Improvements in Appliances for Preventing Corrosion in Steam Boilers.
Year: 1888

page_text: Date of Application, 17th July, 1888
Complete Specification Left, 16th Apr., 1889
Complete Specification Accepted, 18th May, 1833
R
Improvements in Appliances for Preventing Corrosion in Steam
Boilers.
1, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County of
Dumbarton, North Britain, Chemist, do hereby declare the nature of this Invention to
be as follows, that is to say :-
This Invention relates to the prevention of corrosion in steam boilers and consists
in applying zinc balls, or electrogens as I have named them, of improved construction
in an improved manner, the object being to obtain a more efficient and reliable anti-
corrosive action than heretofore without waste of zinc.
In carrying out my Invention I apply the zinc 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. The ball of zinc is cast upon a core of copper of a special form
hereinafter particularly described, and after casting is hammered or compressed under
great pressure so as to make it as dense as possible. Whilst being hammered or
compressed the zinc should be at a temperature between 120 and 160 degrees, Centi-
grade. The copper core of the zinc ball has conducting wires fixed to its ends and
the other ends of these wires are fixed to the shell or tubes or other part of the boiler,
the ball being immersed in the water in the boiler.
The copper core is made in the form of a bar which at its ends is about one fourth
as thick as it is wide, but this thickness extends a very little way from each end into
the zinc ball, and the middle part is made very much thinner and is twisted to a
greater or less extent. The middle part of the copper core is thinned as described to
prevent it from loosening in the zinc ball by the action of changes of temperature;
and it is twisted so that the crystallisation of the zinc when cooling, and which tends
to proceed outwards from the edge of the core, may be distributed in different
directions and thus diminish the liability to produce cracking.
1000
EDMUND HUNT,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Appliances for Preventing Corrosion in Steam
Boilers.
I, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County of
Dumbarton, North Britain, Chemist, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, that is to say :—
This Invention relates to the prevention of corrosion in steam boilers and consists
in applying zinc balls or electrogens as I have named them, of improved construction
in an improved manner, the object being to obtain a more efficient and reliable anti-
corrosive action than heretofore without waste of zinc.
In carrying out my Invention I apply the zine 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. The ball of zinc is cast upon a core of copper of a special form
hereinafter particularly described, and after casting is hammered or compressed under
great pressure so as to make it as dense as possible. Whilst being hammered or
compressed the zinc should be at a temperature between 120 and 160 degrees, Centi-
grade. The copper core of the zinc ball has conducting wires fixed to its ends and
the other ends of these wires are fixed to the shell or tubes or other part of the boiler
the ball being immersed in the water in the boiler. It is of the greatest practical
importance to have the conducting wires fixed to the electrogen ball and to the parts
of the boiler so as to secure complete metallic union. For this purpose the conducting
wires which should be of copper or other metal or alloy that is a
good conductor of
electricity, should be united to the copper core of the electrogen ball by careful
welding or soldering; and solder must be carefully applied where the wires are fixed
to the boiler. An effective mode of fixing each wire end to the boiler consists in
fixing a screw or rivet in a hole drilled in the boiler shell or other part, and fixing
the wire to the screw or rivet, perfect metallic union being secured by solder
applied both between the wire and the screw or rivet and between the latter and the
boiler.
On an accompanying sheet of explanatory drawings, figure, 1, is a sectional end
elevation of a marine boiler showing the mode of applying the electrogen. Figure, 2,
is an enlarged section of the electrogen, and figure, 3, shows the core separately and
as at right angles to the position in which it is shown in figure, 2.
The copper core, A, is made in the form of a bar which at its ends is about one
fourth as thick as it is wide, but this thickness extends a very little way from each
end into the zine ball, C, and the middle part, B, is made very much thinner and is
twisted to a greater or less extent. The middle part of the copper core is thinned as
described to prevent it from loosening in the zinc ball, C, by the action of changes

page_text: of temperature; and it is twisted so that the crystallisation of the zinc when cooling,
and which tends to proceed outwards from the edge of the core, may be distributed
in different directions and thus diminish the liability to produce cracking.
The electrogen, C, may be held in the boiler in any convenient way. As shown
in figure, 1, it is suspended from a stay, D, by metal straps, E, and one of its con-
ducting wires, F, shown as fixed to the outer boiler shell, the other, G, being fixed
to a furnace shell or flue.
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 :-
As a means of preventing corrosion in steam boilers zinc electrogens or blocks of
spherical, or spheroidal, or polyhedral, or cubical, or other similar form, such blocks
being cast upon copper cores having their middle parts extremely thin and twisted,
and being subjected to compression after being cast, and the cores being metallically
connected to parts of the boilers, substantially in the improved manner hereinbefore
described.