Introduction to Walk-In Freezers : Compressor

 1. Definition and Function:

• The compressor circulates refrigerant throughout the system, acting like a pump.
• It compresses low-pressure refrigerant vapor into high-pressure vapor, increasing its heat content.
• Often referred to as the heart of the refrigeration system.

2. Types of Compressors:

• Scroll Compressors:

  • Use two precisely matched scrolls to compress gas.
  • Serve larger capacity walk-in freezers.
  • Efficient, quiet, fewer moving parts, and hermetic (fully enclosed).
  • Higher initial cost; if one piece fails, the entire compressor needs replacement.
  • Easy maintenance: change air intake filters, clean condenser coil, maintain proper refrigerant charge.

• Reciprocating Compressors:

  • Most common and has the longest history.
  • Cheaper initial cost but smaller capacity and less efficient.
  • Positive displacement compressor using a piston driven by a crankshaft.
  • Regular maintenance needed to check for mechanical deterioration.

• Screw Compressors (Rotary Screw Compressors):

  • More efficient than reciprocating compressors but less common in walk-in freezers.
  • Lower operating costs and largest capacity.
  • Uses two meshing screws (male and female rotors) to compress gas.
  • Cooling and lubrication are critical due to close tolerances of mating rotors.

3. Troubleshooting and Maintenance:

• Signs of malfunction include short cycling on the overload protector, failure to reduce suction pressure, improper lubrication, flooding, slugging, flooded starts, and overheating.
• Mechanical failures in the system, like condenser coil buildup, can affect compressor performance.
• Regular maintenance should ensure proper lubrication, clean condenser coils, and proper refrigerant charge.

4. Importance:

• Compressors ensure refrigerant flow through the refrigeration system.
• A malfunctioning compressor stops the cooling process, resulting in no refrigeration effect.