Welded Single Effect Vacuum Evaporator — Forced Circulation For Wastewater
Welded single-effect vacuum evaporator with forced circulation engineered for industrial wastewater reduction, brine concentration, and ZLD pre-concentration. Operating under vacuum lowers boiling temperature, while high-velocity circulation improves heat transfer and mitigates scaling—delivering stable throughput, robust operability, and straightforward maintenance.
Key Benefits
- Reliable with difficult feeds: Forced circulation tolerates suspended solids and high salinity.
- Lower-temperature duty: Vacuum operation protects heat-sensitive streams and reduces fouling risk.
- Simple & maintainable: Welded construction, clean flow paths, and wide operating window.
- Upgrade-ready: Optional TVR/heat-recovery to boost steam economy; easy integration into ZLD trains.
- Consistent condensate: Polishing options support reuse or compliant discharge.
Process & Thermal Economy
Live steam heats the circulating liquor in the main heater; vapor generated in the separator is condensed under vacuum. High circulation rates stabilize ΔT/LMTD, limit deposition on tubes, and keep capacity steady across varying wastewater chemistries. Optional TVR (thermo-vapor recompression) can improve thermal efficiency.
Controls & Safety
PLC/HMI with closed-loop control of level, pressure, ΔT, and conductivity; interlocks for vacuum/NCG handling, pumps, heaters, and condensate quality guard. Alarm/event historian and remote diagnostics available.
Materials & Maintainability
Wetted parts in SS316L/duplex (Ti/Hastelloy optional). Large clean-outs, removable heads, CIP provision, and anti-scale dosing support long campaigns and fast turnarounds.
Process Overview — Wastewater Concentration
- Feed conditioning: screening/filtration, softening or pH trim to reduce scaling/corrosion.
- Evaporation under vacuum: heater + separator with high-velocity loop for stable heat transfer.
- Condensate management: polishing (filters/RO/AC) to meet reuse/discharge limits.
- Concentrate routing: to crystallizer/centrifuge/dryer or upstream recycle per ZLD flowsheet.
- Automation: start/stop recipes, load following, and CIP sequences.
Key Components
- Evaporator body (welded) with forced-circulation pump and vapor–liquid separator
- Main heater, preheater, condenser, vacuum/NCG handling skid
- Instrumentation (T/P/flow/cond/level) with PLC/HMI/SCADA
- CIP skid and anti-scale dosing system
- Optional: TVR ejector, heat-recovery exchangers, condensate polishing filters/RO
Performance & Sizing
| Parameter | Typical Range* |
| Operation | Continuous |
| Shell pressure (vacuum) | ~8–25 kPa(abs), duty-dependent |
| Steam economy | ~1.0 (SE); up to ~1.5–2.2 with TVR/heat recovery |
| Circulation velocity | High to limit scaling and stabilize ΔT |
| Condensate quality | Polished for reuse or compliant discharge |
| Materials | SS316L / duplex; Ti/Hastelloy on request |
*Actual performance depends on feed chemistry, fouling tendency, and heat-exchange design.
FAQ
Why choose forced circulation over falling film?
It handles higher solids and variable wastewater better, keeping tubes clean with shear and stable heat transfer.
Can steam consumption be reduced further?
Yes. Adding TVR and heat-recovery exchangers raises steam economy; MVR can be integrated in hybrid upgrades.
Is it suitable for ZLD?
Absolutely—use as a concentrator ahead of crystallization/solid handling to minimize liquid discharge.
Application
