Improvements in Kilns for use in the Manufacture of Pottery, Porcelain, and Earthenware, and other similar Goods.
Year: 1891

page_text: Date of Application, 21st Mar., 1891
Complete Specification Left, 21st Dec., 1891-Accepted, 23rd Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in Kilns for use in the Manufacture of Pottery,
Porcelain, and Earthenware, and other similar Goods.
I, FRANÇOIS QUERY of Montgesoye, Doubs, France, Manufacturer, do hereby
declare the nature of this invention to be as follows:-
My invention relates to kilus for use in the manufacture of pottery, porcelain
and earthenware and other similar goods and consists in improved arrangements by
which I secure great economy in the consumption of fuel; great economy by the
possible suppression of bars of cast metal especially in the manufacture of glazed
stoneware; great regularity in the heating of the kiln; increased production from
a given number of kilns; considerable reduction in the cost of the drying of the
articles before they are placed in the kiln to be burnt, baked or fired; reduction
in the waste ordinarily resulting in the drying of the articles and a working of a
drying stove regulated to correspond with the working of the kiln itself.
A kiln constructed according to my invention and to be used in the manufacture
of unglazed ware, consists of three portions, the kiln proper, a regenerator or
apparatus for recovering a portion of the heat of the products of the combustion
of the fuel which would otherwise be wasted, and a drying stove for drying the
articles to be afterwards baked, burnt or fired in the kiln. A kiln constructed
according to my invention and intended for use in the manufacture of enamelled
or glazed ware, comprises besides the portions comprised in a kiln for use in the
manufacture of unglazed ware, a supplementary laboratory or kiln-body or
"globe."
The kiln proper, which is preferably circular in form is provided with a certain
number of furnaces regularly arranged. Each furnace may be provided with two
ash-pits separated by means of a partition. Above each ash-pit is placed a grate
formed of steps or benches and bars made of refractory earthenware in consideration
of its small size. The ash-pit beneath each grate is in communication with a
conduit or flue provided with a register or damper by means of which the passage
of air along the said conduit or flue to the grate may be controlled. The air
which passes along the said conduit or flue is heated air which has been heated as
will be hereinafter described by means of a regenerator or apparatus for recovering
some portion of the heat which would otherwise be wasted. In the lower portion
of the ash-pits are formed parts in which water is kept during the operation of
baking, burning or firing. The ash-pits are provided with suitable doors and
openings are provided to allow of the use of a fire-iron to push the fuel from the
higher benches to the lower benches of the grate and to disengage the cinders
accumulating upon the bars of the grate. Glazed openings are provided in order
that the use of the fire-iron may be facilitated and in order that the state of the
fire upon the grate and the progress of the operation of burning, baking or firing
may be observed as may be required. The gases or products of the combustion of
the fuel upon the grates are conducted by suitable flues, passages or openings
and deflected by a suitable partition or wall which extends around the laboratory
or hearth of the kiln in such manner that the laboratory or hearth of the kiln
receives the said gases or products of combustion around its entire circumference.
From the laboratory or hearth of the kiln the gases or products of combustion are
conducted through the perforated bed of the laboratory or hearth and a trough or
passage formed below it and orifices formed through the vault or bottom of the
kiln to the regenerator or recoverer of heat either directly or after passing through
a second laboratory or hearth or "globe” in cases where enamelled or glazed ware
which requires a preliminary baking, burning or firing to "ripen" it is being dealt

page_text: with. The second laboratory or hearth has formed in its vault or bottom openings
sufficient to allow of the passage of the gases or products of combustion issuing
from the kiln. The perforated bed of the second laboratory or hearth is arranged
similarly to the perforated bed of the kiln proper. The laboratory or hearth of
the kiln proper and the second laboratory or hearth or "globe" are provided with
suitable doors to allow the wares which are to be operated upon to be charged into
them and removed when operated upon.
