Improvements in the Construction of Furnaces for Producing Perfect Combustion.
Year: 1891

page_text: Date of Application, 8th July, 1891
Complete Specification Left, 2nd Apr., 1892-Accepted, 7th May,
1892
PROVISIONAL SPECIFIATION.
Improvements in the Construction of Furnaces for Producing
Perfect Combustion.
I, JOSEPH HINSTIN of 16 Rue Drouot, Paris, in the Republic of France, Civil
Engineer do hereby declare the nature of this invention, to be as follows:-
The object of this invention is to provide a new arrangement of furnace in which
a complete combustion takes place, and which is characterised by the combination
of the three following elements:-
1st. A front furnace, 2nd. a furnace properly so called, and, 3rd. a back furnace,
the shape and dimensions of which latter may vary according to the kind of fuel to
be used in the furnace, and which back furnace may be formed of chambers into
which the air necessary for combustion is caused to penetrate by means of nozzles,
gratings or air passages. which are of such sizes and dimensions as are best suited
for the fuel employed, this latter being itself held up or supported according as the
case may require by means of bars of variable shapes according to the state of the
fuel employed.
'
1. The front furnace is the part in the new arrangement of furnace in which the
distillation of the gases from the fuel is effected, and the mixture of the former
with air takes place in proportion as the fuel becomes more and more heated; such
mixture of gases and air is carried off from this front chamber and is thrown down
into the draught chamber which ends in a combustion nozzle over incandescent
coke. It is this part of the new arrangement where what is usually termed smoke
consuming is performed. It is formed of a chamber enclosed on the one hand by
grate bars of variable shape and position, according to the state of the fuel,
arranged vertically or horizontally and fitted or not with air- and gas-conductors,
regulated, if need be, by registers, intended to cause the air to penetrate the mass
of fuel, the whole serving-to hold up the latter if requisite, and to facilitate the
admixture and exit of the air and gas; on the other band, by a counter grate also
variable in shape, and which serves to bring the mixture of air and gas to the
furnace properly so called, this front grate may be specially fitted with bars having
the shape of gutters so as to allow of liquid fuels being burnt by mixing them with
the solid fuel placed in the front furnace.
2. The furnace proper is that part of this new arrangement of furnace in which
the distillation of the gas is continued and completed, where the combustion of the
mixture of gas and air coming from the back grate is performed, and where the
transformation of the combustible gases and carbonic acid commences; it is formed
of a chamber bordered on the one hand by the front furnace, and, on the other
hand, in front by a fire grate intended simply for lighting and cleaning purposes
and by fixed or movable grate bars, more or less inclined or arranged horizontally
and provided or not with air passages, which may have applied to them suitable
registers for allowing the air to penetrate into the body of the fuel which the bars
may hold up if required; and, finally, on the other hand, by the back furnace.
The furnace has further an ashpan and the door of the ashpan, in which a register
is fixed, which regulates the admission of air under the furnace grate.
3. The back furnace is the part of this new arrangement of furnace in which the
combustion is terminated and completed by the transformation of the combustible
gases into carbonic acid; it is formed of a chamber enclosed on the one hand by
the furnace properly so called; on the other hand, by the fire bridge and the arch
for throwing down the flames which covers or surrounds it, and has, in its lower
part, bars serving to hold up the iguited fuel and which necessarily, presents, to the
layer of fuel, a triangular section, the base of which is connected with the actual

page_text: furnace, and the summit with the opposite end of the bars on the side of the bridge;
these bars form a grate which may have an up and down motion for shaking up the
fuel and for increasing the passage of the air supplied by a register, oscillating or
otherwise, and which distributes the air as desired under the grate of the furnace,
or under that of the back furnace; this back furnace is further made complete by
three air inlets placed at the angles of the triangle, that is, one at the entrance of
the back furnace, above where the fuel is thickest, a second at the lower extremity
of the movable grate below where the fuel is thickest, and the third at the upper
end of the movable grate at the summit of the triangle at a point where there is no
thickness of fuel, these two last air inlets being regulated by means of a lever
which allows of the movable grate being more or less inclined.
The various arrangements in which this invention may be carried out all have-
1st: A front furnace acting in the same way as the front part of the grate of
an ordinary furnace, erected vertically and overhanging the lower part which
supports the incandescent coke.
2nd. The furnace proper;
3rd. A back furnace.
The front furnace, which is surmounted where necessary by a charging hopper
for the fuel, is of dimensions suitable to the consumption of fuel and the time of
distillation, with as large a capacity as possible, for a part of the carbonic oxide
formed in the furnace rises somewhat into the front furnace and may be advan-
tageously treated like the gases, from a point of view of combustion. The form to
be given to this front grate will depend essentially on the nature of the fuel to be
consumed therein. If the fuel be adhesive, a form of front furnace may be
preferably employed in which the descent of the fuel may be facilitated by
widening out the front furnace at the bottom. If, on the other hand, the fuel be
slippery, fine and dry, it would be preferable to sustain it by having the narrower
section below and by using flat grates.
The air necessary for producing the mixture with the gases of the fuel is
introduced into this front furnace by a grate, which may be also of various forms
and sections according to circumstances and requirements; these grate bars may
be arranged vertically or horizontally, as required, and may be of different useful
forms; in the arrangement, especially, of a grate held up by supports, heavy oils
may be caused to run into the hollow parts of this latter, which oils could be fed by
& pipe and distributed by tubes having taps, these oils burning simultaneously with
the solid combustible placed in the chamber of the front furnace.
