Container Types- A guide to Reefer Containers

Refrigerated shipping container

Do you want to know about reefer containers? Read on.

With the advent of international trading and modernization, the logistics industry provides us with marvelous solutions to satisfy the high demands. Amongst them, reefer containers are one.

Also known as refrigerated containers, they are one of the six types of shipping containers used in freight forwarding. In simple terms reefer containers are big refrigerators used for transporting cargoes like pharmaceuticals, flowers, films in temperature-controlled environments for many miles and oceans which may otherwise perish in normal temperature.

Construction

Before we jump to how it operates, let's consider the electrical specs of the reefer unit. The control unit in the container controls the setting and adjustment of data, e.g. temperature, humidity, ventilation and the atmosphere. The unit includes:

  • Genset: Genset or the cooling generator is attached to the container to provide electricity. It is used in both ocean and shore shipping.
  • Humidity Controls: Automatic humidity sensors are mounted to monitor the moisture levels in the reefer, and open and shut the container to release excess stored water within the container. In such situations, the drains avoid the entry of the outside water and the preservation of the inner ambient humidity in order to prevent the air from drying, as this would also cause damage to fruit and vegetables.
  • Information Loggers: To guarantee moistness is spot on, information loggers are used to track air temperature, return air temperature, and surrounding temperature and humidity levels persistently owing to remote modems.

Working

Reefer containers are bottom air distribution units designed to disperse cooler air from the floor across a particular T-shaped deck, with the benefit of providing a constant and uniform air flow through the entire shipment, which is strong enough to maintain a perfect air exchange with the products. Refrigerated units can sustain or lower the temperature of your shipment, even under the most challenging circumstances. Reefer containers also fitted to 'warm-up' the products for such exports, if necessary. It is important to remember that the reefer units are not built to decrease the temperature of the cargo, but rather to preserve the pre-cooled temperature of the cargo.

Why do we need this type of containers?

Out of all the different types of shipping containers available in the market, refrigerated containers stand out due to their unique temperature controlling ability. They provide an altered environment for transportation so that the quality of the cargo is not compromised. For example, managing the amounts of CO2 and O2 in a vessel containing natural products will prolong the aging period, enabling it to be saved from stalling, and reefers can do it for you. Some products are required to be shipped chilled or solidified or in controlled temperatures.

Reefer compartments can hold the cargo at the appropriate temperatures during transit.

Apart from these, reefers have self-sufficient cooling systems, so they do not require cold storage after their arrival at the destination. They are available in various sizes and dimensions, making them ideal for all forms of transportation, road, rail, water. They can be separated into different sections and spaces at different temperatures to enable the safe transit of frozen and cooled items in one container.

Despite their many advantages, the reefer container industry also faces many obstacles. HFG refrigerants, for example, are also widely found in reefer tanks. These refrigerants have been found to be a significant contributor to global warming and there is ongoing pressure through environmental bodies and governments to limit their use. There is no reason to fear, though, as with the latest environmental drives by various nations, techniques are being carried out and built to make their transport and service eco-friendly.

Reefer Container dimensions

The size of the reefer containers varies depending on the producer. As a comparison point, LOTUS Containers has a reefer fleet consisting of 20' to 40' High Cube reefer

20ft reefer containers

  • Internal dimension- 17’10x7’6x7’5
  • External dimension- 19’10x8x8’6
  • Door opening- 7’6x7’4
  • Max gross weight- 67200 pounds

40ft high cube reefer containers

  • Internal dimension- 38’2x7’6x8’2
  • External dimension- 40x8x9’6
  • Door opening- 7’6x8’3
  • Max gross weight- 67200 pounds

Visit us at LOTUS Containers to find out more about buying refrigerated containers or dealing in different container types. With our ample of container depot partners across the world, we leave none of query unresolved.

Steri Shipment

Because of certain organic products which carry with microorganisms in them, countries such as China, Japan, Nigeria, need cold treatment, also known as Steri shipments, to import such products. With this form of shipping, the fruit would be pre-cooled to a lower temperature than the commercial market and, in order to control this, steri probes (about 3 per shipment) are inserted into the fruit pulp, within the carton.

There is a minimum threshold required for temperature variation. If the threshold is surpassed, then additional hours or days will be needed to get it to the required temperature. If one of the probes drifts beyond the tolerance, the cargo will be refused in the country of destination, due to the potential of the fruit still retaining pathogens.

All in all, cold-treatment cargoes conform with the usual shipment pattern with one or two extra criteria. If the units are packaged properly and the post-harvesting procedure is performed, until the unit fails, the cargo will be received by the customer on a ready-to-eat basis or even for further storage.

Some Helpful Tips

The below points are to be noted to make your shipments more efficient.

  • Cargo should not be filled beyond the space of the T-floor
  • Cargo should not be stuffed above the red load line
  • Cargo needs to be secure on the floor and firmly wedged so that it doesn't move throughout the passage.
  • The unit must always be set at the right loading temperature, and this set temperature can change based on the load being loaded.
  • Controls of dehumidification shall be tested
  • If pre-cooling is needed, the freight must be pre-cooled and not the container, unless the container is loaded in an airlocked cold tunnel in a cold storage container.
  • The ventilation setting plays one of the most critical functions and needs to be tailored to the right degree.
  • As air follows the simplest course of action, there should be no limits on airflow, and any openings between the pallets and the exits should be covered with carton or even wood. This will, at that stage, power the air to flow precisely and reduce the potential for heat sinks near the doors.