The regenerator or recoverer of heat above mentioned which is provided according
to circumstances beneath the kiln proper or beneath the second laboratory or hearth
or "globe" consists in a bundle or assemblage or group of tubes or pipes through
or around which passes the air to be heated and around or through which pass the
gases or products of combustion issuing from the kiln or second laboratory or
hearth. The tubes or pipes may be of any suitable material, size and form and
may be supported by partitions of refractory earth. From the regenerator or
recoverer of heat the gases or products of conibustion which have issued from the
kiln proper are conducted by flues provided with suitable registers or doors to a
chimney or to a drying stove in which the "green" ware to be afterwards burnt,
baked or fired may be dried. The said drying stove comprises a closed chamber
into which the gases from the kiln may be conducted by means of a conduit or flue
so arranged that the said gases may be distributed evenly throughout the chamber
aforesaid. In the said closed chamber the gases pass over the wares to be dried
and from such chamber the said gases carrying with them the vapour from the
moisture extracted from the "green ware in the drying stove escape through
the perforated bed of the chamber and pass through canals or flues into a collector
or flue by which they are conducted to the chimney above mentioned.
"
When a kiln such as is above described and is intended for the baking burning
or firing of unglazed ware has been charged with the articles to be burnt, baked or
fired the highest bench of each grate is charged with fuel in any suitable manner
and afterwards the stoker or attendant removes from the bars of the grate any
cinders or ashes which may be found thereon and pushes the fuel from bench to
bench. At the commencement of the burning, baking or firing only one half of
each furnace is used and it is only when the articles being baked burnt or fired
attain a "cherry red" heat or tint that the whole of the furnaces are employed at
the maximum activity. During the operation of burning, baking or firing the
gases or products of combustion are conducted from the laboratory or hearth of
the kiln through the regenerator or recoverer of heat and to the chimney without
being caused to pass through the drying stove. As soon as the baking burning or
firing is completed the fires in the grates are extinguished or withdrawn and the
gases or air passing out of the laboratory or hearth of the kiln are conducted
through the regenerator or recoverer of heat and through the drying stove to the
chimney, the flue or passage leading direct from the regenerator or recoverer of
heat to the chimney being closed by means of the register or door provided for the
purpose. The air passing through the laboratory or hearth of the kiln not being
heated by the furnaces becomes gradually of a lower temperature and thus
gradually cools the baked, burnt or fired products and the air heated by passing
through the heated laboratory being afterwards conducted through the drying
stove causes the " green ware placed therein to be dried in readiness for being
fired, burnt or baked. The cooling of the baked, fired or burnt ware and the
simultaneous drying of the "green ware occupy a time equal to or less than the
time occupied in the burning, baking or firing of a charge in the kiln.
و"
Dated this Twentieth day of March 1891.
HOWARD
CHEETHAM,
Manchester, Agent to the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Kilns for use in the Manufacture of Pottery,
Porcelain, and Earthenware, and other similar Goods.
I FRANÇOIS QUERY of Montgesoye Doubs, France, Manufacturer, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
My invention relates to kilns for use in the manufacture of pottery, porcelain
and earthenware and other similar goods and consists in improved arrangements by
which secure great economy in the consumption of fuel, great economy by
rendering it possible to dispense with grate-bars of cast metal especially in the
manufacture of glazed stoneware, great regularity in the heating of the kiln;
increased production from a given number of kilus; considerable reduction in the
cost of the drying of the articles before they are placed in the kiln to be burnt,
baked or fired; reduction in the waste ordinarily occuring in the drying of the
articles and a working of a drying stove regulated to correspond with the working
of the kiln itself.
A kiln constructed according to my invention and to be used in the manufacture
of unglazed ware consists of three portions, the kiln proper, a regenerator or
apparatus for recovering a portion of the heat of the products of the combustion
of the fuel which would otherwise be wasted and a drying stove for drying the
articles to be afterwards baked, burnt or fired in the kiln. A kiln constructed
according to my invention and intended for use in the manufacture of enamelled
or glazed ware comprises besides the portions comprised in a kiln for use in the
manufacture of unglazed ware, a supplementary laboratory or globe.
