On Thu, Jul 21, 2011 at 1:42 PM, Abd ul-Rahman Lomax <[email protected]>wrote:
> No, increased pressure is caused by the pump (I have little idea how much > it will cause, but my guess is that this isn't enough to raise the pressure > to atmospheric), and by steam pressure from boiling. Even a little boiled > water will significantly raise the pressure. > > This leads to a possible analysis. [...] from an on-line calculator for > steam flow through an orifice. > > I also found an on-line calculator that calculates the pressure difference to produce a given flow of steam through conduits of given diameter and so on. For steam (unlike water) the pressure difference turns out to be most sensitive to the number and geometry of the various fittings, like expanders, reducers, and elbows, all of which are present, and give rise to an overall K-factor. But there is no category for 2-phase flow, even if we knew the ratio, and so even with detailed knowledge of the geometry, I think the only purpose such an analysis serves is to make a slightly elevated boiling point plausible. Any attempt to extract enthalpy information from such slight elevations, is trying to make a silk purse out of a sow's ear, at least without careful calibrations. And why bother? Rossi could either decrease the flow rate so the steam was dry and well above the boiling point (by tens of degrees), or increase the flow rate to prevent any phase change, and these speculations would be unnecessary.
