IMPROVEMENTS IN KILNS FOR BURNING POTTERY AND SALT GLAZE WARE, APPLICABLE ALSO TO THE BURNING OF BRICKS AND TO THE ANNEALING OF IRON
Year: 1869

page_text: LETTERS PATENT to Edward Ensor, the younger, of Woodville, near
Burton-on-Trent, in the County of Stafford, Fire-brick Manufac-
turer, for the Invention of "IMPROVEMENTS IN KILNS FOR BURNING
POTTERY AND SALT GLAZE WARE, APPLICABLE ALSO TO THE BURNING OF BRICKS
AND TO THE ANNEALING OF IRON.""
Scaled the 1st February 1870, and dated the 30th November 1869.
PROVISIONAL SPECIFICATION left by the said Edward Ensor at the
Office of the Commissioners of Patents, with his Petition, on the
30th November 1869.
I, EDWARD ENSOR, the younger, of Woodville, near Burton-on-Trent,
in the County of Stafford, Fire-brick Manufacturer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN KILNS FOR BURNING
POTTERY AND SALT GLAZE WARE, APPLICABLE ALSO TO THE BURNING OF BRICKS AND
TO THE ANNEALING OF IRON," to be as follows:-
This Invention relates to a peculiar construction and arrangement
of what are known as continuous action kilns, and is more especially

page_text: applicable to the burning of pottery and salt glaze ware, also blue
and fire-bricks, and may be employed for annealing iron if desired.
The kiln consists of a number of connected chambers arranged in an
endless series, that is to say, rectangular or circular, for example.
Each chamber is separated from its neighbour by a double or treble
permanent partition made in sections, the middle partition when a treble
partition is used having two or more arched openings, such openings
reaching about mid height up the kiln, the space between the walls of
such partitions being in direct communication with one or more external
fire holes on each side with the feed holes on the top of kiln, and also at
the lower part with the perforated bottom of the adjoining chamber.
The upper portion of the space before referred to opens into the upper
part of the adjoining chamber in the opposite side of the division walls.
In the roof of each chamber a number of feed holes may be provided
situated at the back of the middle partition, which partition is for the
express purpose of preventing any dust from the coal thrown in at the
feed holes passing into the chambers in advance; also certain fire-brick
slabs are built into partitions under the feed holes to catch the fuel and
prevent it falling to the bottom, and so choking up the bottom flues;
also an opening provided with a peculiar damper communicates with a
top flue common to the whole of the chambers and opening into the
chimney. The peculiar dampers above referred to consists of two per-
forated circular slabs of fire-brick laid one on the other. The upper one
is capable of being rotated more or less by means of a rod and handle
for that purpose, whereby the thorofare through the perforations may
be either wholly or partially closed. Above each fire hole an air conduit
is formed, the air entering such conduit through a regulating plug or
valve, and being heated by the direct action of the flame before entering
the chamber. In working this kiln the heat from one chamber passes
down through its perforated floor into the space in the division walls,
and there mixes with the direct heat of the next pair of fire holes of the
chamber in advance. The object of the dampers in the crowns of the
chambers is to facilitate the regulation of the draft in any individual
chamber, so as to increase or diminish the heat therein without inter-
fering with the adjoining chambers. By the combination of the outside
fires, internal feeding, and injection of heated air playing on the flames
of the external fires and on the products of internal combustion, also on

page_text: the inflamable gases passing in from the previous chambers, perfect
combustion is insured, and an intense heat can be obtained and kept up
for any length of time. A peculiar sliding damper may be applied to
the bottoms of the partitions for the purpose of regulating or directing
the draft from chamber to chamber.. These dampers consist of perforated
fire-clay slabs working longitudinally in the bottom of each partition,
the perforations in the dampers coinciding or not, as the damper is
adjusted with other perforations in the sides of the partition walls at
or near the bottom thereof. To avoid unnecessary friction these dampers.
may be supported on antifriction rollers..
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward Ensor in the Great Seal Patent Office on
the 30th May 1870..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
ENSOR, the younger, of Woodville,, near Burton-on-Trent, in the County
of Stafford, Fire-brick Manufacturer, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of November, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Edward Ensor, Her special license,
that I, the said Edward Ensor, my exccutors,, administrators, and
assigns, or such others as I, the said Edward Ensor, my 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, uso, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, and
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
KILNS FOR BURNING POTTERY AND SALT GLAZE WARE, APPLICABLE ALSO TO THE
BURNING OF BRICKS AND TO THE ANNEALING OF IRON," upon the condition
(amongst others) that I, the said Edward Ensor, my exccutor or adminis-
trators, 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

