Mobile Brine Cooling System

Special Container Refrigeration System for Ground Freezing

Mobile brine cooling system in a special container, designed as a CO₂ / NH₃ cascade refrigeration system and equipped with piston compressor units. 

To avoid the problem of infiltrating groundwater in deep construction projects, ground freezing of underground areas is often used. 

ARCTOS offers the possibility to freeze the soil around or above the construction site with its ground freezing units. The ice shield protects the construction site from groundwater infiltration during the construction period and provides static reinforcement.

Special Container with Ground Freezing Unit

The mobile brine cooling system is installed in a special container and equipped as a cascade refrigeration system with piston compressor units. 

The refrigerants used are NH₃ in the lower and CO₂ in the upper cascade stage. The CO₂ / NH₃ cascade refrigeration system is used for cooling a brine (CaCI₂, 30%). 

This is used for freezing the ground (frozen mass), including for the creation of tunnel boring cross sections. 

The chosen design as a cascade refrigeration system was selected to allow for deeper cooling if necessary. However, a different coolant carrier is required for this. The cooling limit for TYFOXIT F 50 is -50 °C, compared to approximately -45 °C for 30% CaCl₂.

Why a Cascade Refrigeration System?

The cascade refrigeration system is often used when low temperatures need to be generated economically. 

In this setup, a low-temperature refrigerant (e.g., CO₂) is used in the lower cascade stage's cycle. 

The evaporator of this stage acts as the condenser for the upper cascade stage, which contains a different refrigerant (e.g., NH₃). 

Thanks to the well-matched evaporation and condensation properties, low temperatures and favorable pressure conditions for the compressors can be achieved.