IMPROVEMENTS IN THE PRO- DUCING OF MOTIVE POWER, AND IN THE MEANS AND APPARATUS EMPLOYED THEREFOR."
Year: 1877

page_text: LETTERS PATENT to Robert Little, of Greenock, in the County of Renfrew,
North Britain, Merchant, for the Invention of "IMPROVEMENTS IN THE PRO-
DUCING OF MOTIVE POWER, AND IN THE MEANS AND APPARATUS EMPLOYED
THEREFOR." A communication from abroad by Dugald Little, residing at Sydney,
New South Wales.
Sealed the 4th May 1877, and dated the 28th February 1877.
PROVISIONAL SPECIFICATION left by the said Robert Little at the Office
of the Commissioners of Patents on the 28th February 1877.
ROBERT LITTLE, of Greenock, in the County of Renfrew, North Britain, Merchant.
IMPROVEMENTS IN THE PRODUCING OF MOTIVE POWER, AND IN THE MEANS AND
APPARATUS EMPLOYED THEREFOR." A communication from abroad by Dugald
Little, residing at Sydney, New South Wales."
دو
This Invention has reference to improved means of and apparatus for producing
or generating a new or improved hot expansion pressure fluid to be used in ordinary
engines or cylinders for motive-power purposes, and which it is considered will give
out more power for the heat and fuel used than has heretofore been obtained, and
will therefore be much more economical than the hot fluids and the motors or
engines heretofore in use.
The nature and novelty of the Invention consist in the use of a mixed fluid
formed of high-pressure steam or steam above the pressure of the atmosphere, and
the hot high pressure gaseous products of combustion from a close-pressure com-
bustion furnace, the gases being led or forced from the said close fuel or gas com-
bustion furnaces into the close steam boiler or generator, preferably in jets through
the water, so as to heat and generate the steam therefrom while combining or
mixing therewith within the boiler, from which it will be conducted in the same or
usual manner that the high-pressure steam and other hot expansive or elastic pres-
sure vapours, gases, and air have been in the various well-known forms or classes
of reciprocating or rotary engines or motors for motive-power purposes.
By the improvements, of this Invention therefore the combustion furnace or
chamber, whether of the forms necessary for burning ordinary fuels, as coal, coke,
wood, charcoal, pitch, mineral or other oils or mixtures of these, or gases produced
11

page_text: from these, or mixtures of oils and steam, and led into the furnace, would be made
close and of a construction to withstand the internal pressure, and worked by forced
combustion, that is, by forcing the air (or gases) in through the grate or other
suitable orifice into the combustion chamber.
This close combustion furnace may be made within the strong flues of the boiler,
preferably below the water line, or it may be made of sheet iron or of cast iron, or
of steel plates secured together outside, and may be lined with fire-brick and clay
inside, and as usual, surrounding the whole or a part of the outside surface of
the boiler below the water space; that is, when the flames and heated products of
combustion are to be used to heat the boiler or its heating tubes before being led or
forced into it; or otherwise, the furnace may be made self-contained and separate
from the boiler, and have the flames and hot gases conducted therefrom to act on
the heating tubes or other heating surface of the steam boiler before entering it
when this is desired; but the heated products of combustion might in some cases be
directly conducted or forced (as before stated) preferably in a great number of small
jets up through the water, as from a rose pipe ranged along the bottom or lower
part of the boiler, the entrance part of this pipe being fitted with an inlet or check
valve which would allow all the hot gases from the furnace to pass the valve into
the boiler when their pressure was greater in the furnace, or its conducting or
forcing pipes outside, but would shut when the pressure was greatest in the boiler
so as to prevent water, steam, or vapour escaping through this valve.
The air necessary for supporting the combustion of the fuel or gases employed in
the furnace would under these improvements require to be forced into it by any
ordinary air or other pump, or reciprocating or rotary blower capable of producing
a greater pressure than that within the furnace to insure rapid and constant com-
bustion being kept up; and the pressure within the furnace would require to be
somewhat greater than that of the steam within the boiler when it was desired
simply to lead the hot gases direct therefrom into the boiler, but a pump or rotary
or other blower might be used for drawing and forcing the hot gases from the
furnace into the boiler.
