New or Improved Method of and Apparatus for Burning Coal and Hydrocarbon Fuel.
Year: 1890

page_text: Date of Application, 21st Oct., 1890-Accepted, 3rd Jan., 1891
New or Improved Method of and Apparatus for Burning Coal and
Hydrocarbon Fuel.
A communication from abroad by ALLAN MASON, of Brooklyn, King's County,
State of New York, United States of America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, & 323 High Holborn, in the County of Middlesex, 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 :-
This invention relates to a method of and apparatus for burning coal and bydro-
carbon fuel in combination.
The improved method of burning pulverized coal and liquid bydrocarbon fuel
together consists in injecting the pulverized coal into and about the flame of an
injected oil fire, and keeping the coal in suspension so that the combustion of the coal
is largely facilitated by the oil fire, and in such manner that the coal is consumed
without coming in contact with the oil that sustains the oil fire, which it is desirable
to avoid, because, when oil is projected on or comes in contact with the coal in the
combustion chamber, it seems to extract suddenly from the coal the more volatile
portions, which consume readily and leave the rest of the coal hard and slaty, so that
it does not burn readily, and becomes a compact mass that chokes up.
The coal in a finely comminuted state, and air, are injected together into the
furnace chamber above a still air space below for reception of the ashes, and, by
suitable appliances, are caused to deflect upward over and backward above the
incoming jet, so that for a time the coal is maintained in suspension by the forces of
the said incoming jet for the more rapid and effectual combustion, and so that the
larger particles not yet consumed and falling into the incoming jet will be continued
in suspension by being again taken along by said jet. And at the same time, the
liquid hydrocarbon fuel is also injected by compressed air or steam, so as to receive
the coal atoms in the oil flame, but not in such juxtaposition as that the oil will mix
with the coal prior to the combustion of the oil, all as hereinafter fully described,
reference being made to the accompanying drawing, Figure 1, which represents a
longitudinal sectional elevation of a boiler furnace with apparatus contrived for
carrying out the invention.
In this device, a represents the furnace chamber, 6 the ash pit in the lower part of
said chamber, the flue space back of the combustion chamber, g the bridge wall,
d the fire door, f' the ash pit door, g' the partition for directing the products of
combustion backward through the lower fines of the boiler, h' the hood at the front
end of boiler for deflecting the same forward again through the upper flues of
In such
the boiler, and the chimney through which the smoke escapes into the air.
or any other approved or suitable furnace, the fan blower j¹, nozzle k, and a feed
hopper are provided for injecting and maintaining the fine coal in suspension, said
hopper being connected with and discharging a regulated continuous stream of fine
coal into the discharging pipe m, of the fan, so that said stream will be injected into
the furnace through nozzle k, along with the blast of air from the fan, and be
projected upward, and backward along and above the incoming jet, as by the pan
deflector h, on which the incoming jet first impinges and is turned upward to
deflector i, in the upper part of the chamber, which projects it backward over the
incoming jet, the deflector, j, projecting the unconsumed particles downward again
into the same, thus maintaining the coal in continuous cycles until it is wholly
consumed while in suspension. Together with the coal thus injected and held in

page_text: suspension, oil is also injected and the flame thus produced is combined with the coal,
which, being thus maintained in suspension, produces a more intense flame which is
also augmented by means of the gases resulting from the decomposition of steam
employed to inject the oil, a more complete combustion of the coal is hereby ensured
which coal, if burned alone, is not as effective owing to considerable waste
through the precipitation of considerable percentage of unconsumed particles into
the ash pit. For this purpose, a steam nozzle w, is employed, arranged in an air
induction tube y, with an oil feeding pipe a, introduced at the fire door and dis-
charging, into the coal jet from the side of the furnace opposite to that from which
the coal jet comes, for more effectual commingling of the oil flame and coal jets and
the better maintenance of the cycles for bearing up the coal. The oil pipo is
arranged to drop the oil on to the steam nozzle near the end of the latter for the
mixing of the air and oil around said nozzle and drawing them together off the end
of the nozzle into the steam, said pipe being connected with a reservoir. The steam
nozzle may have suitable connection with the boiler for the supply of the steam.
. In practice, the coal will be used in much larger proportion than the oil for the
most economical results, but the invention is not limited to any proportions.
The ashes will settle down in the eddies at the sides of the coal injector to the ash
pit or in the space behind the bridge wall.
The oil flame is so projected in opposition to the coal jet that the coal atoms are
turned away so that they do not enter the oil fire far enough to reach the oil spray
before the oil is ignited, and thus the coal is burned without coming in contact with
the liquid oil.
Referring now to Figures 2, 3 and 4.
The modified apparatus for burning coal and hydrocarbon fuel in combination
consists of contrivances for burning the oil or oil vapors or gas in one or more
suitable burners therefor, located in the furnace chamber somewhat higher than the
ash pit, with ample surrounding space for the ashes to descend into the pit without
clogging these burners, and at the same time maintaining a fire of coal around and
above the oil or vapor burner or burners with pulverized coal atoms in suspension and
general distribution throughout the chamber, together with the requisite amount of
air for the support of combustion so that the mixture and union of atoms are in
process of operation among and throughout the moving particles in all the space and
in far greater amount and intensity than when burned in a mass or bed on the coal
grate, with correspondingly more effective or perfect combustion and greater
production and intensity of heat in a given space.
Apparatus is used by which air jets or blasts may be introduced in such manner
as to produce currents, counter-currents, eddies and cycles calculated to bear up and
distribute the coal till consumed, the coal being preferably introduced along with and
by said jets, but it may be otherwise introduced if desired. Sectional burners are
used for supplying the oil or other hydrocarbon or gas fuel, that is, burners located
in different sections or localities of the lower portion of the furnace chamber, with
ample space between and below them for the precipitation of the ashes below thei
from the coal fire, all as hereinafter fully described, reference being made to
Figures 2, 3 and 4 of the accompanying drawings.
Figure 2 is a longitudinal sectional elevation of an ordinary boiler furnace with
apparatus for injecting coal particles and maintaining them in suspension together
with apparatus for maintaining a sectional fire of hydrocarbon fuel in the lower
portion of the combustion chamber.
Figure 3 a transverse sectional elevation of a locomotive boiler furnace with similar
apparatus.
Figure 4 a horizontal section of Figure 3.
In Figure 2, a represents an ordinary return flue boiler, 6 the combustion chamber
of the furnace, d the fire door, e the ash pit and f the flue behind the bridge wall.
In such furnace, deflectors h, i, j, are provided of refractory material as shown in
any approved arrangement with an injector k, for air, to be forced in preferably at the
back of the chamber by a fan l, or other means, and coal dust charged into the air

