IM- PROVEMENTS IN FURNACES WHICH ARE PRINCIPALLY APPLICABLE TO THE PROVISIONAL SPECIFICATION
Year: 1863

page_text: LETTERS PATENT to Charles William Siemens, of No. 3, Great George
Street, Westminster, in the County of Middlesex, and Frederick Siemens,
of Birmingham, in the County of Warwick, for the Invention of "IM-
PROVEMENTS IN FURNACES WHICH ARE PRINCIPALLY APPLICABLE TO THE
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
and Frederick Siemens at the Office of the Commissioners of Patents,
with their Petition, on the 18th April 1863.
We CHARLES WILLIAM SIEMENS of No. 3 Great George Street West-
miuster in the County of Middlesex and FREDERICK SIEMENS of Birmingham
in the County of Warwick do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN FURNACES, WHICH ARE PRINCIPALLY APPLICABLE TO
THE SMELTING OF IRON " to be as follows
In smelting iron, the ore and limestone are introduced into the blast furnace
with the addition of such quantities of coke or coal as are found necessary
to effect the reduction of the oxide of iron, to combine with the reduced iron
ore so as to form pig or cast iron, and, furthermore, to generate sufficient heat
(by its combustion) to effect the fusion of the entire mass at the bottom of
the furnace. In order to effect this combustion, large quantities of air are
forced in through the tuyeres at the foot of the furnace, which air is generally
Price 8d.J

page_text: heated to a considerable degree previous to its introduction into the furnace
in order to attain the requisite degree of heat with a reduced expenditure
of fuel.
In producing the coke for blast furnaces, the gases evolved from the
coal are generally allowed to escape freely into the atmosphere, or in some
instances they are partially or wholly burnt in flues surrounding the coke
oven or furnace, to impart heat to the same. The coke is drawn at intervals
from the coke oven or furnace in a state of incandescence, involving a great
loss of heat.
Now our Invention consists in treating coal, for its conversion into coke
and for the production therefrom of combustible gases, by means of furnaces
of such peculiar construction that the separation of the gaseous from the
solid or carbonaceous constituents of the coal is effected in a continuous
manner, without losing either the combustible gases evolved or the heat
residing in the coke while in a state of incandescence.
Our Invention consists further in the employment of the rich com-
bustible gases evolved in the production of coke or in the distillation of
coal for imparting heat to blast furnaces and also for effecting the reduction
of the ore they contain, by forcing these gases into the same through
tuyeres or openings.
The furuace or oven which we employ for effecting the separation of the
combustible gases from the coal consists of a chamber built of firebrick, by
preference of a rectangular sectional form in plan, and of considerable depth.
Two sides of this chamber incline towards each other in ascending and hoppers
or other openings are provided at the top for charging the same with coal. The
bottom of this chamber constitutes a shallow basin which is filled with water,
and suitable openings are provided at the sides (or at one side only) below
the water line for withdrawing the coke withontadmitting air to the chamber.
