Technical Support – Refrigeration Systems and Ice Machines

1. System Overview & Refrigeration Cycle

In flake ice machine manufacturing, understanding the refrigeration cycle is essential for efficient design and maintenance. The system operates on the vapor compression cycle, consisting of four primary components: compressor, condenser, expansion valve, and evaporator. The refrigerant flows continuously through these components, absorbing heat in the evaporator and rejecting it in the condenser.

Flake ice machines are specifically designed to operate at low evaporating temperatures to ensure rapid ice formation. An efficient cycle allows the ice machine supplier to provide consistent ice production even under high ambient conditions.

2. Refrigerants and Their Characteristics (R404A, R134a)

In industrial ice machine manufacturing, refrigerant selection is critical. TAMUTOM uses primarily R404A and R134a, both reliable and globally available gases.

• R404A: A blended refrigerant used in systems operating at -20°C to -40°C. It provides strong cooling performance but requires precise charge levels.
• R134a: Ideal for medium-temperature systems, with lower environmental impact (ODP=0) and stable pressure balance.

Proper superheat (5–10 K) ensures vapor-only return to the compressor, preventing liquid slugging. Excessive subcooling may cause overfeeding in the expansion valve and irregular ice formation inside the evaporator.

3. Expansion Valve Operation & Adjustment Procedures

The expansion valve (TXV) regulates refrigerant flow into the evaporator. During flake ice machine operation, it ensures optimal feed for stable evaporation and consistent ice quality.

1. Measure suction line temperature and pressure near the evaporator outlet.
2. Calculate superheat and compare it to the recommended value (6–8 K).
3. Adjust the valve stem gradually; one full turn can significantly affect balance.
4. Observe compressor load and ice thickness for stability.

Incorrect TXV setup can cause frost on the compressor or weak ice production. Calibration should be verified before shipment.

4. Liquid Line, Oil Return & Compressor Frost Causes

The liquid line carries condensed refrigerant to the expansion valve and should include a filter-drier, sight glass, and moisture indicator. Long liquid lines increase flash gas risk and unstable feed.

Common frost causes:

• Inadequate superheat causing liquid return
• Poor insulation or high humidity
• Insufficient defrost cycles

Solutions:

• Implement timed defrost cycles in humid environments.
• Ensure proper airflow around the condenser.
• Maintain suction velocity above 8 m/s for oil return.

5. Pressure Problems: High vs Low – Diagnosis Table

Problem	Possible Cause	Solution
High Pressure	Dirty condenser, overcharge, or fan malfunction	Clean condenser, check airflow, adjust charge
Low Pressure	Leak, valve restriction, or low load	Leak test, valve adjust, load balance
Fluctuating Pressure	Moisture or blocked filter-drier	Replace drier, vacuum system, recharge

6. Energy Efficiency, Maintenance & Troubleshooting

Efficiency depends on condenser cleanliness, fan function, and refrigerant charge. Proper calibration ensures optimal performance.

• Check suction/discharge pressures weekly
• Clean condenser fins
• Replace filters every 2,000 hours
• Re-tighten electrical terminals
• Verify compressor amperage draw

Common issues:

Symptom	Likely Cause	Solution
Ice not forming	Low refrigerant charge	Leak test and recharge
Ice too thin	Overfeeding TXV	Adjust superheat
Compressor overheating	Poor condenser airflow	Inspect fan and clean fins

7. Safety, Environmental Care & Technical Notes

Always handle refrigerants responsibly using recovery systems and PPE. Avoid mixing gases or non-approved oils to prevent corrosion.

• Use low-GWP refrigerants
• Implement heat recovery systems
• Recycle copper and aluminum components

TAMUTOM continues to develop advanced flake ice machine solutions with improved durability and energy efficiency, exporting to over 90 countries worldwide.

8. Conclusion

Flake ice machines combine thermodynamics, precision control, and advanced mechanics. Maintaining proper refrigerant levels and airflow ensures maximum reliability. TAMUTOM remains committed to innovation and sustainable manufacturing practices.