IMPROVEMENTS IN THE MEANS AND APPARATUS FOR PRODUCING OXYGEN, AND IN THE APPLICATION OF THE SAME FOR METALLURGICAL AND OTHER PURPOSES
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office of the
Commissioners of Patents, with his Petition, on the 28th February 1867.
-A communication from abroad by Henri Adolphe Archereau, Chemist,
of 29, Boulevart St. Martin, Paris.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE MEANS AND APPARATUS FOR PRODUCING OXYGEN,
AND IN THE APPLICATION OF THE SAME FOR METALLURGICAL AND OTHER PURPOSES,"
to be as follows:-
This Invention relates, 1st, to the production of oxygen by the decomposition
of sulphuric acid by heat; 2ndly, to condensing oxygen gas and applying it to
various purposes, more especially in metallurgical operations. I will proceed
to describe each part of the Invention separately.
Sulphuric acid of commerce, whether concentrated or non-concentrated;
when raised to a certain temperature becomes decomposed into steam, oxygen,
and sulphurous acid, and this decomposition of sulphuric acid in apparatus of
this Invention forms the first part of the improvements.
The operation is effected by means of the following apparatus:-1st, the
producer or apparatus in which the sulphuric acid is decomposed at a high
temperature; 2ndly, the condenser or apparatus serving to condense and
collect the steam and sulphuric acid vapors which have escaped decomposition;
3rdly, the washer for dissolving the sulphurous acid by setting the oxygen at
liberty, which passes away to a gasholder; this washer may be dispensed with,

page_text: in which case the oxygen and sulphurous acid would pass direct to the gas-
holder, whence they are withdrawn for the purpose of condensation, the
separation of the two gases being produced by the pressure determining the
liquefaction of the sulphurous acid only, which flows out at a discharge cock
placed at the lower part of the compressing cylinders; the oxygen is then
slightly washed in order to deprive it of any remaining sulphurous acid. The
condensed sulphurous acid is placed in communication with leaden chambers
or other apparatus, in which it is transformed into sulphuric acid to be employed
afresh for the manufacture of oxygen in apparatus suited to the production of
this gas. The condensing and washing apparatus above referred to being well
known I make no claim to them except in combination with the principal
apparatus or producer. The producer serving to decompose the sulphuric
acid consists of a furnace or other heating chamber provided with a cylinder
or cupola of refractory material, coated externally with lead, which is further
encased in strong metal. Other substances not liable to be acted on by the
sulphuric acid may be substituted for the lead, such as granite, porphyry, lava,
india-rubber, or gutta percha. The lead casing is not, perhaps, absolutely
necessary; it is, however, preferable to employ it as it prevents the possible
production of hydrogen by contact of the acid with the metal sides, which are
liable to decompose the water, as iron for example; the lining thus serves to
prevent explosions resulting from a mixture of oxygen and hydrogen. In the
cylinder or cupola of refractory materials are placed heavy materials serving
as good conductors of heat, such as cast iron, for example, and suitable for
absorbing all the heat developed, with the object of storing a large amount in
the apparatus at a sufficient temperature for readily decomposing the sulphuric
acid. At the lower part of the furnace, around its circumference, are disposed
two annular pipes, one of which is in communication with a supply of com-
pressed air; on each of these annular pipes are branch pipes in pairs for the
passage of the gas and compressed air, which unite before arriving at the
cupola for the purpose of commingling the gas and air, and which by their
union form so many blow pipes or burners developing sufficient heat in the
cupola for effecting the reduction of the matters; this mode of heating may
be replaced by any other; for example, I may utilize the heat from the gases
of blast furnaces or employ inflammable gases or liquids for the purpose, or
I might in case of necessity employ solid fuel by adapting a closed fire-box to
the bottom part of the apparatus in which would be placed a movable furnace
to be withdrawn when the apparatus is sufficiently heated, the fire-box being
then closed, and the liquid to be decomposed introduced. The upper part of
the apparatus is hermetically closed, preferably by an hydraulic joint, with a

