Abstract:
An insect blowing and suction system including at least two tangential blowers, each creating an air stream at a suitable angle relative to the ground but in opposite directions to each other. The two air streams combine and are diverted upward, thereby lifting insects upward. The upward air velocity is increased by at least one upper axial blower that sucks the air from the housing.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a system for the removal of harmful insects, and more particularly, to a system for the detachment of insects from vegetation, by means of suction and removal of the insects. 
         [0002]    Many types of agricultural vegetation, mostly in greenhouses and particularly herbs, such as chives and parsley in greenhouses, are subject to severe damage by insects. Despite use of protective screens and chemical pesticides, the damage isn&#39;t sufficiently controlled. Likewise, there is a demand in kosher consumer markets, according to Jewish Halakha (Jewish Law), to provide clean produce that is completely free of insects, dead or alive. Insects can be detached and removed from the plants by means of suction with an air stream; however sufficiently effective achievement relies upon air stream performance strong enough to detach the insects from the plants in spite of their powerful grasp. 
         [0003]    There is therefore a need for an insect suction system which will generate a powerful directed air stream on an area of influence that will detach and remove the harmful insects from all parts of the vegetation. 
       SUMMARY OF INVENTION 
       [0004]    According to the present invention there is provided an insect blowing and suction system including: a suction assembly for creating an upward air stream, the suction assembly including a housing that includes a lower first end, and a lower second end; a first tangential blower located at the lower first end; and a second tangential blower located at the lower second end, wherein each of the first and second tangential blowers create respective air streams on the ground towards each other, the air streams combining to create an upward air stream into the housing, whereby insects on the ground are suctioned into the housing. 
         [0005]    A basic insect blowing and suction system of the present invention is based on a suction assembly for creating an upward air stream. The suction assembly includes a housing with first and second lower ends and with first and second tangential blowers located at those lower ends. The tangential blowers create respective air streams along the ground towards each other. The air streams combine where they meet to create an upward air stream into the housing, thereby sucking up insects from the ground into the housing. 
         [0006]    The first and second tangential blowers are oriented to blow air at a predetermined angle downward from a line drawn between the first tangential blower and the second tangential blower, and one or both of the first and second tangential blowers may include a heating mechanism for heating the air stream. The housing may also include an air inlet at the lower side between the lower first end and the lower second end for receiving the insects in the housing, and may include an air outlet at the upper side for allowing the insects to exit the housing and enter the bag or other collecting mechanism. The suction assembly preferably also includes an axial blower for creating an upward suction inside the housing, and preferably includes a collecting mechanism located above the housing for collecting the insects, such as a bag, perforated container, bin or cyclone. 
         [0007]    Preferably, the system also includes a generator to power the suction assembly and a chassis to support the suction assembly and the generator, and one or more wheels connected to the chassis for moving the chassis along the ground. Preferably, the system also includes one or more height adjustment mechanisms connected to the chassis for raising or lowering either the whole chassis or just the suction assembly relative to the ground. 
         [0008]    The first tangential blower is used since its air velocity and its drag force are more powerful for detaching insects than those of the suction of the axial blower, and the second tangential blower is incorporated in order to stop the insects from getting out of the housing and to help direct the insects into the suction air stream. 
         [0009]    According to the present invention there is provided a method of removing insects from vegetation on the ground including creating a first air stream on the ground towards the vegetation, creating a second air stream on the ground towards the first air stream, the first and second air streams colliding and combining at at least a portion of the vegetation at a velocity powerful enough to remove insects from vegetation, and positioning a housing above the vegetation, to divert the combined first and second air streams upward into the housing, thereby suctioning insects from the vegetation into the housing. The method preferably also includes creating a suction inside the housing for urging the combined first and second air streams to flow upward into the housing. Preferably, the velocity of at least one of the first and second air stream is greater than the velocity of the suction. Preferably, the velocity of the diverted air streams is of a magnitude sufficient to detach an insect from vegetation. Either one or both of the first and second air streams may be heated to weaken the insects grip on the vegetation. The insects removed from the vegetation and suctioned into the housing may be collected in a collecting mechanism, such as a bag, perforated container, bin or cyclone which is positioned at the upper side of the housing where the insects exit the housing. 
         [0010]    Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]    The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: 
           [0012]      FIG. 1  is an isometric view of an exemplary, illustrative embodiment of an insect suction system according to the present invention. 
           [0013]      FIG. 2  is an isometric view of a suction assembly according to the present invention. 
           [0014]      FIG. 3  is an exploded isometric view of a suction assembly according to the present invention. 
           [0015]      FIG. 4  is a top view of the suction assembly according to the present invention, upon which the section plane a-a is marked. 
           [0016]      FIG. 5  is a cross-sectional side view through a-a of the suction assembly according to the present invention. 
       
