Improvements in or relating to Obtaining More Perfect Combustion in Furnaces and Flues, and in Apparatus therefor.
Year: 1895

page_text: Date of Application, 14th May, 1895
Complete Specification Left, 11th Feb 1896-Accepted, 14th Mar
1896
T
Improvements in or relating to Obtaining More Perfect Combustion
in Furnaces and Flues, and in Apparatus therefor.
A communication by FRANK LESLIE BARTLETT, of Canon City, in the County
of Fiemont and State of Colorado, United States of America, Chemist
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 Lancastor, 118 New Street, Birmingham, in the
County of Warwick and 31 High Holborn in the County of Middlesex, Civil
Engineor, do hereby declare the nature of this invention to be as follows
This invention has for its object the complete combustion of the cheaper grados
of fuel such as bituminous coal, culm, sawdust and like material, converting the
same into gas and coke and burning it with an air blast, thus consuming the
volatile products of the fuel and preventing the formation of smoke. The inven-
tion is also designed to be applied to the treatment of certain classes of ore which
require to be volatilised.
The invention consists of a furnace so arranged that the coal or other fuel is
first coked by the heat of the furnace, and the gases are burned in a sheet of
hydrocarbon flame over the grates in combination with a carbon flame produced
by the burning of the coked material on the gistes. The two kinds of flame are
thus mingled and burned together forming an intense heat capable of effecting the
complete combustion of the hydrocarbon fuel without smoke.
In caying out the invention a furnace is constructed having at each side of
the fire box and extending the entire length thereof, a coal receiving hopper or
pocket, the bottom of which connects with the firebox by a shallow opening
through which the coal is discharged onto the inwardly aloping grate
The floor
or bottom of the hopper is proferably formed with an inward inclination coincident
with the pitch of the grate. Along the top of the shallow opening which leads
from the hopper there is a perforated an blast pipe connected with a blower or
other source of supply.
The air blast pipe may form the top of the opening but it is preferred to
place it immediately outside of the opening and within the fire box so that it will
escape damage from the passage of coal though the opening. The air blast pipe
16 provided with a series of perforations in two rows, one immediately underneath
and pointing directly downward and the other pointing inward and downward
preferably about parallel with the sloping grate. Over the fire box and extending
from one sule of the finace to the other is a firebrick arch by which the heat is
egenerated and the combustion assisted. The usual doors are provided in front
of the furnace including an opening to give access to the space below the blast
pipes. The air blast is introduced under the gates as well as through the air blast
pipes
In operating the furnace, the coal in the lower portion of the hopper and at the
opening becomea heated and coked by the heat from the furnace. The bydrocarbon
gases are driven oft and pass into the furnace through and over the incandescent
coke which is burning on the grates and at the opening, where they meet the air

page_text: jets from the air blast pipe and are driven downward and inward to the centic from
each side, meeting the air which comes up through the grate. The result is a
combined hydrocarbon and carbon flame coming from each side and forming a vortex
in the centre where complete and smokeless combustion takes place
At the point where the gases ignite, namely, at or near the blast pipe, they get
air from three different points, the two rows of holes and from under the grates,
and the heat is kept up at that point by the incandescent coke as well as by the
high degree of heat maintained throughout the entire furnace. For this reason no
smoke is formed and a perfect combustion is effected, resulting in an intense heat
The more smoky the coal or the more hydrocarbon contained in it, the hotter the
fire and the greater the efficiency of the furnace. When non-coking bituminous
or lignite coal is used, it will feed itself through the opening as it buins out on the
grate but when coking coals are used the coke forms into lumps and it is necessary
to occasionally insert a bar at the outlet of the hopper and work the coke down
If desired an automatic feeding device may be used.
The coal may be introduced into the hopper from the front of the furnace or it
may be fed from on top
The furnace may be placed directly underneath the forward end of the boiler o
It may be detached therefrom and the burning gases led to a point beneath the
boiler through an exhaust flue.
For puddling furnaces, health or reverberatory furnaces, the heater can be placed
in direct connection and when used as a forge the nou may be heated duectly on
the hearth of the furnace
For 1oasting ores, making pigments, or volatilizing lead, zinc or other volatile
metals, the crushed ore may be mixed with the coal and changed to the pockets
or it may be thrown through the door onto the hearth but the former method is
considered the preferable one.
Dated thus 19th das of Nov 1805
Improvements in or relating to Obtaining More Perfect Combustion
in Furnaces and Flues, and in Apparatus therefor.
A communication by FRANK LESLIE BARTLETT, of Canon City, in the County
of Fremont and State of Colorado, United States of America, Chemist.
1, 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, 118 New Street, Birmingham in
the County of Warwick and 31 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 has for its object the complete combustion of the cheaper grade-
of fuel such as bituminous coal, culm, saw-dust and like material, converting the
same into gas aud coke and burning it with an air blast, thus consuming the
volatile product of the fuel and preventing the formation of smoke. The invention
is also designed to be applied to the treatment of certain classes of ores which
require to be volatilised.
'
The invention cousists of a furnace so arranged that the coal or other fuel 18
first coked by the heat of the furnace, and the gases are burned in a sheet of
hydrocarbon Hame over the giates in combination with a carbon Jame produced

