IMPROVEMENTS IN THE CONSTRUCTION OF BOILER AND OTHER FURNACES
Year: 1853

page_text: LETTERS PATENT to Robert Christopher Witty, of 1, Portland
Place, Wandsworth Road, in the County of Surrey, Engineer,
for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF BOILER
AND OTHER FURNACES."
Sealed the 1st February 1854, and dated the 6th December 1853.
PROVISIONAL SPECIFICATION left by the said Robert Christopher
Witty at the Office of the Commissioners of Patents, with his
Petition, on the 6th December 1853.
I, RICHARD CHRISTOPHER WITTY, of 1, Portland Place, Wandsworth
Road, in the County of Surrey, Engineer, do hereby declare the nature
of my said Invention for.." IMPROVEMENTS IN THE CONSTRUCTION OF BOILER
AND OTHER FURNACES" to be as follows:-
These improvements have for. their object the burning of coal in such
manner as not to evolve smoke into the chimney or atmosphere, and:
they consist of constructing at the end of the fire bars a bridge of fire
brick or moulded lumps, such bridge being made with numerous
passages through it, so that when desired, the whole of the products
from the fire may be caused to pass through these passages in place of

page_text: passing over the bridge. Above the bridge there is an opening for the
passage of the products from the fire, which opening can be closed at
any time by a slide or other form of fire tile, or other suitable material.
By this arrangement, when the fire is about to be supplied with
fresh coal, the ordinary passage over the bridge may be closed, and the
products from the fire caused to pass through the perforated bridge,
which being highly heated by the previous action of the fire, will,
together with a supply of warm air beyond the bridge, cause the pro-
ducts from the fresh fuel to be ignited, and as the fire becomes bright,
the ordinary passage over the bridge may be again opened, and the
bridge will become again very hot by the action of the bright fire.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Christopher Witty in the Great Seal
Patent Office on the 3rd June 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ROBERT CHRISTOPHER WITTY, of 1, Portland Place, Wandsworth Road,
in the County of Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of December, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said Robert Christopher Witty,
Her special licence that I, the said Robert Christopher Witty, my
executors, administrators, and assigns, or such others as I, the said
Robert Christopher Witty, my 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 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 for "IMPROVEMENTS IN THE CONSTRUCTION OF BOILER AND OTHER
FURNACES," upon the condition (amongst others) that I, the said Robert
Christopher Witty, by an instrument in writing under my hand and

page_text: 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 Scal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Robert Christopher Witty, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof (that is to say) :-
This Invention consists of a mode or modes of constructing boiler and
other furunces for the purpose of causing the smoke and other gascous
products arising from the burning of coal in such furnaces to be con-
sumed, and thus preventing the smoke from passing into the chimney
or atmosphere. For this purpose I construct a furnace with a per-
forated bridge at the end of the fire bars, and a slide door or other con-
venient means for closing the opening above the bridge. The bridge
may be made of fire brick or moulded lumps, or any other fit materials,
constructed or put together in such a manner that the bridge shall have
numerous passages through it for the smoke and other products arising
from coal supplied to the fire to pass through when the opening above
the bridge is closed. The opening above the bridge is furnished with
a sliding door or other convenient nieans for closing it, so that it may be
kept open for the passage of the products arising from the fire at those
times when the fire does not produce smoke; and the opening can be
closed at any time, when by reason of a supply of fresh fuel, or any
other cause, smoke shall be evolved from the burning fuel. The door
or slide may be made of fire tile or any other suitable material, so that
it may be able to sustain the action of the heat to which it may be
exposed. In using a furnace constructed in this manner, some of the
thoroughly ignited fuel which has ceased to give out smoke should be,
from time to time, pushed back against or near to the bridge, so that
the bridge may be made as hot as conveniently may be, for the purpose
of heating the smoke and gaseous products which shall from time to
time be caused to pass through the orifices or passages of the bridge;
and when the fire is about to be supplied with fresh coal or other fuel

