AN IMPROVEMENT IN THE CONSTRUCTION OF COKE
Year: 1853

page_text: LETTERS PATENT to Joseph Dunning, of No. 14, Regent Street, in
the Parish of St. James, in the City of Westminster, Architect,
for the Invention of "AN IMPROVEMENT IN THE CONSTRUCTION OF COKE
COMPLETE SPECIFICATION filed by the said Joseph Dunning at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 16th April 1853, pursuant to the 9th section
of the Patent Law Amendment Act 1852.
:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
Joseph Dunning, of No. 14, Regent Street, in the Parish of Saint
James, in the City of Westminster, Architect, send greeting.
NOW KNOW YE, that I, the said Joseph Dunning, do hereby
declare the nature of my said Invention, for "AN IMPROVEMENT IN THE
CONSTRUCTION OF COKE OVENS," 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 sheet of drawings
hereunto annexed and herein-after referred to); that is to say, in the

page_text: coking of coal, the object to be obtained is the combustion or dissipation of
the volatile principles of the coal with as little loss as possible of carbon;
and this is to be effected by subjecting the coal equally throughout the
mass to be coked to the operation of heat, with the least possible
supply of atmospheric air necessary for supporting the combustion
creating the heat.
But inasmuch as, in the coke ovens hitherto constructed, the heat is
very unequally applied to the mass of coal to be coked, in order to
obtain sufficient heat to pênetrate into, and to coke the inner and lower
portions of the charge of coal, it has hitherto been necessary to admit
such a quantity of air to, and to excite such an excessive combustion of
the upper portion of the coal, that great waste and loss of carbon
ensues; the coke produced is of very different qualities, according to
its position in the mass; and even when the process is conducted with
the greatest care, there generally remains a stratum of coal not coked,
of two inches or more in depth, next to and upon the floor of the oven.
Furthermore, owing to this difficulty of applying the heat equally, the
charge of coal to be converted into coke is necessarily limited, so that
not more than eight or nine tons of coal can be satisfactorily, and
without very great waste, coked at one operation; and this renders the
process of coking more expensive, from the greater cost of several small
ovens, and the greater expenditure of labour in working them, than
would be the case if ovens of larger capacity and more efficient in
operation could be used.
Now, the objects of my Invention are to construct coke ovens in such
a manner, that by economising the heat, and causing it to be applied
more equally to the charge of coal to be coked, they shall satisfactorily
and economically coke larger charges of coal, and produce in a shorter
time a larger quantity of coke from any given charge of coal, and of
better and more equal quality throughout the whole mass, than has
hitherto been effected.
I attain my objects by constructing my improved coke oven of the
materials, relative proportions, and general form (except as herein-after
otherwise specified), of the elliptical shaped coke ovens at present in use,.
but of such dimensions and capacity as that it will contain a charge,

page_text: not rising higher than the springing of the arch of the roof of the oven,
of from twenty to thirty tons of coal; that is to say, for the purpose of
coking a charge of about thirty tons of coal, I construct the oven, of
the shape and dimensions respectively shewn in the sheet of drawings
hereunto annexed, in which the interior of the oven (see Fig. 5,) is
twenty-four feet in length and fifteen feet in breadth, measured on the
floor of the oven, three feet six inches high from the floor (see Fig. 1,)
to the springing of the arch of the roof, and nine feet from the floor to
the crown of the 'arch (see Fig. 1); and for the purpose of facilitating
the process of coking, and the subsequent drawing of the coke from the
oven, I also make two doorways and doors, of the usual materials and
suitable dimensions, one at each end of the oven, as shewn at A, A, in
Figs. 5, and 6.
Instead of allowing the heat arising from the ignited coal in the oven
during the process of coking to pass away at the top or back of the
oven, through a flue leading directly into a chimney, I cause it to
circulate under the floor, and along a part of the sides of the oven, by
means of two vertical flues, one at each corner, at one end of the oven,
having their upper orifices in the interior of the oven, a little above the
springing of the arch of the roof, as shewn at B, Fig. 3. These two
vertical flues, of about fourteen inches square, sectional measure, are to
be carried down in the substance of the side of the oven, and close to
the usual fire-brick lining of the oven, as shewn at B, Fig. 3, and B, B,
Fig. 5, and made to open (see B, B, Fig. 4,) into, and to communicate
with a series of horizontal flues under the floor of the oven (see the
annexed slieet of drawings, in which Fig. 4, is a plan of the series of
horizontal parallel flues running lengthwise under the floor of the oven;
connected, and communicating with each other by means of two
horizontal curved. cross flues of similar size). These horizontal flues
are to be made in the substance of the floor of the oven, about nine
inches wide. and eighteen inches deep, the parallel straight flues being
separated from each other by walls about nine inches wide (as shewn in
section in Fig. 1, in which a, . . . a, is a section of the flues, and
b,.. b, a section of the walls); and the whole series of horizontal
flues is to be constructed at such a depth below the upper surface of the

