color sorter is screwed to the front of the upper face of the manifold upper member  30   a.    
       FIG. 5  shows a view of the ejector system shown in  FIG. 3 , with the nozzle part and the manifold part exploded.  FIG. 6  is a perspective view of the exploded manifold part. 
     As shown in  FIG. 5 , a laterally elongated recess part  32  is formed on the front surface of the manifold part  30 , and a pair of rods  33   a ,  33   b  are formed at either side of the recess part  32 . 
     Meanwhile, a laterally-elongated projection part  24  is formed on the back surface of the nozzle part  20 , and a pair of through-holes  25   a ,  25   b  are formed at either side of the projection part  24 . 
     Here, as will be clear from  FIG. 6 , a plurality of air flow paths  37  communicating with the nozzle holes  21  open along the width direction into the recess part  32  formed on the front surface of the manifold part  30 . Attachment holes  34   a ,  34   b  for the pair of rods  33   a ,  33   b  are formed at either side of the recess part  32 . 
     As shown in  FIGS. 4 and 6 , a plurality of electromagnetic valves  35   a ,  35   b  are arranged, in correspondence with the air flow paths  37  that open into the recess part  32 , along the width direction on the back face of the manifold upper member  30   a  and of the manifold lower member  30   b . A pair of air line connection parts  36   a ,  36   b  for connecting compressed air supply lines are arranged on the lower surface of the manifold lower member  30   b.    
     Here, as will be clear from  FIG. 4 , the electromagnetic valves  35   a ,  35   b  are arranged in a phase-shifted state in the width direction, with respect to the manifold upper and lower members  30   a ,  30   b.    
     As the electromagnetic valves  35   a ,  35   b  there may be employed any of the widely known types, and therefore a description is omitted here. 
     In the ejector system  8  of the present embodiment, the nozzle part  20  and the manifold part  30  are integrated by inserting the pair of rods  33   a ,  33   b  attached to the manifold part  30  into the pair of through-holes  25   a ,  25   b  formed in the nozzle part  20 ; and in a state in which the projection part  24  formed on the back surface of the nozzle part  20  has been mated into the recess part  32  formed on the front surface of the manifold part  30 , female thread parts of fastening members  26   a ,  26   b  shown in  FIG. 5  are threaded and tightened onto distal end male thread parts of the rods  33   a ,  33   b  that project out through the through-holes  25   a ,  25   b.    
     In the ejector system of the present embodiment, because the nozzle part  20  and the manifold part  30  are integrated through tightening of the fastening members  26   a ,  26   b , the nozzle part  20  and the manifold part  30  can be easily separated, for improved cleaning and maintenance performance. 
     Next,  FIG. 7  shows a plan view, in the detached state, of the nozzle upper member and the manifold upper member of the ejector system shown in  FIG. 3 .  FIG. 8  shows a bottom view of the nozzle upper member and the manifold upper member in the detached state in  FIG. 7 . 
     As shown in  FIG. 7 , a plurality of slots  37   b ,  27   b  continuing in the width direction from the front of the manifold lower member  30   b  to the front end of the nozzle lower member  20   b  are formed on the upper surfaces of the nozzle and manifold lower members  20   b ,  30   b.    
     At the back of the upper face of the manifold lower member  30   b , there is formed an air space recess part  40   b  that opens onto the lower surface through air supply holes  39   a ,  39   b . A plurality of communicating holes  38   b  are formed across the width direction of the manifold lower member  30   b.    
     The air space recess part  40   b  communicates with the plurality of electromagnetic valves  35   b  that have been arranged on the back surface of the manifold lower member  30   b . The communicating holes  38   b  communicate at the back end with the electromagnetic valves  35   b , and communicate alternately at the front end with the slots  37   b  formed at the front of the manifold lower member  30   b.    
     As shown in  FIG. 8 , a plurality of slots  37   a ,  27   a  continuing in the width direction from the front of the manifold upper member  30   a  to the front end of the nozzle upper member  20   a  are formed on the lower surfaces of the nozzle and manifold upper members  20   a ,  30   a.    
