Cryo Xferline Sept 22/27

email Sept 27, 2017

Jim,

Although I'm glad to help when I can, you may not be so thankful after you hear my latest thoughts.

Nesting the piping like you have for both the supply and return is effective, but I think that it will be overly complicated for these short line segments and you will be better served with a simple shield design using copper sheet metal brazed to the shield supply piping with copper braids every few feet. The supply transfer line can be directed over to the return line where the helium supply will run to the CM adjacent to the return line within a copper cylinder. The shield return will run next to the shield supply outside of the cylinder but not in contact with it.

Alternatively, you could just shield the return transfer line with this method and absorb the few extra watts into the helium supply.

Any of the methods that you choose should at least intercept the heat into the process return bayonet using braids from the shield supply (or return if the alternative method is chosen). Intercepting the heat on the process supply is probably not necessary.

Kelly