Improvements in Kilns or Ovens for Firing Terra-cotta and other like Materials.
Year: 1894

page_text: Date of Application, 14th N.v., 1894-Accepted, 9th Mar., 1895
COMPLETE SPECIFICATION.
Improvements in Kilns or Ovens for Firing Terra-cotta and other
like Materials.
We, CHARLES DUBOIS D'ENGHIEN, ALPHONSE DUBOIS D'ENGHIEN and
SILVAIN DUBOIS D'ENGHIEN, all of Hennuyères, in the Kingdom of Belgium,
Tile Manufacturers, 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 :—
The improvements forming the subject of the present application have very
great advantages over the means described in our Patent No. 18281".
These advantages are:-
1. Preliminary or complementary smoke drying in the kiln or oven of the
products placed therein, which gives them a very beautiful tint.
2. Considerable diminution in the cost of the kiln or oven, by reason of the
reduction in the volume of the masonry and earth works.
3. Hermetic closing of the registers by means of their horizontal position in
place of employing bell covers as indicated in the drawings accompanying
Specification No. 18281 of 1891 or vertical registers referred to in the description
accompanying these drawings.
4. Great facility given to the draught by means of the arrangement of the
conduits leading to the chimney.
Uniformity of baking indicated as the second advantage in the Specification of
the above mentioned Patent, is entirely retained although the draught only takes
place on one side of the oven or kiln.
We draw attention
1. To our two methods of preliminary or complementary smoke drying of the
products. These means of smoking are possible in our oven or kiln by reason
of the separation which exists between the charge of each chamber, as they are
not charged above the grating. These methods constitute a very important point,
the question of smoking in kilns or ovens having continuous fires, having been
the object of exceedingly numerous researches.
2. To our method of draught which is of equally great importance.
All the advantages mentioned in Patent No. 18281" are retained.
And in order that our invention may be more clearly understood and readily
carried into effect we will proceed aided by the accompanying drawings fully to
describe the same.
Figure 1 shows our kiln or oven partly in elevation, partiy in longitudinal
section on the line A B, and partly in longitudinal and transverse section on the
line C D, of Figure 3.
Figure 2 is a section on the line E F of Figure 3.
Figure 3 is partly a plan and partly a horizontal section of an oven or kiln
having continuous fires constructed according to our invention and having
16 compartments.
Figure 4 is a front view of the door of the furnace lettered as described in
Specification 18281 of 1891.

page_text: Figure 6 shows our system applied to an oven or kiln having a continuous or
intermittent fire with 6 compartments; this figure indicates our oven or kiln partly
in elevation, partly in longitudinal section on the line C D and partly in longi-
tudinal section on the line A B of Figure 9.
Figure 7 is a section on the line E F of Figure 9.
Figure 8 is a section on the line G H of Figure 9.
Figure 9 is partly a plan and partly a horizontal section of our system applied to
an oven or kiln of 6 compartments having intermittent fires.
DESCRIPTION OF THE OVEN OR KILN.
As indicated in the Specification of Patent No. 18281" the kiln or oven having
continuous fires is composed of two parallel and arched galleries, the first having
compartments marked 1, 2, 3, 4, 5, 6 and 7 and the second those marked 9, 10, 11,
12, 13, 14 and 15 united at their extremities by two circular compartments 8
and 16, which diminish gradually in width. The narrowing of the compartment 8
commences at 7 and finishes at 9 that of compartment 16 commences at 15 and
finishes at 1.
This arrangement has for its object to force the gases coming from the
compartments 7 and 15 to pass along the large interior circle of the compart-
ments 8 and 16 and to traverse the products placed throughout the whole
compartment, which would not happen if it was the same width throughout, for
the gases not meeting with any obstacles would take the shortest road against
the sides A A, Figure 3 and would not bake perfectly the products placed
against the other side.
Between each compartment is placed a grate B which receives the fuel and
under each grate is an ash pit C.
The draught openings described in the Specification of said Patent No. 18281
are dispensed with.
The draught in the present oven or kiln is effected in the following manner.
In each compartment is a masonry wall D which leaves a space E through which
the gases are introduced into a channel F formed in the exterior supporting walls
of the oven or kiln, from this channel the gases pass through an opening G, where
a horizontal register H of ordinary form is placed, into a channel 1 and from there
into the principal conduit K which leads to the chimney L. On the framework of
the register is placed a slab J to support the masonry O, Figures 1, 2 & 3.
The oven is not charged above the grate, the length of which latter therefore
forms a separation between two compartments.
Before the grate B are the entries M of the doors V of the compartments see
Figures 1, 2 and 3.
The arch of each compartment is pierced with holes N Figures 1, 2, 3 closed by
means of bell covers as indicated in the aforesaid Specification No. 18281.
As shown in the above mentioned Specification, the floor of the chambers may
be sloped.
On the side of the grates B1, B2, there are small walls Q constructed to serve as
supports for the chargement of tiles, pipes or other products which would be
difficult to arrange in the oven without this wall. For charging the oven with
products which may be made to stand without support, this wall is not used.
The operation of the oven having continuous fires, is described in our said
former Specification No. 1828191.
The only difference existing consists in the openings conducting the gases to the
principal conduit. These latter in lieu of passing through the spaces of the grates
into two openings starting from the ashpit, take the direction indicated by the
arrows H H H Figures 1 and 3.
The gases find their way through the opening E formed by the masonry D and
the side of the kiln or oven, into the channel Fat the extremity of which they
come to an opening G which can be closed at will by a register H Figure 2. placed