     At the back of the lower face of the manifold upper member  30   a , there is formed an air space recess part  40   a . A plurality of communicating holes  38   a  are formed across the width direction of the manifold upper member  30   a.    
     The air space recess part  40   a  communicates with the plurality of electromagnetic valves  35   a  that have been arranged on the back surface of the manifold upper member  30   a . The communicating holes  38   a  communicate at the back end with the electromagnetic valves  35   a , and communicate alternately at the front end with the slots  37   a  formed at the front of the manifold upper member  30   a.    
     In the ejector system of the present embodiment, a plurality of independent air passages  27 ,  37  affording communication between the nozzle holes  21  and the communicating holes  38   a ,  38   b  are constituted by the slots  27   b ,  37   b  formed on the upper surfaces of the nozzle and manifold lower members  20   b ,  30   b  shown in  FIG. 7 , and the slots  27   a ,  37   a  formed on the lower surfaces of the nozzle and manifold upper members  20   a ,  30   a  shown in  FIG. 8 . 
     At this time, the slots  37   b  that communicate with the communicating holes  38   b  formed in the manifold lower member  30   b  constitute air passages to the slots  37   a  that do not communicate with the communicating holes  38   a  formed in the manifold upper member  30   a . The slots  37   b  that do not communicate with the communicating holes  38   b  formed in the manifold lower member  30   b  constitute air passages to the slots  37   a  that communicate with the communicating holes  38   a  formed in the manifold upper member  30   a.    
     A communicating hole  29  communicating with the upper surface of the nozzle upper member  20   a  is formed in the slot  28   a  that has been formed at the left end of the lower surface of the nozzle upper member  20   a  shown in  FIG. 8 . The slot  28   a  in question constitutes an air passage  28  communicating with the slot  28   b  that has been formed at the left end of the upper surface of the nozzle lower member  20   b  shown in  FIG. 7 , as well as with the nozzles  22  of the air sweeper  23  arranged on the upper surface of the nozzle part  20   
     In the ejector system of the present embodiment, an air space  40 , discussed below, is constituted by the air space recess part  40   b  formed in the upper surface of the manifold lower member  30   b  shown in  FIG. 7 , and the air space recess part  40   a  formed in the lower surface of the manifold upper member  30   a  shown in  FIG. 8 . The air space  40  is a space for storing compressed air supplied from a compressed air source, not shown, to the air supply holes  39   a ,  39   b  that open onto the lower surface of the manifold lower member  30   b.    
       FIG. 9  shows an air flow path inside the nozzle part and the manifold part, taken along section A-A in  FIG. 3 .  FIG. 10  shows an air flow path inside the nozzle part and the manifold part, taken along section B-B in  FIG. 3 . 
     The air flow path shown in  FIG. 9 , via the electromagnetic valve  35   b  arranged in the manifold lower member  30   b , affords communication between the air space  40  formed in the manifold part  30  and the communicating hole  38   b  formed in the lower member  30   b ; and via the air flow path  37  formed at the front of the manifold part  30  and the air flow path  27  formed in the nozzle part  20 , affords communication with the nozzle hole  21  that opens onto the front surface of the nozzle part  20 . 
     The air flow path shown in  FIG. 10 , via the electromagnetic valve  35   a  arranged in the manifold upper member  30   a , affords communication between the air space  40  formed in the manifold part  30  and the communicating hole  38   a  formed in the upper member  30   a ; and via the air flow path  37  formed at the front of the manifold part  30  and the air flow path  27  formed in the nozzle part  20 , affords communication with the nozzle hole  21  that opens onto the front surface of the nozzle part  20 . 
     The air flow paths shown in  FIGS. 9 and 10  supply air from the air space  40  to the nozzle holes  21  through opening of the electromagnetic valves  35   a ,  35   b.    
