The morning call. [volume] (San Francisco [Calif.]) 1878-1895, 1890-11-21
TO DISTILL WATER AT SEA.


Success of a New Device for the Use of
Ships.
Since the almost universal adoption OF
high-presSure steam, rapid combustion of
fuel, and consequent rapid evaporation of
water. the greatest trouble Of the marine
engineer has been how to keep his boilers
clean. The use of fresh water is an abso-
luto necessity; the use of salt water for
few hours would cripple most modern
boilers for life. OF course ships start ON
a voyage with their boilers full Of fresh
water, which. after doing duty as steam in
the engine. is condensed and returned to the
boiler again. There is, however, always
considerable amount Of waste that has to be
made up from somewhere. The newest
ships of the royal navy are fitted with tanks
in their double bottoms to hold a reserve of
fresh water, which also serves as ballast,
but this somewhat crude device is obviously
not capable Of general application.
Various kinds OF apparatus for converting
sea water into fresh by distillation have
consequently been employed, but all have
been more or less unsatisfactory in the
working. Though some of them are able to
produce a considerable volume of water,
they all alike suffer from the same defect
that, while by the use OF fresh water the
deposit of scale in the boiler is prevented,
the distlllers themselves rapidly become
scaled up, their cooperative power becomes
seriously diminished, their tubes leak, and,
The water produced being no longer per-
fectly fresh. they require constant care and
frequent cleaning, so that, in fact, the
trouble is only removed from the boilers 10
the distilling apparatus.
An evaporat0r on new principle, like
many other good things of American origin,
has recently made its appearance, called,
from the name of its inventor, the Yaryan.
The one feature that distinguishes this
apparatus from all those hitherto in use is
that, whereas in them the sea water to be
distilled is invariably at rest in the Yaryan
it is in state OF rapid motion. 1t is claimed
that, owing 10 the feed being introduced in
the form Of thin cloud OF spray, the
evaporation in the Yaryan is much more
quickly effected and the relative evapOra-
tive power of each pound of steam used Is
far higher than in other machines. For the
same output of distilled water, the dimen-
sions and weight of the Yaryan are much
below those of previous evaporators.
An important point in the Yaryan is that,
even in the largest sizes, there are never
more than few pounds weight of water IN
the machine at any one time. This effects
great saving in total weight over other ma
chimes. A Yaryan, for instance, capable of
delivering fifty tons of distilled water per
day is cylinder only feet long and 81
feet in diameter. Owing TO the condition OF
rapid movement through the machine Of
the water under evaporation, scaling of
the machine itself Is almost entirely absent.
At present only one ship has been fitted
with the new distillers, but the results have
been so entirely and remarkably successful
that there is no doubt that the invention
will be largely adopted in the future. The
ship in which the Iaryan has been used is
tie Prudence of Cardiff, a new screw steam
er of 23l9 tons and 1200 horsepower, trading
between America and France.
Mr.. Thomas SODer, manager for MesSrs
Humphreys, Tenant ~ Co., the wel-knnwE
marine-engine builders at Deptford, and late
of the EngIneer-in-Chiefs Department at
the Admiralty, reports that on the 18th inst.
he visited the Prudence at Rouen. The
machine had been worked during two COM
plete voyages to and from America, that Is.
for about seventy days under steam. and
during this time had not been cleaned in
any way. The condition of its interior was
very satisfactory, the tubes only being
coated with thin scale which nowhere ex-
ceeded one thirty-second of an inch in thick
ness quite insufficient to cause any appreci-
able reduction OF the efficiency of the appa-
ratus. The water in the boilers, which
were perfectly clean, had been taken in at
New Orleans and was practically fresh, and
to keep it so the Yaryan had only been
worked from four to five hours each day.
The engineers stated that no special care or
attention was required either in starting or
in working the machine, which is all but
automatic, and gave no trouble whatever.
If, as there seems little reason to doubt,
such results as these can be obtained always,
great load will be taken off the backs of
chief engineers, both in the royal navy and
the mercantile marine-I, OndOn Times.