Furnaces and Fire-places.
Year: 1886

page_text: Date of Application, 24th June, 1886.
Complete Left, 24th Mar., 1887.
Complete Accepted, 26th Apr., 1887.
in Furnaces and Fire-places.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of 53,
Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents,
do hereby declare the nature of this Invention to be as follows:-
This Invention has for its object to effect the more perfect utilization of the
combustible gases in furnaces generally including those of stationary, locomotive,
portable, and marine engine boilers, as well as domestic fireplaces, by the introduction
of air into the chimney or furnace in regulated quantity; the Invention including the
arrangements by which the air is distributed in a rational manner upon the surfaces
on which it is to act. The results obtained by this Invention are ;
(1) Perfect consuinption of the smoke.
Considerable saving in fuel in consequence of the inore perfect combustion, and a
better utilization of the gases.
(3). When the air is introduced into the furnace itself the air is passed through bars
of special form whereby the preservation of the grate is ensured.
In order that the Invention may be more readily understood, I will proceed to
describe examples of its application with reference to the accompanying drawings
which show the particular arrangements adopted for each kind of furnace and which
are based on the following principle ;-The air is drawn from the exterior by the
draft resulting from the difference between the external and internal temperature of
the chimney or furnace, the air being first heated by contact with the walls of the
passages and then being drawn therethrough and caused to mingle with the hot gases.
The air thus introduced produces a mechanical action the effect of which is to carry off
the lighter gases completely burnt and to retard the escape of the heavier gases yet.
unconsumed which remain in suspension in the furnace until their complete combustion
Dovice 1117

page_text: is effected. In this manner combustion of smoke is effected by the carrying off of
none but the lighter gases completely burnt and a considerable saving of fuel is
obtained by the retention of the heavier gases whose complete combustion is thus
secured.
In the arrangement shown in vertical section, elevation, and plan, in figures 1, 2, 3,
the air drawn in at the orifices 'A in the external casing of the chimney, first passes
down the external annular space E between the double walls of the casing, and then
up through the internal annular space D and escapes at O into the chimney at a very
high temperature and therefore at a considerable pressure. The inner pipe F may be
made vertically adjustable in any suitable manner for the purpose of increasing or
reducing the area of the aperture and thus regulating the admission of the external
air. The external surface of chimney F being in contact with the air introduced at a
relatively low temperature and the internal surface being licked only by the gases of
combustion which are not yet mixed with the air introduced, there would be throughout
the entire length of this tube F a less perfect combustion than at the upper part at
which the air acts, and a considerable quantity of soot would consequently be liable to
collect upon the inside surface of the chimney which would prevent the transmission
of heat and therefore diminish to a corresponding extent the temperature of the air.
introduced and the rate at which it passes into the chimney. To obviate this objection
a shaft I provided. with blades R is placed. in the chimney F for the purpose of
scraping the sides thereof so as to. cause the soot to fall to the bottom whence
removed at a door M. provided for the purpose.
is
The same principle may be applied to the chimneys of marine engine boilers the
arrangement adopted being that represented in part sectional elevation and horizontal
section in figures 4 and 5. The air in these figures takes the same direction as in
figures 1 2 and 3 entering at the orifices A traversing the annular space E and then
through the several annular spaces D until it reaches the chimney. As, however, the
total sectional area of the chimney would be very considerable and the air would
naturally tend to pass through the passages nearest to the air inlet, the central flues
might receive an insufficient quantity of air for the proper working of the apparatus.
To obviate this, supplementary air passages D¹ opening near the base of the chimney
are placed within the flues D and are so arranged and distributed as to create a strong
draft and cause the air to be distributed uniformly in all the passages D., The air as in
the preceding arrangement, on leaving passages D enters the chimney through the
annular orifice O. The flues F may be. cleaned out, in the same manner as, in the
previous arrangement and with a similar object.
