Laboratory Scale Helium Liquefaction Installations


Introduction


We define the laboratory scale Helium liquefaction installations as systems with a capacity between 18 to 50 liters of liquid helium produced per day. Quantum Technology Corp. has developed a significant number of such projects in world class research centers around the world, from design to commissioning.


These high purity recovery installations are full closed-loop systems which recover the boil-off after use, purifies it and then reliquefies it. The rate of loss of helium from the system when operating normally is almost zero.


Quantum All-Metal Installation


Quantum has successfully developed an all-metal recovery system that greatly increases the purity of the gas by avoiding the use of a gas bag. Lab-scale liquefiers can be sensitive to gas contamination (moisture, oxygen, etc) which can lead to unexpected and unwanted losses in productivity. We have developed this system specifically in response to the problems some customers were having with traditional gas bag recovery systems. It has been specially designed to ensure the highest possible gas purity enters the liquefier. This maximizes the running time of the liquefier and reduces the down-time for maintenance. The high purity is ensured by combining a cryogenic purifier and an all-metal system to prevent O2 or H2O contamination.


The system is intended for operation where the volume of gas fluctuates from day to day by using a combination of storage tanks and direct-to-liquefier piping. This means that the liquefier can be shutoff when not required and the gas can still be recovered into the storage tanks.


There are a number of safety features to prevent any over-pressure from occurring including safety shutoffs and relief valves. We will also help you to design the recovery piping to the cryostats. Quantum Technology Corp. will be there to help you design the required infrastructure (water, electrical, piping, etc) to enable quicker commissioning and smoother running of your facility.


Laboratory Scale Liquid Helium Operation


A small liquid Helium operation is shown below. Boil-off is captured both from liquid transfers and quiescent boil-off of the cryostats and is piped back to the recovery manifold. If the boil-off rate is sufficient to supply the liquefierâ™s needs, it is diverted straight through the purifier and on to the liquefier. If the boil-off rate is too low, this flow is supplemented by the gas held in the storage tanks.


Only when the boil-off rate is too great for the liquefier (during transfers for example), the recovery compressor automatically turns on, stores the excess gas, then detects when there is no more gas to recover and shuts down. This minimizes the amount of time the compressor is running which reduces both noise and cost.