IMPROVEMENTS IN FURNACES
Year: 1866

page_text: LETTERS PATENT to Thomas Prideaux, of Sheffield, in the County of
York, Hotel-keeper, for the Invention of "IMPROVEMENTS IN FURNACES."
Sealed the 17th April 1866, and dated the 1st January 1866.
PROVISIONAL SPECIFICATION left by the said Thomas Prideaux at
the Office of the Commissioners of Patents, with his Petition, on
the 1st January 1866.
I, THOMAS PRIDEAUX, of. Sheffield, in the County of York, Hotel-keeper,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN,
FURNACES," to be as follows:-
The object of this Invention is to construct furnaces in such manner that.
they will heat more expeditiously and consume their own smoke more
effectually than those hitherto used or known. The construction of a furnace.
which should effectually consume its own smoke has been attended. with
such difficulty that none of the contrivances heretofore produced have:
effectually accomplished that object..
Now according to my Invention the whole of the front of the furnace, is
built up or fitted with air-tight doors, as well as the front of the ash-pit, no
air being allowed to pass into the. furnace. at. those parts thereof, and the fire,

page_text: is supplied with the amount of air necessary to maintain combustion through
tubes or channels which communicate with the furnace on opposite sides
thereof, and are laid horizontally along the sides of the boiler or furnace,
and carried upwards at the back thereof or in some other convenient situa-
tion, the outer ends of these tubes or channels being open to the air, a
supply of which thus passes down and along these tubes or channels and
enters the fire-place above the grate bars, the currents of air from these tubes
or channels thus entering on opposite sides of the fire, and by their combined
-effect maintaining the combustion of the fuel employed, as well as of the
smoke generated by such combustion. The tubes or channels may be so
arranged with reference to the other parts of the furnace that the air passing
through them may be heated before it reaches the fire, and the passage of
air along such tubes or channels may be facilitated by the
fans if found desirable.
use of a fan or
The Invention is applicable to furnaces of all kinds, including those.
employed in the treatment of metals and other substances.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas. Prideaux in the Great Seal Patent Office on the
29th June 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
PRIDEAUX, of Sheffield, in the County of York, Hotel-keeper, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters-
Patent, bearing date the First day of January, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign; did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Prideaux, Her special licence that I, the said Thomas
Prideaux, my executors, administrators, and assigns, or such others as I,
the said Thomas Prideaux, my executors, administrators, and assigns, should
at any tinie 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 "IMPROVE-
MENTS IN FURNACES," upon the condition (amongst others) that I, the said,
Thomas Prideaux, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and

page_text: 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 Thomas Prideaux, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement and accompanying Drawing (that is to say):
-
In the construction of furnaces it is highly desirable that the arrangements
should be such as not only to ensure rapid and complete ignition and combus-
tion of the fuel employed, but also consumption of the smoke generated by
such combustion. Heretofore the construction of a furnace which should
effectually consume its own smoke has been attended with such difficulty that
none of the contrivances hitherto adopted have effectually, accomplished that
object.
Now according to my Invention the whole of the front of the furnance is
closed by being built up or furnished with air-tight doors, as well as the front
of the ash-pit (should an ash-pit exist or be thought desirable), no air being
allowed to pass into the furnace at those parts thereof, and the fire is supplied
with the necessary amount of air to maintain combustion through tubes or
channels which communicate with the fire-place on opposite sides thereof, and
are then laid horizontally along the sides of the furnace (or boiler if the
furnace be applied to a boiler), and carried upwards at the back thereof or
in some other convenient situation, the outer ends of these tubes or channels
being open to the air, a supply of which thus passes down and along these tubes
or channels and enters the fire-place above the grate bars, or whatever the
fuel may rest upon, at such points as may seem most convenient, the currents.
of air from these tubes or channels thus entering on opposite sides of the
furnace, and by their combined effect maintaining the combustion of the fuel
employed as well as of the smoke generated by such combustion. The tubes.
or channels may be so arranged with reference to the other parts of tho.
furnace that the air passing through them may be heated before it reaches,
the fire, and the passage of the air along such tubes or channels may be.
facilitated by the use of a fan or fans if found desirable.
In order to illustrate the manner in which my Invention may be put in
practice, I bave hereunto annexed a Sheet of Drawings, by reference to which
the Invention will be more clearly understood.
Figure represents the ground plan of a furnace, showing one mode in
which the air passages may be arranged. Let A be the furnace, B the bridge,
and C the space under the boiler (for example) along which the heated

page_text: products of combustion pass in their way to proceed round the boiler or
otherwise to the chimney H. The front of the furnance (D) is entirely closed
up, and all access of air to the fire in that part prevented, and the supply of
hir for maintaining combustion is derived from the two passages or channels
E, E, which are open to the atmosphere at G, G, where they are turned
upwards, and where they receive a supply of air which passes along them
and enters the furnace at F, F. These passages E, E, may consist of tubes
laid in the brickwork of the furnace or boiler, or of passages formed in such
brickwork, and arranged as most convenient with reference to the flues which
surround the boiler, and the openings F, F, may be arranged as may seem
best suited to the particular construction of furnace and the amount of air-
required, and may vary in number and size accordingly; perforated bricks
may be used in the construction of these air passages.
.:
It is obvious that these arrangements may be variously modified, and I
wish to be distinctly understood as not confining myself to the precise arrange-
ment shown in Figure 1, or to any other particular arrangement, so long as
the essential features of my Invention are retained. For example, in the case
of a round boiler having two flues therein, the arrangement is necessarily
somewhat different as illustrated by Figure 2, which represents a sectional
elevation of the parts in front of such a boiler, Figure 3 being a longitudinal
elevation illustrative of the same arrangement. Here an air passage A is
formed in the brickwork on each side of the boiler, and inclines downwards
on arriving at the front end thereof, so as to join a part of the flue next to it
which projects beyond the boiler, as shown at B, Figure 3. The fires in the
flues are thus supplied with air, which enters, as denoted by the arrows, after
being heated by contact with the hot boiler, and in this case, as I find it would
be inconvenient to have an air passage on both sides of each fire, I make the
passages A of such dimensions that one of such passages furnishes a sufficient
supply of air for one fire, which arrangement I find to answer sufficiently
well in such cases. In such arrangements as this the fires may be supplied
with fuel by air-tight doors at the front ends of the flues, through which
a considerable quantity of fuel may be introduced into the fire-places at one
time, thus obviating the necessity of frequently opening the doors.
As I have already mentioned, the passage of air along the tubes or channels
through which it proceeds to the fire-place may be facilitated by the use of a
fan or fans if found desirable, and the air may be heated or not, as most
requisite, before entering the furnace.
Having now described the nature of my Invention, and the manner of
performing the same, I hereby declare that I claim as of my Invention the

page_text: construction of a furnace such as herein-before set forth, or any mere modifi-
cation of the same.
In witness whereof, I, the said Thomas Prideaux, have hereunto set my
band and seal, this Twenty-fifth day of June, One thousand eight
hundred and sixty-six.
Witness,
HENRY BRIERLY, C.E.,
27, Southampton Buildings,
Chancery Lane,
London.
THOMAS (L.S.) PRIDEAUX.