IMPROVEMENTS IN KILNS OR OVENS FOR BURNING BRICKS, TILES, POTTERY WARE, LIMESTONE, CEMENT, AND OTHER SUBSTANCES
Year: 1864

page_text: of Clapham Road, in the County of Surrey, Engineer, for the Invention
of "IMPROVEMENTS IN KILNS OR OVENS FOR BURNING BRICKS, TILES, POTTERY
WARE, LIMESTONE, CEMENT, AND OTHER SUBSTANCES."-Partly a communi-
cation from abroad by Friedrich Hoffmann, of Berlin, in the Kingdom
of Prussia.
PROVISIONAL SPECIFICATION left by the said Humphey Chamberlain,
John Craven, and Hermann Wedekind at the Office of the Commis-
sioners of Patents, with their Petition, on the 24th June 1864.
We, HUMPHREY CHAMBERLAIN and JOHN CRAVEN, both of Wakefield, in the
County of York, Engineers, and HERMANN WEDEKIND, of Clapham Road, in
the County of Surrey, Engineer, do hereby declare the nature of the said
Invention for IMPROVEMENTS IN KILNS OR OVENS FOR BURNING BRICKS. TILES,
POTTERYWARE, LIMESTONES, CEMENT, AND OTHER SUBSTANCES," partly a communi-
cation to us from abroad by Friedrich Hoffmann, of Berlin, in the Kingdom
of Prussia, to be as follows:-
This Invention consists in improvements upon and modifications of the
kilns or ov. ns for burning bricks, tiles, limestone, and other substances, for
which Letters Patent were granted to Alfred Vincent Newton as agent for
the said Friedrich Hoffmann, on the 22nd December 1859, No. 2918.
The first of such modifications consists in erecting such kilns or ovens in

page_text: lines, straight or otherwise, as distinguished from a complete annular or
endless form, and with no perfect continuity of action, such kilns or ovens
communicating with each other to the extent of their length, and having
flues and dampers communicating in a manner similar to those already
described in the before-mentioned Letters Patent, and also communicating
with one or a series of chimneys.
Another part of this Invention consists in constructing the ovens or kilns,
as described in the said Specification, with a second or inner annular chamber,
by which dry or warm air may be taken from any of the heated kilns to any
of the other chambers for the purpose of drying green bricks or other articles
from which it is desired to drive off the moisture.
Another part of this Invention consists in the arranging a flue or flues
passing from the upper part of the kilns or chambers to the chimney, by
which the steam arising from the materials undergoing the process of drying
or heating may be driven off from the articles under treatment.
The kilns or ovens above described may also be worked, when desired,
without chimneys, using in place thereof fans or exhausters.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Humphrey Chamberlain, John Craven, and Hermann
Wedekind, in the Great Seal Patent Office on the 22nd December
1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HUMPHREY
CHAMBERLAIN and JOHN CRAVEN, both of Wakefield, in the County of York,
Engineers, and HERMANN WEDEKIND, of Clapham Road, in the County of
Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of June, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Humphrey Chamberlain, John Craven, and Hermann Wedekind,
Her special license that we, the said Humphrey Chamberlain, John Craven,
and Hermann Wedekind, our executors, administrators, and assigns, or such
others as we, the said Humphrey Chamberlain, John Craven, and Hermann
Wedekind, our executors, administrators, or assigns, should at any time
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,

