IMPROVE- MENTS IN FURNACES FOR THE PREVENTION OF SMOKE
Year: 1860

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN FURNACES FOR THE PREVENTION OF SMOKE."-A communication
from abroad by Jules Poivret, of Paris, in the Empire of France, Manu-
facturer.
Sealed the 8th June 1860, and dated the 17th February 1860.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 17th February 1860.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN FURNACES FOR THE PREVENTION OF SMOKE," a communication
from abroad by Jules Poivret, of Paris, in the Empire of France, Manufacturer,
to be as follows:-
This Invention relates to a peculiar construction and arrangement of
furnace, whether for stationary, locomotive, or marine boilers, or for other
purposes, whereby a perfect combustion of the gases is obtained and the pre-
vention of smoke effected. According to this Invention it is proposed to so
construct the furnace that the fuel will form one continuous mass from the

page_text: front to the back end of the furnace, the continuity being maintained as the
fuel burns away by mechanical means, as, for example, by vertically rotating
fire-grates carried on horizontal axes, by endless chains of fire-bars placed at
an inclination, or by ordinary fire-bars at such an inclination that the fresh
fuel will descend by its own gravity and take up the place of the burnt fuel, a
supply of fresh fuel being maintained in a feeding hopper above or at the upper
end of the grate. In front of the moveable grate in land furnaces there may
be a second or fixed grate composed of short fire-bars, which serve to support
the fuel as it is driven down by the occasional rotation or traversing of the
moveable grate. A hanging bridge is also placed in front of the main grate,
which bridge may be either hollow or solid, and supplied or not with a current
of feed water or cool air. In locomotive engines the shaking of the engine
will generally effect the gradual and steady descent of the fuel, but an arrange-
ment should be provided for vibrating the grate when the engine is
standing.
By the system and contrivances above described the gases from the green or
fresh fuel will pass direct through the incandescent fuel of the mass, and will
be thereby effectually consumed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 17th August 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JoHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain, Gentle-
man, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of February, in the year of our
Lord One thousand eight hundred and sixty, in the twenty-third year. of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Henry Johnson, Her special license that I, the said
John Henry Johnson, my executors, administrators, and assigns, or such
others as I, the said John Henry Johnson; my executors, administrators,
or 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 law-
fully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Invention.

page_text: for "IMPROVEMENTS IN FURNACES POR THE PREVENTION OF SMOKE," a communication
from abroad by Jules Poivret, of Paris, in the Empire of France, Manufacturer;
upon the condition (amongst others) that I, the said John Henry Johnson,
by an instrument in writing under my hand and seal, should particularly
describe and 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 John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and:
to the letters and figures marked thereon, that is to say :-
The said Invention relates to a peculiar construction and arrangement of
furnace, whether for stationery, locomotive, or marine boilers, or for other
purposes, whereby a perfect combustion of the gases is obtained, and the pre-
vention of smoke effected. According to this Invention it is proposed to.
construct the furnace in such a manner that the fuel will form one continuous:
mass from the front to the back end of the furnace, the continuity being main-
tained as the fuel burns away by mechanical means, as, for example, by vertically.
rotatory fire-grates carried on horizontal axes, by endless chains of fire-bars.
placed at an inclination, or by ordinary fire-bars at such an inclination that the
fresh fuel will descend by its own gravity, and take up the place of the burnt.
fuel, a supply of fresh fuel being maintained from a feeding hopper above or
at the upper end of the grate. In front of the moveable grate in land furnaces.
there may be a second or fixed grate composed of short fire-bars, which.serve
to support the fuel as it is drawn down by the occasional rotation or traversing
of the moveable grate. A hanging bridge is also placed in front of the main..
grate, which bridge may be either hollow or solid, and supplied or not with a
current of feed water or cool air. In locomotive engines the shaking of the
engine will generally effect the gradual and steady descent of the fuel, but an
arrangement should be provided for vibrating, the grate when the engine. is
standing.
By the system and contrivances above described the gases from the green or
fresh fuel will pass directly through the incandescent fuel of the mass, and
will be thereby effectually consumed.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures ou the Sheet of Drawings hereunto annexed, the