The admission of air into the front chamber is regulated by means of a regulating
register situated in the inspection door, for this purpose any combination of known
devices may be employed.
Opposite to the grate for the admission of air into the front furnace, is the
countergrate sustained by means of supports and serving to keep the fuel in the
front furnace at a suitable thickness, whilst allowing the air and gas after having
passed through the layer of fuel to re-unite and become finally mixed behind this
countergrate in a chamber where the draught acts and brings the mixture over the
incandescent coke. This countergrate is made like an ordinary grate with an
arrangement for cooling the bars which are nearest to the heat of the fire by means
of a circulation of water or air. In certain cases, this countergrate may be
advantageously replaced by a similar arrangement in brick or fireclay or simply by
fireclay walls which are more or less undulated, thereby increasing the surfaces of
small resistance if not to form actual chambers.
Between the grate and the counter grate, if it be necessary, air- or gas-
conductors, are placed, held up by supports and intended to allow a sufficient
quantity of air which is indispensable for mixing with the gases and for their total
combustion to penetrate the mass of fuel, and which also serve to facilitate the
passing away of the mixture. The aëration of the fuel may, in many cases, take
place of itself between the two grates, the latter being given a suitable form, and
the layer of fuel being of such a thickness as to allow the air to easily penetrate it,

page_text: be
but if, for any reason, such for instance as for facilitating the descent of the fuel,
it is necessary to increase the width of the layer of fuel at the bottom of the front
furnace to such a point that a larger quantity of air is necessary, recourse may
had to this method of aëration. This air conductor may be made either in the form
of a flat bar, or in that of two bars simply placed side by side or arranged in a
triangular form, or even may be made of partitions in the form of grates allowing
of such quantities of air as may be necessary being brought in every direction.into
the mass, and at the same time of the gas produced being carried off.
The number and nature of the bars forming these gas conductors may naturally
be varied according to circumstances, and the admission of air into these conductors
may be regulated as desired by means of plugs forming registers, or by any other.
suitable means.
According to the fuel which is to be consumed, these air conductors must have.
different shapes. If, for instance, the combustible is to descend easily, they must
have very acute angles, but if, on the contrary, their object is to bring air into a
very compact but sliding mass, such, for instance, as coke dust, they must assume
the form of obtuse bars, thus supporting the fuel. In this particular case, grate
bars might even be preferably employed having projections cast in one piece with
the bars.
The furnace properly so called is like all furnaces formed of the following
parts:
1: The door, which may be of a shape resembling movable plugs, and be per-
forated, and have a register allowing air to be admitted in greater or less quantity..
This door which is placed in the front of the furnace is variously arranged. It
may be usually smaller than the doors of ordinary furnaces, because it is not
generally used for charging. It is used for lighting the fire and for assisting the
cleaning. The door of the furnace may have retaining hooks for placing paddles
or pokers on under the front furnace and for holding up the fuel in the case it
desired to empty the furnace alone.
2. The grate, which is formed by the bars as usually employed, of various more
or less inclined shapes placed according to requirements and the nature of the fuel
and held up by supports.
The part called, in the preceding, the air and gas conductor in the front furnace
may also be made to serve for this grate, or there may be employed bars having
additions of points or projections capable of supporting the fuel whilst introducing
into the mass the air which is necessary for the mixture with the gas in proportion
as it is produced..
If a fine but not adhesive fuel is. to be dealt with, such, for instance, as coke
dust, the bars may be arranged in such a way that the layer of coke is as thin as
possible to allow of the passage of the air. In order, however, to have at a given
point a sufficient quantity to produce and maintain the incandescence, the grate may
be divided into one or more parts by means of movable grates, the effect of which
is, not only to multiply the incandescent masses, but also to cause currents of air to
pass from place to place behind the movable grate.
3rd. The regulating register for the admission of air under the furnace properly -
80 called is fixed in the door itself of the ashpan, and it is made in any suitable
known manner.
The back furnace, which adjoins the actual furnace, is essentially composed of a
combustion inlet or nozzle for the gases of the front furnace, of a movable grate,
of a bridge, of a part for throwing down the flame with an arch for radiating the
heat, and of a regulating register for the admission of air.
The combustion nozzle, for the gases of the front furnace, is placed at such a
point that the gases shall be able to pass.exactly between this point and the bridge
on the one hand,, and the surface of the incandescent fuel on the other, without
spoiling the draught. This point forms the entrance of the back furnace.
This entrance is generally formed like a bridge with an air collector to preserve
it from too rapid a deterioration. The entrance of the back furnace has the

page_text: essential effect, first, of forcing the mixture of air and gas coming from the front
furnace to pass down as close as possible to the incandescent fuel on the grate of the
furnace proper; second, of introducing air in excess on to the incandescent fuel at
the point where it is thickest and highest, at the entrance of the back furnace, and,
consequently, at the point where the most carbonic oxide is produced; and, third,
of producing the intimate mixture of the same by throwing them down, then to
produce the combustion of the mixture by forcing it to pass in proximity to the
incandescent coke.