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The arrangement preferably employed for the factory shafts is shown in figures 6
and 7 as applied to an ordinary chimney and in figures 8 and 9 as applied to a
chimney of larger diameter. The principle is the same as- before, but in this case a
series of cylindro-conical superposed tubes are employed. The action is exactly the
same as in the previous cases and therefore needs no further description. It should
however be added that in order to regulate the draft, that is to say, the area of the
orifices adjusting screws are employed by which the pipe F may be raised or
lowered for increasing or reducing the size of the orifice as desired. The cleaning is
effected by means of a pulley and chain worked from the base of the chimney, the
operation being repeated more or less often according to the-quality of the fuel
employed. In order that the hot gases arriving from flue F. may pass direct to
the centre of the chimney Fa sort of bridge of refractory material P is placed at the
mouth of said flue which diverts the course of the gases and causes them to take the
direction desired. The same arrangement may be applied to chimneys of large
diameter such as represented in figures 8 and 9 and in order to distribute the current
of air over its whole area one or more central draft tubes D¹ similar to those for
the chimney's of marine boilers may be employed. Mare doors for cleaning out the
.flues.
Figures 10 and 10 represent an arrangement specially adapted to house chimneys
and in order in this case, that the air may enter the chimney at a sufficiently high
temperature, its contact with the heated inner wall of the annular space D'is prolonged

page_text: as much as possible by a spiral rib N formed upon the tube I and extending to
the external wall of the annular casing D. The air entering the annular space D
thus takes a spiral course and escapes as in the preceding arrangements at the annular
orifice O where it becomes mixed with the hot gases and produces the upper draft.
C is a tubular cast iron socket which is let into the brickwork in the place of
the chimney-pot. The pipe may be hinged at its bottom end G so as to enable it
to be lowered down.
Figures 11 and 12 illustrate the application of the Invention to the chimney of a
portable or locomotive engine. In this case, the smoke box itself forms the inner
wall of the annular space D into which the external air is admitted through the
openings A. The external envelope of the annular space! 1) is formed by a metal
casing placed eccentrically in the smoke-box. The air in escaping from space D where
it becomes heated passes as before through the orifice O into the chimney and
increases the draft at the upper part. In this case the arrangement represented in
figure 15 may also be employed wherein the air enters at A into a passage above
the smoke box whence it is uniformly distributed by means of vertical flues D to the
chimney and produces the effect above mentioned. In this as in the other applications
the passage for the gases or smoke may be divided into any suitable number of
compartments, and tubes may also extend from top to bottom of the fire box which
take in air from the exterior and serve as feeders for distributing the air to the
compartments, suitable dampers being also provided to increase or moderate the
draft of the furnaces.
It is essential in all cases that the air should be introduced at as low a temperature
as possible compared with that of the gases in the chimney so that it inay expand as
much as possible and thus produce a more considerable effect.
For chimneys of large diameter it is of advantage to employ the arrangement
represented in vertical section in figure 13 and in horizontal section in figure 14. The
chimney is divided into four compartments by vertical division plates a having
perforations communicating with the outer air by channels at their lower end.
The channels & conduct the air heated by contact with the surfaces into the intermediate
space where it acts on the gases in the manner before explained. The chimney is
provided with a double casing ef between which also the air enters at the lower end
and passes out through the inclined passages into the chimney. The casing e is
provided with a conical top forming with the casing a crown i which admits of
air being introduced from the outside and of its circulating between the two casings el f
whence it passes to the upper part of the chimney, to there effect the complete
extraction of the lighter gases and enable the combustion of the heavy gases to be
completed.
In order to preserve the grate bars while at same time effecting the complete
combustion of the gases, produce a higher temperature, economize fuel, and consume
the smoke, the arrangements represented in figure 16 and following figures are
employed which are applicable to the grates of all kinds of furnaces such as metal-.
lurgical, boiler, locomotive, and other furnaces. Figure 16 is a vertical section of
the furnace of a horizontal stationary boiler figure 17 a horizontal section taken on
line 1 2 3 4, and figure 18 an end elevation of the same. Fig. 19 is a longitudinal
section of a locomotive furnace. Figure 20 a vertical section of the same taken on
line 5-6 and figure 21 a horizontal and transverse section of a pair of grate bars drawn
on a larger scale.
In figures 16 17 and 18 a is the boiler shell, the fire box, c pendent water-tubes,
d the steam dome, and e the boiler tubes. The firegrate has hollow bars which
communicate at one end with a pipe g curved to the circular form of the boiler front;
the other ends of the hollow bars communicate with a chamber comprised between
a vertical partition plate, and the back of the fire box. The collecting pipe y is
bent downwards at the ends so as to form tubular legs k, which are provided with
valves, cocks, dampers, or other regulators 1. Cold air enters at the legs & under the
control of the valves, and traverses the whole of the hollow grate bars as indicated by
the arrows where it becomes heated and expanded and enters the collecting chamber h

page_text: whence it escapes by one or more openings m and mixes with the products of
combustion which become completely utilized.