page_text: spout by a screw feeder m, or other means to be carried along for feeding the furnace
and for being mixed and combined with the air and held in suspension for combustion
by it.
It will be seen that the blast first traverses the chamber a little above the ash
pit, spreading more or less, then it is turned upward violently by the deflector 6,
and, coming in contact with deflector i, is thrown forward against j, which turns it
downward into the incoming blast which takes along with it any yet unconsumed
particles and prevents them from falling into the ash pit. It will also be seen that
these appliances may be readily fitted to a common boiler furnace already in use
without material expense of fitting and may be as readily removed.
For adaptation of the same method of consuming coal atoms in suspension in
the combustion chamber, b, of a locomotive boiler fire box n, the injecting nozzle
may have numerous branches k', entering near each side from below the side walls
of the fire box, which, projecting upward, cut the opposite angles so as to meet
over the centre of the chamber and produce gyrating cycles by their counter action
adapted to maintain the suspension of the coal atoms until consumed.
By this method, all the combustible matters in the coal will be effectually consumed
with greater economy of fuel, and an especial advantage is gained in the total
prevention of clinker and slag. What ash is developed may in part fall into the
ash pit, through some localities where the eddies favor it, whilst some may be
carried over the bridge wall and descend where the cycles have less suspending
effect.
Together with the fire of coal atoms thus maintained throughout the chamber
generally, there is combined also an auxiliary fire of hydrocarbon or gas fuel in
various ways, such as ordinary oil burners in the lower portion of the furnace at
or about the locality of the ordinary fire bed.
As an ordinary fire of uniform spread over the area of the chamber would fail
of this purpose because it would soon be clogged with ashes from the fire above,
sectional or separate burners, p, are employed with wide spaces between them through
which the falling ashes from the upper fire may descend into the pit; said burners
being of such limited transverse extent that the ascending currents from them will
turn away into the pit such matters as might fall into them and thus be self
protecting so far as the falling matters of the upper fire are concerned.
These burners may consist of trough shaped drawers p, adapted to slide in and out
of the furnace through one side for withdrawing them from time to time for cleaning
and repairs; (but it is not essential to have them draw out) to which troughs oil may
supplied by suitable feed pipes s, from any suitable source of supply.
The troughs will be perforated in the upper portions of the sides for the supply of
, and the upper edges will preferably be flanged over horizontally as at t, which
flanges will be perforated with numerous small holes through which air will be dis-
tributed in jets from below for the better admixture with the gases and vapors rising
from the burners. The troughs will also be covered with wire gauze u, and will be
charged with refractory or refractory and absorbent material as porous stone w, or
asbestos, or hoth, some portions of which, particularly the latter, may extend up
through holes in the wire gauze for wicks to take up the oil and vapors, as at x x¹.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. The method of burning pulverized coal and oil together so that the coal and oil
particles will not come in contact with each other in the combustion chamber and
thereby preventing the collection of unconsumed slaty and obstructive deposits in the
lower part of the chamber, which consists of injecting the coal into the furnace
chamber and for a time maintaining it in suspension by the injecting forces, and at
the same time injecting oil and producing a flame thereof in and about the field of the
suspended coal so projected with relation to the coal that the flame only combines
"

page_text: with the coal and the coal is consumed without coming in contact with the oil that
produces and sustains the oil fire, substantially as described.
2. The combination, with a furnace chamber, of an air and pulverized coal injector
and a series of hydrocarbon burners separately arranged in the lower portion of the
chamber, but above a lower space for. the reception of ashes and with intervals of
space between them through which the ashes are precipitated into the space below,
substantially as described.
3. The combination, with a furnace chamber, of an air and pulverized coal injector
and a series of oil burners separately arranged with intervals of space between them
and a space below for the reception of the ashes, said burners consisting of trough
shaped drawers or recepticles and being covered with reticulated material having one
or more burner wick openings, substantially as described.
Doted this 20th day of October 1800
WM. P. THOMPSON & Co.,
Agents for the Applicant.