IMPROVEMENTS IN SMOKE-CONSUMING FURNACES
Year: 1855

page_text: LETTERS PATENT to John William Sloughgrove and James Henry
Wheatley, of Windsor Street, Islington, Engineers, for the Invention of
"IMPROVEMENTS IN SMOKE-CONSUMING FURNACES."
Sealed the 7th September 1855, and dated the 7th March 1855.
PROVISIONAL SPECIFICATION left by the said John William Slough-
grove and James Henry Wheatley at the Office of the Commissioners of
Patents, with their Petition, on the 7th March 1855.
We, JOHN WILLIAM SLOUGHGROVE and JAMES HENRY WHEATLEY, of
Windsor Street, Islington, Engineers, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SMOKE-CONSUMING FURNACES" to be as follows:-
The first of these improvements in smoke-consuming furnaces consists in
fitting beneath the furnace bars a moveable plate, so as to shut off the com-
munication between the ash-pit and the flue or chimney. The accompanying
Drawing represents an outline of this part of our Invention. A is the dead
plate; B, one of the furnace bars; C, a bridge at the end of the bars; D, a
plate beneath the grate. The dead plate A is supported by pins, or other
means, so as to move easily about its points of support; the furnace bars are
supported by a framework or cradle, moveable upon its axis, so that the fire
grate may be raised or lowered by means of a- lever extending in front of the

page_text: ash-pit. The plate D is secured to the furnace bars B by the rod or lever E,
so that when the grate is moved either up or down, by means of the lever the
plate is likewise moved, and either opens or cuts off the communication
between the ash-pit and the flue or chimney. As shown in the Drawing, the
passage from the ash-pit to the flue is partly open, but may be completely
closed by depressing the lever attached to the bars B, which causes the front
end of the bars to descend, and raises the plate D and also the bridge C until
it touches the lower part of the boiler. The air necessary for the combustion
of the fuel now passes up through the fuel at the front part-of the furnace and
through the incandescent fuel.at the back of the grate. In passing through
the highly heated fuel, the combustible gases of the smoke are ignited, and the
invisible vapours only escape by the chimney.
The second part of our Invention is as follows:-The furnace is fitted with
two sets of fire bars, placed behind each other; between them is a space, in
which a moveable screen or bridge is worked; the screen is made of two
perforated metal plates, the sides and top of the bridge being closed, and the
bottom left open to admit a current of air between the plates. The shape of
the screen or bridge will be made in accordance with the form of the furnace
and boiler, and it is to be raised or lowered by means of a lever, a rack and
pinion, a quadrant, or other mechanical arrangement. Another screen or
bridge, similar to the foregoing, is fitted at the end of the second set of fire bars,
next the chimney shaft or flue; this screen may be worked by similar means
to the other; or one screen may be actuated by a tube attached to the lever or
rack, and the other by a rod fitted within the tube. These screens when raised
form a double bridge, the fire burning in front of each. The fire nearest the fluc
is supplied with fuel by lowering the front screen and pushing back a portion
of the incandescent fuel from the outer fire; the screen or bridge is then raised.
When coal is thrown upon the outer fire, the smoke and gaseous products
arising from its combustion pass through the screen and over the second fire,
by which they are ignited, and consumed. The object of the second screen is
to prevent the gaseous matters passing over the incandescent fuel too quickly
and escaping into the chimney unconsumed. By the foregoing arrangement
the visible and combustible gases are entirely consumed, the heated air and
invisible vapour alone passing off by the chimney. In some cases the second
screen or bridge will not be required, but we reserve the right to vary
the
details of this Invention as required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John William Sloughgrove and James Henry Wheatley in
the Great Seal Patent Office on the 7th September 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
WILLIAM SLOUGHGROVE and JAMES HENRY WHEATLEY, of Windsor Street,
Islington, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of March, in the year of our Lord One
thousand eight hundred and fifty-five, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
John William Sloughgrove and James Henry Wheatley, Her special licence
that we, the said John William Sloughgrove and James Henry Wheatley,
our executors, administrators, and assigns, or such others as we, the said
John William Sloughgrove and James Henry Wheatley, our 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 vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN SMOKE-CONSUMING FURNACES," upon
the condition (amongst others) that we, the said John William Sloughgrove
and James Henry Wheatley, by an instrument in writing under our hands and
seals, or under the hand and seal of one of us, 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 we, the said John William Sloughgrove and Janies
Henry Wheatley, do hereby declare the nature of our said Invention, and
in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:―
The object of our Invention is to thoroughly consume the combustible gases
which emanate from burning coal, and are usually allowed to pass off into the
atmosphere, forming those dense volumes of smoke which are so frequently
observed issuing from engine shafts or chimnics, funnels of steam vessels, and
other places where furnaces are used. These improvements are applicable to
the furnaces of all varieties of boilers, whether plain or tubular, brewers' and
sugar refiners' furnaces, bakers' ovens, chemical works, and other places where
it is desirable to prevent the emission of visible smoke. The improved furnace