In figures 19 20 and 21 the principle is similar but the fire bars are different in
their form and arrangement. In these figures a is the boiler shell, the tubes, c the
fire box, and the ash-pit. The fire bars are made hollow as before but divided
longitudinally by a partition e into upper and lower passages communicating at one
end as in figure 19 and the lower passage projecting beyond the fire box, the inlet
thereto being controlled by a valve g operated from the foot plate by a rod i k or other
means. The cold air entering at g traverses the bars to and fro as shown until it
reaches the collecting chamber . The expanded air collected from all the bars passes
out at the upper part of chamber k through one or more openings where it mixes
with the products of combustion before they pass out of the fire-box. In this manner
complete combustion is ensured, and the production of smoke avoided. As seen in
figure 21 the bars fare placed in pairs side by side, and along their upper part at
regular distances apart are formed lateral openings m gradually increasing in size
towards the point of greatest incandescence, so as to equalize the production of heat
over the whole arca of the furnace and permit of a certain portion of the expanded air
escaping into the midst of the mass of fuel. These openings m are inclined and the
motion of the engine causes a current of air to be injected in the form of crossed jets
which by intermingling in the midst of the fuel render its combustion more perfect.
The bars may in some cases be pivoted at any suitable point of their length so as to
admit of their being rocked by any suitable means for the purpose of preventing the
formation of clinkers.
It will be readily understood that the forms, dimensions, and details of these hollow
fire bars and collecting tubes may be considerably varied according to the nature of
each application without in any way departing from the principle of the Invention and
they may
also be applied to furnaces generally.
Datad thin with day of Tuus 1001
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: in Furnaces and Fire-places.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of 53,
Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents,
do hereby declare the nature of this Invention (a communication to me from abroad
by Georges Eugène Wéry of 20 Rue Bayen, Paris, France, Engineer), and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:
This Invention has for its object to effect the more perfect utilization of the
combustible gases in furnaces generally, including those of stationary, locomotive,
portable, and marine engine boilers, as well as domestic fireplaces, by the introduction
of air into the chimney or furnace in regulated quantity, the Invention including the
arrangements by which the air is distributed in a rational manner upon the surfaces
on which it is to act.
The results obtained by this Invention are ;
(1) Perfect consumption of the smoke.
(2) Considerable saving in fuel in consequence of the more perfect combustion, and
a better utilization of the gases.
(3) The preservation of the grate bars when the air is introduced into the furnace
itself, by causing the air to pass through bars of special construction.
In order that the Invention may be more readily understood, I will proceed to
describe examples of its application with reference to the accompanying drawings
which show the particular arrangements adopted for each kind of furnace and which
are based on the following principle. The air is drawn from the exterior by tho
draft resulting from the difference between the external and internal temperatures of
the chimney or furnace, the air being first heated by contact with the walls of the
passages and then being drawn therethrough and caused to mingle with the hot gases.
The air thus introduced produces a mechanical action, the effect of which is to carry
off the lighter gases completely burnt and to retard the escape of the heavier gases yet
unconsumed which remain in suspension in the furnace until their complete combustion
is effected. In this manner, combustion of smoke is effected by the carrying off of
none but the lighter gases completely burnt, and a considerable saving of fuel is
obtained by the retention of the heavier gases whose complete combustion is thus
secured.
In the arrangement shewn in vertical section elevation and plan in figures 1, 2,
and 3, the air drawn in at the orifices A in the external casing of the chimney first
passes down the external annular space E between the double walls of the casing and
then up through the internal annular space D and escapes at O into the chimney at a
very high temperature and, therefore, at a considerable pressure. The inner pipe F
may be made vertically adjustable in any suitable manner for the purpose of
increasing or reducing the area of the aperture O and thus regulating the admission

page_text: of the external air. The external surface of chimney F being in contact with the
air introduced at a relatively low temperature and the internal surface being licked
only by the gases of combustion which are not yet mixed with the air introduced,
there would be throughout the entire length of this tube F a less perfect combustion
than at the upper part at which the air acts and a considerable quantity of soot would
consequently be liable to collect upon the inside surface of the chimney which would
prevent the transmission of heat and therefore diminish, to a corresponding extent,
the temperature of the air introduced and the rate at which it passes into the chimney.