At the two inclined sides of the chamber passages are formed, communicating
each with a "regenerator" or chamber filled with loosely piled brickwork, the
opposite ends of which "regenerators" are made to communicate, at pleasure,
the one with a channel or flue for conducting the gases away, and the other
with a channel through which atmospheric air, or a mixture of atmospheric air
and water, or of oxygen with or without the admixture of vapour of water, is
introduced. Near the upper extremity ofthe principal chamberanother channel
for the exit of gases is provided. In commencing the operation of coking with
this furnace, it is first filled with coke to the height of the before-mentioned side
pássagescommunicating with the regenerators; fuelin a state of incandescence
is thereupon introduced from above and this is followed up with the coal to

page_text: be converted into coke. The current of air entering through one of the
" regenerators "traverses the ridge of incandescent fuel, thereby supporting
its combustion, and passes away through the second "regenerator" into the
gas channel. When, by the absorption of the heat from the passing currents
of the products of combustion, the second regenerator has become sufficiently
heated, the direction of the currents is reversed by means. of suitable reversing
dampers, and the air now passing through the second regenerator thereby
becomes heated before traversing the ridge of incandescent fuel and thus
causes a great increase of heat in the same. The ridge of fuel being of
considerable thickness, the carbon of the same takes up two equivalents or
atoms of oxygen from the air as it first enters, but the carbonic acid
gas thus
formed, having to penetrate a further mass of incandescent fuel, takes up an
additional atom of carbon and passes away as carbonic oxide; this gas then
passes through the first-named regenerator, which absorbs the heat from the
same and from whence it passes into the general gas flue. If the air is
accompanied by vapour of water, this also becomes transformed, on passing
through the ridge of incandescent fuel, into carbonic oxide and hydrogen. The
carburetted bydrogen and other gases evolved from the fuel by the heat
produced passes partly away with the current of carbonic oxide aud hydrogen
resulting from the combustion and partly ascends through the mass of
superincumbent fuel, passing away through the upper gas channel above
alluded to. This upper gas consists mostly of hydrocarbons, containing also
ammoniacal and other vapours, and may be used either separately from the
gas passing away througn the regenerator, or the two gus channels may
be
connected beyond the regenerators. The upper gas may be purified in the
usual manner and then be used for purposes of illumination; but also the gas
passing away through the regenerator will be possessed of considerable
illuminating power, owing to the presence of a compound of carbonic oxide
and carburetted hydrogen known to chemists by the name of acetelin..
In working the above-described furnace, the direction of the currents of air
and gas has to be reversed at certain intervals (say every hour), fresh coal
has also to be charged frequently at the top, so as to maintain the chamber
nearly filled, and coke may be drawn from the bottom continually or at
frequent intervals. If, however, it should be desired at any time to produce
large quantities of combustible gases without drawing any coke, it will only
be necessary to provide some openings for the entrance of air near the
bottom of the furnace, above the level of the water; this airin passing upwards
through a mass of incandescent coke, will effect the combustion of the same
and pass away through one of the regenerators as carbonic oxide and nitrogen.

page_text: A considerable amount of water will in that case be evaporated from the
bottom, which, in passing also through the mass of incandescent coke, will
be decomposed, forming carbonic oxide and hydrogen.
In order to carry the second part of our Invention into practice, it is not
necessary to alter the construction of the blast furnace in present use. It is
only necessary to provide a pump or other apparatus for drawing the com-
bustible gases from the gas flue of the furnace just described and for forcing
the same into the orifices of the blast furnace through which air alone is now
introduced. Both the air and the gas thus blown together into the furnace
may be heated previously with advantage. The combined currents of air
and combustible gases will, by their combustion, produce intense heat in the
blast furnace and a great saving in coke will be effected in consequence. The
iron produced in the furnace will be of improved quality, owing to the ab-
sence of foreign substances in the gas, which may be purified by the usual
methods if thought desirable.
Inorderto effect a further saving of coke in the blast furnace we sometimes
also effect the reduction of the oxide of iron, either wholly or partially, by the
introduction of gases at a point between the air tuyeres and the top of the
blast furnace. For this purpose special openings or tuyeres will have to be
provided in the sides of the furnace, through which we introduce, by preference
gases particularly rich in carbon and in hydrogen, such as are generated in
the upper portion of the gas and coke furnace above described. The quantity
of gas employed for effecting the reduction of the ore may be varied so as to
produce a higher or less degree of carbonization. By diminishing the reducing
agents, and at the same time increasing the combustion at the lower part of
the furnace,it will be possible to produce even cast steel in the blast furnace.
