Falling Film Evaporator — High-Efficiency Thin-Film Evaporation Concentration System

Product Overview

The Falling Film Evaporator is a concentration device in which the feed liquid forms a thin film on the inner walls of heated tubes and flows downward by gravity while evaporating. The secondary vapor generated can be reused in multi-effect evaporation systems, significantly improving thermal efficiency. It is ideal for heat-sensitive, low-viscosity, and non-fouling materials, widely used in chemical, food, pharmaceutical, and environmental industries.

Working Principle

Preheated feed enters the top of the evaporator and is evenly distributed into each heating tube by a liquid distributor, forming a continuous and stable falling film. The liquid film flows downward by gravity while absorbing heat from the heating medium outside the tubes, resulting in rapid evaporation. The generated secondary vapor is separated from the concentrated liquid in the separation chamber. The vapor can be directed to the next effect as a heat source for multi-effect energy savings.

Core Components

Liquid Distributor: Ensures uniform feed distribution to all tubes, preventing dry spots and fouling.

Heating Tube Bundle: Typically long vertical tubes; material flows inside, heating steam outside.

Separation Chamber: Uses tangential inlet or demisters to separate vapor from concentrate.

Circulation Pump: Optional for partial recirculation to adjust concentration and output.

Condenser: Condenses the final effect vapor to maintain vacuum.

Product Features

High Heat Transfer Efficiency: Thin, uniform liquid film provides high heat transfer coefficients and low temperature loss.

Short Residence Time: Material stays in the tubes for only seconds to tens of seconds, perfect for heat-sensitive products.

Low Pressure Drop: Gravity-driven flow reduces energy consumption.

Wide Operating Range: Stable operation at 30%–120% load with proper distributor design.

Compact Design: Vertical configuration saves floor space and allows multi-effect or MVR integration.

Typical Technical Specifications

Parameter	Specification Range / Description
Processing Capacity	1.0–60 t/h (customizable)
Evaporation Temperature	50–90 °C (vacuum adjustable)
Heat Transfer Coefficient	1200–3000 W/(m²·K)
Evaporation Ratio per Effect	Approx. 0.3–0.5 ton steam/ton water
Material of Construction	SS304/316L, Duplex Stainless Steel, Titanium, etc.
Control Mode	Manual / PLC automatic control
Suitable Viscosity	≤ 500 cP (higher with special design)

Application Fields

Industry	Typical Applications
Food & Beverage	Milk, fruit juice, syrup, plant extract low-temp concentration
Pharmaceutical	TCM extract, antibiotic solution, vitamin concentration
Chemical	Dilute caustic soda, urea, dye intermediate concentration
Environmental Protection	Low-salinity wastewater concentration, landfill leachate pretreatment
Bio-fermentation	Fermentation broth concentration, enzyme recovery