IMPROVEMENTS IN FURNACES
Year: 1854

page_text: LETTERS PATENT to Charles Cowper, of 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, for the
Invention of "IMPROVEMENTS IN FURNACES."-A communication from
Léonard Laureau, of Paris, in France.
Sealed the 28th July 1854, and dated the 24th February 1854.
PROVISIONAL SPECIFICATION left by the said Charles Cowper at the
Office of the Commissioners of Patents, with his Petition, on the 24th
February 1854.
I, CHARLES COWPER, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN FURNACES" to be as follows:-
I construct a furnace somewhat resembling the blast furnaces employed in the
manufacture of iron, but of oblong form in the horizontal section, and provided
with double slides for closing the top of the furnace while admitting of the
introduction of the fuel or other materials. At the side of this furnace one, two,
or more fire grates are placed, and the products of combustion from these grates
enter the furnace near the bottom. These grates are double, and consist of a
lower grate of iron bars, and an upper grate formed of iron or clay tubes, through
which air enters the furnace. The fuel which falls through the upper grate
continues to burn on the lower grate, and the upper grate is thus kept at a
high temperature, so that the air which passes through the tubes becomes
heated before entering the furnace. When the furnace is employed for
melting iron, the slag or cinder may be allowed to flow away through a tube

page_text: or passage, which is kept hot by being placed between the two grates. Above
each of the grates is a retort, or series of retorts, the back ends of which are
perforated. These are to be charged with coal or other substance capable of
giving off a gas or vapour, when it is desired to introduce such gas or vapour
into the furnace. The top of the furnace is closed, as already mentioned, but
several rows of apertures are made in the side of the furnace for the escape of
the products of combustion. The gases or products which escape at the
upper apertures are conveyed into the stream of flame or hot products of com-
bustion escaping from the lower apertures, and the whole passes along a flue
or series of chambers, and thence into a chimney. A shower of water may
be allowed to fall through apertures in the tops of these chambers into pans
or cisterns, forming the bottoms of the chambers, so as to condense the smoke,
if any is produced, or to arrest any small particles of metal or other valuable
substances carried away by the stream of flame or products of combustion.
When the products of combustion are much reduced in temperature in this
manner, and a strong draft is still required, it may be effected by applying a
fire at the bottom of the chimney, or by a jet of steam, or by blowing air into
the furnace by a fan, or by other mechanical means. Short cones of fire clay
or other suitable material may be introduced into the air-passages and other
passages, to offer a resistance to the return of the air or products of com-
bustion, without preventing their passage in the required directions. Sight
holes are provided for examining the state of the furnace at different
parts.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Cowper in the Great Seal Patent Office on the
22nd August 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWPER, of 20, Southampton Buildings, Chancery Lane, in the County of
Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of February, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Cowper, Her special licence that I, the said Charles Cowper,
my executors, administrators, and assigns, or such others as I, the said Charles 3
Cowper, 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

page_text: 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,"
communicated to me by Léonard Laureau, of Paris, in France, upon the con-
dition (amongst others) that I, the said Charles Cowper, by an instrument in
writing under my 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 Charles Cowper, 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 thereof, reference being had to the accompanying Drawing, and to
the figures and letters marked thereon (that is to say):-
The Invention consists in a new system or systems of furnaces, constructed
in manner hereinafter described, and adapted for the smelting of iron, the
melting of glass and enamel, and a variety of other purposes. Figure 1 of
the accompanying Drawing is a vertical section of a furnace constructed
according to the Invention. Figure 2 is a horizontal section of the same on
the line 1, 2, in Figure 1. Figure 3 is a transverse vertical section of the same
on the line 3, 4, in Figure 1. The same letters indicate similar parts in each
Figure. The furnace shewn in these Figures is intended to be made about
eight feet in height, and is intended for smelting iron ores and other purposes.
The dimensions may, however, be greatly varied, but it may always be made
of much less height than the ordinary blast furnaces. A sufficient capacity is
obtained by increasing its width and the number of fires. The furnace shewn
in the Figures has only two fires C, which are separated by the pier B. These
fires are covered by a series of cylinders or retorts of iron or fire clay D, for
generating carburetted hydrogen or other gases which it may be required to
introduce into the furnace. The gases pass through perforations ; in the
backs of the retorts, and descending, pass under the brickwork or masonry k,
and enter the body of the furnace N. Each fire has two grates E and F,
placed one above the other. The upper grate consists of a series of tubes of
iron or fire clay E, supported on a frame b. Each of these tubes contains a
number of small hollow cones of iron or clay d, having all their apices directed
towards the interior of the furnace. These tubes E are always kept at a high
temperature by the fire resting upon them, and also by the cinders or par-
tially consumed fuel which drops between them on to the second grate F.

