The wonderful physics of heat exchangers

  • Bruce H - one of the things that amazes me around that episode is R's ability to think and move so quickly. Fulvs called him to let him know that inspectors were in the building and needed to see everything. R shows up and starts taking pictures with some kind of plan in mind. Was he thinking 2 to 3 steps ahead on how to leverage that situation and create more deception/confusion? Something tells me that he was and that he has the skill / nerve to attempt to pull that off. Pace teed that one up in the deposition and tabled it until judge and jury after R spun up the picture conspiracy whopper in depo. Metadata doesn't lie.

  • THH - another question comes to mind on decibel levels. IF the magnificent creation in Doral was turning out such a lovely steam product, it seems that the noise level from that steam moving around the system would be deafening. (supersonic inside certain piping according to some calculations). I think that everyone would have needed hearing protection to be near that thing if such output would have been actually occurring. May I ask for your thoughts on that (with the stethoscope monitoring system of mind of course)?

  • I have worked around superheated steam systems quite a lot. They don't make a lot of noise.


    ETA- The speed of sound in steam at 14.7 psia and 300 F is 1653.92 ft/sec. Mental arithmetic makes that something over 1000mph. Very unlikely.

  • THH - another question comes to mind on decibel levels. IF the magnificent creation in Doral was turning out such a lovely steam product, it seems that the noise level from that steam moving around the system would be deafening. (supersonic inside certain piping according to some calculations). I think that everyone would have needed hearing protection to be near that thing if such output would have been actually occurring. May I ask for your thoughts on that (with the stethoscope monitoring system of mind of course)?


    Well I guess it depends on how much of the steam noise inside the pipes leaks out., but metal pipes do not provide much sound insulation.


    LN = 10 + 50 log (v) + 10 log (A)


    v and A are related by v = F / A where F = 36000 m^3/day = 0.4M^3/s


    So Ln = 10 +50log F - 50 log A +10logA = -10 -40logA


    For A = 20mm diameter = 3*0.02^2= 1.2E-3,

    We get -10 -40*-3 = 110dB


    Live rock music, or a riveting machine


    It goes up as the pipe inner diameter gets smaller.

  • The steam speed in 20mm diameter pipe is pretty close to teh speed of sound:

    470m/s (speed of sound in steam at barg=1)

    330m/s speed of Rossi-pretend steam in 20mm ID tubing.


    So if any of the tubing before much of the 1MW power has been dissipated is 10mm ID we have steam speed > speed of sound which i'd guess has consequences though I've no idea what!

  • The only disagreement I have with your logic is that of the prejudice on VC's.


    I have no inherent prejudice against VC's , as I actually said, they are 'good and bad'. A necessary evil in a de-regulated economy. When I say they are 'not my kind of people' I meant that I tend to prefer the company of artists, writers, and creative academics. Those are the people I prefer socialise with, in general I find financiers to be a 'dry lunch'.

  • Alan - you've been around well-designed super-heated steam systems that were engineered for the steam dynamics including erosion, corrosion, sound and, dare I say, hydrogen embrittlement in certain instances. You also never saw a system

    with rusty effluent - the steam plan engineers would have shut everything down and fixed that.


    THH - so we have a high db environment on the "steam side" as well. Wonder how often those valves and elbows needed maintenance?


    AhiAhi - I love your work ethic on behalf of "the story". Your headset images are from Ferrara and were protection from the 500kw generator that was sitting beside R's shipping container. That sucker apparently put out a lot

    heat and noise when it was running. The only hearing device picture I can find from Doral is a stethoscope - must have been a very special specification kind of stethoscope.

  • You also never saw a system

    with rusty effluent - the steam plan engineers would have shut everything down and fixed that.


    I never saw a superheated steam system running on untreated town water either. That's where the rust comes from in the main - oxygenated water at the wrong pH plus bemetallic corrosion caused by unwise mixing of metal types in the system as a whole. I always said that Rossi needed a serious steam engineer.