Improvements in Furnaces.
Year: 1892

page_text: .Date of Application, 14th July, 1892
Complete Specification Left, 3rd Nov., 1892-Accepted, 3rd Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Furnaces.
I, EDWARD GRIFFITH BREWER, of 33 Chancery Lane, London, and 30 East
Parade, Leeds, in the County of York, Fellow of the Chartered Institute of Patent
Agents, do hereby declare the nature of this invention to be as follows (which
invention has been communicated to me from abroad by La Societé E. Herrmann
& Cohen of 42 Boulevard Bonne Nouvelle, Paris, France, Engineers)
The present application for Patent for an invention has for its object
improvements made in furnaces patented in England the 6th June 1887 No. 8110,
and the 3rd July 1890, No. 10398.
The improvements refer,
Firstly, to a movable upper grate.
Secondly, to the foot grate.
Thirdly, to the feed hopper.
Movable grate. This grate has almost its original form, but instead of being
moved at the bottom or lower part as formerly, which renders the fall of the fuel
less easy, especially when large coal is employed, it is provided at its lower part
with trunnions which rest on carriers formed in the sides of the furnace.
This same grate is provided with an operating handle. It results from the
arrangements about to be indicated that when this operating handle is pushed from
the front to the rear, the grate turns on its trunnions describing an arc of a circle in
the space by its upper part, the said axis being at the lower part of the grate
instead of being placed at the top of the furnance as formerly.
Thus, as will be readily understood, the coals are by this means driven directly
towards the bottom, so that their descent on the lower grate is obtained without
possible accumulation at this grate, and the employment of the pusher for this
descent is no longer indispensable.
The foot grate, or the grate on which the combustible fuel rests, instead of being
so formed, at the back part with slots between the bars towards the rear, as
formerly, is now slightly or somewhat concave with slots between the bars,
mounting or ascending towards the rear. The object of this arrangement is to
facilitate the stirring up of the fuel by the stoker. He passes his poker or stirrer
between the space of the large grate and the foot grate to detach the clinkers
which have there accumulated, and then he is able to withdraw them easily with a
hook owing to the shape of the foot grate.
The charging hopper. In order to regulate the introduction of fuel into the
furnace in proportion to its quality or otherwise, such as its burning power, and also
to permit of diminishing the consumption during the time the furnace may be
damped down, there is provided a charging hopper with a plate jointed at its upper
part and having the same breadth as the said hopper.
This plate is provided with a sector arm bored with holes, and which passes
through the side of the hopper in such manner that when the exit orifice of the said
hopper is to be enlarged or made smaller, the sector arm is drawn and fixed in the
desired position by means of a pin passed through one of these holes. It is evident
that this last arrangement is only given as an example, the same result being able
to be obtained by other means.
In some cases the upper grate need not be made movable, which has for object
to effect the evaporation of moisture of the coal, and to advance from time to time
the dried portions of the said coal or fuel. The bars of this grate now remain
fixed, their upper ends entering into a cross piece, and their lower ends -hooking
onto a lower plate.

page_text: The introduction of coal is effected by incans of a rotary feeder placed below the
hopper. The section of this feeder has the form of a star with three or four arms,
which form wings, the generatrices of which are parallel or inclined as a screw in
relation to the axis; the axis of the feeder is furnished with a toothed wheel with
endless screw or worm, which is turned periodically by hand or in a constant manner
by means of any suitable motive power.
Another improvement added to this furnace consists in a modification of the main
grate and foot grate. This latter is more inclined.
The position of the axis of the main grate is moved and a turning grate is placed
between the two; this grate rests alinost vertically during the working, but it can
be lowered down for stirring up the fuel. For this purpose it turns about a centre.
The arms, when the grate is opened, touch the furnace bed in such manner that the
grate is retained in position and thus forms a sort of platform. The lower ends of
the main grate and the upper ends of the turning grate are formed in such manner
that the combustion takes place at this point in the same manner as at the other
parts of the grate, this arrangement preventing all combustion of the bars at the
place where they join or their points of juncture. During the stirring up of the
foot grate the poker can be applied on the bars of this graie above the bed for well
breaking the clinkers.
Dated this 14th day of July 1892.
BREWER & SON,
Agents.
I, EDWARD GRIFFITH BREWER, of 33 Chancery Lane, London, and 30 East
Parade, Leeds, in the County of York, 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, (which invention has been communicated to me from abroad
by La Societé E. Herrmann & Cohen, of 42 Boulevard Bonne Nouvelle, Paris,
France, Engineers).
% This invention refers to improvements in furnaces wherein triple grates are
employed, all as hereafter described. The invention will be readily understood
by the following description referring to the accompanying drawings, in which
Fig. 1 represents a section through one of the furnaces constructed according to
this invention being provided with a rotary feeder and with a turning grate placed
between a large grate and a foot grate.
Fig. 2 is a section through a b of Fig. 1, 'shewing the driving gear of the rotary
feeder.
Fig. 3. is a section through c d of Fig. 1, shewing a partial face view of the
turning grate.
According to this invention the furnace comprises three distinct grates BC
and D surmounted by a hopper A, say of cast iron (Fig. 1). The principal
grate C is inclined at about an angle of 45 degrees, and is formed with independent
bars of cast iron, resting at their lower parts on a bed or bar and at their upper
These bars C have a great
parts on a shaft m, carried by cast iron arms M M.
height in order to facilitate their cooling by the air traversing the grate; they
have on each face a rib at their lower part to maintain the distance apart, and at
their upper part there are three or four ribs situated on the two faces of the bar, in
order to maintain the distancing at the top.
The foot grate D receives the ashes it rests at the rear on a cast iron bed R
supported by the refractory bricks forming the alter of the fireplace, and the
grate D rests at front on an iron crosspiece S built into the lateral masonry.