     For example, in the color sorter  1  shown in  FIGS. 1 and 2 , in a case in which an unsatisfactory item is detected by the optical detection devices  7   a ,  7   b , and a position in the width direction of the falling trajectory of the particulate matter detected to be an unsatisfactory item corresponds to the position of the nozzle holes  21  shown in  FIG. 9  or  10 , the ejector system  8  of the present embodiment will open the electromagnetic valve  35   a ,  35   b  shown in  FIG. 9  or  10 , and thereby jet high pressure air stored in the air space  40 , from either of the aforedescribed nozzle holes  21  over the predetermined air flow path. 
       FIG. 11  shows an air flow path inside the nozzle part and the manifold part, taken along C-C in  FIG. 3 . 
     The air flow path shown in  FIG. 11 , via the electromagnetic valve  35   a  arranged in the manifold upper member  30   a , affords communication between the air space  40  formed in the manifold part  30  and the communicating hole  38   a  formed in the upper member  30   a ; and via the communicating hole  29 , affords communication between the air flow path  37  formed at the front of the manifold part  30  and the air flow path  28  formed in the nozzle part  20 , and the nozzle  22  of the air sweeper  23  arranged on the upper surface of the nozzle part  20 . 
     The air flow path shown in  FIG. 11  likewise supplies the nozzle  22  of the air sweeper  23  with air from the air space  40 , through opening of the electromagnetic valve  35   a.    
     For example, by utilizing a timer in the color sorter  1  shown in  FIGS. 1 and 2  to periodically open the electromagnetic valve  35   a  and jet air from the nozzle  22  depending on the running time of the color sorter  1 , or by utilizing a sensor to open the electromagnetic valve  35   a  and jet air from the nozzle  22  depending on the condition of accumulation of dust or the like on the upper surface of the nozzle part  20 , the upper surface of the nozzle part  20  can be cleaned automatically. Moreover, by switching the opening/closing action of the electromagnetic valve  35   a  to manual, the upper surface of the nozzle part  20  can be cleaned automatically through manual operation by a worker. 
     In the above manner, in the ejector system  8  of the present embodiment, the nozzle part  20  and the manifold part  30  are constituted such that it is possible for them to be easily assembled and separated, improving the cleaning and maintenance performance. 
     Moreover, in the ejector system  8  of the present embodiment, the nozzle part  20  and the manifold part  30  are constituted by screwing together upper and lower members, and therefore the upper and lower members can be easily separated, so that the air passages  27 ,  37  formed on the opposed surfaces of the upper and lower members can be easily cleaned. 
     In the ejector system  8  of the present embodiment, at one side end of the upper surface of the nozzle part  20 , there has been arranged the air sweeper  23  provided with nozzles  22  that open towards the other side end of the upper surface of the nozzle part  20 , whereby starting material, dust, and the like accumulating on the upper surface of the nozzle part  20  can be cleaned automatically, and the burden of cleaning or maintenance performed by workers can be reduced. 
     The ejector system  8  of the present embodiment is constituted such that when the plurality of electromagnetic valves  35   a ,  35   b  are respectively arranged on the upper and lower members  30   a ,  30   b  constituting the manifold part  30 , the phase of the electromagnetic valves  35   a  arranged on the upper member  30   a  and that of the electromagnetic valves  35   b  arranged on the lower member  30   b  are made different from one another, and therefore the number of nozzle holes that open onto the front surface of the nozzle part can be increased to double, as compared with a case in which the electromagnetic valves are arranged on one member only. 
     In the ejector system of the aforedescribed embodiment, the nozzle part  20  and the manifold part  30  are integrated by inserting the pair of rods  33   a ,  33   b  attached to the manifold part  30  into the pair of through-holes  25   a ,  25   b  formed in the nozzle part  20 , and threading and tightening the female thread parts of the fastening members  26   a ,  26   b  onto the distal end male thread parts of the rods  33   a ,  33   b  that project out through the through-holes  25   a ,  25   b ; however, the nozzle part  20  and the manifold part  30  may be integrated by other means. 
