Improvements in Continuous Ceramic Furnaces with Heated Movable Soles.
Year: 1896

page_text: Date of Application, 8th Aug., 1896.
Complete Specification Left, 7th May, 1897-Accepted, 3rd July, 1897.
PROVISIONAL SPECIFICATION.
Improvements in Continuous Ceramic Furnaces with Heated
Movable Soles.
I, HENRI STURM of 16, Rue Drouot, Paris, in the Republic of France, Engineer,
do hereby declare the nature of this invention to be as follows:-
Efforts have already been made to produce continuous ceramic furnaces with
movable floors or soles, but none of such furnaces have as yet come into practical
use, because they were not rationally designed as regards details of construction,
which in this arrangement, more than in any other, are of essential importance.
In order that a furnace of this kind may be practicable and effective it is
necessary-
1st. That the fire shall be free to pass partly into the movable sole or bed plate
in order that there may be no sensible difference between the degree of baking of
that portion of the products which is placed directly on this sole and the part
above the same.
2nd. That the gallery or annular working chamber of the furnace cannot be-
come deformed under the action of expansion, as otherwise the movable sole could
no longer work in its groove.
3rd. That at any moment the temperature in the chamber may be modified or
regulated and the nature of the flame also be modified to render it, according to
requirements, an oxidizing or a reducing one.
4th. That at any moment, and without modifying the internal working of the
furnace, the temperature of the walls of the furnace may be regulated, which walls
have a tendency as a rule to accumulate too much heat. This tendency rapidly
destroys the normal working of the furnace, principally in the part of the gallery
serving for the progressive cooling.
5th. That the metal part of the movable sole or bed shall be well insulated
from the heat radiating from the working chamber in order to prevent its rapid
destruction or deformation.
6th. That chambers for charging and discharging be employed in which the pro-
ducts are progressively equalized in temperature with the medium into which
they are about to enter.'
The continuous ceramic furnace with heated movable sole, which forms the
object of my present invention, realizes these different desiderata in the following
manner:
1st. The flames can penetrate and circulate under the open or perforated part
of the movable sole, and thus bring this lower part of the working chamber to the
same temperature as the space above it, which is an indispensable condition for
producing uniform baking.
2nd. The deformation of the furnace by expansion is avoided by forming the
walls of the working chamber of the furnace in two concentric rings. The exter-
nal ring, which is the larger one, is easy to protect, because its thrust or the direc-
tion of its deformation is directed outwardly, but the internal ring tends to be
deformed towards the interior of the working chamber where it is impossible to

page_text: employ buttresses or strengthening pieces and therefore this deformation must be
prevented by the following special arrangement. The walls of the furnace are
formed of hollow pieces shaped in such a way that in the horizontal and vertical
joints the pieces always, fit one into another with sufficient.play to allow of free
expansion. The pieces of the lower part of the wall are embedded in a trellis
girder which connects the piles supporting the walls of the furnace, the course of
pieces next above is stayed and held in place by overlapping pieces which form
with a key stone the ceiling or roof of the working chamber or gallery, and a
middle course is held between the upper and lower courses to form a solid whole.
With this method of arrangement sufficient play may be left between the joints to
allow of expansion taking place freely, and to thus avoid any diminishing of the
free space in the working chamber or gallery in which the movable sole circu-
lates with its load.
3. The regulation of the temperature of the furnace and of the composition
of the flame.
In order to regulate the temperature in the furnace the supply of gas to the
burners may be instantanously increased or diminished by adjusting admission
valves, and the supply of air necessary for combustion be regulated by the draught
of the chimney and by the adjustment of air admission openings formed in the
door which closes the working chamber at the side from which the finished,
When the source of heat consists
baked, and cooled products are withdrawn.
of one or more ordinary furnaces, the working thereof must be accelerated or
diminished by the draught alone.
In order to regulate the composition of the flame the manipulation is the same.
When it is desired to work with a reducing flame an excess of gas is employed by
opening the admission valves and partially closing the air inlets. In order to
work with an oxidizing flame, the quantity of gas is on the contrary diminished
by partially closing the admission valves, and the quantity of air is increased
either by acting on the draught or by opening more widely the air inlets. It is
evident that this adjustment will always be easier where a blast gasogen is
employed than with any other furnace.
4. The regulation of the heat radiating from the walls.
At the end of a certain period of working it may become necessary to counteract
the too great radiation of heat from the masonry towards the interior of the work-
ing chamber. In fact after a certain period of working, this masonry will have
absorbed a large quantity of heat which may become deleterious principally in the
part used for the progressive cooling. In order to preserve the advantages of an
even and continuous working of this system of furnace, and to allow of the cool-
ing of the products being properly effected, the temperature of radiation must be
maintained within certain limits. Thus (in the cooling zone) all the heat im
parted to the masonry by the products during the process of cooling must, as far
as possible, be removed from said masonry in order that too much air need no
be sent through the working chamber from the air admission openings, thu
avoiding breakage of the products by too sudden or too direct a cooling.
In order to avoid this drawback, I cause fresh air to circulate in the hollow
walls of the furnace. Air is introduced by means of adjustable external opening
and draught chimneys, which are also adjustable, and allow of as much air as i
necessary being passed into the walls, in order to deprive them of the excess o
heat which they may have accumulated. The hot air which is obtained may be
utilized in drying apparatuses or for any other suitable industrial application.
In the zone of preparation it may happen that, in causing the flames to circu
late to the end of the working chamber, in order to allow them to escape to th
chimney the heating of the products is too sudden, and not sufficiently gradual
particularly after a certain period of working. In this case the chimney regis
ters are closed and other registers opened, so that the hot gas quits the workin
chamber at another point and reaches the chimney by passing through the hollo
walls. The said part is then no longer heated directly by the flames, but simpl

