UK HQ Your time
ClientUK Regional Craft BreweryApplicationDAF — Brewery Wastewater Pretreatment
Document RefRB-CS-DAF-001DateApril 2026
Key ResultTSS Removal 78% → 94%chemical reduction62% ferric chloride reduction

1. Executive Summary

A UK craft brewery operating a 50,000 hl/year facility experienced suboptimal solids removal in their existing Dissolved Air Flotation (DAF) system. Despite operating within conventional design loading parameters (10 m/h hydraulic loading, 0.03 A/S ratio), TSS removal remained at 78% — insufficient to protect downstream advanced biological treatment from organic overload and prevent sewer discharge surcharge penalties.

Reynolds & Bauhm conducted a comprehensive Computational Fluid Dynamics (CFD) analysis of the DAF contact and separation zones. The simulation revealed a severe white water distribution maldistribution (uniformity index 0.61) causing a central high-velocity jet and corner stagnation zones. This hydraulic short-circuiting reduced effective bubble-floc contact time by 52%.

Through CFD-guided design modifications — manifold re-orificing, deflection baffle addition, and contact zone geometry adjustment — the brewery achieved validated performance improvements:

MetricBaselineOptimisedImprovement
TSS Removal78%94%+16 percentage points
Contact Time Uniformity (COV)0.480.1275% more uniform
White Water Distribution Uniformity Index0.610.91+49% improvement
Ferric Chloride Consumption85 mg/L32 mg/L62% reduction
Sludge Volume Index185 mL/g112 mL/gImproved settleability
Downstream Biological Overload Incidents3-4/month0Eliminated

2. Client Background & Problem Statement

Facility: 50,000 hl/year craft brewery with on-site effluent treatment

Existing Treatment Process: Screening → EQ Tank → DAF (2-cell) → Aerobic SBR → Discharge to sewer

Influent Characteristics:

3. CFD Methodology

Software: ANSYS Fluent 2024 R1 with Eulerian multiphase model

Model Configuration:

CFD Simulation Results — Velocity Contours

Baseline (left) vs. Optimised (right) contact zone velocity distribution. Note the elimination of the central high-velocity jet and corner stagnation zones.

4. Key Findings

Critical Finding: White Water Maldistribution

The CFD analysis revealed that the existing manifold design created a preferential flow path to the centre of the contact zone, with 40% of white water exiting through just 15% of the nozzle area. This created a high-velocity central plume (0.35 m/s) that short-circuited directly to the outlet, while corners experienced near-stagnant conditions (<0.02 m/s) with excessive contact time.

5. Design Modifications

ModificationDescriptionImpact
Manifold Re-OrificingRedistributed nozzle sizes from uniform 8mm to tapered 6-10mm patternUniformity index 0.61 → 0.91
Deflection BaffleAdded 45° angled baffle 200mm below manifoldEliminated central jet, improved lateral distribution
Contact Zone ExtensionIncreased contact zone depth from 1.2m to 1.5m+25% contact time, improved floc-bubble aggregation
Outlet Weir ModificationV-notch weir replaced with submerged perforated outletReduced surface velocity, eliminated dead zones

6. Validation & Performance

Post-modification performance was validated over a 3-month operational period. The brewery confirmed sustained TSS removal of 92-95% across varying loading conditions, with no downstream biological overload incidents. Chemical consumption was monitored via automated dosing records.

7. Related Applications

Discuss Your DAF ApplicationBook Pilot Testing

Need CFD Analysis for Your DAF System?

Reynolds & Bauhm CFD engineers can diagnose hydraulic issues in your contact zone, identify short-circuiting, and validate design modifications before capital investment. Contact us to discuss your application.

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