The gases produced in this coke furnace may be used partly to heat the air
and combustible gases which are forced into the blast.furnace, but the gases
rising from the top of theblast furnace itself maybe employed for this purpose,
and the excess of gases groduced by the gas and coke furnace maybe employed
for other purposes, such as puddling and reheating iron, or for remelting the
same. Or ourimproved gas and coke furnace maybe employed, irrespectively
of smelting operations, simply for producing gas and coke, or gas only for
purposes of heating and lighting generally. In employing the gas for heating
purposes, we prefer to employ regenerative furnaces of the construction
described in the Specification to former Letters Patent granted to us and
bearing date the 22nd day of January 1861, No. 167, for improvements in
furnaces.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles William Siemens and Frederick Siemens in the Great
Seal Patent Office on the 17th October 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we CHARLES
WILLIAM SIEMENS of No. 3 Great George Street Westminster in the County
of Middlesex and FREDERICK SIEMENS of Birmingham in the County of
Warwick send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent bearing date the Eighteenth day of April in the year of our Lord
One thousand eight hundred and sixty-three in the twenty-sixth year of Her
reign did for Herself Her heirs and successors give and grant unto us the
said Charles William Siemens and Frederick Siemens Her special licence that
we the said Charles Willian Siemens and Frederick Siemens our executors
administrators and assigns or such others as we the said Charles William
Siemens and Frederick Siemens our executors administrators and assigns
should at any time agree with and no others from time to time and at all
times thereafter during the term therein expressed should and lawfully might
make use exercise and vend within the United Kingdom of Great Britain
and Ireland the Channel Islands and Isle of Man an Invention for
"IMPROVEMENTS IN FURNACES, WHICH ARE PRINCIPALLY APPLICABLE TO THE SMELTING
OF IRON," upon the condition (amongst others) that we the said Charles William
Siemens and Frederick Siemens our executors or administrators by an
instrument in writing under our or their hands and scals or under the
hand and seal of one of us or them should particularly describe and ascertain
the nature of the said Invention and in what manner the same was to be
performed and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I the said Charles William Siemens on behalf
of myself and the said Frederick Siemens do hereby declare the nature of
the said Invention and in what manner the same is to be perf rmed to
be particularly described and ascertained in and by the following statement
thereof, reference being had to the accompanying Drawing and to the figures
and letters marked thereon that is to say :-
In smelting iron the ore and limestone are introduced into the blast furnace
with the addition of such quantities of coke or coal as are found necessary to
effect-the reduction of the metallic oxide, to combine with the reduced iron

page_text: ore so as to form pig or cast iron, and furthermore, to generate sufficient heat
(by its combustion) to effect the fusion of the entire mass at the bottom of the
furnace.
In order to effect this combustion, large quantities of air are forced in
through the tuyeres at the foot of the furnace, which air is generally heated
to a considerable degree previous to its introduction into the furnace in order
to attain the requisite degree of heat with a reduced expenditure of fuel.
In producing the coke for blast furnaces as well as for other purposes, the
gases evolved from the coal are generally allowed to escape freely into the
atmosphere, or in some instances they are partially or wholly burnt in flues
surrounding the coke oven or furnace to impart heat to the same, and the
coke is generally drawn at intervals from the coke oven or furnace in a state
of incandescence, involving a great loss of heat.
Now our Invention consists in treating coal or other carbonaceous matter
for its conversion into coke or combustible gases, either for heating or for
illuminating purposes, by means of furnaces of such peculiar construction that,
not only is the separation of the gaseous from the solid or carbonaceous con-
stituents of the coal, and, in some cases, the subsequent total conversion of
its carbonaceous constituents into combustible gases, effected in a continuous
manner, without losing either the combustible gases evolved or the heat
residing in the coke while in a state of incandescence, but also, the separation
of the gaseous constituents is effected with such uniformity and at such con-
stant temperature, that the coal or other material operated upon is converted
into gases of considerable heating and even illuminating powers,and into coko
of superior hardness and value to that produced in the ordinary gas retorts
or breeze ovens; in addition to which, substances such as wood, lignite, peat,
and poor coal may also be made available for the production of comparatively
rich combustible and illuminating gases.