page_text: Air passes through these tubes, and becoming highly heated, meets with the
products of combustion of the fire and the gases from the retorts D, and the
intensely hot flame thus produced enters the body of the furnace N, between
the short pillars or supports 7, 1.
The second grate F is intended for burning the cinders or partially con-
sumed fuel, and the smaller portions of the fuel which fall between the tubes
of the upper grate.
The bars of the second grate are of iron, and placed closer together than
those of the upper grate. A triangular or prismatic tube c, with one of its
angles downwards, is placed between the two grates, and employed for con-
veying away the slag when the furnace is used for smelting iron. This tube
c being placed between the two grates, is kept sufficiently hot to prevent the
slag from solidifying in it. All the parts of the fire-places, including the
supports of the grates, are capable of being removed and replaced when
repairs become necessary. To facilitate this operation and to support the
upper part of the furnace, each fire-place is covered with a large block or
bearer of stone at G. When the central pier B requires repairs, these stone
bearers are supported by temporary props. One or more openings e are made
in the front of the furnace for introducing gases or other matters, if required,
and also for examining the interior of the furnace when required. These
openings are generally kept well closed. ff, are two sliding plates or registers,
which slide in frames built into the upper part or throat of the furnace;
these registers have apertures in them corresponding to a series of prismatic
or semi-circular pieces of stone or cast iron H fixed in the throat of the
furnace, so that by drawing the registers out a little, their apertures are brought
under the spaces between the pieces II, and anything placed there is allowed
to fall through. The charge of materials is thus introduced into the furnace,
and by closing one register before the other is opened, the products of com-
bustion are prevented from escaping, and the air is also prevented from enter-
ing. is another plate without apertures, which serves for covering the top of
the furnace. If it be required to close the top of the furnace still more effec-
tually, the plate g is made with a rim round its edge, which enters a groove
containing water or other liquid, so as to make an hydraulic joint. The walls
of the upper part of the furnace are made thinner than at the lower part, so
as to prevent the upper part from becoming too hot.
The capacity of the furnace may be greatly increased by lengthening it and
increasing the number of fires, without the necessity of increasing its height,
and the heat of each part of the furnace may be regulated by urging or
slackening the different fires. i is the crucible from which the melted iron or

page_text: other substance is drawn off from time to time at P. M is the brickwork
or masonry forming the back of the furnace, and having several passages
I, I, I, and K, communicating with the common passage J. The vapours and
gases in the upper part of the furnace escape by the passages I, I, I, and join
the torrent of flame passing through the passages K. The united stream
passes through the channels L into the condensing flue Q, and thence up the
chimney O. The flue Q is constructed of stone or granite, and may be from
fifteen to thirty feet long, or more or less; its bottom is formed of basins of
granite, each of which is furnished with an outlet passage and stopper. The top
of the condensing flue is formed of flat stones or flags R, pierced with holes and
with grooves or gutters formed in their surfaces; these flags are covered with
sand, which is constantly supplied with water, so as to produce a continual
shower in the condensing flue Q. The condensible matters carried away by
the flame and products of combustion are thus condensed in the flue Q, in lieu
of passing up the chimney. A furnace or fire-place may be placed at the
bottom of the chimney O to increase the draught. The flue is made with
alternate enlargements and contractions of section to check the return of the
gases towards the furnace. Figure 4 is a vertical section of another furnace
constructed according to the Invention; Figure 5 is a transverse section of
the same.
This furnace is in many respects similar to that first herein-
before described, but it is furnished with a fire or series of fires on both sides,
and the products of combustion are conveyed away from the top of the
furnace. The body of the furnace N¹ is formed of a double envelope of iron
plate n and n, of which the inner part n is made of very strong plates, and
the outer part n' of thinner plates. The ends are also formed by thick
plates m, and thinner plates m³, and the whole is firmly rivetted together.
The spaces between the plates are filled with quick lime well rammed in.
The envelope m is supported by the iron bars 0, 0, and by the bolts or tie
rods P. The end plates m¹ are prolonged and rivetted to the horizontal
plates, and the space l, being enclosed by an cuter casing, may also be
filled with quick lime. Under the plates k³ are the retorts D', made of wrought
iron, and intended (like those in the furnace first herein-before described) to
introduce into the stream of the products of combustion vapours or gases,
such as carburetted hydrogen, or ammonia, or such other vapours or gases as
it may be required to introduce. These retorts are supported by long bolts q
and upright supports q. Below the retorts D' is the fire-place C, having two
grates, as before. The upper grate is formed of the tubes E', supported upon
a cast iron frame. Revolving screws d' are mounted inside the tubes E¹ to
produce a current of hot air, which enters at the back of the fire-place.

page_text: The lower grate F¹ is formed of iron bars, as in the furnace first herein-before
described.
A similar fire-place is placed on the opposite side of the furnace, and
between them is a mass of brickwork covered with plate iron, which supports
the hearths or crucibles i, ¹, which serve to receive the melted iron when the
furnace is employed for smelting iron ores. r, r', are channels for conveying
away the slag or cinder. The furnace is provided with a cover g, and two
sliding registers f and f³ in its upper part or throat, so as to admit of
charging it without opening the top. The semi-cylindrical transverse pieces H
(which correspond to those marked H in Figure 3,) are in this case made
hollow, and perforated with holes on their lower surfaces, and they serve for the
exit of the gases and products of combustion from the furnace. They are con-
nected by the tubes H2, H3, to a set of hydraulic bellows or exhausters, by
which the gases are drawn or forced through water which absorbs the soluble
matters. The exhausters are hollow vessels inverted in water, like gasometers,
and working up and down or turning on a hinge at one side, and furnished
with suitable hydraulic or other valves. By this means, the matters carried away
by the products of combustion are condensed, and injurious exhalations may
thus be prevented. The capacity of this furnace may be increased like that
first herein-before described, without the necessity of increasing its height.
The temperature at any part may be regulated by varying the draught at that
part, which is easily done by means of valves or registers in the tubes H2, H3,
or by varying the speed of the exhausters.
Having now described the nature of the said Invention as communicated
to me, and the manner in which the same is to be performed, I wish it
to be understood, that what I claim is, the mode or modes of constructing
furnaces, as herein-before described.
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this Twenty-second day of August, in the year of our
Lord One thousand eight hundred and fifty-four.
Witness,
THOS. TAYLOR, jn',
7, Wellington Row,
Bethnal Green.
CHARLES COWPER. (L.S.)