...
We get the best transfer efficiencies when the transfer lines from the Liquifier to the magnet are sufficiently cold. We have tested two modes (paths) to pre-cool the system: the slow and the fast pre-cooling as well as a combination of these two modes which allows us to reduce the slow pre-cooling time.
The fast pre-cooling transfer efficiencies are about 47-49% which does not allow filling the entire magnet volume using just one Liquifier. Nevertheless, higher efficiencies of about 54% can be obtained with the fast pre-cool if the Liquifier pressure is reduced to 3.5 PSI at the expense of nearly 2 hours (~8L) where the Liquifier is not producing while reaching the set pressure. Although the fast pre-cooling has a lower transfer efficiency the procedure could be performed when the magnet needs to be filled immediately and the slow pre-cool hasn't been done because none of the Liquifiers are near full.
The slow pre-cooling has consistently given higher transfer efficiencies between 56 and 58% but requires long pre-cooling times (~ 4 to 5 hours) with the potential benefit of a slow filling which is still under study. During the slow pre-cooling, we can estimate when the system is cold enough through the behavior of the Tank T temperature.
The The reported efficiency values were obtained by performing the magnet fills from the seam to the level probe spike.
The different pre-cooling procedures are given below. Please confirm with the target expert the pre-cooling mode to be conducted.
Slow pre-cooling:
1. Enable the Flow PID control of the Magnet Return Bypass at 65 slm.
...