page_text: is fitted with two sets of fire bars, slightly inclining upward towards the back.
At the end of the further set of bars is fitted a perforated bridge, and this may
be made moveable or not. Below this bridge a door is fitted, in order to afford
access to the space behind the bridge, for the purpose of cleaning out the same.
Between the front and back set of fire bars is fitted a moveable bridge or
partition, attached to a lever, so that it may readily be moved up and down by
the stoker or person in charge of the furnace. When the bridge or partition
between the bars is lowered, access may be readily had to the back or further
set of bars, and while the furnace is at work a brightly glowing fire is kept on
this grate by pushing back the incandescent fuel from which the gas has
escaped from the front grate to the back. After the further grate has been
supplied, the bridge is lifted, and all communication cut off between the two
fires except through the holes or perforations in the bridge or diaphragm. The
front fire is supplied with fuel in the ordinary manner. Now, when fuel is
thrown on to the fire a large quantity of unconsumed gases and smoke are
immediately evolved, which, instead of being allowed to escape at once to the
flue or shaft, are arrested by the perforated bridge. This is so constructed that
a current of air is caused to be intimately mixed with the smoke, which then
passes through the perforations in a series of streams on to the second fire;
this being kept in a state of vivid combustion, the inflammable gases contained
in the smoke are flashed into flame, which circulates round the boiler, imparting
its heat thereto, and effecting a saving of fuel, at the same time nothing but
invisable vapour escapes from the chimney.
In the Drawings accompanying this Specification our improvements are
shown applied to boilers of various forms of construction.
Figs. 1 and 2 represent longitudinal sections of a stationery boiler. A is the
boiler; B, the brickwork which supports the same; C, the furnace; D and E,
two series of fire bars. These incline slightly upward towards the back of the
furnace, as shewn in the Figures. The fire bars are supported by the bearing
bars F, F, and the bridge plate G. H is the dead plate; L, a perforated bridge,
which may be made either of fire-clay or of metal thickley coated with fire-clay.
The perforations are made of a taper or conical form, the larger part being
towards the flue. Between the sets of fire bars D and E is fitted a diaphragm
K, which separates at will the after part of the furnace from the front part.
This diaphragm is a double metal plate, closed at the top and sides, but open at
the bottom; it is fitted in guides, which are secured to the sides of the ash-pit,
so that it may slide freely up and down. The back and front plates of the
diaphragm are perforated with holes h, k, but they are not placed opposite each
other; the rows of holes in the back plate are made between those in the front

page_text: plate. This arrangement is for the purpose of dividing the streams of smoke,
and more effectually mixing them with the current of atmospheric air that
passes up through the bottom of the diaphragm. A lever L, secured to the
shaft M, gives motion to the diaphragm; this lever is made sufficiently heavy
to counterpoise the greater portion of the weight of the diaphragm, so that it
may be easily raised by the hand. The diaphragm is connected to the lever
by two links, one of which is seen at N. This arrangement admits of the
diaphragm moving in a perpendicular direction, notwithstanding the curve
described by the end of the lever L. M is a quadrant, for the purpose of
adjusting the position of the lever L. The furnace is fitted with what we term
a trunk front O, that is to say, the iron-work of the front projects, as shown in
the Drawing, and is connected with the plate P, in order to afford a com-
munication between the furnace and the space below the fire bars. This
arrangement is for the purpose of carrying off the small quantity of smoke that
would otherwise hang near the furnace door, in consequence of its being
beyond the influence of the draught, but by having this passage for its exit, it
is rapidly conveyed below the fire bars D, and up through the fire. The fire
bars E are supplied with fuel from the front fire; and to do this the diaphragm
is lowered, as shown by Fig. 1, and a sufficient quantity of incandescent fuel is
pushed back upon the bars E. It should be observed that this fuel must be in
a state of intense ignition, but not giving off any smoke, and that it is kept
supplied in this manner. The diaphragm is then raised, as shewn by Fig. 2,
and the coal is thrown upon the front fire in the ordinary manner; the smoke
arising from its combustion passes through the holes of the front plate of the
diaphragm, where it is mixed with the current of air which passes up between
the plates. The smoke and air are carried in divided streams through the back
plate of the diaphragm on to the bright fire upon the bars E, by which they are
instantly flashed into flame, which passes through the perforated bridge I; this
perforated bridge prevents the smoke and air passing off to the fluc before it
is thoroughly ignited, and this bridge may also be made moveable, like the
diaphragm K.
Figs. 3 and 4 represent the Invention applied to a marine boiler; the
different parts are marked with similar letters of reference to those in Figs. 1
and 2. The lever L does not interfere in any way with the projecting front,
but passes up by the side of it, close to the wall or side of the ash-pit.
Although we have shown the diaphragm L as fitted with a lever for actuating
the same, other mechanical means may be used to effect the object.
Figs. 5 and 6 show the application of the improvements to a Cornish boiler.
In this arrangement the diaphragm is of a semicircular form, and has cogs or