The kiln proper, which is preferably circular in form is provided with a certain
number of furnaces regularly arranged. Each furnace may be provided with two
ash-pits separated by means of a partition. Above each ash-pit is placed a grate
formed of steps or benches and bars which are made of refractory earthenware as
is rendered possible by the small size of such steps or benches and bars. The ash-
pit beneath each grate is in communication with a conduit or flue provided with a
register or damper by means of which the passage of air along the said conduit or
flue to the grate may be controlled. The air which passes along the said conduit
or flue is heated air which has been heated as will be hereinafter described by
means of a regenerator or apparatus for recovering some portion of the heat which
would otherwise be wasted. In the lower portions of the ash-pits are formed parts
in which water is kept during the operation of baking, burning or firing. The
ash-pits are provided with suitable doors and openings are provided to allow of the
use of a fire-iron to push the fuel from the higher benches to the lower benches of
the grate and to disengage the cinders accumulating upon the bars of the grate.
Glazed openings are provided in order that the use of the fire-iron may be facilitated
and in order that the state of the fire upon the grate and the progress of the
operation of burning, baking or firing may be observed as may be required. The
gases or products of the combustion of the fuel upon the grates are conducted by
suitable flues, passages or openings and deflected by a suitable partition or wall
which extends around the laboratory or hearth of the kiln in such manner that the
laboratory or hearth of the kiln receives the said gases or products around its
entire circumference. From the laboratory or hearth of the kiln the gases or
products of combustion are conducted through the perforated bed of the laboratory
or hearth and a trough or passage formed below it and orifices formed through the
vault or bottom of the kiln to the regenerator or recoverer of heat either directly
or after passing through a second laboratory or hearth or "globe" in cases where
enamelled or glazed ware which requires a preliminary baking, burning or firing to
ripen "it is being dealt with, The second laboratory or hearth or "globe "has
66

page_text: formed in its vault or bottom openings sufficient to allow of the passage of the gases
or products of combustion issuing from the kiln. The perforated bed of the second
laboratory or hearth is arranged similarly to the perforated bed of the kiln proper.
The laboratory or hearth of the kiln proper and the second laboratory or hearth
or "globe" are provided with suitable doors to allow the wares which are to be
operated upon to be charged into them and removed when operated upon.
The regenerator or recoverer of heat above mentioned which is provided according
to circumstances beneath the kiln proper or beneath the second laboratory or hearth
or "globe" consists in a bundle or assemblage or group of tubes or pipes through
or around which passes the air to be heated and around or through which pass the
gases or products of combustion issuing from the kiln or second laboratory or
hearth. The tubes or pipes may be of any suitable material size and form and
may be supported by partitions of refractory earth. From the regenerator or
recoverer of heat the gases or products of combustion which have issued from the
kiln proper are conducted by flues provided with suitable registers or doors to a
chimney or to a drying stove in which the "green ware to be afterwards burnt,
baked or fired may be dried. The said drying stove comprises a closed chamber
into which the gases from the kiln may be conducted by means of a conduit or flue
so arranged that the said gases may be distributed evenly throughout the chamber
aforesaid. In the said closed chamber the gases pass over the wares to be dried
and from such chamber the said gases carrying with them the vapour from the
moisture extracted from the "green ware in the drying stove escape through the
perforated bed of the chamber and pass through canals or flues into a collector or
flue by which they are conducted to the chimney above mentioned.
"
"
When a kiln which is constructed in the manner above described and is intended
for the baking, burning or firing of unglazed ware has been charged with the
articles to be burnt, baked or fired the highest bench of each grate is charged
with fuel in any suitable manner and afterwards the stoker or attendant removes
from the bars of the grate any cinders or ashes which may be found thereon and
pushes the fuel from bench to bench. At the commencement of the burning, baking
or firing only one half of each furnace is used and it is only when the articles being
baked, burnt or fired attain a 66
cherry red" heat or tint that the whole of the
furnaces are employed at the maximum activity. During the operation of burning,
baking or firing the gases or products of combustion are conducted from the
laboratory or hearth of the kiln through the regenerator or recoverer of heat and
to the chimney without being caused to pass through the drying stove. As soon as
the baking, burning or firing is completed, the fires in the grates are extinguished
or withdrawn and the gases or air passing out of the laboratory or hearth of the
kiln are conducted through the regenerator or recoverer of heat and through the
drying stove to the chimney, the flue or passage leading direct from the regenerator
or recoverer of heat to the chimney being closed by means of the register or door
provided for the purpose. The air passing through the laboratory or hearth of
the kiln not being heated by the furnaces becomes gradually of a lower temperature
and thus gradually cools the baked, burnt or fired products and the air heated by
passing through the heated laboratory being afterwards conducted through the
drying stove causes the " green ware placed therein to be dried in readiness for
being fired, burnt or baked. The cooling of the baked, fired or burnt ware and
the simultaneous drying of the "green ware occupy a time equal to or less
than the time occupied in the burning, baking or firing of a charge in the kiln.
