AN IMPROVE- MENT IN BOILERS TO PREVENT CORROSION to be as
Year: 1884

page_text: .PROVISIONAL SPECIFICATION.
I, JOHN STARK, of Glasgow, in the County of Lanark, Scotland, Marine
Engineer, do hereby déclare the nature of the said invention for "AN IMPROVE-
MENT IN BOILERS TO PREVENT CORROSION to be as follows:-
:
"
My invention relates to iron boilers or steam generators, and it is designed to
obviate the corrosion or " pitting" of the surface exposed to the water, whether of
the boiler tubes, flues, or plates.
My invention consists essentially in the construction of a boiler, the inner
surfaces of which are partially or entirely coated with a thin layer of zinc, or
other suitable material which shall protect the iron, but is not of sufficient
thickness to interfere with the proper transmission of the heat of the furnace to the
contents of the boiler. This coating is effected by the known process of electro
deposition, or by dipping into or washing with molten metal, and this electro
deposition, dipping, or washing is conveniently, though not necessarily, done before
the building up of the boiler.
'
FELL & WILDING,
Agents for the Applicant.
COMPLETE SPECIFICATION.
I, JOHN STARK, of Glasgow, in the County of Lanark, Scotland, Marine
Engineer, do hereby declare the nature of my Invention for AN IMPROVEMENT
IN BOILERS TO PREVENT CORROSION" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My invention relates to iron boilers or steam generators, and it is designed to
obviate the corrosion or pitting of the surface exposed to the water, whether of
the boiler-tubes, flues, or plates.
My invention consists essentially in the construction of a boiler, the inner
surfaces of which are partially or entirely coated with a thin layer of zinc, or other
suitable material, which shall protect the iron, but is not of sufficient thickness to
interfere with the proper transmission of the heat of the furnace to the contents of
the boiler.

page_text: It is well known that in boilers in which a large number of small tubes are used,
for the transmission of the heated gases through the water, the said tubes are very
subject to pitting and corrosion, requiring constant repair, attention and replacement,
during the voyage of sea-going steamers. To avoid these drawbacks I provide
tubes, coated externally on the surface at which pitting takes place, with a thin
layer of zinc, conveniently produced by an electro-deposition or by dipping the
tube into, or by washing it with, molten metal, such as zinc This process I find
to completely protect the said tubes from corrosion, without at the same time
injuring the strength, or tenacity, of the material of the tubes. My improved
tubes, so coated, may be fitted into any multitubular boiler, or may be carried as a
reserve for replacement in case of accident.
As it is found also that the shell and flues of boilers, where in contact with the
water, are also liable to considerable corrosion and pitting, I may, as a protection
against such destruction of the plates, provide my improved boiler not only with
its small tubes covered by the protecting coating of zinc as above described, but
also provide a protective coating to the internal shell of the boiler, and to the
exterior surfaces of the flue, by electro-deposition, or by dipping into, or washing
with, a molten metal.
The coating of the various surfaces and tubes, by the protective metal, may be
carried out before the parts are brought together for construction as a boiler; or,
I may alternatively fill the boiler, after construction, with the solution of some
convenient salt of zinc, or of any other desirable metal, and may therefrom deposit,
by electrolytic action, a suitable protective surface upon the whole of the flue,
shell, and tubes, where in contact with the water.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1st The construction of a boiler with the surface of the boiler-tubes, flues, or
plates, where exposed to the water, covered by a protective coating of zinc, or other
suitable metal, deposited by electrolytic action, or other suitable process,
substantially as described.
2nd The combination with any known boiler shell and flues, of tubes, coated on
their exterior surface, where in contact with the water, with a protective coating
of zinc, or other suitable metal, deposited by electrolytic or other suitable process,
substantially as described.
Dated this 22nd day of October A.D. 1884.
FELL & WILDING,
Agents for the Applicant.