Improved Reverberatory Furnace.
Year: 1899

page_text: Date of Application, 8th Aug., 1899-Accepted, 6th Jan., 1900
COMPLETE SPECIFICATION.
Improved Reverberatory Furnace.
I, JOHN ARMSTRONG, of No. 46, Lombard Street, in the City and County of
London, 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:-
The object of this invention is an improved furnace for the purpose of smelting,
melting or reducing metals, ores, glass, chemicals, or other substances, more
economically and with better results than has hitherto been possible in rever-
beratory furnaces.
This furnace is a reverberatory furnace and is constructed as shewn on the
accompanying drawings, and may be constructed either double as in Figs. 1 and 2
or it may be single as in Figure 3. The double furnace is simply two single
furnaces placed end to end and for economy in firing, one fire grate is made
common to the two furnaces.
Figure 1 is a plan.
Figure 2 is a longitudinal section.
Figure 3 is the section of a single furnace, and
Figure 4 is a cross section through the fire grate.
Figure 5 is a cross section through the bed of the furnace.
This furnace consists of an iron tank constructed with plates of iron joined
together in any suitable way by means of rivets or bolts and made practically
water tight so as to avoid leakage of any materials that may be placed in it;
nis irontank is shewn on the drawings and marked at m m. This tank is braced
and stayed together with iron brickstays and is also supported by bearers z z.
The walls of the furnace are constructed in the ordinary way of constructing
furnaces by means of refractory fireclay, firebrick, chemical resisting bricks,
stone blocks or other material suitable for the substances that may be operated
upon in the furnace. The walls are built from the ground sufficiently high
to receive the iron tank as shewn. In the interior of the tank is then com-
menced the formation of the floor of the furnace hh which is laid upon a lining
of silica sand or other refractory material of a sufficient thickness to give a
firm and proper bed for the bricks and other materials. The bed is made in the
form of an inverted arch h', shown in Figure for the purpose of withstanding
an upward pressure formed by melted materials (heavier than brick) sinking
through the joints beneath the bed of the furnace, and thereby disintegrating
the bricks from their proper level and consequently damaging the bed so that it
very soon becomes useless if it is made flat. The bed is made with a slope towards
the sump at the ends marked 9 g which is also constructed and formed in section
with an inverted arch for the same purpose as just described. A retaining bridge
or wall is also formed if necessary as shewn at oo with an opening at o' o¹ which
may be closed with a block of refractory material if required. The sump is also
made with a slope on the bottom towards one side of the furnace and provided

page_text: with tapping holes in either side of the furnace. These tapping holes may be
made on different levels for the purpose of tapping off all material from the
sump of different specific gravities. These tapping holes may be constructed in
the form of syphons formed in the walls so that the lower stratum of material
may be tapped off leaving the upper layer in the furnace. The walls of the
furnace are continued above the hearth of the furnace until the springing of the
roof which is formed in the shape of an arch; at the firing end of the hearth
is the fire bridge constructed as shewn at d and hollow at 3, where the iron
tank is made to be turned up as at d to prevent leakage into the fire of the
melted materials from the hearth. At the other end of the furnace is formed
the working door marked p p, where the workmen can command a view of the
whole interior of the furnace, and where the working door may be left open
without any fear of the atmosphere being admitted to the detriment of any of the
materials that may be under treatment in the interior of the furnace. As the
draught flues are constructed on right and left of this working door as at qg,
which are regulated with proper dampers, and are connected with a chimney
shaft, if necessary, this working door may be closed with a door.
The fire grate is constructed either at one end as in the single furnace, Figure 3,
or as in the double furnace Figures 1 and 2. The single furnace may have its
bars fixed in one single row and inclined at an angle to the bridge so that the
firebars may be exposed to the end of the furnace which in this case would be
open at the end; or the firebars may be placed as shewn at Figure 4 hung from
each side on bearers t², 2, of the furnace, and each bar crossed at the lower end
upon a bearer f. These bearers may be made hollow in the form of tubes and
perforated for the purpose of conveying water or steam under the grate, the
central bearer f is made movable if necessary, and may be pulled out so that the
fire may be dropped quite out, and all the bars will then hang down from the
side bearers, as they are formed with a hooked end for that purpose.
The object
of crossing the bars is for the purpose of keeping them the proper distance
apart which is a great consideration in all furnaces, and as the ends project over
the middle bearer f they are accessible to the workmen to lift or shake; so that
the fire is easier kept in a proper condition. The bars also may be made hollow,
of tube to convey water or steam. The side walls are in this part of the furnace
completely taken away as shewn in Figure 4 at a¹ a' and the upper portion of the
wall is carried on bearers a², a² so that the workman can manipulate the bottom of
the furnace and keep the walls d, d of the furnace as well as the bars quite free
from accretion of clinker, without disturbing the fire, and by lifting up slightly
one of the bars, the clinker may be dropped with a very considerable saving of
labour over the present system of ordinary fire grates. There is an inspection
hole at n closed with a door; the fuel is fed in at (a) through the hopper W, which
is closed with a tight-fitting lid to keep in the gas that may be formed. This
furnace is constructed as a gas producing furnace, and may be used as a pure
reducing furnace simply where the presence of free oxygen or atmospheric air
or carbonic acid would be injurious; or by an arrangement of placing air tubes in
the wall of the bridge as shown at d, d, it can be used as an ordinary reverberatory
furnace where the carbonic mon-oxide will be burned in the passage over the
bridge d. Should, however, the presence of the above gases or air be injurious,
then the furnace is constructed as shewn without the air holes, when a perfect
atmosphere of carbon mon-oxide will be produced.
In order to introduce materials of a light or dusty nature into the furnace as
well as for the purpose of effectually excluding the atmospheric air, I place tubes
or other forms of such like apertures in the roof or sides of the furnace as is shewn
at b, b, and made of any suitable material such as fireclay, and which are so con-
structed that the materials are introduced into the bed of the furnace without the
slightest trouble or dust. These apertures or tubes may be provided with
hoppers or close fitting lids w. A tray for water may be placed, or a well may be
sunk at Y in order to receive the ash from the grate.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. In a reverberatory furnace, means for introducing light or pulverulent or
granular materials therein without admission of air consisting of tubes passing
down beneath the surface of the charge, substantially as described.
2. In a reverberatory furnace, a grate having fire bars supported alternately at
each side, and on a central longitudinal bar or support and preferably sloping
downwards to the said central support so arranged that individual bars can be
raised or lowered, or the entire set dropped down, substantially as described.
3. The combination of parts forming the improved reverberatory furnace, con-
structed and operating substantially as described with reference to the accom-
panying drawings.
Tlated this 8th day of Juust 1900
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.