According as to whether the bridge of the back furnace is more or less elevated
with the entrance inlet always lowered to the maximum extent, the flame may be
more or less deflected, which may, however, always be limited by the construc-
tion of the arch for throwing down the flame, and by the necessities of the
installations:
The movable grate of the back furnace is composed of bars, the forms and sections
of which are suited to the nature of the fuel; but connected among themselves in such
a way that all the grate, as a whole, or part thereof, may turn on an axis, being
caused to move by means of levers. The grate is arranged in such a way that one
of its extremities ends at the natural line of slope of the incandescent fuel, at its
exit from the front furnace.
This grate may terminate, at its upper end, in a hook or catch which will retain
the combustibles and will render the working of the movable grate more exact, as
regards the introduction of air into the back of the furnace for the purpose of
effecting the total combustion of the carbonic oxide. But the movable grate of the
back furnace may, at the same time, serve to cause the cinders contained in the
incandescent fuel to fall out.
For that purpose, it is sufficient to give a back and forward motion to the grate
by means of levers which act directly on the axis of the grate or otherwise. In
this way, either the whole or a part of the grate of the furnace proper may be made
to move at the same time, by causing it to como in contact with the extremity of
the movable grate.
The bridge does not exhibit anything particulur, unless, in this arrangement
of back furnace, it becomes the auxiliary of the movable grate, in order to
allow a greater or smaller current of air to penetrate perpendicularly to the
direction of the combustible gases, by means of a channel or passage, which
distributes the air under the grate of the back furnace. It may be constructed in
any known way, and with or without air circulation, as may be required, and to aid
in the deflection of the flame.
The dome of the back furnace for deflecting the gases and for effecting the
radiation of the heat is arranged so as best to fulfil these two purposes in view of
its applications and needs, and, as far as possible, in such a way as to cause the
heat to radiate at the point where the mixture of air and gas is the greatest.
The object of the deflection of the flame is to complete the mixture of the air
and the combustible gases, and that of the vault to complete the combustion of the
mixture.
The admission of air into the back furnace is simultaneously regulated with the
admission of air under the grate of the furnace proper, by means of a register
placed in the door of the ashbox. The air, if desired, may be divided between the
grates of the two furnaces by means of the movable partition placed between the
ashbox of the furnace proper and that of the back furnace.
The air collector, placed at the entrance of the back furnace, also sends warm air
by a pipe placed in the bridge under the grate of the back furnace. A portion of
the air of this collector may be sent to the gas combustion nozzle of the front furnace,
or to any other suitable place; in pottery furnaces, especially, such inlets of air may
be also regulated by suitably placed registers.
The different industrial furnaces, as above, have been so described under the
supposition that they worked always with an oxidising flame producing carbonic
acid in order to yield-the most complete combustion, but, in certain cases,
may. be

page_text: necessary to cause the furnace to work otherwise, for instance, in the cise of a
steam boiler, if the temperature be too high at the point of contact with the fire, or
in the case of pottery furnaces. For this purpose, a portion of the warm air, which
is usually caused to come to the back furnace, is diverted, and is directed by means
of a pipe and a valve, suitably placed at the extremity of the first 'contact point of
the fire, to a point capable of still heating a brick to redness, and, at this point, a
fire brick arch is formed, which forces the current of the products of combustion to
pass downwards. A groove may be made at this point, if necessary, in the bottom
of the flue, in order to leave a sufficient width for the passage of the products of
combustion.
In pottery furnaces, when the first half of the furnace is acid, and brought to an
incandescent redness, this first may act in a similar manner to what the arch above
mentioned would do, and, by bringing the necessary air to this point whilst the
furnace is being worked with carbonic oxide, a second centre of combustion is
obtained which serves to facilitate the second part of a baking in the furnace.
Among the different parts which have just been described, some which would'
exist in some arrangements need not exist in others where they would be useless
or superfluous. In exchange for that there are supplied some details such as:-
A regulating valve fixed on the door of the ashpan or otherwise, and intended to
allow the air to penetrate under the furnace proper ;
An opening for the escape of the smoke ;
A fire clay fire.plate;
A damper fitted with a handle;
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
COMPLETE SPECIFICATION,
Improvements in the Construction of Furnaces for Producing
Perfeot Combustion.
I, JOSEPH HINSTIN of 16 Rue Drouot, Paris, in the Republic of France Civil
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
The object of this invention is to provide a new arrangement of furnace in which
a complete combustion takes place and which is characterised by the combination of
the three following elements; first, a front furnace; second, a furnace properly so
called; and, third, a back furnace, the shape and dimensions of all of which may
vary according to the kind of fuel to be used in the furnace and which back furnace
may be formed of chambers into which the air necessary for combustion is caused
to penetrate by means of nozzles, gratings or air passages which are of such sizes
and dimensions as are best suited for the fuel employed, this latter being itself held
up or supported according as the case may require by means of bars of variable
shapes according to the state of the fuel employed.
.
1. The front furnace is the part, in this new arrangement of furnace, in which
the distillation of the gases from the fuel is effected, and the mixture of the former
with air takes place in proportiou as they are produced by the progressive heating
of the fuel, such mixture of gases and air being carried off from this front chamber
and thrown down into the draught chamber which ends in a combustion nozzle over
incandescent, coke. It is formed of a chamber euclosed on the one hand by grate
bars of variable shape. and position according to the state of the fuel arranged

page_text: vertically or horizontally and fitted or not with air- and gas-conductors, regulated,
if need be, by registers intended to cause the air to penetrate the mass of fuel, the
whole serving to hold up the latter if requisite and to facilitate the admixture and
exit of the air and gas on the other hand, by a counter grate also variable in
shape and which serves for discharging the mixture of air and gas into a chamber
where the action of the draught is freely exerted and from whence the mixture of
air and gas is conveyed above the furnace properly so called; this front grate may
be specially fitted, in some cases, with bars having the shape of gutters so as to
allow of liquid fuels being burnt by mixing them with the solid fuel placed in the
front furnace.
