On Sunday September 08 1996, Alec Cameron of (3:712/517.12) wrote to Chris 
Harper:
 AC>> In a boiler pressure and temp are usually bracketted. Utility boilers
 AC>> run at about 2400 psi and 1100 deg F.
 CH>> I don't intend on going anywhere near those figures! At least not
 CH>> anywhere in the near future!
 AC> I quoted those figures not for your approval! but to indicate the
 AC> aggressive conditions inside the steel boiler drums and water tubes.
Well, I certainly don't approve! ;-) I'm sure I can get some decent power 
generation at much lower figures. Cooling steam from 1100 degrees F. would 
take much to long for me, and I can see why impurities would accumulate. The 
high temp acts as a catalyst, allowing the steam to dissolve the metals in 
the system, and create those ion composites that are so corrosive.
 AC> The severe conditions I remember, were with coastal generating stations
 AC> which used ocean or river water for condenser cooling. The condenser
 AC> running at negative pressure [vacuum] there would sometimes be water
 AC> ingress due to leaks in the condenser structure. Counter measures 
included
 AC> dumping truckloads of sawdust into the water canal, the sawdust plugging
 AC> the condenser leaks then swelling so improving the temporary "repair".
I'll have to remember that, as I will be running at much lower temps, and the 
condensation will thus be much faster, and create a vacume in my condensor 
tubes. I will definately have to take this into account in my design. I had 
thought of using garden hose for condensor tubes once the steam was cooler 
than 250 F., but with a vacume there, they would collapse and expand 
repeatedly, and thus wear out. Now I will have to use a pressure equalization 
chamber to allow for expansion and contraction, if I want to keep it a 
"closed" system.
Thanks for pointing this out! I could have lost some money with hoses wearing 
out prematurely and needlessly, as well. With them being buried, I would have 
never seen them collapsing, and they'd have started leaking quite soon.
Thanks,
       Chris
--- GoldED 2.40+
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