An interesting feature of the engine was a regenerator system to recover heat from the gases leaving the power turbine, using this heat to preheat the air on its way from the compressor to the combustor. The benefits of this were to improve fuel efficiency and reduce the final exit temperature of the exhaust. The regenerators involved some sort of rotating disks which somehow transferred the heat as they rotated. There are diagrams/animations depicting the gas flow through the engine and (generally) heat path through the regenerators, but in some ways they don't seem to make much sense.
My question is: how did the regenerator setup actually work? How was the compressor output air (60 psi?) put into contact with a rotating(?) hot surface without the pressure leaking air away to the exhaust? Why would a regenerator need moving parts at all? Could it not just be a system of tubes within tubes?