Technical Introduction to Horizontal Tube Falling Film Evaporators

I. Structure and Working Principle

Core Component Design

The horizontal tube bundle falling film evaporator employs a horizontal tube bundle configuration. The feed solution is uniformly distributed across the heating tube surface via a top distributor, forming a continuous liquid film that flows downward. Its shell, tube bundle, and separation chamber are constructed from stainless steel or carbon steel, making it suitable for various corrosive media.

Evaporation and Heat Transfer Mechanisms

The liquid film flows along the horizontal tube wall under the combined effects of gravity and vacuum induction. A heating medium (such as steam) is introduced into the shell side for indirect heat exchange, enabling rapid evaporation. Secondary steam and concentrated solution undergo efficient separation in the separation chamber, with the steam being recovered for reuse or directed to the next effect of the evaporation process.

Dynamic Film-Forming Properties

By optimizing distributor structures (such as perforated discs or nozzles) and treating tube wall surfaces, uniform liquid film distribution and controllable film thickness are ensured, reducing the risk of localized dry wall scaling and enhancing heat transfer efficiency.

II. Process Advantages

High-efficiency heat transfer: With a thin liquid film and high flow velocity, it exhibits low thermal resistance and a significantly higher heat transfer coefficient than traditional vertical falling film evaporators.

Low energy consumption: Utilizes residual heat from secondary steam and a multi-effect cascade design to reduce steam consumption.

Broad Applicability: Suitable for continuous evaporation and concentration of heat-sensitive materials (such as food and pharmaceuticals) as well as high-viscosity, fouling-prone media (such as chemical waste liquids and black liquor from pulp processing).

III. Typical Application Scenarios

Chemical Industry: Used for concentrating low-concentration brine, caustic soda solutions, and other similar solutions, as well as in solvent recovery processes.

Food Processing: Low-temperature concentration of fruit juices and dairy products to preserve nutritional content and flavor.

Environmental Treatment: Minimizing the volume of landfill leachate and organic waste liquids to reduce subsequent disposal costs.

IV. Operational Precautions

Anti-scaling Measures: Regularly clean pipe walls, optimize the uniformity of material distribution, and prevent localized overheating that leads to scaling.

Temperature Control: Maintain an appropriate temperature difference between the heating medium and the material solution (typically ≤20°C) to prevent degradation of heat-sensitive components.

Equipment Maintenance: Monitor the operational status of the distributor and separation chamber to ensure efficient gas-liquid separation and steam quality.

Through the integration of horizontal tube bundle layout and dynamic film-forming technology, horizontal tube falling film evaporators demonstrate significant advantages in heat transfer efficiency, operational flexibility, and energy consumption control, establishing themselves as a key equipment option in industrial evaporation applications.