IM- PROVEMENTS IN FURNACES FOR PROMOTING THE COMBUSTION OF FUEL WITHOUT SMOKE, AND THE COMMUNICATION OF HEAT, SPECIALLY ADAPTED TO STEAM BOILERS
Year: 1857

page_text: LETTERS PATENT to Daniel Kinnear Clark, of 11, Adam Street, Adelphi,
in the County of Middlesex, Civil Engineer, for the Invention of "IM-
PROVEMENTS IN FURNACES FOR PROMOTING THE COMBUSTION OF FUEL WITHOUT
SMOKE, AND THE COMMUNICATION OF HEAT, SPECIALLY ADAPTED TO STEAM
BOILERS."
Sealed the 21st May 1858, and dated the 30th November 1857.
PROVISIONAL SPECIFICATION left by the said Daniel Kinnear Clark
at the Office of the Commissioners of Patents, with his l'etition, on the
30th November 1857.
I, DANIEL KINNEAR CLARK, of 11, Adam Street, Adelphi, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN FURNACES FOR PROMOTING THE COMBUSTION OF FUEL
WITHOUT SMOKE, AND THE COMMUNICATION OF HEAT, SPECIALLY ADAPTED TO STEAM
BOILERS," to be as follows:-
First, in a method of improving the combustion of fuel and preventing
smoke by projecting jets of steam into the furnace or fire-place; the openings
may be so formed as to spread the jets as they expand, so as by their action
to divert and mix the gases as they rise from the coal, and the jets may be
directed either over or through the fuel.
Second, in a method of accomplishing the same object by projecting jets of
SP 87

page_text: steam through apertures in the sides or other part of the fire-place, so as to
draw air with the steam into the fire-place, and to diffuse it over or through
the fuel, in order to become mixed with the gases as they are generated, and
to burn them. The air and steam inay be mixed previously to entering the
fire-place, if preferred.
Third, in a method of accomplishing the same object by projecting jets of
air into the fire-place overor through the fuel, impelled by forcing apparatus.
Fourth, in further mixing and consuming the gases by projecting steam,
air, or a combination of both, into a mixing chamber, auxiliary to the
furnace, or by the insertion of diaphragms made distinct from the body of
the chamber, and capable of being readily disconnected for repair or reuewal.
Fifth, in a method of economising fuel in locomotive boilers by the appli-
cation of descending flues, forming a heat-trap, through which the products
of combustion are passed previously to ascending into the chimney.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Daniel Kinnear Clark in the Great. Seal Patent Office on
the 29th May 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DANIEL
KINNEAR CLARK, of 11, Adam Street, Adelphi, in the County of Middlesex,
Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of November, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Daniel Kinnear Clark, Her special licence that I, the suid Daniel
Kinnear Clark, my executors, administrators, and assigns, or such others as
1, the said Daniel Kinnear Clark, 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 vond, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN FURNACES FOR PROMOTING THE COMBUSTION OF FUEL WITHOUT
SMOKE, AND THE COMMUNICATION OF HEAT, SPECIALLY ADAPTED TO STEAM BOILERS,"
upon the condition (amongst others) that I, the said Daniel Kinnear Clark,
my executors or administrators, by an instrument in writing under my
or their, or one of their hands and seals, should particularly describe and

page_text: 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 Daniel Kinnear Clark, do hereby
declare the nature of my said Invention, and in what manner. the same
is to be performed, to be particularly described and ascertained in and by
the following statement:-
My Invention relates, first, to certain improvements in furnaces, for
effecting the complete combustion of fuel and the prevention of smoke.
Secondly, to the application of descending flues in locomotive boilers, for
the better absorption of heat from the products of combustion.
With respect to my improvements in furnaces, one or more openings or
passages to the furnace are formed through the sides or other suitable parts
of it, or of adjuncts thereof, in free communication with the atmosphere
for the admission of air; and one or more jets of steam are projected through
these openings, in order to draw the air into the furnace, the action being
like that of the blast in the chimney of a locomotive engine; and to diffuso
and mix the air with the combustible gases as they are generated, and so to
burn them and economise fuel. The jets of steam are employed as instru-
ments, or means of forcibly inducting air into the furnace, and diffusing
and impinging it upon and amongst the gases and the fuel. The steam
inducted air columns or currents may be introduced at any level, and in any
direction, above, through, or beneath the fuel. When introduced at or above
the level of the fuel, they spread over the surface, and smoke is effectually
prevented. When they are directed upon the fuel from above, or into, or
through the fuel, it is raised to a state of intense ignition by the forcible
induction and impingement of air upon it, whilst smoke is thus also prevented,
a considerable proportion of solid fuel is consumed by the inducted air.
The Invention embraces the method of injecting steam alone into fur-
naces through fit jet orifices, in order to spread the steam in sheets over
the fuel and promote combustion.
The Invention consists, further, in methods of delivering air into furnaces
under pressure. First, by discharging air in jets through openings in the
sides or other suitable parts of the furnace, or adjuncts, in free communica-
tion with the exterual air, so that air may be drawn into the furnace in
company with the jets of air, similarly to the action of the steam jets
already described; secondly, by delivering the air in sheets by means of flat
jet orifices. A small proportion of water may, if preferred, be mixed with

