Introduction to rising film evaporation equipment

Rising film evaporation equipment is an efficient industrial evaporation device designed to handle large quantities of heat-sensitive and easily foaming solutions. As an advanced form of thin film evaporation technology, rising film evaporation equipment provides efficient heat transfer and a rapid evaporation process, which plays a vital role in ensuring product quality and improving production efficiency.

Composition of rising film evaporation equipment

The core components of the rising film evaporation equipment include:

Shell: It constitutes the main body of the equipment and provides protection for the internal components.

Heating tube: This is the key part of the rising film evaporation equipment. It is 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 material liquid is heated and boiled in the heating tube, generating secondary steam and rising in a film-like manner along the tube wall.

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 material 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-laying device: In some designs, a film-laying device may be required on 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 further process the evaporated gas.

Advantages of rising film evaporation equipment

Rising film evaporation equipment has the following significant advantages:

Ultra-high heat transfer efficiency: The thin film formed on the inner wall of the heating tube greatly increases the heat exchange area, thereby improving the heat transfer coefficient and thermal efficiency.

Short residence time: Since the solution passes through the heating tube quickly in the form of a thin film and does not need to be circulated, the residence time in the evaporation system is shortened, which is especially suitable for heat-sensitive materials.

Stable operating performance: The rising film evaporation equipment can provide stable operating conditions, which helps to maintain an efficient evaporation process while reducing energy consumption.
Wide range of applications: It is especially suitable for processing large amounts of heat-sensitive or foaming solutions, but it is not suitable for solutions with high viscosity, easy crystallization or easy scaling.

Rising film evaporation equipment application scope

Rising film evaporation equipment is widely used in:

Chemical industry: mainly used for solvent recovery and purification, effectively separating organic solvents, realizing resource reuse, and reducing waste liquid treatment costs.

Food industry: commonly used for the concentration of juice, dairy products, alcohol, edible oil and beverages, removing water through evaporation to achieve the purpose of concentration and purification while retaining nutrients.

Environmental protection industry: plays an important role in the field of wastewater treatment, reducing the content of organic matter through evaporation, reducing the volume of waste liquid, reducing the environmental burden, and realizing resource utilization.

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.