     In the ejector system of the aforedescribed embodiment, the air flow paths  27 ,  37  that are formed on the opposed surfaces of the upper and lower members of the nozzle part  20  and the manifold part  30  are constituted by slots formed in the upper surface of the lower members and slots formed in the lower surface of the upper members; however, provided that the air flow paths  27 ,  37  are formed in the opposed surfaces of the upper and lower members of the nozzle part  20  and the manifold part  30 , it is acceptable for the slots constituting the air flow paths  27 ,  37  to be formed in either the upper or lower member only. 
     In the ejector system of the aforedescribed embodiment, the nozzle part  20  and the manifold part  30  are respectively constituted by screwing together an upper and a lower member; however, these could be respectively constituted as single members. In this case, the air flow paths formed in the parts may be formed as through-holes. 
     In the ejector system of the aforedescribed embodiment, the air sweeper  23  is arranged on the upper surface of the nozzle part  20 ; however, the arrangement of the air sweeper  23  is arbitrary. 
     In the ejector system of the aforedescribed embodiment, the electromagnetic valves  35  are arranged in two rows on the manifold part  30 ; however, the electromagnetic valves  35  may instead be arranged in three or more rows, or arranged in a single row only, as in the prior art. 
     Example of Implementation of Ejector System in a Color Sorter 
       FIG. 12  is an example of implementation of the ejector system of the present invention in a color sorter, and shows a partial enlarged view of  FIG. 2 . 
     As shown in  FIG. 12 , the ejector system  8  of the present embodiment is fastened to the body of the color sorter by the attachment member  31 , which has been screwed to the upper surface at the front of the manifold upper member  30   a.    
     In the process, the ejector system  8  is arranged such that the nozzle part  20  is positioned on the flow path of the particulate matter, and the manifold part  30  is positioned in the interior of the sorter body. 
     In the ejector system  8  of the present embodiment, because the manifold part  30  is positioned in the interior of the sorter body, soiling of the electromagnetic valves by dust and the like stirred up within the flow path in association with falling of the particulate matter can be prevented. 
     The ejector system  8  of the present embodiment is not limited to application in the aforedescribed color sorter  1 ; implementation in all manner of color sorters is possible. 
     The present invention is not limited to the aforedescribed embodiments; various modifications of the constitution thereof can be made, as appropriate, without departing from the scope of the claims. 
     INDUSTRIAL APPLICABILITY 
     The ejector system employed in the color sorter of the present invention has excellent cleaning and maintenance performance by virtue of a constitution whereby the nozzle part and the manifold part are integrated by a separable structure, and the application value is accordingly high. 
     REFERENCE SIGNS LIST 
       1  Color sorter 
       2  Loading hopper 
       3  Bucket conveyor 
       4  Storage tank 
       5  Rotary valve 
       6  Sloping chute 
       7   a ,  7   b  Optical detection devices 
       8  Ejector system 
       9  Particulate matter discharge trough 
       9   a  Satisfactory item discharge trough 
       9   b  Unsatisfactory item discharge trough 
       10   a ,  10   b  Sensors 
       11   a ,  11   b  Mirrors 
       12   a ,  12   b  Illumination means 
       13   a ,  13   b  Background means 
       20  Nozzle part 
       20   a  Nozzle upper member 
       20   b  Nozzle lower member 
       21  Nozzle holes 
       22  Nozzles 
       23  Air sweeper 
       24  Projection part 
       25   a ,  25   b  Through holes 
       26   a ,  26   b  Fastening members 
       27  Air flow paths 
       27   a ,  27   b  Slots 
       28  Air flow paths 
       28   a ,  28   b  Slots 
       30  Manifold part 
       30   a  Manifold upper member 
       30   b  Manifold lower member 
       31  Attachment member 
       32  Recess part 
       33   a ,  33   b  Rods 
       34   a ,  34   b  Rod attachment holes 
       35   a ,  35   b  Electromagnetic valves 
       36   a ,  36   b  Air line connection parts 
       37  Air flow paths 
       37   a ,  37   b  Slots 
       38   a ,  38   b  Communicating holes 
       39   a ,  39   b  Air supply holes 
       40  Air space 
       40   a ,  40   b  Air space recess parts