Improvements in Kilns or Ovens for Firing Potters' Ware, Bricks, Tiles, and such like, and for Calcining various Substances
Year: 1897

page_text: Date of Application, 20th Aug., 1897
Complete Specification Left, 20th May, 1898-Accepted, 20th Aug., 1898
Improvements in Kilns or Ovens for Firing Potters' Ware, Bricks,
Tiles, and such like, and for Calcining various Substances
I, MARK GLOVER MALPAS, Potter, residing at Chanway Cottage, Tunstall, in
the County of Stafford, do hereby declare the nature of this invention to be as
follows:.
This invention relates to kilns or ovens for firing potters' ware, bricks, tiles,
and other such ceramic articles, and for calcining various substances such as
limestone, and consists in certain improvements in their construction, arrange-
ment, and working, having for their primary object the saving of fuel, and
secondary the advancement of the working and the general ease of "setting" the
goods under operation, and the prevention of breakage.
A kiln or oven as now constructed consists generally of a large circular hollow
structure, having a number of furnaces containing fires around it, into which are
placed the piles of seggars containing the articles to be fired. In this arrangement
the heat and products from the fire radiate from the sides of the kiln to the centre.
According to this invention a series or block of kilns or ovens, of approximately
one fourth the size of the ordinary ones, are arranged and combined in a special
manner, by reason of their particular construction, to be worked by a single
furnace, containing a fire, capable of being moved from one oven to another of
the series or block when its turn comes for firing. The travelling fire is carried
upon a truck running upon rails, and is adapted to come centrally underneath
each and every kiln or oven in the series or block. The ovens or kilns com-
prising the series are arranged in two parallel opposite rows, and each one is in
communication with those adjacent to it and a general flue, disposed between the
rows, which is in communication with a chimney; the latter being common to all
the ovens.
The arrangement of ovens, which may be of any number, (preferably in two
rows of twelve each) take the form of a rectangular block, and their bases or
floors are elevated or built up from the ground in order to allow the travelling
fire to run underneath each and every one of them. The main firing flue of each
oven is centrally and vertically disposed through its base or floor, and the travelling
furnace containing the fire is connected thereto by an upwardly moving cylindrical
casing connected to the fire box; a heat-tight joint being arranged between the
firing flue and the circular casing of the fire box by a sand trap. The entrance
to the firing flue of each and every oven is fitted with a swing damper, to close it
when the heat is required to be detained in the oven, but which allows of it being
easily opened for cooling or attaching the fire box of the travelling furnace.
heat tight joint in the swing dampers is made with a sand trap.
A
The construction of each kiln or oven is the same, and therefore it will be only
necessary to describe one and its communication with the next in order to show
the system of working. The oven is a circular fire-brick hollow structure, having
a door, to admit of the putting in and out of the seggars, in its side, and a main

page_text: firing flue, of a large area, centrally and vertically disposed through its base, as
herein before described. The actual floor of the oven is elevated above the main
firing flue, forming a shallow chamber, of a diameter equal to the inside of the
oven, between it and the said flue, into which the products of the fire from the
main flue pass, from whence it is conducted into the interior of the oven by central
and circumferential openings in the floor, the area of which is equal to the area
of the main firing flue. In this manner the heat radiates from the centre to
the sides and also from the sides to the centre, the main portion passing centrally
into the oven.
After playing upon the seggars the heat and products from the fire pass through
central and radially disposed passages in the crown of the oven into circular and
scroll flues, horizontally disposed upon the top or crown of the oven, from whence
they pass to a number of vertical passages, arranged at various points within the
walls of the oven to surround the latter, and into an under flue surrounding the
main firing flue, as before described. This under-flue consists of a number of
circular or radial passages communicating with the under-flue of each adjacent
kiln, or oven, and the common flue to the chimney; damper slides being arranged
between each connection to enable communication to be shut off or made as
required.
Thus the whole of the heat can be utilized by its passage through a system of
kilns.
