Introduction to Rising Film Evaporator

Rising film evaporator is an industrial evaporation equipment suitable for processing large quantities of heat-sensitive and foaming solutions. As a type of thin film evaporator, the rising film evaporator can provide efficient heat transfer and rapid evaporation process, which plays an important role in ensuring product quality and improving production efficiency.

Rising film evaporator composition

The system composition of the rising film evaporator mainly includes:

Shell: It serves as the main structure of the rising film evaporator and provides protection and support for the internal components.

Heating tube: This is the key part of the rising film evaporator, usually composed of one or more vertical long tubes with an aspect ratio of about 100-150 and a tube diameter between 25-50mm. The raw liquid is heated and boiled in the heating tube, generating secondary steam and rising along the tube wall in a film-like manner.

Separation chamber: Located at the top of the heating chamber, it is used to separate the concentrated liquid from the secondary steam to ensure the effective distinction between the concentrated liquid and the steam.

Preheater: The preheater is used to preheat the raw liquid to near the boiling point to ensure that it can quickly vaporize and form a film-like flow when entering the heating tube.

Film-making device (if applicable): In some designs, a film-making device may be required at the top of the heating tube to ensure that the solution can form a uniform film on the tube wall.

Condenser: In some designs, a condenser for condensing secondary steam may also be included to recover or treat the evaporated gas.

Rising film evaporator product advantages

The rising film evaporator system has the following characteristics:

High heat transfer efficiency: Since the raw material liquid forms a thin film on the inner wall of the heating tube, the contact area with the heating surface is increased, thereby improving the heat transfer coefficient and thermal efficiency.

Short residence time: The solution passes through the heating chamber in the form of a liquid film and does not circulate, so the residence time of the solution in the evaporator is short, which is particularly suitable for the evaporation of heat-sensitive materials.

Stable operation: The rising film evaporator can provide stable operating conditions, which helps to maintain an efficient evaporation process and reduce energy consumption.

Wide applicability: It is suitable for processing solutions with large evaporation volume, heat sensitivity and easy foaming, but it is not suitable for solutions with high viscosity, crystal precipitation or easy scaling.

Scope of application of rising film evaporator

The rising film evaporator system is mainly widely used in:

Chemical industry: The rising film evaporator is mainly used for solvent recovery and purification in the chemical industry. It can effectively separate organic solvents from solutions and realize solvent recovery and reuse, thereby reducing the cost of waste liquid treatment.

Food industry: In the field of food processing, rising film evaporators are often used to concentrate liquids such as juice, dairy products, alcohol, cooking oil and beverages. Through evaporation, water can be removed to achieve the purpose of concentration and purification, while retaining the nutrients of the raw materials.

Environmental protection industry: Rising film evaporators play an important role in treating wastewater and waste liquid. It can evaporate organic matter in wastewater, reduce the volume of waste liquid and pollution to the environment, and realize the resource utilization of waste liquid.

The principle of rising film evaporator technology is mainly based on the steam formed after the liquid is heated and boiled in the heating tube, which can drive the liquid to rise along the tube wall into a film shape, so as to realize the evaporation and concentration of the solution.

1. Preheating process: the raw material liquid is first preheated to reach a temperature close to the boiling point.

2. Evaporation process: the preheated raw material liquid is introduced into the tube from the bottom of the heating chamber. After being heated in the tube, the liquid quickly vaporizes to form secondary steam, and the secondary steam generated in this process will drive the liquid to flow upward along the tube wall in a thin film.

3. Separation process: As the solution evaporates upward along the tube wall, it is gradually concentrated and finally reaches the required concentration at the top of the heating chamber. Here, the concentrated liquid is separated from the secondary steam.

The process flow of the rising film evaporator mainly includes the following steps:

Preheating: First, the raw material liquid is heated by the preheater so that it reaches a temperature close to the boiling point.

Feed: the preheated raw material liquid enters the heating tube of the evaporator from the bottom.

Evaporation: In the heating tube, the raw material liquid is heated and boiled to generate secondary steam. In this process, the secondary steam drives the liquid to flow upward along the tube wall in a thin film

shape, forming the phenomenon of "rising film".

Concentration: As the solution evaporates upward along the tube wall, the liquid gradually concentrates. At the same time, the secondary steam is separated from the concentrate at the top.

Separation: The concentrated liquid and the secondary steam are separated in the separation chamber to ensure the effective separation of concentrated liquid and steam.

Discharge: the concentrated liquid is discharged from the bottom of the evaporator, while the secondary steam enters the condenser for condensation.

Post-treatment: Finally, the concentrated liquid and the secondary steam after condensation are treated as needed, such as solvent recovery or discharge.