Improvements in Kilns or Ovens for Firing Terra-cotta and other like Materials.
Year: 1895

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Date of Application; 20th Apr., 1895-Accepted, 13th July, 1895
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Improvements in Kilns or Ovens for Firing Terra-cotta and other
like Materials.
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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 our invention and in what
manner the same is to be performed to be particularly described, and ascertained
in and by the following statement::-
1
The improvements forming the subject of the present invention are illustrated in
the accompanying drawings and have great advantages over the means described
in Specification No. 18281 of the year 1891 and in Specification No. 22008 of the
year 1894.
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These advantages' are:
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1. Diminution in cost of the furnace by the reduction in volume of the masonry
and earthworks.
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2. Increase of the draft consequent on the position between the two galleries, and
therefore in a place continually hot, either of the smoke chamber necessary for the
draft as indicated by Figures 1 to 6 or of the principal conduit leading to the
chimney as represented in the drawings Figures 7 to 12.
3. Division of the circular (end) compartment which is contracted towards its
outlet, into two small firing or baking chambers, or even into three; if certain
circumstances necessitate the wide separation of the two galleries, in which case
the circular compartment would become too long to form only two divisionary
chambers.
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The establishment of these two or three compartments is necessitated by the
increase consequent on the existence of a sinoke chamber, of the distance separating
the two galleries of the kiln or oven.
4: Substitution for the wall D forming the opening E shown in Figures: 2 and 8
of the drawings accompanying our application No. 22008 of the year 1894 by a
small vertical wall D and a cover D' of refractory material.
"
5: Division of the door of the furnace into two parts as shown at Figures 11
and 12. This division constitutes a great advantage as only one part is opened at a
'time, whereby only half of the former amount of cold air is introduced into the kiln
or oven at the moment when the fire is charged or attended to.
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"All the advantages indicated in the Specification hereinbefore referred to are
retained.
....
We desire to draw attention.
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1. To our different modes of making the draft, which may each be required,
according to the products to be baked or fired and the site at disposal. for
constructing the kiln or oven.
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2. To the division of the circular (end) compartment into two or three small
baking or firing chambers in the arrangement shown at Figures 1 to 6.
3. To the division of the furnace door into two parts:
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"In order that our invention may be clearly understood we will now describe it
aided by the accompanying drawings in which:
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Figure 1 is partly a plan and partly a horizontal 'section of an oven or kiln with
continuous fires of our system with smoke chamber of 16-compartments numbered
from 1 to 16; this figure indicates the shaft made in three different ways.

page_text: Figure 2-18-partly an elevation, partly a vertical fongitudinal section through the
centre of the areh and partly a vertical, longitudinal section through the centre of
the kiln or oven,
Figures 3, 4, 5 and 6 are vertical cross sections drawn respectively on the
lines G. H, A B, C D, and E F of Figure 1.
Figure 7 is partly a plan and partly, a horizontali section of a kiln, or oven of our
system having continuous fires and 14 compartments numbered 1 to 14 with draft
conduit at the centre. This view represents the draft made in two different
ways.
Figure 8 represents this same Kiln or oven partly in elevation, partly in vertical
longitudinal section through the centre of the arch and partly in vertical longi-
tudinal section through the centre of the oven or kiln.
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Figures 9 and 10 are vertical 'cross sections drawn respectively on the lines A B,
CD of Fig. 7
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Figure 11 is a front view of the furnace door divided into two parts.
Figure 12 is a cross section of this door:
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We will now describe the improvements applied to our kiln or oven forming the
subject of the Specifications herein before referred.to.
Figures 1 to 6 all indicate the employment of a smoke chamber marked a,which,
being located in the division between the two galleries, is always heated,, thereby
considerably augmenting the draft. From this chamber the gases pass to, the
chimney through the channel c which communicates with, the above, mentioned
chamber by the opening b see Figures, and 6...
The draft through the smoke chamber can be effected by the aid of three different
means which we will now describe...
I.
1st Apant of the gases arriving fin, the space which separates two compartments
where there is a constant draft, passes into the ash pit, by following the direction of
the arrow g. Figure 3, passing therefore through, the opening e, in front of which
is placed an iron plate from the ash pit the gases pass, through, the conduit h
into theismoke chamber a see Figures and 3, Avalye operated from the top, of
the kiln or oven as shown in the drawings serves to regulate the draft...
!
According to the manner above described, the draft is effected from the exterior
side of the oven or kiln, which for baking or firing certain products is preferable.
To effect the draft as above indicated, it is necessary,jas above mentioned; to
have an iron plate to plane before the opening through which the fuel is thrown on to
the grate. When this plate is removed a small quantity of cold air is introduced into
the kiln or oven.. This does not present any inconvenience, in the baking or firing
of certain products, but, for other very delicate products cannot very well be used.
