Improvements in Furnaces using Coal Dust or the like as Fuel.
Year: 1892

page_text: Date of Application, 2nd Sept., 1892
Complete Specification Left, 27th Apr., 1893-Accepted, 27th May, 1893
PROVISIONAL SPECIFICATION.
Improvements in Furnaces using Coal Dust or the like as Fuel.
We, CARL WEGENER and PAUL BAUMERT, both of 49 Mittel Strasse, Berlin
in the Empire of Germany, Engineers, do hereby declare the nature of this inven-
tion to be as follows:-
The present invention relates to that class of furnaces described in Letters
Patent No. 22402 dated December 22, 1891, in which coal dust or other pulverulent
fuel is consumed. The apparatus described in the Patent above referred to,
consists of a firing chamber having a cylindrical or double conical form arranged
horizontally, said firing chamber being introduced into the open end of the fire flue
of the boiler to be heated. The pulverulent fuel is, according to that Patent,
blown or forced into the ignition chamber by the aid of steam or air under pressure
or a mixture of both.
In the present invention, the firing chamber is constructed in the form of an
elbow, having its horizontal arm preferably of a conical exterior to fit tightly into
the mouth of the firing flue, whilst the pulverulent fuel is introduced at the top
of the vertical arm of the firing chamber and does not in ordinary enter the boiler
under the action of compressed air or steam under pressure, but falls into the
chamber by gravity assisted by the natural draught of the furnace chimney.
The draught of the furnace, in this case, may, however, also be increased by
means of compressed air or steam or a mixture of both, should such course appear
necessary or advisable. For this purpose, rows of holes are provided one above
the other in the vertical arm of the firing chamber, said rows each communicating
with an annular chamber. Each annular chamber communicates again with a
common air supply pipe through an adjustable regulating valve.
The pulverulent fuel is introduced into a hopper at the top of the vertical arm
of the firing chamber and is caused to fall into the same in the form of a shower
of fine dust by means of a rocking or oscillating sieve which may advantageously
be actuated by a fan, driven by the natural draught of the boiler and suitable
gearing.
The whole apparatus is advantageously formed of sheet metal plates lined with
fire bricks and may be mounted on wheels for convenience in transport.
Dated this 1st day of September 1892.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Furnaces using Coal Dust or the like as Fuel.
We, CARL WEGENER and PAUL BAUMERT, both of 49 Mittel-strasse, Berlin
in the Empire of Germany, Engineers, 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 present invention relates to a class of furnaces described in British Letters
Patent No. 22402, dated December 22nd, 1891, in which coal dust or other
pulverulent fuel is consumed; in that Patent, a firing chamber of a cylindrical or
conical form is shown and described, arranged horizontally to be introduced into

page_text: the open end of the fire flue of the boiler to be heated. The fine fuel is blown or
forced into the ignition chamber by the aid of steam or air under pressure or a
mixture of both.
In the present invention, the firing chamber is constructed in the form of an
elbow, having its horizontal arm preferably of a conical shape to fit tightly into
the mouth of the firing flue; whilst the pulverulent fuel is introduced at the top of
the vertical arm. The fuel enters into the firing chamber by gravity, assisted only
by a blast or the natural draught of the chimney.
--
On the accompanying sheet of drawings:-
Figure 1 represents a vertical longitudinal section through the apparatus on the
line 2-2 of Figure 2.
Figure 2, an end view; and
Figure 3, a plan of the same.
The pulverulent fuel is fed into a hopper m' at the top of the vertical arm Z²
of the firing chamber Z, and is caused to fall into the latter in the form of a shower
of fine dust by means of a horizontal circular sieve or grating m, rocking or
oscillating on a vertical axis. This feed grating m also disintegrates the coal dust
that may have become caked. The grating is actuated by the bifurcated arm A¹
of a bell-crank lever, the other arm being in continuous contact with a cam
disc m² secured on the revolving shaft h.
For regulating the introduction of the coal dust into the combustion chamber =,
the stroke of the bell-crank lever k¹² may be controlled by a set screw 7, which
limits the retrograde motion of the lever.
This returning motion is effected with greater velocity than the forward move-
ment caused by the cams m², a suitable spring being provided for the purpose.
The oscillations which then take place, being. of differential velocity, are very
favourable to the disintegration of the fuel.
The shaft may be rotated by any suitable means. To avoid the need of a
special motor, the natural draught of the chimney may be used for driving a little
motor-wheel, as shown in the drawing. For such purpose, a spirally winged wheel b
is placed in the orifice of the tube p entering the chimney and connected with the
shaft by any appropriate gearing.
The shower or spray of coal dust coming from the grating m falls down into the
vertical arm Z2 of the combustion chamber Z. This arm is provided with
horizontal rows of air-supply-channels X, each row communicating with an exterior
annular chamber W, which latter are fed by a common air-supply-pipe Z³ and
provided with regulating valves g. By properly regulating the admission of the
air to the combustion chamber, a perfectly smokeless combustion of the fuel may
be obtained. The whole apparatus is made portable by being mounted on
wheels r.
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 combination, with a disintegrating and supply device for fine fuel, of an
elbow-shaped combustion chamber, horizontal rows of air channels communicating
with exterior annular chainbers, a common air supply pipe and means for regulating
or cutting off the supply of air to each of the annular chambers, substantially as
described and shown.
2. The combination, with an elbow-shaped combustion chamber, air channels
issuing from annular chambers and a common air supply pipe, of a bell-crank lever
for actuating a rocking disintegrator, a rotating cam and a spring, both moving to
and fro the lever, and a set screw limiting the stroke of the lever, substantially
as set forth.
3. The combination, with an elbow-shaped combustion chamber for fine fuel, of
a spirally winged motor-wheel, mounted in the orifice of a pipe, communicating

page_text: with the chimney, and driven by the draught of the latter, and suitable means for
transferring the rotation of the motor-wheel to the cam-shaft, substantially as set
forth.
Dated this 26th day of April 1893.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.