Refrigerated Containers: Operation and Technique

What is a Reefer Container and How Does It Work?

In the realm of global trade, transporting perishable goods represents a crucial logistical challenge. As distances and travel times increase, maintaining the freshness and quality of highly sensitive products such as fresh food, pharmaceuticals, and cosmetics becomes a daunting task. This is where refrigerated containers, also known as reefer containers, come into play.

These sophisticated transport systems are not just simple refrigerated boxes. They are true mobile refrigeration units, designed to maintain strictly controlled temperatures throughout the entire shipping journey. Inside a reefer container, the air is constantly cooled and circulated through the cargo thanks to an integrated refrigeration system powered by electricity.

Temperature Control, Ventilation, and Atmosphere

The heart of a refrigerated container is its refrigeration system with electric compressors. These sophisticated systems continuously remove excess heat from inside the container, keeping the temperature within a preset range, typically between -30°C and +30°C. Some specialized models can even reach cryogenic temperatures down to -60°C, ideal for transporting ultra-sensitive vaccines and biological samples.

However, temperature control is just one of the key aspects of refrigerated containers. Adequate ventilation is equally crucial to ensure an optimal environment for the cargo. A sophisticated system of ducts and fans circulates the cold air evenly throughout the container, pushing it under the cargo through a specially designed T-shaped flooring. This unique design maximizes airflow, minimizing the formation of hot or cold spots.

For particularly delicate goods, like fresh fruit, an additional factor to control is the internal atmosphere. Modern ATP containers (Agreement on the International Carriage of Perishable Foodstuffs) have systems to monitor and adjust not only the temperature but also the humidity and the composition of gases such as oxygen and carbon dioxide. This helps slow down the ripening processes and extend the preservation of products that release gases like ethylene during transport.

Advantages and Disadvantages of Reefer Containers

Adopting refrigerated containers in global supply chains offers numerous significant advantages over traditional transportation methods for perishable goods. One of the main strengths is the flexibility of transport. Unlike fixed refrigeration units, these mobile containers can be easily moved on ships, trains, or trucks, allowing door-to-door transport without interruptions in the cold chain.

Another crucial advantage is the extension of the product’s shelf life. Since the cargo is kept in a controlled refrigerated environment for the entire duration of the journey, there is no need for refrigeration facilities at the destination. This significantly reduces the risk of goods deteriorating during unloading and final storage operations.

Refrigerated containers also offer the possibility to segment the interior into different temperature zones. This “multi-tenancy” thermal feature allows for the simultaneous transport of mixed loads with different refrigeration needs, such as fresh and frozen products, optimizing space and reducing costs.

Moreover, these containers are designed to withstand extreme weather conditions during maritime or land transport. Robust and highly insulated, they can maintain a stable internal environment even in the presence of external temperature or humidity fluctuations.

However, reefer containers also have some potential disadvantages to consider. Less-than-truckload (LTL) shipments can be complicated, as it is necessary to group goods with very similar temperature and atmosphere requirements. The sophisticated refrigeration and monitoring equipment also requires regular maintenance and periodic checks to ensure proper functioning.

Finally, the thermal insulation and integrated ventilation systems occupy a significant portion of the internal space, slightly reducing the available cargo volume compared to a standard non-refrigerated container.

Precautions and Best Practices for Using Reefer Containers

To fully leverage the benefits of refrigerated containers and minimize potential problems, it is essential to follow certain guidelines and best practices during loading, transport, and unloading operations.

Firstly, it is crucial to pre-cool the cargo to target temperatures before loading, as integrated refrigeration systems are designed to maintain, not lower, temperatures. The only exception is operations in air-tight refrigerated tunnels, where it is possible to pre-cool the entire container.

During loading, it is critical to correctly set the temperature, humidity, and ventilation parameters according to the product specifications being transported. An incorrect setting could compromise the integrity of the cargo, leading to premature deterioration.

Particular attention should also be paid to airflow within the container. Any obstructions, such as overly tight packaging or empty spaces between pallets and the door, can disrupt the proper circulation of refrigerated air. It is advisable to use filler materials like cardboard to seal these spaces and prevent the formation of hot zones.

Finally, but no less important, it is crucial to strictly follow the recommended sanitization procedures after each use of the container. This prevents the accumulation of residues and cross-contaminations that could compromise subsequent shipments of fresh products or pharmaceuticals.

By following these guidelines, logistics operators can maximize the effectiveness of their reefer containers, ensuring timely and optimal condition delivery of every valuable load.