We are implementing a system to recover helium from our Janis ST-500 continuous flow LHe cryostat. The recovery system uses standard 1/4″ plastic tubing, which we connect directly to the cryostat’s exhaust port. The problem with this setup is that the gas is still quite cold as it leaves the cryostat. The tube quickly ices over, providing additional thermal insulation, and we soon have a tail of ice many feet long.
Do you know of any heat exchangers that would use room-temperature nitrogen to bring the helium to above 0°C? We would like to contain the ice accumulation to a small drip tray that can be placed under the cryostat exhaust. Any cleverer solutions would, of course, also be appreciated.
CSA Archive 
We use a simple and inexpensive coil of copper tubing as a heat exchanger on our cryogen lines when we need to go from liquid to gas. The coils are oriented vertically and have 10 to 15 turns. Place a drip pan underneath. Add a fan and more turns if you need to raise the temperature higher.