page_text: floor of the oven, as to make the floor above these flues about six inches
in thickness. I also construct in the substance of the two longer sides
of the oven, close to the firebrick lining of the oven, two horizontal flues,
that is to say, one in each of the said longer sides of the oven, fourteen
inches deep and four inches wide, at such a level that their bottoms
may be about two inches above the level of the floor of the oven,
opening into and extending from the two vertical flues (B, B, Fig. 5),
to about two feet from the two chimnies herein-after described, in the
manner shewn by the dotted lines from C, to D, in Figure 5, and
connected at their ends D, with the horizontal flues under the floor of
the oven by descending flues of the same sectional dimensions, in the
manner shewn in section at C, C, Fig. 3, in which C, represents a
section of one of these horizontal flues, and the dotted lines from C, to
C, a section of the descending flue connecting this horizontal flue with
the series of horizontal flues under the floor of the oven. At that end
of the oven which is opposite to the two vertical flues above mentioned,
I construct in the substance of the side of the oven, two straight vertical
chimnies of about fourteen inches by nine inches, inside measure,
communicating with and opening at their base into the above described
horizontal flues under the floor of the oven, in the position and manner
shewn at F, F, in Figs. 4, and 5, and rising to any convenient height
above the exterior of the roof of the oven, as shewn at F, F, Fig. 2.
All these various flues, and the chimnies above described, are to be
constructed with the bricks and materials ordinarily used for the flues
and chimnies of coke ovens.
The oven, as thus constructed, may be charged with coal in the usual
manner; but I recommend that the coal should be introduced through
an opening at the top of the oven as shewn at E, in Figs. 1, 6, and 7;
and for the more easy spreading of a large charge of coal evenly over
the floor, I also recommend the use of a hopper, having below it an
inclined board, of length and width suited to the size of the oven,
moving at one end on an axis C, Fig. 7, placed at right angles to a
line drawn from door to door of the oven, so that by means of chains
attached to each side of the board, and by pulleys suitably fixed at the
bottom of the hopper, as shewn in Fig. 7, the coals may be projected

page_text: on to the floor at any angle in the direction of each of the doors of the
oven. I do not, however, claim as my Invention the above described
method of charging the oven by means of an opening at the top, or of
the use of the hopper, or of the moveable inclined board.
When the oven has been charged, and the coals have been ignited
in the usual way, both the doors and the opening at the top of the
oven must be closed in the usual manner, admitting only by the doors
sufficient air to carry on the combustion necessary for the coking of
the coal. The heat, gas, and volatile matters produced, evolved, and
liberated by the process of combustion, and from the general mass of
coal in the oven, will then rise into the interior of the oven above the
charge of coal, and pass down the two vertical flues above described
into the horizontal flues in the sides and under the floor of the oven;
and thence, so much as may be necessary for creating a sufficient
draught of air for carrying on the requisite degree of combustion, must
be allowed to escape upwards through and out of the two chimnies
above described, the draught being regulated by moveable fire clay
tiles placed on the tops of these chimnies. By these means the heat
arising from the burning coal, instead of being confined in excess at the
top of the oven, or being wasted by being allowed at once to escape
thence out of the oven, will be carried down into the two horizontal
flues above described in the sides of the oven and under the floor,
when it will be applied to the lowest stratum of coal, so as effectually to
coke that portion of the charge, as well as to aid in the transmis-
sion of heat more equally from the whole surface to the centre of the
charge.
For the better regulation of the heat in the oven and under the floor
during the process of coking, by permitting the escape of a portion of
the heat, should it at any time become excessive, the horizontal flues
under the floor must be made to open into the external air by flues
and openings at that end of the oven in which the vertical flues are
placed. These openings, of the same sectional dimensions as the rest
of the horizontal flues under the floor, will be found sufficient for an
oven of the dimensions herein-above described, if made three in number,
and in the position shewn at G, G, G, in Figs. 2, and 4. They must,

page_text: of course, be fitted at their external mouths with proper doors of suit-
able materials for the purpose of confining the heat within the flues, or
allowing it to escape when necessary.
Having now described the nature of my Invention, and in what
manner the same is to be performed, I hereby declare that I do not
confine myself to any particular shape, or size, or number of the
horizontal flues at the sides and under the floor of the oven, or to any
particular number or position in the oven of the vertical flues, and I do
not claim any particular size, or shape, or mode of building or of
working coke ovens, except as herein-after mentioned; that is to say, I
do claim as my Invention the construction of vertical and horizontal
flues in the sides and under the floors of coke ovens, for the purpose of
applying the heat of such ovens, in the manner above described, more
efficiently to the charge of coal to be coked, and more directly to the
lower portion and the under surface thereof, which is next to and upon
the floor of the oven, than has hitherto been practised.
In witness whereof, I, the said Joseph Dunning have hereunto
set my hand and seal, this Sixteenth day of April, in the year of
our Lord One thousand eight hundred and fifty-three.