When ordinary coal, wood, or coke is used for fuel, it might be fed in through
charging revolving feeders or hoppers with inner and outer closing valves or doors,
opened and closed at intervals as desired, on to the furnace grate or bars; and the
air would mainly be forced into the close chamber or ash-pit below the grate for
consuming the solid carbon, while sufficient air would be forced, preferably in a
heated state, above the fire for igniting the hydrocarbon or other inflammable gases
evolved from the fire so as to prevent the formation of smoke or soot as much as
possible.
When combustible gas and air only are used and forced into the combustion
chamber to make the hot high pressed gases to be forced into the steam boiler the
furnace or combustion chamber might be quite close, having only the pipes con-
trolled by valves, and leading into and from the chamber; but when coal or other
fuel is used a tight closing furnace door near the hearth or furnace bars is required
for inserting the fuel or cleaning the fire, and insuring the proper combustion of the
fuel, and also a close ash or refuse discharge chamber with one or more close fitting
dampers or valves, the furnace having a chimney for allowing the escape of the
gases when they were not being forced into the steam boiler, and vice versa, closed
when they were.
Although only mechanical pumps and blowers have been herein-before mentioned
for drawing and forcing the air to the furnace, and the hot gaseous products from it
into the steam boiler, it is to be understood that jet fluid blowers may be employed,
and that in some cases the hot expanded gases and steam, after having done their
work in the engine, might be led into jet surface or other condensers where water is
plentiful, which would give a considerable vacuum in the cylinder to be utilized in
working effect, or otherwise the exhaust hot vapours or gases might be used for
heating the feed water for the boiler.
A pressure receiver or accumulator may be used for the air, or the gaseous pro-

page_text: ducts of combustion being forced into before their admission into the furnace or
the steam boiler, and these might be made to pass through wire gauze or a dip
pipe water tap, or other equivalent, to prevent sparks or fine dust from passing
in with them into the said receiver or into the boiler.
The locomotive form of boiler and furnace, with strong furnace closed in below,
and pressure-tight doors and dampers, with great heating surface and steam-
generating power of boiler would be a good construction of combined steam
generator and furnace for this new or improved combined furnace gases and
steam motive fluid and engine or motor, especially for marine and land pro-
pulsion purposes. And to prevent the too frequent necessity of opening the furnace
charging or cleaning doors the cheap residues of or crude oils left in the distillation
of mineral and other oils and kerosene may be used as a fuel, either along with coal
or other ordinary fuels, or by itself, and forced into the furnace in jets or as a
spray by gravitation or pumping, or by jet injectors, along with and by the lateral
action of jets of air or steam preferably superheated.
In some cases, as for stationary engines where there is plenty of room, an extra
furnace or furnace and boiler may be used, all these being fitted with separating'
pressure-tight doors or dampers, each of which could be shut off in turn while the
furnace was being charged or cleaned, and opened up again immediately.
The gases would preferably be admitted to the boiler at various points, as at both
ends, and at one or more intermediate parts in the middle, and when led direct
without forcing apparatus the pressure in the furnace would always require to be
greater than that in the boiler, and both would be fitted with pyrometers in-
addition to pressure gauges as well as the usual mountings on the steam boiler as
water gauges and float and safety valves.
The new or improved combined motive fluid (of gas and steam) so produced, in
accordance with this Invention, may be used and cut off to act expansively in single
or double cylinder or compound engines as steam and other expansive fluids have
been.
SPECIFICATION in pursuance of the conditions of the Letters Patent and
of an Order of the Lord Chancellor filed by the said Robert Little in the Great
Seal Patent Office on the 11th September 1877.
ROBERT LITTLE, of Greenock, in the County of Renfrew, North Britain, Merchant.
"IMPROVEMENTS IN THE PRODUCING OF MOTIVE POWER, AND IN THE MEANS AND
APPARATUS EMPLOYED THEREFOR." A communication from abroad by Dugald
Little, residing at Sydney, New South Wales."
