What Are The Classifications Of Refrigerated Containers

A refrigerated container refers to a container with insulated walls (including end walls and side walls), a door, a bottom and a top, which can prevent heat exchange between inside and outside. Refrigerated containers include refrigerant-consuming reefer containers, mechanical reefer containers, refrigeration/heating containers, insulated containers, and controlled atmosphere reefer containers.

Consumption refrigerant type refrigerated container

Refrigerant-consumed refrigerated containers generally refer to various refrigerated containers that do not require external power or fuel supply, including water-ice refrigerated containers, dry ice refrigerated containers, liquid nitrogen refrigerated containers, liquid air refrigerated containers, liquid carbon dioxide refrigerated containers, and cold plate refrigerated containers Wait. The characteristics of refrigerant-consuming reefer containers are that they do not require external power or fuel supply during transportation, have no moving parts, and require low maintenance. The main disadvantage is that continuous refrigeration cannot be realized. The refrigerant must be recharged or supplemented after heat release and consumption. It is difficult to achieve precise temperature control and the refrigeration equipment takes up a large space. The refrigerant-consuming refrigerated container is mainly suitable for short-distance transportation of small refrigerated containers. Refrigerated containers that consume refrigerant are only used in regional short-distance refrigerated transportation, but are no longer used in international refrigerated transportation and have a tendency to be phased out.

Mechanical refrigerated container

Mechanical refrigerated containers refer to refrigerated containers equipped with refrigeration devices (such as compression refrigeration units, absorption refrigeration units, etc.). Mechanical refrigerated container is a refrigerated container with mature technology and many applications. Compared with other refrigerated containers, it has the following advantages:

①The temperature adjustment range is wide, from normal temperature to about -30℃. Strong versatility, can transport goods with different temperature requirements;

②Convenient automatic control;

③The temperature distribution in the box is relatively uniform:

④It is suitable for long-distance transportation, which is its outstanding advantage over other forms of refrigerated containers.

Mechanical refrigerated containers also have some disadvantages: such as complex equipment, large initial investment, and high maintenance costs; the temperature gradient in the box is greater than that of liquid nitrogen refrigerated containers; fans and air duct systems are required in the box, which will increase the dry consumption and dehydration of the goods in the box .

Refrigeration and heating container

The refrigeration and heating container refers to a refrigerated container equipped with a refrigeration device (mechanical refrigeration or refrigeration using refrigerant) and a heating device. This kind of container not only has a refrigerating device, but also a heating device. Cooling or heating means can be adopted as needed to control the temperature in the refrigerated container within the set range. Generally, the temperature range in the container is -18℃～38℃ .

Insulated container

Insulated container refers to a refrigerated container without any fixed and temporary additional cooling and or heating equipment. Insulated containers have good thermal insulation performance. In order to achieve its thermal insulation function, external cooling or heating equipment must be provided to deliver cold or hot air into the box to achieve the purpose of insulation.

The characteristic of the insulated container is the simple structure of the container itself, the high effective loading volume rate of the container and the low cost. It is suitable for transporting large quantities of frozen or refrigerated goods of the same variety on fixed routes. The disadvantage is the lack of flexibility and high requirements for related supporting facilities on the entire transportation route.

Insulated containers used to be one of the main means of transportation of refrigerated and fresh-keeping goods in the world before the 1970s. With the large-scale use of mechanical refrigerated containers after the 1980s, insulated containers have gradually become more flexible mechanical Replaced by refrigerated containers, but still in use on certain routes with stable supply.

Modified atmosphere refrigerated container

The air-conditioned refrigerated container has all the refrigeration functions of a general mechanical refrigerated container, and is equipped with an air-conditioned device that can adjust and control the air composition in the box to reduce the breathing intensity of fresh fruits and vegetables, thereby slowing down the ripening progress of fruits and vegetables, and achieving freshness the goal of.

The key to modified atmosphere preservation is to regulate and control the content of various gases in the cargo storage environment. It is common to use nitrogen filling and oxygen reduction methods to reduce the oxygen content in the environment, control the ethylene content, and slow down the ripening of fruits and vegetables. Air-tightness requirements of air-conditioned refrigerated containers are relatively high, and the air leakage rate is generally required to not exceed 2m³/h.

Modified atmosphere refrigerated container transportation has the advantages of good preservation effect, less storage loss, long preservation period and no pollution to fruits and vegetables. However, due to the high technical requirements and the high price of refrigerated containers after the use of air-conditioning equipment, the use is not widespread.

Other refrigerated containers

In addition, there is a low-pressure refrigerated container similar to the modified atmosphere refrigerated container, which stores and transports fruits and vegetables in a low-pressure environment. The pressure inside the box is 1333～10666 Pa, the relative humidity is 90%～95%, and the temperature is 2℃～+16℃. The oxygen content is (0.1±0.03)%, and ventilation is required to limit ethylene and other harmful gases. The low-pressure refrigerated container consists of a refrigeration system, a vacuum system and a power system. The refrigeration system is used to reduce the temperature; the vacuum system is used to remove the air and water vapor in the tank; the power system is used to generate electricity by diesel fuel and provide electricity for the container.

The other is a jacketed refrigerated container. This kind of refrigerated container is characterized by a channel for cooling air circulation along the wall-jacket. The advantage of this kind of refrigerated container is that the loading of goods does not affect the circulation of air, and therefore does not affect the temperature distribution; secondly, the entire volume of the jacket space is used for loading goods, which is very advantageous for the shipment of low-density goods. This kind of container cannot contain breathing goods, and is generally used to ship frozen goods.