page_text: The turning grate is situated as indicated in Fig. 1 between the large grate C
and the foot grate D. This grate G normally stands almost vertically, but it can
be lowered for cleaning. For this purpose it is capable of being turned about a
centre to the position shewn in dotted lines, when the arms G₁ rest against the
bed S (Figs. 1 and 3) in such manner that the grate G forms a kind of platform.
The lower ends of the large grate C and the upper ends of the turning grate Gare
formed in such manner that the combustion takes place at this point in the same
equal manner as at the other parts of the grate and thereby combustion of the
bars at the point of their junction is prevented.
During the cleaning of the foot grate D, the scraper or rake can be applied on
the bars of this grate at the top of the bed S for breaking up the clinkers.
The bars of the upper grate B adjoin by side flanges on a part of their length to
limit the passage of air in this place.
These bars B are fixed, their upper ends entering a crosspiece p, and their lower
ends taking onto the rib of the plate g.
The introduction of coal or fuel is effected by a rotary supply or feed R. placed
below the hopper A. The section of this supply has the form of a three armed
star, or a star with four rays may be employed, the rays being in the form of blades,
the generatrices of which are parallel or inclined in screw form in relation to the
axis. This axis is furnished with a toothed wheel M* with endless screw N, Fig. 2,
which is turned either periodically by hand or in a regular manner by means of
motive power.
At the same height as the upper grate B, there is a heading of refractory fire-
brick E, and on the side there are air inlets G2 the air can also penetrate by the
bars of the upper grate B through orifices and under the grate G by a butterfly
valve situated on the doors of the furnace, but these two air inlets are separated by
the diaghragm plate y in order to render the regulation of the air entrances to the
furnace independent the one of the other. The apparatus is enclosed in a
rectangular casing, formed, say, in cast iron, and lined internally with fire brick
supported at the front and upper part by suitable crosspieces and supports of, say,
cast iron. At the front part there are one, or may be two, doors according to the
length or size of the furnace. The refractory arch E rests on the sides of the
fireplace.
The charging of fuel is accomplished through the hopper A, which is provided
on its front face with two plates, between which the attendant may introduce a tool
or iron to assure the regular descent of the fuel on the whole breadth of the fire-
place, and thus avoid any obstruction at the lower part of the hopper.
On account of the height of the apparatus, and in order not to interfere with the
cleaning of the boilers or of the tubes of the boiler, this hopper can be completely
brought down to the front of the fireplace by turning it about the axis f, Fig. 1.
The fuel falls from the hopper A on to the upper grate B; it is there submitted
to the radiating heat of the arch E, whereby the combustible gases become dis-
engaged, and are mixed with the air passing through the grate B and also arriving
by the lateral orifices G above the layer of the fuel. The air thus entering in the
two perpendicular directions produces breaking up of the gases and an interinixture
of the volatile matters proceeding from the fuel, and this mixture by reason of the
draft of the chimney, passes the arch E and is maintained at a. very high tem-
perature, and the incandescent mass coming on the large grate C, the combustion
of these gaseous products is thereby assured.
The combustion then takes place on the grate C as on an ordinary grate, but
only coke falls thereon, and the fine parts of the fuel employed arrive there already
agglomerated.
The ciuders and clinkers are only produced at the bottom of the grate C and on
the foot grate D, whence it is easy to remove them. The doors of the ashpit
should remain closed a normal time; their valve alone is opened, as well as the
opening g, but these openings should be regulated according to the draft of the
chimney, the nature of the fuel, and the quantity of vapour to be produced.

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 furnaces, a rotary supply device R having a star section composed of
several radiating blades or arms, the said supply device receiving the coal directly
from the hopper A and advancing it towards the firebrick arch of the furnace,
substantially as and for the purposes sét forth.
2. In furnaces, the arch construction composed of firebrick and forming a chamber
in which the fuel is subjected to the action of heat to which chamber at the same
time regulated currents of air are admitted, all substantially as and for the purposes
set forth.
3. In furnaces, the combination of the arch construction X with the grate B
where the coal is retained for submitting it to the action of heat and where the
combustion of the gaseous products thereof is effected, air therefor being admitted
by the aperture in front of the grate B and by the lateral orifices G³, these two
entries of air in directions at right angles, assuring the thorough breaking up of
the gaseous products, all constructed and acting substantially as and for the purposes
herein described.
4. In furnaces, the arrangement of a movable grate G, capable of being lowered
down and forming a platform, and when in its raised position retaining the fuel,
the said grate G being disconnected from the large grate in such manner as to
allow an equal combustion at this place as in any other part of the grate G, all
constructed and acting substantially as and for the purposes set forth.
5. In furnaces, the combination therewith of the rotary supply device receiving
the fuel direct from the hopper A and feeding same in a regular manner in front
of the arch or heating chamber, the latter having an air access to render complete
the utilization of the gases produced in this chamber, all constructed and acting
substantially as and for the purposes herein described.
6. In furnaces, the combination with a swinging grate to permit of access into
the fireplace throwing it below the fire with a double movable grate forming a
continuation of the fires without interruption and forming a platform when it is
lowered down, all substantially as and for the purposes herein described.
7. In furnaces, the combination with the various arrangements before referred to
for the rotary supply of the heating chamber with the suitable air entries, of the
swinging grate, the continuous movable grate, whereby the combustion is divided
into two distinct phases, Firstly, heating and combustion of the evolved gaseous
products; Secondly, combustion of the cokes all substantially as herein described
and illustrated with reference to the accompanying drawings.
8. The general arrangement and combination of parts composing the herein
described improvements in furnaces, all constructed and acting substantially as and
for the purposes set forth with reference to the accompanying drawings.
Dated this 3rd day of November 1892.