page_text: view to prevent any escape of the decomposed gas; this hydraulic joint may
by the aid of a counterbalance weight be raised or lowered when the apparatus
is in or out of action; it is also covered with water at top to prevent the
fusion of the lead. When the furnace is heated, and before the introduction
of the sulphuric acid, the hydraulic closure is raised, and a chimney of sheet
iron is substituted for carrying off the products of combustion and increasing
the draught. When the temperature of the furnace has reached the desired
point the hydraulic closure is lowered, after which a jet of steam is injected
into the apparatus in order to cleanse it and drive out all the gases of com-
bustion, which pass off by a purge cock fitted to the closure described; a
proportion of sulphuric acid is then introduced into the cupola by the aid of a
funnel, which acid becomes decomposed into oxygen, steam, and sulphurous
acid; these several products of the decomposition pass from the producer to
the condenser, in which apparatus they pass through a worm tube kept
constantly cooled; by this means the steam and vapours of sulphuric acid which
may have escaped decomposition will become condensed; and may be collected
at the lower part; thus the condenser is intended to eliminate the sulphuric
acid diluted in water escaping decomposition in the first apparatus, and to set
at liberty the oxygen, gas, and sulphurous acid, which pass thence to the
washer. This latter apparatus is filled with lumps of coke or other solid
matters, a rose head at top keeping up a constant supply of water in the form
of fine rain for the purpose of dissolving the sulphurous acid gas, and thus
setting the oxygen at liberty, which is then conveyed to a gasholder.
The dissolved sulphurous acid diluted in water, as before alluded to, collects at
the lower part of the apparatus, to be conveyed thence to any suitable point.
Oxygen gas thus produced and stored I employ for various purposes,
especially in metallurgical operations, for heating cupolas and otherwise, and
these applications and the means employed therefor constitute the second part
of this Invention. In order to obtain the greatest useful effect from oxygen
injected under the fire in a furnace used for metallurgical operations or other-
wise, I commence by condensing the gas in some cases to as high a pressure
as ten atmospheres in cylinders of sufficient strength to resist such pressure.
The gas so compressed, if injected under a cupola furnace, for example,
creates a temperature sufficient to melt any materials contained, but which
the apparatus itself could not withstand. were the operation to be of long
duration; but, as the operation requires but a short time from the rapidity
with which the oxygen is injected, I am by these improvements enabled, 1st,
to produce a very high temperature throughout the area of the furnace; 2ndly,
to employ cupolas of refractory clay lined with a still more refractory material.

page_text: The metals to be melted placed in the cupola, being good conductors, and
absorbing all the caloric developed, become so quickly liquefied and melted
that the materials of which the cupola is constructed being themselves but
indifferent conductors, have insufficient time to become fused, while the inner
lining being of a moré refractory nature is alone subjected to the greatest heat,
and the only repairs necessary after each operation would be to reline the
cupola with such highly refractory material; this is a plaster composed of
pounded Paris anthracite or other coal, or it may be a plaster having for its
base lime and magnesia instead of coal. Sometimes I make a plaster of a
mixture of the above-mentioned substances, but in all cases combine them
together with rosin, pitch, or tar; this inner lining is ordinarily hardened or
baked by the small fire in the cupola. This lining should be always sufficiently
hard at the time of introducing the oxygen for it to be perfectly so before the
fusion of the metal is terminated. 3rdly, iron is melted and liquefied in this
manner too quickly to become carburetted, thus avoiding the production of
cast iron. Charcoal is the best fuel to use when melting iron in the manu-
facture of steel. The iron. being thus melted, I may, while it is liquid, either
run it into moulds like cast iron, instead of transforming it into steel by the
addition of a certain quantity of cast-iron infusion, or producing a reaction in
the cyanides.
In order to render the Invention more clearly understood I have in the
accompanying Drawings represented the several apparatus employed in the
production of oxygen.
Figure 1 shows a central vertical section of the producing apparatus for
decomposing the sulphuric acid, the section being taken on the line 3, 4,
Figure 5; Figure 2 is a vertical section of the refrigerator or cooler; Figure 3
is a vertical section of the washing apparatus; Figure 4 is a central vertical
section of the decomposing apparatus on the linė 5, 6, Figure 5; Figure 5 is
a horizontal section of the same on the line 1, 2, Figure 1; lastly, Figures 6
and 7 show a vertical section and plan of a cupola. The same letters serve
for all the Figures.
a, furnace or cupola of refractory material forming the decomposing
apparatus completely encased in lead b, and an outer casing 6'; at the lower
part of the apparatus are disposed two annular pipes c, d, the one c of which
receives gaseous oxide of carbon or other inflammable gases from a pipe f, and
distributes it by pipes g to the tuyères h, the other ring d receives compressed
air from a pipe i, which is also distributed by means of pipes to the blow-
pipes h. The apparatus may be provided with a draught chimney, or it may
in itself be of sufficient height to produce a draught, and so dispense with the

