Ammonia Evaporator for Vegetable Freezing Tunnel

Ammonia Evaporator for Vegetable Freezing Tunnel

An ammonia evaporator for a vegetable freezing tunnel is a crucial component in the refrigeration system of the tunnel freezer. It plays a vital role in the rapid freezing process of vegetables, helping to maintain the quality and freshness of the frozen vegetables.

The ammonia evaporator works based on the principle of vapor - compression refrigeration. Ammonia, a refrigerant, enters the evaporator in a liquid state. As it evaporates, it absorbs heat from the surrounding air or the objects in contact with the evaporator, causing the temperature in the freezing tunnel to drop. This process enables the rapid freezing of vegetables. The ammonia vapor then returns to the compressor to complete the refrigeration cycle.

Structural Characteristics

Tube - fin Structure: Usually, it adopts a tube - fin structure to increase the heat transfer area. The tubes are made of stainless steel or galvanized steel, which have good corrosion resistance and heat transfer performance. Aluminum fins are attached to the tubes to enhance heat dissipation. The fin spacing can be adjusted according to different requirements, generally ranging from 4mm to 20mm.

Blower Assembly: It is equipped with a blower to force air circulation. The blower can make the cold air flow evenly in the freezing tunnel, ensuring that the vegetables are evenly cooled. Some evaporators also have adjustable air - guiding devices to better control the air flow direction and distribution.

Defrosting Device: To prevent frost from building up on the evaporator surface, which would affect heat transfer efficiency, an ammonia evaporator is usually equipped with a defrosting device. Common defrosting methods include electric defrosting, hot - gas defrosting, and water defrosting.

Advantages in Vegetable Freezing Tunnels

High Cooling Efficiency: Ammonia has a large latent heat of vaporization, which means it can absorb a significant amount of heat during the evaporation process. This allows the ammonia evaporator to quickly lower the temperature in the freezing tunnel, achieving a fast - freezing effect for vegetables and helping to maintain the original quality, color, and nutritional value of the vegetables.

Good Heat Transfer Performance: The tube - fin structure and the excellent heat transfer properties of ammonia enable efficient heat exchange between the evaporator and the surrounding air. This ensures that the cold energy is effectively transferred to the vegetables, improving the freezing efficiency.

Low Cost: Compared to some other refrigerants, ammonia is relatively inexpensive. This helps to reduce the operating cost of the vegetable freezing tunnel, making it more economically viable for large - scale vegetable freezing operations.