Improvements in Electrodes and Electrode Connections, in Liquid Feed Devices, and in the Construction of Enclosing-vessels for Electrolytic and Kindred Apparatus.
Year: 1899

page_text: Date of Application, 16th May, 1899-Accepted, 15th July, 1899
COMPLETE SPECIFICATION.
Improvements in Electrodes and Electrode Connections, in Liquid
Feed Devices, and in the Construction of Enclosing-vessels for
Electrolytic and Kindred Apparatus.
I, HENRY CARMICHAEL, of Malden, Middlesex County, Massachusetts, U.S.A.,
Consulting Chemist, having a place of business at Number Twelve, Pearl Street,
Boston, Suffolk County, Massachusetts, U.S.A., 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:―
The objects of the invention herein described are the provision of improved
electrodes and their connections for electrolytic and analogous apparatus wherein
precautions against corrosion of the conductors and their contact joints are
rendered necessary by the character of the substances which are subjected to the
process carried on in the apparatus or which form products of the process.
A typical example of such apparatus and processes will be found described in
my Patent for a method of and apparatus for electrochemical decomposition,
No. 8061, dated April 24, 1894; the process therein described for obtaining the
products of electrolysis of a solution of sodium-chloride is characteristic in that
the caustic alkali and chlorine which are developed in the course of the process
are substances which, in the presence of the electric current become exceptionally
troublesome by reason of their corrosive activity and the persistence with which
they insinuate themselves into and through the most carefully prepared and
protected joints in an apparatus, and their capacity for destroying in the most
unexpected manner, materials which under ordinary conditions, are confidently
regarded as inert and refractory. My present invention will therefore be described
and illustrated in connection with a sodium chloride electrolysis and apparatus
therefor, although doubtless they will be found useful and adaptable in other
situations.
The cathode construction of the apparatus shown in my patent aforesaid has been
found to offer no difficulties in construction or operation, but the predicament of
the anode, which is subjected to the action of free chlorine in the presence of an
electric current, is very different.
The anode of the apparatus thus described has proved fairly effective and
economical, and has demonstrated by prolonged commercial working on a large
scale that its fundamental scheme of arrangement and construction is correct.
Broadly speaking, the anode of the patent aforesaid is an electrode which
consists of two systems; first, an internal system of corrodible conductors sur-
rounded and insulated by non-corrodible material; second, an external system
of uninsulated non-corrodible conductors, the internal and external systems being
connected electrically by non-corrodible metallic pins, which pass through the
insulation of the internal system in such manner as to exclude all corrosive
agents from the internal system while maintaining and preserving good electrical
contact with the external system.
By this arrangement such non-corrodible metallic conductors as platinum arc

page_text: used with a minimum expense, the cheaper corrodible conductors being used
to the point where exposure of the conductor is essential to the carrying on of
the process.
The improvements which form the subject matter of the present description
involve the invention of the general scheme outlined in the patent aforesaid
and consist of improvements in the structural arrangement by which the general
two system scheme shall be rendered more effective and its adoption more con-
venient, and in the special construction of the internal system of corrodible
conductors enveloped in non-corrodible non-conductors.
The specific mode of carrying this general scheme into effect which is described
in my patent aforesaid consisted in the use of a copper wire encased in a lead
tube which was in turn encased in a rubber sleeve. Through the lead and rubber
were driven short platinum pins, which served as pegs on which to stretch the net-
work of fine platinum wires which completed the metallic portion of the exposed
electrode.
The covering and insulating materials which encased the copper wire, viz.
rubber and lead, were such as had proved adequate in other structural combina-
tions to resist the action of chlorine and salt solutions in apparatus previously
used, and were adopted confidently for my apparatus and process. But the
process described in my patent aforesaid differs radically from prior processes in
that it is continuous instead of intermittent and therefore involves a higher
concentration of the products of electrolysis than had theretofore been practicable
in non continuous and non progressive electrolysis.
