IMPROVE- MENTS IN APPARATUS FOR THE PRODUCTION, PURIFICATION, AND COMBUSTION OF GASES FOR HEATING PURPOSES."
Year: 1864

page_text: LETTERS PATENT to Charles William Siemens, of No. 3, Great George Street,
Westminster, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR THE PRODUCTION, PURIFICATION, AND COMBUSTION
OF GASES FOR HEATING PURPOSES."
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents, with his Petition, on the
3rd December 1864.
I, CHARLES WILLIAM SIEMENS of No. 3 Great George Street, Westminster
in the County of Middlesex do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN APPARATUS FOR THE PRODUCTION, PURIFICATION, AND
COMBUSTION OF GASES FOR HEATING PURPOSES" to be as follows
These improvements relate to the construction of apparatus for converting
carbonaceous matter into combustible gases, for purifying such gases, and for their
application to the heating or fusing of metals and other substances. In order to
convert carbonaceous, matter, such as coal, peat, or wood, into a combustible gas,
I adopt such an arrangement of apparatus that the fuel descends gradually through
one or more vertical or inclined retorts formed of cast iron, fire-brick, or other
suitable material, and is made to pass from the lower end of such retort or retorts
upon the fire-grate, or an inclined plate with openings for the admission of
atmospheric air. At this point combustion ensues, but the mass of fuel acted upon
being large, each particle of oxygen which enters will take up two particles or
equivalents of carbon, and produce carbonic oxide, which is a combustible gas
The carbonic oxide gas thus formed, together with its necessary admixture of
nitrogen, is conducted upwards and over or around the external surfaces of the
retort or retorts through which the solid fuel descends, in order to impart its free
heat to the same before passing away to the furnace where it is to be consumed
The heat thus communicated to the descending column or columns of fuel serve
to effect its partial decomposition, and the hydrocarbons thus generated in the
retort or retorts descend and mix with the carbonic oxide gas near the grate or
openings, where the atmospheric air enters, to combine with the carbonaceous
constituent of the fuel. The rich hydrocarbons and tar vapours are here decom-
posed, and rendered capable of being conveyed through long tubes or channels,

page_text: and of being heated previons to combustion taking place, without leaving deposits
of tar or solid carbon on the way. The gases generated in the upright retorts may
however be taken off at or near to their upper extremity, and may be dealt with
separately as heating or even lighting gases.
If the fuel charged is "slack" or coal dust, then the retort arrangement above
described has the additional advantage of binding the mass together into imperfect
coke before reaching the grate, whereby it is rendered pervious to the atmospheric
air, and fit for active combustion. If the fuel binds very strongly, I dispense with
a regular grate, but substitute a solid inclined plane with one large slit or opening
at the top of the incline, for the admission of air and also for the occasional
introduction of a bar of iron, in order to break up the mass of solid coke. A large
opening at the foot of the inclined plane serves chiefly for the removal of clinkers,
but also for an additional admission of air in order to complete the combustion of
carbonaceous matter. A pool of water is formed under the inclined plane to
quench the ashes, and the steam thus formed, in passing with the air through the
mass of incandescent coke, combines with the same, forming carbonic oxide and
hydrogen gas.
This apparatus is particularly applicable for the production of combustible gases
from anthracite, coke dust, or decrepitating fuel, which can only be burnt with
great difficulty upon an ordinary fire-grate, because it does not present cavities or
interstices for the passage of the air. I mix this description of fuel with a certain
per-centage of binding coal, or with coal tar, oil, or with resenous matter, which, on
being heated in the retort, is decomposed, leaving a residue of carbon, which, in its
turn, binds the particles of dry carbonaceous fuel together into coherent masses
suitable for combustion upon a grate.
