A falling film evaporator is a device that utilizes thermal separation techniques to extract water or other solvents from a liquid. The method of falling film evaporation is the main reason for its widespread use in the food, chemical, and pharmaceutical industries. The product is primarily requested due to its one-of-a-kind energy-saving abilities, its flexibility while dealing with delicate products, and its reliable continuous operation. This guide explains its working, features, benefits, applications, and maintenance step by step.

What is a falling film evaporator?

A falling film evaporator is essentially an arrangement of several tubes, which is a vertical heat exchanger. The liquid is fed from the top and goes down the tubes as a thin film. Gravity continues to bring the liquid down while the steam or hot fluid that is outside the tubes heats it. The solvent vapor goes off while at the same time the concentrated product leaves the bottom.

Key Features of a Falling Film Evaporator

• Thin liquid film: The feed is transformed into a smooth layer along the tube walls.

• Gentle heating: Low temperatures cause less product damage.

• Fast evaporation: The high heat transfer rate makes the production faster.

• Continuous operation: The process can be run without much interruption.

• Compact design: The vertical setup saves space and makes handling easy.

How Does a Falling Film Evaporator Work?

The step-by-step working includes:

• Feed distribution: The liquid is fed from the top and spread evenly.

• Film formation: Gravity fills the liquid as a thin film.

• Heating process: Steam or a heating medium makes the tube surface warm.

• Evaporation: The solvent vapor separates from the liquid film.

• Separation: Vapors exit at the top while the concentrate leaves at the bottom.

Advantages of Falling Film Evaporators

• Energy efficiency: High heat transfer rates result in lower energy consumption.

• Product safety: The gentle heating method ensures the preservation of texture, taste, and quality of the product.

• Productive flexibility: The evaporator is applicable for liquids of any kind of viscosity.

• Cleaning friendly: The smooth surface of the tubes allows for fast washing.

• Modular design: It is equally suitable for both large and small industries.

Falling Film Evaporator vs Rising Film Evaporators

Both these evaporators are aimed at providing the same output, but they function in different ways.

Differences

• Movement of liquid: The film in the falling film evaporator moves down due to gravity, and in the rising film evaporator, a vapor lift helps the film to go up.

If we consider the temperature as the main factor, then it can be said that film systems in which the liquid falls are capable of handling heat-sensitive liquids, while those where the film is rising are suitable for stable products.

• Effort for maintenance: Maintenance of units with a falling film is easier, and the process also requires less time.

Reasons to Opt for Falling Film Evaporators

• Firstly, the product is gentle, such as juice, milk, or medicine.
• More evaporation with a lesser energy requirement is done.
• Continuous production is more efficient.

How to Use a Falling Film Evaporator?

Step 1: Feed Preparation

The liquid must be cleaned to remove big particles. A smooth feed will ensure that the film distribution is even.

Step 2: Proper Distribution

Dry patches are not formed if even spreading is done on the top. Besides, a balanced distribution also lessens the scaling inside tubes.

Step 3: Heating Control

The steam pressure has to be just right so that the operator can regulate it. Stable heating will avert overheating and energy dissipation.

Step 4: Vapor Separation

This machine does the separation of vapor from the liquid rapidly. Due to this, the product quality gets better, and there is no possibility of vapor recontamination.

Step 5: Product Collection

The concentrated liquid should be kept in sealed vessels. This keeps the product away from contaminants and prolongs its shelf life.

Falling Film Evaporators Applications

Falling film evaporators have been very successful in serving the different sectors that make up the world economy.

Food Industry

• Concentration of fruit juices
• Production of whey and milk concentrates.
• Keeping the flavors, aromatic components, and nutritional components intact.

Chemical Industry

• The purpose may be to recover and reuse solvents.
• Concentrating of caustic soda, acids, and brines.
• The treatment of industrial effluents.

Pharmaceutical Industry

• The concentration of herbal extracts.
• The safe processing of active ingredients.
• The achievement of high standards of purity and potency.

Other Industries

• For the recovery of water from desalination plants.
• Concentration of biofuel production solutions.
• The use of plant-based extracts by the cosmetic industry.

Maintenance and the Care of the Falling Film Evaporator

• Daily Cleaning: Operators must wash the tubes often. Frequent cleaning will avoid scaling and fouling.
• Checking the Seals: Seals and joints require regular inspection. Leak-free seals will prevent accidents and maintain safety.
• Performance Monitoring: Operators have to monitor the temperature and the flow rate every day. A proper control system acts as a guarantee for stable operation and fewer breakdowns.
• Preventive Maintenance: The scheduled maintenance prolongs the machine’s life. Checking regularly prevents costly shutdowns.

Advantages of Falling Film Evaporation

• It does not harm the delicate and heat-sensitive products.
• On-demand and continuous operation is possible.
• The effective heat transfer saves energy.
• The easy cleaning design reduces the maintenance required.
• The flexible applications allow for various industries to be supported.

Conclusion

The falling film evaporator is among the most efficient systems to carry out evaporation. It features energy efficiency, gentle heating, and a wide range of applications in different sectors. In comparison with the ascending film evaporators, it gives a higher output of the product, which is heat-sensitive. By using the falling film evaporators, industries can get high-grade products, lower their running costs, and have eco-friendly processes.

Why Alaqua?

If you are looking for dependable evaporation and processing equipment, Alaqua would be the right partner for you. Alaqua offers state-of-the-art falling film evaporators, rising film evaporators, and total processing systems. Our knowledge and support guarantee that your company will gain from the long-lasting performance and value. Get in touch with us now to find out how our answers can facilitate your manufacturing target.