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DAF Sizing Calculator

Preliminary dissolved air flotation design calculations based on your wastewater flow, solids loading, temperature, and application type. Includes salinity compensation and saturator sizing.

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DAF Sizing Calculator

Preliminary design calculations based on your wastewater characteristics

How the Calculator Works

1. Air Solubility Interpolation

Linear interpolation from standard APHA/AWWA tables (5°C–40°C) gives baseline dissolved air at 1 atm. Salinity and pressure corrections applied.

2. Wastewater Characterisation

COD, FOG, and TSS inputs drive realistic A/S ratios and removal expectations. Dairy and high-FOG streams get conservative hydraulic loadings.

3. Tank Geometry & Depth

Surface area converts to actual footprint (rectangular or circular). Depth derives from target HRT, freeboard, and sludge collection zone.

4. Recycle & Solids Loading

A/S ratio determines recycle flow: QR = (A/S Ɨ Q Ɨ TSS) / Ca. Solids loading rate verifies the design against industry limits.

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Calculator Inputs & Sensitivity

The DAF sizing calculator works from six inputs. Understanding their sensitivity helps interpret results.

Inlet Flow (Q)

Average and peak forward flow in m³/h. Peaking factor 1.5–2.5 for industrial diurnal cycles; 1.2–1.5 for steady-state continuous processes.

Inlet Solids (TSS)

Influent TSS concentration in mg/L. Drives solids load. If unknown, use 200–500 mg/L for municipal-style, 500–3,000 for industrial-organic, 200–800 for petrochem.

Target A/S Ratio

0.005–0.06. Use 0.01–0.02 default; 0.025–0.04 for oily; 0.005–0.01 for sludge thickening. Higher A/S → higher recycle → larger pump/saturator.

Saturator Pressure

Default 5 bar. Higher pressure reduces recycle ratio (smaller pump) but raises pressure-vessel cost. Validation: optimise against fleet experience.

Hydraulic Loading

Surface area output. 4–6 m/h for industrial; 6–10 m/h for municipal; 8–12 m/h for algal/WT. Manipulating HLR explores compact vs conservative designs.

Saturator Efficiency

Packed: 75–85%; cyclonic: 90–95%. Higher efficiency reduces recycle ratio. Calculator output is sensitive to this — use field-verified value from manufacturer.

Need a Performance-Guaranteed DAF Design?

Our engineers validate calculator estimates with jar testing, pilot trials, and CFD analysis. Reynolds & Bauhm provides contractual effluent guarantees backed by 30+ years of DAF experience.

Industries We Serve

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