In this latter case the draft is effected, by the aid of one of the two ways we are
about to describe, necording as the products to be, baked, on, fired' require that the
draft be made from the one side or the other of the gallery..
2nd. The draft illustrated in Fig. 4 is made through the small, conduit J formed
by the wall D and a slab of refractory material, D, see, Figures 1, and 14, arranged
in each compartment. From this channel the gases, pass, through the hole, Kinto
the channel M which conducts them into the smoke chamber a.
Their admission into it is regulated by a similar valve to that above mentioned.
3rd: The draft illustrated by Fig. 5, is effected by the conduit N Figures, I and 5
which conducts the gases into the smoke chamber a. A similar valve to that
above mentioned is also here used to regulate the draft.
As represented at Figures 1 to 6 and as above explained, consequent on the
existence of the smoke chamber a the distance separating the two galleries, is
sufficiently great. This causes the length of the eircular (end) compartments to
be greatly increased and lit would therefore be impossible to properly, bake.or jfire
from the grate O products placed at P.To remedy this inconvenience, we divide
the circular (end compartments each into two or three,small chambers by a grate R
placed in front of a doorway Swhich as in the other, compartments can be used
for the processes of charging and attending to the, fire.
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'The compartment' 15 has no draft conduit arranged specially for it, as, like the
compartment 16. it is very short in consequence of the reduction to its minimum of
the distance separating the two galleries of the kiln or oven. In this case the
draft and the smoking are effected for the chambers 15 and 116 as though they
formed only a single compartment, the grate R having simply for its object to
enable the contents of the compartment to be baked or fired quite to its end. But
If the distance separating the two galleries is sufficiently large, the chainbers 15
and 16 will be longer. In this case a draft conduit is arranged for each of these,
'as for the rectangular compartments, and like these the smoking is effected
separately for each chamber. It is also the same when the distance separating the
two galleries
Kochambers.
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ments into the very large, it is necessary to divide the circular (end), compart-
baking or firing
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T For the smoke chamber, system above described, it is necessary to share about
at the least one metre'more space between the two galleries,ithan for the central
condult draft which we are about to describe further on; further it requires armuch
larger space at the end of the furnace at T, in order that the attendant-mayibe able
to throw the fuel upon the grate R
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In case there is not sufficient ground on which to build a kiln or oven with a.
smoke chamber within the space which separates the two galleries, some with ta.
central conduit can be constructed below the separating wall of the two galleries,
as shown at Figures 7 to 10 if the thickness of the wali is sufficient for the
establishment of the channel in question. In the contrary case, draft circuits are
constructed on the exterior as indicated in Specification No. 22008 which
permits of reducing to the extreme minimum the distance separating the two
galleries.
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7.
In Figure 9 is the same small conduit Jas'that above described. The gases are
introduced by this channel into that marked see Figures 7 and 9 and from there
into the conduite which conducts them to the channel y constructed beneath othe
separating wall of the two galleries. The draft is regulated by a register z
manipulated from 'outside the supporting wall and arranged horizontally above the
end of the conduit x. We would refer for the description of this register to
Specification No. 22008 herein before 'referred to."
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To effect the draft as above described, it is necessary to erest masonry represented'
by the wall D and the cover' D'
1'.
In cases where there is no inconvenience in admitting a small quantity of cold
air into the kiln or oven at the moment of removing the iron plate herein before
referred to, we, in order to
to obviate this small construction D D effect the draft.
in the manner shown at Figures 7 and 10, which we will now describe! In plade
of causing the conduit to start from the interior of the kiln or oven, it starts from
the exterior, in the door way, as shown at Figures 7 to 10 and the following course
is adopted.
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P
The iron plate being placed as shown in the drawing see Fig. 10, the gases
take the direction indicated by
by the arrow g, enter the channel which conducts
them into the opening b thence they pass through the conduite into the central
channel y
The same register as that indicated at Fig. 9. is placed at the end of the channel.
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and serves to regulate the draft.
....-9. 1.3.4
1.
have just described, are
The different ways of effecting the having either one torstwo
applicable to ovens, or kilns having
galleries.
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the furnace divide two parts A and Battached totthe
Fig. 11 shows the
framing Fb hinges G₁. Al
by
Carried by the upper part serves to
operate it. The lower part has no handle as it requires very seldom ato. be
opened..
:
2.3 1
The door is held in position by two small angle iron attachments DiD fixed to
the bar E which latter has returned ends fixed in the walls. Each of the two

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parts of the door is divided into panels which are lined on the inside with refractory
material to protect the sheet iron from the fire..
:
parts of
Fig. 12 is a vertical section of the door, shown at Fig. 11. The cross bar N
shown in this figurer and fixed to the frame F, serves to divide the two p
the door. A small plate S attached to the framing F serves to hold either or
both of the 'two parts bermetically, closed.