page_text: the complete combustion of the hydrocarbon fuel without smoke.
In the accompanying drawing a furnace is illustrated which is well suited to
carry out the mvention, in which,
Fig 1. represents a cross section on the line of Fig. 2
Fig. 2 18 a central longitudinal section on the line y y of Fig. 1, and
Fig. 3 is a fi ont elevation
A, represents the furnace proper, the same consisting of the end walls m n and
the side walls aa with the arch oi dome h
On each side of the furnace and outside the walls a a is a buttiess band between
the upper part of the buttress ant the wall a is formed a pocket e for the reception
of the coal or other fuel. The lower portion of the pocket has a narrow or
contracted outlet beneath the walls a and connecting with the furnace proper
immediately above the gates G
At the lower outlet of the pocket there is an air blast pipe to furnish an for the
combustion of the gases As here shown this an pipe is placed over the opening
o that the fuel as it descends will pass directly under it, and this pipe is made use
of to support the side walls a a The pipe D D is perforated with numerous holes
and it is preferred to anange them with one row of holes directly underneath,
so that they will blow vertically downward, and with another low pointing
obhquely downward on the inside of the furnace The grate Gis finely perforated
and that portion which lies next the opening 7 of the pockets is sloped or
inclined ward, as it is preferred to construct it, so that when the coal or coke
falls on it from the pocket, it will slide downward toward the centic of the giate.
The central portion of the giato 18 made horizontal, also that the cinders aud
ashes as they collect here may be readily removed by means of the door g¹. The
door communicates with the ash pit
Means are provided for supplying air under pressure to the blast pipe D and
to the ash pit beneath the giate.
Air is taken from the au duct F which extends at right angles to the furnace
and the pipe D connects with the upper part of this air duct. The short pipe ƒ
A hot
connects it with the ash pit. The pipe 15 controlled by the damper r
blast 15 provided for under the grate by connecting the forward end of the air
pipe D with a pipe which returns into the ash pit
An exhaust fine E is constructed as herem shown over the air duct F the lutter
being provided with a dome y, and the products of combustion from the furnace
pass into the flue through the opening
The operation of the furnace is as follows, viz :
A fire is first started on the grate G and the coal is charged into the pockets cc.
Blast is turned on in the flue F, and when the furnace is sufficiently heated the
coal in the bottom of the pockets becomes hot enough to throw off hydrocarbon
gaseя
These gases are prevented by the coal in the pockets from passing upwards and
they are consequently driven downward under the air blast pipes D D and into the
furnace, mingling with the jets of air which come from the pipes and burning in a
sheet of hydrocarbon flame. The coal as it works downward parts with its gases
and becomes cohed so that when it reaches the giate it is reduced to the condition
of pure carbon oi coke The hydrocarbon flame of the expelled gases and the
carbon flame of the coke buning as they do together and in contact with each
other produce an intensely hot flame which 13 absolutely smokeless for the reason
that the smoke has no opportunity to form. The two flames, being blown from
opposite sides toward the centre, meet and form a mass of flame which passes out
of the furnace and is made use of for heating boilers or for metallurgical operations
or any other manner desired.
The effect of these side blasts blowing toward each other is first to prevent the
fine stuff from blowing over into the flues whero it would ordinarily be carried by

