Calculations
Recommendations
Centrifugal Decanter (Pieralisi)Lamellar settling modulesWashing water collector gutterWell-rounded inletVelocity gradient to Parshall meterHead loss in the filter bed during washingFlocculated water distribution under plates
Input data
Water temperature
Incoming flow
Number of settling tanks in parallel
Distribution duct upstream internal height (hu)
Distribution duct internal width (b)
Distribution duct downstream internal height (hd)
Roughness of pipe inner surface
Number of distribution tees (both sides)
Distribution tee diameter (D)
Output data
Upstream velocity in the distributor
Upstream velocity gradient
Downstream velocity in the distributor
Downstream velocity gradient
Velocity in the distribution tees
Velocity gradient in the distribution tees
Description
This calculation determines the outlet velocities and velocity gradients in distribution ducts, considering the inlet flow and system geometry.
Distribution ducts
Input and Output Parameters
Inputs
Parameter | Standard Units | Description |
|---|---|---|
Water temperature (TC) | °C | Water temperature in the system |
Incoming flow (Q) | L/s | Flow rate entering the distribution system |
Number of settling tanks in parallel (N) | - | Number of settling tanks operating simultaneously |
Distribution duct upstream internal height (hu) | m | Internal height of the upstream distribution duct |
Distribution duct internal width (b) | m | Internal width of the distribution duct |
Distribution duct downstream internal height (hd) | m | Internal height of the downstream distribution duct |
Roughness of pipe inner surface (k) | mm | Roughness of the internal pipe surface |
Number of distribution tees (Ntee) | - | Total number of distribution tees |
Distribution tee diameter (Dtee) | mm | Internal diameter of the distribution tees |
Outputs
Parameter | Standard Units | Description |
|---|---|---|
Upstream velocity in the distributor (vu) | m/s | Water velocity in the distribution duct before distribution |
Upstream velocity gradient (Gu) | s⁻¹ | Velocity gradient in the upstream duct |
Downstream velocity in the distributor (vd) | m/s | Water velocity in the distribution duct after distribution |
Downstream velocity gradient (Gd) | s⁻¹ | Velocity gradient in the downstream duct |
Velocity in the distribution tees (vtee) | m/s | Water velocity in the distribution tees |
Velocity gradient in the distribution tees (Gtee) | s⁻¹ | Velocity gradient in the distribution tees |
References
- ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS – ABNT. (1992). NBR 12216 - NB-592 “Projeto de estações de tratamento de água para abastecimento público” ABNT, Rio de Janeiro, Brasil.