2. The furnace proper is that part of this new arrangement of furnace in which
the distillation of the gas is continued and completed, where the combustion of the
mixture of gas and air coming from the front grate performed, and where the
combustible is maintained in an incandescent mass; it is formed of a chamber
bordered on the one hand by the front furnace and on the other hand in front by a
fire grate intended mainly for lighting and cleaning purposes, and by fixed or
movable grate bars more or less inclined, and provided, or not, with air passages,
which may have applied to them suitable registers for allowing the air to penetrate
into the body of the fuel which the bars may hold up if required; and, finally, on
the other hand by the back furnace. The furnace also includes the ash
pan, and
the door of the ash pan, in which a register is fixed which regulates the admission
of air under the furnace grate.
3. The back furnace is the part of this new arrangement of furnace in which the
combustion is terminated and completed by the transformation of the combustible
gases into carbonic acid ;- it is formed of a chamber enclosed on the one hand by
the furnace properly so called; on the other hand, by the fire bridge and the arch,
for throwing down the flames, which adjoins it, and has in its lower part bars
serving to hold up the ignited fuel placed in such a way as to necessarily present
to the layer of fuel a triangular section, the baso of which is connected with the
actual furnace, and the summit with the opposite end of the bars on the side of the
bridge; these bars form a grate to which may be imparted an up and down motion
for shaking up the fuel, and for increasing the passage of the air through the same
without prejudice to the facility which it affords for cleaning the same; the fire
bridge being arranged in such a way as to allow a layer of air, supplied by special
pipes, to enter under the grate against the wall of the fire bridge. The entrance
of this air being regulated by means of registers in such a way that the back
furnace thus operates independently of the furnace properly so called: its ash pan
is separated from that of the furnace properly so called by an oscillating or other
register, which supplies air as desired under the grate of the furnace or that of the
back furnace this back furnace being further completed by an air inlet placed, if
requisite, at the entrance of the back furuace, above where the fuel is thickest and
at one of the angles of the triangle which forms the section of the fuel, this latter
air inlet being regulated by means of a lever which allows of the movable grate
being more or less inclined, and thus the admission of air to the other two angles
of the same triangle to be increased more or less.
In order to facilitate the comprehension of the description, reference is made to
the accompanying six sheets of drawings, which represent, by way of example,
various applications of this new arrangement of furnace.
In these drawings :
Figure 1 represents an elevation in section on line G H I K of Figure 2 of an
industrial furnace arranged according to this invention.
Figure 2 represents a half plan view, in section, of the same furnace taken on the
line A B C D E F of Figure 1; and
Figure 3, a half front elevation of the same furnace, the shutters forming the
register for the admission of air being removed at certain points.
Figure 4 represents an elevation in section on the line EF of Figure 5 of an
industrial furnace for liquid fuel arranged according to this invention.

page_text: Figure represents a half plan view in section of the same furnace on the
line A B C D of Figure 4, and
Figure 6, a half front elevation of the same graté.
Figure 7 represents a side elevation of a kitchen furnace arranged according to
this invention.
Figure 8 is a sectional elevation of the same furnace on the line C D of
Figure 9, and
Figure 9 shows the sectional plan view of the same on the line A B of
Figure 8.
.
Figure 10 shows a half elevation of a warming stove arranged according to this
invention,
Figure 11, an elevation of the same in section on the line E F G H of
Figure 12, and
Figure 12 shows a sectional plan view of the same on the line A B C D of
Figure 11.
Figures 13 and 14 show arrangements of combined furnaces for burning coke
dust and characterised by a special combination of the grates of the furnace and
the back furnace.
Figures 15, 16 and 17 show views in transverse sectional plan on the line X Y
of Figure 15, and in half front elevation, of a modification of an industrial furnace
constructed according to this invention.
Figure 18 is a detail of a constructive part of the same furnace.
Figures 19 and 20 show views in transverse section and front elevation of a
particular method of constructing the bars intended to hold up the fuel in the front
furnace.
In these various figures, the same reference letters represent the same parts.
These various arrangements all have:-
1. A front furnace a acting in the same way as the front part of the grate of an
ordinary furnace erected vertically and overhanging the lower part which supports
the incandescent cuke;
2. The furnace propor b ;
3. A back furnace c.
10
The front furnace a, which is surrounded where necessary by a charging hopper
for the fuel, is of dimensions suitable to the consumption of fuel and the time of
distillation, with as large a capacity as possible, for a part of the carbonic oxide
formed in the furnace rises somewhat into the front furnace and may be advan-
tageously treated, like the gases, from a point of view of combustion. The form
to be given to this front grate will depend essentially on the nature of the fuol to
be consumed therein. If the fuel is adhesive, a form of front furnace may be
preferably employed such as is shown in Figure 1, that is to say, the descent of
the fuel may be facilitated by widening out the front furnace at the bottom. If, on
the other hand, the fuel be slippery, fine and dry, it would be preferable to sustain
it by having the narrower section below and by using flut grates.