page_text: the air, being introduced into the air passages or otherwise. The air inay
be forced into the furnace by any of the ordinary mechanical means.
Steam inducted air currents, or pure air currents, may be delivered in the
methods above described, amongst the combustible gases, in an auxiliary
chamber or chambers, or in the flues apart from or. beyond the furnace, or
in or near the chimney; in order that by themselves; or conjointly with
currents in the furnace, combustion may be promoted and smoke prevented.
In administering air by steam induction, it is desirable that the greatest
quantity of air should be drawn in with the lowest expenditure of steam.
The openings or passages for air may be tubular, conical, bell-mouthed, or
otherwise formed for the free induction of air. The steami jets may be
discharged from round, flat, rifled, or otherwise shaped orifices, so that the
currents may spread conically or in flat fan-like sheets, or spirally, or other-
wise, as may be desired. The passages to the steam-jet nozzles may be of
any form; the pipes or passages should be large enough to carry the steam
to the orifices at or nearly of the same pressure as in the boiler, und the jets
should be delivered from contracted orifices. with taper nozzles, terminating
with the "contracted vein" or other form, suited to deliver the steam fully
and freely. A very powerful draft by steam induction is generated from a
jet orifice, about one-twentieth to one-thirtieth in diameter of the opening or
passage for air; the nozzle being placed at a distance from the smallest
part of the opening, equal to about three to four times its diametor.
[:do
not bind myself by these ratios; the proportions may vary with the pressure
and other circumstances; for instance, the greater the pressure, or the
froer the draft, the smaller may be the jet orifice, and the larger the
opening. In general, the jet should be so placed as, in oxpanding, to block
or fill the opening, and give the longest practicable lead for the jet, that
it may engage and induct the greatest quantity of air..
The currents may be delivered into receiving and distributing chambers
conveniently situated, from which the inducted currents may bo widely dis-
tributed within the furnace through any number of perforations or channels.
By a suitable disposition of cocks, or other appliances, within easy reach of
the engineman or attendant, any one jet, or set or selection of jets may be put
in operation, or disused above, below, or beyond the grate. The power of the
jets in operation may be regulated by the same means or by means of variable
jot orifices like the variable blast pipes of locomotives, or of alternative jets at
the same or at distinct openings. Again, the draft may be accelerated by dis-
charging two or more jets of steam into the same passage or channel, side by
side, as with annular jets like "argand burners;" or, at different points in

page_text: succession, particularly if the passage be of considerable length. The draft
may also be accelerated through the passages by means of entrances to them,
plain, or made with funnels or cowls turned towards the wind.
Figures 1, 2, 3, shew an application of the Invention to a locomotive boiler,
in which steam is taken from the boiler by pipes a to branches b, at different
levels at the sides of the ire box e and the ash-pan f. Tubular openings c are
made through the sides, and jet nozzles are pointed towards these open-
ings, oue to each, to project the currents directly across the furnace. One
or more jets or rows of jets may be turned on, and the inducted currents
delivered at any required level either above or below the grate.
Figures 4, 5, shew another arrangement; steam pipes are laid outside
across the frout and back of the fire box and ash-pan, and the openings are
conical. The jet nozzles d, pertaining to the fire box, are inclined downwards
to throw the currents upon the surface of the fuel, and to extend the range
of their action at varying levels of fuel, as compared with that of currents
delivered horizontally; further, that the currents may more directly impinge
upon and burn the solid fuel as the combustible gases become exhausted.
inducted air being in this way continuously utilised. The jet nozzles per-
taining to the ash-pan are pointed upwards to direct the currents through the
grate; and they afford a means of regulating the supply of air through the.
grate, either with or without the use of dampers at the ash-pan, the
chimney, or elsewhere.
Figure 6 shews an application of downward currents through the upper
part of the fire box, to descend upon the fuel and the gases.
Figures 7, 8, shew an application of flat jets through the back of the fire
box, one at each corner; the openings into the fire box are flattened to match
the jets.
Figures 9, 10, illustrate an application of inducted air currents to a loco-
motive boiler having a combustion chamber. Duplicate nozzles, direct and
inclined, may be applied to each opening, as in Figure 11, and the one or
the other may be put in action as required.
Figures 1 to 11 contain examples of the application of tubular, conical,
and flat openings.
Figures 12 to 10 illustrate other forms of openings, with the disposition
of the nozzles and jets. The jets may be protected from side winds or other
circumstances, within enclosures, one to each jet, perforated or otherwise
formed to pass air freely, as exemplified in Figures 17 to 21; or, they may
be grouped together within larger chambers, as in Figures 22, 23, 24. The
reception of currents in distributing chambers is exemplified in Figures 25,26,