The nature, novelty, and mode of performing or carrying out this said Invention
into effect or practice consist in the use of new or improved modes and means of, or
apparatus for, producing or generating a mixed hot expansive pressure fluid to be
used in ordinary engines or, cylinders for motive-power purposes, composed or
formed of high-pressure steam, or steam above the pressure of the atmosphere, and
of hot air and the gaseous products of combustion at a high pressure and temper-
ature produced from coal or other solid carbon fuel, or crude oils left in the
distillation of mineral and other oils and "kerosene," or a mixture of these within
pressure combustion furnaces, the said hot air and gases being led or forced from the
said close fuel and air and gas combustion furnaces into the close steam boiler or
generator, preferably in jets through the water, fed into it as usual, so as to heat and
generate the steam therefrom while combining or mixing therewith within the
boiler, from which this mixed motive fluid will be conducted in the same or usual
manner, that the high-pressure steam and other hot expansive or elastic pressure
vapours, gases, and air, have been in the various well-known forms or classes of
reciprocating or rotary engines or motors for motive-power purposes, which mixed
motive fluid it is considered will give out much more power for the fuel used than

page_text: has been obtained from the hot expansive fluids and their motors or engines hereto-
fore in use, and consequently be much more economical.
By the improvements of this Invention therefore the combustion furnace or
chambers, whether of the forms necessary for burning ordinary fuel as coal, coke,
charcoal, pitch, mineral or other oils, or mixture of these, or gases produced from
these, or mixture of oil and steam and led into the furnaces, would be made close
and of a construction to withstand the internal pressure, and worked by forced
combustion, that is, by forcing the air (or gases) in through the grate or other
suitable orifice into the combustion chambers.
This close combustion furnace may be made within the strong flues of the boiler,
preferably below the water line, or it may be made of sheet iron or of cast iron, or
of steel or copper plates, or of other suitable material secured together outside, and
may be lined with fire-brick and clay inside, and as usual surrounding the whole or
a part of the outside surface of the boiler below the water space, that is when the
flames or heated products of combustion are to be used to heat the boiler or its
heating tubes before being led or forced into it; or otherwise, the furnace may be
made self-contained and separate from the boiler, and have the flames and hot gases
conducted therefrom to act on the heating tubes or other heating surface of the
steam boiler before entering it, when this is desired, but the heated products of
combustion might in some cases be directly conducted or forced (as before stated)
preferably in a great number of small jets up through the water as from a rose pipe
ranged alongside the bottom or lower part of the boiler; the entrance or other con-
venient and suitable part of this pipe being fitted with an inlet or check valve,
which would allow all the hot air and gases from the furnace to pass the valve into
the boiler when their pressure was greater in the furnace or in its conducting or
forcing pipes outside, but would shut when the pressure was greatest in the boiler,
so as to prevent water, steam, or vapour escaping through this valve back into the
furnace, or other suitable apparatus might be connected with the pipe to effect the
same purpose.
The air necessary for supporting the combustion of the fuel or gases employed in
the furnace would, under these improvements, require to be forced into it by any
ordinary air or other pump, or reciprocating or rotary blower capable of producing
a greater pressure than that within the furnace to ensure rapid and constant
combustion being kept up, and the pressure within the furnace would require
to be somewhat greater than that of the steam within the boiler, when it was
desired simply to lead the hot air and gases direct therefrom into the boiler, but a
pump or rotary or other blower may be used for drawing or forcing the hot air and
gases from the furnace into the boiler.
When ordinary coal, wood, or coke is used for. fuel it might be fed in through
charging revolving feeders or hoppers with inner and outer closing valves or doors
opened and closed at intervals as desired on to the furnace grate or bars, and the air
would be forced into the close chamber or ash-pit below the grate for consuming
the solid carbon, while sufficient air would be forced either in a heated state or not,
as found desirable, above the fire for igniting the hydrocarbon or other inflammable
gases evolved from the fuel or fire, so as to prevent formation of smoke or soot as
much as possible.
