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Sedimentation & Clarification

Gravity and high-rate settling for suspended-solids and coagulated-floc removal — from classical clarifier theory to inclined-plate lamella units — engineered to the surface overflow rate your solids demand.

Settling Regimes & Overflow Rate

Four settling regimes govern clarifier behaviour and sizing

Discrete & Flocculent Settling

Type I (discrete) and Type II (flocculent) settling describe dilute suspensions where particles settle independently or coalesce as they fall.

Hindered & Compression

Type III (hindered/zone) and Type IV (compression) settling govern concentrated sludges where particles interact and consolidate.

Surface Overflow Rate

The governing design variable is the surface overflow rate (q = Q/A); a particle is captured only if its settling velocity exceeds q, independent of tank depth.

Hazen Theory — Why Plate Area, Not Depth, Governs Capture

Ideal-basin (Hazen) theory shows that removal efficiency depends on the ratio of particle settling velocity to surface overflow rate, vs/q, and is independent of tank depth. This is the principle exploited by lamella clarifiers: stacking inclined plates multiplies the projected settling area A within a fixed footprint, so the effective overflow rate falls and fine particles are captured — delivering up to a 10-fold area increase versus an open tank.

Clarification Technologies

Matched to solids concentration, floc character and footprint

Conventional Clarifiers

Circular and rectangular gravity clarifiers handle high flows and high-solids primary and secondary duties.

Lamella (Inclined-Plate)

Inclined-plate packs at 55–60° provide a large settling area in a compact unit; sludge slides to the hopper while clarified water rises.

Ballasted & High-Rate

Ballasted and solids-contact systems accelerate settling for difficult, slow-settling floc.

Getting Clarification Right

Coagulation Upstream

Fine and colloidal solids must be coagulated and flocculated before settling to form a settleable floc.

Plate Spacing & Angle

Spacing (50–100 mm) and angle (55–60°) balance capture, blinding risk and self-cleaning sludge slide.

Sludge Removal

Reliable sludge collection and withdrawal prevent re-suspension and maintain clarified-water quality.

Designing a clarifier or lamella stage?

Reynolds & Bauhm engineers sediment-removal trains from grit chambers to colloidal polishing, matched to your particle-size distribution and discharge consent.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.