page_text: horizontally at this part, this register is manipulated from the exterior of the
supporting wall. Through this opening G the gases pass into the channel I which
opens into the principal conduit K communicating with the chimney L.
The new system is applicable, like that forming the subject of aforesaid Patent
No. 18281, to a furnace with intermittent fires and having two galleries. The
arrangement is the same as that we have just described.
The system is also applicable to a kiln or oven with intermittent fires and having
only one gallery as represented at Figures 6, 7, 8, 9.
The interior arrangement is the same except that there is no draught in the first
compartment, and that that of the last is effected through an opening P in the
supporting wall at the extremity of the kiln or oven.
The operation of the kilns or ovens with intermittent firing is identical with that
of a kiln or oven with continuous firing.
PRELIMINARY OR COMPLEMENTARY SMOKE DRYING OF THE PRODUCTS.
All kilns or ovens with continuous firing have the serious inconvenience of causing
on red products fired therein, and principally on bricks, very disagreeable white
marks. In consequence of the bad color of these products, they cannot be employed
for particular work.
Also tiles but principally facing bricks are still fired principally in kilns or ovens
with intermittent firing which consume an enormous quantity of fuel because it is
preferred to incur a greater expense in fuel and to have good red products.
This inconvenience we cause to disappear by our method of preliminary or
complementary smoke drying of the products.
For this purpose we use one of the two methods which we have just
described.
For each the smoking is effected of one compartment at a time.
First Method. The paper partition is placed on the front and in the interior of
each chamber that is to say at X against the perforated masonry wall if such exist
and against the first or the second row of products if there is no wall built at this
part. A small paper partition, should also be placed at the end of the opening E
in the interior of the chamber.
Suppose when the kiln or oven is in regular work, that the fire has just been
advanced to the compartment 16 and that the draught is effected through
conduit No. 1 of chamber 1, the paper partition placed on the front of chamber 2 is
burnt. In this manner the compartments 16, 1 and 2 are in communication amongst
themselves. The draught is effected as abovesaid through the conduit of chamber 1
marked with the same number. In consequence of the absence of paper separation
between the chambers 1 and 2, the products contained in chamber 2, are gradually
heated which evaporates the water which they may yet contain. The vapour arising
from this drying escapes by the chimney, following the same route as the gases
arising from compartment 1, that is to say by following in the conduit F No. I the
direction indicated by the arrow H¹.
To obtain a complete drying of the products placed in chamber No. 2, hot air is
introduced into this compartiment by means of one or of two tubes. One of the ends
of each of these tubes, is passed through an opening in the arch of one of the
compartments baked and the other end into the opening made above the grate B³.
To cause each of the tubes to open into the space existing between each
compartment, there may be two openings above the grate.
When the products of compartment 2 are sufficiently dry, those of chamber 3 are
smoked. For this purpose the register of chamber 1 is closed, that of chamber 2
is opened and the paper partition made on the front of compartment 3 is
burnt.
The gases rising from compartment 2 then follow the direction indicated by the
arrow H³, it is also by the conduit marked with the figure 2 that the steam rising
from the drying of the products placed in chamber 3 escapes. To obtain a

page_text: complete drying of these latter, hot air is caused to enter, as above described,
through the opening or openings existing in the arch above the grate marked B*.
The smoking of each compartment is effected as above described.
Second Method.-Suppose again the kiln or oven is in regular work and that
compartment 16 is being baked. Fire will be made on two grates at the same time,
one of which at B1 is very large to bake the compartment 16 and the other fire
small to complete the drying of the products placed in chamber 2 or 3.
If it is desired to dry compartment 2, the fire will be made on the grate of this
chamber, that is to say, on B2 and the draught will be effected through the conduit
the
arranged for this compartment, that is to say, through the channel No. 2, paper
being placed on the front of chamber 3. If the drying of chamber 3 is desired, the
small fire will be made in the grate of this compartment, that is to say, on B³ and
the draught will be effected by conduit No. 3, the paper being placed on the front
of chamber 4. Doors V, sec Figs. 4 and 5, are employed which are constructed
and arranged as described in our said former Specification.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The new method of draught which is effected on one side of the kiln or oven
substantially as herein shown and described.
2. The horizontal position of the register in the conduit.
3. The greatest possible facility given for the escape of the gases into the
chimney by the particular arrangement of the conduits, the chimney being,
according to our system outside the kiln or oven.
4. The preliminary or complementary smoke drying of the products in the kiln
or oven which is effected by means of one of the two methods which we have
described. It is to be remarked, that the employment of the one or the other of
these methods is only possible in consequence of the separation in the charge of
each chamber, which forms a peculiarity of our invention.
5. The improvement in kilns or ovens substantially as herein shown and described
and for the purpose stated.
Date N.
14 1001
CHARLES DUBOIS D'ENGHIEN,
ALPHONSE DUBOIS D'ENGHIEN,
SILVAIN DUBOIS D'ENGHIEN,
By Harris & Mills,
thampton Buildings, London, W.C., Agents.
CHARLES DUBOIS D'ENGHIEN,
ALPHONSE DUBOIS D'ENGHIEN,
SILVAIN DUBOIS D'ENGHIEN,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.