Patent Publication Number: US-9850649-B2

Title: Vortex flow type water surface control device for draining device

Description:
TECHNICAL FIELD 
     The present invention particularly relates to a device that restrains contaminants flowing out to rivers and the like inside a storm overflow chamber that separates wastewater and rainwater from each other, in a combined sewer system that applies drainage treatment to rainwater and wastewater in the same sewer. 
     BACKGROUND ART 
     As countermeasures against the flowing out of contaminants in the storm overflow chamber, a vertical control plate  6  as described in Patent Document 1 (JP 2004-238833 A) (refer to Abstract and  FIG. 1 ) is known. The vertical control plate  6  generates a vortex near an opening of an intercepting pipe  3 . Floating contaminants  5  are drawn into the vortex, and then contaminants  5  are drawn into the intercepting pipe  3 . 
     SUMMARY OF THE INVENTION 
     However, it is not always clear where the vertical control plate  6  should be arranged to facilitate the drawing of the contaminants  5  into the intercepting pipe  3 . 
     It is therefore an object of the present invention to provide the control plate at a preferred position in the storm overflow chamber. 
     According to the present invention, a vortex flow type water surface control device for a draining device includes: a storm overflow chamber that is connected to an inflow pipe, an intercepting pipe, and an outflow pipe; and a control plate that is arranged in front of an opening portion of the intercepting pipe opening to the storm overflow chamber, wherein a relation (1) 0.5 D≦X≦0.7 D and 0.83 D≦Y≦1.5 D holds true, or a relation (2) 0.4 D≦X≦0.5 D and 1.0 D≦Y≦1.5 D holds true, where D represents an inner diameter of the opening portion, X represents a projection length of the control plate with respect to the opening portion, and Y represents a distance between the control plate and the opening portion. 
     The thus constructed vortex flow type water surface control device for a draining device includes a storm overflow chamber that is connected to an inflow pipe, an intercepting pipe, and an outflow pipe. A control plate is arranged in front of an opening portion of the intercepting pipe opening to the storm overflow chamber. A relation (1) 0.5 D≦X≦0.7 D and 0.83 D≦Y≦1.5 D holds true, or a relation (2) 0.4 D≦X≦0.5 D and 1.0 D≦Y≦1.5 D holds true, where D represents an inner diameter of the opening portion, X represents a projection length of the control plate with respect to the opening portion, and Y represents a distance between the control plate and the opening portion. 
     According to the present invention, a vortex flow type water surface control device for a draining device includes: a storm overflow chamber that is connected to an inflow pipe, an intercepting pipe, and an outflow pipe; and a control plate that is arranged in front of an opening portion of the intercepting pipe opening to the storm overflow chamber, wherein a relation 0.4 D≦X≦0.7 D holds true, where D represents an inner diameter of the opening portion, and X represents a projection length of the control plate with respect to the opening portion. 
     According to the present invention, a vortex flow type water surface control device for a draining device includes: a storm overflow chamber that is connected to an inflow pipe, an intercepting pipe, and an outflow pipe; and a control plate that is arranged in front of an opening portion of the intercepting pipe opening to the storm overflow chamber, wherein a relation 0.83 D≦Y≦1.5 D holds true, where D represents an inner diameter of the opening portion, and Y represents a distance between the control plate and the opening portion. 
     According to the vortex flow type water surface control device for a draining device of the present invention, the storm overflow chamber may include a separating weir for separating the inflow pipe and the intercepting pipe from the outflow pipe. 
     According to the present invention, the vortex flow type water surface control device for a draining device may include a guide wall that separates the inflow pipe and the intercepting pipe from the outflow pipe, wherein a top end of the guide wall is higher than a top end of the separating weir. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a plan view of a storm overflow chamber  10  according to an embodiment of the present invention; and 
         FIG. 2  is a front perspective view of the storm overflow chamber  10  according to an embodiment of the present invention. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     A description will now be given of an embodiment of the present invention referring to drawings. 
       FIG. 1  is a plan view of a storm overflow chamber  10  according to an embodiment of the present invention.  FIG. 2  is a front perspective view of the storm overflow chamber  10  according to an embodiment of the present invention. It should be noted that a neighborhood of an outflow pipe  4  is omitted in  FIG. 2 . 
     An inflow pipe  2 , an intercepting pipe  3 , and the outflow pipe  4  are connected to the storm overflow chamber  10 . Inflow water such as household wastewater, wastewater, and rainwater flows in the inflow pipe  2 , and flows into the storm overflow chamber  10 . The inflow water which has flown into the storm overflow chamber  10  is guided by the intercepting pipe  3  to a sewage treatment plant. 
     Although the inflow pipe  2 , the intercepting pipe  3 , and the outflow pipe  4  are arranged as described below in  FIG. 1 , they are not necessarily so arranged. An extension direction of the inflow pipe  2  and an extension direction of the intercepting pipe  3  are the same. An extension direction of the outflow pipe  4  is orthogonal to the extension directions of the inflow pipe  2  and the intercepting pipe  3 . An opening of the inflow pipe  2  and an opening of the intercepting pipe  3  face each other in parallel. An opening of the outflow pipe  4  is arranged on the right side seen from the opening of the inflow pipe  2 . The openings of the inflow pipe  2  and the intercepting pipe  3  are arranged on the left side of the storm overflow chamber  10 . The opening of the outflow pipe  4  is arranged on the right side of the storm overflow chamber  10 . 
     A separating weir  1  separates the inflow pipe  2  and the intercepting pipe  3  from the outflow pipe  4 . The inflow water which has overflown the separating weir  1  due to an increase of the inflow water during rainfall or the like is discharged through the outflow pipe  4  to a river or the like. 
     An opening portion of the intercepting pipe  3  opening to the storm overflow chamber  10  is referred to as an opening portion  3   a . A control plate  6  is arranged in front of the opening portion  3   a . Although a bottom end of the control plate  6  is arranged as high as a top portion of the intercepting pipe  3 , for example, they are not necessarily limited to the same height. 
     A guide wall  7  separates the inflow pipe  2  and the intercepting pipe  3  from the outflow pipe  4 . A bottom end of the guide wall  7  is arranged slightly lower than a top end of the separating weir  1 . A top end of the guide wall  7  is higher than a top end of the separating weir  1 . 
     A vortex flow type water surface control device for a draining device according to an embodiment of the present invention includes the storm overflow chamber  10 , the control plate  6 , and the guide wall  7 . The storm overflow chamber  10  includes the separating weir  1 . 
     A description will now be given of a state of water flows in the storm overflow chamber  10  according to an embodiment of the present invention. 
     Arrows shown in  FIG. 1  represent flows of the inflow water flowing from the inflow pipe  2 . The inflow water flows toward the intercepting pipe  3 . Now, it is assumed that the water level of the inflow water is increased due to rainfall or the like, and exceeds the bottom end of the control plate  6  to a certain extent. Then, a part of the inflow water is blocked by the control plate  6 . Further, the control plate  6  and the separating weir  1  are separated from each other, and the inflow water which has flown in this portion tends to flow around the control plate  6 . As a result, a vortex is generated in the neighborhood of the control plate  6 . The vortex draws contaminants floating on the inflow water thereinto. The contaminants which have been drawn into the vortex are then drawn into the intercepting pipe  3 . 
     On this occasion, Y represents a distance (referred to as “arrangement position”) between the control plate  6  and the opening portion  3   a  (or an inner wall surface of the storm overflow chamber  10  to which the intercepting pipe  3  opens). X represents a length in which the control plate  6  is projected with respect to the opening  3   a  (referred to as “projection length”). It should be noted that the projection length X is considered to be a distance between a right end of the control plate  6  and a left end of the opening portion  3   a  referring to  FIG. 2 . Moreover, D represents an inner diameter of the opening portion  3   a.    
     Table 1 shows experiment results in which it is determined whether contaminants flow into the intercepting pipe  3  or not for various values of the projection length X and the arrangement position Y. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 Arrangement 
                 Projection length X 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 position Y 
                 0.3D 
                 0.4D 
                 0.5D 
                 0.6D 
                 0.7D 
               
