IMPROVEMENTS IN THE CON- STRUCTION OF THE FURNACES OF BAKERS' OVENS, FOR THE PURPOSE OF CONSUMING SMOKE, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO THE CON- SUMPTION OF SMOKE IN OTHER FURNACES
Year: 1859

page_text: LETTERS PATENT to James Anderson and James Bradshaw, Bakers,
Liverpool, Lancashire, for the Invention of "IMPROVEMENTS IN THE CON-
STRUCTION OF THE FURNACES OF BAKERS' OVENS, FOR THE PURPOSE OF
CONSUMING SMOKE, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO THE CON-
SUMPTION OF SMOKE IN OTHER FURNACES."
COMPLETE SPECIFICATION filed by the said James Anderson and James
Bradshaw at the Office of the Commissioners of Patents, with their
Petition and Declaration, on the 3rd December 1859, pursuant to the
9th Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
ANDERSON and JAMES BRADSHAW, Bakers, of Liverpool, Lancashire, send
greeting.
WHEREAS we are in possession of an Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF THE FURNACES OF BAKERS' OVENS, FOR THE PURPOSE OF CONSUMING
SMOKE, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO THE CONSUMPTION OF SMOKE
IN OTHER FURNACES," and have petitioned Her Majesty to grant unto us, our

page_text: executors, administrators, and assigns, Her Royal Letters Patent for the
same, and have made solemn declaration that we verily believe ourselves to
be the true and first Inventors thereof.
NOW KNOW YE, that we, the said James Anderson and James Bradshaw,
do hereby declare that the following Complete Specification under our hands
and seals fully describes and ascertains the nature of the said Invention, and
the manner in which the same is to be performed, reference being had to
the accompanying Drawings, that is to say :-
Our Invention relates to a novel combination of the parts of furnaces, and is
principally designed for the purpose of consuming the smoke in bakers' ovens,
but with slight modifications is also applicable to like purposes in other
furnaces. By its adoption the fuel is economised in such furnaces, and a
better combustion is effected of the gaseous matters evolved from the fuel,
thereby preventing the discharge of smoke.
Hitherto it has been customary in the arrangement of flues for the com-
bustion of smoke in bakers' ovens and other furnaces to admit the atmospheric
air directly into the furnace itself, the tendency of which is to considerably
reduce the temperature of the furnace, thereby destroying to a great extent
the full advantageous effect of the fuel for heating the oven or furnace.
One arrangement of our Invention consists in the following combination of
parts: We provide an additional flue, which is carried into the main flue of
the oven or furnace; in this additional flue we insert a damper for the purpose
of regulating the supply of air to the main flue; the air flue thus terminating
in the chimney, the oven or boiler receives the full benefit of the heat from
the incandescent fuel without any loss of temperature arising from the intro-
duction of cold air into the oven or furnace. Dampers are provided in the
furnace flue to regulate the strength of the draught. The mode of operating
the dampers is as follows:-When the furnace damper is open fully, the smoke
arising from the furnace will be the same as that arising from an ordinary
furnace or chimney; this damper requires to be fully open for about ten or
fifteen minutes, until the flame bursts completely through the coals; that is, when
the coals are first placed upon the grate. In the additional air flue, near to the
point where it joins the furnace flue, we insert a damper for the purpose of
regulating the air draught; the air draught must be regulated by the strength
of the furnace draught; this can be effected by means of the dampers placed in
the air flues and furnace flues. In one instance where we have employed this
arrangement the furnace flue is 9 inches square, and the air flue is 9 inches
by 12 inches; this proportion is found to work well, the height of the chimney