There was, therefore, a far more severe demand made upon the apparatus and
its component parts than in prior apparatus and the frequent opportunities for
examination and renewal of worn out portions which the interruptions of inter-
mittent processes has afforded in older apparatus were withdrawn when the
apparatus of my patent aforesaid went into commercial use. The process of that
patent is and proved to be permanently continuous, and called for an apparatus
which should be as nearly as possible indestructible.
The continuity of the process soon developed the fact that improvements in
the anode were necessary in order to render that part of the apparatus as durable
as the other part.
The new condition exacted requirements in structural features which had not,
so far as I am aware, developed in the use of apparatus for intermittent and non
progressive electrolysis. While the specific form of anode described in the patent
aforesaid performed its office perfectly well for a time, (for a much longer time
when the periods of activity in intermittently operated apparatus), that form
of anode proved in practice to be structurally the relatively weak point in the
system, when compared with the rest of the apparatus, which has proved to be
practically more permanent.
The constant action of chlorine in solution developed unusual and unexpected
irritant capacity in the presence of the electric current, which seems to give the
chlorine and the chlorinated solution the power to insinuate themselves into the
very body of the insulator. This phenomenon also developed itself in experi-
menting with other insulators than rubber, even glass showing a tendency after
a while to crackle into minute granules; the interstices between the granules
gradually permitting the solution to penetrate to the corrodible conductor which
was enclosed by the glass. Glass tubes may however be considered fairly
effective in the structural arrangement hereinbelow described, although when
the apparatus is used for the continuous electrolysis of sodium chloride another
substance is to be preferred, and enters into the subject matter of invention
hereinbelow described.
The above, and similar experiments, showed conclusively that substances which
under ordinary conditions are good permanent insulation, under the conditions
which prevail in an electrolytic apparatus, are short lived and ineffective.
My invention hereinbelow described consists of first; an electrode constructed

page_text: on the internal and external system, having for its protective portion a material
discovered to be practically permanent as an insulator under electrolytic con-
ditions, and second; an arrangement of an electrode of the two system type
which, aside from the special materials of which it is composed, possesses increased
advantages and novel characteristics, due to constructive features rather than
to the selection of special materials.
Also the construction of the enclosing vessels of electrolytic apparatus and
provides an enclosing vessel which possesses such resistant and inert quality as
to sustain itself against the attacks of certain corrosive agents which have hereto-
fore proved troublesome especially when the electrolytic process to which they
are incident is prolonged. The improved vessel presently to be described I have
found useful especially in connection with the electrolytic process referred to.
In electrolysis of a solution of sodium chloride by the process described in the
aforesaid patent the products of the process are carried to and maintained at a
high degree of concentration by virtue of the continuity and progressive character
of the process, and the corrosive effects of these products, especially when assisted
by the electric current and the high temperature caused by the internal resistance
of the electrolytic cell have proved to be destructive even of substances which
are usually regarded as inert.
Also to devices for feeding liquid to electrolytic apparatus or to any vessels
where such electrical conditions prevail that it is important to guard against
accidental leakage of electricity through the liquid contact of a continuous stream
to an external supply tank and elsewhere, and where, also, the nature of the
process carried on demands a substantially constant supply of liquid.
The invention accomplishes this object and insures a feed supply of constant
volume at all times, no matter how much the level of liquid in the reservoir
from which the supply is drawn may vary above a predetermined lower limit.
This invention broadly speaking, involves the idea of regularly rotating or oscil-
lating feeding scoops or tubes.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a vertical cross section and perspective view of the upper part of an
electrolytic cell, showing the anode construction.
Fig. 2, is a detail showing one of the leading in drop tubes of Fig. 1 in
cross-section, and
Fig. 3 is a detail showing an arrangement of individual electrodes.
Fig. 4, is a plan view of an electrode attached to the device shown in Fig. 3.
