Engineering Tool · Tanks & Basins

DAF Designer

Screen dissolved-air flotation recycle hydraulics, loading, released-air mass, air-to-solids ratio, and contact time.

Municipal Drinking WaterStage 03 — Clarification & Filtration

Status: Available

PROJECT · OPTIONAL

Project metadata

Report context for exports; it does not change calculations.Edit detailsHide details

Project optionalFacility optionalPrepared by optionalRevision optionalNotes optional

01 · USER INPUT

Design basis and inputs

Raw flow *m³/d · flow before recycleActive cell count *cells · identical parallel separation cellsSurface area per cell *m² · active plan areaRecycle ratio *fraction of raw flow · Qr = R × raw flow; 0.10 = 10% of raw flowEffective released-air concentration *mg/L recycle · user-entered released-air concentration in recycle streamSolids loadkg/d · optional user-entered captured or target solids mass basisContact/separation volumem³ · optional user-entered volume for nominal contact-time screeningTarget contact timemin · optional minimum project contact-time criterion

Engineering calculations run locally in this browser after assets load.

02 · CALCULATED RESULT

Results at a glance

Load or enter inputs, then calculate to create an authoritative result.

03 · REPORTING

Exports and verification

CSV contains input and output detail. PDF uses the current calculation and report metadata.

Verification suite

Calculation revision 22463161

59 focused fixtures: independent recycle, hydraulic loading, air-mass, air-to-solids, and contact-time cases; numerical boundaries, criterion comparison, and input rejection. Tests are deterministic and run without network access.

Engineering Basis

Methodology

Separates raw flow from recycle flow for hydraulic loading, then derives released-air mass and air-to-solids ratio from entered recycle, air concentration, and solids basis. Contact time is a nominal volume/flow screen, not residence-time distribution or a removal guarantee.

Recycle flow = recycle fraction × raw flow. Total hydraulic flow includes raw plus recycle.

Raw-flow surface loading uses raw flow; total hydraulic loading uses raw flow plus recycle flow.

Released-air mass = recycle flow × user-entered effective released-air concentration, with mg/L converted to kg/m³. Air-to-solids ratio = released-air mass / entered solids mass basis.

Contact-time screening uses raw flow plus recycle flow through the entered contact/separation volume. Calculated contact time = volume / total hydraulic flow.

Scope / Limitations

Calculate recycle flow, raw and total hydraulic loading, released air and A/S from declared inputs, with optional solids and contact-volume criteria.
Calculated hydraulic contact time is a nominal volume/flow screening value and does not represent actual residence-time distribution.
Effective released-air concentration is user-entered. This version does not derive saturator performance from pressure, temperature, or Henry law.
The air-to-solids ratio is a design-basis ratio and is not an adequacy, optimization, or solids-removal guarantee.
This screening tool does not predict bubble size, perform CFD, select recycle pumps, or guarantee solids-removal performance.

Engineering Path

Upstream Context

Coagulation & Flocculation Designer Use source-water conditions and declared jar-test criteria to inform the first separation choice.

Current Tool Decision

DAF Designer Screen dissolved-air flotation recycle hydraulics, loading, released-air mass, air-to-solids ratio, and contact time.

Downstream Engineering Step

Granular Media Filter Designer Where filtration follows clarification or flotation, carry the selected solids and flow basis into filter loading and headloss review.