An Improved Mixing and Feeding Apparatus for Coal-dust Furnaces.
Year: 1896

page_text: Date of Application, 19th May, 1896
Complete Specification Left, 19th Feb., 1897-Accepted, 10th Apr., 1897
PROVISIONAL SPECIFICATION.
An Improved Mixing and Feeding Apparatus for Coal-dust
Furnaces.
I, FRANZ FORST, of 28 Judengasse, Strassburg i.E., Alsace, in the Empire of
Germany, Inventor, do hereby declare the nature of this invention to be as
follows:-
My invention relates to a mixing and feeding apparatus for coal-dust furnaces, in
which the fuel is spread like a veil by having to pass through slots between vanes or
blades on wheels placed one upon the other and turned in the same manner; the
mixing with air being facilitated by other vanes or blades arranged in the mixing
chamber for the production of whirls.
Upon the vertical cylinder or casing I provide an upper and a lower opening. At
the top I fix a hopper to receive the fuel. To the cylinder a suitable vertical shaft
extends from below and is held or supported by a footstep bearing, the said shaft is
provided with a toothed wheel and a worm running in a vertical tube fixed inside
vertical cylinder. The tube is free to rotate on ball bearings in a frame at the top and
bottom of the casing.
The vertical tube or pipe carries upon the upper face a vane wheel with blades.
Above this wheel is another vane wheel carried on the shaft and is provided at the
concave edges of the blades with teeth bent upwards.
The two vane wheels together form on plan crescent slots or apertures, and may be
displaced relatively to each other for the purpose of increasing or diminishing the size
of the slots; for this purpose a latch or catch is hinged to the vertical tube which
engages with a toothed wheel keyed on the shaft so as to form a rigid connection
between the shaft and tube and to admit of adjustment of vane wheels.
Below the toothed wheel I provide an air funnel carried by supporting arms
(or in any other convenient manner) in which funnel a fan is keyed to the shaft to
revolve.
A pulley is fixed to the shaft for actuating the device by an endless band.
The vertical tube is for the purpose of admitting air into the casing of the
apparatus.
In the interior wall or surface of the vertical cylinder or casing I arrange as vanes
several bent plates which are for the purpose of producing whirls when the apparatus
is in motion.
If preferable a funnel shaped bottom may be used with a door at the base to enable
the large pieces of fuel (not in the form of dust) to be removed.
To facilitate the sliding of the coal-dust down up the vane wheels I insert into the
bottom of the hopper a conical cap which is carried by arms riveted to the hopper.
The discharge pipe for the mixture of air and coal-dust is arranged tangentially to
the case above the bottom.
A throttle vale is fitted in the discharge channel in order to regulate the flow of
material.
The mode of operation is as follows:-
The apparatus is driven by the pulley which revolves the shaft, fan, tube and the
vane wheels after the vane wheels have been adjusted. The air wheel or fan draws in
air and forces it through the pipe into the casing. The serrated edges of the vane

page_text: wheel force the coal-dust deposited upon the said edges downwards in quantities
limited by the width of the slots and throw it veil-like into the casing when the
air entering through tube and the slots is mixed with the same. The fuel then
passes to the furnace through the tangential branch or discharge pipe.
Dated this 19th day of May 1896.
J. P. BAYLY,
18 Fulham Place, London, W., Agent for the Applicant.
COMPLETE SPECIFICATION.
An Improved Mixing and Feeding Apparatus for Coal-dust
Furnaces.
1, FRANZ FORST, of 28 Judengasse, Strasburg, Alsace, in the Empire of Germany,
Inventor, 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 stateinent :-
This invention relates to a mixing and feeding apparatus for coal-dust furnaces,
in which the fuel is spread like a veil by having to pass through slots between the
vanes or blades of vane wheels placed one upon the other and turned in the same
manner, the mixing with suitably admitted air being facilitated by other vanes or
blades appropriately arranged in the mixing chamber for the production of whirls.
The accompanying drawings represents a constructional form of the invention by
way of example.
Upon the cylindrical vessel or casing a of the apparatus provided with an upper
and a lower opening, (of which Fig. 1, represents a vertical central section and
Fig. 2, a horizontal section) I fix a feeding funnel or hopper 6 for the dust-like
fuel. A suitably supported shaft c extends from below the cylindrical casing a and
is held or supported by the box or footstep bearing e, the toothed wheel kand the
worm f, in an air admission pipe g which in its turn is supported so as to be
free to rotate on ball bearings on a frame h at the upper end, and on the bottom h¹
of the cylindrical casing a at its lower end.
The pipe g carries upon an upper front face the vane wheel d' the vanes or
blades of which present the form shown in Fig. 3.
Above this wheel is the vane
wheel d. This is carried by the shaft c and is provided at the concave edges of
the vanes with serrations or teeth which, as shown in Fig. 1, are bent or extend
upwards.
The two vane wheels together form in plan free crescent slots or apertures, and
may be displaced relatively to each other for the purpose of increasing or diminishing
the sizes of the said slots. For this purpose a latch or catch is hinged to the
pipe 9 and is adapted to engage with a toothed wheel k keyed upon the shaft c
and a nut and so to establish a rigid connection between the shaft c and pipe g,
+2
and at the same time to permit of an adjustment of the size of the slots on the
vane wheels d and d being readily effected.
Below the toothed wheel k I provide an air funnel g' carried by supporting
arms or in any other convenient manner, in which funnel g'a fan w keyed upon
the shaft c is adapted to turn.
A disc or pulley s secured upon the shaft c below the fan w serves for actuating the
device.
The pipe g is for the purpose of admitting air into the cylindrical casing and for
that purpose is provided in that part situated within the said cylindrical case with
slots o which may if desired be arranged in helical convolutions, and through which
the compressed air is admitted to the said cylindrical casing.