page_text: exercise,and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
KILNS OR OVENS FOR BURNING BRICKS, TILES. POTTERYWARE, LIMESTONE, CEMENT
AND OTHER SUBSTANGES," partly a communication from Friedrich Hoffmann,
of Berlin, in the Kingdom of Prussia, and partly our own Invention, upon
the condition (amongst others) that we, the said Humphrey Chamberlain,
John Craven, aud Hermann Wedekind, our executors or administrators, by
an instrument in writing under our hands and seal, or under the hand and
seal of one of us or them, 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 we, the said Humphrey Chamberlain, John Craven,
and Hermann Wedekind, do hereby declare the nature of the said
Invention, 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 accompanying Drawings, and to the letters and figures
marked thereon, that is to say :-
Our said Invention relates to improvements upon and modifications of the
kilns or ovens for burning bricks, tiles, limestone, and other substances, for
which Letters Patent were granted to Alfred Vincent Newton, as agent for
the said Friedrich Hoffmann, on the 22nd of December 1859, No. 2918.
The first part of such modifications consists in erecting such kilns or
ovens in lines, straight or otherwise, as distinguished from a complete
annular or endless form, and with no perfect continuity of action, such
kilns or oveus communicating with each other to the extent of their length,
and having flues and dampers communicating in a mauner similar to those
already described in the Specification of the before-mentioned Letters
Patent, and also communicating with one or a series of chimnies.
The second part of this Invention consists in constructing the ovens or
kilns, as described in the said Specification, with a second or inner annular
chamber, by which dry or warm air may be taken from any of the heated
kilns to any of the other chambers for the purpose of drying green bricks
or other articles from which it is desired to drive off the moisture.
The third part of this Invention consists in the arranging a fiue or flues
passing from the upper part of the kilns or chambers to the chimney, by
which the steam arising from the materials undergoing the process of
drying or heating may be driven off from the articles under treatment,

page_text: The kilus or ovens above described may also be worked, when desired,
without chimnies, by using in place thereof fans or exhausters.
And in order that our said Invention may be fully understood, we shall
now proceed more particularly to describe the same, and for that purpose
we shall refer to the several Figures on the Sheets of Drawings hereunto
annexed, the same letters of reference indicating corresponding parts in all
the corresponding Figures.
Fig. 1, on Sheet 1 of our Drawings, represents a longitudinal sectional
elevation of a kiln or oven constructed in a straight line,and working without
continuity of action, in accordance with the first part of our Invention.
a is the brickwork of the kiln, which may be arched on the top or other-
wise constructed, and 6 is the fire-place at one end thereof, the opposite end
opening into a chimney c by a flue d. A number of openings e, e, provided
with close fitting lids or covers are formed at suitable intervals along the roof
of the kiln, such openings being intended for the introduction of small fuel
from the top of the kiln amongst the bricks or other goods. The entire
length of the kiln having been filled with bricks in a fit state for burning, a
fire is lighted in the fire-place b, and air allowed to enter freely through the
fire-door. So soon as the heat at this end of the kilu is sufficiently great to
ensure the combustion of fuel introduced from the top, the supply of fuel is
then commenced through the openings e,c, and the heat is maintained at the
temperature requisite for burning the bricks. The hot air and products of
combustion pass along the entire length of the kiln between the bricks or
other goods stacked therein, thereby gradually heating the same, and finally
pass off by the flue d to the chimney c. So soon as that portion of the
stacked bricks into and amongst which the fuel has been supplied has become
sufficiently burnt, the further supply of fuel thereto is stopped, and the supply
is then carried on through other openings e in advance, so as to mingle the
fuel with the adjoining bricks, which by this time will be sufficiently heated
to ensure the combustion of such fuel. Those bricks which have been
thoroughly burnt are now allowed to cool gradually by the action of the cold air
which passes amongst them and takes up caloric, which it transfers again to
the succeeding bricks on its way to the chimney. In this manner the process
of burning is continued until the extreme end of the kiln has been reached,
some of the goods having in the meantime been drawn and replaced by fresh
ones, so that the kiln will be ready for relighting by the time the last of the
goods is withdrawn. If desired, these kilns may be provided at intervals with.
sliding doors which extend across the kiln, and consequently subdivide it into
a number of separate chambers or compartments; facility would thereby be