The combustible gases so formed may be burnt in any description of furnace or
fire-place, at any distance from the place of production. I prefer in most cases to
use for this purpose regenerative furnaces as described in certain Letters Patent
granted to myself in conjunction with Mr. Frederick Siemens on the 22nd January
1861, No. 167, for "Improvements in Furnaces." In cases however where an
intermittent heat is required, as for instance in burning pottery wares, I modify
the arrangement described in the Specification to the said Letters Patent by placing
only one single chamber filled with loosely piled bricks below or near the furnace
to be heated, and by directing the currents by means of valves or dampers in such
manner that at one time the gas burns within the chamber, heating the loose
brickwork, while the furnace or kiln above is allowed to cool, or is being charged,
whereas at other times air is caused to pass into the said chamber and, after being
heated therein, is caused to pass into the furnace or kiln in order to dry and heat
the materials contained therein; and again, at other times the beated air in rising
from the chamber is mixed with gas, which may have been heated or not, in order
to produce an intense heat in the furnace.
Another part of my Invention has reference to the cleaning of combustible gases
from dust, previous to their being burnt in furnaces. For this purpose, I conduct
them through narrowed and contracted channels passing into a large chamber or
reservoir, whence the gases escape through other openings in or near the roof of the
reservoir, in close proximity to the orifices of the aforesaid channels. The solid
particles of dust mixed with the gases are carried into the chamber with them at a
considerable velocity, and continue their course and fall to the bottom of the
chamber by virtue of their inertia and their gravity; whereas the gases turn sharply.
in order to reach the exits in or near the roof of the chamber whence they are
conducted to their destination in the usual manner. The chamber is opened from
time to time for the removal of the accumulated dust. In order to accelerate the
gas in the channels, I sometimes employ steam jets. This cleaning or purifying
apparatus is applicable with the greatest advantage for freeing the gas of blast
furnaces of the dust which generally accompanies it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles William Siemens in the Great Seal Patent Office on the
2nd June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME I CHARLES
WILLIAM SIEMENS of No. 8 Great George Street Westminster in the County of
Middlesex send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the Third day of December in the year of our Lord One
thousand eight hundred and sixty-four in the twenty-eighth year of Her reign
did for Herself Her heirs and successors give and grant unto me the said Charles
William Siemens Her special licence that I the said Charles William Siemens my
executors administrators and assigns or such others as I the said Charles William
Siemens my 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 APPARATUS FOR THE PRODUCTION
PURIFICATION AND COMBUSTION OF GASES FOR HEATING PURPOSES" upon the
condition (amongst others) that I the said Charles William Siemens my executors
or administrators by an instrument in writing under my or their or one of
their hands and seals 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 do hereby
declare the nature of the said Invention and in what manner the saine is to be
performed to be particularly described and ascertained in and by the following
statement thereof, reference being had to the accompanying Drawings and to
the figures and letters marked thereon that is to say;
These improvements relate to the construction of apparatus for converting
carbonaceous matter into combustible gases, for purifying such gases, and for their
application to the beating or fusing of metals and other substances. In order to
convert carbonaceous matter, such as coal, peat, or wood, into a combustible gas,
I adopt such an arrangement of apparatus that the fuel descends gradually through
one or more vertical or inclined retorts formed of cast iron, fire-brick, or other
suitable material, and is made to pass from the lower end of such retort or retorts
upon the fire-grate, or an inclined plate. with openings for the admissions of
atmospheric air. At this point combustion ensues, but the mass of fuel acted upon
being large, each particle of oxygen which enters will take up two particles or
equivalents of carbon, and produce carbonic oxide, which is a combustible gas. The
carbonic oxide gas thus formed, together with its necessary admixture of nitrogen,
is conducted upwards and over or around the external surfaces of the retort or
retorts through which the solid fuel descends, in order to impart its free heat to
the same before passing away to the furnace where it is to be consumed.
The heat thus communicated to the descending column or columns of fuel serves
to effect its partial decomposition, and the hydrocarbons thus generated in the
retort or retorts descend and mix with the carbonic oxide gas near the grate or
openings where the atmospheric air enters to combine with the carbonaceous
constituent of the fuel. The rich hydrocarbons and tar vapours are here decomposed
and rendered capable of being conveyed through long tubes or channels, and of

page_text: being heated previous to combustion taking place, without leaving deposita of solid
tar or carbon on their way. The gases generated in the upright retorts may
bowever be taken off at, or near to their upper extremity, and may be dealt with
separately as heating or even lighting gases.