Fig. 5 shows a simple box shaped form of such an enclosing vessel for such
apparatus as has been referred to in connection with the said electrolytic process
with its cover but the shape of the vessel may be indefinitely varied to suit the
notions of the builder of such apparatus. "
Fig. 6 shows in elevation and partly in cross-section one of the improved
feeding devices with the tank and receiving funnel; and Fig. 7 shows in per-
spective one of the feeding devices with the actuating shaft and the mechanism
whereby the shaft is given a regular rotative or oscillating movement.
In Fig. 1. the upper portion of an anode compartment is shown in perspective
and vertical cross section. A full representation of an electrolytic apparatus
containing an anode chamber like the one partially shown in Fig. 1. may be
seen in Fig. 2 of my patent aforesaid. The walls and cover of the anode chamber A
are composed of slate or other proper material and the cover thereof is pierced
at suitable intervals for the passage of pocket shaped ducts T which, penetrate
into the anode chamber so that their lower extremities pass below the level of
the electrolyte in the anode chamber which is indicated in Fig. 1 by the dotted
line m.
Fig. 2 shows in cross section on an enlarged scale one of the pocket shaped
ducts T. The specific form of pocket duct. used herein for illustration, is a
tube B, closed at its lower end and open at its upper end; in general shape like

page_text: "
the ordinary test tube of the laboratory. This is a form which I consider
advantageous because of its simplicity and the ease with which each pocket shaped
duct of this form can be manipulated, in making electric connections inside and
outside, and in attaching to the cover of the apparatus. At the closed end of
the tube T, which I term a "drop tube a short pin P of non-corrodible con-
ducting material such as platinum is fused into the wall of the drop tube or
otherwise hermetically sealed therein, preferably by the material of which the
tube is composed, leaving the ends of the pin emerging from the wall of the drop
tube, one end protruding therefrom into the electrode compartment of the
apparatus the other end intruding within the drop tube itself; the protruding
end of the pin I is adapted to the attachment of the exposed portions of the
electrodes. A conducting wire C composed of copper or some other corrodible
conductor, which is inexpensive, as compared with the non-corrodible conductor
is electrically attached to the intruding end of the pin P, and leads therefrom
out of the external end of the tube T and, as shown in Fig. 1, is attached to
the feed wire L, or a branch L' therefrom. In order still further to secure the
permanent insulation of the conductor C the tube T may be filled or packed with
a viscous insulating material D, such as asphalt, resinous substances or such
paraffinoid products as ceresite, or mixtures of such substances.
The melting point of ceresite I may raise by admixture of canaiiba wax. The
operation of an electrolytic apparatus usually involves a considerable rise in
temperature which increases the fluidity of the viscous insulator which has been
run into the tube T so that if there should happen to be formed any break or
interstice in the wall of the drop tube T the viscous material D will by its
increased fluidity offset any tendency of the electrolyte to penetrate to the
conductor C. This precaution while entirely commendable is however probably
unnecessary provided a reliable material is used in the construction of the drop
tube T or equivalent pocket shaped duct, so that the arrangement shown in
Fig. 3, where no viscous insulation is employed may be adopted without fear of
diminishing the protection which must surround the conductor C.
The arrangement of the actively operative electrode may be such as shown in
Fig. 1, where platinum wires W are strung from the pins P and form a net work
horizontally disposed in the electrode chamber A, in which case the electrode is
electrically a unit. An arrangement which is, however, I believe to be preferred
is that shown in Figs. 3 and 4 where each drop tube carries a separate and
independent electrode composed of wires which radiate from the pin P as a
central support. The form which I prefer for these individual electrodes consists
of a group or rosette composed of several radiating loops W of platinum wire
which can be fused to the pin P. The shape of the area covered by the radiating
loops should be determined by the disposition of the drop tubes T, the object
being to cover thoroughly the entire area in the electrode chamber; so if the
drop tubes T are arranged as in Fig. 1, each one of the loop rosettes should
occupy an area substantially square, and all the rosettes will in the aggregate
cover the available surface. For this purpose the arrangement shown in Fig. 4,
is preferred where the diagonals of the square are covered by long loops and the
diameters of the square by the shorter loops.
