The ZrFe bed is a pressure vessel charged with a zirconium alloy that has a high capacity for hydrogen isotopes. As an inert gas stream containing tritium passes through the bed, the bed absorbs the hydrogen.
The mass transfer zone of the bed is short by comparison to the bed length for the operating conditions specified. Once the bed is loaded and the mass transfer zone penetrates the bed exhaust, the activity of the gas leaving the bed rises gradually which provides sufficient warning to operators that the bed is exhausted.
Regenerations can be performed by directing a heated inert purge stream through the scavenger bed in the reverse direction to recover the hydrogen for purification and re-use. The ZrFe bed heaters can be engaged to provide additional heat of desorption to the system and to reduce the regeneration time. Typically, the bed is ready for re-use once 9000 bed volumes of gas are passed through while it is at the regeneration temperature of 540˚C.
The ZrFe Bed is designed for robustness. The stainless steel welded vessel, rugged band heater, sheathed thermocouples, insulation and protective stainless-steel jacket ensure a clean package that can operate continuously at 540oC without damage.
The ZrFe Bed comes standard with metal bellows isolation hand valves fitted with copper stem tips and VCR-8 female nuts. The unit is helium leak tight to 1×10-9 scc/sec at the operating temperature which is suitable for tritium service.