Our Invention also consists in so arranging our apparatus that those gases
and vapours which are usually formed when the process of distillation is
carried on at the temperature heretofore employed, such as light carburetted
hydrogen and olefiant gas, the vapour of tar, ammonia, carbonic acid, and
others, become decomposed and reformed under the influence of a white
heat into another class of carburetted hydrogens of great value for illumina-
ting and heating purposes, such as acethylene, propylene, and analogous
compounds.
In carrying the above-described general principles of our Invention into
practice, various modifications in the form and arrangement of the furnace may
be adopted, according to the purposes to which the products are to be applied,

page_text: On the accompanying Drawing are shown those arrangements which we prefer
to employ.
Figures 1, 2 and 3 show an arrangement of our improved furnace in which
the coal or carbonaceous matter is converted into combustible gases and
cokc. Figure 1 shows a sectional elevation on line X X Figure 2,
Figure 2 shows a sectional plan on line Y Y Figure 1; and Figure 3 shows
a section on line Z Z Figure 2; the same letters of reference indicate the
same parts on each of these Figures, as also in the Figures representing
other arrangements.
A is a vertical chamber or retort, built of fire-brick and made of considerable
depth in proportion to its breadth. At the top the chamber is provided with
a hopper B through which the coal or combustible matter employed is intro-
duced at short intervals, and which hopper is closed at the top by means of
the cover C dipping into the trough 6 filled with water, thus forming a
hydraulic joint and preventing the escape of the gases. In order also to pre-
vent the escape of the gases when the cover C is removed for the purpose of
filling in the coal, a valve or flap 1) is provided which is closed when the
cover C is removed and opened when the same is replaced. The sides of the
chamber or retort A are made to widen out somewhat towards the lowerend, so
astofacilitatethegradualpassagedownwardsof thecoalor carbonaceous matter.
At the bottom the chamber or retort is formed into a shallow basin Q contain-
ing water,and an opening is provided at the sidebelow the water line, as shewn,
for withdrawing the coke from time totime without admitting atmospheric air
into the chamber or retort. On each side of the chamber or retort A are
formed two regenerators F F or chambers filled with loosely piled fire-brick
or other refractory materials. These "regenerators" communicate, through a
number of small passages f. f. f', f¹ (which also constitute a part of the
regenerators) and openings a a', with the lower part of the chamber A, and
they are also made to communicate by means of the passages G G and the
reversing damper H alternately with the pipe P for conducting away the
combustible gases and with the external atmospherethrough the pipe O. The
current of the air and gases through the furnace is induced in this case by a
steam jet M, the steam being produced in a series of water pipes m m¹
arranged in the lower part of the regenerators and supplied with water
by a feed apparatus m³ or from an ordinary steam boiler.
Flues I I I I are formed in the end walls of the chainber or retort A,
communicating with the upper part of the latter bymeausof the openings a²a²
for the purpose of conducting away the gases generated in the upper part of
the chamber; these passages IIII are made to communicate by means of

page_text: pipes Jeither with a separate gas pipe K or with the same gas pipe P into
which the lower gases pass.
The action of this furnace takes place in the following manner. In com-
mencing operations, the chamber or retort A is firstly filled with coke to the
height of the openings a, a¹; fuel in a state of incandescence is thereupon
introduced, and upon this is thrown fresh fuel until the chamber is full. A
current of air and steam, induced by the steam jet M or by a jet of air ouly,
or of oxygen with or without steam, now enters, say, through the regenerator F
and, passing down the passages f, f, enters the chamber A through the
openings a, a in a divided current. Here the air and steam are made to
traverse the mass of incandescent fuel towards the apertures a', a', and in doing
so they become converted into carbonic oxide and hydrogen which, if the
temperature be sufficiently high, again combine to form the rich combustible
gases before alluded to.
