Helium Liquefier – Bluefors LHEP22 System
✅ Manufacturer: Bluefors Cryocooler Technologies, Inc. (formerly Cryomech)
✅ Core Functionality:
- Converts helium gas into liquid helium for MEG system cooling.
- Uses pulse-tube cryocooler technology for high efficiency with low vibration and noise.
- Daily Production: Over 22 liters of liquid helium per day.
- MEG Consumption: ~11 liters per day, allowing for excess capacity to manage losses.
- Compressor: CPA1110 powers the system.
- Cold Head: PT415 sits atop a 150-liter cryogenic Dewar for liquid helium storage.
Helium Recovery & Storage System
✅ Gas Collection & Storage
- Captures helium boil-off from the MEG system, particularly during refills or horizontal positioning for specific experiments.
- Uses a CPA286R compressor to transfer gas into two 1500-liter storage tanks at up to 100 psig.
- Collected helium is slowly reintroduced into the liquefier via a purification process.
✅ Custom MEG Interface
- Designed with non-magnetic components to prevent interference with MEG signals.
- Hoses, valves, pressure regulators, and heat exchange finned tubes warm helium gas to room temperature before reaching the recovery compressor.
- An electrical insulator at the recovery line entry point prevents electromagnetic noise contamination in the magnetically shielded MEG room.
Helium Purification System
✅ How It Works:
- Incoming helium gas passes through a liquid nitrogen-based purifier.
- Liquid nitrogen (−196 °C / −320 °F) traps contaminants such as:
- Oxygen (liquifies at −183 °C / −297 °F)
- Carbon dioxide (freezes at −78 °C / −109 °F)
- Purified helium is then reintroduced into the liquefier, ensuring high purity and efficiency.
Sustainability & Operational Benefits
✔ Significant cost savings by reducing the need for external helium refills.
✔ Minimizes environmental impact through helium recycling.
✔ Ensures continuous MEG operation without helium shortages.
✔ Low-maintenance, vibration-free system for stable and reliable MEG signal acquisition.