Improvements in Electrical Apparatus for Preventing Corrosion or Incrustation of Steam Boilers and other similar Vessels, and for Removing the Incrustation when once Formed.
Year: 1887

page_text: Date of Application, 10th June, 1887
Complete Left, 13th Jan., 1888
Complete Accepted, 17th Feb., 1888
Improvements in Electrical Apparatus for Preventing Corrosion or
Incrustation of Steam Boilers and other similar Vessels, and for
Removing the Incrustation when once Formed.
I, AUGUSTUS JOHN MARQUAND, of Bute Docks, Cardiff in the County of Glamorgan
Engineer do hereby declare the nature of this invention to be as follows:-
My Invention relates to an improved method of and apparatus for applying
electricity to steam boilers and other similar vessels for the purpose of preventing the
formation of incrustation, or of removing it if already formed, and also for preventing
corrosion or pitting of the internal surfaces.
It consists firstly in an improved method of applying the electric current to the
boiler; and secondly, in an improved apparatus for carrying out the said method of
applying the electricity.
Numerous proposals have been made from time to time to use electricity for the
same purposes as those of this invention; but up to the present time no importance
has been attached to the direction of the current-that is to say, inventors have as a
rule not cared whether the current has flowed from the water to the shell, or from
the shell to the water. I quote as an example the specification of Letters Patent
No. 2993 of A.D. 1862, in which it is set forth that the current flows from the
internal surfaces of the boiler through the water and out through the insulated
conductor; that is to say, that the terminal of the battery corresponding with the zine
plate thereof is connected with a conductor passed through the shell of the boiler,
and insulated therefrom, into the water space; and that the terminal of the battery
corresponding with the carbon thereof is connected with the shell of the boiler.
Now, according to my invention I lead the current in exactly the reverse direction,
as follows
The terminal of an electric generator corresponding with the zine plate of a battery
is electrically connected in any convenient way and either directly or indirectly with
the shell, while the terminal corresponding with the carbon or iron of the battery is
connected to the conductor which latter is passed through the shell into the water
space, but is electrically insulated from the shell. This inethod will therefore make
the shell negative and the insulated conductor positive, moreover I always use a
continuous current as distinguished from an alternating one,

page_text: I have found that if the current flows in the reverse direction to that specified in
the last paragraph, or if alternating currents be used; local action on, or corrosion
of the inner face of the shell will be increased; but that if the electricity be applied
according to my invention, corrosion cannot and does not take place. Moreover, it
is generally believed that my method of applying an electrical current to a boiler will
not prevent incrustation; but I have proved that incrustration is not only prevented
but that it can be detached after it has already formed.
In carrying my invention into effect, I provide any suitable source of electricity-
say a battery. When my invention is to be applied to a marine I prefer that
the battery case shall be attached to a metal plate which can be bolted to the bulk-
head, and this plate is electrically connected with the negative pole. When the
invention is to be applied to a land boiler the plate is conveniently furnished with a
clip by which it can be suspended from a pipe in connection with the boiler.
not confine myself to this method of fixing the battery as others may be adopted, but
I specify these as both preferable and at the same time convenient, inasmuch as there
will then be only one lead from the battery in the direction of the boiler, viz., the
positive one to the insulated conductor.
I do
This conductor may be made of any metallic substance. It is preferably in the
form of a large knob and is fixed on the end of a stud passed through and fixed to
the shell, but carefully insulated therefrom, conveniently by flanged ferrules of
suitable material. The lead from the battery is attached to the outer end of the
stud conveniently by means of nuts securing the wire to which the terminal is
attached.
During the time my apparatus in use the metallic conductor is worn away and
must therefore be renewed from time to time. To facilitate this renewal, the
conductors are made to screw onto the stud, if preferred up to the flange of the ferrule,
and therefore to act in so far as a lock nut; or I may use a hollow plug of
any suitable
material instead of the stud, and through which plug the conductor is passed and
properly insulated therefrom.
I do not confine myself to any particular number of batteries and conductors, for
this detail is decided by circumstances as well as weather when more than one
apparatus is used, the sets shall be coupled up in series or not.
Dated this 10th day of June 1887.
PHILLIPS & LEIGH,
Agents for the Applicant.