These pass through the aperatures a a¹ into the
passages ff and down through the regenerator F', imparting to these the
greater portion of their heat and depositing in the same particles of uncom-
bined carbon or soot before entering the gas channel P through the passage G¹
and valve H. By the withdrawal of coke from the bottom,and the introduction
of fresh coal or carbonaceous matter through the hopper B at short intervals,
the coal passes slowly down through the chamber or retort A and fresh
portions of the same arothus continually brought into the intense heat at a a',
whilst the coke or residuum of the carbonaceous matter passes slowly down
into the basin Q, whence it is removed. When the combustible gases have
passed through the passages f¹f, and regenerator F1 for a suflicient length
of time for the same to have become highly heated, the direction of the current
is changed by means of the valve or reversing damper H, and atmospheric
air together with steam now enters the chamber or retort A. through the
regenerator F and passages f¹ f¹, taking up the heat therefrom that has
been previously absorbed from the combustible gases passing through in the
reverse direction, as also burning the soot that was deposited,aud, on traversing
the mass of highly heated fuel, the rich combustible gases that are thereby
formed as before mentioned are now made to pass through the apertures a, a,
passages ff, and regenerator F into the gas pipe P. At the same time, as
the coal or carbonaceous matter in theupper part of the chamber or retort A is
subjected to a less degree of heat than below, the ordinary hydrocarbons and
other vapours are there formed, and if it be desired to employ these gases
separately from the gases formed below, or to mix the same subsequently the
chamber A is provided with the flues I I¹ and apertures a³ a³, as shewn,
through which these upper gases are conducted away into the gas pipes Jand K.

page_text: If however it be desired not to produce any tar or oils, but to convert the
whole of the gases and vapours evolved into the rich combustible gases pro-
duced at a more elevated temperature, then the apertures a³ a³and passages I.I
are dispensed with, and the whole of the gases and vapours formed in the
upper part of the chamber are made to pass down to the apertures a, a².
The coke descending into the water below in a heated condition, causes a
certain evaporation, and the steam so formed, in ascending through the
column of incandescent carbon, is decomposed forming hydrogen and
carbonic oxide, which combustible gases pass away with the rest. If the
heat be carried to whiteness, which is accomplished by withdrawing the coke
slowly, a combination will take place between the carbonic oxide formed
below, and the carburetted hydrogen formed above the exits a, a', and rich
illuminating gases, such as acethylene, propylene and analogus compounds
are produced. If these are intended to be used for purposes of illumination,
the presence of nitrogen should be avoided and pure oxygen and vapour of
water be introduced at M, unless a modification of the apparatus be adopted
which will be described hereafter with reference to Figures 6 and 7.
Instead of discharging the coke into water as described, an arrange-
ment may be applied to the bottom of the chamber, similar to the feed
apparatus at the top, for the coke to be discharged into, having a valve or
slide for cutting off the communication with the chamber and a door for
letting out the coke.
Figures 4 and 5 show, respectively, a sectional elevation on line V V and
a sectional plan on line W W of an arrangement of our furnace in which
the whole of the coal or carbonaceous matter is converted into combustible
gases. For this purpose, instead of the chamber or retort A being formed at
bottom into a basin containing water, a step- or other grating E is there
provided for the admission of atmospheric air, which, in passing up through
the incandescent coke, converts the whole of the carbonaceous matter into
carbouic oxide, which, as it passes into the intense heat at a a', again becomes
partially decomposed as before described. Steam is also introduced at the
bottom through the pipe N, which steam becomes decomposed as it passes up,
into carbonic oxide and hydrogen. The regenerators F F are in this
instance formed at the back of the chamber or retort A and communicate
with the same through the passages GG, ff, and apertures a a'. M is,
as before, a jet of steam or atmospheric air that is made to pass into the
furnace through the pipe O for the purpose of inducing a current through the
same, and if steam be employed, this will become decomposed in the chamber
A and will combine with the other gases as before described with referenco

page_text: to the first arrangement. If it be desired to produce particularly pure gases
rich in acethylene, propylene, and analogous compounds, for illuminating
purposes, steam alone may be introduced into the furnace through the pipeO,
and instead of admitting atmospheric air at the bottom of the chamber, a jet
of oxygen only may be there introduced, whereby the absence of nitrogen in
the combustible gases will be insured, and the requisite white heat obtained.