To obviate this objection a shaft I provided with blades R is placed in the chimney F
for the purpose of scraping the sides thereof, so as to cause the soot to fall to the
bottom whence it is removed at a door M, provided for the purpose.
The same principle may be applied to the chimneys of marine engine boilers, the
arrangement adopted being that represented in part sectional elevation and horizontal
section in Figures 4 and 5. The air, in these figures, takes the same direction as
in figures 1, 2, and 3 entering at the orifices A traversing the annular space E and
then through the several annular spaces D until it reaches the chimney. As,
however, the total sectional area of the chimney would be very considerable and the
air would naturally tend to pass through the passages nearest to the air inlet, the
central flues might, if not entirely deprived of air, still receive an insufficient
quantity for the proper working of the apparatus. To obviate this, supplementary
air passages D¹ opening near the base of the chimney are placed within the flues D
and are so arranged and distributed as to create a strong draft and cause the air to
be distributed uniformly in all the passages D. The air, as in the preceding
arrangement, on leaving passages Denters the chimney through the annular orifice 0.
The flues may be cleaned out in the same manner as in the previous arrangement
and with a similar object.
+
The arrangement preferably employed for factory shafts is shown in figures 6 and 7
as applied to an ordinary chimney, and in figures 8 and 9 as applied to a chimney of
larger diameter. The principle is the same as before, but in this case a series of
cylindro-conical superposed tubes are employed. The action is exactly the same as
in the previous cases and therefore needs no further description. It should, however,
be added that in order to regulate the draft, that is to say, the area of the orifices O,
adjusting-screws are employed by which the pipe F may be raised or lowered for
increasing or reducing the size of the orifice, as desired. The cleaning is effected by
means of a pulley and chain worked from the base of the chimney, the operation being
repeated more or less often, according to the quality of the fuel employed. In order
that the hot gases arriving from flue F may pass direct to the centre of the chimney F,
a sort of bridge of refractory material P. is placed at the mouth of said flue which
diverts the course of the gases and causes them to take the direction desired. The
same arrangement may be applied to chimneys of large diameter, such as represented
in figures 8 and 9, and in order to distribute the current of air over its whole area
one or more central draft tubes D₁ similar to those for the chimneys of marine
boilers previously described, may be employed. M are doors for cleaning out the
flues.
Figures 10 and 10¹ represent an arrangement specially adapted to house chimneys,
and, in order, in this case, that the air may enter the chimney at a sufficiently high
temperature, its contact with the heated inner wall of the annular space D is prolonged
as much. as possible by a spiral rib N formed upon the tube L and extending to the
external wall of the annular casing D. The air entering the annular space D thus
takes a spiral course and escapes, as in the preceding arrangements, at the annular
orifice O. where it becomes mixed with the hot gases and produces the upper draft.
Cis a tubular cast iron socket which is let into the brickwork in the place of the
chimney pot. The pipe may be hinged at its bottom end G, so as to enable it to
be lowered down.
Figures 11 and 12 illustrate the application of the Invention to. the chimney of a
portable or locomotive engine. In this case, the smoke-boxitself forms the inner
wall of. the annular space D into which the external air is admitted through the

page_text: openings A. The external envelope of the annular space D is formed by a metal
casing placed eccentrically in the smoke-box. The air in escaping from space D'whero
it becomes heated passes, as before, through the orifice O into the chimney and
increases the draft at the upper part. In this case; the arrangement represented. in
Figure 15, may also be employed wherein the air enters at A into a passage above the
sinoke-box whence it is uniformly distributed by means of vertical flues D) to the
chimney and produces, the effect above mentioned. In this as in the other applications,
the passage for the gases or smoke may be divided into any suitable number of
compartments and tubes may also extend from top to bottom of the fire-box which
take in air from the exterior and serve as feeders for distributing the air to the
compartments, suitable dampers being also provided to increase or moderate the draft
of the furnace.
It is essential, in all cases, that the air should be introduced at as low a temperature
as possible compared with that of the gases in the chimney, so that it may expand'as
much as possible and thus produce a more considerable effect.
For chimneys of large diameter, it is of advantage to employ the arrangement
represented in vertical section in figure 13 and in horizontal section in figure 14. The
chimney is divided into four compartments by vertical division plates a having
perforations communicating with the outer air by channels c at their lower end.
