The functional principle and selection of filter drier in HVAC system
Filter drriers play an important role in filtration and drying in the refrigeration system, ensuring the purity and stability of the refrigerant, thereby improving the efficiency and life of the system. Prevents ice and dirt clogging of the refrigeration system, thereby protecting components such as throttle valves and compressors. Because filter driers accumulate impurities over time and use, regular replacement and maintenance are necessary measures to keep your refrigeration system running efficiently. Its functional principle and selection are as follows:
Functional principle: Removal of moisture: The filter drier is mainly used to remove moisture in the air and prevent water vapor from entering the gas system, causing equipment corrosion and failure.
Removal of solid particles: The filter can effectively filter solid particles in the air, such as dust, soil, etc., to protect the normal operation of pneumatic equipment.
Reduced oil stains: Filter driers can also partially remove oil stains from some compressors, maintaining the cleanliness of the system.
Structural Part: Housing: Filter driers are usually made of metal housings that protect the internal filter material and connect to the pipes of the refrigeration system.
Filter material: The filter drier is filled with adsorbents, usually activated aluminate or silica gel, which are able to absorb moisture and impurities in the refrigerant.
End caps: Filter-drier usually has metal or plastic end caps at both ends to secure the filter material and connect with the pipes of the refrigeration system through the connection port.
Inlet and outlet connections: There are usually two connections on the filter drier, one for the inlet of the refrigerant and the other for the outlet of the refrigerant.
Precautions for selection:
Gas flow: According to the gas flow rate of the air compression system, select the appropriate filter drier model to ensure that its processing capacity can meet the system requirements.
Working Pressure: Ensure that the rated working pressure range of the filter drier matches the working pressure of the air compression system to avoid damage or failure of the equipment.
Refrigerant type: Different types of refrigerants differ in chemical properties and conditions of use. Make sure that the filter drier you choose matches the refrigerant used in your refrigeration system to ensure efficient filtration and drying.
Filtration level: According to the air quality requirements, select the appropriate filtration level, usually in microns (m) to express the filtration precision.
Humidity treatment: For different application scenarios, the adsorbent type can be selected as a filter drier or a condensing type filter drier, the former is suitable for the environment with high relative humidity, and the latter is suitable for the lower humidity conditions.
Maintenance requirements: Consider the maintenance cycle and replacement frequency of the filter, and select the model suitable for operation and maintenance.
The right filter drier selection helps to ensure reliable operation of the air compression system and consistent gas quality.
It may cause impurities to enter the system:
Damage or aging: Filter driers can crack or age due to prolonged use or external damage, causing impurities to enter the system.
During the operation of the refrigeration system: when the refrigerant contains water, it will be hydrolyzed into acidic substances, which will corrode the metal. The mixture of refrigerant and lubricant can dissolve copper and carry it to the compressor to form a copper film on the metal surface of the compressor, which can affect the operation of the compressor, and moisture can also cause system ice blockage.
Incorrect installation: If the filter drier is not properly installed or poorly sealed, it can cause the refrigerant to bypass the filter and enter the system.
Wrong Choice: Selecting a filter drier that is not suitable for the refrigeration system or type of refrigerant may not effectively remove impurities, allowing them to enter the system.
Improper maintenance: Filter driers need to be replaced and maintained regularly, and if the filter is not replaced according to the specified cycle, it may lead to a decrease in its effectiveness and inability to effectively remove impurities.