{"id":7786,"date":"2020-06-23T15:55:16","date_gmt":"2020-06-23T13:55:16","guid":{"rendered":"http:\/\/www.hydrograv.com\/?page_id=7786"},"modified":"2024-01-11T13:25:12","modified_gmt":"2024-01-11T12:25:12","slug":"secondary-clarifiers","status":"publish","type":"page","link":"https:\/\/www.hydrograv.com\/en\/services\/simulation\/secondary-clarifiers\/","title":{"rendered":"Secondary Clarifiers"},"content":{"rendered":"
\n

Simulation of Secondary Clarifiers<\/span><\/strong><\/span><\/p>\n

What are the benefits of hydrograv simulations?<\/span><\/strong><\/span><\/p>\n

    \n
  • higher capacity: With an optimized inlet design above the limits of design guide lines, e. g. the German DWA-A 131<\/li>\n
  • maximum security against sludge overflow<\/li>\n
  • maximum effluent quality (SS, Ptot<\/sub>, COD) by optimized inlet design<\/li>\n
  • maximum use of the tank\u2019s depth by optimized effluent design<\/li>\n
  • optimization of operational strategy, e. g. RAS, sludge displacement<\/li>\n
  • optimal function of the scraper system<\/li>\n
  • determination of the flocculation potential<\/li>\n<\/ul>\n

    What we offer:<\/strong><\/span><\/p>\n

      \n
    • maximum predictability based on measurements of sludge concentrations on site in the settling tanks<\/li>\n
    • extensive data analyses to obtain representative loadings and for evaluation of the simualtion results<\/li>\n
    • extensive studies of design variants, operational strategies and optimizations
      \n<\/strong><\/li>\n<\/ul>\n

      What are the features?<\/strong><\/span><\/p>\n

        \n
      • two and threedimensional multiphase simualtios<\/li>\n
      • simulation of the sludge displacement between aeration und secondary clarifier<\/li>\n
      • realistic modelling of different scraper systems and sludge properties<\/li>\n<\/ul>\n

        Example 1: Measurement of the sludge concentration and validation of the simulation models
        \n<\/span><\/strong><\/span><\/p>\n

        \"\"<\/p>\n

        Figure:\u00a0\u00a0 <\/strong>Distribution of the sludge concentratin in a circular tank.
        \n<\/span><\/p>\n

        \u00a0\"\"<\/strong><\/p>\n

        Figure:\u00a0\u00a0 <\/strong>Comparison between measurement (points) and simulation (red line) of flow velocities from Armbruster (2004).
        \n<\/span><\/p>\n

        ..<\/span>
        \nExample 2: Determination of representative loadings with proload.data
        \n<\/span><\/strong><\/span><\/p>\n

          \n
        • extensive data analysis with hydrograv data analysis software proload.data, e. g. QWWTP<\/sub>, QRAS<\/sub>, SVI, MLSS, SS, Ptot<\/sub>, COD<\/li>\n
        • simulation verification for high, average und low loadings and optimization of a best possible inlet design for all loading cases<\/li>\n<\/ul>\n

          \"\"<\/p>\n

          Figure:\u00a0\u00a0 <\/strong>Two dimensional statistical analysis of the sludge volume considering the MLSS and the SVI.
          \n<\/span><\/p>\n

          \u00a0<\/span><\/p>\n

          Examle 3: Automatic optimization of the inlet design
          \n<\/span><\/strong><\/span><\/p>\n

            \n
          • simulation with representative average sludge volumen for dry weather and stormwater flow<\/li>\n
          • determination of a best possible compromise of the inlet height and the opening height of a fixed inlet construction considering the individual operational strategy of the WWTP<\/li>\n<\/ul>\n

            \"\"\"\"<\/span><\/p>\n

            Figure:\u00a0\u00a0 <\/strong>Sludge concentration and automatic adapted inlet geometry (inlet height and opening height) for representative average sludge volume for dry weather flow\u00a0 (above) and storm water flow (below).<\/span><\/p>\n

            \"\"<\/p>\n

            Figure:\u00a0\u00a0\u00a0<\/strong>Determination of a best fitting fixed compromise inlet height.<\/p>\n

            Example 4: Determination of the maximum capacity<\/span><\/strong><\/span><\/p>\n

              \n
            • e.g. capacity\u2019s increase of 25 % by optimized inlet design<\/li>\n
            • e.g. loading exceeds 40 % the limits of the design guideline DWA-A 131 (see figure)<\/li>\n<\/ul>\n

              \"\"<\/p>\n

              Figure:\u00a0\u00a0 <\/strong>Sludge concentration in a secondary clarifier with height adaptive inlet system.
              \n<\/span><\/p>\n

              \"\"<\/p>\n

              Figure:\u00a0\u00a0 <\/strong>Determination of the maximum SVI for different inlet designs. Comparision between the status quo, a fixed optimization with two inlet heights und a height varialbe inlet design with two diameters.
              \n<\/span><\/p>\n

              .<\/span>
              \nExample 5: Improvements of the effluent quality<\/strong>
              \n<\/span><\/strong><\/span><\/p>\n

              minimization of unstable sludge bed areas (ineffective Zone) = minimization of sludge flocs in the supernatant<\/p>\n

              \"\"<\/p>\n

              \"\"<\/p>\n

              Figure: \u00a0 <\/strong>Categorisation of the sludge bed into functional zones. The green zone represents diluted unstable areas of the sludge bed. Above: Status quo. Below: Optimization.
              \n<\/span><\/p>\n

              .<\/span><\/p>\n

              Example 6: Optimization of geometric details \u2013 inlet design
              \n<\/span><\/strong><\/span><\/p>\n

              \"\"<\/p>\n

              Figure: \u00a0 <\/strong>3D-simulation of a inlet structure and analysis of the hydraulic distribution at the inlet opening.
              \n<\/span><\/p>\n

              .<\/span><\/p>\n

              Example 7: Verification of the flocculation potential<\/span><\/strong> \"\"<\/p>\n

              Figure:\u00a0\u00a0 <\/strong>3D-simulation of a inlet structure and analysis of the G-value.<\/p>\n

              .<\/span><\/p>\n

              Example 8: Optimization of a suction scraper
              \n<\/strong><\/p>\n

                \n
              • in status quo unsufficient hydraulic capacity of the suction scraper system<\/li>\n
              • with optimization higher hydraulic capacity by optimization of different components<\/li>\n<\/ul>\n

                \"\"<\/p>\n

                Figure:\u00a0\u00a0 <\/strong>Detailed 3D-simulation of a suction scraper system and determination of hydraulic losses.
                \n<\/span><\/p>\n

                \"\"<\/p>\n

                Figure:\u00a0\u00a0 <\/strong>Detailled 3D-simulation of a lifting pipe.
                \n<\/span><\/p>\n

                .<\/span><\/p>\n

                Example 9: Verification of a rotation suction scraper system
                \n<\/strong><\/p>\n

                  \n
                • simulation of a rotating suction scraper system to study the impact of the sludge removal on the effluent quality<\/li>\n<\/ul>\n

                  \"\"<\/p>\n

                  Figure:\u00a0\u00a0 <\/strong>Detailled 3D-simulation of a rotating suction scraper system. Sludge level during dry weather loading.
                  \n<\/span><\/p>\n

                  \"\"<\/p>\n

                  Figure:\u00a0\u00a0 <\/strong>Detailled 3D-simulation of a rotating suction scraper system. Velocities close to the bottom during dry weather loading.
                  \n<\/span><\/p>\n<\/div><\/section><\/div><\/div><\/div><\/main><\/div><\/div>