Perda de carga em grades de esgoto
Downflow
Upflow

Input data

Flow

Width (b)

Trashrack width (W)

Distance between trashracks (d)

Downflow level (y)

Slope (º)

β - Kirschmer

Output data

Upflow level

Upflow velocity

Energy

Velocity between bars

Head loss

Upflow level at 50%

Upflow velocity at 50%

Velocity between bars at 50%

Upflow energy at 50%

Head loss at 50%

Description

Given the flow, channel geometry, and screen characteristics, this tool calculates the downflow water level if the upflow water level is known, or the upflow water level if the downflow water level is known. This is particularly useful in wastewater systems where trash racks are used to remove solids.

Head Loss in Sewer Trash Racks Image

Available Calculation Methods

1. Downflow

Calculates the upflow water level, velocity, and energy, considering the known downflow water level.

Inputs:

ParameterUnitDescription
Flow (Q)m³/sInlet flow
Width (b)mWidth of the channel
Trashrack width (W)mThickness of the trashrack
Distance between trashracks (d)mSpacing between the trashracks
Downflow level (y)mWater level at downflow
Slope (º)-Slope angle of the trashrack
β - Kirschmer-Kirschmer coefficient

Outputs:

ParameterUnitDescription
Upflow level (ym)mWater level at upflow
Upflow velocity (Um)m/sFlow velocity at upflow
Energy (Em)JEnergy at the upflow
Velocity between bars (Ubb)m/sFlow velocity between bars
Head loss (Hl)mHead loss in the system

2. Upflow

Calculates the downflow water level, velocity, and energy, considering the known upflow water level.

Inputs:

ParameterUnitDescription
Flow (Q)m³/sInlet flow
Channel width (b)mWidth of the channel
Trashrack width (W)mThickness of the trashrack
Distance between trashracks (d)mSpacing between the trashracks
Upflow level (ym)mWater level at upflow
Slope (º)-Slope angle of the trashrack
β - Kirschmer-Kirschmer coefficient

Outputs:

ParameterUnitDescription
Downflow level (y)mWater level at downflow
Downflow velocity (U)m/sFlow velocity at downflow
Energy (E)JEnergy at the downflow
Velocity between bars (Ubb)m/sFlow velocity between bars
Head loss (Hl)mHead loss in the system

References

  • WEF, ASCE, EWRI (2010). Design of municipal wastewater treatment plants. Volume 2: liquid treatment processes. New York, McGraw Hill.