Wiped Film Evaporator
Evaporation
1. Product Overview
Wiped film evaporators are vertical cylindrical units with an internal rotor fitted with wiper blades that spread the feed into a thin film on the heated inner wall for rapid evaporation. Suitable for concentrating and separating high-viscosity, heat-sensitive, fouling-prone, and solid-laden materials.
2. Working Principle
Feed enters at the top; the rotating rotor presses wiper blades against the heated wall, evenly distributing the material into a thin film. The film moves downward in a spiral under gravity and wiper action while being heated and evaporated. Light components vaporize and rise to a condenser; heavy components are continuously discharged from the bottom.
3. System Classification
By wiper type:
Swing wipers: Good adaptability for general-viscosity materials
Roller wipers: Reduced friction for high-viscosity or particulate-laden feeds
Hinged wipers: Flexible contact for coking-prone materials
Fixed wipers: Simple structure for low-viscosity, clean materials
Elastic wipers: Constant contact pressure for high-viscosity and scaling-prone feeds
4. Detailed Technical Parameters
4.1 Common Materials
Table
| Material | Application | Remarks |
|---|---|---|
| SS 304 / 316L | Shell, rotor, wipers | General food, pharma, chemical |
| Hastelloy C-276 | Highly corrosive product-contact | Strong acids, oxidizing media |
| Titanium | Chloride-containing media | Pitting and crevice corrosion resistant |
| PTFE / PBI composite | Wiper liner | Corrosion resistant, low friction |
4.2 Typical Specifications (subject to design)
Table
| Heat transfer area (m²) | 0.8 | 1.5 | 2.5 | 4 | 6 | 10 |
| Steam pressure (MPa) | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 |
| Vacuum (kPa) | 70 | 70 | 70 | 70 | 70 | 70 |
| Evaporation rate (kg/h) | 160 | 300 | 500 | 800 | 1200 | 2000 |
| Motor power (kW) | 1.1 | 1.5 | 2.2 | 4 | 5.5 | 11 |
| Rotational speed (rpm) | 300 | 300 | 280 | 134 | 134 | 88 |
| Equipment height (mm) | 2500 | 3295 | 4100 | 5180 | 5800 | 7800 |
4.3 Design Conditions & Performance
Table
| Parameter | Specification |
|---|---|
| Evaporation intensity | up to 200 kg/m²·h |
| Residence time | 5 ~ 10 seconds |
| Viscosity range | 1 ~ 100,000 cP |
| Operating temperature | Ambient ~ 350 °C |
| Operating pressure | up to 2 bar; vacuum down to 0.001 mbar (short-path/molecular distillation configurations) |
5. Electrical Parameters
(Same as MVR evaporator table)
6. Key Component Selection
Table
| Component | Common Brand / Material | Features |
|---|---|---|
| Main shell (with jacket) | SS 304 / 316L / Hastelloy | Vertical cylinder, precision-bored and polished interior |
| Rotor assembly | Custom-fabricated | Includes shaft, frame, wipers; dynamically balanced |
| Shaft mechanical seal | National standard / imported | Single or double mechanical seal |
| Drive unit | VFD motor + gearbox | Adjustable speed for varying viscosity |
| Condenser | External or internal | Internal condenser for short-path designs |
7. Typical Applications
Pharmaceutical: API purification, solvent recovery, heat-sensitive drug concentration
Food: Fish oil, essential oils, natural extract concentration
Chemical: Polymer devolatilization, high-boiling solvent recovery, tar processing
Oils & fats: Fatty acid distillation, glycerin concentration
8. Design Standards & Certifications
Table
| Standard | Description |
|---|---|
| ASME Section VIII Div.1 | Pressure vessel design and fabrication |
| PED 2014/68/EU | EU Pressure Equipment Directive |
| ATEX | Explosion protection directive (if applicable) |
| GMP / FDA / cGMP | Pharmaceutical and food-grade requirements |
| ASME BPE | Bioprocessing equipment standard |
| ISO 9001:2015 | Quality management system |
9. Optional Custom Configurations
Table
| Option | Details |
|---|---|
| Wiper type | Swing / Roller / Hinged / Fixed / Elastic |
| Material upgrade | Hastelloy, titanium, glass-lined |
| Surface finish | Mirror polish Ra ≤ 0.4 μm |
| CIP/SIP | Clean-in-place / steam-in-place |
| Short-path distillation coupling | With internal condenser for molecular distillation |
10. Warranty Terms
(Same as MVR evaporator)
11. Packaging and Delivery
Table
| Item | Packaging |
|---|---|
| Evaporator body | Tarpaulin wrap, wooden skid, naked or crated |
| Rotor / wiper assembly | Fully enclosed wooden crate, rust-proof packing |
| Electrical / instruments | Waterproof sealed packaging in wooden cases |
| Container estimate | Heat transfer area ≤10 m²: approx. 1×20'GP; larger by 40' or break bulk |
12. Information Required for Inquiry
12. Information Required for QuotationMaterial name and chemical properties, throughput (kg/h), feed viscosity (cP), heat-sensitive temperature limit, solid content, target separation purity, available heating medium (steam/thermal oil), vacuum requirement, power supply, delivery terms, destination port.