page_text: aflorded for making use of one or more of the said compartments as drying
chambers whilst the other portion of the kiln is burning. The drying might
be facilitated by bringing hot air from the cooling portions of the kiln into
the drying chamber for the time being by means of a moveable pipe or flue,
which may be adjusted to any of the holes e in the roof. When the bricks
are sufficiently dry, the doors and flue may be removed so as to bring them
within the direct range of the hot air and products of combustion from the
burning bricks preparatory to their being fired from above, in the manner
herein-before described. In this arrangement flues provided with dampers
should be employed leading from each compartment to separate chimneys or
to one common flue leading to a single chimney, and each compartment should
have near its upper part a flue for carrying off the steam and vapour evolved
during the process of drying.
Figure 2 represents a longitudinal vertical section of a pottery kiln made
in two compartments, and Figure 3 is a corresponding plan of the same;
Figure 4 is a longitudinal section of a similar kiln made in three compart-
ments, and Figure 5 is a plan thereof; any number of compartments may be
used in these kilus, but they are built in a straight line or otherwise, and have
no perfect continuity of action. In these Figures a is the brick work of the
kilns; b, b, b, are fire-places for heating the several compartments 1, 2,
and 3;
is a chimney common to all the compartments; and d is a flue or
aperture opening direct into the chimney from the last compartment of the
series ; e, e, are openings in the roof of the kiln provided with close fitting lids
or covers for the introduction of the fuel into the fire-places 61, 611, which
heat the compartments 2 and 3. The front compartment is heated by the
furnace b, which is supplied with fuel through the door f. The several
furnaces or fire-places may be provided or not with grate bars as required.
g is an air flue extending beneath the floors of all the compartments except-
ing the last of the series, and communicating with the ash-pits of the several
furnaces or fire-places; h, h, are openings for the entrance of fresh air into
the ash-pits, and thence to the flues g. In using these kilns both or all the
compartments are filled with the pottery to be burnt, and a perforated wall of
fire-brick is then constructed between each furnace and its corresponding
compartment to prevent the ashes from coming in contact with the ware. A
fire is now lighted in the furnace b, and the hot air and products of com-
bustion pass through both or the several compartments on their way to the
chimney, thereby heating the whole of the ware in the compartiments which
communicate with one another by the openings atk. k. So soon as the ware
in the first compartment 1 is sufficiently burnt, the door of the furnace b is

page_text: closed so as to exclude air, and the fire-bars are carefully covered over with
earth. The air inlets h, h, are now opened so as to admit the air along the
fluey to the furnace 6', the heat in which escaping from the compartment 1 is
sufficient to effect the combustion of the fuel which is supplied thereto through
the opening e above. The second compartment 2 is now being fired whilst
the ware in the first compartment is gradually cooling. When the wares in
the compartment 2 are burnt, the furnace 6" is lighted in the same way as the
furnace b', and air is supplied thereto by the flue gas before, the process thus
continuing step by step until the whole of the compartments have been fired,
by which time the goods in the first compartment will be ready to be with-
drawn. Above the furnaces 1, 6", a number of projecting bricks are built in
the walls so as to catch the fuel as it is thrown in from the top, and thus
ensure a uniformity of heat throughout the full height of the furnace. It is
obvious that kilus so constructed may be easily transformed into a continuous
kiln on the principle embodied in the Specification of the Patent herein-before
referred to, as shewn by the dotted lines which connect Figures 3 and 5.
Figure 1, Sheet 2, represents a vertical section of a continuous kiln or
oven combined with a second or inner annular chamber, by which dry or warm
air may be taken from any of the heated chambers of the kiln to any of the
other chambers for the purpose of drying green bricks or other articles from
which it is desired to drive off the moisture, as embodied in the second head
of our Invention; and Figure 2 is a sectional plan of the same, the section in
each half thereof being made at different levels. a is the brick work of the
kiln, a portion of the annular burning and drying space of which may be shut
off or separated from the rest by two moveable diaphragms b, b', to form a
drying chamber. The entire kiln is here shewn as capable of being sub-
divided into a number of compartments, numbered consecutively in the Drawing
from 1 to 12 inclusive, although any other number may be used. Each com-
partment is provided with a door at c, c, through which the goods are intro-
duced and removed. From the upper part of the several compartments
extend a series of flues d, converging towards and opening into an annular
smoke chamber c, which surrounds the chimney f, and communicates there.
with by the passages or openings g. The inner ends of these flues inside the
smoke chamber are closed or left more or less open by means of conical plugs
or valves h, which, by being more or less elevated, will regulate the amount of
opening of the flues.
A closed man-hole i (Figure 1) is made in each of these
flues for the facility of cleaning the same. Valves connect any one of these
flues when open with the annular chamber or passage for dry or warm air,
the bottom of such passage communicating by means of valves m with the