page_text: by radiation, which may be very useful in the case of certain products which break
very easily when exposed to heat.
5th. Isolation of the metallic part of the movable sole (bed) of the furnace.
The radiation from the interior of the working chamber cannot act directly on
the sand bath or luting (which closes the bottom of the working chamber), nor on
the metallic part which carries the fireclay parts of the moveable sole. In fact the
projections or shoulders, which are formed on the lower course of the wall and on
the movable sole, break this radiation.
The under part of the movable sole is entirely in the open air, which protects
the metallic part against too great a heating by conductibility.
This special arrangement has, in addition, the very great advantage of enabling
all the parts of the sole to be inspected and visited at will. The parts formed of
fireclay, constituting the roof of the working chamber, are also easily removed,
in case inspection of the interior of the working chamber becomes necessary,
without its being necessary to entirely extinguish the furnace. These parts as
well as the walls of the working chamber are provided with a certain number of
peep holes allowing the baking to be inspected. A sand bath is carried by the
inovable sole and revolves with it, in order that the same portion of this part may
not be constantly near the zone of high temperature and thus its preservation is
ensured.
The right is reserved of varying the forms, dimensions, proportions and acces-
scry parts and of employing in their construction any materials which may be
deemed suitable.
Dated thin 7th dor of August 1896
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
Improvements in Continuous Ceramic Furnaces with Heated
Movable Soles.
I, HENRI STURM of 16 Rue Drouot, Paris in the Republic of France, Engineer,
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:-
Efforts have already been made to produce continuous ceramic furnaces with
movable floors or soles, but none of such furnaces have as yet come into practical
use because they were not rationally designed as regards details of construction
which in this arrangement, more than in any other, are of essential importance.
In order that a furnace of this kind may be practicable and effective it is
necessary,
1st. That the fire shall be free to pass partly into the movable sole or bed plate
in order that there may be no sensible difference between the degree of baking of
that portion of the products which is placed directly on this sole and the part
above the same;
2nd. That the gallery or annular working chamber of the furnace cannot be-
come deformed under the action of expansion, as otherwise the movable sole could
no longer work in its groove;
3rd. That at any moment the temperature in the chamber may be modified or
regulated and the nature of the flame also be modified to render it, according to
requirements, an oxidising or a reducing one;
4th. That at any moment, and without modifying the internal working of the
furnace, the temperature of the walls of the furnace may be regulated, which walls

page_text: destroys the normal working of the furnace, principally in the part of the gallery
serving for the progressive cooling;
'
5th. That the metal part of the movable sole or bed shall be well insulated
from the heat radiating from the working chamber in order to prevent its rapid
destruction or deformation;
6th. That chambers for charging and discharging be employed in which the
pro-
ducts are progressively equalised in temperature with the medium into which
they are about to enter.
The invention will be described with reference to the accompanying drawings,
in which,
Figure 1 is a view in sectional elevation on the line A B C of Figure 2;
Figure 2, a plan view;
Figure 3, a sectional elevation on the line D B E of Figure 2; and
: .
Figure 4 a sectional elevation on the line F B G of Figure 2 of the continuous
ceramic furnace with heated movable sole which forms the object of my present
invention and which realises the aforesaid different disiderata in the following
manner:-
1st. The flames can penetrate and circulate under the open or
of the movable sole as shown by the arrows f f, Figure 1, and thus bring this
perforated part
lower part of the working chamber to the same temperature as the space above it,
which is an indispensable condition for producing uniform baking;
2nd. The deformation of the furnace by expansion is avoided by forming the
walls of the working chamber of the furnace in two concentric rings. The external
ring, which is the larger one, is easy to protect because its thrust or the direc-
tion of its deformation is directed outwardly, but the internal ring.tends to be
deformed towards the interior of the working chamber where it is impossible to
employ buttresses or strengthening pieces and therefore this deformation must be
prevented by the following special arrangement. The walls of the furnace, as
shown at M, Figure 2, and also in Figures 3 and 4, are formed of hollow pieces
shaped in such a way that in the horizontal and vertical joints the pieces always
fit one into another with sufficient play to allow of free expansion. The pieces a,
Figure 4, of the lower part of the wall are embedded in a trellis girder which
connects the piles supporting the walls of the furnace, the course of pieces & next
above is stayed and held in place by overlapping pieces C which form with a key
stone X the ceiling or roof of the working chamber or gallery and a middle course d
is held between the upper and lower courses a and b to form a solid whole. With
this method of arrangement sufficient play may be left between the joints to allow
of expansion taking place freely, and to thus avoid any diminishing of the free
space in the working chamber or gallery in which the movable sole circulates
with its load;
3rd. The regulation of the temperature of the furnace and of the composition
of the flame.
In order to regulate the temperature in the furnace the supply of gas to the
burners may be instantanously increased or diminished by adjusting admission
valves V, Figure 1, and the supply of air necessary for combustion be regulated
by the draught of the chimney and by the adjustment of air admission openings a',
Figure 2, formed in the, door which closes the working chamber at the side
from which the finished, baked, and cooled products are withdrawn. When the
source of heat consists of one or more ordinary furnaces, the working thereof must
te accelerated or diminished by the draught alone.
In order to regulate the composition of the flame the manipulation is the same.
When it is desired to work with a reducing flame an excess of gas is employed by
opening the admission valves V and partially closing the air inlets a¹. In order
to work with an oxidising flame, the quantity of gas is, on the contrary, diminished
by partially closing the admission valves and the quantity of air is increased
either by acting on the draught or by opening more widely the air inlets a' It is
T

