2–20 m²
Standard heat-transfer areas with larger sizes on request.
Falling Film Evaporators
Glass falling-film evaporators for short-contact-time concentration, distillation and solvent recovery of heat-sensitive or corrosive liquids.
UD Technologies · Vadodara, India
Short-residence evaporation
Concentrate sensitive liquids in a rapidly moving film.
Feed is distributed evenly across the inside of vertical heating tubes and flows downward as a thin film. Heat supplied through the surrounding shell partially evaporates the liquid; concentrate and vapour then enter a separator for independent withdrawal.
Low liquid hold-up, small temperature differences and contact times of only a few seconds per pass make falling-film evaporation well suited to heat-sensitive products. Reliable operation depends on complete tube wetting and a distribution system designed for the feed rate, viscosity and operating condition.
4–12 inch
Available evaporator diameters across pilot and production scales.
Seconds per pass
Short contact time protects heat-sensitive material.
Low hold-up
Fast startup and easier product or cleaning changeover.
Salient features
High heat transfer with low product exposure.
Distribution, wetting, vapour direction and automation are engineered together for stable concentration.
Even liquid distribution
A purpose-designed head wets the tube surface uniformly.
Rapid heat transfer
The thin film supports evaporation with a low temperature difference.
Responsive control
Feed, vacuum, energy input and concentration respond quickly to adjustment.
Visible processing
Glass makes film distribution, boiling and fouling directly observable.
Consistent concentrate
Automatic controls can stabilise product concentration.
Corrosion-resistant construction
Borosilicate glass and PTFE suit aggressive process liquids.
Flow arrangements
Select vapour flow and separation around the duty.
The relative direction of vapour and liquid changes film thickness, heat transfer, stripping and low-temperature performance.
Co-current falling-film evaporation
Liquid and vapour travel downward together
Vapour shear thins the liquid film and can improve heat transfer and stripping before bottom separation.
Process characteristics
- Flow direction
- Liquid and vapour downward in parallel
- Separation
- Concentrate and vapour separate at the bottom
- Film effect
- Vapour shear can thin the film
- Typical benefit
- Higher heat-transfer coefficient and effective stripping
Counter-current falling-film evaporation
Vapour rises against the descending liquid film
Counter-current operation can support vacuum evaporation at low temperature or the introduction of inert gas to lower partial pressure.
Process characteristics
- Liquid withdrawal
- Concentrate removed at the bottom
- Vapour withdrawal
- Vapour removed at the top
- Typical benefit
- Low-temperature vacuum or inert-gas-assisted operation
- Design caution
- Vapour rate must avoid flooding and unstable operation
Related system
Handle more viscous or fouling feeds with active wiping.
A wiped-film evaporator mechanically renews the product film where gravity flow alone is insufficient.
Discuss your requirements