IMPROVEMENTS IN FURNACES FOR STEAM ENGINES
Year: 1855

page_text: LETTERS PATENT to William Burtt Wilton, of Lowestoft, in the County
of Suffolk, Engineer, for the Invention of "IMPROVEMENTS IN FURNACES
FOR STEAM ENGINES."
Sealed the 6th November 1855, and dated the 8th May 1855.
PROVISIONAL SPECIFICATION left by the said William Burtt Wilton at
the Office of the Commissioners of Patents, with his Petition, on the
8th May 1855.
I, WILLIAM BURTT WILTON, of Lowestoft, in the County of Suffolk, En-
gineer, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN FURNACES FOR STEAM ENGINES" to be as follows:-
My Invention of improvements in furnaces of steam boilers consists in
so arranging the different parts of the furnace that the visible smoke
arising from the combustion of the fuel may be burnt before it reaches
the shaft or funnel. The back of the dead plate is bent downwards at
right angles to the horizontal surface. The vertical part has an opening
or aperture made in it, which extends across the furnace from side to
side of the furnace bars; this opening may be closed when required by a
damper or door fitted in front of it. The bearing bars are cast with
apertures through them, in which the furnace bars are fitted. The
furnace bars are made of malleable iron, and hollow throughout their
Price 8d.]

page_text: length. When fitted in their places, the openings of the bars are
opposite the aperture in the lower part of the dead plate. The bridge
is supported by an iron plate, bent twice at right angles; the lower part
has an opening to receive the furnace bars, similar to that in the dead
plate. A door is fitted beneath the bridge plate, so as to prevent atmo-
spheric air passing through the ash-pit to the chamber at the back of
the bridge; by means of this door also the ashes at the back of the bridge
may be readily removed. By the foregoing arrangement, the air as it
passes through the hollow bars becomes highly heated, and when it
escapes into the chamber or space at the back of the bridge the com-
bustible gases are ignited, without lowering the temperature of the
furnace.
A further supply of oxygen is furnished by means of air tubes
fitted in the smoke box doors; these tubes convey air to the back of the
furnace so as to complete the ignition of the combustible gases. The
air thus conveyed is heated to some extent in its passage through the
tubes of the furnace. Small doors are made at the lower part of the
smoke box doors, by opening which the fire may be damped without
opening the furnace doors or using any other damper. The aperture in
the dead plate is fitted with a damper, which is closed when the fires
are lighted, and kept so until they burn clear. The foregoing arrange-
ment of furnaces is applicable to marine or stationary boilers. I reserve
a right to vary the details of my Invention.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Burtt Wilton in the Great Seal Patent Office
on the 8th November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BURTT WILTON, of Lowestoft, in the County of Suffolk, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of May, 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
me, the said William Burtt Wilton, Her special licence that I, the said
William Burtt Wilton, my executors, administrators, and assigns, or
such others as I, the said William Burtt Wilton, my executors, admini-
strators, and assigns, should at any time agree with, and no others, from

page_text: my
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 FURNACES
FOR STEAM ENGINES," upon the condition (amongst others) that I, the said
William Burtt Wilton, by an instrument in writing under 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 William Burtt Wilton, do hereby declare
the nature of my 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 my Invention is to prevent the emission of visible smoke
from the furnaces of land and marine steam engines. The legislature
having prohibited the use of furnaces for stationary engines which send
forth visible smoke, it is of the highest importance that the best means
of raising steam without causing an annoyance by smoke should be
known and adopted. And it is equally important that smoke should be
consumed in marine furnaces, although this is not yet made compulsory
by law; because, in the first place, it is highly essential that vessels
engaged in war should be able to manœuvre without being observed
and watched by the enemy; and as smoke soils the sails and rigging,
many sailors have a great objection to serve in war steamers.
My improved arrangements will be found peculiarly well adapted for
marine furnaces, their practical trial having already given much satis-
faction. I effect these objects by a peculiar arrangement of the fire
bars, bridge, air tubes, and smoke box doors, by which a sufficient
quantity of atmospheric air is supplied to the burning fuel, thus insuring
the complete combustion of the inflammable gases before they reach the
shaft or funnel. The furnace bars are made hollow, and of the form
herein-after shewn and described. These bars are supported by hollow
bearing bars, and by a dead plate and bridge plate, made to receive the
ends of the fire bars without checking the passage of the air through the
bars. The dead plate is fitted with a damper, in order that the current
of air through the bars may be stopped during the time of raising steam.
The bridge plate is of iron, and supports a bridge made of bricks of fire
clay. Beneath the bridge plate is fitted a door, by which access is haḍ