If the fuel charged is "slack" or coal dust, then the rotort arrangement above
described has the additional advantage of binding the mass together into imperfect
coke before reaching the grate, whereby it is rendered pervious to the atmospheric
air, and fit for active combustion. If the fuel binds very strongly, I dispense with
a regular grate but substitute a solid inclined plane with one large slit or opening
at the top of the incline for the admission of air and also for the occasional
introduction of a bar of iron, in order to break up the mass of solid coke. A large
opening at the foot of the inclined plane serves chiefly for the removal of clinkers,
but also for an additional admission of air in order to complete the combustion of
carbonaceous matter. A pool of water is formed under the inclined plane to
quench the ashes, and the steam thus formed, in passing through the mass of
incandescent coke, combines with the same, forming carbonic oxide and hydrogen
gas.
This apparatus is particularly applicable to the production of combustible gases
from anthracite, coke dust, or decripitating fuel, which can only be burnt with
great difficulty upon an ordinary fire-grate, because it does not present cavities or
interstices for the passage of the air. I mix this description of fuel with a certain
per-centage of binding coal or with coal tar, oil, or with resinous matter, which, on
being heated in the retort, is decomposed leaving a residue of carbon which, in its
turn, binds the particles of dry carbonaceous fuel together into coherent masses
suitable for combustion upon a grate.
The combustible gases so formed may be burnt in any description of furnace or
fire-place at any distance from the place of production. I prefer in most cases to
use for this purpose regenerative furnaces as described in the Specification to
certain Letters Patent granted to myself in conjunction with Frederick Siemens on
the 22nd January 1861 No. 167 for "Improvements in Furnaces." Where an
intermittent heat is required, as for instance in burning pottery wares, I modify
the arrangement described in the Specification to the said Letters Patent by
placing only one single chamber filled with loosely piled bricks below or near the
furnace to be heated, and by directing the currents by means of valves or dampers
in such manner that at one time the gas burns within the chamber, heating the
loose brick work, whilst the furnace or kiln above is allowed to cool, or is being
charged, whereas at other times air is caused to pass into the said chamber and
after being heated therein is caused to pass into the furnace or kiln, in order to dry
and heat the materials contained therein; and again, at other times the heated air,
in rising from the chamber, is mixed with gas, which may have been heated or not,
in order to produce an intense heat in the furnace.
Another part of my Invention has reference to the cleaning of combustible gases
from dust previous to their being burnt in furnaces. For this purpose I conduct
them through narrow and contracted channels passing into a large chamber or
reservoir, whence the gases escape through other openings in or near the roof of the
reservoir, in close proximity to the orifices of the aforesaid channels. The solid
particles of dust mixed with the gases are carried into the chamber with them at a
considerable velocity, and continue their course and fall to the bottom of the
chamber by virtue of their inertia and their gravity, whereas the gases turn sharply
in order to reach the exits in or near the roof of the chamber, whence they are
conducted to their destination in the usual manner.
The chamber is opened from time to time for the removal of the accumulated
dust. In order to accelerate the gas in the channels, I sometimes employ steam
jeta. This cleaning or purifying apparatus is applicable with the greatest
advantage for freeing the gas of blast furnaces of the dust which generally
accompanies it.
On the accompanying Drawings are shewn the arrangements of apparatus which

page_text: I employ by preference for carrying the several parts of my Invention into
practice,
Figures 1, 2, and 3, on Sheet I. shew the arrangement of apparatus for converting
carbonaceous matter into combustible gases which I prefer to employ with fuel that
binds very strongly. Figure 1 shews vertical sections of three such gas producers
arranged side by side, the sections being taken respectively on the lines E F, GH
and IK Figure 3. Figure 2 shews respectively a plan of one of the producers,
sectional plan on the line N O, Figure 3, and a sectional plan on line L M
Figure 3 Figure 3 shews a vertical section on lines A B and C D Figure 1.
The same letters of reference indicate the same parts in each of the Figures.
