Aeff=N⋅Ap⋅cos(θ)cap A sub e f f end-sub equals cap N center dot cap A sub p center dot cosine open paren theta close paren = Total number of lamella plates Apcap A sub p = Area of a single plate (Length m2m squared = Angle of inclination (typically 55∘55 raised to the composed with power 60∘60 raised to the composed with power relative to the horizontal plane) Surface Overflow Rate (
Plate area: 1.25 m × 2.5 m = 3.125 m² N = 13.9 m² / 3.125 m²/plate ≈ 4.45 plates
| Parameter | Symbol | Typical Range | |-----------|--------|----------------| | Surface Overflow Rate (SOR) | SOR | 0.5 – 2.5 m³/m²·h | | Plate spacing | d | 25 – 75 mm | | Plate inclination | θ | 50° – 60° from horizontal | | Plate length | L | 1 – 2.5 m | | Flow velocity between plates | v | < 0.3 m/min (laminar flow) | lamella clarifier design calculation pdf downloadl better
The efficiency of a clarifier is not dependent on its depth, but on its . Lamella clarifiers exploit this by stacking plates at an angle (usually 55° to 60°). This creates multiple "false bottoms," effectively multiplying the settling area ( Aeffcap A sub e f f end-sub The Mathematical Foundation: The basic equation for settling is:
Feed water must enter evenly across the entire width of the plate pack. Uneven distribution creates preferential flow paths (channeling), causing localized high velocities that disrupt settling. Aeff=N⋅Ap⋅cos(θ)cap A sub e f f end-sub equals
) equipped with automated blowdown valves to prevent sludge compaction and septicity.
Ar=QSORcap A sub r equals the fraction with numerator cap Q and denominator cap S cap O cap R end-fraction : Design Flow Rate ( SORcap S cap O cap R : Surface Overflow Rate ( 2. Calculate Effective Area per Plate ( Apcap A sub p Calculate Effective Area per Plate ( Apcap A
) within a small physical space. This is based on , which states that settling efficiency depends on surface area rather than tank volume or depth. Key Parameters: Plate Angle ( ): Typically 55∘55 raised to the composed with power 60∘60 raised to the composed with power
Using these mathematical relationships ensures precise sizing of the clarification equipment, optimizing suspended solids removal while safeguarding against structural and process vulnerabilities.
): Reduces the effective horizontal settling area, requiring more plates. Too shallow (