    
    
       [0017]    The elements shown herein in the illustrations are presented in a manner that enables a clear understanding of their function, and the scales, size relations, and shapes do not in any way limit the scope of the invention. 
       DESCRIPTION OF EMBODIMENTS 
       [0018]    The principles and operation of an insect suction system according to the present invention may be better understood with reference to the drawings and the accompanying description. 
         [0019]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The materials, dimensions, methods, and examples provided herein are illustrative only and are not intended to be limiting. 
         [0020]    The following is a legend of the elements described in the illustrations and accompanying description:
     20  suction assembly     20   w  suction assembly width     20   l  suction assembly length     21  housing     21   a  housing wall     21   il  air inlet     21   lfe  lower first end     21   lse  lower second end     21   ol  air outlet     21   u  upper side     22  tangential blower     22   a  heating element     23  axial blower     24  tangential blower impeller     25  collecting bag     25   a  bag wall     31  generator     41  wheel     51  chassis     61  height adjustment mechanism     71  ground     71   a  ground surface     72  vegetation     81  air stream     91  insect     100  insect suction system   α angle, measured between the direction of the air coming out of the tangential blower and the ground surface   β angle, measured downward from an imaginary line connecting the two tangential blowers   A area (the section area of the insect perpendicular to the air stream)   D traveling direction   F force   C D  drag coefficient   V air stream velocity   ρ air density   
 
         [0055]    Referring now to the drawings,  FIG. 1  is an isometric view of an exemplary, illustrative embodiment of an insect suction system  100 , according to the present invention. 
         [0056]    Insect suction system  100  includes a carrying chassis  51 , a suction assembly  20 , a generator  31 , wheels  41 , and height adjustment mechanisms  61 . Generator  31  can serve as a power source for the activation of two tangential blowers  22  and an axial blower  23 , however this is in no way limiting their method of activation according to the present invention. 
         [0057]    Chassis  51  is connected to four height adjustment mechanisms  61 , each of which serves to calibrate the distance of one of the four wheels  41  from the suction assembly  20 , in order to determine the distance between the suction assembly  20  and the ground (not shown in  FIG. 1 ), which is required for conforming to the height of the vegetation, (not shown in  FIG. 1 ). Note that the number of wheels  41  is not limited to four, and according to the present invention there can be any number of wheels, even just one wheel in a wheelbarrow-like configuration. In an alternative embodiment (not shown) a height adjustment mechanism may be positioned between the chassis and the suction assembly to raise or lower the suction assembly relative to the chassis (and hence the ground) while the height of the chassis remains fixed. While the insect suction system  100  shown in  FIG. 1  is designed to be moved manually along the ground by pushing or pulling, other embodiments may be possible. For example it may include an engine for the purpose of self-propulsion, or it may be carried on a trailer or pulled by a tractor. 
         [0058]      FIG. 2  is an isometric view of an exemplary, illustrative embodiment of a suction assembly  20 . Suction assembly  20  includes a housing  21 , two tangential blowers  22 , and an axial blower  23 . Housing  21  includes a lower first end  21   lfe,  a lower second end  21   lse,  and an upper side  21   u.  Each of lower first end  21   lfe  and lower second end  21   lse  of housing  21  is either touching or adjacent a tangential blower  22 . Upper side  21   u  of housing  21  is either touching or adjacent to axial blower  23 . Tangential blowers  22  are oriented inward-facing relative to housing  21  and angled downward such that air is blown towards each other and down, similar to a ‘V’. Axial blower  23  is oriented upward-facing such that air is blown upward, creating a suction inside housing  21 . 
         [0059]      FIG. 3  is an exploded isometric view of suction assembly  20 , showing housing  21 , axial blower  23  and tangential blowers  22  in which are tangential blower impellers  24 . 
         [0060]      FIG. 4  is a top view of suction assembly  20  having a length  20   l  and a width  20   w,  and upon which the section plane a-a is marked. 
         [0061]      FIG. 5  is a cross-sectional side view of suction assembly  20  taken across a-a, which demonstrates its operation when used on vegetation. 
         [0062]    In operation, air streams  81  are created by air movement caused by tangential blowers  22  and axial blower  23 . The direction of air stream  81  emerging from each tangential blower  22  is at an angle α toward a ground surface  71   a,  and at an angle β downward relative to an imaginary line connecting the two tangential blowers  22 . 
         [0063]    When ground surface  71   a  is flat and suction assembly  20  is perpendicular to ground surface  71   a:    
         [0000]      β=α.
 