The advantages of the form of electrode and electrode connections above
described can be secured by the use of any insulating material in the construction
of the pocket shaped ducts, and these advantages will persist as long as the
material lasts. The material which I have adopted for use in connection with
electrolysis of common salt solution after observing the unexpected failure of
sundry substances which had been confidently relied on to perform their function
satisfactorily and permanently, is vitrified non absorbent porcelain.
"Vitrified porcelain is porcelain which is "fritted" together in all its parts,
as distinguished from being merely glazed on the surface.
Glazed porcelain is non-absorbent to the extent of its superficial protection.
but the interior remains absorbent, like biscuit ware. A non-absorbent vitrified

page_text: 'porcelain has the glaze effect all the way through its mass, and is proportionately
effective for such insulation as the situation under discussion demands.
The quality is one which may vary in degree and correspondingly in effective-
ness of insulation. Owing to the persistent and searching action of chlorine in
the presence of an electric current, even such a universally accepted insulator
as glass eventually disintegrates and permits the substances in solution in the
apparatus to have access to the unprotected corrodible conductor. Experience
with sundry insulating materials has demonstrated that ordinary precedents cannot
be relied on where the selection of material for an insulator in connection with
the process described in my patent aforesaid is concerned, and I have discovered
that, unlike' rubber and glass vitrified porcelain is permanently reliable under
the trying conditions which prevail in my process aforesaid and therefore in
the construction of electrode connections of whatever form I use this porcelain
as the insulating material for the protection of corrodible conductors. Again
referring to the form of electrode connections which involves the use of the
pocket shaped duct, I have found in practice that the platinum pin P, can be
strongly and securely sealed in the porcelain where that is the material used by
inserting the pin in the porcelain before it is baked and then baking the pin
into the porcelain which in becoming vitrified fuses into close adhesive contact
with the pin.
Another form of porcelain which is "vitrified" so as to furnish substantially
the same effective qualities is that which is termed "hot cast" porcelain, in
which the glaze element is more predominent than in the porcelain made in the
usual manner.
The enclosing vessel shown in the drawings by Fig. 5 consists of sides A*,
ends B, and cover C, all these being simple slabs which may be moulded readily
out of a material which after persistent experiment and the observation of the
behaviour of several substances in commercially operative apparatus I have
discovered meets admirably all the exacting requisitions of the situation.
In the construction of the enclosing vessels described and referred to in connec-
tion with Fig. 5 first a suitable thick paste is made with water, Portland or an
analogous cement, and fine sand, preferably a sand made of crushed quartz which
appears to bind with the cement better, than other such material. A good
working proportion is one part of cement to two parts of sand or quartz but
these proportions may be varied with good results so long as the cement constitutes
the effective ingredient of consistency. The cement is the essential material
which possesses the desired qualities, and the paste may be made of cement alone
with all the desired results. Out of this paste or concrete the enclosing vessel
for electrolytic apparatus is moulded in any desired form either as an integral
structure or as parts to be fitted together, and is then allowed to set. The structure
resulting from this method and these materials is abundantly strong, and wholly
inert in the presence of such corrosive substances as caustic soda and chlorine
even when their destructive operations are facilitated by the presence of an electric
current, and the high temperature incident to the maintenance of the process.
Referring to Figs. 6 and 7, A is the reservoir over which the shaft S is suspended
in suitable bearings. Upon the shaft S, pipes C are securely mounted so that
as the shaft rotates or oscillates the pipe will be carried with it. As many feeding
devices as are required may be attached to the shaft S; but as this involves mere
reduplication, only one of the feeding devices is shown in the drawing. The
scoop or pipe is so proportioned with reference to the shaft on which it is mounted
and the reservoir into which it is to dip that the bowl or scoop of the pipe shall
always pass beneath the surface of the liquid in the reservoir so long as that
level does not fall below a reasonable working point. The dipping end of the
pipe is bowl or scoop shaped, the mouth of the bowl or scoop being at L, L':
the bowl or scoop being curved up from the pipe in much the same manner as
the bowl of a Dutch tobacco pipe curves up from its stem.