When coal or other solid fuel is used, a tight closing furnace door near the hearth
or furnace grate or bars would be required for supplying the fuel or for tending and
cleaning the fire to insure the proper combustion thereof, and also a close ash or
refuse discharge chamber, with one or more close fitting dampers or valves, the
furnace having a chimney for allowing the escape of the gases when they were not
being led or forced into the steam boiler, and vice versa, closed when they were ;
but such charging and cleaning doors might not be required when oils or liquid
fuel were used to make the combustible gases with the air to be forced into the steam
boiler, in which case the furnace or combustion chamber might be close, having
only the pipes controlled by valves or taps leading the air and liquid fuel into
the combustion chamber, which might have man-hole doors or apertures to be

page_text: opened occasionally, or having mica windows therein, for inspecting the state of
combustion.
Although only mechanical pumps and blowers have been herein-before mentioned
for drawing and forcing the air to the furnace, and the hot gaseous products from it
into the steam boiler, it is to be understood that jet fluid blowers may be employed,
and that in some cases the hot expanded air and gases and steam, after having done
their work in the engine, might be led into jet surface or other condensers where
water is plentiful, which would give a considerable vacuum in the cylinders to be
utilized in working effect; or otherwise the exhaust hot vapours or gases might
be used for heating the feed water for the boiler fed into it by the injectors or feed
pumps as usual.
A pressure receiver or accumulator may be used for the air being forced into,
before its admission into the furnace, between the air pumps and the furnace.
The locomotive or horizontal tubular form of boiler and furnace, with strong
furnace closed in below, and pressure-tight doors and dampers with great heating
surface and steam generating power of boiler, would be a good construction of
combined steam generator and furnace for this new or improved combined furnace,
hot air, gases, and steam motive fluid, and engine or motor, especially for marine
and land propulsion purposes. When crude mineral oils or " kerosene are used as
fuel in these close high-pressure furnaces, they would be forced into the furnace in
jets through small pipes or nozzles, or as a spray by gravitation or pumping, or by
jet injectors along with and by the lateral action of jets of air or of steam, preferably
superheated.
33
In some cases, as for stationary, marine, or other engines, where there is room, an
extra furnace or furnaces and boiler may be used, fitted with separating pressure-
tight doors or dampers, each of which could be shut off in turn while its furnace
was being charged or cleaned, and opened up again when this was done.
The gases would preferably be admitted to the boiler at various points, as at both
ends, and at one or more intermediate parts in the middle or along the whole length of
the boiler, and when led direct without forcing apparatus the pressure in the furnace
would always require to be greater than that in the boiler, and both would be fitted
with pyrometers in addition to pressure gauges, as well as the usual mountings on
the steam boiler, as water gauges and float and safety valves, and man-hole and
sludge doors; this said mixed combined motive fluid of hot air, gas, and steam so
produced in accordance with the Invention may be used and cut off to act
expansively in single or double cylinders or compound engines, or rotary or other
motive-power engines, as steam and other expansive fluids have been heretofore.
In order that the mode and means of performing or putting the Invention into
effect or practice may be properly understood, I shall now proceed to describe the
Sheet of Drawings which I have hereunto appended for that purpose, the same
reference letters indicating the same or corresponding parts where these are seen in
the several Figures.
Figures 1 and 2 are respectively a longitudinal section and half end elevation and
section through the fire-box of a furnace and steam boiler, or new or improved
generator for producing the combined motive-power fluid of hot air and gases from
coal or other solid carbon fuel, or this combined with crude mineral oils or kerosene,
or their waste residues in and from the furnace mixed with the steam of the water
or steam boiler, all constructed in accordance with and illustrative of one mode and
means or arrangement of apparatus for performing this Invention; and Figures 3
and 4 are cross sections of the steam boiler at the parts or lines 3 - 3, and 4 4,
in Figure 1, to show some of the details connected therewith more clearly.