page_text: shewing a single current divided into streamlets, passed through a number
of small passages; also, in Figures 27, 28, illustrating the reception of two
or more currents in one chamber, and their diffusion through a number of
openings.
Figures 29, 30, shew examples of nozzles for round jets.
Figures 31 to 34 shew two varieties of nozzles for flat jets; in the second of
which the jet isdeflected andflattened bya plate which forms partof thenozzle.
Figures 35, 36, shew the jet flattened upon a plate or partition in the
opening Figures 37, 38, shew converging and diverging nozzles, with
adjustable plugs, to regulate the strength of the jets; and they may be formed
to give any degree of divergence; Figures 39, 40, shew an annular nozzle
with two or more jet orifices to draw air internally and externally. The jet
nozzles, singly or in numbers, may be placed on swivelling frames, so that
their level, or their inclination at the same opening may be varied, as in
Figure 41; or, so as to shift them from one opening to another at different
levels, on swivels or on slides as in Figures 42, 43, illustrating the application
of swivels. In the same way, or by similar contrivances, the nozzles may be
shifted laterally, and they may be adjusted to any required distance from the
opening or passage, and the steam may be led to them by flexible tubes. The
adjustablenozzles and steam pipesmay be fixed in position byscrews and sliding
nuts or by ordinary set screws. The nozzles may also be constructed to slide
telescopically towards or from the air openings. The nozzles may be cleared
of obstructions by the application of small cleaning rods or wires fitted
internally so as to slide and be pushed through the orifices of the nozzles
and the cleaning wires may be worked through small stuffing boxes at the
back of the steam pipe by means of a simple mechanical arrangement within
reach of the attendant, as indicated at u, u, Figure 41, and exemplified in
detail in Figure 65; and which may be used also to regulate the strength of
the jet. The action of the inducted currents is assisted by the use of a steam
blow-pipe in the chimney when the steam is shut off from the engine to
draw off the products of combustion. The blow-pipe should havea contracted
nozzle, and in locomotives it may be opened or closed by a simple obvious
connection, simhaneously with the closing or opening of the regulator; the
connection may be made with links, or lovers, or otherwise, capable of
being readily detached or attached.
Figures 44, 45, exemplify the use of my Invention in a marino boiler; the
inducted currents a are introduced at the entrance to the furnace, and deflected
upon and spread over the fuel; the currents are thrown into the ash-pit,and
the currents care inducted into the auxiliary or combustion chamber behind

page_text: the bridge to mix with the smoke as it passes over. The supply of air
behind the bridge is brought from the front under a false bottom plate f,
or it may be brought from above through the pipe or passage d, shown in
dot lining, having a cowl and an auxiliary jet e at the upper end to catch
the wind and promote the draft.
Figures 46 to 50 shew various applications of inducted currents to
stationary boilers in the fire-place and the flues; the air chambers and
passages may be of brick, metal, or other material.
Figures 51, 52, shew the application of the method of inducted air
currents to an ordinary furnace for melting iron.
The foregoing descriptions and illustrations have reference generally to the
method of induction by steam jets; they are intended also to apply to the
method of induction by air jets subject to obvious adaptions, and in the latter
casc a steam rotary reaction engine may be employed to drive a fan on a
common shaft for the supply of air. Though I have, for convenience of illus-
tration, selected the examples of my Invention for promoting the combustion
of fuel without smoke, chiefly with regard to the furnaces of steam boilers,
particularly of locomotive boilers, I do not confine it to any particular class or
classes of furnace. Nor do I confine the application of the details illustrated
and described to any one kind of furnace; details may obviously vary with the
nature and construction of the furnace, but as elucidations of general design
and arrangement, the details are applicable to furnaces generally.
The system of inducted air currents by steam jets or air jets above described
affords a means of throwing air and steam into the furnace without exposure
of any parts to the injurious action of the fire. At the same time it is
applicable to plans for introducing air into furnaces by means of mid-
feathers, arches, tubes, tuyers, partitions, walls, fire bars, or other structures
within or about the fire-place or the flues.
The steam may be obtained from the boiler or from the exhaust passages
of the engine; I prefer steam taken direct from the boiler. The steam or the
inducted current may be superheated prior to its entering the furnace or other
part, if preferred. The supply of steam for the induction of air currents to
furnaces other than those of steam boilers, may be had from any steam
boiler in the neighbourhood, or from a special boiler erected for the purpose.
The steam may be filtered through diaphragms of metallic gauze or other
means, to deliver it free of foreign matter and prevent obstruction of the
nozzles; the steam pipes may be blown through and cleared out through
cocks or plug holes. The steam pipes should be protected by being encased