page_text: to the back of the bridge to clear the space beyond of ashes when
required. The smoke box doors are each perforated with an aperture,
in which is inserted a tube communicating with the tubular part of the
boiler, and to be used as occasion may require; these tubes convey air
to the back part of the furnace, and ignite any portion of inflammable
gas that may have passed to the tubes unconsumed. The lower part of
the smoke box doors are made to open when required, so that the fire
may be checked without opening the furnace doors. The arrangement
herein described and shown is peculiarly adapted for marine purposes as
well as for land engines, and not only effects a saving in fuel, but also
saves the wear of the vessel's sails, which are at present much injured,
as well as rendered unsightly, by smoke from the funnel.
In the Drawings accompanying this Specification L shew the applica-
tion of my Invention to a marine boiler and to a stationary boiler, and
details of the different parts: Fig. 1 is a vertical section of a marine
boiler; and Fig. 2 is a front view of the same, partly in section. A is
the furnace; B, the boiler; C, the tubes through which the gaseous
matters pass to the smoke box D; E, the fire bars; F, the bearing bars;
G, the dead plate; H, the bridge plate; I, the bridge; K, a door opening
from the ash-pit to the space behind the bridge; L, the smoke box doors;
M, air tubes; N, doors for damping the fire. The fire bars E are made
of malleable iron, and hollow throughout, as shewn by.the cross section,
Fig. 3, and longitudinal view, Fig. 4. The lower part of the bar is
formed of a plate of malleable iron 5/16ths of an inch thick, welded to
a thick bar of the same metal, upon which, the fuel rests; the projecting
ends of the bars are chamfered off, as shown by Fig. 4, and upon these
ends the bars rest. When in their places, the front ends of the first
series of fire bars rest upon the dead plate G, the shape of which is shewn
by the section, Fig. 5. The back part a is bent downward at right
angles to the horizontal part b; the upper part of the bend at c is
chamfered off at an angle, upon which surface the fire bars rest. The
lower part of the dead plate is made with an opening d to allow the
passage of the air through the fire bars; a damper e, shewn in front cleva-
tion by Fig. 7, is fitted to the opening, so that it may be closed when
required. The bearing bars F, which support the fire bars, are also
made hollow, as shewn by the section, Fig. 8, and by the front view,
Fig. 9. By this arrangement a current of air traverses through them,
by which they are kept cool, and thus last much longer than if made of
solid metal. The bridge plate H is shewn in side elevation by Fig. 10.

page_text: A bridge formed of fire clay lumps rests upon the surface f; the ends of
the fire bars are supported by the angular part g; an opening h is made
in the lower part of the bridge plate opposite the apertures in the fire
bars. K is a door opening from the ash-pit, for the purpose of clearing
out the ashes behind the bridge. Upon the fires being lighted, the
damper e beneath the dead plate is closed for a short time, so as to
prevent the passage of air through the bars. When the fire has burned
clear the damper is opened, and the air passes through the openings in
the bars, becoming highly heated in its passage; upon emerging from
the end of the bars it passes round the bridge, and meeting the smoke
and unconsumed gases it ignites them, causing the heat arising from
the combustion to be imparted to the metal in contact with the water
in the boiler. A further supply of air is furnished by the tubes M,
which communicate with the external air by openings in the smoke box
doors L. This last supply of air causes the thorough ignition of any
portion of combustible gas that may remain in the furnace, and prevents
any visible smoke from passing off by the funnel.
By the foregoing arrangement, the supply of air to the furnace being
highly heated before it reaches the fuel, the furnace is maintained at a
much higher temperature than with the ordinary construction; conse-
quently, a smaller quantity of fuel will be consumed in heating a given
quantity of water. When it is required to damp the fires, the doors N
at the bottom of the smoke box doors are to be opened; a current of cold
air is admitted into the funnel, which instantly checks the draught, and
saves the furnace plates from unequal contraction, besides obviating the
usual unpleasant consequences in the engine room, resulting from open-
ing furnace doors or closing dampers. The application of these improve-
ments to stationary boilers is shown by Figs. 11, 12, and 13. Fig. 11 is
a longitudinal section of a furnace and boiler; Fig. 12 is a plan; and
Fig. 13, a transverse section of the same. O is the dead plate; P, the
fire bars; Q, the bearing bars; R, the bridge; S, door at the back of the
ash-pit; T, bridge in the combustion chamber; U, the flue leading to the
shaft V; W, the boiler. The air passes through the hollow bars P behind
the bridge R; here the heated air meets the unconsumed gases, which
are ignited, and pass along the under part of the boiler, and thence
round the flue U to the shaft V. By making the fire bars of malleable
iron, and keeping them comparatively cool by currents of air passing
through them, they will last much longer than the ordinary cast-iron

page_text: bars, and when useless as fire or bearing bars, the malleable metal is
then valuable as an article of commerce.
Having described the nature of my Invention, and the manner of
carrying the same into effect, I wish it to be understood that I do not
confine myself to the precise arrangement of the details as herein
described and shown, as the same may be varied more or less without
departing from the Invention; but what I claim, and desire to secure
by the herein-before in part recited Letters Patent, is, constructing
the furnaces of steam engines with hollow malleable iron fire bars, and
with air tubes for the admission of atmospheric air; also doors to check
the fire instead of opening the furnace doors; and the peculiar arrange-
ment of the bearing bars, dead and bridge plates, and ash-pit door, for
the purpose of consuming the smoke given off by the fuel, in-the manner
and for the purposes herein-before shown and described.
In witness whereof, I, the said William Burtt Wilton, have here-
unto set my hand and seal, the Eighteenth day of October, in the
year of our Lord One thousand eight hundred and fifty-five.
WILLIAM BURTT WILTON. (L's.)
Witness,
JAMES GRAHAM,
Engineer, Lowestoft.