A low frequency magnetic field (basically DC turned on and off) could help agitate the powder and dissipate hot spots, but at temperatures above 360°C curie temp of Nickel (that appears to be where the reactors operate according to DGT) static magnetic fields will have no effect on pure nickel.
We really haven't seen any indication that an applied magnetic field is necessary or useful to the reaction, The reaction appears to continue even after the resistive heating element (with it's associated magnetic field) is turned off. I calculate that for nickel particles of 4µm and the reasonable high density of high pressure hydrogen even in such a small reaction chamber the convective gas motion is capable of blowing nickel particles around - basically a slow and gentle geyser in the hotter centre of the chamber lifting particles up to then fall down the cooler walls, thus slowly mixing and agitating the powder. On 24 January 2012 19:40, David Roberson <[email protected]> wrote: > It is not clear at all how DGT is initializing the reaction. Maybe the > hot chemical that assists the startup is only used to back up the main > electrical heating element. This may be a way to heat the chemical over > a relatively long time period without too much power and then having it > release its heat quickly into the inner cube at the same time the > electrical heating is available. It would seem possible to effectively > multiply the peak heating requirement by a factor of 3 or so in this manner. > > I agree that they must have a well designed and functioning control unit > to prevent meltdown. How nice it would be to have data to review as we > give consideration to these ideas! Guess we might have to wait before we > get our probes onto a final device. > > Do you think that DGT would have determined a safe temperature to preheat > the core to before having to worry about thermal runaway? Their testing > should have allowed them to see that there is no danger of runaway when the > core is at, as example, 300 C. So any preheating liquid at or below that > temperature could flood the device with no danger. Only after that > temperature has been achieved would the control system and electrical > heater have to kick in and work well. > > I have long suspected that the RFG is mainly to confuse others and > misdirect their efforts. DGT does not suggest that they have one in their > design. The magnetically transparent steel might allow static fields to > enter freely, but if it is a conductor of reasonable performance, RF fields > would not enter. > > Their working with "nudist" reactors is confusing. I wonder if the > reactor for this test is only being loaded with a small Hydrogen charge. > How would they possibly get the heat out of a normally functioning device > with no coolant flow? I suspect that they are interested in just proving > that LENR is real but not operating at the required levels. I would expect > that the P(T) curve would be modified greatly by the charge level. As we > know, no hydrogen means no power so a small amount must result in a modest > power gain. I would rather see a fully functioning unit in operation and > being measured. > > We speak of the maximum operating temperature of the coolant as being > below the specified output temperature. I suspect that we just are not > aware of the type of coolant that they are using. Now, since they claim > that they operate at 600 C or more under normal conditions, then why could > they not use some of the coolant as the initial chemically assisted heating > material? This would be in line with my suspicion that the pumps are > stopped while the device is brought up to the desired range. > > One thing that I have wondered about for a while is the effects of low > frequency magnetic fields. I assume that the nickel powder is attracted to > a magnet at room temperature. Would a slowly changing field cause the > material to be continually mixed up and agitated? Perhaps this motion > would keep the material alive. A low frequency magnetic field could > penetrate a modest conductor. > > Dave > > > -----Original Message----- > From: Alain Sepeda <[email protected]> > To: vortex-l <[email protected]> > Sent: Tue, Jan 24, 2012 12:43 pm > Subject: Re: [Vo]:Rossi's Best Chance > > > Being fast to start and avoiding meltdown mean that they have a very good, > nearly optimal control. > Maybe part of the secret is classic control theory, helping to design the > optimal retro-action, once you know the core thermal parameters... > > but being also able to work without cooling, with "nudist" reactors under > the sky, mean they don't need the coolant to survive... > something is stabilizing the core, or at least helping/damping the core to > be stabilized from far by a very good temp->power loop (maybe a good PID > predictor). > > One idea would be that they use very fast induction heating, but they say > NO RFG... maybe induction is not RFG for them (true in a way). > this might explain why they use (as someone explain here) a magnetically > transparent steel. > the stability of the core might be about the powder behavior at high > temperature, relative to induction... (why not curie point? 627 C?) > but in their spec they talk about resistors, not induction coils... > they talk about a chemically assisted preheating... undisclosed. > pre-heat 6 seconds... max op temp 1050C... > > however coolant oil is limited to 350C, and 430 for molten salts... not > the 600C we see as limit for the tests... > > whatever they did, it is smart job... either a tricky intrinsic feedback > (like lead-bismuth nuke do), or optimal control, after good modelization. > > > 2012/1/24 David Roberson <[email protected]> > >> The design of the DGT device allows them to lower if not stop the coolant >> flow into the heated core unit. The heating of the core can then be much >> faster and also require less net energy than Rossi's configuration. I >> would expect that both designs would need approximately the same >> temperature for efficient output. This is just my opinion, but I think the >> DGT design is more ideal. >> >> Dave >> > >