page_text: same letters of reference indicating corresponding parts throughout all the
corresponding Figures.
Figures 1 and 2 of the accompanying Sheet of Drawings represent respec-
tively a longitudinal vertical section and end elevation of a stationary boiler fur-
nace, constructed according to this Invention. Figures 3 and 4 represent similar
views of a furnace suitable for dye works, constructed on the same principle.
Figure 5 represents the application of this principle also to a locomotive boiler
furnace. The rest of the Figures are details which I shall herein-after fully
describe and refer to. The fire-place in Figures 1 and 2 is provided with a
front circular moveable grate E, and a lower grate C mounted on hinges,
and capable of being let down into the position indicated by blue lines for
facilitating the emptying of the furnace when desired. The grate E, mounted
on a central axis, is actuated by a lever handle f, provided with a pall, which
takes into the teeth of a ratchet wheel keyed on to the axis of the grate, so that
the rotatory movement of the grate, and consequently the descent of the fuel
contained in the hopper, depend upon the use of this lever. The hinged
grato C is connected with a system of jointed levers provided with bandles, as
shewn at H, convenient to the hand of the attendant. A tube or hollow
bridge F, forming the bottom of the front wall of the furnace A, is kept con-
stantly filled with water, whereby this part of the furnace is protected from the
destructive action of the fire, whilst at the same time it serves to heat the
water of the generator or boiler B. The air entering the grates C and E, as
shewn by the arrows, produce at this central point of the furnace or continuous
current or draught, which draws to and maintains at that part all the gases
developed by the heat, and assists their combustion in sucli a manner that they
are entirely consumed by the time they arrive at the boiler. The coal or
other combustible contained in the hopper, and subjected to the feeding and
steady subsidence produced by the occasional turning of the grate E, may be
equally acted upon by the modified form of grate illustrated at Figure 6.
This grate consists of endless chains E', passed round polygonal rollers M, and
carrying the bars which form the fuel-bearing surface. The other Figures on
the Sheet of Drawings represent examples of various modifications, both as
regards the grate C (Figure 1), which forms the bottom of the furnace, and
the front grate E of the same Figure, which supplies the fuel to the furnace.
I may here observe that these modifications are equally applicable to furnaces
of all kinds.
.
In Figures 3 and 4, A is the brickwork of the furnace; B, a portion of the
boiler; C, a portion of a reservoir; D, the grate mounted on the carriage D';
and E, the moveable grate serving to break up the coal in the hopper, and

page_text: nace.
supply it to the furnace. The bars of this. grate are fixed in a moveable
frame F mounted on a shaft, which is secured to two cheeks, the upper part
of the frame forming a plate. The cheeks G, which are of cast iron, are
fixed to the front of the furnace, one on each side of the frame F. They are
united by a plate H, which descends to the level of the opening, through
which the fuel is pushed into the furnace. The arms J are fixed to the sides
of the frame F, and are connected by a cross bar, which serves as a handlo
for actuating the grate E. In order to supply fuel to the furnace, it is
simply requisite to impart a to-and-fro motion to the arms J, whereupon
the grate E will oscillate to and fro, and force in the fuel as fast
as it descends from the fuel space above; K is the water heater supplied by
the pipe L from the reservoir C; N is a door through which combustibles are
introduced into the furnace M, when lighting the fire; O are slots made in the
checks G, in which the ends of the supporting shaft or spindle of the grate E
rest, so that facility is afforded for raising the grate when the carriage D' and
grate D are required to be run out for the purpose of emptying the fur-
The frame F, the grate E, the cheeks G, and the plate H combined as
shown in Figure 3, form a hopper, into which the fresh fuel is supplied. The
bars of the frame F may be replaced by a plate, the draught of air being
regulated by a damper. In erecting large furnaces on this principle, two or
more frames may be contained between the same pair of cheeks, disposed one
above another. The pipe K is supplied with water or air for the purpose of
preventing the coal in the hopper above the entrance to the furnace from
becoming coked too soon, and producing gas which would escape at the front
5 of the furnace in place of being drawn therein and burnt. It is highly desirable
that the coal in the hopper and the incandescent fuel in the furnace should
form one uninterrupted mass, which may be readily effected by imparting
occasionally a gentle vibratory motion to the arms J, J. If not worked by
machinery, this frame should be actuated by the stoker as often as he would
require to supply fresh fuel to an ordinary furnace, and by attending to this
simple duty the entire prevention of smoke will be effected. The bottom
layer of fuel in the hopper becomes heated and coked immediately in front of
the mouth or entrance to the furnace and beneath the water or air tube K.
The gases emitted during this coking of the coal are drawn inwards by tho
entering air, and are entirely consumed by being carried over the surface of the
incandescent fuel in the bottom of the furnace. As the grate D contains
nothing but incandescent fuel, it is easily kept clean, and the draught main-
tained free and unimpeded. In the locomotive boiler furnace, Figure 5, A
represents the firo box; B, a portion of the boiler; C, a part of the tender;

page_text: D, the bottom grate or fire bars; F, the moveable frame supported by a trans-
verse shaft or spindle resting in the side cheeks G, and containing the grate
bars E at its lower end; J are the arms for vibrating the frame, so as to force
the fuel beneath the water chamber or tube into the body of the furnace L;
H is the front of the boiler, which with the cheeks G and frame F constitutes
the fuel hopper. The water space K is supplied by a pipe opening into the
side of the boiler, or into the tender. Figures 7 and 8 represent respectively
a detail side elevation and transverse section of a fire-bar, specially adapted to
this system of furnace, as by reason of its inclined surface the incandescent
fuel thereon will always have a tendency to bear against the front part K of
the furnace.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent, is,-
First, the general constructions and arrangements of furnaces or fire-places
for effecting the perfect combustion of the fuel and preventing the formation
of smoke, as hercin-before described.
Second, the contrivances herein-before described for causing the uncon-
sumed gases generated in the furnace to pass into a mass of incandescent fuel,
or over the surface of the same, with a view to their perfect combustion.
Third, the peculiar construction and arrangement of moveable grates, for
the purposes herein-before described.
Fourth, the application and use at or near the central part of the furnace of
a tube or chamber supplied with water or air, or a mixture of both, for the
purposes herein-before described.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Seventeenth day of August, One thousand eight
hundred and sixty.
J. HENRY JOHNSON. (L.S.)