Activated alumina balls play a crucial role in air compressors, primarily functioning as a desiccant for gas absorption, dehumidification, and drying. This article will introduce their usage in air compressors from multiple aspects.
Product Features of Activated Alumina Balls
Activated alumina balls characterized by their high porosity, with a white spherical appearance. They have a smooth surface, no dust or broken particles, and a pure white color. The balls have a rigid framework structure formed by hydroxide crystals, making them highly stable. They won’t soften, swell, or crack when immersed in water, and are wear – resistant and shock – resistant.
Working Principle in Air Compressors
In air compressors, the main purpose of using activated alumina ball is to adsorb and purify the moisture in the compressed gas. The high specific surface area of activated alumina ball provides numerous adsorption sites. When the compressed gas passes through the layer of activated alumina balls, water molecules adsorbed onto the surface of the balls through physical adsorption, thereby reducing the moisture content in the gas and achieving the goal of drying.
Technical Requirements
Appearance
The particles of activated alumina ball should be complete, with a smooth spherical shape. There should be no broken particles or dust, and the color should be pure white without any variegated balls.
Specific Surface Area of Activated Alumina Balls
As a desiccant, the specific surface area of activated alumina required to be at least 300 m²/g. This large specific surface area ensures sufficient contact between the balls and the gas, facilitating efficient moisture adsorption.
Static Water Adsorption Value of Activated Alumina Balls
The static water adsorption value generally needs to reach above 16.8%. Currently, high – quality activated alumina can achieve a static water adsorption value of about 17%, which means it can adsorb a relatively large amount of water.
Water Absorption Rate
The water absorption rate is an important indicator of the adsorption performance of the desiccant. The water absorption rate of activated alumina required to reach 49%, and in practice, it can reach up to 50%. This high water absorption rate ensures the drying effect of the compressed gas.
Strength
Since the air pressure in the gas dryer is relatively high, activated alumina balls need to have sufficient strength. For example, the strength of commonly used 3 – 5mm activated alumina balls should be ≥150N/particle, 4 – 6mm balls ≥160N/particle, 5 – 7mm balls ≥180N/particle, and 6 – 8mm balls ≥200N/particle.
Usage and Precautions of Activated Alumina Balls
Usage
Activated alumina balls used in various types of air – drying equipment in air compressors, such as air – compression dryers, adsorption dryers, micro – heat dryers, heat – type dryers, and non – heat dryers.
Precautions
- Before use, do not open the packaging bag to prevent the balls from absorbing moisture in the air, which could affect their drying performance.
- This product is suitable for deep drying, and it recommended to use it under a pressure greater than 5 kg/cm².
- After a certain period of use, the adsorption performance of the activated alumina balls will gradually decline. At this time, they need to regenerate. Regeneration can achieve by maintaining them in air or an inert gas at a temperature of 120 – 240°C for 3 hours to remove the adsorbed moisture, enabling repeated use.
Packaging and Storage
- Activated alumina ball usually pack in polypropylene woven bags lined with a layer of ethylene film, with a net weight of 25 kg per bag. Special packaging can customize according to customer requirements.
- They should store in a dry place, protected from water and moisture. Contact with water or water vapor strictly avoided.
In conclusion, activated alumina ball is an essential and effective desiccant in air compressors, which can ensure the dryness of compressed gas and improve the efficiency and service life of air – compression systems.
