Improvements in and relating to Furnaces for Burning Bricks and the like.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Furnaces for Burning Bricks and
the like.
I, LUIGI TREVISAN, of Villaverla, in the Kingdom of Italy, 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 :-
My invention relates to furnaces wherein the burning of bricks and the like is
continuously effected by the combustion of the gas which is generated by the
distillation of the coal contained in retorts placed in the interior of the furnace in
order to obtain coke as a by product of great value.
In the arrangement heretofore employed the retorts are placed horizontally upon
the plane of the furnace.
This arrangement is represented in Figures 1 to 2 of the accompanying drawing,
Figure 1 being a plan and Figure 2 a vertical section of the same.
The interior of a compartment or section of any kind of continuously acting
furnace is divided, and the retorts a, a, a are built of ordinary bricks, or preferably
fire bricks, a free space or flue being left between the walls of two neighboring
retorts for enabling the flames coming from the preceding compartments to surround
and heat them. These retorts have a capacity in proportion to the capacity of
the compartment and to the quantity of coal necessary for burning the material bb
placed in the furnace.
In proportion as the burnt material is removed from a compartment of the furnace
the retorts are charged with coal which is covered with a layer of argillaceous earth,
sand or other suitable material. The compartment is charged with the material to
be burnt which bears upon the small walls of the retorts, and is then closed for
putting it in operation by means of the iron partition.
The above-described horizontal arrangement of the retorts presents various
inconveniences, the principal of which are as follows:-
:-
In
(1) The use of retorts in already existing furnaces is difficult and expensive.
fact the presence of retorts in a furnace raises the draught level of the fire-place so
that, if the level of the whole furnace is lowered in order to lower the level of the
retorts a considerable expense is necessitated.
(2) Being charged with the entire weight of the material to be burnt and being
morcover exposed to a very high temperature, the walls which form the retorts
often give way, causing the material to fall and necessitating frequent repairs.
(3) The work necessary for charging the furnace is very expensive, as wheel-
barrows cannot pass upon the plane of the furnace.
(4) When the compartment is charged the heat gradually comes from the
preceding compartments, and the coal commences to develop gas which is lost by
escaping through the chimney, for the gas can burn only when the temperature
reaches a sufficiently high degree.
(5) The position occupied by the retorts does not permit. the augmentation
or diminution of the quantity of coal which they contain during the burning
operation.
(6) If during the operation a retort falls in, the coal, as there are no means at
disposal for smothering it, and as it is exposed to the flames, will continue to burn
to the end without leaving the coke which it would otherwise yield as a residuum.
For obviating the inconveniences hereinbefore enumerated I have devised the
improved arrangement in which the retorts are placed vertically upon the plane of
the furnace. This arrangement represented in Figures 3 and 4 of the accom-
panying drawing Figure 3 being a plan and Figure 4 a vertical section of
the same.
My improved arrangement can be used in any kind of continuously acting
Pin G21

page_text: furnaces without necessitating any changes provided that these furnaces have no
horizontal lateral fire-place, in which case holes in the vault of the compartment
must be opened proportionately to its capacity. The use of this arrangement does
not necessitate any change either in the mode of introducing the materials to
be burnt, or in the draught-level of the fire place. Moreover any quantity of
coal can be introduced at the moment which may appear most suitable.
While the furnace is charged with the material to be burnt the retorts are
constructed of the bricks which are to be burnt, the latter being placed in a vertical
line with the openings which in the Hoffmann furnaces serve for feeding the charcoal
to the fire. These retorts form prisms having a square base a' a' a' or a triangular
base aa" a", with a top turned towards the axis of the furnace, but any prismatic,
circular or elliptic base can be used for the same purpose. The dimensions of the
retorts depend upon the capacity of the compartment and their number upon that
of the existing holes provided for the combustion. Of course if these holes are
considered insufficient others can be opened which in any case may serve to watch
the state of the fire during the burning operation. The retorts extend up to the
vault of the compartment, and the last trunk, to a length of say from 0.20 to
0.30 metres, is formed of a single piece, which arrangement protects the retort
against any damage while the coal is introduced. Care is taken to press as much
material as possible against the sides of the retort.
Having thus been charged with material to be burnt the compartment is set in
action by lowering the iron partition. As soon as the interior of the retorts has
reached a temperature which is deemed suitable coal is introduced into the same,
and immediately covered with a layer of sand having a thickness of a few centimetres.
However the whole quantity of coal necessary for the burning should not be intro-
duced at once it is preferable to introduce less, for there is always time to add as
much as may be necessary, even while the heat of the compartment is greatest.
Under these conditions the coal which finds a very high temperature in the
retort immediately gives off gas which burns at once. Thus not only all the
products of the distillation of coal are utilized, but the operation can also be
regulated at will by introducing into the retorts the quantity of coal which during
the operation is deemed suitable for the proper burning.
When the coal, on being transformed into coke and diminished in volume, shrinks
so as to leave the side of the retorts it is necessary to add a fresh quantity of sand,
which descending in the open spaces completely surrounds the coke and prevents
ulterior combustion.
As the retorts do not give rise to expenses for repairs, being made of material
which can be utilized every time when the compartment is charged, it may be
concluded that the inconveniences hereinbefore enumerated in respect of horizontal
retorts are completely obviated by the vertical retorts which I employ.
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 :-
First. In furnaces for burning bricks and the like the arrangement of retorts
vertically upon the plane of the furnaces, the said retorts being formed of bricks
designed for the burning and having an elliptic, circular or prismatic section.
Second. The method of charging the retorts of furnaces for burning bricks and
the like after the material to be burnt has been put in its place so that the coal
may be introduced only when the retort is sufficiently hot for rapidly obtaining the
disengagement and inflammation of the gas.
Dated this 11th dox of November 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.