Year: 1896

page_text: Date of Application, 22nd July, 1896
Complete Specification Left, 14th Nov., 1896-Accepted, 9th Jan., 1897
I, WALTER ROWBOTHAM, of 27 Vittoria Street, Birmingham, in the County of
Warwick, Electrical Engineer, do hereby declare the nature of this invention to
be as follows:-
This invention has reference more especially to two-fluid primary electric batteries
in which carbon and metal (such as iron or zinc) elements are employed.
According to my present invention the gas or gases generated during the
working of the battery, instead of being allowed to escape, are permitted to collect
within the battery and are utilised to assist in effecting depolarization.
For this purpose I construct the battery with an hermetically closed outer vessel
or casing which I so form that it will not burst or become fractured by the internal
pressure that is produced during the working of the battery. I find that this
internal pressure is not so much due to the generation of gases within the battery
as to the increase in the bulk of the solution in the carbon element cells, owing to
the formation of water. This increase in bulk causes a very great pressure to be
exerted within the enclosing casing such pressure becoming eventually so great that
the enclosing casing is unable to resist it and consequently bursts. I therefore
provide my improved battery with means whereby this "hydraulic" pressure
is avoided, so that the enclosing casing will not be subjected to any internal strain
from this cause.
In one construction of my improved battery the outer vessel or casing is provided
with a vertical partition dividing it into two main compartments. One of these
compartments contains the elements, and I term this the "active compartiment," and
the other compartment, from which the carbon elements are supplied with fluid,
I term the "reservoir." The said active compartment and the reservoir are sub-
divided by transverse partitions into any desired number of sub-compartments or
cells. The sub-compartments in the active compartment and the reservoir are
capable of communicating with each other by means of passages for the purpose of
facilitating the simultaneous filling or emptying of all the cells of the battery with
the liquids. These passages are provided with special contrivances as hereinafter
referred to for enabling them to automatically open at each filling operation and
close again after such operation has been completed.
The aforesaid reservoir is provided with a subsidiary compartment which may be
produced by a vertical partition having overflow openings at its upper end. This
compartment is not filled with liquid when the battery starts working aud is of such
capacity that it will suffice to receive all the liquid that overflows from the reservoir
when the said liquid increases in bulk as already stated.
The carbon elements are preferably of tubular or hollow form and are
advantageously arranged, in this construction of battery, horizontally or
approximately so, some of them extending into the reservoir and others passing
through the said reservoir and extending into the subsidiary compartment. These
holiow carbors are open at their ends that extend into the aforesaid reservoir and
subsidiary compartment, and are closed at their opposite ends, and those of them
that extend into the said subsidiary compartment are so arranged that the liquid in
the reservoir can pass through openings in the main partition and reach the outer

page_text: surfaces of the said carbons. In this manner the liquid surrounds the exterior of
all the hollow carbons and enters the interior of those that do not extend into the
subsidiary compartment, the interior of these last mentioned carbons being acted
upon only by the liquid that overflows into the subsidiary compartment. I am thus
able to utilize the overflowing liquid an that it is completely spent before being
drawn off from the battery.
I may employ porous plates or partitions for dividing the carbon elements from
the metal elements; or the said carbons may be surrounded by porous tubes which
are of greater internal diameter than the carbons so that an annular space is left
between the carbons and the porous tubes.
Sometimes instead of employing carbon tubes I deposit carbon on the interior
and exterior of the porous tubes.
The aforesaid carbon elements are advantageously arranged in two or more
vertical rows with the iron or other metal clements between such rows. A copper
or other current collecting plate is employed for connecting all the carbou elements
together.
The fluids that I find advantageous for use with this battery are, for the iron
elements, composed of a solution of any alkaline salt such as sal-ammoniac or
nitrate of soda, and for the carbon elements, a mixture of sulphuric and nitric acids.
Other exciting and depolarizing fluids or gases may however be employed.
For the purpose of enabling all the cells of the active compartment and all the
sub-compartments of the reservoir to be filled with active fluid simultaneously as
already stated and yet not allow one cell to short circuit another during the working
of the battery, the hottom of the outer vessel or chamber of the battery is according
to one method formed with cavities into which enter, without extending completely
to the bottom thereof, the lower ends of each of the partitions that divide the
reservoir and active compartment into sub-compartments. Into these cavities I
place a substance that has a higher specific gravity than the active fluid employed,
that is a bad electric conductor, and that is not materially affected by the active fluid.
I have found that carbon bisulphide will answer my purpose when I use the active
fluids above mentioned. Instead of this substance I may however use an insoluble
substance such as sand. Such substance will permit the exciting fluid poured into
one compartment to flow into the next, and so on in succession, but will return to
their position at the bottom of the aforesaid ea vitios when the filling operation bas
been completed and when the level of the exciting fluid in the various compartments
is approximately the same. A seal is thus produced between one compartment and
another.
According to another method, passages are formed in the bottom of the battery
chamber, these passages leading from one side to the other of each partition.
A ball or other valve is provided in each of these passages and the said valve opens
and permits the fluid to flow from one compartment into another during the filling
or the emptying operation, but closes at other times.
According to a modification of my improved battery, the aforesaid reservoir is
provided with a vertical partition which is so arranged that an air tight compart-
ment is formed in front of the open ends of the said carbon tubes. This air tight
compartment is provided with a number of small perforations at its lower end, or is
otherwise formed, so as to communicate with the liquid in the said reservoir. By
reason of the air (or the gas generated when the battery is working) being unable
to escape the said liquid can only rise to a small extent within this air tight
compartment and consequently the interior of the carbon tubes near the upper
portion of the battery becomes filled with gas instead of liquid, and this gas by
finding its way through the pores of the carbons, acts as a depolarizer. When
porous tubes are employed with this construction of battery, they are preferably
closed at their ends which are in proximity to the airtight compartment, and when
so closed perforations are formed in them for the liquid in the metal compartment
to enter the said porous tubes.
According to a further modification of my improved battery I may arrange the

