IMPROVEMENTS IN FURNACES
Year: 1861

page_text: LETTERS PATENT to John Watson, of Glasgow, in the County of Lanark,
North Britain, Engineer, for the Invention of "IMPROVEMENTS IN
FURNACES."
Sealed the 25th February 1862, and dated the 2nd September 1861.
PROVISIONAL SPECIFICATION left by the said John Watson at the
Office of the Commissioners of Patents, with his Petition, on the 2nd
September 1861.
I, JOHN WATSON, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention of "IMPROVE-
MENTS IN FURNACES," to be as follows, that is to say:-
This Invention relates to the arrangement and construction of furnaces
suitable for heating boilers and other generally similar purposes.
Under one modification or arrangement of the improved furnace the furnace
bars are formed of a serrated figure, that is to say, they are cast or otherwise
formed with laterally projecting teeth of a rectangular figure. These bars
are arranged across the furnace in a direction at right angles to the length
of the furnace, and they rest at each end upon a longitudinal pipe or air
passage, which extends from the front to the back part of the furnace.
These air passages are made with lateral projections on their external surface,
which alternately come in contact with the bars, and a rotatory or partially
When these
rotatory motion is communicated to the tubular air passages.
air tubes are put in motion each alternate bar is raised, which has the effect
of breaking up the clinkers as well as of exposing the fuel in a very superior
manner to the action of the draft from the teeth of one bar projecting into
Price 8d.1

page_text: the recesses of the contiguous bar. At the end of the range of fire-bars
is a perforated fire bridge, and beyond this in a backward direction is a
second fire bridge built up solid and parallel to the first. The opening al
the upper part between the duplex fire-bridges is closed by means of slabs
of fire-clay or other suitable material. The air passages extending beneath
the fire-bars open into the chamber formed between the fire bridges, and in
its passage thereto gets considerably heated. The air thus passed into the
chamber issues out through the horizontal openings in the front fire bridge,
where it comes into contact with the uniguited gaseous matters evolved from
the burning fuel, which are thus instantly flashed into flame and the emission
of visible smoke is thus prevented. In this way the bars may be made
much lighter, the fuel is more effectually and economically consumed, the
stoppage of the draft from the accumulation of clinker is entirely prevented,
and at the same time the visible smoke is consumed by the peculiar arrange-
ment of the air passages and the chamber formed between the duplex
fire bridges.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Watson in the Great Seal Patent Office on the 1st
March 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WATSON, of Glasgow, in the County of Lanark, North Britain, Engineer,
send greeting.
WHEREAS er most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of September, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Watson, her special license that 1, the said John Watson, my
executors, administrators, and assigns, or such others as I, the said John
Watson, my executors, administrators, or assigns, should at any time agreo
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
FURNACES," upon the condition (amongst others) that I, the said John
Watson, my executors or administrators, by an instrument in writing under
my hand and seal, or under the hand and seal of one of them, should parti-

page_text: cularly 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 Watson, 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, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
My said Invention relates to the arrangement and construction of furnaces
suitable for heating boilers and other generally similar purposes.
Under one modification or arrangement of the improved furnace the
furnace bars are formed of a serrated figure, that is to say, they are cast or
otherwise formed with laterally projecting teeth of a rectangular figure.
These bars are arranged across the furnace in a direction at right angles
to the length of the furnace, and they rest at each end upon a longitudinal
pipe or air passage which extends from the front to the back part of the
furnace. These air passages are made with lateral projections on the
external surface which alternately come in contact with the bars, and a
rotatory or partially rotatory motion is communicated to the tubular air
passages. When these air tubes are put in motion each alternate bar is
raised, which has the effect of breaking up the clinkers as well as of exposing
the fuel in a very superior manner to the action of the draft from the teeth
of one bar projecting into the recesses of the contiguous bar. At the end
of the range of fire-bars is a perforated fire bridge, and beyond this in a
backward direction is a second fire bridge built up solid and parallel to the
first. The opening at the upper part between the duplex fire bridges
is closed by means of slabs of fire-clay or other suitable material. The air
passages extending beneath the fire-bars open into the chamber formed
between the fire bridges, and in its passage thereto gets considerably heated.
The air thus passed into the chamber issues out through the horizontal
openings in the front fire bridge, where it comes in contact with the unignited
gaseous matters evolved from the burning fuel, which are thus instantly
flashed into flame, and the emission of visible smoke is thus prevented.
this way the bars may be made much lighter, the fuel is more effectually
and economically consumed, the stoppage of the draft from the accumulation
of clinker is entirely prevented, and at the same time the visible smoke is
consumed by the peculiar arrangement of the air passages and the chamber
formed between the duplex fire bridges.
In

