Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1904-11-11
SCALE IN STEAM BOILERS.
Consideration Of Some Of the Benefits
Derivable from It.

Is scale in steam boilers a benefit or
All iniurN? That it is generally as
su,ned to be the latter We are well
aware and there is no doubt. Of
course. that the scale which forms in
boilers using hard water is very
great nuisance and one which involves
large expense III caring for II. But
suppose. for the sake of argument,
that boilers were supplied with water
absolutely free from mineral matter.
let US say with rain water or distilled
water. Would not the troubles that
would be experienced far exceed those
that are now caused by scale? To
put the question in another form, Is
not the scale which forms in a steam
boiler fed with pure water really a
benefit in protecting the interior o: the
boiler from the rapid corrosion VIII n
would otherwise take place
In Il paper by Mr.. NJ. f.. Wells, chief
boiler inspector of the Burlington and
Missouri River railroad, the fact is
pointed out that boiler tubes piled out
doors and exposed to the weather rust
out faster than tubes inside n boiler.
The statement is made by Mr.. Wells
that perfectly pure water is the most
and, finally, he expresses the opinion
that mature has provided incrustinS
matter in water that the inside of the
sheets of boilers may be coated with a
layer Of it, ana thus De protected from
oxidation
50 fan as we are aware. this idea
has never before been set forth in
technical literature. We do not
mean by this that the fact that boiler
scalr protects from gorrOSion has not
Icen noted and nut on record. but
that the general importance OF scale III
b,.l.-rS - Il protection and preserva-
tive has never been rccoGniz<l by any
OF tioS,. vino have STUFFED steam boiler
c"r-tru, ti"n and written treatists upon
it.
Very likely many engineers Will ques-
ton the SnundncsS of Mr. Wells state
m"ni aL"rr quoted bat There seems to
ue t. h.. much evidence in its support.
We know that boiler shells (Which have
been ia service for wears when protec-
ted from external cOrroSiin often show
scarcely any Ginnu,iDn in thickness,
whereas if the sL:he material We're
immersed in a liver or pond it would be
rustcd very rapidly. Again, practical
exprritnc" has sh0"n that boilers in
which rain water alone is used have
givrI trouble from internal cOrrosion
and il has been Frequently astribed to
acid gases absorbed l.y the water from
the air. I;ut may not The true eXpla-
nation be that no scale is deposited by
such water to protect the metal sur
faces?
h.. of hat
practical benefit would be a general
knowledge Of the prott tive power of
scale. One benefit might be the more
intelligent care of boilers Many large
power plants are now using the same
feed water over and over again by the
use of SUI face condensers or cooling
towers. There will usually be sufficient
makeup water used in such plants to |
protect the boiler surfaces. vet there |
may be cases where internal corroson |
is going on unknown to those il. charge |
of the plant
Another field that has never been eX-
plotted Is the possible use of scale to |
protect other metal surfaces than |
boilers from corroSion. Any one who !
has tried to remove calcium Sulphate
scale from Boiler tiuas or STAYS knows ,
with what tenacity it will often ad-
here 1t might be practicable to treat /
various metal articles, such as fence
posts or water mains, by imnersiug
them in closed tank containing A
saturated solution of calcium sulnhatc
ana then partially eVaporating the |
solution. Certainly The demand for
better and more effective methods of
protecting iron surfaces. from cnrrosioo
is great enough TO encourage eXperi-
mpntS in this field