The air necessary for producing the mixture with the gases of the fuel is
introduced into this front furnace by a grate d which may also be of various forms
and sections according to circumstances and requirements; these grate bars may be
arranged vertically or horizontally as required and may be of different useful
forms; in the arrangement especially of a grate held up by supports o¹.o', shown
in Figures 4 and 5, heavy oils may be caused to run into the hollow parts of this
latter, which oils could be fed by the pipe and be distributed by the tubes y
having taps z, these oils burning simultaneously with the solid combustible placed
in the chamber of the front furnace.
The admission of air into the front chamber is regulated by means of a regulating
register situated in the inspection door h, for this purpose, any combination of
known devices may be employed.
Opposite to the grate for the admission of air into the front furnace is the
counter grate k sustained by means of supports 1, Figure 4, and serving to keep

page_text: the fuel in the front furnace at a suitable thickness, whilst allowing the air and gas,
after having passed through the layer of fuel, to reunite and become finally mixed
behind this counter grate in a-chamber where the draught acts and brings the mixture
over the incandescent coke. This counter grate is made like an ordinary grate
with an arrangement for cooling the bars which are nearest to the heat of the fire
by means of a circulation of water or air. In certain cases, this counter grate,
and in fact the grate proper itself, may be advantageously replaced by a similar
arrangement in brick or fireclay, or simply, as shown in Figure 11, by fire clay
walls which are more or less undulated, thereby increasing the surfaces of small
resistance if not forming actual chambers.
The arch of the furnace, the chamber of releasing the mixture of gases, and the
counter grate may, if required, be made of a single piece either of metal, having a
cooling circulation transversely or laterally by conductibility, or in fireclay in one
or more parts, and may, if desired, serve for returning the flame towards the front
of the furnace as shown in Figures 19 and 20.
Between the grate and the counter grate, if it be necessary, air- or gas-con-
ductors are placed (Figures 1 to 6) held up by supports u and intended to allow a
Bufficient quantity of air, which is indispensable for mixing with the gases and for
their total combustion, to penetrate the mass of fuel, and which also serve to
facilitate the passing away of the mixture. The aëration of the fuel may, in many
cases, as in Figures 8 to 11, take place of itself between the two grates, the latter
being given a suitable form, and the layer of fuel being of such a thickness as to
allow the air to easily penetrate it, but if, for any reason, such for instance as for
facilitating the descent of the fuel, it is necessary to increase the depth of the layer
of fuel at the bottom of the front furnace to such a point that a larger quantity of
air is necessary, recourse may be had to this method of aëration. This air con-
ductor may be made either in the form of a flat bar, or in that of two bars simply
placed side by side or arranged in a triangular form, or even may be made of
partitions in the form of grates allowing of such quantities of air as may be
necessary being brought in every direction into the mass, and, at the same time, of
the gas produced being carried off.
The number and nature of the bars forming these gas conductors may naturally
be varied according to circumstances, and the admission of air into these conductors
may be regulated as desired by means of plugs forming registers, or by any other
suitable means.
According to the fuel which is to be consumed, these air conductors must 'have
different shapes. If, for instance, the combustible is to descend easily, they must
have very acute angles, but if, on the contrary, their object is to bring air into a
very compact but sliding mass, such, for instance, as coke dust, they must assume
the form of obtuse bars, thus supporting the fuel. In this particular case, grate
bars might even be preferably employed having projections cast in one piece with
the bars, such as are shown in d" in Figure 13.
The furnace b properly so called is like all furnaces formed of the following
parts-
1. The door i, which may assume the form of movable plugs, or be perforated,
and have a register allowing air to be admitted in greater or less quantity. This
door, which is placed in the fronts of the furnace, Figures 1 to 6, is variously
arranged. It may be usually smaller than the doors of ordinary furnaces, because
it is not generally used for charging. It is used for lighting the fire and for
assisting the cleaning. The door of the furnace may have retaining hooks, for
placing paddles or pokers on, under the front furnace, and for holding up the fuel
in case it is desired to empty the furnace alone.
་
2. The grate, which is formed by the bars e as usually employed of various more
or less inclined shapes placed according to requirements and the nature of the fuel
and held up by supports v. The part called, in the preceding, the air and gas con-
ductor, in the front furnace may also be made to serve for this grate, or there may
be employed bara having additions of points' or projections, 'as shown by P,

page_text: Figure 13, capable of supporting the fuel whilst introducing into the mass as
much air as is necessary for its mixture with the gas in proportion as it is
produced.
If a fine but not adhesive fuel is to be dealt with, such, for instance, as coke
dust, the bars may be arranged in such a way that the layer of coke is as thin as
possible to allow of the passage of the air. In order, however, to have at a given
point a sufficient quantity to produce and maintain, the incandescence, the grate may
be divided into one or more parts by means of movable grates, the effect of which
is not only to multiply the incandescent masses, but also to cause currents of air to
pass from place to place behind the movable grates.
3. The regulating register r, for the admission of air under the furnace properly
BO called, is fixed in the door itself of the ash pan g and it is made in any suitable
known manner.