page_text: And in order that my said Invention of improvements in furnaces may be
properly understood. I shall now proceed to describe the several Figures on
the accompanying Sheet of illustrative Drawings, for the purpose of showing
certain modifications under which my improvements may be judiciously carried
out in practice, that is to say: -
Figure 1 of the accompanying Drawings is a half end elevation and half
vertical section of one arrangement of my improved furnaces as applied to
the heating of steam engine boilers; Figure 2 is a partial longitudinal section
of the same, and Figure 3 is a plan corresponding to Figure 1.
Figure 4 is an elevation showing another modification in the arrangement
of the details of the furnace bars; Figure 5 is a transverse section taken at
right angles to Figure 4, and Figure 6 is a plan corresponding to Figures 4
and 5.
The brickwork A of the furnace is arranged in the ordinary way, the dead
plate and furnace mouth B is of the usual kind. Extending beneath this
on each side of the ash-pit C is a tubular air passage D. which is supported
at the front end by a curved pendent bracket E, or in any other convenient
way. If found preferable the front part of the air passages may be supported
on the inner side by a semicircular pendent bracket cast on the under side
of the dead plate and outside by a corresponding moveable support bolted
up to the dead plate as shown in the Drawings. The backward end of each
air passage D passes through and rests in the fire bridge F, which forms
the backward extremity of the ash-pit C. On the inner portions of the
peripheries of the air tubes D are cast the laterally projecting teeth G, which
act as cams to raise each alternate fire-bar when the air tube is turned
partially round. The fire-bars are cast with laterally projecting teeth or
serrations, the end teeth and one in the centre being made a little longer
than the others, so that when arranged on the air tubes D the bars are
placed close together; these teeth serving to give steadiness to the bars,
and at the same time leave a suflicient space between the intervening teeth
as shown in the plan view, Figure 3. The bars are hollowed on the under
side so as to rest fairly on the upper part of the air tubes D, and they are
arranged across the furnace at right angles to its length. Each tooth of one
bar enters the corresponding recess of the contiguous bar, but the elongated
teeth at the ends and centres are the only ones which touch the neighbouring
bar. The inner end of the dead plate D is serrated to correspond with the
first bar, the other bars are slipped into their places and arranged parallel,
filling up the longitudinal extent of the furnace to the serrated plate I, which
forms a facing to the fire-bridge F. The teeth G on the air tubes D are

page_text: formed with recesses at the central part of each, and these are arranged at
such a distance asunder that the lower part of each bar falls into one of these
recesses on the one side and at the other into the space J, between the teeth G,
each tooth G being opposite a space J.
It follows from this arrangement
that if the air tubes D are turned partly round each alternate bar will be
raised up at the end on that side of the furnace on which the air tube is
actuated. This motion of the alternate bars arises from the cam-like form
given to the central part of each of the teeth G, the inclined plane of the
central part serving to lift the bars which rest thereon, whilst the intermediate
bars are unaffected because they rest simply on the cylindrical surface of
the air tube. The front ends of the air tubes D project out beyond the
brickwork A, and holes K are formed in the rim to admit of a bar or
hand lever being inserted therein. When the furnace working, the stoker
from time to time moves the hand levers to and fro alternately, which
raises up the fire-bars H, breaks up the fuel, allows the ash to fall through,
and prevents the formation of clinkers. The raising of the bars from time
to time has also the effect of causing a large body of air to pass into the
fuel, and it is thus kept in a state of intense combustion. The arrangement of
the furnace also provides for the effectual combustion of the inflammable
portion of the gaseous matters evolved, and thus prevent the emission of
visible smoke from the chimney. The tubes D convey a considerable body
of air into the chamber formed between the fire-bridge F and the secondary
bridge L built parallel to the first. The upper part of this air chamber has
three or other number of the serrated bars M arranged at the top of the
fire-bridges, which serve to divide the air and cause it to issue in streams
which meet the smoke and ignite the combustible portion of the gascous
matters. In the centre of the plate is a third tubular aperture N to admit
if required a further portion of air, the admission of which is controlled by
the throttle valve o, regulated by a rod extending to the front of the
ash-pit or in any other convenient way. In wide furnaces the weight of the
fire-bars and of the fuel resting thereon is sufficient to cause them to descend
on to their bearings after being raised by turning the tube D. But in
furnaces of the narrower kind mechanical means are provided for preventing
any of the bars remaining uplifted; this arrangement is delineated in
Figures 4, 5, and 6, of the accompanying Drawings. In this modification
each bar is made with a snug P cast on its under side and projecting in
an angular direction towards the teeth G on the contiguous air tube D.
One half of the bars in the furnace are cast with the snugs at one extremity
and one half with them at the other, and when arranged in the furnace

page_text: they are placed with the snugs right and left, as shown in Figures 4 and 5.
Thus when either of the air tubes D is turned partly round one-half of the
bars are raised by the teeth G, and as the tube is turned back to its normal
position the lateral portion of each tooth G catches on the contiguous
snug P. as shown in Figure 4, and ensures the due descent of the bar.
Although I have described these air tubes as having only a partially rotatory
movement and delineated them in a corresponding manner in the accom-
panying Drawings, I do not by any means confine myself to this particular
arrangement; for it is obvious that the tubes or air passages may be
arranged for a complete rotatory movement and motion may be imparted to
either modification by steam power if preferred.
Having now described and particularly ascertained the nature of my 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 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 arrangement, construction, and combination of parts.
forming the improved furnaces ns herein-before described and shown in the
accompanying Drawings.
Second, the system or mode of arranging and constructing furnaces with
transverse serrated bars, to which a vertical or other equivalent movement is
imparted by the mechanical means herein-before described and shown in the
accompanying Drawings or any mere modification of the same.
Third, the system or mode of arranging and constructing the air passages
and air chambers of furnaces for ensuring the admission of a duc supply of
air to the back part of the furnace so as to ignite thoroughly the inflammable
portion of the gascous matters evolved and so prevent the emission of visible
smoke, as herein-before described and shown in the accompanying Drawings,
or any mere equivalent for the said arrangement.
In witness whereof, I, the said John Watson, have hereunto set my
hand and seal, this Twenty-seventh day of February, One thousand
eight hundred and sixty-two.
JOHN WATSON. (L.S.)