         [0064]    Each air stream  81  created by tangential blowers  22  hits the ground  71 , and becomes parallel to the ground surface  71   a,  whereupon they collide with each other and after pushing each other they combine into an upward stream, practically perpendicular to ground surface  71   a  the force of which is magnified by the suction created by axial blower  23 . The angle β may be set to be bigger or smaller than a when one side of the system is raised or lowered more than the other side. 
         [0065]    The traveling velocity of the suction assembly  20  in the traveling direction D is small relative to the air stream velocity V near ground surface  71   a,  and its effect on the air stream can be minimal. 
         [0066]    Heating elements  22   a  can be added in tangential blowers  22 , to heat the air, which will heat the insects  91 , thus weakening their grip on the vegetation  72 . 
         [0067]    For the streaming air to detach an insect  91  from the vegetation  72  and move it upwards, it must activate a force F on the insect  91  that is equal to or greater than the insect&#39;s weight, and furthermore, greater than the grasp of the insect  91  on the vegetation  72 . While it is well known to a person skilled in the art that a variety of factors influence whether or not any particular insect will be detached from the vegetation, the chances for detaching an insect are substantially increased when the air stream velocity V is at least: 
         [0000]    
       
         
           
             V 
             = 
             
               
                 
                   2 
                    
                   
                       
                   
                    
                   F 
                 
                 
                   ρ 
                    
                   
                       
                   
                    
                   
                     C 
                     D 
                   
                    
                   A 
                 
               
             
           
         
       
     
         [0068]    The air stream velocity V is increased under the influence of the action of the axial blower  23 . 
         [0069]    The drag coefficient C D  and the area A vary, of course, from one insect  91  to another, as does the force F. 
         [0070]    Insects  91  that have been detached from the vegetation  72  travel upward in air stream  81  and enter housing  21  through an air inlet  21   il,  which is at the bottom side of the housing  21 , and move between the housing walls  21   a  until they exit through the air outlet  21   ol  located at upper side  21   u  of the housing  21 . 
         [0071]    The spatial shape of housing walls  21   a  can be as shown in the present illustration, however they can also be in other shapes, and the shape affects the air stream regimen. Selection of the optimal shape for any given application is well within the ability of one ordinarily skilled in the art. 
         [0072]    Likewise, the present invention is not limited to any specific ratio between the suction assembly width  20   w  and the suction assembly length  20   l.  Thus, for example, these dimensions can be equal. 
         [0073]    Each insect  91  that emerges from air outlet  21   ol  is collected into a collecting bag  25  that has a bag wall  25   a  made of a sufficiently large net, with small enough holes to prevent the passage of the insects  91  however they do not significantly damage the air stream velocity V in the vicinity of the ground surface  71   a.  In other embodiments, an alternative collecting mechanism, such as a perforated container, bin or cyclone may be used in place of collecting bag  21  so long as the material from which the collecting mechanism is made is porous enough to allow air to escape while still capable of trapping insects inside. 
         [0074]    The air streams coming out of the tangential blowers have momentum that keep the stream relatively narrow, whereas the air streams coming into the axial blower have no such momentum. Consequently, the air streams coming out of the tangential blowers maintain the air velocity for a longer distance, and the drag forces and the detaching forces it inflicts on insects are higher. Thus, the first of the two tangential blowers  22  is used since its air velocity and its drag force are more powerful for detaching insects inside the canopy than the air velocity and drag force of the suction of axial blower  23 , and the second of the two tangential blowers  22  is incorporated both to stop the insects from getting out of housing  21  and to help direct the insects into the suction air stream. 
         [0075]    Experimentally, satisfactory results were achieved when the air stream had a velocity of approximately 8 m/s in the area where the air starts flowing upward. 
         [0076]    While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.