page_text: flues, which lead from the lower portions of the compartments of the kiln
to the smoke chamber e, before referred to. These flues are also provided
with conical plugs or dampers o similar to those which are fitted on to the
inner ends of the flues d.
In using this kiln, the goods to be dried and burnt are stacked in the
several compartments, and the firing is carried on in a similar manner to that
described in the Specification of the Patent herein-before referred to; but
according to the present Invention, we propose to convert say, two out of the
several compartments into drying chambers,and to bring the warm air therein
free from ashes or particles of fuel for the purpose of drying the green
bricks or other articles.
In Figure 2, the chambers 3 and 4 are represented as being shut off from
the rest by the doors b, 61, and are supposed to contain green bricks; the
chamber 5 is being filled whilst the goods are being removed from the
chamber 6. The chambers 7, 8, 9, aud 10 all contain burnt goods in the act
of cooling whilst the chambers 11 and 12 are being fired, the hot air there-
from passing through the goods in the chambers 1 and 2, and being obstructed
by the door from entering the drying chambers 3 and 4 direct, it passes off
by the bottom flue n¹ of the series direct to the smoke chamber e, and thence
to the chimney, the plug or damper o' being more or less open for that purpose
according to the draught required. The fresh air enters by the open doors
c', c', passes through the heated goods in the chambers 7, 8, and 9, thereby
cooling the goods, and at the same time taking up caloric. A portion of this
air so heated passes onwards through the chambers 10, 11, 12, 1 and 2, and
thence by the flue n¹ to the chimney, whilst another portion enters one of the
flues d at the mouth thereof d, and as the plug or valve on the inner end
of this flue is closed the heated air enters by the open valve ¹ into the
annular chamber or passage 1. The warm air then traverses the chamber 7,
passes through the only open valvem¹ of the series in the bottom thereof into the
flue of the series (the end of which in the smoke chamber is closed by the
valve o¹¹), and thence to the drying chamber 4 and chamber 3, thereby drying
the bricks or other goods contained therein, and finally escaping at d" by the
flued and open plug or valve h" into the smoke chamber e and chimney f
The whole of the valves h, o, k, and in are kept closel, except those which are
in connection with the flues for the time being, and so soon as the goods in
the drying chambers 3 and 4 are sufficiently dry for burning, the doors b, b,
are removed and replaced at 6", b", thereby exposing the bricks in the.
chamber 3 to the direct action of the heat from the kiln fires, whilst the.
chamber 5 just filled with green bricks forms with the chamber 4 a drying

page_text: chamber. Of course a fresh set of valves or dampers is now opened, and the
operations of burning and drying proceed in a continuous manner.
In
Figures 3 and 4 (Sheet 2) represent respectively a vertical and horizontal
section of a similar kiln provided with a separate collecting flue and chimney
for the abduction of the steam evolved during the drying of the green bricks
or other goods, as embodied under the third head of our Invention.
drying green bricks, the quantity of steam evolved, which varies periodically,
sometimes impedes the draught, more or less, when allowed to mix with the
gases of combustion, but the inconvenience is remedied by leading off the
steam by separate and distinct passages, so that it does not mix with the gases
of combustion until both have ascended some distance up the chimney; this
we accomplish by using a separate steam collector p communicating by
passages q with an internal steam chimney, built inside the smoke chimney f
and extending a convenient height up the inside of the chimney f, and
extending a convenient height up the inside of the chimney, so that the steam
and products of combustion are not allowed to mingle with each other till
they arrive nearly at the top of the chimney.
In Figures 3 and 4, the hot air for drying the bricks enters the chambers
3 and 4 in the manner described in reference to Figures 1 and 2, but in place
of passing off with the steam into the smoke chamber e, they are conducted
by the passage d and valve h into the steam chamber p, and thence into the
internal chimney or tuber, whilst the gases and products of combustion pass
off by the flue n and valve o into the smoke chamber e, and thence by the
passages g into the chimney f surrounding the tube ; in all other respects
this kiln is worked in a precisely similar manner to the kiln shown at Figures
1 and 2 on the same Sheet of Drawings. If desired the slits or openings in
the arches of the annular burning chamber of these kilns or ovens for the
admission of the interrupting doors or dampers b, b', may be dispensed with
by placing the entrance c to each compartment at the end next the door or
damper instead of in the centre of the compartment, as shown in the
Drawings on Sheet 2, and by having the said doors or dampers made up in
several parts; each small enough to be introduced through the entrance c;
by this means the doors 6, 61, may be inserted or removed by hand through
the same apertures by which the kiln is filled and emptied. These doors b, b¹,
may be introduced either from the top, bottom, or sides of the chambers, and
the several parts may be disposed either horizontally or vertically, or they
may be made on the principle of a fan, so as to be inserted through a com-
paratively small aperture, and then expanded or opened out when inside
the kiln.