page_text: evident that this adjustment will always be easier where a blast gasogen, is
employed than with any other furnace;
4th. The regulation of the heat radiating from the walls.
At the end of a certain period of working it may become necessary to counteract
the too great radiation of heat from the masonry towards the interior of the work-
ing chamber. In fact after a certain period of working, this masonry will have
absorbed a large quantity of heat which may become deleterious, principally in
the part R used for the progressive cooling. In order to preserve the advantages
of an even and continuous working of this system of furnace, and to allow of the
cooling of the products being properly effected, the temperature of radiation must
be maintained within certain limits. Thus (in the cooling zone) all the heat im-
parted to the masonry by the products during the process of cooling must, as far
as possible, be removed from said masonry in order that too much air need not be
sent through the working chamber from the air admission openings a', thus avoiding
breakage of the products by too sudden or too direct a cooling.
In order to avoid this drawback I cause fresh air to circulate in the hollow
walls of the furnace. Air is introduced by means of adjustable external openings b
and draught chimneys y (Figure 2) which are also adjustable, allow of as much
air as. is necessary being passed into the walls, in order to deprive them of the
excess of heat which they may have accumulated. The hot air which is obtained
may be utilised in drying apparatuses or for any other suitable industrial
application.
In the zone of preparation P it may happen that, in causing the flames to circu-
late to the end of the working chamber, in order to allow them to escape to the
chimney at C, the heating of the products is too sudden, and not sufficiently
gradual, particularly after a certain period of working. In this case the chimney
registers are closed and other registers r opened, so that the hot gas quits the
working chamber at another point m and reaches the chimney H by passing
through the hollow walls. The part P is then no longer heated directly by the
flames, but simply by radiation, which may be very useful in the case of certain
products which break very easily when exposed to heat;
5th. Isolation of the metallic part of the movable sole (bed) of the furnace.
The radiation from the interior of the working chamber cannot act directly on
the sand bath or luting (which closes the bottom of the working chamber) nor on
the metallic part which carries the fireclay parts of the movable sole, see Figures 1,
3 and 4. In fact the projections or shoulders which are formed on the
lower course a of the wall and on the movable sole, break this radiation.
The under part of the movable sole is entirely in the open air, which protects
the metallic part against too great a heating by conductibility.
This special arrangement has, in addition, the very great advantage of enabling
all the parts of the sole to be inspected and visited at will. The parts X formed
of fireclay constituting the roof of the working chamber are also easily removed
in case inspection of the interior of the working chamber becomes necessary,
without its being necessary to entirely extinguish the furnace. These parts X as
well as the walls of the working chamber are provided with a certain number of
peep holes Z allowing the baking to be inspected. A sand bath is carried by the
movable sole and revolves with it, in order that the same portion of this part may
not be constantly near the zone of high temperature and thus its preservation is
ensured.
The right is reserved of varying the forms, dimensions, proportions and acces-
sory parts and of employing in their construction any materials which may be
deemed suitable.
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:-
A continuous ceramic furnace characterised by the combination of the follow-
ing parts:-

page_text: 1st. A hollow movable sole permitting the products of combustion to pass
through it in order to maintain its temperature at the same degree as the furnace
walls;
2nd. Vertical walls formed by means of shaped hollow pieces fitting one in
another with sufficient play to allow of their free expansion;
3rd. An arrangement of suitable valves allowing the composition of the flame,
the supply of external air and the internal temperature of the different zones of
the furnace to be regulated at will;
4th. The special shoulder or projecting form given to the furnace walls for pre-
venting radiation to the exterior of the working chamber so as to avoid the
destruction of the metallic part of the movable sole;
5th. The arrangement of charging and discharging chambers forming chambers
in which the products are successively brought to an equal temperature with the
environment into which they are about to enter;
Substantially as hereinbefore described and shown as an example in the
accompanying drawings.
1007
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.