IMPROVEMENTS IN APPLYING ZINC FOR PREVENTING CORROSION IN STEAM BOILERS
Year: 1881

page_text: LETTERS PATENT to James Ballantyne Hannay, of Glasgow, in the County of
Lanark, North Britain, Chemist, for an Invention of "IMPROVEMENTS IN
APPLYING ZINC FOR PREVENTING CORROSION IN STEAM BOILERS."
PROVISIONAL SPECIFICATION left by the said James Ballantyne Hannay at
the Office of the Commissioners of Patents on the 11th June 1881.
JAMES BALLANTYNE HANNAY, of Glasgow, in the County of Lanark, North
Britain, Chemist. "IMPROVEMENTS IN APPLYING ZINC FOR PREVENTING
CORROSION IN STEAM BOILERS."
This Invention relates to the prevention of corrosion in steam boilers, and
consists in applying zinc for that purpose in an improved manner, the object being
to obtain a more efficient and reliable anti-corrosive action than heretoforo without
wasto of zinc.
When zinc is used in steam boilers as an anti-corrosive agent it becomes itself
corroded through its mass, and when employed in the form of plates or other
comparatively thin extended form, it rapidly disintegrates, and portions become
detached from the main body. It is believed that the maintenance of a proper
and sufficient metallic connection between the zinc and the shell or other part of
the boiler is essential, or, at any rate, of great importance for the obtainineut of
the desired anti-corrosive or protective action; and to secure this result the zinc
is by this Invention applied in blocks or masses which are of a spherical, or
spheroidal, or polyhedral, or cubical form, or other form having but amall
difference of thickness in different directions, preference being given to the simple
spherical form. Each sphere or block is by preference three inches or more in
diameter, and has a wire metallically united to it so as to extend to or beyond its
centre, the union being effected by casting the block upon the wire, or in some
other sufficient manner. The wire, which may be of copper or of other suitable
metal or alloy which is a good conductor of electricity, has its other end attached
by soldering, or brazing, or other equivalent means to the shell, or tubes, or other
part of the boiler which it is wished to protect from corrosion. The spheres or
blocks are placed in the water in the boiler in any convenient situation, and are
suspended or supported in any convenient way, but by preference not by means
of the connecting wires.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Ballantyne Hannay in the Great Seal Patent Office on the
8th December 1881.
JAMES BALLANTYNE HANNAY, of Glasgow, in the County of Lanark, North
Britain, Chemist. "IMPROVEMENTS IN APPLYING ZINC FOR PREVENTING
CORROSION IN STEAM BOILERS."
My said Invention relates to the prevention of corrosion in steam boilers, and
consists in applying zinc for that purpose in an improved manner, the object being
to obtain a more efficient and reliable anti-corrosive action than heretofore without
waste of zinc.
When zinc is used in steam boilers as an anti-corrosive agent it becomes itself
corroded through its mass, and when employed in the form of plates or other
comparatively thin extended form, it rapidly disintegrates, and portions become
detached from the main body. I believe that the maintenance of a proper and
sufficient metallic connection between the zinc and the shell or other part of the
boiler is essential, or, at any rate, of great importance for the obtainment of the
desired anti-corrosive or protective action; and to secure this result the zinc is by
my Invention applied in blocks or masses which are of a spherical, or spheroidal,
or polyhedral, or cubical form, or other form having but small difference of
thickness in different directions, preference being given to the simple spherical
form. Each sphere or block is by preference three inches or more in diameter, and
has a wire metallically united to it so as to extend to or beyond its centre, the
union being effected by casting the block upon the wire, or in some other sufficient
manner. The wire, which may be of copper or of other suitable metal or alloy
which is a good conductor of electricity, has its other end attached by soldering, or
brazing, or other equivalent means to the shell, or tubes, or other part of the boiler
which it is wished to protect from corrosion. The spheres or blocks are placed
in the water in the boiler in any convenient situation, and are suspended or
supported in any convenient way, but by preference not by means of the
connecting wires.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append a Sheet of explanatory Drawings,
to be hereinafter referred to, and representing by way of examplo a simple and
convenient mode of practically carrying out my improvements.
Figures 1 and 2 on the accompanying Sheet of Drawings aro front and side
elevations of a spherical block of zinc as suspended in a boiler, and Figure 3 is a
horizontal section. In these Drawings the same reference numerals are used to
mark the same or like parts wherever they are repeated.
The sphere or ball 4 of zinc is cast upon a brass coro 5, formed by preference as
shown with projections 6 radiating from the centre. To one end of this core 5
there is soldered or brazed a copper wire 7, the other end of which is soldered to
the shell of the boiler. The ball 4 is suspended by means of an iron strap 8 from
one of the boiler stays 9, tho ball being held or clipped between the lower ends of
the strap 8 by means of screw bolts 10, and by means of cross pieces 11 riveted to
the strap ends.
Having thus particularly described my said Invention and the manner of
performing the saine, I have to stato that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by and in terms of the berein-
before in part recited Letters Patent is,-
The mode of applying zinc for preventing corrosion in steam boilers in the forms
of blocks or masses of a spherical, or spheroidal, or polyhedral, or cubical form,

page_text: or other form having small difference of thickness in different directions, and
substantially as herein before described.
In witness whereof, I, the said James Ballantyne Hannay, have hereunto set
my hand and seal, this Seventh day of November, in the year of our Lord
One thousand eight hundred and eighty-one.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
J. B. HANNAY. (L.S.)