Refrigerator semi-trailers fundamentals
If there are temperature requirements for the cargo, it should be transported in a refrigerated vehicle. A good option is to use a refrigerator semi-trailer in combination with a tractor unit. An isothermal body of a semi maintains the required temperature (from -20C to +12C) that is provided by a special cooling apparatus. Such conditions are good enough to transport perishable and chilled foodstuff, medicines, flowers, etc.
It’s evident that a refrigeration unit is the key element here. It can be powered either by the tractor’s engine or by its own separate combustion engine. These alternatives depend on the stages of the route (delivery or parking). Generally, the cooling mechanism is installed at the front of a semi-trailer. The compressor and the engine of the mechanism are placed at its bottom while the condenser and the evaporator are found at the top.
- Thermal insulation is ensured by means of:
- sandwich-panels made of foam plastic, urethane plastic foam, foam polystyrene (or other similar materials);
- galvanized siding for inner surface;
- multilayer flooring, covered with sheet metal;
- hermetic doors.
There are 2 types of refrigerated semi-trailers according to the presence/absence of a solid frame. The choice depends on the quality of the roads. The vehicles without the frame can be operated only in case of reliable road pavement while the presence of the frame makes machinery resistant to the pavement of bad quality.
The use of special equipment inside a refrigerated body adjusts it in accordance with the set of tasks. Thus, after installing ceiling hangers it’s possible to transport chilled carcasses. Double-decked and multisectional structures are used to optimize the haulage process, as the sections can have different temperature levels for different kinds of freight.