Thanks again.  It appears like DGT actually had 20 plus kilowatts of power 
being delivered according to the information thus far.  Does anyone recall 
seeing evidence of a magic trick of some type regarding the output vapor?


One observation I recall from the video was that they tended to keep the camera 
focused upon the multiple temperature readings most of the time and spent 
little time on the output temperature and flow rate indication.  This may have 
been due to them having to closely monitor the temperatures, but it seemed 
excessive.  At the time, I had the feeling that they did not want those 
indications followed closely by the audience.


According to the data presented by Alan, it appears that the input flow rate 
should not have been materially modified by the reverse steam pressure since 
that would not have been significant when compared to the grid input pressure.


Has anyone seen the published data collected during the demonstration?


Dave



-----Original Message-----
From: Alan Fletcher <[email protected]>
To: vortex-l <[email protected]>
Sent: Fri, Aug 16, 2013 8:29 pm
Subject: Re: [Vo]:DGT Test Questions


> From: "David Roberson" <[email protected]>
> Sent: Friday, August 16, 2013 4:33:03 PM

> Thanks for the good information. When the drop was calculated as .5
> bars, was that assuming dry steam at 165 C? 

I think the peak was 165C -- I may have used 14C in some of my calculations

> Also, if the temperature  measures 165 C at the output test point, does that 
automatically
> result in dry superheated steam? 

Depends on the pressure. Assuming 22kW, will be dry, superheated if it's below 
about 3.5 bar

> I ask this question because there
> most likely will exist an initial boiling point somewhere within the
> device enclosure that should be a bit higher than 100 C. The initial
> boiling vapor would transport some water drops along the pipe as it
> moves toward the output. Extra heat would be gained as the wet vapor
> travels outward which would vaporize additional water. At some point
> in space all of the liquid is vaporized so that from that point
> forward we have dry steam.

Yes, you will have the various modes water, bubbles, voids, drops, dry steam at 
various points in the heater coil.

The progression I described is what you see as the whole system heats up. Once 
it's stable, then you'll have these affects in the heater coil, but you wont 
see 
them at the outlet.

Gravity will tend to hold the water at the bottom of the coils, so you might 
even hear it "percolating" in the earlier, inner coils. 

> I find it difficult to believe that the temperature measurement at
> the output test meter would be able to read 165 C if water drops
> could exist at that point. Of course, this assumption would only be
> true if the pressure at the output test point were near atmospheric.
> The .5 bar estimate is small enough for this to be true. How high is
> your confidence level that the pressure remains this low?

Not 100% -- I used a table similar to the metric one here : 
http://www.engineeringtoolbox.com/steam-pipe-pressure-drop-d_1129.html

The flow rate was 0.5 l/min, total power 22kW (assuming no cheating and 
saturated steam)

The pressure drop in  a 20mm ID tube at 30 kg/hour in a 30m tube is about 0.2
But there's a scaling factor --  MUL * 5 for 0.5 bar, DIV 1/3 for a 10m tube

   Hmmm .. is the steam pressure standard (1 atm = 1bar) or gauge (1 atm = 0 
bar 
)

0.2 * 5 / 3 = 0.3 bar pressure drop

It's sort of recursive ... but I'd guess in the range of 0.5 to 1.0 drop -- 
since the end of the tube is atmospheric, the temperature in the coil would be 
0.5 gauge, 1.5 standard.

> Could you direct us to a source that calculates the pressure drop in
> copper pipes expected with steam flow?

See above. The corrections for steam in a rough pipe isn't as great as the 
correction for water.

Plugging those into my calculator gives :

<a 
href="http://lenr.qumbu.com/ecatcalc.php?plot=Plot&ever=c&efzx0=0&efzy0=0&efzx9=9&efzy9=9&esl=1&epbr=1&enm=Defkalion+steam+0.5l%2Fmin+22kw+1.5+bars&edh=0&edm=1&eds=0&eif=0.5&eip=2&ecp=0&eop=22&eoxr=1&et0=25.62&ep0=1&et1=25.62&ep2=1.5&er2=2";
 
target="_blank">Defkalion steam 0.5l/min 22kw 1.5 bars</a>

BUT : if the outlet pipe isn't insulated all the way then there'll be a 
temperature drop too, resulting in a different pressure gradient.

You really need a skilled steam engineer here !


 

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