The furnace proper, such as just described, differs little, as may be seen, from an
ordinary furnace, its principal characteristic. consists in the peculiar position which
it occupies as regards the front and back furnaces. This position is, as regards the
front furnace, such that the furnace proper serves to produce the progressive
heating of the combustible in the front furnace, and, further, it serves to present
incandescent coke to the passage of the mixture of air and combustible gases which
it ignites at the mouth of the combustion nozzle of the front furnace. Its position,
as regards the back furnace, is such that it allows the layer of incandescent com-
bustible to be tapered away to nothing at its contact with the bridge, not only
without incurring the risk of its being extinguished, but, on the contrary, increasing
the activity of the combustion in the back furnace, becanse the latter is constantly
fed by the furnace proper and its temperature is constantly maintained by that of
the furnace proper where there is always a large quantity of fuel. It serves, finally,
for radiating on the arch which closes in the back furnace and which must be
maintained at a red heat.
Referring to Fig. 15-The back furnace which adjoins the actual furnace is
essentially composed of a combustion inlet or nozzle m for the gases of the front
furnace, of a movable grate f, of a bridge n, of a part for throwing down the flame
with an arch t for radiating the heat of a special air inlet o under the movable
grate with a regulating register U and of an oscillating or other register U³
separating the ash pan of the back furnace from that of the furnace proper.
The combustion nozzle m for the gases of the front furnace is placed at such a
point that the gases shall be able to pass exactly between this point, or more
exactly the line that it forms with the arch of the furnace, and the surface of the
incandescent fuel without spoiling the draught. This point forms the entrance of
the back furnace.
This entrance is generally formed like a bridge with an air collector to preserve
it from too rapid a deterioration. The entrance of the back furnace has the
essential effect :-
1. Of forcing the mixture of air and gas coming from the front furnace to pass
down as close as possible to the incandescent fuel on the grate of the furnace
proper.
2. Of introducing air in excess on to the incandescent fuel at the point where it
is the thickest and highest, at the entrance of the back furnace and, consequently,
at the point where the most carbonic oxide is produced; and
3. Of producing the intimate mixture of the same by throwing them down, then
to produce the combustion of the mixture by forcing it to pass in proximity to
the incandescent coke. According to whether the bridge n of the back furnace is
more or less elevated with the entrance inlet always lowered to the maximum
extent, the flame may be more or less deflected, which may, however, always be
limited by the construction of the arch t for throwing down the flame, and by the
necessities of the installations. How its action, combined with that of the air inlet
under the grate of the back furnace, allows the total combustion of the combustible
B

page_text: gases to be completed, which may have escaped combustion on the incandescent
coke, will be described further on.
The movable grate f of the back furnace is composed of bars, the forms and
sections of which are suited to the nature of the fuel, but connected among them-
selves in such a way that all the grate, as a whole or part thereof, may turn on an
axis, being caused to move by means of levers p p.
The grato is arranged in such a way that one of ite extremities ends at the
natural line of slope of the incandescent fuel, at its exit from the front furnace.
This grate may terminate at its upper end in a hook or catch which will retain
the combustibles and will render the working of the movable grate more exact, as
regards the introduction of air into the back of the furnace for the purpose of
effecting the total' combustion of the carbonic oxide. But the movable grate of
the back furnace may, at the same time, serve to cause the cinders contained in the
incandescent fuel to fall out. For that purpose, it is sufficient to give a back and
forward motion to the grate by means of levers which act directly on the axis of
the grate or otherwise. In this way, either the whole or a part of the grate of
the furnace proper b may be made to move at the same time by causing it to come
in contact with the extremity 'of the movable grate.
The axis of the movable grate is made of large dimensions in order to increase
as much as possible its conductibility, and it rests at each side on strong metallic
pieces 1, 2, Figures 15 and 16, which may be cooled either by means of a current
of cold air supplied by the pipes 3 and 4, or with a stream of water in order to
cool the movable grate by a lateral cooling and by 'conductibility, one of the
pipes 4; which is reserved for the passage of air, 'may be employed for the passage
through it'of the handle arm 5 of the lever which actuates the movable grate. The
grates of the front furnace, and of the furnace proper, may also be cooled by the
circulation of' water. This water then flows into the ash pan, as is frequently
the practice.
1
The bridge n would not exhibit anything particular if it did not, in this arrange-
ment of back furnace, become the auxiliary of the movable grate, in order to
allow a greater or smaller current of air to penetrate perpendicularly, to the
direction of the combustible gases, by means of a channel or passage o (Figure 1)
which distributes the air under the grate of the back furnace. It may be con-
structed in any known way and with or without air circulation, as may be required
and to aid in the deflection of the flame.
The dome of the back furnace, for deflecting the gases and for effecting the
radiation of the heat, is arranged so as best to fulfil these two purposes in view of
its application 'and-needs, and, as far as possible, in such a way as to cause the
heat to radiate at the point where the mixture of air and gas is the greatest.
.
The object of the deflection of the flame is to complete the mixture of the air
and the combustible gases,' and that of the vault to complete the combustion of the
mixture.
The air inlet is one of the essential parts of the back furnace, it is placed
below the grate of the same and preferably across all the width of the wall of the
bridge. It receives a certain amount of air either from the air collector or direct
from the outside by means of spécial pipes fitted with regulating registers. The
important role of this air inlet will be explained later on..
The admission of air' into the back furnace is simultaneously regulated with the
admission of air 'under the grate of the furnace proper by means of a register r
placed in the door of the ash box, as well as by the thickness of the fuel, which
may be regulated by, inclining more or less the grate of the ordinary furnace, the
penetration of the air being produced in a manner inversely proportionate to the
thickness! The air, if desired, may be divided between the-grates of the two
furnaces by means of the movable partition U placed between the ash box of the
furnace proper and that of the back furnace.