The fuel is introduced through the openings a a into the vertical retorts b b, in
which it descenda slowly, the retorta being widened out towards the bottom,
shewn, to facilitate the descent of the fuel. The retorts are open at their lower
extremity, being supported by fire-brick arches g, and the fuel passes from them
in a thick layer, as indicated, on to the inclined plate c, at the upper and lower
end of which ure openings d. and e for the admission of air, and also for introducing
bars from time to time to break up the mass. An imperfect combustion results
from the passage of the air through the thick layer of incandescent fuel, and the
hot combustible gases thereby produced pass up into the space n on their way
towards the outlet pipe f, being there made to pass against a portion h of the
outer surface of the retorts b, so as to impart their free heat to the same, and
consequently also to the mass of fresh fuel descending through the retorta. The
fresh fuel is by this means partially decomposed, and the resulting rich hydrocarbon
gases, are made to descend through the retorts (the openings a a being closed, either
simply by the fuel in a pulverulent form, or by incans of covers or by hoppers
with slides of well known construction) and mix with the carbonic oxide and other
gases produced below, the combined gases being conducted through the outlet pipe f.
and main i to the furnaces or wherever required. As the conversion of the fuel into
combustible gases progresses, the inconvertible constituents, or ashes and clinkers,
accumulate at the bottom of the inclined plate, whence they are removed from time
to time through the opening e. The ashes are quenched in a pool of water at j
admitted through a pipe k, and the resulting steam, in passing through the mass of
incandescent fuel, also becomes decomposed, forming combustible gases which mix
with the rest. Or in place of or in addition to the water, steam may be introduced
through the pipe k.
The top of the producers are level with the ground line, in order to obtain an
ascending column of gas of sufficient height in the pipes to insure the requisite
draught in cases where the furnace or place of combustion is also situated low.
Access is gained to the ash-pits from the stroke-hole b. m m are apertures, closed
by covers, for clearing out the gas passages when required.
Figures 4, 5 and 6 shew the arrangement of this apparatus which I employ
when fuel of a less binding nature is to be converted.
Figures 4 and 5 shew sectional elevations of a series of threo producers taken
on the various lines PQ, R S, and T U, and Figure 6 shows a corresponding plan
partly in section on line V W, Figure 5.1
The general arrangement of the producers is the same as that of the apparatus
before described, and the several corresponding parts are therefore designated by
the same letters of reference. The principal difference consists in the arrangement
of the gas passages and retorts, which are here constructed in such a manner that
the hot gases on their way to the pipes fare made to pass completely round and
against the outer surface of the retorta b, which are also made considerably thinner
than in the preceding arrangement, in order that the free heat of the gases may be
more completely imparted to the fuel passing down in the retort. Also, in place
of the inclined plate before described, a step-grate c is here employed so as to
admit air more freely in amongst the mass of fuel. The other parts being the same
as in the other arrangement, they need not be further described.
Figures 7 8 and 9 on Sheet II. of the accompanying Drawings show an

page_text: arrangement of the before-described furnace, kiln, or oven, worked by one single
regenerator. Figure 7 shews a vertical section, Figure 8 shews a sectional plan
on line E F. Figure 7, and Figure 9 shews a sectional plan on line G H, Figure 7.
The arrangement here shewn is specially applicable as a kiln or oven for burning
pottery and similar goods. The kiln or oven is for this purpose provided with
several openings b, b, b all round for charging and discharging the goods, which
openings are bricked up as shewn when the oven is in operation.
Immediately beneath the kiln or oven is the regenerator c or chamber filled
with loosely piled brick work, a passage or space d being formed between the roof
of the regenerator and the floor of the oven. The regenerator communicates at
top with this space d through the opening e, and with the kiln or oven a through
the opening f, which latter may be closed by means of the slab g. The space d,
and consequently the top of the regenerator can also communicate through the
passage h with the passage h, through which atmospheric air enters, and this latter
passage can also communicate with the bottom of the regenerator through the
passage , the admission of the air either to the top or bottom of the regenerator
being regulated by means of the reversible valve or damper i. By means of this
damper also it will be seen that when the passage h is made to communicate with
the top of the regenerator, as in the position shown, the passage A is made to
communicate with the chimney; through the passage k. The regenerat or furthermore
communicates at top with the passage for combustible gas 1 through the central tube
of fire-clay, which is provided at top with a description of burner m having
openings m' through which the gas can issue either into the regenerator or through
the openings e, f into the oven or kiln a; the latter also communicates with the
chimnies j, j through the openings n, n.