The stem of the pipe C extends from the bowl to' and beyond the shaft S and

page_text: terminates in the delivery opening M, the entire pipe having a continuous and
uninterrupted bore. In order that the pipe shall, notwithstanding variations in
the level of liquid in réservoir, invariably deliver a uniform quantity to the
receiving funnel B which leads to the electrolytic or other apparatus, the volume-
tric capacities of the scoop and stem parts of the pipe are so proportioned that
the volume of contained liquid in the pipe at that point in its rotation or oscilla-
tion when the delivery opening M begins to spill into the funnel B shall not
be greater than the volume of contained liquid standing in the pipe at all points
in its rotation or, oscillation between the beginning of delivery spill and the point
where the mouth of the pipe at the scoop end emerges from the liquid in the
reservoir. This may be explained by reference to Fig. 6.
Assuming the level of the liquid in the reservoir to be at the dotted line a.
the pipe C shown in solid lines, is just at the point of emersion from the liquid
in its oscillation from the lowest position shown in dotted lines at C¹ toward its
highest extreme position shown in dotted lines at C³. The scoop part and stem
part should be so proportioned as to their relative volume that the contained
liquid at the position of emersion shall be at least as great in quantity as the
contained liquid when the pipe reaches that angle when the liquid begins to spill
from the outlet opening M. If this proportion is observed, the quantity of liquid
delivered at each oscillation of the pipe C will be the same, even though the liquid
in the reservoir A should fall as low as the dotted line b. For, as is obvious
from a glance at Fig. 6, more liquid will be contained in the scoop part of the
pipe as it emerges from the level B, than is contained in the scoop part at the
point of emersion when the level is at a while, in the stem part of the pipe C,
a larger proportion of liquid is contained at the point of emersion with the level
at a than with the level at b. So if these two parts, the scoop and stem, are
so proportioned that the stem part cannot accommodate the liquid which flows
from the scoop part as the angular position, of the pipe is changed, then, when
the pipe reaches the point of spill from the delivery end M, the liquid in the scoop
part will be just level with the inner side L of the mouth or lip of the scoop,
no matter what the level of the liquid in the reservoir may be. A simple manner
in which to insure this proper disparity in proportion between the scoop part
and stem part of the pipe P is to make the scoop part much larger than the
stem part, and then to cut the mouth of the scoop at an acute angle so that the
outer side L' of the lip or mouth in the movement of emersion of the scoop is
considerably in angular rotative advance of the inner edge of the scoop opening L,
which is nearer to the axis S than the protruding part L. With this arrange-
ment, the scoop will pick up a liberal surplus when the liquid is at a low level,
and this surplus, as the scoop rises, will be spilled back into the reservoir.
In Fig. 7 the shaft S, to which the pipes C are attached, is shown with a
crank Sat its outer end, whereby the shaft is given an oscillating movement
by means of the connecting rod S2 and wheel $3; an oscillating movement is
substantially, however, the same as a complete rotative movement, and the liquid
feed apparatus may easily be adapted for use on a continuously rotating shaft,
with slight modifications to provide for a proper delivery to receiving funnels,
which, in that case, would be inside instead of outside the tank.
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. The combination with the enclosing case of a cell for electrolytic or kindred
purposes of an introductory conduit for electrode connections, the said conduit
consisting of a pocket shaped duct made of insulating material passing, through
the enclosing case, a pin of non corrodible conducting material passing through
and sealed in the wall of the pocket within the case and protruding from both
sides of the wall, a conductor in electrical contact with the said pin on the inside
of the pocket, and leading therefrom through its external end.

page_text: 2. An introductory conduit for electric connections which consists of a tube
of insulating material, open at one end and closed at the other end, a pin of
non-corrodible conducting material sealed in the wall of the tube at its closed
end and protruding from the wall both on the inside and outside of the tube,
and a conductor in electrical contact with the said pin on the inside of the tube
and leading therefrom through the open external end of the tube.