page_text: Improvements in Electrical Apparatus for Preventing Corrosion or
Incrustation of Steam Boilers and other similar Vessels, and for
Removing the Incrustation when once Formed.
I, AUGUSTUS JOHN MARQUAND, of Bute Docks, Cardiff, in the County of Glamorgan,
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 :-
My invention relates to an improved method of, and apparatus for, applying
electricity to steam boilers, and other similar vessels for the purposes of preventing
the formation of incrustation; of removing it if already formed; and also of preventing
corrosion or pitting of the internal surfaces.
The invention consists firstly, in an improved method of applying the electric
current to the boiler; and, secondly, in an improved apparatus for carrying out the
said method of applying the current.
Numerous proposals have been made from time to time to apply electricity for the
purposes of this invention, but up to the present time no importance has been attached
to the direction of the current-that is to say, inventors in this branch of applied
electricity have not cared whether the current should flow from the conductor through
the water to the shell, or from the shell through the water to the conductor.
Now according to my invention, the terminal of an electric generator corresponding
with the zinc plate of a battery, is electrically connected in any convenient way, and
either directly or indirectly, with the shell; while the terminal corresponding with
the carbon or iron of the battery is connected to the conductor, which latter is passed
through the shell into the water space; but is electrically insulated from the shell.
This method will, therefore, make the internal surfaces negative; and the insulated
conductor, positive. I have found, as a matter of fact, that if the current flows in a
direction the reverse of the one above described, local action on, or corrosion of, the
inner surfaces of the shell will be increased; but that if the electricity be applied
according to my present invention, corrosion cannot and does not take place. And as
it is generally believed that my method of applying an electric current to a boiler
will not prevent incrustation, I wish it to be distinctly understood that experience
with my invention proves that incrustation already formed will be removed by it,
and its re-adherence effectually prevented.
In carrying my invention into effect, I provide any suitable source of electricity-
say a battery. When my invention is to be applied to a marine boiler, I prefer that
the battery-case shall be attached to a metal plate which can be bolted to any part of
the boiler or ship, and this plate is electrically connected with the negative pole, or
pole corresponding with the zinc plate. When the invention is to be applied to a
land boiler, the plate is conveniently furnished with a clip by which it can be
suspended from a pipe in connection with the boiler. I do not confine myself to this
method of fixing the battery, as others may be adopted; but I specify these as
preferable, and at the same time convenient; inasmuch as there will then be only

page_text: one lead from the battery in the direction of the boiler, viz., the terminal of the
battery corresponding with the iron or carbon pole to the insulated conductor.
The accompanying figure is a sectional elevation illustrating the construction of iny
improved apparatus, and its connection to the boiler shell.
A is the shell of the boiler electrically connected to the negative pole of the
battery.
B is the conductor. This may be a metal knob, but I prefer to use a perforated box
of any convenient section which is filled with zinc.
C is a ferrule screwed into the boiler shell, and D is an efficient insulation fixed
inside the ferrule and covering both ends of it by means of flanges, or washers, d, d².
E is a stud, to the end of which the conductor is securely attached in any con
venient way. The stud is passed through the ferrule, from which both it and the
conductor are, however, insulated as shewn. A nut, e, on the outer and screwed
end of the stud is provided for the purpose of fixing the conductor firmly in its
position.
F is the lead from the positive pole of the battery coupled to the outer end of the
stud, E.
G is a cap having a perforation, f, through which the positive lead is taken, adapted
to screw onto the ferrule for the purpose of protecting those parts of the apparatus
which it covers from being injured.
An electrical indicator may be placed in the circuit for the purpose of indicating the
existence of the current.
I do not confine mysolf to the number of batteries, circuits, or conductors I make
use of, inasmuch as these may be varied according to convenience. If more than
one apparatus be used on one boiler they may be coupled up in series, if preferred.
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
1. Passing a current of electricity from the positive pole of a battery into the water
in a boiler through a conductor fixed in the boiler shell but insulated therefrom, the
shell being connected electrically to the negative pole of the battery.
2. The combination of metallic conductor; stud to which it is attached ; ferrule
screwed into the boiler-shell; tightening nut adapted to screw onto the outer end of
the said stud; insulation between said ferrule and stud; positive lead electrically
connected to the outer end of said stud; a protecting cap adapted to allow of the
positive lead being passed through it, and to screw onto the outer end of the said
ferrule and a boiler shell electrically connected to the negative pole of the battery.
3. An electric conductor adapted to deliver an electrical current into the water
in a boiler or similar vessel, and consisting of a perforated box filled with zinc.
Dated this 1st day of January 1888.