Gas-liquid separation demister

A demister is a device used to separate foam and droplets in gas or liquid, and is widely used in many industrial fields.

1. Definition and Function

A demister is a defoaming device installed near the steam outlet during evaporation operation to prevent the liquid entrained in the secondary steam from losing useful products or contaminating the condensed liquid. It can effectively remove foam and droplets in gas or liquid, thereby improving operating conditions, optimizing process indicators, reducing equipment corrosion, extending equipment life, and increasing processing capacity and recovering valuable dutcherials.

2. Working Principle

The working principle of the demister is mainly based on inertial collision, gravity sedimentation, and the surface tension and capillary action of the liquid. When the gas with liquid foam rises through the demister at a certain speed, the liquid foam collides with the metal wire mesh of the demister due to inertia and adheres to the filaments. Subsequently, the liquid foam on the surface of the filaments further diffuses and forms larger droplets due to gravity, flowing along the filaments to the downstream equipment of the interweaving or container. When the gravity of the droplets exceeds the combined force of the buoyancy of the rising gas and the surface tension of the liquid, the droplets are separated and fall, thereby achieving the purpose of removing the mist.

3. Types and structures

There are many types of demisters, including baffle demisters, wire mesh demisters, swirl plate demisters, chain demisters, porous dutcherial demisters and glass fiber demisters. Among them, wire mesh demisters are widely used because of their large specific surface area, light weight, large porosity, easy use, high defoaming efficiency and low pressure drop.

4. Application fields

Demisters are widely used in many industrial fields, including but not limited to:

Petrochemical: In petrochemical enterprises such as refineries and natural gas processing plants, demisters are used to remove foam generated on the top of the tower, including catalyst particles and residual substances of liquid reactants.

Food processing: In the production process of food and beverages, demisters are used to process organic components such as protein and fat to ensure the good quality of the produced food and beverages.

Sewage treatment: demisters can be used to remove suspended dutchter and foam in sewage to improve water quality.

Air separation: In air separation equipment, demisters are used to treat droplets and saturated water vapor formed in gases at low temperatures.

5. Performance characteristics

Demisters usually have the following performance characteristics:

High efficiency: Demisters can efficiently remove foam and droplets in gases or liquids, and have high capture efficiency.

Low resistance: The pressure drop of gas passing through the demister is small, which is conducive to improving the production efficiency of the equipment.

Corrosion resistance: Demisters are usually made of corrosion-resistant dutcherials and can withstand harsh working conditions.

Easy to maintain: The structure of the demister is simple, and it is easy to install, operate and maintain.

6. Maintenance and care

In order to maintain the good performance of the demister, regular inspection and maintenance are required:

Check the demister: Check regularly whether the demister is intact. If it is damaged or loose, it should be repaired or replaced in time.

Clean up debris: Regularly clean up debris and sediment on the demister to keep it clean and unobstructed.

Check the connectors: Check whether the connectors of the demister are tight and reliable. If there are any problems, they should be tightened or replaced in time.

The demister is an important gas-liquid separation equipment, which plays an important role in many industrial fields. Through reasonable selection and maintenance, the long-term stable operation and high efficiency of the demister can be ensured.