page_text: being 50 feet.
Where there are two furnaces, and the flues are connected in
one chimney, there must be an air-draught flue for each furnace, with suitable
dampers for regulating the supply of atmospheric air to the furnaces. By this
means a great saving is effected in the consumption of fuel, the combustion of
the same being more perfect; and by keeping thin fires and firing frequently
and carefully, any quantity of steam can be kept up in the boiler or heat in
the oven, as the case may be.
In another arrangement we employ a series of perforated plates inserted in
the main flue or chimney; the first of these plates is placed upon. the top of
the oven or furnace immediately at the root of the main flue or chimney, a
second at any suitable distance above the first, and the third at any suitable
distance above the second; a greater or lesser number of these plates may be
used, as we do not confine ourselves to number. Above the perforated plates
a perforated box is placed in the flue or chimney, provided with a sliding
damper, for the purpose of regulating the air draught, and supplying atmos-
pheric air for combustion of the gaseous elements of the fuel.
In order that our said Invention may be thoroughly and completely com-
prehended, we proceed to describe the illustrative Figures upon the explanatory
Sheet of Drawings, which we have hereunto appended for the purpose of
shewing certain modifications under which our said improvements may be
judiciously and effectively carried into practice.
Figure 1 of the Drawings accompanying this Specification illustrates one
modification of our improvements connected with bakers' ovens, for regulating
the supply of air for the purposes of combustion.
Figure 2 of the Drawings accompanying this Specification illustrates
another modification of our improvements as applied to steam boiler furnaces
for the efficient combustion of smoke.
Figure 1 is an elevation of an oven used for baking bread, usually termed a
baker's oven, and having our improvements applied thereunto; it is shewn in
perspective, and represents a transverse vertical section, in order more clearly
to shew the internal arrangements.
Figure 2 is an end elevation of a steam boiler furnace illustrating our
improvements as applied thereunto; it is shewn in transverse vertical section.
Referring to the arrangement shewn in Figure 1, A is the oven or furnace
mouth; G, the flue or chimney; B is the first perforated iron plate, placed
upon the upper part of the furnace or oven, immediately across the inlet to
the flue or chimney through which the flame and incombustible products pass
on their passage into the flue; C is the second perforated plate, built into the

page_text: side walls of the flue or chimney extending completely across the outlet ; D is
the third perforated plate, built into the side walls of the flue or chimney, and
extending completely across the outlet; E is a rectangular box or casing, set
into the brickwork of the flue or chimney, (and forming the inlet for the
atmospheric air into the chimney or flue; F is the damper, which slides in the
rectangular air box or casing E, and is used for regulating the draught in
the flue or chimney, likewise for the purpose of regulating the admission of
air into the flue or chimney. Although we have shewn the oven, Figure 1,
with the perforated plates and rectangular air box, with sliding dampers
placed in the flue or chimney, we do not confine ourselves to this arrangement,
as the additional air flue may be used, as shewn in Figure 2, separately or
combined with the perforated plates and rectangular air box with sliding
damper.
Referring to the arrangements shewn in Figure 2, A is the boiler; B, B,
interior of furnaces; C, the chimney; D, additional air flue, passing into the
chimney; E is the damper for regulating the admission of the atmospheric
air into the chimney through the air-draught flue; F, F, are the boiler flues;
G, G, the dampers in the main flue or chimney for the purpose of regulating
the draught.
Although we have shewn the boiler furnace with the additional air flue on
the Drawing, Figure 2, we do not confines ourselves to this arrangement, as the
same combination of perforated plates and rectangular air box with sliding
damper may be used in the main flue or chimney, as represented in Figure 1,
separately or combined with the additional air flue.
Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is or may be used or carried
into effect, we may observe, in conclusion, that we do not bind or restrict
ourselves to the precise details of each arrangement which we have had
occasion to describe or refer to, as many variations may be made therefrom
without deviating from the principles or main features of our Invention; but
that which we consider to be novel and original, and therefore claim as our
Invention,-
First, the general arrangement and mode of supplying furnaces with air, in
order to insure the complete combustion of the gaseous elements, and prevent
the emission of smoke, as herein-before described.
Secondly, the system or mode of admitting and controlling the passage of
air into furnaces, the quantity of air admitted being regulated as the smoke is
evolved from the burning fuel; this effect being produced by the means and

page_text: combinations of arrangements herein-before described, or any mere equivalent
herefore.
In witness whereof, we, the said James Anderson and James Bradshaw,
have hereunto set our hands and seals, this Sixteenth day of November,
in the year of our Lord One thousand eight hundred and fifty-nine.
JAMES ANDERSON.
(L.S.)
Witness,
M. HUNTER, Patent Agent,
131, Fleet Street.
JAMES BRADSHAW. (L.S.)