page_text: aforesaid carbon tubes vertically with only their lower portion dipping into the
solution which is contained within a compartment at the bottom of the outer
vessel. The upper ends of these carbon tubes may project through the outer vessel
and are closed. The porous tubes surround the carbons and terminate at their
upper ends in a compartment at the top of the outer vessel and at their lower
ends open into the aforesaid compartment at the bottom of the outer vessel. As
the level of the liquid in the carbon tube compartments does not, even when it
increases in bulk during the working of the battery, rise enough to fill such
compartments I am able to dispense with the subsidiary or overflow compartment
mentioned in the previously described batteries.
The metal element is placed in the space above the bottom compartment and it
will be seen that the two fluids used in the battery are separated by the before
mentioned partitions and the porous tubes.
Lateral openings are formed in the carbon tubes at the part where they pass
through the upper compartments so that the gas arising in said tubes can readily
reach such compartments.
The outer vessel is provided with a cock which is situated at a point somewhat
above the bottom compartment, so that when this compartment is being filled the
level of the solution therein will rise a short distance in the aforesaid porous
tubes.
Instead of employing the active fluids in the form of solutions I may sometimes
use them in conjunction with some absorbent or similar substance that will enable
them to be used in a semi-liquid or plastic condition.
For instance I may employ "Kieselguhr" which is a substance composed
principally of silica, magnesia, lime, alumina, and peroxide of iron.
Dated this 22nd day of Jule 1806
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
I, WALTER ROWBOTHAM, of 27 Vittoria Street, Birmingham, in the County
of Warwick, Electrical 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 has reference more especially to two-fluid primary electric
batteries in which tubular carbon elements and metal elements (such as iron or
zinc) are employed.
According to my present invention I construct the battery with an hermetically
closed outer vessel or casing within which the gas or gases generated during the
working of the battery, are permitted to accumulate under pressure, which pressure
assists in effecting depolarization.
Heretofore when batteries have been constructed with hermetically closed outer
vessels or casings, considerable difficulty has been experienced in constructing
them strong enough to effectually resist the internal pressure arising during the
working of the battery. 1 find that this internal pressure is due to the increase in
the bulk of the liquid in the carbon element cells. This increase in the bulk of
the liquid causes a very great pressure to be exerted within the casing, such
pressure becoming eventually so excessive that the casing, even if made of great
strength, has been unable to resist it without becoming fractured or bursting.
Now according to my invention I construct my improved battery in such a manner