The channels conduct the air heated by contact with the surfaces into the inter-
mediate space where it acts on the gases in the manner before explained.. The
chimney is provided with a double casing ef, between which also the air enters at
the lower end and passes out through the inclined passages into the chimney. The
casing e is provided with a conical top k forming with the casing a crown i which
admits both of air being introduced from the outside and of its circulating between
the two casings e f¹ whence it passes to the upper party of the chimney, to there
effect the complete extraction of the lighter gases and enable, the combustion of the
heavy gases to be completed.
In order to preserve the grate bars while at same time effecting the complete
combustion of the gases, produce a higher temperature, economize fuel, and consume
the smoke, the arrangements represented in figure 16 and the following figures are
employed, which are applicable to the grates of all kinds of furnaces, such as metal-
lurgical, boiler, locomotive, and other furnaces. Figure 16 is a vertical section of the
furnace of a horizontal stationary boiler, figure 17 a horizontal section taken on
line 1-2-3-4, and figure 18 an end elevation of the same. Figure 19 is a longitudinal
section of a locomotive furnace. Figure 20 a vertical section of the same taken on
line 5-6, and figure: 21 a horizontal and transverse section of a pair of grate bars,
drawn on a larger scale.
In figures 16, 17, and 18, a is the boiler shell, the fire box, e pendent water-tubes,
d the steam dome, and e the boiler tubes. The fire-grate has hollow bars which
_ communicate one end with a pipe g curved to the circular form of the boiler front,
and at the ér end with a chamber comprised between a vertical partition plate i
and the back of the fire box b. The collecting pipe g is bent downwards at the ends,
so as to form tubular legs which are provided with valves, cocks, dampers, or other
regulators. Cold air enters at the legs under the control of the valves, and
traverses the whole of the hollow grate bars, as indicated by the arrows, where it
becomes heated and expanded and enters the collecting chamber whence it escapes
by one or more openings m and mixes with the products of combustion which become
completely utilized.
In figures 19, 20, and 21, the principle is similar but the fire bars are different in
their form and arrangement. In these figures, a is the boiler shell, the tubes,
c the fire box, and d the ash-pit. The fire bars are made hollow as before, but
divided longitudinally by a partitione into upper and lower passages communicating
at one end, as in figure 19, and the lower passage projecting beyond the fire box,
the inlet thereto being controlled by a valve g operated from the foot plate by a
rodi k or other means. The cold air entering at traverses the bars to and fro, as
shewn, until it reaches the collecting chamber k¹. The expanded air collected from

page_text: all the bars,, passes out at the upper part of chamber through one or more
openings where it mixes with the products of combustion before they pass out of
the fire-box. In this manner, complete combustion is ensured and the production of
smoke avoided. As seen in figure 21, the bars fare placed in pairs side by side, and
along their upper part, at regular distances apart, are formed lateral openings m
gradually increasing in size towards the point of greatest incandescence, so as to
equalize the production of heat over the whole area of the furnace and permit of a
certain portion of the expanded air escaping into the midst of the mass of fuel. These
openings are inclined, so that the motion of the engine causes a current of air to be
injected in the form of crossed jets which, by intermingling in the midst of the fuel,
render its combustion more perfect. The bars may, in some cases, be pivoted at any
suitable point of their length, so as to admit of their being rocked by any suitable
means, for the purpose of preventing the formation of clinkers.
It will be readily understood that the forms, dimensions, and details, of these hollow
fire bars and collecting tubes may be considerably varied according to the nature of
each application, without in any way departing from the principle of the Invention,
and they may also be applied to furnaces generally.
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 what 1 claim is;-
1st. The combination with furnaces and chimneys of all kinds, of air passages by
which a natural draft of air is admitted from the exterior into the midst of the hot
gases, said passages being so arranged as to prolong the traverse of the air sufficiently
to cause it to become gradually heated by contact with the walls of the passages, and
the passages being also contracted at the point where they open into the furnace or
chimney, so as to increase the velocity of the draught at this point all as herein-
before described and illustrated in the drawings, and for the purposes specified.
2nd. The employment of hollow grate bars in which air is caused to circulate and
expand, as herein described, and of one or more collecting chambers in which the
expanded air is received and conducted into the fire box, as described and represented
in figurés 16, 17, 18, 19 20, and 21 of the drawings, for the purposes specified.
Dated this 24th day of March 1887.
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.