Year: 1897

page_text: I, JAMES HARGREAVES, of Farnworth-in-Widnes, in the County of Lancaster,
Chemical Engineer, do hereby the nature of this invention to be as follows:-
This invention relates to the production of electrodes from pieces of carbon
of suitable sizes and shapes built up or assembled together so as to assume the
form desired.
In constructing electrodes according to my invention, I prefer to employ
pieces of gas-retort carbon having their surfaces "trued," so that when placed to-
gether, the said pieces may fit accurately and form a close joint. The pieces may
be either planed to a true surface or be turned as found convenient. The pieces
of carbon so treated are then built up or assembled so as to constitute walls,
floors, columns, or arches. In order to ensure the complete distribution of the
current through the several pieces of carbon, the conductivity of the electrode
may be increased by inserting a layer of plumbago, in a powdered condition, in
the joints; or sheets of lead, platinum, or other suitable conducting material
may be employed. The conducting material may be protected from the action of
the liquid in the cell by means of a suitable cement.
The said pieces of carbon are retained in position by means of screws or wedges
which may be disposed either inside or outside the cell. The cell may be con-
structed of Portland cement, or other suitable material, and strengthened if
found requisite by a framework of metal. The electrodes, either in the form of
columns or of arches, may be supported by casting their extremities into or through
the sides of the cell.
I, JAMES HARGREAVES, of Farnworth-in-Widnes, in the County of Lancaster,
Chemical 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 the production of electrodes from pieces of carbon
of suitable sizes and shapes built up or assembled together so as to assume the

page_text: "
The accompanying drawings illustrate various modes of carrying my invention
into effect. Fig. 1 is a longitudinal section of a portion of a cell in which the
electrodes are shown as consisting of columns either composed of pieces of carbon
trued" at their junction surfaces or of rough pieces of carbon, retained in
position by screws which are connected to blocks of carbon which pass through
the upper wall of the cell and also serve as conductors for the electric current.
Fig. 2 is a longitudinal section of a similar arrangement of electrodes wherein
the carbon conductors pass through the floor of the cell. Fig. 3 shows a portion
of a cell wherein the conductors pass through both the upper wall and the floor
of the cell; the advantage of this construction being that a lower voltage is
required in consequence of the current having only to travel half or approximately
half the length of the column. Figs. 4 and 5 are respectively a longitudinal
and a transverse section of a portion of a cell wherein the columns
are retained in position by wedges; the conductor being embedded
in the floor of the cell. Fig. 6 is a longitudinal section of a por-
tion of a cell wherein the electrodes are constructed in the form of
arches; same being supported by extensions cast in the side walls of the cell
to which extensions the conductors are connected. Fig. 7 is a view of a similar
construction of electrode, the conductors being embedded in the side walls of
the cell.
In constructing electrodes according to my invention, I prefer to employ pieces
of gas-retort carbon A having their surfaces a "trued," so that, when placed
together, the said pieces may fit accurately and form a close joint.
The pieces
may be either planed, turned, ground or scraped, to a true surface as found con-
venient. The pieces of carbon so treated are then built up or assembled so as
to constitute walls, floors, columns, or arches, examples of columns and arches
-being shown in the drawings. The pieces of carbon may however be assembled
without previous treatment for "truing "their junction surfaces. In order to
ensure the complete distribution of the current through the several pieces of
carbon, the conductivity of the electrode may be increased by inserting a layer
of plumbago, in a powdered condition, in the joints; or sheets of lead, platinum,
or other suitable conducting material may be employed with the same object.
The conducting material may be protected from the action of the liquid in the
cell by means of a suitable cement applied at the edges of the joints as will be
readily understood by those familiar with the employment of electrodes such as
herein referred to.
The said pieces of carbon are retained in position by screws B or wedges B¹
which may be disposed either inside or outside the cell. The cell C may be con-
structed of Portland cement, or other suitable material, and strengthened if
found requisite by a framework C₁ of metal. The electrodes, either in the form
of columns or of arches, may be supported by casting their extremities A¹ into
or through the sides of the cell.
I prefer to employ screws, as shown in Figs. 1, 2 and 3, as affording the better
means of retaining the pieces of carbon in position; the screws passing through
a fixed plate such as shown at b. A are extensions of the carbon blocks, which
pass through the wall of the cell; and which receive the cap a¹. In Figs. 1, 2
and 3 the end of the retaining screw bears upon the cap, the conductor D being
connected with the plate b. In Figs. 4, 5 and 7 the conductor ]) is brought
through a carrier D embedded in the wall of the cell and with which the
extension A¹ is in connection.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I claim :-
"
1. An electrode composed of pieces of carbon, having either "trued or rough
surfaces, assembled in the form of walls, floors, columns or arches, and retained
in position by means of screws or wedges, substantially as herein described.
2. An electrode composed of pieces of carbon, having either "trued" or rough

page_text: surfaces, assembled in the form of walls, floors, columns or arches, retained in
position by means of screws or wedges and having a layer of conducting material,
such as powdered plumbago, inserted in the joints, substantially as and for the
purposes set forth.
3. An electrode composed of pieces of carbon, having either_ trued or rough
surfaces, assembled either in the form of columns or of arches, and supported
by casting the walls of the cell about the extremities of the said columns or
arches, substantially as herein described.