The Cryomech HeRL01-RM Makes Helium Recovery Cost-Efficient for All NMR Labs
As the cost of liquid helium used to cool NMR magnets continues to rise, the case for helium recovery systems is becoming stronger. However, large-scale helium recovery doesn’t make economic sense for single NMR setups. For such systems, strict vibration sensitivity requirements, as well as high installation and energy costs, have been barriers to investing in direct helium recovery – until now.
Nuclear magnetic resonance (NMR) spectroscopy is widely used by commercial and academic researchers to determine the molecular structure of organic compounds. At the heart of an NMR system is a superconducting coil, used to generate a strong magnetic field, which is cooled to 4.2 K using liquid helium. Each helium fill can last from one to six months depending on the thermal losses and size of the dewar.
Despite these potentially long retention times, the fluctuating availability and increasing cost of liquid helium have made recovering this resource an increasingly attractive option for NMR laboratories. However, conventional systems haven’t been economical for smaller NMR setups with low helium boil-off rates. Bluefors has developed the HeRL01-RM Helium Reliquefier to address this issue by combining a compact design with low energy consumption that brings the benefits of helium recovery to smaller NMR systems.
Making Closed-Cycle Helium a Reality for All NMR Systems
The HeRL01-RM was specially designed for NMR labs with one or two magnets and boil-off rates of under one liter per day. It builds on the proven technology of the Cryomech HeRL02-RM, which was launched by Bluefors in 2024 and represented a groundbreaking step forward because it made helium recovery from single NMR systems a viable, efficient option.
The HeRL02-RM met the strict vibration sensitivity requirements and cost significantly less to install and run than a centralized recovery system. While this has enabled many NMR systems to transition to closed-cycle helium recovery, the recovery rate exceeds the boil-off rate of most modern NMR magnets. The HeRL01-RM builds on the proven strengths of the HeRL02-RM by optimizing the technology for magnets with lower helium consumption.
Exceptional Energy Efficiency Makes Helium Recovery Viable for Smaller NMR Systems
Just like the HeRL02-RM, the new HeRL01-RM turns the NMR magnet into a closed-cycle, zero boil-off helium condensing system. The helium gas rises from the cryostat through natural convection and is captured by the reliquefier, where a two-stage pulse tube cryocooler cools and recondenses it. The resulting liquid helium drips back into the cryostat, with a 100% recovery rate that maintains consistent liquid helium levels.
The key to making this approach economical even for systems with lower boil-off rates is the exceptional energy efficiency delivered by the HeRL01-RM’s smaller cryocooler. Designed specifically for smaller systems, it features a more compact and efficient cold head design, and a smaller liquefier with improved insulation for reduced heat loss.
These technical advances result in significantly reduced power input, enabling the use of single-phase electricity, making the reliquefier easier to integrate into a wider range of laboratory environments and reducing long-term operating costs. The power input reduction— to as little as 4.0 kW at 60 Hz—also reduces electrical costs by about 20% compared to the HeRL02-RM. For most NMR users, this lowers annual operating costs to about 30% less than the cost of purchasing liquid helium, making the reliquefier a cost-effective solution for lower MHz single spectrometers.
Proven Protection from Unwanted Vibrations
Energy efficiency is only part of the equation. A critical requirement of any reliquefier is that it does not cause mechanical vibrations, because vibrations and noise can obscure and affect NMR experiment results. Signals emitted by specific atomic nuclei as they resonate in a magnetic field are represented as peaks in NMR spectra, plotting the results on chart. The amplitude of the useful signal coming from the sample in an NMR is very small, which means electrical or mechanical noise (vibrations) can overpower the signal so the user cannot make out the useful peaks from the random unwanted noise.
NMR calibration and verification is performed through a test of 1% chloroform in Acetone-d6. This test is extremely sensitive to mechanical vibration because the signal decay is about 10 seconds, much longer than typical experiments which have a decay time of less than one second.
Just like the HeRL02-RM, the new HeRL01-RM utilizes a remote motor suspended from cloth straps to minimize vibrations that might otherwise interfere with sensitive NMR spectroscopy. This setup has been field tested on multiple systems of varying magnet strength and shown to have no effect on experiment results.
The result of one such test is shown below. The green line is a test before installing the HeRL01-RM and the yellow line is after. Although vibrations from the HeRL01-RM are evident, the magnitude of the noise is about half of the magnitude of the useful peaks. This is considered an acceptable level for NMR users and will likely not be detectable at all during most experiments which have a much faster signal decay.
Secured Helium Availability and Stable Operating Costs
With its reduced power requirements and compact design, the Cryomech HeRL01‑RM makes it easy for laboratories with smaller NMR systems to adopt helium recovery. By enabling closed‑loop, zero‑boil‑off helium recovery for NMR magnets, the HeRL01‑RM reduces dependency on helium deliveries, stabilizes operating costs, and helps to ensure that magnets keep working without interruption.
Designed to easily integrate directly with NMR systems, the HeRL01-RM manages helium recovery automatically, so users can focus on their research rather than refills.
Contact us to find out how you can take control of your helium with the HeRL01-RM and enjoy the benefits of closed-loop helium recovery.