Evaporator Coil for Strawberry IQF ( ＋15/-18)

Evaporator Coil for strawberry IQF ( ＋15/-18)

An evaporator coil for IQF (Individually Quick Frozen) strawberries operating at temperatures of +15°C to -18°C serves as a critical component within a freezing system. It is specifically designed to remove heat from the strawberries, causing them to freeze quickly while maintaining their individual integrity. Here's how an evaporator coil for strawberry IQF works in this context:

1. Heat Absorption: The evaporator coil is filled with a refrigerant, often a low-temperature coolant like ammonia or a modern refrigerant like R404A. The refrigerant enters the coil as a low-pressure, low-temperature gas.

2. Expansion Valve: Before entering the coil, the refrigerant passes through an expansion valve, where it rapidly expands, leading to a drop in temperature and pressure. This cold, low-pressure refrigerant is then sent into the evaporator coil.

3. Heat Transfer: The strawberries, which are typically placed on a conveyor belt or a mesh belt, are moved through or around the evaporator coil. As the strawberries come into contact with the cold coil, heat from the strawberries is rapidly transferred to the refrigerant inside the coil.

4. Phase Change: The heat transfer causes the refrigerant to evaporate, changing from a liquid to a gas phase. This phase change is an endothermic process, meaning it absorbs heat from the strawberries, thereby cooling them down.

5. Quick Freezing: Due to the efficient heat transfer, the strawberries quickly drop in temperature and freeze individually. The IQF process ensures that each strawberry is frozen separately rather than forming a solid block, preserving their quality, texture, and taste.

6. Refrigerant Evaporation: The now gaseous refrigerant exits the evaporator coil and returns to the compressor, where it is compressed, raising its temperature and pressure.

7. Refrigeration Cycle: The compressed refrigerant is then sent to the condenser where it releases the heat absorbed from the strawberries to the surroundings, causing it to condense back into a liquid. The high-pressure liquid refrigerant is then throttled through an expansion valve, and the cycle repeats.

The specific design and capacity of the evaporator coil depend on factors such as the desired freezing rate, the quantity of strawberries to be frozen, and the specific refrigeration system used in the IQF process. Efficient evaporator coils are crucial for maintaining the quality of the strawberries and ensuring a rapid and consistent freezing process. Proper control systems are also used to regulate the coil temperature and optimize the IQF process.