On Tue, Jul 19, 2011 at 7:12 PM, Abd ul-Rahman Lomax <a...@lomaxdesign.com>wrote:
> > Sure, if you sufficiently obstruct the flow, you could lift styrofoam > easily. I was referring to a *piece* of styrofoam, presumably small. And the > question was about bouyancy, not about flow. You can support a whole person > with air flow, all you have to do is get the air flow running at roughly 90 > mph, i.e., "terminal velocity." So? Well, he did say float it over a pot of boiling water, in which case the steam flows upward. He didn't mention buoyancy, and "floating" can be used to describe a person supported with air flow. In fact, the ping pong ball demo is usually called the "floating ping pong ball". "Floating" is routinely used to describe astronauts floating weightless, which has nothing to do with buoyancy. But I have no idea of the relevance of any of this to the ecat. >> You've said this several times. But you have not supported it. Why can't >> the steam be wet; >> > > The steam is wet. that's why the question is a red herring! It's wet, but > *probably* not "very wet," i.e., enough to have a major impact on energy > calculations. What I meant was, why shouldn't it be very wet? > The E-cat starts with water running through, the entire pumped flow is > running out the hose. It's turned on and the water starts to heat. What > happens? First of all, what's happening before boiling starts? Here is my > thinking: water is at the level of the opening to the outlet hose, so it is > spilling into the hose. There is air above the water, initially. The opening > to the hose never fills entirely with water. Rather water runs out in a > trickle matching the pump rate, runs down into the hose, and accumulates > there until it reaches the drain level, and then it runs out the drain. If > siphoning doesn't occur, this will be, steady state, water running down into > the hose, and the same rate of water flowing out the drain. There is air > space remaining, all the way down into the hose to the level of the drain. > Below that there is water. > > When steam generation starts, pressure will develop in the E-cat and the > hose, steam will start to flow out above the water. Stop there. The steam is formed in the ecat. It has to get through a small diameter pipe and then the chimney which is (initially) filled with water. The steam takes up much more volume than the water. As it passes through the water, there will be violent churning. If the steam occupies more volume than the water, you no longer have a chimney filled with water. If the steam occupies 10 or 100 times the volume, then the picture of a chimney filled with water and the water trickling into the hose just doesn't fit. > Water will continue to flow out the drain as before, reduced in volume by > whatever water has boiled. The water vapor from boiling will be ordinary > steam. If it's frothy, that's from turbulence inside. I rather doubt it's > frothy, as such. Rather, this is steam bubbling up from the cooling chamber > through water to the level of the outlet hose opening. It then escapes above > the flowing liquid water. The water level will drop below the outlet opening > only if the input flow is below the steam generation rate. It's this bubbling that bothers me. Bubbling somehow refers to the gas rising, governed by buoyancy. But that simply isn't fast enough to get the steam out in time. The volume of steam is probably more than 10 times that of the water. Depending on how much faster it moves than the water, it will in fact occupy a much larger fraction of the chimney volume than the water. When the gas volume exceeds the liquid volume by an appreciable amount, I don't think you can call that bubbling any more. The bubbles will merge leaving liquid bubbles (droplets) within the mainly gaseous flow, as well as some liquid along the walls. I think this sort of volume of steam will basically push everything in front of it through as a mist or aside against the walls, and the turbulence will form some kind of very wet steam. The literature on 2-phase flow is pretty clear on what you get when you force two phases through a conduit of known diameter. The problem is we don't know the conduit diameter, or if the chimney has a nozzle, or a coil of small diameter tube, which will produce a mist. There is a real benefit to Rossi in producing entrained mist in the ecat, because it will be easily mistaken for steam, and it will not be collected as a liquid if anyone happens to examine the output. The steam is "wet" because steam generated from boiling like this is > practically always wet unless special devices are used to separate the water > from the vapor. So there are three outflows: liquid water, as a mass of > water, flowing as water, water vapor, and entrained liquid water as mist. > Right, but in ordinary boiling, the entrained mist comes from what really is bubbles formed near the element rising due to buoyancy and breaking at the surface in a volume of water much larger than the volume of steam. This is gentle boiling. The ecat is different. It's a much more confined volume, and the steam volume exceeds the liquid volume, and both are forced through by a pump. This is how very wet steam is produced; forced 2-phase flow through a conduit. Not by boiling a large reservoir of water in a boiler. They are simply not the same. > All of these are at the same temperature as they leave the E-Cat. That's > the characteristic temperature of boiling water, at the pressure present > inside. > > At any point here, once boiling is established, open the steam valve at the > top of the chimney, and what do you see? You see steam, quite possibly > "live" as to what it looks like. (That is, very low mist content, so it's > quite invisible until it cools from air contact.) > Unfortunately, we have very little to go on for this. It was "dry" by a Swedish visual inspection. I suspect it would have a pretty high mist content, but would move fast enough near the opening as to be nearly invisible. But we can only speculate. > > If you drain the hose and look at the end, held up, you will see mist and > maybe some live steam coming out, depending on the cooling that's taking > place in the host itself. It will be weaker steam than you'd see at the > chimney vent, that's practically certain, so the arguments based on steam > quantity at the end of the hose are also, at least to a degree, red herrings > as well. Jed wants to look at the steam, sparging it close to the E-Cat, > because he knows that this is far cleaner, because the cooling in the hose > could mask a lot of heat! > I seriously doubt that very much heat is lost in the hose. A few hundred watts maybe. In the 5 kW experiment that would not be significant. But, I do think that some separation of liquid and gas would happen along the hose, giving rise to a less misty steam and some actual water flow, which explains why Lewan collected half the input as a liquid. But again, we have not been given a good look or analysis at what comes out. > > Because Lewan noted that the volume of water in the bucket did not match > the inflow, we might infer that there is some vaporized water. The problem > is determining how much, and Lewan did not report quantitative measurements. > I remember reading half somewhere. But again, this measurement means nothing because I maintain the steam that escapes could easily have carried much of the rest of the liquid into the air as a mist. > > Nobody seems to have realized and addressed, in observing the demos, the > possibility of overflow water. > I think Rossi's goal was not to have any real flow at all; that all the liquid would be carried as a mist that could be mistaken as steam. And I think that is entirely possible to set up. So to me, the absence of liquid flow would not be significantly better evidence of excess heat than a flow + steam. There is plenty of literature on producing steam with more than 90% liquid mist by mass, and the ecat could certainly be designed to produce it. And as I said there is every reason for Rossi to do that. Note: what I've come up with doesn't explain all the heat, it could simply > explain some major part of it. With respect, and notwithstanding disagreements on details of the phase separation, you're a little late to the party explaining the lion's share of Rossi's claimed heat. "Come up with" is a little presumptuous. A lot of people on a lot of forums were questioning the degree of vaporization almost from the beginning. Once you've accounted for a factor of 7 or so by assuming only a small fraction of the water is vaporized, any additional claim of excess can be plausibly understood by a few small misrepresentations in flow rate or power, evidence for both of which is in abundant supply. > It would be practically trivial to determine the matter. But about the time > that the community gets wise to this overflow issue, I wouldn't call it an overflow issue, but a lot of people were wise to only a small fraction of the water being vaporized a long time ago. That's why the story has not gone beyond a few second rate news sites. It took a little longer for the usual supporters like Krivit to get wise to it, and that irks Rossi because he needs the support of believers.