               
                   
                   
               
               
                   
                 0.83D  
                 x 
                 x 
                 Δ 
                 Δ 
                 ∘ 
               
               
                   
                 1.0D 
                 x 
                 Δ 
                 ∘ 
                 ∘ 
                 ∘ 
               
               
                   
                 1.5D 
                 x 
                 Δ 
                 Δ 
                 Δ 
                 Δ 
               
               
                   
                 2.0D 
                 x 
                 x 
                 x 
                 x 
                 x 
               
               
                   
                   
               
               
                   
                 Note) 
               
               
                   
                 Symbols represent how contaminants are drawn into the intercepting pipe as follows. 
               
               
                   
                 x: Do not flow into the intercepting pipe. 
               
               
                   
                 Δ: Gradually flow into the intercepting pipe. 
               
               
                   
                 ∘: Continuously flow into the intercepting pipe. 
               
            
           
         
       
     
     From the experiment result, it is appreciated that, preferably: 
     a relation (1) 0.5 D≦X≦0.7 D and 0.83 D≦Y≦1.5 D holds true, or 
     a relation (2) 0.4 D≦X≦0.5 D and 1.0 D≦Y≦1.5 D holds true. 
     If the projection length X is less than 0.4 D or 0.5 D, an effect of blocking the flow toward the intercepting pipe  3  is not sufficiently provided, and a vortex strong enough to draw contaminants thereinto is generated with less possibility. If the projection length X exceeds 0.7 D, a material cost of the control plate  6  increases. Moreover, the gap between the control plate  6  and the separating weir  1  is reduced, and a problem occurs that contaminants are caught therebetween. 
     If the arrangement position Y exceeds 1.5 D, the position where the vortex is generated becomes too far from the opening portion  3   a  of the intercepting pipe  3  to draw contaminants into the intercepting pipe  3 . If the arrangement position Y is less than 0.83 D or 1.0 D, there poses such a problem that contaminants are caught between the control plate  6  and the inner wall surface of the storm overflow chamber  10  to which the intercepting pipe  3  opens. 
     If the water level of the inflow water exceeds the top end of the separating weir  1 , the water surface bulges upward near the guide wall  7 , and a water surface gradient from the inflow pipe  2  to the separating weir  1  is not formed. As a result, contaminants flow along the guide wall  7 , and are guided to the neighborhood of the opening portion  3   a . The guided contaminants are drawn into the vortex generated with the control plate  6 , and then flow into the intercepting pipe  3 , resulting in an increased efficiency of drawing contaminants.