Abd, you are correct of course. It was 3am when I wrote that post in a vain effort to persuade myself that Rossi demonstrations are too ambiguous arrive at any sort of conclusion. However, unlike you, I do think the evidence is sufficient to make a judgement about the veracity of Rossi claims. After all the intent of the demonstrations is to *persuade*. On the other hand, you seem to treat the demonstrations as an unfinished game of how-does-this-black-box-work-? as if Rossi intentions were irrelevant. Harry
From: Abd ul-Rahman Lomax <a...@lomaxdesign.com> >To: Harry Veeder <hlvee...@yahoo.com>; "vortex-l@eskimo.com" ><vortex-l@eskimo.com> >Sent: Thursday, July 14, 2011 11:30:55 AM >Subject: [Vo]:Estimated range of possible power shown by 2 ml/second water >flow in a Rossi-type demonstration > >At 04:01 AM 7/13/2011, Harry Veeder wrote: >> >> If we apply the logic of the "block box" to the eCat then it is possible to argue it is a hoax even if the output is only dry steam. >> >> This is based on the assumption that it is theoretically possible to use a >> 600-700 watt resistance heater to transform a water flow of 7 liters/hours >> (2ml/second) into dry steam if the amount of time the water spends next to >> the resistance heater is maximised. eg. if the water tube is narrow and >> forms a tight spiral around the resistance heater. > >After all the discussion, it's frustrating to read a post like this. The >energy required to boil the water does not depend on how long the water is >"next to the resistance heater." Heat transfer efficiency is an issue, but not >in this way. The heat from the heater must go somewhere. It goes into heating >the device, into heating the water, and, ultimately, it is either dissipated >directly to the air or into the water. > >Generally, an upper limit on power is set by the assumption that all the >heater power is transferred to water heating and boiling. > >Taking figures from Kullander and Essen, to take water from 18 C to 100 C >requires 95 Wh/kg. To do that and boil it requires requires 725 Wh/kg. This >value is independent of the time it takes. > >If the flow is 2 ml/sec, this is 7.2 kg/h. Thus the continuous power >dissipation required to fully vaporize that flow rate is 5.22 kW. > >The continuous power dissipation required to just take the water to 100 C, >however, is only 684 W. > >What we have as demonstration reports is that the water does reach 100 C., >though it is possible that not all the water reaches that temperature (there >is a possible fraud mode whereby there is a direct bypass of some water to the >outlet hose; this would require special design and effort, which is why I call >this a fraud mode rather than simply a possible error). > >From the reports, the chimney temperature in the E-Cat does not exceed >slightly more than 100 C. If the water all boiled away, the steam temperature would probably rise above boiling more significantly. > >If we assume that the flow rate is correct, then, we have a range of possible >heating power between 684 W and 5.22 kW. If we assume 700 W input power, the >generated power in the E-Cat, is between approximately zero and 4.5 kW. To >narrow this down would require knowing the percentage of water that is >vaporized, and this is exactly what we do not know. > >In many discussions of this, it was assumed that the only issue was "steam >quality." If we were to assume very wet steam, say 20% by weight, we would >then be able to infer excess heat, assuming complete boiling (only merely >"wet"), of about 3.6 kW. This is why some think steam quality is a red herring. > >If there is no excess heat, under these conditions, there might be a small >level of boiling, it's marginal and would depend on the exact power and the >accuracy of the flow rate. If there is some boiling, the water and steam will be exiting the E-Cat at 100 C., as observed. However, at minimum boiling, 2 ml/sec of water would be flowing out through the hose to the drain. That water would be at the boiling point, it would be "steamy," i.e., mist would rise from it, plus any actual steam would create some visible steam flow. > >Would water flow be visible from the hose? In the Krivit video, Rossi holds up >the hose to drain it before pulling the end from the drain. If the hose is 16 >mm inside diameter, the hose capacity is 5 g/cm, or 500 grams per meter. To >fill a meter of hose would then require 250 seconds. Rossi empties more than a >meter of hose. There is plenty of time to show the end of the hose with no >visible water flow and some steam and/or mist exiting. > >We do not know how much water is unvaporized, no evidence is visible or >asserted, only the conclusion of complete vaporization is asserted by Rossi and some observers. > >Some have commented, including myself, that the design of the E-Cat leads to a >conclusion that it would be designed to "leak" unvaporized water, i.e., the >flow rate would be set such that the water would not entirely boil away, >because this would lead to reduced control of heat. Because of the technical >difficulty of attempting to set generated heat to *exactly* the level to cause >boiloff with a fixed flow rate, and because heating above boiling is not >observed, we can assume some (possibly small) level of overflow, runoff. > >In the Kullander and Essen report, >http://www.scribd.com/doc/58271737/Kullander-Essen-E-CAT-Report, they appear >to assume that input power is 300 W, based on seeing that power rating on the >label of the resistance heater, plus an indication of total input power of 330 >W, based on current of 1.5 A at turn-on. They do not report any later >observation or monitoring of input power. It is possible that input power was >later increased, particularly if the resistance heater was rated 300 W at 115 >V. I would expect the heater, water-cooled, to be able to handle the increased >power. > >(Rossi did his ad-hoc calculation of power using an obsolete figure of 220 V, >thus his power input estimate is low by about 5%. Kullander and Essen make the >same mistake.) > > >