For this purpose, this plate is formed with two holes into each of which an iron
bolt is placed.
To throw the fuel on to the grate, the upper part of the door just described' is
opened, the lower part remaining closed: When the fire has to be cleaned, it is
the latter which is opened and the upper part remains closed.
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In the way we have above described, a half only of the door is open at once,
which causes the quantity of cold air, which enters the kiln or oven at the moment
of-charging or cleaning the fire to be reduced to its minimum..
The working of the kiln or oven with continuous firing takes place in the manner
we will now explain. We coramence by building a temporary wall at P at the end
of the circular part. A wall is then built in the first doorway or entrance, leaving
at the bottom of this wall an opening in front of which is placed, to enable the
fuel to be thrown into the furnace, the iron door represented at Figs. 4 and 5 of
the Patent No: 18281 bereinbefore referred to or that shown at Figs. 11 and 12 of
the drawings accompanying this Specification. The charging of the first chamber
is then effected and, when this is finished its doorway is closed like the former one,
taking care to leave at the bottom the opening to enable the fuel to be thrown into
the furnace. This opening can be, provisionally closed by means of bricks or one
of the doors of which we have above spoken can be placed in front of it if it is not
necessary to use the iron plate frepresented at Figs. 3 and 10 for the draft. In
this case the end of the ashpit is closed by means of a cast iron plate. If it is
necessary to use the iron, plate fit, is placed in position in lieu of closing the
-opening in the manner described and of course the end of the ashpit is not closed.
After the first chamber has been charged, the second is charged. To this is placed,
a paper partition either on the front or on the back to prevent the introduction of
cold air into the draft conduits. The fire can be started without even having
charged the second compartment if the paper partition is placed on the front.
To do this we open the register establishing the draft at the end of the first
compartment and we light the fire upon the first grate and gradually increase its
intensity. The first compartment is heated during several hours... Its draft
register is then closed and that of the second compartment opened. The gases no
longer finding vent, burn the paper partition made in the second compartment; if
this paper does not burn sufficiently quickly, it is fired by means of a 'pole at the
end of which we place lighted, straw, or rags. This pole is introduced either by
the opening left in the wall closing the compartment or by an opening in the arch.
If the paper is placed behind the compartinent, it can be removed in lieu of being
burnt. When the charging, of the second compartment is completed, the doorway
of this latter is closed like the first, and the third compartment is then charged
in a similar manner to the charging of the second. After having established the
draft during a certain time in the second compartment, it is established in the
third and then in the fourth if desired.
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When the contents of one chamber have been completely fired, the fire' on
the grate is no longer maintained; the door is removed through which the fuel
was thrown, the opening is closed by means of bricks, and on the end of the
ashpit is placed. a cast iron, plate which is covered with sand so as, to obtain a
hermetic closure. To pass the fire to the following, compartment, it is only
necessary to remove the sheet iron plate which covers, the ashpit, to place the
door in front of the opening if it is not already tliere, and to throw fuel on the
grate This, coming into contact with red hot products, burns immediately.
In order to recuperate, the heat of the fired products, cold air is cause
1
to

page_text: enter the oven through the temporary wall P by removing a few bricks from
this wall. The size of this opening is increased little by little and it is finished
by completely demolishing this wall. When the kiln or oven is in regular work
the cold air serving for the cooling is introduced through the discharging door.
To preserve the grate bars from injury by the fire when it is necessary to
use high temperatures, they are covered with a layer of cinders.
The air should only enter the ashpit opening at the time when the fire is
being made on the grate. All the ashpit openings are therefore closed with the
exception of that in front of the grate on which the fire is being made. These
openings are closed by means of the sheet or plate f, Figs. 3 and 10, or by means
of a plate placed horizontally over the ashpit opening. At the time when the fire
is advanced to a compartment the plate f, Figs. 3 and 10, or the plate placed
horizontally over the ashpit opening, is removed to permit cold air to enter
below the grate.
The air required to serve for the cooling of the products is, when the oven
is in regular work, always introduced by the discharging door, whilst the air
required to serve for burning the fuel placed on the grate is introduced by the
ashpit opening.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. The two methods of arranging the draft substantially as herein shown and
described with respect to Figs. 3 and 4.
2. The division of the circular (end) compartment into. two or three small
baking or firing chambers substantially as herein shown and described.
3. The central conduit y constructed underneath the wall separating the two
galleries substantially as herein shown and described with respect to Figures 7
to 10.
4. The two methods of effecting the draft by the aid of the central conduit y
substantially as herein shown and described with respect to Figures 9 and 10.
5. The division of the furnace door into two parts substantially as herein
shown and described.
Dated A muil 20th 1005
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.