{"id":7861,"date":"2020-06-23T17:06:48","date_gmt":"2020-06-23T15:06:48","guid":{"rendered":"http:\/\/www.hydrograv.com\/?page_id=7861"},"modified":"2022-07-07T09:42:28","modified_gmt":"2022-07-07T07:42:28","slug":"grit-chambers","status":"publish","type":"page","link":"https:\/\/www.hydrograv.com\/en\/services\/simulation\/grit-chambers\/","title":{"rendered":"Grit Chambers"},"content":{"rendered":"
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Simulation of Grit Chambers<\/span><\/strong><\/span><\/p>\n

What are the benefits of hydrograv simulations?<\/strong><\/span><\/h3>\n
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  • Maximization of removal rates of grit particles and grease<\/li>\n
  • Minimization of construction costs by efficiency increase (e.g. less construction volume)<\/li>\n
  • Minimization of operational costs by optimization of the aeration<\/li>\n
  • Determination of dynamic forces on installations
    \n\u00a0<\/strong><\/strong><\/strong><\/li>\n<\/ul>\n

    Example 1: Calibration and validation of the simulation models for aerated grit chambers
    \n<\/span><\/strong><\/span><\/h4>\n
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    • Measurements of the 3D-velocity by a high resolution acustic probe<\/li>\n
    • Calibration and validation of model approaches, e.g. turbulence model, bubble size<\/li>\n<\/ul>\n

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

      Figure:<\/strong> Comparison of measured and simulated water velocities in the grit and grease basin of an aerated grit chamber.
      \n<\/span><\/p>\n

      Example 2: Streamlines visualize the flow patterns
      \n<\/span><\/strong><\/span><\/h4>\n
        \n
      • Streamlines visualize the path of the flow and show areas with hydraulic deficits, e.g. short-circuit flow.<\/li>\n<\/ul>\n

        \"\"<\/p>\n

        Figure:<\/strong> Streamlines with velocities vizualize the flow patterns.<\/p>\n

        Example 3: Investigation of geometrical changes<\/strong><\/p>\n

          \n
        • for example, investigation of the impact of a separation baffle between grit and grease basin<\/li>\n
        • deterministic analysis of the removal rate of grit and grease<\/li>\n<\/ul>\n

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

          \"\"<\/p>\n

          Figure:<\/strong> Aerated grit chamber with lamellae as a separting wall between grit and grease basin.
          \n<\/span><\/p>\n

          \"\"<\/p>\n

          Figure:<\/strong> Aerated grit chamber without lamellae as a separting wall between grit and grease basin.<\/span>
          \n.<\/span><\/p>\n

          Example 4: Verification of separation rates
          \n<\/strong><\/h4>\n
            \n
          • simulation of test sand according to the German Association for Water, Wastewater and Waste, DWA (2008): Arbeitsbericht des DWA-Fachausschusses KA-5 \u201eAbsetzverfahren\u201c. Sandf\u00e4nge \u2013 Anforderungen, Systeme und Bemessung. Korrespondenz Abwasser, Abfall 5\/2008. S. 508 \u2013 518.<\/li>\n
          • Investigation of different classes of materials: sand, grease, organic substances<\/li>\n<\/ul>\n

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

            Figure:<\/strong> Grain distribution of sand. Left: at the inlet of the grit chamber. Right: Comparison between inlet and outlet of the grit chamber. Mesh width logarithmic.
            \n<\/span><\/p>\n

            \"\"<\/p>\n

            Figure:<\/strong> Separation rate of different classes of materials.
            \n<\/span><\/p>\n

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

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

            Example 5: Verification of dynamic forces
            \n<\/span><\/strong><\/h4>\n
              \n
            • Determination of the hydrodynamic pressure on the basis of the flow velocity on the total surface of a separating wall pipes and determination of the force acting therefrom<\/li>\n<\/ul>\n

              \"\"<\/p>\n

              Figure:<\/strong> Dynamic forces acting on separating wall pipes between grit and grease basin.
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