IMPROVEMENTS IN KILNS
Year: 1877

page_text: LETTERS PATENT to Thomas Carder, of Torquay, in the County of Devon,
Brick Manufacturer, for the Invention of "IMPROVEMENTS IN KILNS."
PROVISIONAL SPECIFICATION left by the said Thomas Carder at the Office
of the Commissioners of Patents on the 9th January 1877.
THOMAS CARDER, of Torquay, in the County of Devon, Brick Manufacturer.
"IMPROVEMENTS IN KILNS."
This Invention consists in improvements in the construction of kilns, and method
of working the same, applicable for drying and burning fire and other bricks, tiles,
pottery, lime, and other similar materials, whereby the surplus heat after burning
the bricks or other articles is caused to flow or pass on from kiln to kilu. In
addition to this the heat stored up in the sides and arches of the kilns or chambers
is brought into profitable use for drying the newly made or green bricks and other
articles of pottery or fire ware which are dried in vaulted stoves or drying
chambers; the bricks or other articles or materials are according to this system
dried and burned in a more regular and perfect manner than hitherto, and at a
considerably less expense. In addition to which the annular kiln constructed
according to this Invention may be quickly built and at a great saving in first
cost as compared with other kilns.
I
In carrying out my Invention I construct a series of vaulted kilns or chambers
arranged in the form of a double horse-shoe or an ellipse, so as to form a con-
tinuous kiln, having flues at convenient distances apart in communication with a
suitably placed chimney or shaft, such flues being regulated by dampers.
I construct two or more drying stoves or ovens arranged contiguous to and in
communication with the main flue and (by means of the main flue and a cooling
chamber flue) with the kiln, thereby allowing the waste heat from the burning
compartments and the heated gases from the kilns or chambers in which the bricks
are cooling to be conveyed through the said drying stoves before passing to the
chimney; or the heated gases from the cooling chambers may be conveyed below
the floor of the drying stoves by a series of small flues.
In the crown of the kilns or chambers I form lateral slits of suitable length and
width, and at the required distance apart. These slots are for firing or assisting in
firing the burning chambers, and thereby causing a more equal distribution of heat

page_text: "
in each kiln than can be obtained by known methods. The slits are closed by
plates of sheet iron, so as to fall over these lateral apertures evenly with the top of
the kiln; or they may be so fixed as to form a V groove or gutter in the slits when
closed and into the open part thereof the required quantity of coal dust is readily
scraped and allowed (as desired) to fall through the slits to the bottom of the
burning chamber by simply turning the said iron plates on their axes, and as soon
as the coal has passed through the slits the plates are allowed to fall into their
normal positions, so as to close the slits.
For instantaneous firing I connect the handles of the slit plates by means of
slight connecting rods, so that by simply reversing the handles or levers at one end
the required number of feeding slits are fed at one and the same time. This
arrangement ensures a more perfect and uniform distribution of the fuel than can
be obtained by the use of the ordinary round stoke holes, and prevents the
admission of cold air and accumulation of fuel in places, thereby avoiding any
choking or slagging amongst the bricks.
In combination with these slits I employ when burning refractory clays, such as
fire or blue bricks, one, two, or more bottom or side bar furnaces, which are fired
through perpendicular or oblique openings extending to the top of the kilns, or
through oblique openings extending to the exterior of the side walls or buttresses,
and at the required height. A draw plate to pull out and push in is placed about
a foot from the top of each opening, and an iron or fire-clay cover to exclude the
external air, thereby allowing the charge of coal to be introduced without the
admission of the cold external air.
For red bricks the bottom or side furnaces may be dispensed with and the
openings stopped up, but such side furnaces in connection with top slits will be
found exceedingly economical for burning white or blue bricks and fire-clay ware
generally channels or spaces are arranged under the slits, and a "drop" arch is con-
structed on the draught side of each of the slits, which prevents the passage of any
coal dust over the bricks to be burned.
The improved kiln is made continuous either by means of a reduced chamber,
the top of which is on a level (or nearly so) with the drying stove, or by means of
a large flue or funnel passing from the last to the first chamber, the high degree of
temperature being maintained or increased during such passage by the aid of firing
through the top slits in such flue or funnel, which I also fill with green bricks to
be burned. On either side of the walls of the drying stove or oven I construct
brick ledges at suitable distances apart for receiving boards or shelves filled with
soft or green bricks direct from the moulders or brick machines; the tray of
boards loaded with bricks is placed upon a trolley and elevated by means of a
central screw, the trolley being run into the drying flue the screw is lowered until
all the boards rest upon the ledges. The newly made bricks may be run direct
into the drying flues and stacked from end to end, or on trolleys fitted up with shelves.
By either of these methods it is only necessary to handle the bricks once before
going to the kiln.
When it is desired to build a cheap continuous kiln for small brickyards, or for
increasing the production at large brickworks, I form the kilns into a twelve-sided
figure of the nature of a parallelogram, thus
and also when the site for
the kiln and other conditions suit I construct the kiln somewhat in the form of a
lozenge or diamond, thus
>
but having two or more sides or indents formed
at the apex of each of the four corners for the purpose of conveniently placing the
side fires and wicket openings; both of these kilns give all the advantages of the
annular principle, and the method of firing by means of the slits in the crown and
side fires (or either) is similar to that herein-before described.
A flue having a damper leads from each chamber or kiln into a smoke chamber,
from thence the smoke and gases are drawn into the main chimney, which by
preference is placed in the centre of the series of kilns or burning chambers.