page_text: that this pressure is altogether avoided, so that the casing will not be subjected to
any injurious internal strain from such cause.
A convenient means for avoiding this pressure consists in providing an overflow
or liquid expansion chamber or chambers within the casing so that as the liquid
increases in bulk as above stated ample room will be provided for its reception;
such chamber or chambers being preferably so arranged that the overflow or
surplus liquid is still available for depolarization.
I also provide my improved battery with means whereby the drawing off of
liquid from one of the series of compartments chambers or cells will effect the
emptying of all the other cells and, vice versa, the introduction of fresh liquid into
one of the cells will effect the filling of all the other cells; these means being
such, that during the emptying and filling operations communication is automatically
established between the cells and automatically closed again after an emptying or
filling operation has been completed.
In order that my invention may be clearly understood and readily carried into
effect I will proceed to describe the same with reference to the accompanying
drawings, in which
Figure 1 is a vertical section; Figure 2 a horizontal section and Figure 3 a
transverse section taken on the line 1. 1, shewing my improved electric battery.
Figures 4, 5 and 6 are similar views shewing modified means for automatically
opening and closing communication between the cells during the emptying
operations.
Figure 7 is a sectional elevation and Figure 8 is a longitudinal section taken
through the depolarizing liquid compartments, shewing a further modification of
my invention.
Figure 9 is an enlarged fragmentary section shewing a float valve whose purpose
will be hereinafter described.
Figure 10 is a modification of the arrangement illustrated in Figure 8.
A is the hermetically closed outer vessel or casing of the battery; B is a
partition that divides the said outer vessel into two main compartments a and b,
one of which is further divided by another partition B¹ so as to produce the liquid
expansion chamber c. CC are transverse partitions dividing the main compart-
ments into sub-compartments or cells. D, D are the carbon elements and EE are
the metallic elements, which are preferably of iron or zinc.
The aforesaid carbon elements are preferably in the form of tubes with one end
closed, and are arranged horizontally with their closed ends directed outward.
These tubular carbons are of such a length that their inuer ends extend into the
Partition Bl so that the interior of each of the said tubular carbons is open to the
expansion chamber c. For electrically separating the carbon elements from
the metal elements I employ porous tubes F which surround the tubular carbons
where the latter pass through the compartment a. These porous tubes are open
to the compartment 6 but are closed at their opposite ends, and their diameter is
such that an annular space is left between the exterior of the carbons and the
interior of the porous tubes so that the depolarizing liquid contained in the com
partment can have free access to the interior of the said porous tubes and
completely surround the carbons. The depolarizing liquid I prefer to employ it
this compartment b is a mixture of sulphuric and nitric acids in the proportion
of about 1 part of sulphuric acid to about 1 to 6 parts of nitric acid; the sulphuric
acid being of a strength approximating a specific gravity 1790 and the nitric
acid 1.48. Other depolarizing liquid may however be employed.
In the compartments a wherein the iron or zinc elements are arranged I prefe
to employ a strong solution of sal-ammoniac or nitrate of soda which is wel
known and understood.
a and bare screw plugs for closing the openings through which the aforesai
liquids are poured into the vessel A for charging the battery. D'D' are curren
collecting plates consisting of strips of copper to which the outer ends of th

page_text: ubular carbons are connected. Between the said current collecting plates and
the outer ends of the porous tubes 1 prefer to place some material A that will
act to produce a fluid tight joint and for this purpose I find a mixture of bitumen
and ozokerit advantageous.
The outer ends of the carbon tubes and the current collecting plates are protected
by means of a cover plate A².
When the compartments a and b are charged with their respective exciting and
depolarizing liquids, it will be observed that the interior of the tubular carbons
remains empty, owing to the fact that their open ends communicate with the liquid
expansion chamber c aud this compartment is not charged with liquid. When
however the battery is working the surplus liquid and gases that are generated in
compartment b are enabled to escape through an opening B' at the upper end of
the partition B' and thereby reach and enter the chamber c. During the working
of the battery the bulk of the depolarizing liquid in compartment b gradually
increases and passes through the aforesaid opening B2, into the chamber c.
surplus liquid as it rises in the said chamber c enters the lower tubular carbons,
and thus enables me to further utilize such liquid, so that any depolarizing virtue
it may still possess will be completely used up before it is drawn off from the
battery as spent liquid by the cock at c.
This
In some cases, as for instance when I arrange the expansiou chamber in the
mamer shewn in Figures 7, 8, and 10 the tubular carbons do not extend through
the compartment b, but terminate at the partition B as in Figure 7, so that
their open ends are in communication with the depolarizing liquid in the
compartment b. Instead of employing tubular carbons, I may use carbon rods.
I will now describe the means for enabling the battery liquids to be withdrawn
when spent, referring first to the arrangement illustrated in Figures 1, 2 and 3.
The bottom of the outer vessel A. is tormed with cavities A³ into which the lower
ends of the partitions enter, without however extending completely to the bottom
thereof. Into these cavities I place a substance A that not only has a higher
specific gravity than the battery fluids employed, but is a bad electric conductor,
and is also not materially affected by the fluids. I prefer to use au insoluble
substance such as sand. Assuming the battery to have been filled with the liquids
and the aforesaid substance to have settled at the bottom of the cavities as shewn
in Figure 3, each cell will be isolated from the other by reason of this substance
closing or sealing the openings between the cells, so that one cell cannot short
circuit the other during the working of the battery. Now if it be desired to draw
off the liquids from the battery the cocks a² b and c are opened. The liquid in
the compartments nearest these cocks then commences to flow away and the level
of the liquid falling in such compartments produces a difference in level between
the liquids in these compartments and the contiguous ones. The weight of liquid
acting on the substance A is therefore not equal on both sides of the partition C
and consequently the said substance is displaced from one side of the partition C
to the other, with the result that communication is established between the
contiguous compartments and the liquids they contain flow away from each of
them. A difference in liquid level then occurs between the next contiguous
compartments with the result that the liquids therein also flow away, this difference
in liquid level taking place successively in all the compartments until they are all
emptied of their liquid contente. The said substance A being then no longer
subjected to an unequal pressure resumes its normal position at the bottom of the
cavities by the action of gravity and therefore again isolates one cell from the
other. When the battery is being charged with liquids the aforesaid substance A
acts in analogous manner to open and close the communication between the various
cells.
In Figures 4, 5 and 6 I have shewn a series of passages A which pass from one
side to the other of cach of the partitions C but in this case each of the aforesaid
passages opens on one side of the partitions C into a conical cavity or recess A