. 3. The combination with the enclosing case of a cell for electrolytic or kindred.
purposes, of a plurality of introducting conduits for electrode connections each
of the said conduits consisting of a tube of insulating material closed at one end,
passing through the enclosing case and having its open end outside and its closed.
end inside the case, a pin of non-corrodible conducting material passing through
and sealed in the inner end of the insulating tube, and protruding from the wall
of the tube both inside and outside, and having an electrical conductor in contact
with the inner end of the pin and leading through the open end of the tube, and
wires strung between the exposed ends of the several pins.
4. An electrode connection which consists of a corrodible conductor surrounded
and contained by a non-corrodible insulating tube closed at one end, a non corro-
dible conductor embedded in the material of the said tube, having its uninsulated
ends emerging therefrom, the corrodible conductor joined electrically to the
intruding end of the non-corrodible conductor within the insulating tube and
leading therefrom to the open end of the said tube.
5. An electrode connection which consists of a tube of insulating material,
closed at one end and open at the other, a pin of non-corrodible conducting material
passing through and sealed in the closed end of the tube, a corrodible conductor
passing into the open end of the tube and in electrical contact with the intruding
end of the non-corrodible pin and a filling of non-conducting viscous material
enclosing the corrodible conductor.
6. An electrode and connections thereto which consist of a tube of insulating
material closed at one end and open at the other, a pin of non-corrodible con-
ducting material passing through and sealed in the closed end of the tube, intrud-
ing within and protruding from the said tube, a non corrodible conductor attached
to and radiating from the protruding end of the pin, a corrodible conductor in
contact with the intruding end of the pin and passing out through the open end
of the tube and a filling of viscous insulating material within the tube enclosing
the corrodible conductor.
7. An introductory conduit for electrodes which consists of a corrodible con-
ductor surrounded and insulated by a jacket of vitrified porcelain, a non-corrodible
conductor passing through and scaled in the porcelain jacket, electrically joined
to the corrodible conductor inside the jacket, and protruding from the outside
of the jacket.
8. An introductory conduit for electrodes which consists of a tube of vitrified
porcelain, closed at one end, a pin of platinum passing through and sealed in
the closed end of the tube, a copper conductor within the tube, joined electrically
to the intruding end of the platinum pin, and a filling of asphalt in the tube,
enclosing the copper conductor.
9. An enclosing vessel for electrolytic apparatus of which Portland or analogous
cement constitutes the effective ingredient of consistency.
10. An enclosing vessel for electrolytic apparatus made of a concrete composed
of Portland or analogous cement and sand.
11. An enclosing vessel for electrolytic apparatus made of a concrete composed
of Portland or analogous cement, and a sand made of crushed quartz.
12. In a liquid feed apparatus, the combination of a reservoir, a pipe having an
axis of rotative movement, a scoop end, a stem and a delivery opening, and so
mounted with reference to the reservoir that the rotative movement of the pipe
carries the scoop end below the level of liquid in the reservoir, the relative
proportions of the scoop and stem parts of the pipe being such that the volume
of contained liquid in the pipe at and after emersion from the liquid in the tank

page_text: is at least equal to the volume of contained liquid in the pipe when the pipe is
at that point in its rotative movement when the delivery opening begins to spill.
13. In a liquid feed apparatus, the combination of a reservoir, a pipe having
an axis of rotative movement, a scoop end, a stem and a delivery opening, and
so mounted with reference to the reservoir that the rotative movement of the
pipe carries the scoop end below the level of the liquid in the reservoir, the scoop
end having its opening so placed with reference to the rotative movement of the
pipe that, in the movement of emersion, the part of the scoop opening farthest
from the axis is in angular rotative advance of that part of the scoop opening
which is nearest to the axis.
WM. BROOKES & SON,
55/56, Chancery Lane, London,
Agents for the Applicant.