I wrote: I suppose you could not use it for this purpose if the water is flowing. >
For that matter, I suppose the whole problem vanishes if we assume they only use the heater when the water is not flowing. No details of the operational procedures have been released. For all we know, they turn off the flow while "firing up" the cell. They did tell me they test the flow calorimetry before turning on the cell. That is to say, they make sure the inlet and outlet temperatures are the same. That does not mean they do not momentarily turn off the flow while starting up the cell. If that is how they do it, the configuration could just as easily be a cell inside, with the water normally flowing around it. Not a torus. When the outside jacket is drained, there is an air gap between the copper and stainless steel cell. I think heat from the heater would reach the cell. Or, as Axil suggests, the outside heater could serve as a blanket while the inside heater does most of the work. The only problem arises when you suppose the water is flowing the whole time, because that would carry off the heat from the outside heater, and prevent it from heating the inside cell. - Jed