A kiln constructed according to my invention and intended for the burning,
baking or firing of earthenware articles which are unglazed or do not need to be
subjected to a special burning baking or firing in order that the glazing or
enamelling may be accomplished is illustrated in the accompanying drawing in
which
"
"
Fig. 1 is a longitudinal section of a kiln, Fig. 2 is a transverse section of one of
the furnaces of the kiln, and Fig. 3 is a horizontal section taken on the level
indicated by the lines 1-2, and 3-4 of Fig. 1,

page_text: The kiln illustrated in the said figures comprises three parts, the kiln proper, the
regenerator or recover of heat and the drying stove, but when the kiln is intended
for burning, baking or firing articles which require to be burnt, baked or fired in
two operations in order to be glazed or enamelled the kiln comprises besides the
three parts aforesaid a supplementary laboratory or globe in which the glazing or
enamelling is accomplished. The kiln proper is preferably made of a circular form
as such form ensures greater regularity in the baking and ensures greater solidity
of the whole but the kiln may be made of any other form which may be desirable.
In the kiln are provided a suitable number of furnaces A which are arranged so
that they are distributed at regular intervals arcund the kiln in order that the
necessary regularity in the heating of the kiln may be more readily attained.
Each furnace A is divided by means of a partition a of refractory bricks, so that it
is provided with two ash-pans B. Above each ash-pan B is a grate formed of
benches and bars c. The benches b and bars c being of small size are made of
refractory earthenware. The ash-pan B under each grate communicates with a
vertical conduit C furnished with a register or door in order that the supply of
air for the combustion of the fuel upon the grate may be regulated. The air
supplied to the fuel upon the grates of the kiln is during most of the time that the
kil is at work heated air which has been heated in the manner to be more fully
described hereinafter. The bottom of each ash-pan is made in the form of a water-
tight basin or hollow and is kept charged with water during the whole duration of
the baking of a charge of earthenware in the kiln. Doors which fit accurately but
are not shown in the drawing are employed to shut off the ash-pans B from the
external air. The said doors are lined with refractory brick. Above each of the
said doors a hole is provided in order to allow a fire-iron to be employed to push
the fuel in the grates from the higher benches to the lower benches and to disengage
the accumulated cinders from the bars c and at the side of the said hole a glazed
opening is provided to allow the working of the fire iron aforesaid to be observed.
A glazed opening is also arranged in the register at the mouth of the furnace in
order that the progress of the fire may be observed and other glazed openings are
also arranged in the wall of the kiln in order that the progress of the burning,
baking or firing being performed in the kiln may be observed. The gases or the
products of the combustion of the fuel in each of the grates escape by the opening d
which is formed above such grate and communicates with an opening formed
between the wall of the kiln and a wall D formed around the central laboratory or
hearth E of the kiln. The opening d forms for each grate a kind of hopper of
which the height is represented by the height of the wall D. In this manner the
laboratory or hearth E of the kiln receives the gases or products of combustion on
all its circumference and in the form of a continuous sheet. The said gases or
products of combustion are afterwards conducted by the troughs c¹¹ extending
beneath the perforated bed S of the kiln and the holes oo which communicate with
the space beneath the lower arch of the kiln to the regenerator or recoverer of
heat directly or by traversing an intermediate laboratory or "globe" which is
arranged between the kiln proper and the regenerator or recoverer of heat when
glazed or enamelled wares which require to be subjected to two baking, burning or
firing processes, one to bring them into the condition of "biscuit" and the second
for the vitrification of the glaze or enamel, are to be produced. This second
laboratory or hearth is made of the same capacity as that of the kiln proper and is
provided in its upper vault or roof with holes sufficient to allow of the gases or
products of combustion issuing from the kiln and such second laboratory or "globe"
is provided with a perforated bed arranged like that of the kiln proper above
described, which allows the gases or products of combustion to pass to the
regenerator or recoverer of heat. The laboratory or hearth of the kiln is provided
with a suitable door by means of which the wares to be baked burnt or fired may be
charged into the kiln and removed therefrom when baked, burnt or fired and if a
second laboratory or hearth or "globe" is employed such second laboratary or
hearth or "globe" is also provided with doors by means of which the wares to be

page_text: glazed or enamelled may be introduced therein and after being fired or baked be
removed therefrom.