The hydrocarbons formed in the upper part of the chamber may, as in the
first-described arrangement.be either conducted away through apertures aa²,
passages II, and pipes J and K, and used separately from the other gases
or mixed with them subsequently, or they may be made to pass down into
the intense heat at a a' where they are decomposed and combine with the
other gases as before described. L L' are sight holes, closed as shewn,
(and which may also be employed in the first-described arrangement)
for observing the temperature of the furnace and for removing any
obstructions that may form in the apertures a¹. The earthy residuum,
that falls below the grate E after all carbonaceous matter is extracted, is
removed thence from time to time. The other parts of the furnace are
precisely the same as in the first-described arrangement, as is also the manner
of working the same, and no further description is therefore required.
Figures 6 and 7 show respectively a sectional elevation on line T T and a
sectional plan on line UU of another arrangement of our furnace, in which
the rich illuminating gases above referred to are produced, to the exclusion of
nitrogen without having recourse to the introduction of oxygen gas. In
this case, instead of highly heated atmospheric air or pure oxygen being
introduced into the chambers or retorts A A¹ and producing tho requisite
intense heat by combining with the coal or carbonaceous material to be
converted, the requisite heat is generated by the combustion of highly heated
atmospheric air with combustiblo gasin spaces or passages formed outside the
chambers or retorts A A'. For this purpose combustible gas, produced either
in the furnace itself or in a separate generator, is conducted through the flue S
and passages s. s¹ into spaces T T that are formed beneath each of the gas
passages I I I I¹ outside the chambers A. A'. These spaces T T com-
municate by means of connecting passages a, a, a, a respectively with all
the small passages or flues f³ and f4, f¹ and f, that conduct the highly heated
atmospheric air down from the top of the regenerators F1 F2 F3, and thus
the combustible gases meeting with the highly heated atmospheric air in the
spaces TT' and passages f¹, f³, fs,f4, enter into combustion with the same,
producing intense white heat, which is consequently imparted to the chambers
A A' and to the coal or carbonaceous matter contained therein.
The

page_text: relative action of the regenerators F¹ F3 F3, for effecting the alternate
absorption of heat from the products of this combustion and the imparting of
such heat to the atmospheric air as it passes through them, takes place in the
following mauner. According to the position of the reversing valve or
damper H, atmospheric air is caused to pass, say, through the flues G¹ G³
and into the spaces g' g³ at the bottom of the regenerators F¹ F3 which
have previously absorbed the heat from the products of combustion; on
passing up through the same, the air arrives in a highly heated state at the
passages f, f, and is conducted down through them into the spaces T T".
Here, as before mentioned, the air meets with the combustible gases coming
from the flue S and enters into combustion with the same; the highly heated
products of this combustion then pass up through the passages fa and f3 and
into the regenerator F2, through which they pass in a downward direction,
imparting to the same the greater portion of their heat and finally escaping
through the passage g² into the flue Y of the chimney. When, by the passage
of the products of combustion, the regenerator F" has become highly heated,
the position of the reversing valve H is changed and the atmospheric air is
now made to enter through this regeneratorwhilst the products of combustion
pass away through the regenerators F¹ F³.
