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Liquid Nitrogen for Ground Freezing
Operational Continuity with LIN Lances from Linde
Use our liquid nitrogen (LIN) supply and control solutions to freeze critical ground areas around construction sites and stabilize the soil for safety and engineering benefits
Leveraging Gases to Accelerate Workflows on Construction Sites
Unstable soil and loose sediment can pose serious safety and operational challenges during underground and tunnelling work. The ground must be safely stabilized so it will not collapse during excavation and subsequent construction work. One way of achieving this is by freezing critical ground areas with nitrogen (N2).
Lances are inserted into the ground and flushed with liquid nitrogen (LIN). The frozen areas around the lances increase the static load-bearing capacity and the impermeability of the ground. This allows tunnelling and boring work to continue safely.
We have developed a wide portfolio of innovative lances with different freezing zone profiles using LIN to meet different ground freezing, excavation and soil stabilization challenges with the help of liquid nitrogen.
Benefits at a Glance
- Innovative lance portfolio offering an ideal fit for different freezing challenges
- Easy handling and optimum freezing performance
- Rapid withdrawal in the case of removable lances
- Access to our in-depth knowledge of and experience in ground-freezing applications
- Assistance in positioning lances for the most effective freezing performance
- Support during project set-up, installation and gas supply
- Customization of lance installations to the individual ground-freezing requirements
- Support with LIN handling and safety instructions
Typical Application Scenarios
- Soil stabilization around excavation pits and tunnels
- Ground water cutoff
- Recovery of tunnel boring machines (TBMs)
- Stabilization after collapses
- Temporary ground improvements
- Temporary underpinning
- Environmental projects such as removal of contaminated soil or avoidance of permanent impact on groundwater pathways
AGF Eco - A Closer Look
Highlights of our lance portfolio include our AGF Eco lance with its distinctive fade-out zone towards the top of the lance. With AGF Eco, the frost body develops along the full length of the freezing lance inserted into the ground. This extended chill zone reduces the amount of heat that can permeate from the surface down to the area of interest. It also warms up the exhaust gas that is vented at the point of use so there is less build-up of cryogenic fog. By utilizing the liquid nitrogen more efficiently and extending the frost body, AGF Eco reduces the volume of liquid nitrogen needed.
AGF Trim Lance - How it Works
Our innovative lance portfolio also includes a removable freezing lance for tunnelling and pipe jacking applications. This was designed to overcome the problems that can arise as tunnel boring machines (TBMs) approach lances. Accidental collisions can result in emergency stops, costly and time-consuming repair work and subsequent project delays. Our removable lances overcome this challenge. They are simply disconnected from the liquid nitrogen (LIN) supply and quickly defrosted before the TBM arrives. Only a very small area around the lances is defrosted so they can be easily pulled out from the ground by crane. The frozen ground is not affected and remains completely frozen, allowing tunnelling work to progress safely.
