Filter Dryer: Introduction, Importance, and Function

1. What is a Filter Dryer?
A filter dryer is a crucial component in refrigeration and air conditioning systems, typically installed in devices such as chillers, air conditioners, and refrigerators. Its primary role is to prevent the ingress of impurities and moisture into the refrigeration cycle.
2. The Necessity of Using a Filter Dryer
Given that there is a possibility of moisture and impurities entering the system during the design and implementation phases, a filter dryer serves as a preventive element. In smaller devices like ducted split systems, which are usually sealed carefully at the factory, the likelihood of these impurities is much lower, hence these devices typically do not include filter dryers.
3. Types of Impurities That May Enter the Refrigeration Cycle
Some common impurities that may enter the refrigeration cycle of chillers include:
• Dust
• Metal shavings
• Sediment
• Moisture
• Solder flux
• Acids generated by refrigerant moisture
4. Dangers of Moisture in the Refrigeration Cycle
Moisture presence in the refrigeration cycle poses significant dangers:
• Chemical Reactions: Moisture can react with chemical components of compressor oil or refrigerant, leading to the production of strong and weak acids that can corrode compressor parts over time.
• Refrigerant Decomposition: If the refrigerant contains halogen elements, the introduction of moisture can lead to its decomposition, resulting in the formation of inorganic acids.
• Oil Disturbance: In compressors using organic oil, contact with moisture and oxygen at elevated temperatures can lead to the breakdown of the oil structure, producing organic acids.
5. Components of a Filter Dryer
A filter dryer is comprised of various components that aid in filtration:
• Desiccant Materials: Such as felt that can fully absorb moisture.
• Mesh Screens: These screens serve to prevent the exit of particles and contaminants from the system.
6. Conclusion
As a key element in refrigeration and air conditioning systems, the filter dryer helps improve efficiency and extend the lifespan of devices by preventing the entry of impurities and moisture into the refrigeration cycle. Therefore, proper selection and maintenance of these filters are essential for optimizing the performance of air conditioning and chiller systems.