page_text: 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 Edward Ensor, do hereby declare
the nature of my 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:-
My said Invention relates to a peculiar construction and arrangement
of what are known as continuous action kilns, and is more especially
applicable to the burning of pottery and salt glaze ware, also terra cotta,
and blue and fire-bricks, and may be employed for annealing iron, if
desired.
The improved kiln consists of a number of connected chambers
arranged in an endless series, that is to say, rectangular or circular for
example. Each chamber is separated from its neighbour by a double
permanent partition, the space between the walls of such partitions
being in direct communication with one or more external fire holes on
each side, and also at the lower part with the perforated bottom of the
adjoining chamber. The upper portion of the space before referred to
opens into the upper part of the adjoining chamber in the opposite side
of the division walls. In the roof of each chamber a number of holes
may be provided for introducing salt or for inspecting the state of the
fires, such holes being situate between the two walls of the double
partition. An opening provided with sliding dampers or with a plug
communicates between each chamber and a top flue common to the
whole of the chambers and opening into the chimney. Above each
fire-hole an air conduit is formed, the air entering such conduit through
a regulating plug or valve, and being heated by the direct action of the
flame before entering the chamber. In working this kiln the heat from
one chamber passes down through its perforated floor into the space in
the division walls, and there mixes with the direct heat of the next pair
of fire holes of the chamber in advance. The object of the dampers in
the crowns of the chambers is to facilitate the regulation of the draught
in any individual chamber, so as to increase or diminish the heat therein
without interfering with the adjoining chambers. By the combination
of the outside fires and the admission of heated air playing on the flames

page_text: of the external fires and on the products of internal combustion, also on
the inflammable gases passing in from the previous chambers, perfect
combustion is insured and an intense heat can be attained and kept up
for any length of time. A sliding damper is applied to the partitions
behind the fire holes for the purpose of regulating or stopping off the
draught from chamber to chamber. These dampers may consist of
ordinary slabs or of perforated fire-clay slabs, working longitudinally at
or near the botton of each partition, the perforations in the dampers
coinciding or not, as the damper is adjusted with other perforations in
the sides of the partition walls at or near the bottom thereof. To avoid.
unnecessary friction these dampers may be supported on antifriction.
rollers. I find, however, that ordinary sliding slabs will answer for all
practical purposes.
The advantages obtained by the use of my improved kiln are economy
of fuel and the prevention of smoke.
And in order that my said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings,
the same letters of reference indicating corresponding parts in all the
Figures.
Figure 1 of my Drawings represents a longitudinal vertical section of
the several connected chambers constituting my improved continuous
action kiln, the chambers being supposed to be projected in a straight
line; Figure 2 is a sectional plan of the kiln, the left side section being
taken along the line 1-2, in Figure 5, and the right side section being
taken along the line 3-4, in the same Figure; Figure 3 represents a
transverse vertical section of one of the chambers taken along the.
line 5-6, in Figure 1; Figure 4 is a similar section taken along the
line 7-8 of another of the chambers, which is here adapted as a muffler
for terra cotta, Bristol ware, glazed bricks, and other goods of that class;
Figure 5 is a transverse vertical section taken along the line 9-10,
(Figure 1,) shewing the arrangement of the fire holes; and Figure 6 is a
similar section shewing the application of two external fires on each
side of the kiln.
A, A, are the external walls of the kiln, which may be of any shape
capable of being worked continuously, for example, round, oval, oblong,
square, or polygonal, as found most convenient for the locality in which

page_text: it is built. This kiln is subdivided by permanent double partition
walls B, B, into a number of distinct chambers numbered from 1 to 16
on the Drawings. Between the walls of each partition and on both
sides of the kiln there are constructed fire holes C, C, a single fire hole
being made on each side, as shewn in Figure 5, or an additional fire
hole C¹ may be constructed above each of the fire holes C, as shewn in
Figure 6, but this will only be required in cases where high chambers
are used and intense heat is wanted. The floor of each chamber, with
the exception of that one which may have been reserved as a muffler,
and which is numbered 4 in my Drawings, is perforated, as shewn at D,
and communicates with an open space or flue E underneath the said
perforated floor leading direct to the space between the double partition
walls of the next partition in advance, such communication being
established immediately behind the fire, and being capable of being
opened or closed by sliding slabs or dampers a, as shewn clearly in
Figures 5 and 6. In Figure 5 they are shewn full open, whilst
Figure 6 represents them as completely shut. An opening or space b
is left between the top of one of the double walls of the partitions and
the arch of the chamber, as shewn in Figures 1, 5, and 6, in order that
a free communication may be established between the chambers. The
products of combustion from the opposite fires C are kept separate
until they enter the next chamber by the central division wall or pier c,
which is built up inside each partition, as shewn in Figures 2, 5, and 6.
In the crown of cach chamber an opening d is made provided with a
plug e or with a sliding or other suitable form of damper for the purpose
of establishing or shutting off direct communication with the main
flue 1, which is common to all the chambers and opens into a chimney
situate either inside the enclosed space of the kiln or outside thereof,
as shewn in my Drawings, whichever may be found most convenient.
In the top of this flue a number of air inlots f are made, corresponding
in position with the openings d in the roofs of the chambers; these
air inlets being opened or closed as required by means of slabs or
other convenient arrangement of dampers or stoppers. g, g, are a series
of sliding dampers which close the main flue F at any convenient
part for the purpose of facilitating the preliminary drying of the goods
or ware, as herein-after described. G, G, are the entrances to tho
chambers, and h, h, are holes for the introduction of salt between the
double walls of the partitions when requisite and for inspecting the