On commencing operations with this furnace, the ignition of the mixture
of air and combustible gases in the spaces T T" is effected through the sight
holes L L' which are then closed as shewn. In some cases, and particularly
where a portion of the gases p:oduced in the furnace are employed to produce
the requisite heat, instead of or besides introducing the combustible gas
through the passages S 8, s we conduct the same through channels c¹, c²,
c3, cand apertures d³ into the passages f¹f f3f4, where it
enters into combustion with the atmospheric air immediately as it issues from
the regenerators, and thus produces a more uniform heat in the chambers
A A than when the gas is intro luced through the passages Ss 9. The
passage of the gas through the channels c', c2, cs, es, must be regulated by a
valve in a corresponding manner to the passage of the air through the
regenerators, that is, at one time it must pass in through the channels c¹, c
and at another time through the channels c², c³. The combustible gases
produced at a white heat in the chambers or retorts A A¹, will on account
of their being no air introduced, be free from nitrogen and will be of great
illuminating power on account of their richness in acethylene, propylene, and
analogous compounds. The gases formel in the upper part of the chambers
or retorts are made to pass down into the lower part and are likewise cou-
verted, the whole of these gases passing through the apertures a, a, u², a' at

page_text: bottom, into the gas flues I I II whence they are drawn through the
pipes J J and K into the gas propeller and washer %, through which they
are made to pass in a downward direction by a shower of water falling from
the top, the water being introduced through a pipes and perforated plate z¹.
From the bottom of this propeller the gas passes into the lime purifier W or
other apparatus employed for purifying gases and thence into a gas holder.
The gas passages I I I I may be cleansed from soot by the introduction
of air into them from the top or sides at any time. As in the first described
arrangement, the coke passes from the chambers A' A' into receptacles or
basins QQcontaining water, whence it is removed from time to time below
the surface of the water.
The coke which is produced byour improved furnaces is of superior quality
and hardness, and is particularly applicable for use in blast furnaces for
reducing metallic ores.
We also employ the combustible gases coming from
the furnace for the same purpose by forcing them by means of a pump or
other apparatus through tuyeres into the blast furnace, where, on entering into
combustion with the air blast (both having been by preference previously
heated) they create an intense heat and effect a great saving of coke, in
addition to which, the metal produced in the furnace will be of an improved
quality, owing to the absence of foreign substances in the gas, which may be
purified by the usual methods if thought desirable or simply washed, as before
described with reference to Figures 6 and 7, by being passed down through
a vertical tube through which a shower of water is mado to fall, and the
propelling force of which may be made use of, in conjunction with the action
of the air blast, to force the gas into the blast furnace instead of using pumps
or fans for that purpose.
In order to effect a further saving of coke in the blast furnace, we some-
times also effect the reduction of the oxide of iron either wholly or partially
by the introduction of gasses at a point between the air tuyeres and the top of
the blast furnace. For this purpose special openings or tuyeres will have to
be provided in the sides of the furnace, through which we introduce, by
preference, gases particularly rich in carbon and hydrogen, such as are
generated in theapparatus before described. The variety of furnace described
with reference to Figures 4 and 5, for producing no coke but only gas, will
be more particularly applicable under these circumstances. The relative
quantity and quality of gas employed for effecting the reduction of the ore
may be varied, so as to produce a higher or less degree of carbonization. By
diminishing the reducing agents and at the same time increasing the com-
bustion at the lower part of the furnace,. it will be possible to produce even
.

page_text: cast steel in the blast furnace. The gases produced in the coke furnace may
be used partly to heat the air and combustible gases which are forced into
the blast furnace, but the gases gases rising from the top of the blast furnace
itself may be employed for this purpose, and the excess of gases produced by
the gas and coke furnace may be employed for other purposes, such as for
puddling and reheating iron.
In employing the gas for heating purposes, we prefer to employ regene-
rative furnaces of the construction described in the Specifications to former
Letters Patent granted to us and bearing date respectively the 2nd De-
cember 1856 (No. 2861) the 11th May 1857 (No 132) and the 22nd
January 1861 (No. 167). Irrespective of the above-mentioned application
of the gases produced in our improved furnace, they may with advantage be
employed for lighting towns, for which purpose in some cases their illuminating
powers may be increased by being passed through or in contact with naptha
or other liquid hydrocarbons, and also when the gases produced are specially
adapted for heating purposes only, these may be conveyed into towns through
mains in the same manner as illuminating gases, to be there employed in place
of solid fuel.
