Mar 26, 2023

What is Vacuum Jacketed Piping: Understanding How It Works and Its Benefits in Cryogenics

Vacuum jacketed is a type of insulation technique used to maintain extremely low temperatures of substances like liquid nitrogen. It consists of two layers of metal separated by a vacuum. The outer layer is typically made of stainless steel and the inner layer is made of aluminum. The vacuum layer between them provides excellent insulation against heat transfer from the outside.

A photo of a cutout section of vacuum-jacketed piping, revealing the inner and outer pipes separated by an insulating layer. The pipes appear to be made of metal, and various valves and connectors are visible along the length of the piping — Image Source www.cryocomp.com/

This vacuum jacketed insulation technique is used for liquid nitrogen because liquid nitrogen has an extremely low boiling point of -196°C (-321°F). This means that even small increases in temperature can cause it to boil off and evaporate rapidly. This is why it needs to be stored at very low temperatures to keep it in its liquid state.

Vacuum jacketed insulation provides an effective barrier to heat transfer, which helps to keep the liquid nitrogen at a constant temperature. This makes it ideal for use in cryogenic applications such as medical, scientific, and industrial processes where low temperatures are required. Vacuum jacketed containers are also used to transport liquid nitrogen safely over long distances without significant evaporation.

A photo of a vacuum jacketed pipe system used for transporting cryogenic fluids. The system consists of two parallel pipes separated by an insulating layer and enclosed in a vacuum jacket. Various valves and connectors are visible along the length of the pipes, and the system appears to be mounted on a support structure — Image Source www.cryocomp.com/

There are several types of vacuum jacketed systems, each with its own advantages and disadvantages. The following are some of the most common types of vacuum jacketed systems:

1. Single-walled vacuum jacketed system: This is the simplest type of vacuum jacketed system, consisting of a single-walled container that is sealed and evacuated to create a vacuum. The container is then surrounded by a jacket that is also evacuated to minimize heat transfer. However, this type of system is not very effective at maintaining a low temperature and is typically only used for short-term storage.

2. Multi-layered vacuum jacketed system: This type of system consists of multiple layers of insulation, each separated by a vacuum. The layers can be made from different materials, such as glass or metal, and can be designed to maximize thermal insulation. This type of system is more effective than a single-walled system at maintaining low temperatures but can be more expensive.

3. Cryogenic vacuum jacketed system: This type of system is designed for storing and transporting cryogenic fluids, such as liquid nitrogen or helium. It typically consists of a double-walled container with an inner layer that contains the cryogenic fluid and an outer layer that is evacuated to minimize heat transfer. This type of system is very effective at maintaining low temperatures but can be expensive and requires specialized equipment.

4. Vacuum jacketed piping system: This type of system is used for transporting cryogenic fluids over long distances. It consists of insulated piping that is surrounded by a vacuum jacket to minimize heat transfer. This type of system is effective at maintaining low temperatures over long distances but can be expensive and requires specialized equipment.

The best vacuum jacketed system depends on the specific application and requirements. For short-term storage or moderate temperature control, a single-walled or multi-layered system may be sufficient. For cryogenic fluids or long-distance transport, a cryogenic or vacuum jacketed piping system may be more appropriate. The choice of system will also depend on factors such as cost, efficiency, and ease of use.