In the two rows' arrangement, as described, it is intended that a number of
ovens shall be fired whilst a number are cooling off, being emptied, and replen-
ished; and, to illustrate the working, seven is the number that will now be
described as forming the series being fired. The carriage carrying the fire is
connected to the main firing flue of oven No. 1, which is shut off from the
chimney flue but is open to oven No. 2, which is also shut to the chimney flue,
but open to oven No. 3, and so on until oven No. 7, this latter being open to the
chimney flue and shut to No. 8, so that the whole of the products from the fire are
utilized to heat the seven ovens. It is understood that the main firing flues of
ovens Nos. 2 to 7 are closed by the swing dampers before described. When the
firing of oven No. 1 is finished, oven No. 2 is three parts fired, and the travelling
fire is then connected to No. 2 firing flue to finish it, oven No. being then shut
off from oven No. 2 and opened to the chimney flue and atmosphere, if necessary.
Whilst No. 2 oven is being fired No. 8 oven is included in the firing series, and
so on through the system, the firing carriage being turned upon a turn-table at
the end of the row to alter its course to the next row. The products from the
oven being fired pass from the underflue, before described, of that particular
oven to the under flue of the oven next in the series, and from thence into the
interior of the oven, and from the underflue of this oven to the underflue of the
next oven until it reaches No. 7 when whatever is left passes to the chimney.
A central opening is provided, closed by a removable damper, within the crown
of each oven in order to generate a cold current therethrough when required.
In some cases I construct upon the top of each of the ovens, before described, a
secondary kiln which may be found of great service for hardening-on. These
kilns are formed with vertical flues within their walls which are in communication
with radial passages hereinbefore described as within the roof or top of the oven
proper, their outlets being opened and closed in the crowns of the kilus by
removable dampers. A central opening is also formed in the wall dividing the
oven from the kiln built above it, for admitting the products from the fire directly
into the kilns if required, a removable damper shutter being fitted to each for
opening and closing it against the oven proper. The interiors of these hardening-
on kilus can be closed from the ovens proper until such time as only pure com-
bustion is within the ovens proper. It is to be understood that any number of
ovens in the system may be worked, and any number may comprise a system.
One of such ovens, insulated from all the others by the damper shutters, can be
worked with advantage over those now existing, in consequence of the central

page_text: firing, but it is more advantageous to work a larger number as set forth, in order
to have a series being fired and utilizing the fire products, a series cooling off,
and a series being emptied and replenished with seggars.
Dated this 19th day of August 1897
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Agents for Applicant.
Improvements in Kilns or Ovens for Firing Potters' Ware, Bricks,
Tiles, and such like, and for Calcining various Substances.
I, MARK GLOVER MALPAS, Potter, residing at Chanway Cottage, Tunstall, in
the County of Stafford, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer
tained in and by the following statement:-
This invention relates to kilns or ovens for firing potter's ware, bricks, tiles,
and such like ceramic articles, and for caleining various substances, and has
distinct reference to that class of kilns known as "continuous firing" kilns. These
continuous firing kilns generally consist of a number of small kilus or ovens
arranged in a series and so as to be in communication one with the other and to
be progressively fired, cooled, and made ready for firing, and in some cases are
operated by a moving or travelling fire. Such a system of kilns or ovens is set
forth in the Specification of English Letters Patent, No. 1064, of 1875, which were
granted to one Charles Malpas.
It is in the arrangement and construction of such kilns wherein this invention
resides, and the same has for its objects, primarily, a better utilization of the
whole of the fire products and a more uniform heat throughout the entire ovens
surfaces, whilst, secondarily, the provision of supplementary ovens arranged upon
the tops of the ovens proper, for the purpose of being used for "hardening on
the said supplementary ovens being so arranged as to be capable of being heated
or fired by the products from the fire as they leave the ovens proper to pass to
the next oven in turn.
By the aid of the accompanying sheets of drawings, and the reference letters
and figures thereon, the invention will be clearly understood. In the said sheets
a diagrammatic plan of a series or block of kilns arranged according to this
invention is shown in Fig. 1, the said series or block taking the form of two
opposite rows of twelve kilns, each of which is in communication with a common
chimney flue and with those ovens or kilns next or adjacent to it. The said kilns
or ovens in this view are all of a likeness in construction, and each is fired in its
turn by a travelling fire. In this view the kilns are marked 1, 2, 3, and so on,
and represents a chimney flue which is arranged between the rows and which
is in communication with each oven. Fig. 2 represents a longitudinal vertical
section taken through ovens Nos. 1 and 2 and a portion of No. 3, and Fig. 3 is
a horizontal section of ovens Nos. 1. 2. 24, and portions of 3, 22, and 23 (the last
two in diagram only) taken upon the dotted line A, Fig. 2. Fig. 4 is a hori-
zontal section upon the dotted line B, Fig. 2, of the oven No. 1,
whilst Figs. 5 and 6 are horizontal sections upon the dotted lines C, D, respectively,
of oven No. 1 and its supplementary "hardening-on" chamber. Fig. 7 is a
horizontal section of Fig. 2 upon the dotted line E.
