Cryogenic containers are equipment for storing and transporting cryogenic liquids, and their working principle mainly relies on insulation materials and vacuum layers to reduce heat conduction and radiation to keep the liquid at a low temperature. The following are the main principles of cryogenic container operation:
Insulation
The shell of a cryogenic container is usually composed of multiple layers of insulation materials with low thermal conductivity, such as polyurethane foam, glass fiber, perlite, etc., which can effectively reduce the conduction of external heat to liquids.
Vacuum layer
There is usually a vacuum layer on the outside of the insulation to reduce convection and radiation for heat transfer. There is no gas or air in the vacuum layer, so the heat transfer path is cut off and the heat cannot be conducted to the interior by way of convection.
Liner
The liquid is stored in an inner tank inside a vacuum. The liner is usually made of stainless steel or other low-temperature materials with good sealing and corrosion resistance. The design of the liner can be adapted to the nature of the liquid and storage needs.
Cooling unit (for some cryogenic vessels)
Some cryogenic vessels also have cooling devices inside, such as refrigeration units, liquid nitrogen or liquid oxygen supply systems, etc. These devices can remove heat from the liquid by conduction or convection, keeping it cold.
Tightness & Safety Systems
To ensure the safety of liquids during storage and transportation, cryogenic containers are often designed with a double-walled layer to enhance tightness and heat retention, as well as safety valves and leak alarm systems. As soon as the internal gas pressure and temperature exceed the normal range, these systems are able to detect and take action in time.
To sum up, cryogenic containers can effectively maintain the low temperature state of the liquid through the structure of insulation materials, vacuum layers, inner tanks and cooling devices, and ensure the stability and safety of the liquid during storage and transportation. At the same time, the tightness and safety system ensure the safety of the operation.
