Improvements in Cement Kilns.
Year: 1893

page_text: Date of Application, 13th Oct., 1893
Complete Specification Left, 16th June, 1894-Accepted, 8th Sept., 1894
PROVISIONAL SF ECIFICATION.
[Communicated from abroad by LOUIS ERNEST ALBERT LAVOCAT and
EDOUARD LOUIS CANDLOT, both of 18, Rue d'Edimbourg, Paris, France,
Engineers.]
Improvements in Cement Kilns.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in cement kilns, and has for its object
the utilization of the waste heat of a perpetual kiln, for Portland cement, for
drying pastes, whether liquid or pulpy, or moulded into bricks or blocks. This
result is obtained by means of a continuously fired kiln so constructed that the
burning can be alternated with the manipulation of the materials to be burned.
A peculiarity of the invention consists in the mode of charging, which is effected,
without lateral door, through a circular opening formed in the vaulting or arch of
the furnace, and which opening is provided with an iron cover having formed
therein a number of holes through which poking or stirring is effected. For this
purpose also, lateral openings or apertures are formed in the casing of the furnace.
The vaulting of the furnace extends to the drying chambers, and its intrados
is at a level with the arrival and charging platform for the paste, either pulpy or
moulded into bricks.
An inclined plane rises up to the firebridge of the two drying chambers which
are separated from each other by a wall, serving also as an abutment to the vaultings
which cover the two drying chambers. These vaultings extend forward by an
amount equal to the thickness of the wall which serves to close them on the side
of the furnace. The walls and the abutment of the drying chambers form two
distinct passages which are simultaneously controlled by dampers arranged at the
front and back of the chambers, the back dampers being in communication with the
chimney or shaft. Suitable doors are provided, some of which serve as an entrance
for the pulpy paste, or material moulded into bricks, and others for the exit of the
dried material.
The furnace being fired, and the dampers of one drying chamber being closed,
the products of combustion pass through the other drying chamber, the dampers
of which are open.
When the paste in the latter chamber is dry, the dampers of
that chamber are closed, and those of the other chamber opened, and so on, so that
drying may be carried on in a continuous manner. All the doors may be opened
simultaneously to produce a draft for cooling the drying chambers. The top of the
drying chambers may also serve for drying the paste. Flues may be arranged in
the flank of the vaultings to facilitate this drying.
The above described arrangement is applicable to the drying of liquid paste.
In this case the doors are closed and the paste is run into the drying chamber
through a manhole.
What has just been stated for a perpetual kiln, constructed specially for the
utilisation of the waste heat, is applicable to kilns known as English kilns ("Fours
Anglais ") furnished with drying chambers. These kilos may be readily converted
into perpetual kilns with double drying chamber by the construction of a wall
dividing the lower drying chamber into two equal parts. The drying chamber of
the adjacent kiln can also be utilised as a second drying chamber, this kiln not then
serving for the burning of cement.