page_text: state of the kiln; 1, 2, (Figures 5 and 6) are narrow passages constructed
in the brickwork above each fire hole; provided with plugs or dampers
for regulating the admission of air into the upper part of the kiln,
which air becomes heated and mixes with the products of combustion
just as they enter each chamber, and thereby renders the combustion of
the gases more perfect.
The working of this kiln is as follows, reference being had more
particularly to Figure 1 of my Drawings, where the red arrows indicate
the direction of the products of combustion, and the blue arrows that
of the air. The firing is supposed to be carried on in the fire holes C, C²,
which communicate directly with the chambers 1 and 2, the heat passing
onwards through the chambers 1, 2, 3, 5, 6, and 7, which are con-
sequently in process of being burnt and heated up. The chamber 16
in arrear is fully burnt whilst the chambers 15, 14, 13, and 12 are in the
act of cooling. The chamber 11 has cooled sufficiently to be ready for
drawing, the chamber 10 is just filled with fresh or greenware, and is
in the act of drying whilst the chambers 9 and 8 are being filled or set.
The dampers a (Fig. 1) are closed, as shewn, in order to shut off all
communication between the cooling chamber 15 and the chamber 16,
which has been last burnt; the other dampers a", a¹¹, and a¹¹, are also
closed, and all the rest of these dampers are open. Firing is going on
at C and C¹ (Figure 1), and the heat from the last burnt goods in the
chamber 16 passes through the perforated floor of that chamber, and enters
just behind the fire C, where it unites with the products of combustion
from that fire and enters the chamber 1 through the opening 6 in the par-
tition; the heat then passes downwards through the goods and through the
perforated floor of chamber 1 and enters behind the fires at C₁, where it
unites with the products of combustion from C¹ and enters the chamber 2,
whence it passes downwards through the goods and perforated floor and
ascends between the walls of the next partition to enter the upper part
of the chamber 3. As the chamber 4 is here supposed to be used as
a muffler its interior is cut off from direct communication with the
products of combustion from the other chambers by having the damper
at a closed, consequently the products of combustion from the other
chambers pass direct along the closed flucs or passages k, k, in the
bottom of chamber 4 and enter the upper part of the chamber 5 through
the opening, whence they pass downwards through the perforated floor

page_text: of that chamber and through the next partition and opening 6 into the
chamber 6, whence they pass in like manner into the chamber 7, but
as the damper a between that chamber and the chamber 8 is closed
the products of combustion pass into the main flue F to the chimney
through the hole d in the roof of the chamber 7, which is left open for
that purpose. In order to cool the contents of the chambers 15, 14, 13,
12, and 11, and at the same time to dry the goods in the chamber 10, I
admit fresh air into the chamber 15 through the openings f¹ and d',
having previously shut down the dampers g¹ and g" to stop off the com-
munication between this portion of the main flue Fand the chimney. The
fresh air passes in the reverse direction to that previously taken by the
products of combustion, that is to say, it passes downwards through the
partitions and upwards through the several floors of the cooling chambers
until it arrives at the chamber 10 filled with green ware, the caloric
taken up by the air in its passage through the heated goods in the
ceding chambers serving to dry the goods in the chamber 10. The
vapour and heated air escape from the chamber 10 through the opening d
in the roof and pass into the main flue F to the chimney, the dampers
at a being closed so as to shut off all communication with the
chambers 9 and 8 in process of filling. As each chamber is burnt the
fires are lighted in the next fire holes in advance, and those in the rear
are allowed to die out, the several dampers herein-before referred to being
of course opened or closed, so as to carry on the processes of burning,
heating, cooling, and drying, in a continuous manner. When using this
kiln for annealing iron the metal articles are deposited in their usual
envelopes in the chambers above referred to. When the chamber 4 is
in use a fire is lighted at C" above the permanent division a", and
the products of combustion pass over the goods in the chamber 4 and
out through openings and in the opposite wall into the chamber 5.
pre-
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,―
1st. The construction and use of continuous action kilns, consisting
of a number of chambers separated by double walled permanent par-
titions containing fire holes and communicating one with another through

page_text: perforations in the floor and through the space or spaces left between
the double walls of the partitions, substantially as and for the purpose
herein-before described and illustrated by my Drawings.
2nd. The use of the dampers a in the lower part of and between
the double walls of the partitions in combination with dampers or plugs e
in the roofs of the chambers opening in the flue F, as and for the purpose
herein-before described and illustrated by my Drawings.
3rd. The application and use of the air conduits i, i, for the purpose
of enabling heated air to mix in the upper part of the chamber with the
products of combustion from the fires below, whereby greater intensity
of heat is obtained, as herein-before described.
In witness whereof, I, the said Edward Ensor, have to this my
Specification set my hand and seal, this Twenty-seventh day of
May One thousand eight hundred and seventy.
EDWARD ENSOR, JUN". (L.S.)