Multi-Effect Falling Film Evaporator – Efficient Concentration for Milk Powder & Special Medical Purpose Foods

The multi-effect falling film evaporator is a high-efficiency evaporation equipment that utilizes the latent heat of steam through multiple reuses. Material enters the heating tubes from the top and, under the action of gravity and airflow, forms a liquid film flowing downward along the tube wall. Simultaneously, it is heated by steam outside the tubes, achieving rapid vaporization and separation of moisture, ultimately obtaining a highly concentrated liquid.

Application Positioning

This equipment focuses on the milk powder and special medical purpose food (special medical food) industries. It is core used for the concentration treatment of cow's milk, goat's milk, and special medical formula liquids, providing critical pre-process support for subsequent spray drying powder production.

Core Working Principle (Multi-Effect Falling Film + Heat Recovery Logic)

Taking the mainstream three-effect/four-effect falling film evaporation in the dairy industry as an example, combined with the multi-body series connection characteristics shown in the diagram, the principle is divided into two levels: "single-effect process" and "multi-effect linkage."

Single-Effect Internal Process:
Raw milk is delivered by the feed pump to the top of the first-effect evaporator. Through a distributor, it enters the heating tubes, forming a uniform liquid film flowing downward under gravity. Live steam is introduced outside the tubes, heating the liquid film inside the tubes via heat conduction, causing rapid vaporization of moisture in the feed liquid and generating "secondary steam." The vapor-liquid mixture enters the separation chamber. Through centrifugal/gravity separation, the concentrated liquid is collected downward, while the secondary steam is discharged upward.

Multi-Effect Linkage Heat Recovery:
The secondary steam generated in the first effect serves as the heating steam for the second effect, and the secondary steam from the second effect serves as the heating steam for the third effect, and so on.

Core Advantages

• Heat-Sensitive Protection – Preserves Nutritional Components
  The falling film evaporation design allows the feed liquid to remain in the heating tubes for only 3–10 seconds, operating under vacuum and low-temperature conditions. It maximizes the retention of heat-sensitive nutrients such as whey protein, lactoferrin, and vitamins, meeting the nutritional retention requirements of special medical purpose foods.

• High Energy Efficiency – Reduces Production Costs
  The multi-effect design achieves "cascade utilization" of steam. The steam consumption per ton of concentrated milk produced is significantly lower than that of single-effect evaporators, greatly reducing the energy cost of milk powder production.

• Sanitary Design – Compliant with Industry Regulations
  The main body is made of 304/316L food-grade stainless steel. Piping connections use quick-assembly structures with no sanitary dead spots. Supports CIP (Clean-In-Place) and SIP (Sterilization-In-Place), meeting GMP (Good Manufacturing Practice) sanitation requirements for milk powder and special medical purpose foods.

• Low Fouling Tendency – Reduced Maintenance Costs
  The feed liquid flows as a thin film, providing uniform contact with the heating tube wall and a short residence time, significantly reducing the probability of protein and lactose fouling. When used with food-grade anti-scalants, it extends the equipment cleaning cycle and reduces downtime maintenance costs.