The regenerator or recoverer of heat which is according to circumstances situated
beneath the kiln proper or beneath the second laboratory or hearth or "globe
consists in a bundle or assemblage or group F of tubes or pipes which may be round
or square or of any other suitable form and be made of refractory earthenware or
any other suitable material and be connected together in any suitable manner such
as by means of collars or flanges or sockets or sleeves. The tubes or pipes forming
the bundle, assemblage or group F of tubes are supported by means of partitions
made of refractory bricks. The products of combustion or hot gases issuing from
the laboratory E of the kiln or from the supplementary laboratory or "globe" when
such is employed circulate around and impart heat to the pipes or tubes forming
the bundle, assemblage or group F and pass through the grating K which occupies
all the lower part of the regenerator or recoverer of heat. The air which is to be
supplied to support the combustion of the fuel in the furnaces A of the kiln passes
through the passage or flue G to the tubes or pipes forming the bundle assemblage
or group F and in passing through such tubes or pipes becomes heated and then
passing into the circular passage H which extends around the greater part of the
interior of the lower part of the kiln passes by means of the vertical conduits C to
the furnaces A of the kiln. The hot gases or products of combustion issuing from
the kiln or from the supplementary laboratory or "globe" when such is employed
thus serve to heat the air which is to be supplied to the furnaces of the kiln.
After passing through the grating K the products of combustion or hot gases
pass into the flue and may be conducted either through the flue J¹ to the chimney I
or by means of the flue M to the drying stove which will be further described
hereinafter. In order that the products of combustion or hot gases may be caused
to pass to the chimney in either of the said directions as may be required from time
to time the flues J' and M are provided with registers ² and by means of which
the passage of the products of combustion or gases along either of such flues may
be permitted or interrupted from time to time as may be desirable.
Instead of passing around the tubes or pipes forming the bundle F which
constitutes the regenerator or recoverer of heat the gases or products of combustion
issuing from the kiln or from the supplementary laboratory or globe may pass
through the interiors of and heat such tubes or pipes while the air to be heated
passes around such tubes or pipes and becomes heated thereby.
יי
The drying stove which forms part of the kiln illustrated in the accompanying
drawing comprises a closed chamber L into the centre of the interior of which
opens a chimney N which forms the termination of the flue M. The gases or
products of combustion issuing from the chimney N which are still hot spread over
the raw or "green wares to be dried which are arranged on the perforated bed St
of the drying stove and dry such wares and pass through the said perforated bed S¹
into the canals or conduits & from which they pass by the collector or flue P to the
chimney I through which they escape and carry with them the vapour from the
moisture extracted from the wares being dried
When the kiln illustrated in the accompanying drawing is to be used the
laboratory or hearth of the kiln is filled with the wares or articles to be baked
burnt or fired. The uppermost of the benches b of each of the furnaces A is
charged with fucl.access to the said bench being obtained by the corresponding
door or register being raised or in any other manner. Before the charge of fuel
in each furnace is worked out the stoker disengages any cinders which
may be upon
the bars and pushes the fuel from bench to bench.
At the commencement of the operation of burning, baking or firing one half only
of each furnace is used. It is only when the products or wares being burnt, baked
or fired assume a 66
cherry red" heat or tint that the furnaces are put into full
activity and that a large or full fire is used. The registers or doors are opened
to the extent necessary for the supply of air to support the combustion of the fuel
and the registers or doors are kept closed except when the furnaces are being

page_text: charged with fuel. During the continuance of the burning, baking or firing the
register or door in the flue M communicating with the drying stove is kept
closed and the register or door 12 in the flue J leading to the chimney I is
open.
