Improvements connected with Electric Batteries.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements connected with Electric Batteries.
WILLIAM STEPNEY RAWSON, of 21, Greycoat Gardens, London, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to that class of electric battery in which electricity is
obtained by the oxidizing action of a fused salt upon a molten metal or alloy
through the interstices of a porous pot or diaphragm such oxidized metal or alloy
being afterwards reduced by means of carbon or hydro carbon or other reducing
agent, and the salt being recuperated by the action of oxygen or air forced into
it. In order that the chemica! actions may take place the metal or alloy as
well as the fused salts must be kept at a high temperature. When lead is used
this temperature is about 1800° F.
Hitherto this has been effected by putting the lead into a cast iron vessel to
which heat is applied from outside. Such a method is very wasteful of heat and
it is very difficult to regulate the supply so as to keep the temperature within
the limits required by the nature of the salts.
My invention bas for its objects the economical production and retention as
well as the easy regulation of the heat required and also the replacing of the iron
vessel by materials which are permanent at such high temperatures.
To carry this out I construct a chamber of bricks, preferably of magnesia (free
from silica when lead is to be used) and I lay this in any of the well known ways
such as by an outer wall having a closed air space between it & the chamber.
The chamber is provided with a port or ports through which producer gas coal
gas petroleum hydrocarbons or carbon may be introduced.
Through this port or ports may also be introduced a supply of oxygen in some
form, such as air or steam, which combining with the carbon or hydrogen. may
produce heat to maintain the desired temperature in the molten lead or other
metal or alloy through which they are forced at a suitable pressure. Suitable
baffles may be arranged in the interior of the chamber. An outlet pipe is pro-
vided in the closed well-lagged cover of the chamber for the products of com-
bustion. The porous pot or pots which are preferably of magnesia are closed
tightly with a cover through which pass an inlet & outlet pipe for the supply &
egress of air, the former pipe dipping to the bottom of the pot which contains the
fuseu salt and serving as one electrode of the cell and the latter pipe being above
the surface of the salt. The pot or pots are suitably kept in position on the
floor of the chamber which is perforated to allow the air pipes to pass through
and also the lugs of the metal plates which serve as the electrodes in the lead.
Both the plates and the air pipes may be covered above the surface of the
liquids by a suitable adhesive fireproof cement to prevent oxidation. The per-
forations in the covers are also tightly packed with a heat resisting cement. To
start the cell blow pipes may be introduced at the ports or other openings for the
purpose and the walls of the chamber and porous pots thus raised to a suitable
temperature, the molten metal or alloy is then poured in to the required height

page_text: and a supply of producer gas coal gas petroleum or hydrocarbon together with
oxygen in some form is passed through the port or ports and the molten metal
or alloy to raise the temperature of the interior to the required point. Finally
the requisite amount of salts is introduced through the exit pipe of the porous
pot or pots.
It is understood that for the continuous production of electricity in the cell
carbon or hydrocarbon in some form must be supplied in the outer chamber to
reduce the oxide and air must be supplied to the salts to prevent them being
reduced.
The amount of heat produced in the outer chamber may be regulated by the
amount of oxygen supplied with the carbon or hydrocarbon.
As however such a type of cell may produce by its internal actions when giving
current an amount of heat which may raise the temperature of the salts above
the desired point I arrange in connection with the outlet pipe of the porous pot
an apparatus such as a flexible metallic air vessel which by the expansion of
the air shall actuate the valve of the air inlet of the porous pot and allow more
air to pass into the salts to cool them whenever the temperature tends to exceed
the desired point. The heat of the products from the porous pot and the outer
chamber may be utilized to provide power to drive the air pump.
A battery of such cells may be arranged side by side & end to end so that the
heat lost by radiation is reduced to a comparatively small amount.
Dated this
day of November 1898
I, WILLIAM STEPNEY RAWSON, of 21, Greycoat Gardens, London, 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 invention relates to voltaic batteries of that class in which electricity is
generated by the oxidising action of a fused salt upon a molten metal or alloy
separated from it by a porous pot or diaphragm, such oxidised metal or alloy
being continuously or intermittently reduced by means of carbonaceous gas or
vapour and the salt being recuperated by the action of oxygen or air forced into
it.
In order that the chemical actions may take place the metal or alloy must be
kept at a high temperature. When lead is used this temperature is as high as
1850° F.
Hitherto this temperature has been maintained by applying external heat to
a metal vessel containing the molten metal. Such a method is very wasteful of
heat and has other drawbacks, one of which is the difficulty of regulating the heat
so as to keep the temperature within the limits required by the nature of the
salts.
This invention has for its object the economical production and retention as
well as the easy regulation of the heat required and in addition the dealing with
the products of combustion so as to economically utilise the heat which they
contain when they issue from the apparatus. For the purpose of retaining the
heat or in other words to check radiation, the cell is preferably constructed of
magnesia bricks free from silica when lead is used and it is lagged in any of the
well known ways. The cell is provided with a port through which combustible