page_text: compressed air. The upper part of each tuyère his furnished with a hollow
perforated cap, whereby air is introduced for quickening the draft of compressed
air passing into the apparatus; h', cocks mounted on tuyerès h between them
and the apparatus for producing the oxygen; these cocks are closed during
the decomposition of the sulphuric acid, and are open only at the time of
heating. The above-described mode of heating by gas is the one most con-
venient for carrying out the operation, but other means of heating may be
employed, such as by employing the waste gases of furnaces or fuel of any
kind.
a
At the upper part of the apparatus is an annular channel k filled with water,
forming an hydraulic joint to the furnace; 1, metal chimney, shown in red lines,
fitting on the cupola a when the hydraulic joint is raised and the heating
commences, and serving to carry off the products of combustion and increase
the draught; m, cover or hydraulic closure rising and falling by the aid of a
counterbalance weight n; o, purge cock; p, cock for the discharge of the
gases produced by the decomposition of the suphuric acid; these gases being
conveyed to the condenser by pipe q, which latter is removed before rising
the hydraulic cover m; r, funnel by which the sulphuric acid is introduced
at any suitable point of the apparatus. The sulphuric acid becomes decom-
posed by contact with the heavy matters s placed in the cupola a, and which,
being good conductors, give off the heat they have previously absorbed ;
t, worm tube of condenser kept constantly cool, which condenses the steam,
and causes the sulphuric acid diluted with water to collect at the bottom of
the apparatus. The oxygen and sulphurous acid pass by means of a pipe ti
to the washer represented in Figure 3, and which is filled with coke or other
solid body not liable to be acted on by the matters; u, rose head supplying
water in the form of rain to dissolve the sulphurous acid gas, a solution of
sulphurous acid in water being collected at the bottom of the apparatus or
of water charged with sulphuric acid. The oxygen gas thus separated is
conveyed by a pipe v to a gasholder; x, reservoir of water for supplying the
washer and condenser, which water may be alkalinized, if desired, in order
that the effect of the absorption of the gaseous sulphurous acid may be rendered
as complete as possible. After the oxygen gas is stored it is highly compressed
in metal cylinders, and then distributed for use either for heating cupolas in
the manner herein described, or otherwise; y, cupola pivotted at 2, 2, made
of refractory clay, and lined with a more highly refractory material 1 for
receiving the full force of the heat; z, pipe for introducing the jet of oxygen
gas; 3, 3, tuyères provided with cocks for the introduction of compressed air ;
oxygenated air or oxygen alone may be introduced. The sulphuric acid may

page_text: be introduced into the oxygen gas generator in a liquid state, either hot or
cold, or it may be in the state of vapor. Where two generating apparatus are
employed the waste heat from the one may serve to beat the sulphuric acid to
be introduced into the other. I employ, by preference, a platina pipe for
introducing the acid to be decomposed. I have in this Specification described
methods of producing and applying oxygen, but it is equally applicable for the
production of protoxide of azote, which in its nature and properties closely
resembles oxygen; this gas may be produced in the apparatus before described
by injecting therein, for example, nitrate of ammonia dissolved in a small
quantity of water. Protoxide of azote thus produced may be applied to the
same purposes, and in a similar manner to the oxygen. Although I have
mentioned charcoal as being used for heating the cupolas, I may heat them by
the aid of inflammable gases, either alone or in combination with charcoal.
The Invention thus consists, 1st, in the method of decomposing sulphuric
acid of various degrees of strength for the purpose of obtaining oxygen there-
from; 2ndly, the apparatus herein described and represented in the Drawings,
more particularly the apparatus for decomposing the sulphuric acid, whatever
may be the method of heating employed; 3rdly, the mode of compressing
oxygen gas in order to its better utilization; 4thly, the use and application
of oxygen so condensed to various purposes, but especially in metallurgical
operations, as in the manufacture of iron and for the production of extremely
high temperatures, so as to admit of the hardest matters being melted without
fusing their containing apparatus; 5thly, the mode of fusing iron without its
being carburetted, that is to say, without any production of cast iron, as
described.