The travelling fire q, which is shown in Fig. 2 under the kiln No. 1, travels
upon rails in the ordinary way, and is brought under each kiln or oven pro-

page_text: gressively a turn-table being provided upon each corner of the series or block
of kilns for the purpose of shunting the said fire, or altering its course, as it
proceeds down the rows.
With reference to the aforesaid drawings, each kiln or oven is formed of a
fire-brick hollow structure a having in its side a suitable opening to admit of the
putting in and pulling out of the seggars, and a main firing flue is centrally
and vertically disposed through its base a, the latter being elevated or built up
from the ground to allow of the working of the travelling fire q. The actual floor at
of each oven is elevated above its main firing flue, so as to form a shallow
chamber a, of an equal diameter to the inside of the oven, between it and the said
flue, and this chamber is built with a number of channels or passages 6, (pre-
ferably radially disposed) which communicate from the main firing flue a² to
inlet passages formed within and around the lower portions of the inner
walls of the oven's interior and floor. The passages and channels are clearly
shown in kiln No. 2, Fig. 2, and in Fig. 7; the direction the products from the
firing flue take therein being indicated by arrows. The inlet passages are
preferably inclined as at a8, in order to lead the products from the fire and from
the main firing flue somewhat to the centre of the kiln. A central opening
formed in the actual floor at of the kiln, through which a portion of the products
from the fire pass, and this admits of a central and direct playing of the fire upon
the seggars as well as a circuitous one from the kiln sides.
The crown or
C
تاری
is
ceiling e of the hollow structure a is formed with a central outlet
opening and a number of outlet passages within it, which lead to a combina-
tion of horizontally disposed ring flues, built within the top of the kiln a, and
to a hardening-on" chamber m, which latter may or may not be used with the
kiln a.
The ring flues lead from the opening and passages of the kiln a to a
circular flue common to all parts of the ring flues, and from out of this a number
of vertical passages lead, the said passages being formed within the walls of the
kiln, so as to run the full length of the same and lead into an under flue .
These vertical passages
may be of any number and size, but six only of them are
shown in the drawings, and these are disposed in the walls of the kiln a inter-
mediate between the inlet passages a before described. The underflue is shown
as a number of scroll passages, into which, at points, lead the whole of the vertical
passages, and this under flue communicates both to the chimney flue and to
the radial passages or channels of the kiln next in order for firing, viz.:-
No. 2 kiln, but dampers d d are fitted within the respective passages leading from
the underflue to the parts named, in order that the products from the fire may
be either passed direct into the chimney flue or into the radial passages a² at the
will of the attendant.
Intervening between the under flue and the radial passages 6 is an inner
circular or scroll flue, 8, horizontally disposed and built inside the passages of
cach underflue, and this radially disperses the products from the flue to the
passages af and the central opening, so that they pass into the kiln No. 2
upwards and in the same way as the products pass direct from the fire in kiln No. 1.
Openings are formed in the top of the base and adjacent to the scroll flue 8,
to establish communication between latter and the parts and a³.
It is to be observed that, in their play upon the seggars, the flames or products
from the fire have always an upward tendency, as well as passing, as it were,
twice through each kiln, riz.:-first in the inside and second through its walls.
The hardening-on" chamber m has a number of vertical flues, m², within
its walls, which lead from the circular flue in the top of the kiln a to the
atmosphere or to any desired enclosure, and central openings m³, m' are formed
within the said chamber's crown walls and floor which are provided with
dampers m³, m6, for the purpose of either opening the kiln or chamber to the
atmosphere for cooling, or to close the said chamber to the atmosphere but to open
it to the kiln a at such time as only pure hot air or combustion is within it.