Having now described the nature of our Invention and the best means we
are acquainted with of performing the same, We wish it to be understood that
we do not limit ourselves to the precise arrangements and details of our
improved furnaces as herein-before described with reference to the accom
panying Drawing, as these may Le variously modified without departing from
the nature of our invention; thus, although we much prefer to make use of
regenerators for producing the intense heat required, yet heating apparatus
of different construction may be applied, and the form and construction of the
heated chambers, as well as the means adopted for charging and discharging
them, may be greatly modified; also, the chambers or retorts may be arranged
in a somewhat inclined position instead of being placed vertical. l'urthermore,
we wish it to be understood that we do not claim generally the use of vertical
chambers or retorts for making gas and coke which are charged at the top
and discharged at the bottom, nor do we claim, except in combination as
before described, the discharging of the coke into water after the gases have
been separated therefrom, nor the application of regenerators to the heating
of fgas retorts, nor do we claim generally the application of combustible gases
to the smelting of iron and other ores, as we are well aware that such arrange-
ments have been already proposed or employed but what we claim is
Firstly. Constructing furnaces in which coal or other carbonaceous material
is subjected, whilst descending gradually in upright recipients or retorts, tothe

page_text: action of intense heat resulting from the application of regenerators with
reversal of currents, the result being either the total conversion of the carbon-
aceous matter into combustible gases when a grate is applied at the bottom
of such recipients, or the production of both combustible gases, and coke
of superior quality when admission of atmospheric air to the bottom of the
recipient is prevented.
Secondly. Arranging and heating upright chambers or retorts in such a
manner that highly illuminating gases, such as acethylene, propylene, and
analogous compounds, are formed by the union at a white heat of the necessary
constituents for the production of these gases, such constituents being the
first results of the decomposition and partial co:nbustion of the carbonaceous
material gradually descending in the said chambers or retorts.
Thirdly. Constructing furnaces for effecting the production of combustible
gases and coke from coal or other carbonaceous matter in such a manner that
the gases issuing from the incandescent mass near the lower extremity of an
upright chamber or retort, containing such material, deposits its heat and
also soot in a regenerator, which heat is subsequentiy imparted to a current
of air with or without the admixture of steam, which, in traversing the same
regenerator in the reverse direction, burns the soot there deposited, and
after having, in traversing the mass of incandescent fuel, being converted into
a combustible gas,imparts heat as well as a certain deposit of soot to a second
regenerator, until the direction of the current is again reversed, the column of
fuel being replenished continuously or from time to time through a feed
apparatus at the upper extremity, and the coke withdrawn from side openings
below water at the lower extremity, substantially as herein-before described
with reference to Figures 1. to 3 on the accompanying Drawing.
Fourthly. The same combination of regenerators with an upright recipient
in which coal gradually descends as described in the third claim, with the
substitution of a grate for the water tank at the bottom of the apparatus, for
the purpose of effecting the entire conversion of the carbonaceous material
into combustiblo gases, substantially as herein-before described with reference
to Figures 4 and 5 on the accompanying Drawing.
Fifthly. o combining coke and gas ovens, of the construction as herein-
before described, with blast- or other furnaces for the reduction of metallic
ores, that while the whole or part of the coke produced is charged with the
ores to effect their reduction, the gases or a portion of the same (being by
preference washed and heated on their way) are forced into the same blast-
or other furnaces together with atmospheric air (also by preference previously
heated) to effect their combustion, in order to generate the heat necessary to

page_text: complete the operation of the blast- or other furnace, the object being
economy of fuel and greater freedom from sulphur and other impurities of
the metals produced.
In witness whereof I the said Charles William Siemens have hereunto
set my hand and seal this Seventeenth day of October in the year of
our Lord One thousand eight hundred and sixty-three.
Witness
C. D. ABEL,
20 Southampton Buildings.
ذ
L.S.)