page_text: which is provided with a glass or other suitable spherical body A'. This spherical
body or ball acts as a valve which opens only in one direction. When the cocks for
drawing off the liquids are opened the aforesaid balls A' will rise under pressure
due to the inequality of liquid in contiguous cells. After each emptying and filling
operation the said balls resume their closed position under the action of gravity.
In Figures 8 and 9 I have shewn a modification of the automatic emptying and
filling contrivance in which float valves are employed instead of simple balls. In
this case the battery cells are arranged in cascade form (Figure 8) and communi-
cation between the various cells is established by passages or short tubes A³ near
the top of the cells and by passages A' near the bottom of the cells, these last
mentioned passages being provided with downwardly opening valves A10 controlled
by float levers A". A is the filling plug and A13 the emptying tap.
Assume that all the cells or compartments are empty and that a re-charging
operation is to be performed. All the valves A10 will at this time be open owing
to the float-levers being in their lowered position. The fresh liquid is admitted
through the plug A and will rise in the highest compartment until it is able to
escape through the open passage A' into the next compartment where it also rises
until it is able to escape into the next succeeding compartment and so on until the
liquid has risen in all of the compartments to such an extent as to cause the various
float levers to rise and shut the valves A 10. The liquid then continues to rise in
the highest compartment until it reaches the tube A8 through which it flows into
the next compartment and rises therein until it reaches the tube A9 in this
compartment, and so on until all the compartments are charged. In order to
avoid overcharging of the compartments the lowermost one is furnished with a
second tap A. By leaving this tap open during the filling operation it serves to
indicate when all the compartments are sufficiently filled, by allowing the surplus
liquid to flow through it.
It will be observed that this tap A is situated at a comparatively short distance
from the bottom of the lowermost compartment so that the level of liquid in
such compartment rises only a short distance and leaves the upper part of the
compartment empty to serve as the expansion chamber c for all the other
compartments.
To empty the battery of liquid, the tap A¹³ is opened. The liquid in the
lowermost compartment will then escape and when the level of the liquid therein
falls sufficiently to allow the float-valve to descend and open the valve A, the
liquid in the next compartment will flow away through said valve and reach the
outlet tap A13 by passing through the lowermost compartment. As the level of
liquid falls in the various compartments the valves A successively open and thus
permit all the liquid to escape.
Instead of arranging the cells at different levels as shewn in Figure 8 they may
be arranged all on the same level as illustrated in Figure 10 and then the float
levers A would be situated near the top of the cells and be connected to the
valves A by means of connecting rods A15. As the liquid in the expansion
chamber c is at a low level the float lever of the valve in this chamber is situated
near the bottom thereof, as in Figure 8.
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. An electric battery wherein the cells are contained within an hermetically
closed outer vessel which is provided with means for relieving the internal pressure
as the bulk of the liquid in the battery increases, substantially as described.
2. An electric battery provided with means for enabling the cells to automatically
communicate with each other during an emptying or a filling operation and for
automatically closing such communication after the completion of these operations
substantially as described.
3. An electric battery wherein the carbon and metallic elements and cells are so

page_text: arranged and separated from each other that the depolarizing liquid and gases may
be brought into contact with the interior of the carbon elements and so assist the
depolarizing effect substantially as herein described and illustrated.
4. The combination and arrangement of parts comprising the electric battery
substantially as herein before described and illustrated."
Dated this 14th day of November 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.