From this arrangement it will be seen that if it is required in the first instance
to heat the regenerator e whilst the kiln or oven a is being charged with fresh
goods, the opening fis closed by the slab g actuated through an opening at o, and
combustible gas is admitted to the top of the generator through the passages 1, 11;
at the same time the valve i is placed in the position shown, so that air passes
from the passage A through the passage h, space d and opening into the
regenerator, where, meeting with the gas issuing from the burner m, it enters into
combustion with the same. At the same time it will be seen that the regenerator
is made to communicate at bottom with the chimney j through the passages h
and k, so that the hot gaseous products of the combustion that is taking place at
the top of the regenerator are drawn down through the latter, and impart their
heat to the loosely piled brick work contained therein. When the regenerator has
by this means been heated to a sufficiently high degree, or when the charging of
the goods in the kiln a is completed, and it is required to fire them, then the slab g
is withdrawn from the opening f, the position of the valve i is changed, and the
passage k is closed by means of the slab p, when it will be seen that the air will
pass through the passage into the bottom of the regenerator, will pass up
through the same, thereby becoming highly heated, and will then enter into
combustion with the gas issuing from the jet m, the resulting intensely heated flame
and products of combustion passing through the opening finto the kiln a, and
thence into the chimneys j. through the openings n, n, after firing the goods
contained in the kiln. If, on the other hand, it is only required to supply a
moderate heat to the kiln for the purpose of drying the goods, the supply of com-
bustible gas is cut off by means of a valve or damper in the passage, and the
atmospheric air alone, heated by its passage upwards through the regenerator, is
allowed to pass into the kiln; or even the supply of air may be cut off by means
of a damper in the passage A, and the kiln warmed simply by the radiated heat
from the regenerator.
Although I have described the arrangement as applied to an oven for firing
pottery ware, yet it is evidently equally applicable for other purposes where a
great heat is periodically required. By placing crucibles on the bed of the furnace,
it may also be applied to the smelting of steel

page_text: Figures 10 and 11 on Sheet II. shew an arrangement of my improved apparatus
for purifying combustible gas from dust. Figure 10 shows a vertical section and
Figure 11 shows a sectional plan. The receptacle a is divided by means of a
diaphragm b into a lower chamber c and upper chamber d. A communication
between the two chambers is established by means of the trumpet-mouthed pipes
e, e, e, arranged in a circle and suspended from the diaphragm b. In the lower
trumpet-mouthed openings of each of these pipes is fixed a double conoid f, f,
whereby the orifice of each pipe just above the trumpet-mouth is contracted to a
narrow annular form as shown. A number of stnall jets g, g, g are arranged, one
opposite each of the tubes e, through which jets steam is made to issue in a
downward direction, so that, the gas being made to flow into the chamber d through
the pipe h, the velocity with which it flows through the pipes e into the chamber of
is greatly increased by the action of the steam jets. This velocity is still further
increased as the gas passes through the contracted annular orifices of the pipes,
but on passing thence into the trumpet-mouthed openings the velocity of the gus
will be suddenly checked by its expansion, whilst the dust contained therein, not
being affected by any such expansion, will, by virtue of its greater momentum,
continue to pass with considerable velocity in a downward direction to the bottom
of the chamber c. At the same time the gas, as it passes into the chamber, is
immediately drawn upwards to the mouth of the outlet pipe i, as indicated by the
arrows, through which pipe it passes down into the passage ; whence it flows to
the furnaces or wherever required. If necessary the sucking action of the pipe
may be increased by drawing the gas through the passage by means of a fan
exhauster, or other similar known coutrivance. The dust, as it collects at the
bottom of the chamber c, is removed from time to time through the man-holes k, k,
and a man-hole is also provided to the pipe i to remove any dust that may pass
down with the gas and collect at the entrance of the passage j, which is there made
somewhat deeper for that purpose as shown.
