Patent Publication Number: US-7717275-B2

Title: Integrated perforated flocculating baffle system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
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   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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   THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
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   INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A CMPCAT DISC 
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   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a system of integrated perforated flocculating baffles for use in solids separation and settling tanks, the baffle system consisting of a plurality of interconnected perforated baffles attached to and forming a flocculation compartment. 
   2. Description of the Related Art 
   The present invention relates to a system of baffles for a tank for separation of solids from the water by gravitational forces in water and wastewater treatment. The tank where the inventive system of baffle device is used is typically circular, square or rectangular in shape. 
   In water and wastewater treatment where sedimentation tanks, also known in the art as clarifiers or settling tanks, are used, the efficiency of the tanks is governed by the amount of suspended matter removed. Density currents resulting from the difference in specific gravity between suspended matter and water or the differential temperature between the atmosphere and the water contained in the tank represent a major deterrent to the tank removal efficiency. Density difference creates strong currents and hydraulic short circuiting within the tank reducing the effective volume available for flocculation and settling of the suspended matter and re-suspends the settled solids. To enhance hydraulics regime and flocculation within the tank, several types of feedwells (also known as center wells) have been developed over the years mainly for circular clarifiers. 
   Representative examples of prior art of feedwells and the like are disclosed in U.S. Pat. No. 2,702,124 to Stengel, U.S. Pat. No. 3,175,692 to Edgerton, U.S. Pat. No. 3,486,628 to Darby, U.S. Pat. No. 3,966,617 to Zaenkert, U.S. Pat. No. 4,270,676 to Green, U.S. Pat. No. 4,985,148 to Monteith, U.S. Pat. No. 5,378,378 to Meurer, U.S. Pat. No. 5,384,049 to Murphy, U.S. Pat. No. 5,714,068 to Brown, U.S. Pat. No. 6,099,743 to Pederson, U.S. Pat. No. 6,276,537 to Esler and U.S. Pat. No. 6,800,209 to Wright. All of these feedwells and energy dissipating inlet designs emphasized the importance of dissipating the energy of the incoming water as means for improving flocculation. None of these prior art feedwells or energy dissipating inlets was designed to reduce or eliminate the currents produced by difference in specific gravity between suspended solids and water or the differential temperature between the atmosphere and the water contained in the clarifier. In addition, many of these prior art feedwells and energy dissipating inlets are limited in application to certain configuration of clarifiers. Moreover, no prior art reference discloses a plurality of interconnected individual perforated baffles with each baffle including a linear solid and curved sections followed by open sections, supported on the top to a structural element. 
   It is, therefore, an object of the present invention to provide a system of plural, interconnected baffles, curved to match the peripheral contour of the circular feedwell in case of a circular tank or, alternatively, linear to match the supporting structure in case of a non-circular tank, forming a rigid wall of perforated baffle system extending downward inside the tank. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides an integrated perforated flocculating baffle system designed to satisfy the aforementioned need. The integrated perforated flocculating baffle system of the present invention both enhances flocculation and reduces the adverse effect of the solids-induced or thermal-induced density currents by eliminating flow entrainment from the main settling zone of the clarifiers into the flocculation zone and providing nearly uniform flow through its perforated surface. 
   The present invention presents an interconnected baffle system forming a rigid wall of perforated baffles allowing incoming water to pass through its openings promoting flocculation of the suspended matter, and distributing the flow equally and uniformly throughout the settling zone of the clarifiers. The baffle system includes a plurality of interconnected perforated baffles curved to match the peripheral contour of the circular feedwell in case of a circular clarifier or, alternatively, linear to match the supporting structure in case of a non-circular tank. The baffle system divides the clarifier into two compartments; one before and one after the baffle system. The compartment before the baffle system is for flocculation of the suspended matter and dissipating the energy of the incoming water, and the compartment after the baffle system is for settling of suspended matter. Each baffle includes linear solid and curved sections followed by perforated sections. Baffles are secured on the top to the feed well, in case of a circular clarifier, and a supporting beam, in case of a non-circular clarifier in a curtain-like fashion. The baffles are interconnected along the length by cross connectors to ensure rigidity. 
   In a currently preferred implementation, the individual baffles are fabricated from a molded reinforced fiberglass composite as one piece. Thus, each molded baffle incorporates the linear and curved solids sections and perforated sections. Most preferably, the thickness of the fiberglass panels is in the range from 3/16 th  to ½ th  of an inch, a range that provide structural integrity to the whole baffle system. 
   The features and advantages of the present invention will become apparent to those skilled in the art upon reading of the following detailed description when taken in conjunction with the drawings where there is shown an illustrative embodiment of the invention and the claims where there is indication of the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following detailed description, reference will be made to the attached drawings in which: 
       FIG. 1  is a perspective view of an integrated perforated flocculating baffle system of the present invention mounted to a support beam in rectangular clarifier. 
       FIG. 2  is a detailed view of the individual baffle. 
       FIG. 3  is a cross section through the solid portion of the baffle. 
       FIG. 4  is a cross section through the perforated portion of the baffle. 
       FIG. 5  is a detailed view of the cross connectors the baffles along the length. 
       FIG. 6  is a partial plan view of an integrated perforated flocculating baffle system in a non-circular tank. 
       FIG. 7  is a cross section view of an integrated perforated flocculating baffle system in a circular tank. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings and particularly to  FIG. 1 , there is illustrated an integrated perforated flocculating baffle system, generally designated  10 , of the present invention, which is mounted to a support beam  40 , in a rectangular clarifier tank  30 . Basically, the integrated baffle system  10  includes individual baffles  12 , and cross connectors  14 . 
   Referring to  FIG. 2 , detailed view of the individual baffle  12  is shown. Each baffle consists of a linear solid section  16 , curved sections  18  and open sections  20 . The width, length and thickness of individual baffle  12  are functions of the size, shape and type of the clarifier. Generally, the width of the individual baffle ranges between 6 inches to 96 inches. Mounting holes  22  to support individual baffles from support beam  40  are drilled in the linear solid section  16 . 
   Referring to  FIG. 3 , the size of the linear solid section  16  is a function of the size of baffle  12 . Generally, the length of linear sound section  16  ranges between 6 inches to 60 inches. The thickness of linear solid section  16  could be 3/16 th  of an inch thick to provide more rigidity to the baffle system  10 . The shape of curved sections  18  depends on the characteristics of the water passing through the baffle. Radial angle for the curved section  18  could range from 180 degrees (half circle) to 90 degrees. 
   Referring to  FIG. 4 , the length of the open section  20  ranges between 2 inches to 32 inches depending on the characteristics of the incoming water and suspended matter. 
   Referring to  FIG. 5 , the cross connector  14 , in one embodiment, includes a cable clamp and stainless steel washer  24 . 
   Referring to  FIG. 6 , the integrated baffle system  10  in the rectangular clarifier tank  30  is shown in plan view. As noted above, the integrated baffle system  10  includes individual baffles  12  mounted to a support beam  40  within the clarifier tank  30  with cross connectors  14  between the individual baffles. 
   Referring to  FIG. 7 , the integrated baffle system  10  with individual baffles  12  and cross connectors  14  is shown as being mounted to a feed well  50  in a circular clarifier tank  60 .