Filter Drier Function, Molecular Sieve Core & Sizing for Cold Room System
Filter drier is installed on liquid line; dual function: trap solid debris and adsorb water inside refrigeration circuit. Moisture in system will cause capillary/expansion valve ice block, hydrolysis of POE oil, acid formation and copper plating. Internal medium: molecular sieve + filter screen; molecular sieve adsorbs water, filter mesh intercepts metal chips, flux and oxide powder. Two common structure: solid core type (replaceable core) and disposable hermetic type for small unit. Xiteliduo standard rack system adopts replaceable core filter drier, convenient for long-term maintenance of export projects. Sizing rule: drier capacity matches system refrigerant charge; undersized drier saturates quickly and loses water adsorption capacity. After compressor burnout accident, oversized filter drier is required to remove acid and carbon residue continuously. Filter drier must be installed with arrow consistent with refrigerant flow direction; reverse installation blocks liquid flow. For low-GWP HFO system, water limit is stricter than R404A; drier selection margin should be increased appropriately. Refrigeration maintenance & repair company judges drier saturated when sight glass shows continuous moisture indicator yellow alarm.
FAQ
- Where is filter drier installed? Liquid line before expansion valve.
- What is the main hazard of residual moisture in system? Ice block, oil hydrolysis, acid corrosion and copper plating.
- What is the adsorbent inside drier? Molecular sieve.
- Can filter drier be installed against flow direction? No, follow arrow direction.
- What drier type for large refrigeration rack? Replaceable core filter drier.
- What color indicates moisture alarm in sight glass? Yellow.
- What upgrade for system after compressor burnout? Use oversized filter drier for acid cleaning.
- Why low-GWP HFO system needs bigger drier margin? More sensitive to moisture pollution.