page_text: In the burning of pottery and other ware which is required to be protected
from direct contact with the fuel and products of combustion, the compart-
ments may be constructed as shown in the detail vertical and horizontal
sections at Figures 5 and 6 (Sheet 2) respectively. In this case a closed
chamber a is built inside each compartment, but having a free passage b
along the sides and under the bottom thereof for the circulation of the heat
and products of combustion. The fuel is fed in from the top through apertures c,
and is kept loose and open by falling amongst the projecting bricks built in
the sides of the fire chamber, as shewn at d. A man-hole e is formed on the
roof of the chamber a for the introduction and removal of the ware, this hole
being provided with a close fitting lid or cover, as shown.
Figures 7 and 8 (Sheet 2) represent a transverse and longitudinal section
of a portion of a kiln intended for burning limestone and other substances
which are liable to shrink considerably during the process of burning. As
this shrinkage or falling of the substances would leave a void space between
the roof and the surface of the substances, the hot gases or products of com-
bustion would, if not checked, pass over the top of in place of amongst the
substances. To obviate this defect, an arch a (Figures 7 and 8) is built so
as to extend downwards from the roof between each compartment sufficiently
far to present a barrier to the gases passing along the surface of the sub-
stances, and compel them to descend into and amongst such substances when
passing under each arch. Another mode of accomplishing the same object is
shown at Figures 9 and 10, wherein the chamber of the kiln is composed of
two side walls a only, with arches 6 at intervals, the substances being covered
over between these arches by a covering of loam and earth c, which descends
with the shrinkage of the substances.
In treating those materials which lose altogether their original form and
fuse or melt to a mass when subjected to a great heat, the fire-places of the
kiln must be enclosed by an open setting of fire-bricks or tubes, as shown
at a,in Figure 11, whereby the choking up of the fire-places will be prevented.
The doors or openings for introducing the goods or materials to be burnt in
the kilns herein-before described may be made either at the top or sides of
the compartments or kiln chamber, and in some cases, as in the burning of
limestone, for example, it will be found advantageous to make the discharging
holes in the bottom, and to have a tunnel or passage beneath, along which
trucks or waggons may be run to receive the contents of the several compart-
ments, as shown by the section, Figure 12.
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

page_text: into effect, we would observe in conclusion that what we consider to be novel
and original, and therefore claim as the Invention secured to us by the herein-
before in part recited Letters Patent is,―
First, the construction of kilns or ovens in lines, straight or otherwise, as
distinguished from a complete annular or endless form, and with no perfect
continuity of action when such kilns or ovens are intended to be worked in the
manner herein-before described.
Second, the combination of a second annular chamber with a circular or
continuous oven or kiln for the purpose of taking dry or warm air from any
of the heated compartments of such kiln to any of the other compartments
with a view to the drying of green bricks or other goods, substantially as
herein-before described and illustrated by Figures 1 and 2 on Sheet 2 of our
Drawings.
Third, the arrangement of the flues of kilns or ovens, whereby the steam
evolved during the process of drying the green bricks or other goods may be
conveyed to the chimney, substantially in the manner herein-before described
and illustrated by Figures 3 and 4 on Sheet 2 of our Drawings.
In witness whereof, I, the said Hermann Wedekind, on behalf of
myself and my said Co-patentees, have hereunto set my hand and
seal, the Twenty-first day of December, One thousand eight hundred
and sixty-four."
HERMANN WEDEKIND. (L.S.)