High-Efficient Double-Effect Crystallization System for Multiple Salts
Hanpu designs and supplies double-effect evaporation & vacuum crystallization systems for multi-salt applications such as NaCl, KCl, (NH4)2SO4, Na2SO4, sodium acetate, and mixed brines. Our compact two-effect layout delivers strong energy savings, precise crystal size control, and reliable operation for both new plants and brownfield upgrades.
Technology Parameters
| Model |
DE-500 |
DE-1000 |
DE-1500 |
DE-2000 |
| Evaporation (kg/h) |
500 |
1000 |
1500 |
2000 |
| Steam Consumption (kg/h) |
≤250 |
≤500 |
≤750 |
≤1000 |
| Dimensions L×W×H (m) |
4×1.5×3.3 |
5×1.6×3.5 |
6×1.6×3.7 |
6.5×1.7×4.3 |
| Cycle Water Consumption (t/h) |
6 |
12 |
15 |
18 |
Operating Ranges (common to all models)
| Evaporation Temperature -- First Effect (°C) |
80-90 |
| Evaporation Temperature -- Second Effect (°C) |
55-70 |
| Vacuum -- First Effect (MPa) |
0.02-0.04 |
| Vacuum -- Second Effect (MPa) |
0.05-0.06 |
| Steam Pressure (MPa) |
<0.25 |
| Concentration Ratio |
1.2-1.3 |
System Features
Energy Efficiency
Typical steam economy of ~1.8-2.2 kg water/kg live steam (higher with TVR), cutting utility cost vs. single-effect systems.
Crystal Quality
Tight control of supersaturation, magma density, residence time, and seeding to hit target PSD and purity.
Low Fouling & Easy CIP
Optimized velocities and heat flux reduce scaling on heat surfaces; automated CIP quickly restores U-value.
Flexible to Multiple Salts
Process recipes switchable for chloride, sulfate, phosphate, and acetate systems; compatible with upstream RO/NF and downstream centrifuges/dryers.
How the Double-Effect Crystallization Works
- Preheat & Deaerate: Feed is preheated using condensate/flash vapors; non-condensables removed to stabilize boiling points.
- Effect 1 (Higher T/P): Falling-film or forced-circulation evaporation raises concentration near the metastable zone.
- Effect 2 (Lower T/P, Vacuum): Secondary vapor from Effect 1 heats Effect 2; controlled flash cooling and/or evaporative cooling develop supersaturation.
- Crystallizer: OSLO/FC or draft-tube-baffle configuration manages magma density and growth, limiting fines.
- Solid-Liquid Separation: Centrifuge or pressure filter recovers crystals; mother liquor is recycled or purged based on impurity build-up.
- CIP & Turnaround: Automated alkaline/acid cycles with conductivity endpoints; short downtime between campaigns.
Delivery Workflow
Feed analysis & targets → Thermal design & heat/mass balance → Pilot validation (as needed) → Detailed engineering → Fabrication & FAT → Installation & commissioning → Performance testing & training → Lifecycle service & spares.
Performance figures are indicative. Final design is confirmed by laboratory data, BPE/viscosity curves, corrosion/scaling assessment, and site utility conditions.