Referring to Figures 1 to 4, A is the fuel furnace shown in this arrangement as
nearly rectangular, made of cast-iron plates a, strongly bolted together outside, and
to one end of the water or steam boiler B of the horizontal tubular type or form, all
fluid pressure tight capable of resisting the internal pressure required. The
furnace A is formed preferably with an arched top or crown A¹ above, and hollow
segmental fire-grate of furnace bars A", with close ash-pit A¹¹ below, all lined with

page_text: fire-brick inside, and at the end and in front of the tube plate 6 of the boiler B; but
it might be made in a cased form with circulating water space all round and directly
connected above and below to the boiler B, as in locomotive engine boilers. The
fuel at Z when dross or small coal is used, is fed in as shown through two close
feeding cases or chambers C, one at each side and front of the furnace, with internal
revolving vane cylinders C₁, or it might be vane screws turned at a slow speed by
the screw shaft C in front, working into serew pinions C2 on the ends of the
feeding cylinder shafts C111, all so as to feed the coals or fuel slowly in from the deep
hopper C connected to the case C, and closed in by a lid C on top, and filled at
intervals as the supply gets exhausted; the coals thus being fed in by the revolution
and force of the vanes C (or screw) on to the front upper side parts of the grate-
bars A, so as to gravitate down and spread over the curved bars, assisted at times
by spreaders or bars worked through closing holes d, provided for that purpose in
the front end or sides of the furnace doors D, preferably fitted with screws D¹, as
retort doors for making them pressure fluid tight, and yet easy of removal for
inspection and cleaning of the furnace at intervals; and these doors might be fitted
with mica windows d¹ for seeing from the outside the state of combustion of the
fuel and gases within, and for regulating the supply of air thereto accordingly.
The air in this close furnace is forced in through the pipes or nozzles E from
ordinary air forcing pumps or other blowers into the furnace A and ash-pit A
above and below the grate, to burn the solid carbon of the fuel on the grate and
the gases evolved in the fire-box A above, either from the said fuel or from the
liquid oil fuels herein-before referred to, and shown as supplied through the nozzles.
and pipes f, f¹, from any adjacent tanks or vessels, by pumps or other equivalent,
so as preferably to inject or deliver the oil fuel in small streams, jets, or spray over
the top of the hollow hearth G, which would receive all that was not instantly
raised into gas by the heat and flames passing up each side of it from the coal fire
on the grate A" below, which, with the flames passing up in front of and over the
bridge hearth G, would burn off all the hydrocarbon gas in the oil or tar deposited
on it, while the carbonized residues could be knocked off this hearth G down into
the fire below (to be burned with the coal) from time to time as they accumulate
by bars through the holes d in the doors D for that purpose, and for inspecting and
cleaning the fire when required. Cleaners or bars f" are also fitted in the liquid
nozzles to clean them inside and outside, and also when desired to knock away
all carbonized residues which may accumulate and obstruct the free admission of
the oil to be forced in by the pumps through the pipes f¹.
At the back end of the furnace A a close recess A4 is formed for receiving the
waste ash or clinkers pushed back through or over an opening a' in the back bridge
or wall a, while the fire is going, and formed with side doors A5 for being
cleaned out when full, or at intervals when convenient.
As arranged in this application or construction of horizontal tubular boiler B, all
the hot air and gases from the fuel and furnace A pass directly through the two sets
or rows of tubes H into the back flue chamber H¹ (or smoke box), and heat or boil
the water within the boiler B by the radiation of the heat through the tubes H in
its passage. The gases pass from the chamber H¹ through the valve chest I¹¹ into
the whole of the rose pipes or tubes h through holes h¹ in the upper side of which
the gases pass in small streams into the water, so as to boil the water and mix with
the steam raised in the upper space b above the water, thus forming the before-
mentioned mixed expansive pressure motive-power fluid of hot air and gases from
coal or other solid carbon fuel and oils from the furnace with the steam within the
boiler, all in accordance with the improvements of this Invention, ready for being
led by conducting pipes and controlling valves as usual to the cylinders of any
ordinary construction of engine for motive-power purposes. The back flue H¹ is fitted
with outlet pressure fluid-tight slide valve or damper z, leading to the chimney 2¹, to
be opened to cause a draught in the furnace A while kindling and getting up or
cleaning the fire, and closed when set properly to work under forced combustion,
with a pressure in the furnace A greater than within the water boiler B ; and to

page_text: insure which, as well as the proper distribution of the hot air and gases through the
water in the boiler B, the valve I is fitted at the entrance to the rose or perforated
tubes h, preferably of the gridiron or brander construction, to give great area with
a short shift for closing and opening it, effected by its rod I working out through
stuffing boxes I2, and actuated by a small pressure cylinder and piston, the inlet
exhaust valve of which is controlled and actuated by the motion of a small piston
and cylinder having its opposite ends open, the one into the boiler B and the other
into the box H, open to the furnace A, all so that when the pressure becomes
greatest in the boiler it causes the valve I to shut, and, vice versa, to open when
the pressure is greatest in the furnace A and flues H, H', but other arrangements
of valves or equivalents might be used to thus close the communication between the
water in the boiler and the furnace flues to prevent the water being forced out of the
boiler into the flues and furnace.
