Recommendations
Triangular weirLamellar settling modulesSettling tank: hydraulic superficial loading rateRectangular section troughSludge removal device for settling tank (BIOWASSERTRACK®)Circular primary decanter for conventional ETE
Lamellar settling tank: settled water collection
Settled water trough calculation

Input data

Water temperature

Incoming flow

Number of settling tanks in parallel

Trough width (b)

Trough height (h)

Trough length (L)

Number of sides from which settled water is collected

Number of troughs per settling tank

Output data

Flow per length of collected settled water:

Estimated number of triangular weirs for collecting settled water

Water height in each triangular weir (according to Thomson's formula)

Maximum water height in the trough

Free height over maximum level

Critical height at the trough outlet (hc)

Description

Calculate the capacity of lamellar settling tanks from their inlet flow and geometry.


Note: This calculation assumes that the troughs have free discharge. For submerged discharges, use the following calculation: https://voimatoolbox.com/en/calculations/rectangular-section-trough

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.