page_text: teeth k² cast upon the outer surface; is a pinion in gear with the teeth k²;
the pinion is keyed to a shaft or rod l', which is carried out to the front of the
boiler, and upon its outer end a handle is fitted, by which the diaphragm may
be raised or..lowered at pleasure. Where desirable, both the diaphragms k
and may be made to move together; this may be done by having cast
with teeth, similar to k, and fitting the rod '', to work it in connexion with k,
as before described.
Figs. 7 and 8 represent a modification of the foregoing improvements. In
this case the products of combustion are made to pass from the first fire
down beneath the second set of fire bars, and up through that fire to the flue.
Fig. 7 shews the diaphragm K down, in which position the smoke would
at once pass off to the flue or shaft. Fig. 8 represents the arrangement
with the diaphragm raised. The. products of combustion now take the course
indicated by the arrows, and pass through the back fire, which is kept in
a state of intense ignition, thereby consuming all inflammable matter, and
allowing only invisible vapour to escape. The other parts of the details are
sufficiently obvious, and do not require describing in words. This arrangement
inay be applied to any form of construction of furnace.
Another modification of our improvements consists in fitting beneath the
furnace bars a moveable plate, in such manner as to shut off the communica-
tion between the ash-pit and the flue or chimney, and thereby causing the air
necessary to support combustion of the fuel to ascend through the fuel at the
front of the fire bars, and descend through the incandescent fuel at the back,
carrying with it the smoke or unconsumed gases. In this arrangement the
fire bars are supported in a frame or cradle, moveable upon an axis, so that
the fire grate may be raised or lowered by means of a lever extending in front
of the ash-pit.
The diagram, Fig. 9, represents an outline of this part of our Invention.
A is the dead plate; B, one of the furnace bars; C, a bridge at the back of
the furnace; D, a moveable plate beneath the grate. The dead plate A is
supported at a', so as to move readily about its points of. support; the
furnace bars B move in a similar manner about the axis b'. Beneath the
fire bars is fitted the plate D, moveable on an axis at d¹, and connected
to the fire bars by a rod or lever E. When the lever attached to the frame-
work of the fire bars is pushed down, it causes the after part of the fire bars
to be elevated, and this action carries the bridge C close up to the bottom
of the boiler, and likewise draws the plate D up to and in contact with
the fire bars; the effect of this is, that a current of air is drawn rapidly
through the-fuel in front of the bars, which, owing to the rarefaction of the air

page_text: in the chimneys, descends through the burning mass at the back of the grate,
igniting all combustible matter, and allowing only invisible vapour to escape.
The fire may be checked by partly depressing the lever by which the plate D
is lowered, as shown in the Figure; this allows a current of air to pass into
the flue or chimney, which is thereby cooled, and the consumption of fuel
retarded.
Having described the nature of our Invention, and the manner of carrying
the same into practical use, we desire it to be understood that we do not
confine ourselves to the precise arrangement of the details as herein described
and shown, as the same may be varied without departing from the Invention;
but what we claim, and desire to secure under the herein-before in part recited
Letters Patent is,-
Firstly, the mechanical arrangements for consuming smoke, as shown and
described in reference to Figs. 1 to 6 of the accompanying Drawings, or any
mere modification thereof.
Secondly, the arrangement for consuming smoke, as shewn by Figs. 7 and 8,
and herein-before described, or any mere modification thereof.
Thirdly, the arrangement for consuming smoke, as shewn by Fig. 9, and
before described, or any mere modification thereof.
In witness whereof, I, the said James Henry Wheatley, have hereunto set
my hand and seal, this Seventh day of September, One thousand eight
hundred and fifty-five.
5
JAMES HENRY WHEATLEY. (L.S.)
Witness,
CHARLES BARLOW,
Patent Agent,
89, Chancery Lane, London.