page_text: in larger pipes, or in felt, or both. The nozzles may be bushed with platinum,
steel, or other suitable material, to prevent wear and culargement. The
method of inducted air currents is serviceable when introduced above the
grate in moderating the draft through the grate, and checking the accumu-
lation of clinker, and in preserving the fire bars. The process is applicable
in the combustion of coal, preventing smoke and promoting economy, and
it also facilitates the use of wood, small or inferior coal or other fuel, so
further promoting economy.
With regard to the second part of my Invention, which relates to the
application of descending flues in locomotive boilers, the products of com-
bustion issuing from the flue tubes are led into and through descending smoke
chambers or flues, after passing through which they ascend into the chimney,
whence they escape in the usual manner. By thus interposing a capacious
descending route, the heating surfaces of the boiler become enveloped in a
bath of the hottest gases, which by their superior levity remain uppermost,
and the relatively cooler gases descend and are drawn off at the bottom of the
descent, and economy of heat and fuel is thus promoted. The descending flue
should be very capacious, so as to allow the gases to circulate freely. Figures
55, 54, shew an application of the descending chamber or flue to a locomotive
engine, in which the capacity and depth of the chamber a within the smoke
box bare shown as great as are consistent with the position of the engine on
the rails; the course of the draft is indicated by arrows. Doors c, d, are
added to clear out ashes, &c., or to open a direct communication with the
chimney, if desired. The Invention is applicable to all boilers of the loco-
motive type.
Having now described my Invention, I may explain that I do not intend to
confine myself to the precise arrangements or details herein-before described
and illustrated, as many variations may obviously be made therefrom, without
departing from the nature and objects of the Invention, and I do not consider
it necessary to enter into details of such modifications; what I believe to be
new and therefore claim as the Invention secured to me by the horein-before
in part recited Letters Patent, according with and having reference to the
descriptions herein-before contained, and the illustrative Drawings therein
referred to and annexed, is as follows:-
First, the forcible induction of atmospheric air into furnaces or into com-
bustion chambers or other adjuncts or flues connected therewith, and the
forcible distribution of the air therein by means of jets of steam for the
combustion of fuel and the prevention of smoke.

page_text: Second, the various forms and proportions of the jet nozzles and the air
openings or passages for the efficient induction of air by the instrumentality
of jets of steam.
Third, the use of one or more receivers or receiving chambers, to receive
and distribute the inducted currents on their way to the furnace, or to its
adjuncts or flues.
Fourth, the use of flat jet nozzles to inject steam alone into furnaces in
flat fan-like sheets over or under the fuel for its combustion, and the
prevention of smoke.
Fifth, the forcible induction and distribution of atniospheric air within
furnaces or their adjuncts or flues, by means of jets of air forced by ordinary
mechanical means, similarly to the method of induction by jets of steam, and
with similar forms and proportions of jet nozzles and air passages, adapted to
the means for the combustion of fuel and the prevention of smoke.
Sixth, the use of mechanical means for working a steam blow pipe in the
chimney, in connection with the regulator or steam valve, specially applicable
to the locomotive engine, with or without the use of special apparatus for
the prevention of smoke.
Seventh, the application of capacious descending flues to boilers of the
locomotive type, in order to detain the hottest of the products of combustion,
and so to economise heat and fuel by the absorption of the heat into the
boiler.
Eighth, the general forms, arrangements, and combinations of parts, or auy
mere modifications thereof, whereby the objects above-mentioned are to be
effected as herein-before described, and according to the Drawings aunexed.
In witness whereof, 1, the said Daniel Kinnear Clark, have hereunto
set my hand and seal, this Twenty-eighth day of May, in the year
of our Lord One thousand eight hundred and fifty-eight.
D. K. CLARK. (L.S.)