page_text: the interior wall or surface of the cylindrical casing
and I, which are for the purpose of producing whirls
Between the slots o and on
I arrange as vanes the plates
in the said cylindrical casing.
In lieu of a horizontal bottom the cylindrical casing may be provided with a funnel
shaped bottom; in this latter case it is expedient to provide a door in the bottom in
order to enable the large pieces of coal or other admixtures, such as are not in the
form of dust, of the faul to be removed.
To facilitate the sliding of the coal-dust down upon the vane wheels I insert into the
bottom of the funnel or hopper b a conical cap r which is carried by arms r riveted
to the said funnel or hopper."
The discharge pipe for the mixture of air and coal-lust, which is arranged
tangentially to the shell of the cylindrical casing is placed above the bottom of the
latter in such a manner that comparatively large pieces of coal and other admixtures
which are not in the form of dust will not be able to pass into the discharge pipe.
In order that the admission of the mixture to the furnace may be regulated I fit
a throttle valve in the discharge channel for the mixture.
The vessel or cylindrical casing a may be supported upon another cylinder
extending to the bottom and furnished with a door for purposes of access, or it
may be supported upon feet.
The mode of operation is as follows:
The apparatus is actuated by the disc or pulley as, that is to say the shaft with
the fan w, the pipe y with the vane wheels dare set in rotary motion which
latter wheels have to be previously adjusted by means of the lever for the requisite
quantity to be admitted.
The air wheel or fan to draws in air and forces it through the pipe into the
vessel or cylindrical casing a. The serrated edges of the vane wheel d², by reason
of their rotary movements, force the coal dust deposited upon the said edges
downwards, in quantities limited by the width of the slots i adjusted by them, and
throw it veil-like into the cylindrical casing where the air entering through the
pipe g and at the slots o is mixed with the same.
The fuel produced in this manner passes out of the cylindrical casing through
the tangential branch or discharge pipe and is conducted to the furnace.
An alternate form as it is carried out of the aforesaid apparatus is shown in the
accompanying drawings as follows:-
Fig. 4, is a vertical section.
Fig. 5, is a horizontal section.
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Figs. 6, and 7, shows the different arrangements of the feeding pipe.
Fig. 8, shows the use of the wind-wheel or fan as a means of working.
Underneath the funnel or hopper a designed for the reception of the coal dust
is arranged a feeding mechanism consisting of two adjustable winged discs & &,
lying radial to each other they are of a different shape; whilst the bent rims y
of the wings of the dise form knives extending with their cutting edges upwards,
the disc has slots which may be covered more or less by the wings of the
dise by a rotary movement of the said discs relatively to each other. Both discs
are fastened, to its hollow shait which are arranged concentrically with respect to
one another, and in such a manner that the disc b' will be located at the top. By
means of the arrangement at the lower end of the outer hollow shaft the discs
are adjustable to each other, whereby the feeding is regulated.
The action of the feeling dises is as follows:-The hopper or funnel is shut off
by the same at its lower end. By the sinking down of the coal dust in the funnel
upon the discs one of which lies on the top of the other and the wings of which are
standing at an unequal height columns of dust are formed on the lower disc b
between the wings of the disc 17. Should the said discs be now caused to rotate
by the shaft the knives of the disc b will cut off these columns of dust and this
mass of dust is thrown through the slots of the disc into the mixing room or
compartment c².
The coal dust is here thoroughly mixed with air for combustion in a suitable

page_text: and then
according
manner by a spread or mushroom shaped dise d and mixing wings
conducted into the furnace chamber through a tangential or radial pipe
to the arrangement of the apparatus and proportionately formed to the size of the
mixing room or compartment.
The operation of the apparatus may be effected by pulleys or by means of the
draft of a chimney using a wind wheel wº.
In the latter case the arrangement of an air case with an assistant pipe h is
provided as shown in Fig. 5.
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 mixing and feeding device for coal dust furnaces, the combination of the
various parts so that the fuel, by having to pass through adjustable slots or apertures
between the vanes of two vane wheels d' d placed one above the other and
rotating at the same velocity, is spread out in a veil-like manner, the mixing with
suitably admitted air being promoted by vanes which are arranged in an
appropriate manner in the mixing chamber for the production of whirls, substantially
as herein described and according to the accompanying drawings.
2. In a mixing and feeding apparatuses for coal dust furnaces, the combination
of the various parts described in the above specification for the purpose specified.
3. In a mixing and feeding apparatuses for coal dust furnaces, the combination
of the various parts described in the above specification and illustrated in the
accompanying drawings.
Dated this 19th day of February 1897
J. P. BAYLY,
18 Fulham Place, London, W., Agent for the Applicant.