The air collector (Figures 1 and 2) placed at the entrance of the back

page_text: furnace, or in the upper part of the bridge, also sends warm air by a pipe placed
in the bridge under the grate of the back furnace. A portion of the air of this
collector may be sent to the gas combustion nozzlo of the front furnace, or to any
other suitable place in industrial furnaces especially. Such inlets of air may also
be regulated by suitably placed registers. In Figure 15, the warm air which
reaches o is brought from the outside by the conduit X and from thence to X!,
and' is then discharged at under the movable grate of the back furnace. Figure 18
shows a separate view of these passages. x is the external regulating plug of
this pipe X.
The back furnace, such as herein before described, acts by itself burning directly
in carbonic acid the incandescent coko which exists therein in a thin layer, under
the action of a quantity of air in excess. But, in addition, the back and front
furnaces exert together a final combined action for completely burning the
carbonic oxide which is formed on the thick layer of incandescent coke of the
furnace proper, and of a part of the front furnace, together with the combustible
gases which have escaped from the necessary incomplete distilling action of the
front furnace, togther also with the molecules of carbon which are the con-
sequence of an incomplete combustion.
A certain quantity of air in excess is allowed to enter by the register of the
front furnace, which is forced to follow the wall of the arch of the furnace,
and comes above the back furnace in a thin layer of air which is heated
more and more, and which, not having encountered any resistance, has a
considerable speed. In the same way, the air, which entered by a special
inlet under the grate of the back furnace, as much against the wall of the
bridge as possible, and across all the width of the furnace presents itself
on arrival în a more or less heated layer, which is further re-heated by
flowing over the surface of the wall of the bridge, and which, as it does not
encounter any resistance, is endowed, like the former current, with a relatively
great rapidity, and is delivered perpendicularly to it.
The combustible gases and the molecules of carbon emanating from the surface
of the fuel are drawn by the draught towards the right angle formed by the
moving layers of air which compress them between them when they meet according
to the resultant of their two perpendicular directions, precisely at a very hot part
of the furnace. under the arch which receives all the radiation of the incandescent
coke in the furnace proper. All the volatile substances, thus compressed in a
double current of air, burn in a similar way to what a Bunsen burner would do,
entirely without smoke, and further contribute in maintaining, at the exit of the
back furnace, the highest temperature of the whole furnace.
The different industrial furnaces as above have been so described under the
supposition that they worked always with an oxidising flame producing carbonic
ncid in order to yield the most complete combustion, but, in certain cases, it may
be necessary to cause the furnace to work otherwise, for instance, in the case of a
steam boiler, if the temperature is too high at the point of contact with the fire, or
in the case of pottery furnaces. For this purpose, a portion of the warm air, which
is usually caused to enter under the back furnace, diverted and is directed by
means of a pipe and a valve suitably placed, see Figures 15 and 18, at the
extremity of the first contact point of the fire, to a point capable of still heating a
brick to redness, and, at this point, a fire brick arch is formed which forces the
current of the products of combustion to pass downwards. A groove may be made
at this point, if necessary, in the bottom of the Hlue in order to leave a sufficient
width for the passage of the products of combustion.
In pottery furnaces, when the first half of the furnace is brought to an
incandescent redness, this first part may act in a similar manner to the arch-above
mentioned, and, by bringing the necessary air to this point whilst the furnace is
being worked with carbonic oxide, a second centre of combustion is obtained,
which serves to facilitate the second part of a baking in the furnace.
Among the different parts which have been just described; some which exist and

page_text: 1
are shown in Figures 1 to 6 are not found in Figures 7 to 12, where they would be
useless or superfluous. In exchange for that, there are found some details such as:-
A regulating valve ja fixed on the door of the ash pan or otherwise, and
intended to allow the air to penetrate under the furnace proper;
An opening m for the escape of the smoke;
A fire clay fire plate o;
A damper fitted with a handle & ;
A pastry oven n, a boiler p, a stove (drying chamber) 7, a coal box and
rods for regulating the valve (Figures 7, 8 and 9);
An inlet for the admission of fresh external air n", a casing g" forming an air
chamber, and a closing device p" of the charging hopper.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that I wish
it to be understood that the shapes, dimensions, proportions and accessory parts of
the various constituent parts of this new arrangement of- furnace and the materials
to be used in their construction or erection may be varied as may be considered
suitable without departing fron the principle of my invention, but that what I
claim is :-
1. The improved arrangement of furnace whereby complete combustion is.
produced, consisting in the combination of a front furnace, of a furnace proper and
of a back furnace, the shape and dimensions of which vary with the fuel to be
consumed, and composed of chambers in which the air necessary for combustion
may be allowed to enter by means of nozzles, grates or air passages of shapes and
dimensions suitable for the combustible, the latter being itself-retained or supported
as the case may be by means of bars of variable form according to the degree of
fineness of the fuel, all substantially as described in the above Specification and
shown on the accompanying drawings.
2. As a part of the improved arrangement of furnace, a space or chamber which
is called the "front furnace," in which the distillation of the gases from the
fuel takes place, together with their admixture with air, in proportion as they are
produced by the progressive heating of the fuel, the removal of the mixture and its
deflection in the draught chamber and which chamber ends in a combustion nozzle
over the incandescent coke.