page_text: the up blast through the gates, and second the horizontal side blasts impinge the
flame down onto the flame coming up through the grate
As the coal is consumed fresh coked coal slides down onto the grates and is
burned by the air blast which comes through the perforated gate, thus making the
feed automatic and continuous. The sloping grate is inclined just enough so that
only a thin layer of coal can at one time be forined
The pipes DD become very highly heated so that the air blast which issues
from them is very hot and the surplus heated an pisses on through the grates,
this heating the blast there, so that a hot blast is delivered from all points.
In burning coal for heating purposes only, as for steam boilers, forges, rever-
bentory furnaces &c. De attendance is required except occasionally to ban up any
cliuke which forms on the grate and diлw it out of the door g'.
No smoke is produced because the coal is fist coked and the gases burned in
combination with the coked coal, the an blast in connection with that introduced
through the au blast pipes rendering the formation or escape of smoke impossible.
The combustion of the coal is very complete and very little clinker of ash is left
ou the gate. The heat can also he maintained at a perfectly even temperature at
all times since the coal feed is continuous and uniform
In using the furnace for the purpose of heating steam boilers a flue is un direct
from the dome of the furnace to a point under the boilers and the furnace can be
placed if dosed some distance from the boilers to be heated, since the gas flame
produced extends a long distance into the exhaust fluc.
For puddling furnaces, hearth or reverberatory fnaces, the heater can be placed
if desired in duect connection, and when used as a forge the iron may be heated
directly on the hearth of the fui naco.
For roasting ones, making pigment of volatilising lead, zinc or other volatile
metals, the crushed ore may be mixed with the coal and charged into the pockets
or it may be thrown though the door onto the hearth, but my correspondeut
considers the former method the preferable one. After burning, the clunker or
Peoria which is formed in the operation may be removed through the door of the
furnace.
The furnace herein described is well adapted to the manufacture of zinc oxide
or zinc-lead pigment as no smoke is produced to contaminate the product.
While I have, on behalf of my correspondent, particularly set forth the con-
struction of a furnace which 18 woll fitted to carry out the invention, it is obvious
that many modifications may be made while yet keeping the limits of the invention
as set forth in the claims and he therefore desires it understood that he does
not wish to limit himself to the exact construction beion shown by way of
illustration
If the coal is too coarse or if masses of coke form which will not pass under
the air pipe it may be broken up with a hand bar or other mechanical means.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manuer the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. The herein described method of burning coal which consists in confining the
ccal in a chamber, coking the coal by heat externally applied thereto, causing the
coked coal and the expelled gases to pass continuously though said opening in a
thin layer and forcing an through and layer of coked coal at said opening,
whereby said gas is burned in contact with said coked coal.
2. The herein described furnace having coal pockets on opposite sules, feed
openings in the bottom of said pockets connecting them with the combustion
chamber of said furnace, an air blast pipe adjacent to each of said openings having
jets directed inward toward the centic.
3. The herein described furnace having a coal pocket in the side thereof, a feed
opening in the bottom of said pocket connecting the same with the combustion
chamber of the furnace, an an blast pipe immediately above said opening and

page_text: having jets directed vertically downward and jets directed inward toward the centre
of said fui nace.
4. The herein described furnace having a coal pocket at the sides thereof
separated from the combustion chamber by a wall, a narrow opening in the lower
portion of said pocket through which the coal enters the furnace in a thin layer,
a perforated air blast pipe forming one side of said opening and a grate on which
said coal falle..
5. The herein described furnace having a coal pocket on each side thereof con-
necting with the combustion chamber of said furnace by a narrow opening, au
inwardly inclined giate immediately below each of said openings, the said an
blast pipes having a series of holes discharging directly downward, and a series of
holes dnected ward substantially parallel with said inclined grate.
6. The herein described furnace having a pocket for receiving the fuel, said
pocket having a narrow opening through which the fuel 18 discharged into the
furnace in a thin layer and a perforated air blast pipe forming the upper part of
said opening.
7. The heroin described furnace having a side wall resting on a perforated air
blast pipe, a buttress outside of said wall, the space between said buttress and said
wall forming a coal receiving pocket having an opening beneath said pipe con-
necting with the combustion chamber of the furnace, and a perforated grate on
which the fuel falls after passing through the opening.
Dated this 10th dow of Tal
1000
WM. P. THOMPSON & Co.,
Agents.