page_text: gas such as water gas, coal gas, producer gas, petroleum or other carbonaceous
gas or vapour is introduced under pressure.
Through this port may also be introduced under pressure a supply of oxygen
or compounds containing oxygen such as air or steam which combining with the
combustible material produces in the molten metal or alloy the necessary heat
to maintain the temperature.
It has been found by experiment that in the case of easily oxidisable metals
such as are suitable for batteries of this type the combustion is perfect so that
the units of heat produced can be exactly regulated by the amount of air forced
through, the combustible material being always somewhat in excess to prevent
oxidation of the metal. In the closed cover of the cell an outlet pipe is provided
for the products of combustion.
The porous pot which is preferably of magnesia is closed tightly with a cover
through which pass an inlet and an outlet pipe for air. The inlet pipe dips to
the bottom of the porous pot which contains the fused salt and the outlet pipe
starts above the level of the fused salt.
The porous pot is suitably kept in position on the bottom of the cell and is
kept from rising out of the molten lead by the cover of the cell which is perforated
to allow the air pipes to pass through it.
The inlet pipe preferably extends horizontally along the porous pot and is
perforated with holes to subdivide the air streams; the part of the pipe above
the salt may be coated with protecting material. It may be employed as one
electrode of the cell. The other electrode is a cast iron plate immersed in the
lead. The molten metal may be introduced after the walls of the cell and the
porous pot have been sufficiently heated by a blow-pipe or other means and then
a supply of combustible gas or vapour is passed through the metal under pressure
together with the amount of air necessary to maintain the temperature.
During the working of the cell air is blown through the molten salt and com-
bustible gas or vapour is blown through the lead. As the action of the cell is
such as to produce a certain amount of heat by the reduction of the metallic oxide
the temperature may rise beyond the desirable point. In this case an excess of
air beyond that actually required to regenerate the salt is forced in so as to cool
the salt.
As both the combustible gas and the air must be supplied in proportion to the
out-put of the cell, the pumps which supply them under pressure may con-
veniently be driven by an electric motor through the armature of which the
current of the cell or a fraction thereof passes so that the speed of the pump may
vary directly with the output of the cell. The heated products from the porous
pot and from the molten metal may be applied to heat the entering air.
But I prefer to deal with the products from the molten metal as follows:-
Taking the case of water gas as the combustible employed; this as is well
known contains hydrogen carbonic oxide and a small amount of nitrogen. After
passing through the molten lead the products would be carbon dioxide steam and
nitrogen. I take part of these products to the gas generator and pass them over
the red hot coke, instead of the steam which is generally employed, the carbon
dioxide is thus converted into carbon mon-oxide and the steam is decomposed
to hydrogen and oxygen which latter taking up carbon produces carbon mon-
oxide.
The advantage gained by this method is that the cost of raising steam is saved
and the heat of the products of combustion from the molten lead is fully
utilised.
When a group of cells are electrically connected they may conveniently be
separated by partitions in one structure so that the loss of heat by radiation is
reduced to a minimum.
As at least half the volume of combustion products has to be discharged it is
convenient to connect the first, third and other odd cells to the generator and
the second, fourth and other even cells to a chimney, suitable valves or dampers
being provided for alternating or connecting the flues as may be desired.

page_text: J
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. In a voltaic battery operating with fused materials the herein described
method of heating the materials by introducing combustible gas or vapour, with
a regulated quantity of oxygen and effecting-combustion-within-the-cell.-
2. Working the compressing pumps by an electric motor, supplied with current
from the cell; substantially as and for the purpose set forth.
Dated this 18th day of September 1899.