The fire may be kindled and set on by the door D on the grate A" (with the
damper open, and the valve I shut to give draught to the fire), and as soon as the
fire is good within the furnace A the doors D and dampers are firmly closed, and
the pressure got up by forced combustion, blowing or forcing in the air by the pipes E,
regulated by taps or valves to ignite or burn all inflammable gas and carbon of the
fuel in the furnace A with the production of as little smoke as possible, when the
valve I is opened by hand, and the hot air and gases passed in through tho
perforated pipes /, h³, and water within the boiler B, all as indicated by the arrows
and darts in Figure 1, in accordance with this Invention.
It will be understood that other forms or arrangements of furnaces A. for the
burning of coals or other mineral fuel by itself, or combined with the said crude
mineral oils, kerosene, or their residues in refining and distillation, and of the shape
or construction of the boiler B, and arrangement of the pipes H, h, h¹, and valve I,
or their equivalents for conducting the hot air and gases from the furnace, and
passing the same through the water to produce and mix with the steam therein.
Although not shown in the Drawings it will be understood that the mixed elastic
pressure fluid produced in this new furnace and boiler might be conveyed into or
through any ordinary arrangement of superheater, after leaving the boiler B before
entering or being used in the motive cylinders or engines, as steam is sometimes
done; or that a portion of superheated air or steam might be so added to it in its
course to the engine to make the motive fluid more dry and elastic than it would
be if taken direct from the water boiler B. Pyrometers would be fitted on the said
superheater and in the furnace A and boiler, or their conduits, as also all the ordinary
safety water and pressure gauges and valves, drawing off tap, and cleaning door
usual to motive steam boilers and their flues.
Instead of having one automatically acting valve I controlling the inlet of the
gases to all the distributing rose or perforated tubes h, h¹, these tubes from the
furnace or its flues, as shown in the large sections and plan of these, shown in three
different arrangements in Figures 5, 6, and 7, might have the holes ¹ on their
upper side closed by self-acting covers or long valve lids j, j¹, j, a little heavier
than the specific gravity of the, water, so that they would easily lift when the
pressure of the hot air and gases in the furnace A was greater than in the boiler B,
and vice versa, close when the pressure was greater in the boiler;
these covers as
shown at j in Figure 5 are made in the form of a long horizontal rod covering one
row of holes h¹ in the upper side of each tube h, which is cupped or grooved to fit
the rod, fitted with the bow gaurds / above at intervals to guide and prevent the
rod from rising too high, and those shown at j", ", in Figures 6 and 7, are preferably
made in a convex and concave segmental form respectively to cover one or more
rows of holes h¹ in the upper part of the tubes, and preferably in short lengths
guided on studs at their ends, which also prevent them from rising too high, so
that they may open and close quickly on the change of pressure.
Having now described the nature of the said said Invention and the manner of
performing the same, I have to state that I do not confine myself to the precise
details herein described or delineated, but what I consider novel and original and

page_text: therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, the new or improved mode and means or general construction
of furnace and boiler and fittings, for producing a mixed elastic pressure fluid of
hot air and gases and steam for motive-power purposes, all substantially in the
new or improved manner herein described, or any mere modification thereof.
In witness whereof, I, the said Robert Little, have hereunto set my hand and
seal, this Twenty-fifth day of August, in the year of our Lord One thousand
eight hundred and seventy-seven.
ROBERT LITTLE. (L.S.)