It is this part of the apparatus more particularly in which what is commonly
called smoke consuming is produced. It is formed of a space enclosed on the one
band by a chamber for the admission of air having a register at one side and grate
bars on the other of various shapes and positions according to the condition of the
fuel, arranged vertically or horizontally and supplied or not with air and gas
conductors, regulated themselves, if necessary, by registers, the object of which is
to allow the air to penetrate the mass of the fuel whilst holding up the latter if
required, and to facilitate the mixture of the air and gases and the removal of
such mixture; and, on the other hand, by a counter grate also. of variable form
allowing the mixture of air and gas to pass into the exit chamber from whence it
is carried by the action of the draught to the furnace proper; especially the use
in the front furnace of bars in the shape of gutters for the purpose of burning solid
fuel in the front furnace, substantially as described in the above Specification and
shown on the accompanying drawings.
3: As a part of this improved arrangement of furnace, a space or chamber which
may be called the "furnace proper,” and which in fact is nothing else but an
ordinary furnace but occupying, in the combination constituting this arrangement,
a special position in relation to the front and back furnace from whence the accom-
plishment of particular phenomena in the combustion results, substantially as
described in the above Specification and shown as a specimen on the accompanying
drawings.
4. As a part of the improved arrangement of furnace, a space or chamber which
may be called the "back furnace," in which the combustion is terminated' and

page_text: completed, composed of a chamber enclosed, on the one hand, by the furnace
proper, on the other by the bridge and dome adjoining thereto for deflecting the
Hame and having at its lower part bars serving to hold up the fuel whilst burning,
presenting necessarily to the depth of the fuel a triangular section the base of which
is attached to the furnace proper, whilst the summit, at the opposite end of the
bars, is attached to the side of the bridge, these bars forming a grate, to which a
back and forward movement may be given for the purpose of shaking up the fuel,
and increasing the passage of the air supplied from an oscillating or other register
which distributes it as required under the furnace grate or that of the back furnace,
the said back furnace being further completed by a special air inlet placed below
the grate of the back furnace and regulated by means of a lever which allows of the
movable grate being more or less inclined, and further by means of registers for
admitting and dividing the air, substantially as described in the above Specification
and shown on the annexed drawings.
5. As a part of this new arrangement of furnace, in addition to the air and gae
conductor described in Claim 2, the counter grate in the form of an undulated
partition allowing the draught to act on the mixture of the gases and air and on the
products of combustion with increasing efficacy as the undulations are made more
pronounced, and thus present a greater development of walls of small resistance and
even chambers for disengaging the gases, having, if necessary, a circulation of air
or water, and external doors allowing for inspection, repairs or replacement of
parts, substantially as described above and shown on the accompanying drawings.
6. As a part of this new arrangement of furnace, a counter grate formed of bars
for the purpose of holding up the fuel on its line of slope, and forming part of the
dome proper of the furnace from which it is separated by apertures, grooves or
intervals intended to allow of the escape of the mixture of gases, or the return of
the flame, substantially as described in the above Specification and shown as a
sample on the accompanying drawings.
7. In combination with this arrangement of furnace, the use of air and gas con-
ductors in the bars of the furnace grate, in the form of projections in order to
introduce air into the same while holding up the fuel, substantially as described in
this Specification and shown on the annexed drawings.
8. A furnace intended to consume dust especially coke dust, consisting of the
combination of the grate of the back furnace with that of the furnace proper,
substantially as described in the above Specification and shown on the annexed
drawings.
9. In combination with the back furnace forming a constituent part of this new
arrangement of furnace, the use of a movable grate, the special function of which
consists in obtaining the complete combustion into CO (of the carbonic oxide
produced in the furnace proper), and for this purpose in forcing the thickest part
of the fuel to assume a triangular form, that is to say, to be of no depth at
the extremity of the grate, allowing of the introduction of air at both ends of this
grate in greater or less quantity according to the inclination given to the grate in
question and the acration of the whole mass of fuel on the grate by the back and
forward motion which is given thereto. This oscillating motion may also be imparted
simultaneously to the grate of the furnace proper, by the contact of the latter with
the movable grate of the back furnace, the axis of rotation of this movable grate
and the lateral supports which hold it up being formed of strong pieces allowing
their conductibility to be increased and capable of being cooled by simple air inlets
formed laterally in the masonry or by the circulation of water laterally, which can
then be used to supply the ash pan, or for any other purpose, substantially as
described in the above Specification and shown in the annexed drawings,
10. In combination with the back furnace forming a constituent part of this new
arrangement of furnace, the use of a bridge in which a current of more or less
heated air may circulate coming from the counter grate or from a lateral pipe
adjoining the latter, which current of hot air may either pass down below the grate
of the back furnace, and thus serve to complete the entire transformation of the

page_text: combustible gases into carbonic acid, that is to say, to produce as perfect a com-
bustion as possible, or may be conveyed wholly or partially to any other part of
the grate, in order to complete at that point the combustion of that part of the gas
which is carried off as carbonic oxide, substantially as described in the above.
Specification and represented on the accompanying drawing.
11. In combination with this new arrangement of furnace, the use of valves or
registers dividing the ash pan and their prolongations in various parts, allowing the
air to be divided according to the respective requirements of the furnace proper
and the back furnace, substantially as described in the above Specification and
represented as an example on the accompanying drawings.
Dated this 1st day of April 1892.
WM. P. THOMPSON &. Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.