page_text: I so arrange the dampers near the angles of each chamber that any single
chamber can be burned separately and distinct from the rest, and thereby convert
it into an ordinary square kiln, with the advantage however of using the slits in
addition to the bottom or side fires, thereby causing an equal distribution of. heat
throughout the kiln by means of a small amount of fuel; soft bricks in any part of
the kiln can be thus avoided.
At the sides of the kilns I construct a floor or chamber that shall serve the
purpose of a drying stove, which stove or series of stoves are capable of drying all
the bricks required to keep the kilns in operation. The stoves are warmed to any.
required temperature for drying purposes without any additional cost and by means
of the heat generated in the kilns during the process of burning the bricks. This
surplus heat is directed or drawn into the drying stoves by means of pipes or flues.
connected with the kilns in addition to the radiated heat from the same.
This description of annular kiln and drying stove can be quickly built, and at.
about one half the cost as compared with other annular kilns capable of burning
the same quantity of bricks,
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Carder in the Great Seal Patent Office on the 9th July
1877.
THOMAS CARDER, of Torquay, in the County of Devon, Brick Manufacturer.
"IMPROVEMENTS IN KILNS."
This Invention consists in improvements in the construction of kilns and method.
of firing the same by means of specially contrived lateral slits in connection with or
without bottom side fires, applicable for drying and burning fire and other bricks,
tiles, pottery, lime, and other similar materials," whereby the surplus heat after.
burning the bricks or other articles is caused to flow or pass on from kiln to kiln
and then directed at will in its passage to the chimney into vaulted drying
chambers peculiarly arranged so as to profitably utilize such surplus heat. The
bricks, or other articles or materials, are according to this system dried and burned
in a more regular and perfect manner than hitherto, and at a considerably less
expense.
In carrying out my Invention I construct a series of vaulted kilns or chambers
arranged in the form of a double horse-shoe, or an ellipse, or in some cases round, or.
otherwise, so as to form a continuous kiln, having flues at convenient distances
apart in communication with a suitably placed chimney or shaft, such flues being
regulated by dampers.
I construct one, two, or more drying stoves or ovens arranged contiguous to and
in communication with the main flue and (by means of the main flue and sometimes
a cooling chamber flue) with the kiln, thereby allowing the waste heat from the
burning compartments and the heated gases from the kiln or chambers in which the
bricks or other goods are cooling to be conveyed through the said drying stoves
before passing to the chimney, or the heated gases from the cooling chambers may
be conveyed below the floor of the drying stoves by a series of small flues.
In the crown of the kiln or chambers I arrange a special contrivance for firing by
means of lateral slits of suitable length and width and at the required distances.
apart. These slits are for firing or assisting the firing of the burning chambers, and
thereby causing a more equal distribution of heat in each kiln than can be obtained by
hitherto known methods. These slits are closed by suitably contrived plates turn-
ing upon their axes or otherwise within or above the slit openings. These slits I
claim as novel, and will be found to answer the purpose better than any hitherto
known modes of dome or internal firing arrangements. These slits may be extended
from side to side of the burning chamber and the fuel allowed to fall by simply.
raising, pulling out, or turning the plates or valves on their axes. The fuel thus