Dampers n, n², control the outlets of the vertical flues m³, and, if necessary,

page_text: similar contrivances may be fitted to the lower portions of the said flues where they
lead from the circular Hue &, so that the "hardening-on" chamber can be shut
off entirely from the products playing through the kiln a and its flues and
passages.
In working, the products from the fire y pass upwards into the kiln No. 1 by
way of the main firing flue a², the central opening a, the radial channels a", and
the inlet passages a, and after playing upon the seggars they pass into the ring
flues by way of the openings and passages 2, Assuming the said products
to be shut off from the "hardening on" chamber, they then pass down the vertical
passages
e into the under-flue and from thence into the inner flue cs of kiln
No. 2, where they are again directed into the interior of this kiln in an upwardly
direction. From this kiln No. 2 they pass into kiln No. 3, by way of the
ring flues c, the vertical passages, and the underflue of kiln No. 2, and the
inner scroll flue of kiln No. 8, and so on through the series, each kiln having
the products passed twice over its boundary surface, riz.:-top, bottom, and sides,
and once inwardly, and once outwardly.
It is to be understood that the kilns can be shut off from each other by the
dampers at any time, and the products passed into the chimney flue, and that the
products from kiln No. 24, pass into the interior of kiln No. 1 in the same way as
described in reference to kilns Nos. 1 and 2.
"
When the hardening on chambers are used, the vertical flues p² are opened to
the circular flue, and the products are allowed to pass therethrough.
It must be observed that although the inner scroll flue is surrounded by its
particular underflue there is no direct communication, as each respectively
receives the products from the preceding kiln and passes it on to the next in
order.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
11
First. In continuous firing kilns or ovens, the combination with the main
firing flues, which lead to the interiors of the kilns and through which the products
from the fire upwardly pass, of vertical passages or flues arranged to surround or
partially surround the inner walls of the said kilns, and to conduct the products
downwardly from the top part of the interior of the one kiln to the other, and to
pass them onto the base of the next in order, and to thus establish communication
between the said firing flues, substantially as set forth.
Second. In continuous firing kilns or ovens, the combination with the main
firing flues a², which lead to the interiors of the kilns and through which the
products from the fire upwardly pass, of vertical passages or flues c arranged to
surround or partially surround the inner walls of the said kilns, and under
flues leading from the said passages to either the chimney flue or the base of the
next kiln in order for firing, substantially as described.
Third. In continuous firing kilns or ovens, the combination of the main firing
flues a², which lead to the interiors of the kilns, vertical passages leading from
the top part of the latter to the base part thereof, under flues c communicating
from the passages either to the chimney flue or to the next kiln in order for
firing, and inner scroll flues communicating from the under flues to the main
firing flues a, substantially as described.
Fourth. In combination in continuous firing kilns or ovens, main firing
flues a, arranged within their bases, central openings a' in the floor of the kilns
directly in communication therewith, radiating passages or channels a communi-
cating from the main firing flues into the interior of the kilns by way of the
inclined passages a, vertical passages or flues c, arranged within the inner walls
of the kilns, and which have communication therewith from the crowns of the
kilns or ovens, under flues c formed within the bases of the kilns, and which
communicate from the said vertical passages either to the chimney flue or the next

page_text: kiln in order for firing, and inner scroll flues e adapted to surround the main
flues a² and to communicate therewith from the underflue in each preceding kiln,
and arranged so as to diffuse the products, substantially as described.
Fifth. In continuous firing kilns or ovens, the combination of main firing
flues a leading to the kilns interiors, ring flues et formed in the crown part thereof,
and vertical passages arranged within the kilns walls and leading from the
said ring flues to the under flues e, substantially as described.
"
Sixth. In continuous firing kilns or ovens; the combination with the kilns
proper, which have outlet openings in their ceilings or crowns, of "hardening on
secondary kilns or chambers m, which are in communication with the kilns proper
and which have vertical flues within their walls and inlet and outlet passages
closed by dampers substantially as set forth.
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also of Liverpool, London, and Manchester,
Patent Agents for the Applicant.
Dated to day o
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also of Liverpool, London, and Manchester,
Patent Agents for the Applicant.