page_text: producing smoke, the passage over the bridge is closed, so that'the
smoke and other griseous products arising from the fresh fuel in the front
of the fire may in its passage to the orifices or openings of the bridge
be caused to pass more closely over the top of the hot fire at the back
of the furnace, and may then pass through the orifices or passages
made through the bridge, which being highly heated by the previous
action of the fire, will further contribute to raise the temperature of the
smoke and other gaseous matters, so that when they come in contact
and become mingled with a supply of warm air, admitted beyond the
bridge for this purpose, the smoke and other products arising from the
fresh fuel may be ignited and consumed before they can reach the
chimney or atmosphere. When the combustion of the fresh fuel
has proceeded so far that it forms a portion of the bright fire, the
passage over the bridge is again opened, so that the bridge may bo
again made very hot by the action of the bright fire.
For the purpose of more clearly explaining my said Invention, and
the manner of performing it, I have in the accompanying Drawings
shewn the manner in which it may be applied to a steam boiler furnace.
Figure 1 shows a longitudinal section; Figure 2, a transverse section
(taken through the dotted line y, z, Figure 1); and Figure 3, a front
view of a steam boiler furnace, which being for the most part of an
ordinary construction, does not therefore require a description, except so
far as respects the combination of parts constituting my Invention. In all-
these Figures similar parts are marked with similar letters of reference.
a is a bridge of fire clay, having numerous orifices or passages through
it; and 6 is a passage for a supply of air from the ash pit to the back
of the bridge. The orifices or passages through the bridge may be
round, square, or any other shape which may be found most convenient
in the manufacture of the particular material of which it may be made.
c is a slide or trapdoor by means of which the opening above the bridge,
that is to say, the open space between the top of the bridge and the
bottom of the boiler, may be closed. The slide is moved up or down by
the levers d, d', which are mounted upon the axis e. The further end
of the lever d is attached to a link f, which is connected with and acts
on the slide. By this arrangement it will be seen that if before sup-

page_text: plying fresh coals to the furnace, the slide c is raised, all the smoke and
gaseous products from the fire, in place of passing, over the bridge will
pass through or near to the hot fire in front of the bridge, and also
through the holes or passages in the hot bridge, and being thus highly
heated, they will upon coming into contact with the current of air
behind the bridge be in a better state for causing them to be moro
completely consumed. After a supply of fresh fuel shall have ceased
to give out smoke, the slide c is then to be lowered, so that the bridge
after being cooled by the passage of the currents of smoke and gas
through it may become very hot, and be thereby in a. better condition
to heat the smoke and other products evolved from the next supply of
fuel to the furnace. Although the Invention is only shown in tho
Drawings to be applied to a steam boiler furnace, it may be applied
to all similar furnaces, that is, to furnaces which may be constructed
with bridges and spaces above the bridges for the passage of the flame,
smoke, or other products of combustion; and the shape and size of the
bridge as well as of the opening above the bridge, and the slide or door
for closing such opening may be varied according to the form, size, and
construction of furnace to which the Invention may be applied. So also
the slide or door used for closing the opening above the bridge may be
made to slide backwards and forwards horizontally in a groove, or may
be hung upon hinges or otherwise arranged, so that the fireman may
with facility open and close the opening or space above the bridge as
shall from time to time be requisite in working the furnace as above
described.
Having thus described the nature of my said Invention, and the
manner of performing the same, I declare that I do not claim the conl-
struction of a furnace with either a perforated bridge, or with an air
passage behind the bridge, and without any means of closing the opening
or openings above the bridge; nor do I claim any of the other elements
or parts of a furnace which I have above described or shewn in the
Drawings as being separately any part of my said Invention; and that
what I claim as of my said Invention in the construction of a boiler or
other furnace is, the combination of a perforated bridge, and a door,
slide, or stop, for the purpose of from time to time opening and closing

page_text: the space, opening or openings, above the bridge, in manner and for the
purposes above described.
In witness whereof, I, the said Robert Christopher Witty, have
hercunto set my hand and seal, this Twenty-first day of March,
in the year of our Lord One thousand eight hundred and fifty-
four.
Witness,
LEYSON W. KING,
Sol',
50A, Lincoln's Inn Fields.
ROBT. C. WITTY. (L.S.)