page_text: being distributed along the whole width of the kiln will give more uniform results
and prevent waste by slagging, the latter being a common occurrence in kilns fired
in small spots or areas by means of stoke or firing holes.
. In combination with these slits I employ when burning refractory clays one, two,
or more bottom or side bar furnaces, which are fired through perpendicular or
oblique openings extending to the top of the kilns or through oblique or other open-
ings extending to the exterior of the side walls or buttresses, and at the required
height. The side furnaces at internal buttresses I supply with external air by
means of a pipe flue which I carry to a point below the fire-bars.
For red or mild clays the bottom or side fires may be generally dispensed
with. I sometimes make my improved kiln continuous by means of a reduced
chamber, the top of which is on a level, or nearly so, with the drying stove, or
as otherwise convenient. On either side of the walls of the drying stove or
oven I construct brick ledges at suitable distances apart for receiving boards
or shelves filled with soft or green bricks direct from the moulder's or brick
machines; the tray of boards is placed upon a trolley and elevated by means
of a central screw, the trolley being run into the drying flue; the screw is
lowered until the boards rest upon the ledges. The newly made bricks may
be run direct into the drying flues and stacked from end to end, or on trolleys
suitably fitted up. I prefer to generally construct my improved kiln so as to
have from twelve to fourteen chambers or compartments, each compartment
being divided off by a brick partition turned on
one or more arches to give
sufficient open space at the bottom and thereby allowing the flow of heated
gases or flame to pass from chamber to chamber, or when this opening is closed
by specially contrived travelling door worked as a damper from the side or top of
the kiln, then it is shut off from the setting and drawing compartments.
But to make my Invention better understood, I will now proceed to more
particularly describe the same by reference to the accompanying Drawings, in
which―
Figure 1, Sheet 1, is a horizontal section of a continuous kiln constructed accord-
ing to my Invention; Figure 2, Sheet is a transverse section of same, shewing the
burning chambers connected with the main flue and drying tunnels; also the method
of arranging the side firing channels.
0
Figure 3, Sheet 3, is a longitudinal section of the drying tunnel as connected
with the main flue and burning chambers.
Figure 4, Sheet 3, is a longitudinal section shewing the burning chambers and
the arrangements of feeding or firing slits.
Figures 1, 3, and 4, are drawn to a scale of about one-eighth of an inch to the
foot; and Figure 2 to a scale of about one-quarter of an inch to the foot.
Similar letters in all the Figures are used to represent similar parts.
C, C, are the burning chambers; F, F, the flues leading from the burning
chambers to the main flue; S, S, are the side fire or stoke holes; L, L, the feeding
holes and lateral slits; D, F, the floor of the drying tunnel; M, F, the main flue;
K, chimney or shaft; A, air flue for supplying external air to the inner furnaces;
H, H, hot air flues passing under floor of drying tunnel for utilizing waste heat; T, D,
the travelling door for connecting or shutting off burning chambers; D, dampers;
O, openings for the admission of hot air to the drying tunnels.
The method of working is as follows:-Commence to fill chambers Nos. 1, 2, and
3, with bricks or other goods to be burnt or baked, and after having filled up the
wickets, shut off these chambers from the rest of the chambers by pushing the travel-
ling door T, D, of No. 3 chamber in towards the inner wall, and make air-tight by
daubing and filling up all crevices; then draw up dampers of chambers Nos.
and 3,
as the draught may require, and commence with bottom fires at the beginning of
No. 1 chamber, and continue to increase the firing until the whole mass ofgoodsto
be burnt is sufficiently hot (red hot) to ignite small coal which may now be allowed
to fall through the slits L on top of the burning chamber and work up to required
pitch of heat. As soon as a red heat. has passed on to Nos. 2 and 3 chambers

page_text: respectively, commence to fire from the top by means of the slits L, over these
chambers, and also the bottom fires may be raised, if necessary, until hardening
heat has been attained. Meanwhile proceed to set or fill up No. 4 chamber; when
full, push in the travelling door at its far end, make air-tight, close up the wicket
or clammin, pull out travelling door of chamber No. 3 to effect communication,
push down damper of flue F of chambers Nos. 1 and 2, and pull up damper
of flue of No. 4 chamber, and continue to fire until ready to "put on
" No. 5.
Proceed with each remaining chamber as with chamber No. 4, and cease to
fire Nos. 1 and 2, as necessary. Heated air can be passed into drying
chamber D, F, by drawing a damper communicating with the main flue at O.
Close the damper D at far end of the main flue, and divert the draught of main
flue M, F, by means of the opening O up into and through D, F, and on from thence
to wiffin spaces in shaft or chimney, or yet again into M, F, at a point beyond
damper already closed at far end, and so direct on to main flue of shaft. After the
temperature has cooled down in chambers Nos. 1 and 2 the travelling doors of these
chambers can be pushed in to prevent too much cold air passing on to burning
chambers Nos. 4 and 5. The whole hot air passing off in process of cooling can be
carried on beyond the burning chambers into chambers filled with green or newly
made bricks so as to gently warm them up ready for the intenser heat of the
burning chamber when necessary to effect communication with it. Also the heated
air of cooling chambers can be taken away by a series of small flue spaces under-
neath the floor of the drying flue or chainber D, F.
Having thus described the nature of my said Invention, and the best means
with which I am acquainted for carrying the same into effect, I wish it to be
understood that I do not confine myself to the precise details herein laid down
and shewn in the accompanying Drawings, as the same may be varied without
departing from the peculiar character and principle of my Invention, but what I do
claim and intend to be protected by the herein in part recited Letters Patent is,―
Firstly. Tlie general arrangement and construction of kilns whereby fuel is
economized and a better result obtained than hitherto, substantially as herein-before
described and represented in the accompanying Drawings.
Secondly. I claim the feeding or firing slits constructed in the crown or arch of
each burning chamber.or kiln for effecting equal distribution of fuel across and
throughout the same, as herein-before described.
Thirdly. The improved drying chamber contiguous to and in connection with the
main and other flues, and the method of constructing the divisional walls between
the burning chambers, together with position of wells or apertures leading to flues
directly under the same, substantially as herein-before described and represented in
the accompanying Drawings.
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Fourthly. The method of supplying external air to the internal side fires, and the
mode of charging or feeding the side fires of bar furnaces, as herein-before described
and represented in the accompanying Drawings.
In witness whereof, I, the said Thomas Carder, have hereto set my hand and
scal, this Sixth day of July, in the year of our Lord One thousand eight
hundred and seventy-seven.
Witness,
GEO. WM. SPAWFORTH,
6, Abbey Crescent,
Torquay.
THOMAS CARDER. (L.S.)