page_text: Instead of constructing the drying chamber as above described, the height of the
gas passages can be reduced, and instead of distributing the paste in the drying
chamber by barrows or trolleys entering the doors at one end and leaving by those
at the other end, the drying chamber may consist of two or more flues covered with
iron plates which can be raised to withdraw the dry paste, the charging being
effected by means of shovels.
The height of the flue may also be still further reduced, till its size is merely that
necessary for the passage of the gases, and only the upper part of the plates be
utilised for drying purposes.
1000
COMPLETE SPECIFICATION.
Improvements in Cement Kilns.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, 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, reference being had to
the accompanying drawings and to the letters and figures marked thereon, that is
to say:
This invention relates to improvements in cement kilns, and has for its object
the utilization of the waste heat in a perpetual Portland cement kiln for drying
pastes, whether liquid or pulpy, or moulded into bricks or blocks. This result is
obtained by means of a continuously fired kiln so constructed that the burning can
be alternated with the manipulation of the materials to be burned.
And in order that the invention may be readily understood I have shown a kiln of
this system in the annexed drawings, in which :-
Fig. 1 is a section of the kiln taken on the line A, B, C, D of Fig. 2.
Fig. 2 is a horizontal section, and
Fig. 3 is a transverse section taken on the line E, F of Fig. 2.
A peculiarity of the invention consists in the mode of charging, which is effected,
without a lateral door, through a circular opening 1 formed in the vaulting or
arch 2 which covers the furnace. This opening, which is closed by an iron cover,
is co-axial with the furnace. On its periphery are holes 3, 3, through which poking
or stirring can be effected. For this purpose also, lateral openings 4, 4, or apertures
are formed in the casing of the furnace.
The vaulting or arch 2 of the furnace ceases at the vertical plane E F. Its
intrados is at a level with the arriving and charging platform 5, for the pulpy
paste, or paste moulded into bricks.
An inclined plane 6 rises up to the fire-bridge of the two drying chambers 7 and 8,
which are separated from each other by a wall 9, which serves as an abutment to
the two vaultings or arches which cover the two drying chambers. The vaultings
or arches extend beyond the vertical plane E, F, by the thickness of the wall 10,
which serves to close them on the side next the furnace.
The walls 11 and 12, and the abutment 9, of the drying chambers, form two
distinct passages 13 and 14 (Figs. 2 and 3) which are controlled simultaneously by
the dampers 15, 16, (Fig. 1) or the dampers 17, 18 (Fig. 2), placed at front and at
back of the drying chambers 7 and 8, the back dampers being in communication
with the chimney or shaft by the passage 19.
The doors 20, 21, serve as an entrance for the pulpy paste, or paste moulded
into bricks; the doors 22, 23 as an exit for the dry paste.
The kiln being fired, and the dampers 16, 18 of the drying chamber 8 being
closed, the fire passes through the drying chamber 7, the dampers 15, 17 of which
are open.
When the paste in the drying chamber 7 is dry, the dampers 15, 17 are

page_text: closed and the dampers 16, 18, are opened, and so on. A continuous drying can be
obtained in this manner. The doors 20 and 22, or 21 and 23 being opened simul-
taneously, produce a draft which cools the corresponding drying chamber.
The top of the drying chamber may also serve for drying the paste. Flues.
arranged in the flank of the vaults or arches facilitate this drying.
The above described arrangement is applicable to the drying of a liquid paste..
In this case, the doors 20, 21, 22, 23 are closed, and the paste is run into the
drying chambers through a hole 24 (Fig. 1).
That which has just been stated for a perpetual kiln constructed specially for
the utilization of the waste heat, is applicable to kilns known as English kilns
(Fours Anglais ") furnished with drying chambers. These English kilns may be
readily converted into perpetual kilns with double drying chamber by the con-
struction of a wall dividing the lower drying chamber into two equal parts. The
drying chamber of the adjacent kiln can also be utilized as a second drying
chamber, this kiln then not serving for the burning of cement.
Instead of constructing the drying chamber as above described, the height of
the gas passages 25 (Fig. 1) can be reduced, and instead of distributing the paste
in the drying chamber by means of barrows or trolleys entering at 20 or 21 and
leaving at 22 or 23, the drying chamber may consist of two or more flues covered
with iron plates which can be raised to withdraw the dry paste, the charging being
effected by means of shovels.
The height of the flue may also be still further reduced till its size is only that
necessary for the passage of the gases, and only the upper part of the plates may
be utilized for drying purposes.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :
1. The construction of cement kilns in such a manner that they are capable of
acting in a continuous manner and of sending their products alternately to two
twin drying chambers whereby the materials may be dried in one chamber while
charging is effected in the other, substantially as described.
2. In cement kilns, the arrangement of drying chambers in such a manner that
the material can be introduced in barrows, and the extrados of the vaultings or
arches can be used for drying purposes, substantially as described.
3. The construction of cement kilns in which the alternate drying chambers are
of reduced height and can be charged by means of shovels, the covering plates
being utilized for purposes of drying, as described.
4. The construction of cement kilns in which the flues are reduced to the size
necessary for the passage of the gases, and the upper walls, or the covers, are
utilized as alternate dryers, substantially as described.
5. In the construction of cement kilns known as English kilns, providing the
same with alternate drying chambers, by suitably partitioning the drying chamber,
substantially as described.
6. The improvements in cement kilns substantially as herein before described and
as shown with reference to the accompanying drawings.
Dated this 16th day of June 1894