Cold Storage
- Cold storage plants are specialized refrigeration systems designed to store perishable goods at low temperatures to prevent spoilage. They are widely used in food preservation, pharmaceuticals, and industrial applications.
- Parts & Construction
| Component | Function |
|---|---|
| Compressor | Compresses refrigerant and circulates it through the system. |
| Condenser (Air/Water-Cooled) | Dissipates heat from refrigerant to the surrounding. |
| Expansion Valve | Regulates refrigerant flow into the evaporator. |
| Evaporator Coil & Fan | Absorbs heat from stored products, cooling the space. |
| Insulated Walls & Doors | Prevents heat transfer and maintains low temperature. |
| Defrost System | Removes ice buildup on the evaporator coil. |
| Temperature & Humidity Sensors | Monitors and controls storage conditions. |
| Electrical Controls & Circuit Panel | Manages the automation and safety of the system. |
- Types of Cold Storage & Applications
| Type | Temperature Range | Applications |
|---|---|---|
| Chiller (0°C to 5°C) | Dairy products, fruits, vegetables. | |
| Frozen Storage (-18°C to -25°C) | Meat, seafood, ice cream. | |
| Deep Freezing (-30°C to -60°C) | Vaccine storage, long-term food preservation. | |
| Blast Freezers (-40°C to -50°C) | Quick freezing of food products. | |
| Controlled Atmosphere Storage | Apples, bananas, grapes (controlled oxygen & CO₂ levels). |
- 4. Preservation by Refrigeration
- Food spoiling agents include bacteria, yeast, mold, and oxidation. Cold storage prevents spoilage by:
✅ Lowering temperature to slow microbial growth.
✅ Controlling humidity to prevent dehydration and mold formation.
✅ Maintaining proper ventilation to distribute cold air evenly. - Storage Temperature for Different Products
| Product | Storage Temperature |
|---|---|
| Milk & Dairy | 0°C to 4°C |
| Fruits & Vegetables | 1°C to 10°C |
| Meat & Poultry | -18°C to -25°C |
| Ice Cream | -30°C to -35°C |
- Mobile Refrigeration in Transport Vehicles
- Used in trucks, containers, and ships to maintain required temperature during transportation.
- Refrigeration Unit Types:
- Active Cooling (Compressor-based systems) – Used for frozen foods & dairy.
- Passive Cooling (Dry ice, Gel packs) – Used for medical shipments.
- Pressure Testing, Evacuation & Charging Process
- 🔹 Pressure Testing: Ensures there are no leaks in the refrigerant circuit.
🔹 Evacuation: Removes moisture and air from the system using a vacuum pump.
🔹 Charging: Refrigerant is filled into the system based on manufacturer specifications.
🔹 Efficiency Testing: Ensures temperature control, proper insulation, and energy efficiency.
- Common Troubleshooting in Cold Storage
| Problem | Possible Cause | Solution |
|---|---|---|
| High Temperature | Insufficient refrigerant, faulty compressor | Check refrigerant level, service compressor |
| Ice Buildup | Defrost system failure | Check defrost heater and timer |
| High Energy Consumption | Dirty condenser coil, poor insulation | Clean condenser, improve insulation |
| Uneven Cooling | Blocked air circulation, fan failure | Check and replace fans |
- Freezing Techniques
- 🧊 Deep Freezing (-30°C to -60°C): Used for long-term storage.
🌀 Freezing Tunnel (Blast Freezer): Rapid freezing of products using high-speed airflow.
💨 Shock Freezing: Flash freezing at extreme temperatures to retain food quality.
- 🧊 Deep Freezing (-30°C to -60°C): Used for long-term storage.