"
*
"
As soon as the burning, baking or firing of the wares in the kiln is completed the
fires in the furnaces are extinguished or withdrawn and the register in the flue M
leading to the drying stove is opened and the register or door in the flue J¹
leading to the chimney I is closed. An active circulation of hot air through the
regenerator or recoverer of heat, the kiln and the drying stove is thus established.
The temperature of this air not being maintained by fires in the furnaces A
gradually falls and thus a gradual cooling of the baked, burnt or fired wares in the
kiln and a perfect drying of the raw or green wares in the drying stove is
attained in a period of time equal to if not less than that occupied by the baking,
burning or firing. The cooling of the kiln constructed according to my invention
can be regulated with the same precision as the heating thereof. In some cases the
partition a may be dispensed with and in such cases the adjustment of the fires to
the needs of the baking, burning or firing of the articles or wares in the kiln will
need to be accomplished by a greater or less number of the benches of the grates
of the furnaces A being supplied with fuel. By means of a kiln constructed
according to my invention the burning, baking or firing of a charge of wares
inclusive of the charging and discharging of the kiln may be accomplished in
seventy-two hours at the most. In a kiln constructed according to my invention
the air which is passed into the kiln to cool the baked burnt or fired wares or
articles therein having passed through the regenerator or recoverer of heat and is
consequently heated to a suitable extent before passing into the kiln. By the..
benches and grate-bars being formed of refractory earthenware the melting of
the grate-bars which might occur if they were made of cast iron guarded against
and this is particularly of advantage in the manufacture of glazed stoneware.
(
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The improved kiln above described which comprises a kiln proper, a regene-
rator or recoverer of heat and a stove in which the articles or wares to be burnt,
baked or fired may be dried, all arranged, employed and operating for the purposes
and substantially in the manner hereinbefore described.
2. The arrangement of the kiln proper hereinbefore described comprising
furnaces A of any number equally distributed around the laboratory E of the kiln
and sending into such laboratory a regular sheet of hot gases or products of
combustion a wall D to guide and distribute the hot gases or products of
combustion, and a perforated bed S all arranged and operating substantially in the
manner hereinbefore described and combined or not combined with a supple-
mentary laboratory_or globe" of an arrangement substantially similar to that
of the laboratory E for the baking, burning or firing of glazed or enamelled
wares.
<<
3. In combination with the kiln proper whether provided or not provided with a
supplementary laboratory or "globe" for the burning, baking or firing of enamelled
or glazed wares the hereinbefore described arrangement of the regenerator or
recoverer of heat formed of a bundle, assemblage or group F of tubes or pipes
situate below the bed S of the kiln or below that of the supplementary laboratory
or "globe" according to circumstances as hereinbefore described and enabling the
heat of the gases or products of combustion issuing from the kiln to be utilized in
the heating of the air to be supplied to the furnaces of the kiln.
4. In the kiln proper above described the arrangement of furnaces which are
provided with grates formed with benches and bars c formed of refractory
earthenware so that the extent and activity of the fires thercon may be readily
controlled in accordance with the requirements of the burning, baking or firing

page_text: and are divided or not divided by means of partitions a of refractory earthenware
and are supplied with heated air which has received its heat from a regenerator or
recoverer of the heat of the hot gases or products of combustion issuing from the
kiln substantially as hereinbefore described.
5. In combination with the kiln proper above described the hereinbefore
described arrangement of drying stove for utilizing in the drying of wares or
articles which are to be afterwards baked, burnt or fired the heated air issuing
from the kiln while the baked, burnt or fired wares or articles therein are being
cooled by the current of air which has passed through the regenerator or recoverer
of heat the temperature of which current of air gradually falls as less heat is
imparted to the regenerator or recoverer of heat by the air issuing from the kiln
substantially in the manner herein before described.
Dated this Nineteenth day of December 1891.
HOWARD
CHEETHAM,
Manchester, Agent to the Applicant.