At 11:04 5/31/2000, Rico Sapolich wrote:
>Thinking about it later, I reasoned that if such a scheme were effective,
>then every power plant in my experience which used sea water in its coolant
>system would have used it.  All I can ever recall seeing were rather large
>consumable anodes mounted to their intake structures.

Active systems are used on (some) ships and other marine installations (and
rich pleasure yachts).  They work very well by impressing a current that
opposes and overpowers the galvanic current.  However, the current involved
is something like 100 ma per square meter of protected surface, and you
need electrodes all over the joint (dunno how close together).  You need
the bulk conductor provided by the seawater to make it work.  I'm sure it
would work fine on the intake gratings, but likely more trouble to set up
all the active stuff than to use zincs and eventually replace the
grating.  The power plant is unlikely to sink or have its propellor fall
off, after all <g>.

d
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"