SS304/316L Multiple Effect Evaporation System for Dye Wastewater — Ammonium Sulfate Recovery
Hanpu designs Multiple Effect Evaporation (MEE) plants in SS304/SS316L specifically for dye & dye-intermediate wastewater. The system concentrates sulfate-rich streams and integrates vacuum crystallization to recover ammonium sulfate (AS) as a reusable salt, cutting disposal cost and enabling ZLD/near-ZLD compliance with optimized OPEX.
Engineered Materials
Product-wetted parts in SS316L for corrosive, colored liquors; structural and utility lines in SS304 for value optimization. Elastomers and gaskets matched to pH and solvent exposure.
Color & Organics Tolerance
Stable low-ΔT operation and high-shear distribution reduce fouling; optional decolorization or carbon polishing can be integrated upstream.
Ammonium Sulfate Payback
Concentrated mother liquor feeds the vacuum crystallizer to produce marketable AS crystals with controlled particle size for storage and sale.
Process Overview
- Feed Conditioning: Screening/filtration, pH trim, anti-scalant, and optional defoamer to stabilize dye effluent.
- Multi-Effect Evaporation: Live steam heats Effect-1; generated vapors cascade to downstream effects running at progressively lower pressure and temperature.
- Concentration Control: Online density/conductivity governs recycle/discharge; clean condensate is recovered for reuse or polishing.
- Vacuum Crystallization (AS): Concentrate is cooled under vacuum to crystallize ammonium sulfate; crystals are separated by centrifuge and dried.
- Utilities & Emissions: Surface condenser with vacuum package; non-condensables safely vented; minimal cooling water through heat recovery.
Technical Snapshot (Illustrative)
| Item | Typical Range / Note |
| Evaporation capacity | 3–20 t/h per train (customized to plant load) |
| Steam economy | ~3.0–4.0 kg water/kg steam (higher with TVR/MVR add-ons) |
| Boiling temperature (last effect) | ~45–60 °C under vacuum to limit scaling & color set |
| Materials of construction | SS316L (product side), SS304 (non-product & structure); duplex/titanium optional for aggressive chemistries |
| Automation | PLC/HMI with historian; refractometer/density loops; surge & vacuum interlocks; remote diagnostics |
| Ammonium sulfate product | Crystal size tuned via residence time/seed loading; downstream centrifuge & dryer packages available |
| CIP strategy | Heated alkaline/acid cycles; recipe library based on pilot data and fouling index |
| Utilities | Reduced fresh steam and cooling demand through staged heat reuse; power sized to pumps & vacuum |
Key Benefits
- Lower OPEX: Multi-effect energy reuse with optional TVR/MVR modules.
- High Availability: Falling-film design with anti-fouling distribution; long runs between CIP.
- Compliance-Ready: Documentation for environmental audits, pressure-part codes, and safety.
- Revenue from AS: Turn sulfate burden into saleable ammonium sulfate crystals.
System Views
Scope & Deliverables
- Process design pack: PFD/P&ID, heat & mass balance, control narrative, utility list.
- Skid-mounted effects, separators, surface condenser, vacuum system, pumps & instrumentation.
- Integrated AS crystallizer, centrifuge and dryer (optional modules).
- Commissioning, performance testing to guaranteed KPIs, and operator training.
Applications
- Dye & dye-intermediate wastewater concentration with ammonium sulfate recovery.
- RO reject and high-TDS mixed effluents in chemical processing zones.
- Integration with biological/advanced oxidation for color & COD polishing.
About Hanpu
Hanpu delivers energy-saving MEE/MVR systems in stainless steel for challenging industrial effluents. Our EPC approach shortens schedules, stabilizes lifetime OPEX, and provides reliable compliance for chemical, dye, pharmaceutical, and mineral processing clients worldwide.