Improvements in Electrical Apparatus for Prevention of Corrosion and Incrustation in Steam Boilers.
Year: 1887

page_text: Improvements in Electrical Apparatus for Prevention of Corrosion
and Incrustation in Steam Boilers.
I, HENRY WILLIAM RUSDEN, of. 8 Gold Street, Roath, Cardiff, in the county of
Glamorgan, marine engineer, 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:
This invention relates to means whereby, through the employment of an electric
current, hydrogen gas is evolved from water in a steam boiler and corrosion and
accumulation of incrustation are obviated.
It consists in the use of electrodes which are immersed in the water in a boiler to
the extent only of a part of their bodies which are preferably of zine.
The shanks, which are preferably of copper, are not in contact with the water and
hence no local galvanic action takes place in the electrodes, as is the case with
electrodes to the copper and zinc composing which the water has access Such local
action results in destruction of the electrodes.
The current may be generated either between the boiler and the electrodes through
the medium of the water and wires connecting the electrodes to the boiler, or it
In the latter case the electrodes are
may be supplied from an external battery.
charged positively through a wire conducted into the boiler, an insulated conductor
being extended for that purpose through the boiler shell.
The boiler is negatively charged through a wire connected with the opposite pole
of the battery and having a terminal in the boiler shell.
In event of the flow of the current from the battery being interrupted, connection
is then made between the wires outside the boiler by a wire which extends from one
to the other and the action is maintained by galvanisin.
The electrodes may, when desired, be charged negatively for the purpose of
dispersing any oxidation, and in order to prevent the boiler from being at such
times charged positively, the positive current is directed by a commutator through a
wire which is connected to an insulated conductor projecting into the hoiler through
the shell thereof.

page_text: When no external battery is employed, the electrodes are separately connected to
the boiler shell by wires, and galvanic action is set up, the electrodes being charged
positively and the boiler negatively.
Referring to the figure shewn in the accompanying drawing, A is a boiler in
section in which are situated electrodes B the bodies or lower parts of which are
preferably of zinc and the shanks or spindles 6 preferably of copper.
As the two different metals of which the electrodes are composed are not both in
the water, local galvanic action tending to destroy the electrodes is not set up
therein.
The electrodes are electrically connected and are charged positively through the
wire from the battery D which wire is passed into the boiler through the
insulated conductor F.
The boiler is charged negatively through the wire E connected to the boiler by
the terminal e.
As is well understood, the globules of hydrogen gas evolved in the decomposition
of the water collect on the boiler shell and internal parts and so prevent oxidation
and accumulation of incrustation.
Should the current from the battery be interrupted, the wires C and E are then
connected outside the boiler by the wire G and the action maintained in the boiler
by galvanism.
To enable the electrodes to be charged negatively and thus to disperse any
oxidation therefrom and, at the same time, to avoid positive charging of the boiler,
the wire H and insulated conductor I are provided. By the commutator K the
positive current is directed to pass to the insulated conductor I extending into the
boiler, as shown.
When an external battery is not employed, the electrodes are separately connected
to the boiler by wires as indicated by the dotted lines 77, the electrodes being
positively charged and the boiler negatively.
Having now particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, I declare that what I claim is :-
1. The use, for prevention of corrosion and incrustation in steam boilers, of
electrodes or anodes so situated as not to expose two dissimilar metals to the
water whereby local galvanic action in the electrodes is obviated, the arrangement
being such that the boiler is negatively and the electrodes positively charged either
in the boiler or from an external battery, substantially as herein before described.
2. The use in connection with electrodes for prevention of corrosion and
incrustation in boilers, of means such as the wire H connecting a commutator or
switch of an electric battery with an insulated conductor such as I extending into
the boiler, for enabling the electrodes to be charged negatively without involving
positive charging of the boiler, substantially as herein before described.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.