Wheat Straw Pulp Evaporation Station with Five-Effect Pillow Plate Evaporator
Hanpu supplies a high-efficiency five-effect evaporation station engineered for wheat straw pulp mills. Using pillow plate (dimple plate) heat-exchange technology and falling-film hydraulics, the system concentrates black liquor or filtrates with low fouling, stable operation, and best-in-class steam economy—ready for chemical recovery or downstream crystallization.
Energy Saving
Five effects in series reuse vapor enthalpy, delivering a steam economy typically 4.0–5.5 kg water/kg steam, cutting boiler load and CO₂ emissions.
Low Fouling on Fibrous Streams
Pillow plate channels promote turbulence with wide cross-sections, reducing scaling and fiber deposition commonly seen with straw-derived liquors.
Compact & Maintainable
Lightweight plates allow tight footprints, easy access for inspection, and rapid plate replacement compared with bulky shell-and-tube bundles.
Recovery-Ready
Clean condensate reuse, optional strip-ping of volatiles, and NCG handling help meet environmental limits and improve alkali recovery performance.
Process Description
- Feed preheat: Inlet liquor is preheated by condensate/flash vapor to minimize live steam.
- Five-effect falling film: Even distribution over pillow plate panels; each downstream effect operates at lower pressure/temperature to cascade heat.
- Vapor–liquid separation: High-efficiency demisters avoid entrainment; clean condensate is recovered.
- Vacuum & NCG management: Surface condenser with vacuum pump removes non-condensables and controls TRS/odor.
- Automation: PLC/HMI with recipes, trend logs, and surge protection; inline density/solids for set-point control.
- Cleaning: Online water wash, alkaline/acid CIP, and optional piggable lines mitigate organic/inorganic fouling.
Materials & Compliance
- Metals: SS304/SS316L standard; Duplex 2205/2507 for chloride/alkali resistance in black liquor service.
- Gaskets & seals: EPDM/FKM/PTFE per temperature and chemical exposure.
- Standards: ASME/PED vessels, CE marking available; safety interlocks and pressure protection included.
Technical Snapshot
| Item | Typical Range / Note |
| Application | Wheat straw pulp liquor, filtrates, and side streams prior to recovery or crystallization |
| Evaporation capacity | 10–120 t/h per line (customizable by effect area and plate count) |
| Effects | Five-effect (optional TVR on selected effects to boost economy) |
| Steam economy | ~4.0–5.5 kg water/kg live steam (feed and ΔT dependent) |
| Operating temperatures | First effect ~95–105 °C → last effect ~55–65 °C (under vacuum; BPE considered) |
| Product outlet solids | Tailored to recovery boiler or crystallizer target; typical 45–65% TS |
| Controls | PLC/HMI, flow/level/pressure/temperature, density/°Brix (where relevant), condensate conductivity |
| CIP | Automated alkaline/acid/hot water cycles; online wash between batches or on condition |
| Footprint | Compact modular skids with accessible plate packs and separators |
Options & Enhancements
- Condensate stripping column for VOC/TRS reduction and water reuse.
- NCG collection with safe routing to oxidizer or recovery boiler.
- Heat-integrated preheaters and flash tanks to maximize internal energy recovery.
- MVR or additional TVR stages for higher electrical/steam flexibility.
Manufacturing & Assembly
Delivery Workflow
Feed data & targets → Thermal design & heat/mass balance → Pilot validation (optional) → Detailed engineering → Fabrication & FAT → Installation & commissioning → Performance test & training → Lifecycle service & spares.
Values shown are typical. Final design depends on liquor composition, BPE, viscosity curve, scaling tendency, and site utilities.