Similar man-holes m, m, m are also provided to the upper chamber d for the
purpose of clearing the same from dust from time to time. The steam jets g, g,.
besides imparting greatly increased velocity to the gas and dust passing through
the tubes, have the further effect of moistening and thus rendering heavier the
purticles of dust contained therein, thereby still further facilitating their separation
from the gas, and preventing them from flying about in the chamber c. Although,
for the above reasons, I prefer to employ the stean jets, yet if the gas is made of
itself to pass with sufficient velocity through the pipes e, these jets may be
dispensed with.
It will be evident that various other arrangements of this apparatus may be
adopted. Thus it may consist simply of a long chamber into one end of which the
gas is caused to flow in a more or less horizontal direction, the chamber having
slits or openings at or near the top through which the gas escapes into a closed
surrounding chamber whence it is drawn off to wherever required.
Having now described the nature of the several parts of my Invention and the
manner in which they are to be performed, I wish it to be understood that I do
not limit myself to the precise details of the several arrangements of apparatus
herein-before described with reference to the accompanying Drawings, as these may
be variously modified as herein-before stated without departing from the nature of
my Invention. Nor do I claim generally the arrangement of apparatus for con-
verting carbonaceous matter into combustible gases into which such carbonaceous
matter is introduced through a hopper and is caused to descond upon an inclined
plane in a thick layer before reaching a grate, as such an arrangement was
described in the Specification to the before-mentioned Letters Patent granted to
me and Frederick Siemens But what I claim is
First. Constructing apparatus for converting carbonaceous matter into com-
bustible gases in which such carbonaceous matter is first caused to descend
gradually through one or more vertical or inclined retorts, from the lower end of
which it passes in a thick layer upon a fire-grate, the heated combustible gases

page_text: resulting from the imperfect combustion of the fuel upon the latter being made to
pass around or against the outer surface of the said retort or retorts.
Second. Constructing gas producers (which are chiefly applicable for the con-
version of binding coal into combustible gas) in such a manner that the fuel
descends through an inverted funnel, acting more or less as a retort, upon a solid
moderately inclined plane supporting the colmmn of fuel, such inclined plane
having one or more openings at the top for the adinission of atmospheric air as
well as for the introduction of bars to break up the masses of coke, whilst one or
more other openings are provided at bottom for the removal of clinkers and ashes,
and for the introduction of a further quantity of air or steam, or both, in order to
complete the conversion of the carbonaceous matter, substantially as herein-before
described with reference to Figures 1, 2 and 3 on Sheet I. of the accompanying
Drawings.
Third. So arranging furnaces, ovens, or kilns in combination with one single
regenerator, or chamber filled with loosely piled fire-bricks, and regulating the
admission of atmospheric air and combustible gases thereto, that at one time the
combustion of air and gas can take place within the regenerator for the purpose of
heating the same, whilst at another time either the air or the combustible gas alone
passes through the regenerator that has been thus heated, and enters into com-
bustion with the gas or air on its entrance into the furnace, oven, or kiln; or
atmospheric air only is made to pass through the heated regenerator in order to
convey the heat thereof into the furnace, oven, or kiln, substantially as described
with reference to Figures 7 to 9 on Sheet II. of the accompanyings Drawings.
Fourth. Constructing apparatus for purifying combustible gases from dust in
which the superior momentum of the particles of dust is made available for
separating it from the gas, by causing the gas containing the same to pass with
considerable velocity through narrow and contracted passages into a chamber or
reservoir, in which the motion of the gas is immediately checked and its direction
changed by being drawn into the openings of other passages situated at or near
the top of the chamber, whilst the dust contained therein proceeds onwards in the
chamber in its original direction, or nearly so, which operation may with advantage
be furthered by the application of steam jets, substantially as herein-before
described with reference to Figures 10 and 11 on Sheet IL of the accompanying
Drawings.
In witness whereof I the said Charles Williams Siemens have hereunto set
my hand and seal this Thirty-first day of May in the year of our Lord
One thousand sight hundred